Salvatore Santamaria

Dr Salvatore Santamaria


Lecturer in Cardiovascular Science
PhD, MSc, BSc (Hons)

Academic and research departments

Department of Biochemical Sciences.

Research

Research interests

Publications

Daniel R. Martin, Salvatore Santamaria, Christopher D. Koch, Josefin Ahnstrom, Suneel S. Apte (2021)Identification of novel ADAMTS1, ADAMTS4 and ADAMTS5 cleavage sites in versican using a label-free quantitative proteomics approach, In: Journal of proteomics249pp. 104358-104358 Elsevier

The chondroitin sulfate proteoglycan versican is important for embryonic development and several human disorders. The versican V1 splice isoform is widely expressed and cleaved by ADAMTS proteases at a well-characterized site, Glu(441)-Ala(442). Since ADAMTS proteases cleave the homologous proteoglycan aggrecan at multiple sites, we hypothesized that additional cleavage sites existed within versican. We report a quantitative label-free approach that ranks abundance of liquid chromatography-tandem mass spectrometry (LC-MS/MS)identified semi-tryptic peptides after versican digestion by ADAMTS1, ADAMTS4 and ADAMTS5 to identify site-specific cleavages. Recombinant purified versican V1 constructs were digested with the recombinant full-length proteases, using catalytically inactive mutant proteases in control digests. Semi-tryptic peptide abundance ratios determined by LC-MS/MS in ADAMTS:control digests were compared to the mean of all identified peptides to obtain a z-score by which outlier peptides were ranked, using semi-tryptic peptides identifying Glu(441)-Ala(442) cleavage as the benchmark. Tryptic peptides with higher abundance in control digests supported cleavage site identification. We identified several novel cleavage sites supporting the ADAMTS1/4/5 cleavage site preference for a P1-Glu residue in proteoglycan substrates. Digestion of proteins in vitro and application of this z-score approach is potentially widely applicable for mapping protease cleavage sites using label-free proteomics. Significance: Versican abundance and turnover are relevant to the pathogenesis of several human disorders. Versican is cleaved by A Disintegrin-like And Metalloprotease with Thrombospondin type 1 motifs (ADAMTS) family members at Glu(441)-Ala(442), generating a bioactive proteoform called versikine, but additional cleavage sites and the site-specificity of individual ADAMTS proteases is unexplored. Here, we used a label-free proteomics strategy to identify versican cleavage sites for 3 ADAMTS proteases, applying a novel z-score-based statistical approach to compare the protease digests of versican to controls (digests with inactive protease) using the known protease cleavage site as a benchmark. We identified 21 novel cleavage sites that had a comparable z-score to the benchmark. Given the functional significance of versikine, they represent potentially significant cleavages and helped to refine a substrate site preference for each protease.The z-score approach is potentially widely applicable for discovery of site-specific cleavages within an purified protein or small ensemble of proteins using any protease.

Salvatore Santamaria, Daniel R. Martin, Xiangyi Dong, Kazuhiro Yamamoto, Suneel S. Apte, Josefin Ahnström (2021)Post-translational regulation and proteolytic activity of the metalloproteinase ADAMTS8, In: The Journal of biological chemistry297(5)101323pp. 101323-101323 Elsevier Inc

A disintegrin-like and metalloprotease domain with thrombospondin type 1 motifs (ADAMTS)8 is a secreted protease, which was recently implicated in pathogenesis of pulmonary arterial hypertension (PAH). However, the substrate repertoire of ADAMTS8 and regulation of its activity are incompletely understood. Although considered a proteoglycanase because of high sequence similarity and close phylogenetic relationship to the proteoglycan-degrading proteases ADAMTS1, 4, 5, and 15, as well as tight genetic linkage with ADAMTS15 on human chromosome 11, its aggrecanase activity was reportedly weak. Several post-translational factors are known to regulate ADAMTS proteases such as autolysis, inhibition by endogenous inhibitors, and receptor-mediated endocytosis, but their impacts on ADAMTS8 are unknown. Here, we show that ADAMTS8 undergoes autolysis at six different sites within its spacer domain. We also found that in contrast to ADAMTS4 and 5, ADAMTS8 levels were not regulated through low-density lipoprotein receptor-related protein 1 (LRP1)-mediated endocytosis. Additionally, ADAMTS8 lacked significant activity against the proteoglycans aggrecan, versican, and biglycan. Instead, we found that ADAMTS8 cleaved osteopontin, a phosphoprotein whose expression is upregulated in PAH. Multiple ADAMTS8 cleavage sites were identified using liquid chromatography–tandem mass spectrometry. Osteopontin cleavage by ADAMTS8 was efficiently inhibited by TIMP-3, an endogenous inhibitor of ADAMTS1, 4, and 5, as well as by TIMP-2, which has no previously reported inhibitory activity against other ADAMTS proteases. These differences in post-translational regulation and substrate repertoire differentiate ADAMTS8 from other family members and may help to elucidate its role in PAH.

Priyanka Hirani, Jacqueline McDermott, Vinothini Rajeeve, Pedro Cutillas, J Louise Jones, Daniel J Pennington, Thomas N Wight, Salvatore Santamaria, Kimberly M Alonge, Oliver M T Pearce (2024)Versican Associates with Tumor Immune Phenotype and Limits T-cell Trafficking via Chondroitin Sulfate, In: Cancer research communications4(4)pp. 970-985 AACR

Immunotherapies for cancers of epithelial origin have limited efficacy, and a growing body of evidence links the composition of extracellular matrix (ECM) with the likelihood of a favorable response to treatment. The ECM may be considered an immunologic barrier, restricting the localization of cytotoxic immune cells to stromal areas and inhibiting their contact with tumor cells. Identifying ECM components of this immunologic barrier could provide targets that whether degraded in situ may support antitumor immunity and improve immunotherapy response. Using a library of primary triple-negative breast cancer tissues, we correlated CD8+ T-cell tumor contact with ECM composition and identified a proteoglycan, versican (VCAN), as a putative member of the immunologic barrier. Our analysis reveals that CD8+ T-cell contact with tumor associates with the location of VCAN expression, the specific glycovariant of VCAN [defined through the pattern of posttranslational attachments of glycosaminoglycans (GAG)], and the cell types that produce the variant. In functional studies, the isomers of chondroitin sulfate presented on VCAN have opposing roles being either supportive or inhibiting of T-cell trafficking, and removal of the GAGs ameliorates these effects on T-cell trafficking. Overall, we conclude that VCAN can either support or inhibit T-cell trafficking within the tumor microenvironment depending on the pattern of GAGs present, and that VCAN is a major component of the ECM immunologic barrier that defines the type of response to immunotherapy. Significance: The response to immunotherapy has been poor toward solid tumors despite immune cells infiltrating into the tumor. The ECM has been associated with impacting T-cell infiltration toward the tumor and in this article we have identified VCAN and its structural modification, chondroitin sulfate as having a key role in T-cell invasion.

Salvatore Santamaria (2023)Proteases and Cancer Springer US

This volume details bioinformatics analysis, biochemical assays, recombinant protein expression and purification, methods to investigate protease activity in cell-based, organoids and in vivo systems, proteomics, transcriptomics, machine learning and novel approaches to target dysregulated protease activity in cancer. Written in the highly successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Authoritative and cutting-edge, Proteases and Cancer: Methods and Protocols aims to provide the scientific community with a diverse and representative collection of state-of-the-art methods to investigate the protean functions of proteases in cancer biology.

Salvatore Santamaria (2024)Web-Based Resources to Investigate Protease Function, In: Proteases and Cancer Springer US

In 2001, the release of the first draft of the human genome marked the beginning of the Big Data era for biological sciences. Since then, the complexity of datasets generated by laboratories worldwide has increased exponentially. Public repositories such as the Protein Data Bank, which has exceeded the 200000 entries in 2023, have been instrumental not only to collect, organize, and distill this enormous research output but also to promote further research enterprises. The achievements of artificial intelligence programs such as AlphaFold would not have been possible without the collective efforts of countless researchers who made their work publicly available. Here, I provide a practical, but far from exhaustive, list of resources useful to investigate protease function.

Tina Burkhard, Alexander Frederick Minns, Salvatore Santamaria (2024)Expression and Purification of Recombinant ADAMTS8, In: Proteases and Cancer: Methods and Protocols2747pp. 55-66 Springer

ADAMTS8 (A Disintegrin-like and Metalloproteinase with Thrombospondin motifs 8) is a secreted zinc-dependent metalloproteinase whose expression is downregulated in a variety of solid tumors. Xenografts expressing high levels of ADAMTS8 have a poor capacity to invade and migrate in nude mice. While this data highlights a beneficial, anti-cancerogenic role of ADAMTS8, the mechanism behind this activity is still not fully elucidated. So far, the only reported substrate for ADAMTS8 is osteopontin (OPN), an extracellular matrix protein widely implicated in multiple steps of cancer progression, albeit, similar to other ADAMTS family members, it is very likely that ADAMTS8 cleaves a variety of substrates. The availability of purified ADAMTS8 may enlighten the biological role of this metalloproteinase.Here we describe methods for expression and purification of recombinant ADAMTS8 in HEK293T cells as well as a convenient assay to test ADAMTS8 proteolytic activity using OPN as a substrate.

Alexander Frederick Minns, Yawei Qi, Kazuhiro Yamamoto, Karen Lee, Salvatore Santamaria (2023)The C-terminal domains of ADAMTS1 contain exosites involved in its proteoglycanase activity, In: The Journal of biological chemistry299(4)pp. 103048-103048 Elsevier

A disintegrin-like and metalloproteinase with thrombo-spondin type 1 motifs (ADAMTS1) is a protease involved in fertilization, cancer, cardiovascular development, and thoracic aneurysms. Proteoglycans such as versican and aggrecan have been identified as ADAMTS1 substrates, and Adamts1 ablation in mice typically results in versican accumulation; however, previous qualitative studies have suggested that ADAMTS1 proteoglycanase activity is weaker than that of other family members such as ADAMTS4 and ADAMTS5. Here, we inves-tigated the functional determinants of ADAMTS1 proteogly-canase activity. We found that ADAMTS1 versicanase activity is approximately 1000-fold lower than ADAMTS5 and 50-fold lower than ADAMTS4 with a kinetic constant (kcat/Km) of 3.6 x 103 M-1 s-1 against full-length versican. Studies on domain-deletion variants identified the spacer and cysteine-rich domains as major determinants of ADAMTS1 versicanase ac-tivity. Additionally, we confirmed that these C-terminal do-mains are involved in the proteolysis of aggrecan as well as biglycan, a small leucine-rich proteoglycan. Glutamine scan-ning mutagenesis of exposed positively charged residues on the spacer domain loops and loop substitution with ADAMTS4 identified clusters of substrate-binding residues (exosites) in 113-114 (R756Q/R759Q/R762Q), 119-1110 (residues 828-835), and 116-117 (K795Q) loops. This study provides a mechanistic foundation for understanding the interactions between ADAMTS1 and its proteoglycan substrates and paves the way for development of selective exosite modulators of ADAMTS1 proteoglycanase activity.

Alexander Frederick Minns, Salvatore Santamaria (2024)Determination of Versikine Levels by Enzyme-Linked Immunosorbent Assay (ELISA), In: Proteases and Cancer: Methods and Protocols2747pp. 83-93 Springer

The proteoglycan versican plays multiple roles in cancer progression, from promoting cell invasion and proliferation to evasion of immune surveillance. Metalloproteinases of the A Disintegrin and Metalloproteinase with Thrombospondin-like motif (ADAMTS) family cleave versican at a specific Glu-Ala bond, thus releasing a bioactive fragment named versikine, whose biological function, still not entirely revealed, seems that of antagonizing the effects of the parental molecule. Here we describe an enzyme-linked immunosorbent assay (ELISA) that specifically detects versikine in media, pure component systems, and biological fluids using neoepitope antibodies. Such antibodies recognize their target proteolytic fragment but not the intact, parental molecule. Versikine fragments are captured by neoepitope antibodies and detected by antibodies directed against its N-terminal globular (G1) domain. The method here described can therefore be used to measure ADAMTS versicanase activity and provides a quantitative alternative to immunoblotting.

Hang Fai Kwok, Kazuhiro Yamamoto, Rens de Groot, Simone Dario Scilabra, Salvatore Santamaria (2023)Editorial: ADAM, ADAMTS and astacin proteases: Challenges and breakthroughs in the -Omics era-Volume II, In: Frontiers in molecular biosciences10pp. 1172288-1172288 Frontiers Media S.A
Marsioleda Kemberi, Yousuf Salmasi, Salvatore Santamaria (2023)The Role of ADAMTS Proteoglycanases in Thoracic Aortic Disease, In: International journal of molecular sciences24(15) MDPI

Thoracic aortic aneurysm and dissection (TAAD) are complex disease states with high morbidity and mortality that pose significant challenges to early diagnosis. Patients with an aneurysm are asymptomatic and typically present to the emergency department only after the development of a dissection. The extracellular matrix (ECM) plays a crucial role in regulating the aortic structure and function. The histopathologic hallmark termed medial degeneration is characterised by smooth muscle cell (SMC) loss, the degradation of elastic and collagen fibres and proteoglycan (PG) accumulation. Covalently attached to the protein core of PGs are a number of glycosaminoglycan chains, negatively charged molecules that provide flexibility, compressibility, and viscoelasticity to the aorta. PG pooling in the media can produce discontinuities in the aortic wall leading to increased local stress. The accumulation of PGs is likely due to an imbalance between their synthesis by SMCs and decreased proteolysis by A Disintegrin-like and Metalloproteinase with Thrombospondin motifs (ADAMTS) proteoglycanases in the ECM. Mouse models of TAAD indicated that these proteases exert a crucial, albeit complex and not fully elucidated, role in this disease. This has led to a mounting interest in utilising ADAMTS proteoglycanases as biomarkers of TAAD. In this review, we discuss the role of ADAMTSs in thoracic aortic disease and their potential use in facilitating the clinical diagnosis of TAAD and disease progression.

Salvatore Santamaria (2020)Chemical Modification of Proteoglycanases with Biotin, In: S S Apte (eds.), ADAMTS Proteasespp. 113-123 Humana Press Inc

Biotinylation is a versatile technique that has been used to label proteins for a variety of applications. Under alkaline conditions, the N-hydroxylsuccinimide (NHS) ester present on the biotinylation reagent reacts with primary amines such as the side chain of lysine residues or the N-termini of proteins to yield stable amide bonds. However, the effect of biotinylation on enzyme structure and function has not been generally appreciated. In this chapter, I describe specific issues involving biotinylation of proteoglycanases (e.g., ADAMTS-1, -4, and -5). Taking ADAMTS-5 as an example, I show how high incorporation of biotin molecules causes a decrease in aggrecanase activity, most likely by disrupting exosites present in the cysteine-rich and spacer domains. Such an effect is not evident when enzymatic activity is measured with synthetic peptides, since exosites are not strictly required for peptidolytic activity. Therefore, extreme care must be taken when labeling proteoglycanases and the appropriate enzyme/biotin ratio must be determined experimentally for each enzyme.

Salvatore Santamaria, Rens de Groot (2020)ADAMTS proteases in cardiovascular physiology and disease, In: Open biology10(12)pp. 200333-200333 Royal Soc London

The a disintegrin-like and metalloproteinase with thrombospondin motif (ADAMTS) family comprises 19 proteases that regulate the structure and function of extracellular proteins in the extracellular matrix and blood. The best characterized cardiovascular role is that of ADAMTS-13 in blood. Moderately low ADAMTS-13 levels increase the risk of ischeamic stroke and very low levels (less than 10%) can cause thrombotic thrombocytopenic purpura (TTP). Recombinant ADAMTS-13 is currently in clinical trials for treatment of TTP. Recently, new cardiovascular roles for ADAMTS proteases have been discovered. Several ADAMTS family members are important in the development of blood vessels and the heart, especially the valves. A number of studies have also investigated the potential role of ADAMTS-1, -4 and -5 in cardiovascular disease. They cleave proteoglycans such as versican, which represent major structural components of the arteries. ADAMTS-7 and -8 are attracting considerable interest owing to their implication in atherosclerosis and pulmonary arterial hypertension, respectively. Mutations in the ADAMTS19 gene cause progressive heart valve disease and missense variants in ADAMTS6 are associated with cardiac conduction. In this review, we discuss in detail the evidence for these and other cardiovascular roles of ADAMTS family members, their proteolytic substrates and the potential molecular mechanisms involved.

Julie L. H. Madsen, Thomas L. Andersen, Salvatore Santamaria, Hideaki Nagase, Jan J. Enghild, Troels Skrydstrup (2012)Synthesis and Evaluation of Silanediols as Highly Selective Uncompetitive Inhibitors of Human Neutrophil Elastase, In: Journal of medicinal chemistry55(17)pp. 7900-7908 Amer Chemical Soc

Chronic obstructive pulmonary disease (COPD) is an increasing health problem and is estimated to be the fifth leading cause of death in 2020 according to the World Health Organization. Current treatments are only palliative, and therefore the development of new medicine for the treatment of COPD is urgent. Human Neutrophil Elastase (HNE) is a serine protease that is heavily involved in the progression of COPD through inflammatory breakdown of lung tissue. Consequently, inhibitors of HNE are of great interest as therapeutics. In this article, the development of silanediol peptide isosters as inhibitors of HNE is presented. Kinetic studies revealed that incorporation of a silanediol isoster in the inhibitor structure resulted in an uncompetitive mechanism of inhibition, which further resulted in excellent selectivity. The peculiar mechanism of inhibition and the resulting selectivity makes the presented inhibitors promising leads for the development of new FINE-inhibitor-based therapeutics for the treatment of COPD.

Marta P. Carrasco, Eva A. Enyedy, Natalia I. Krupenko, Sergey A. Krupenko, Elisa Nuti, Tiziano Tuccinardi, Salvatore Santamaria, Armando Rossello, Adriano Martinelli, M. Amelia Santos (2011)Novel Folate-Hydroxamate Based Antimetabolites: Synthesis and Biological Evaluation, In: Medicinal chemistry (Shp-sariqah, United Arab Emirates)7(4)pp. 265-274 Bentham Science Publ Ltd

A set of hydroxamate derivatives of folic acid and methotrexate (MTX) was synthesized and evaluated for the inhibitory activity against histone deacetylase (HDAC) and dihydrofolate reductase (DHFR), two enzymes overexpressed in metastasizing tumors. The synthesized compounds were further screened for their antiproliferative activity in two human cancer cell lines, A549 (non-small cell lung carcinoma) and PC-3 (prostate adenocarcinoma). All derivatives showed significant inhibitory activity against HDACs (micromolar range) while only the MTX derivative was reasonably effective in DHFR inhibition. A docking study provided insight into the binding mode of the most potent inhibitor in the active sites of the enzymes, allowing rationalization of the bioassays. The MTX-based compound could be of interest for testing against metastasizing tumors in an animal model. The studied derivatives represent promising molecular templates for further development of dual activity anti-cancer drugs. [GRAPHICS] .

Kazuhiro Yamamoto, Rens de Groot, Simone Dario Scilabra, Hang Fai Kwok, Salvatore Santamaria (2021)Editorial: ADAM, ADAMTS and Astacin Proteases: Challenges and Breakthroughs in the -Omics Era, In: Frontiers in molecular biosciences8pp. 780242-780242 Frontiers Media S.A
Salvatore Santamaria, Doretta Cuffaro, Elisa Nuti, Lidia Ciccone, Tiziano Tuccinardi, Francesca Liva, Felicia D’Andrea, Rens de Groot, Armando Rossello, Josefin Ahnström (2021)Exosite inhibition of ADAMTS-5 by a glycoconjugated arylsulfonamide, In: Scientific reports11(Jan (E-published))pp. 949-949 Nature Publishing Group UK

ADAMTS-5 is a major protease involved in the turnover of proteoglycans such as aggrecan and versican. Dysregulated aggrecanase activity of ADAMTS-5 has been directly linked to the etiology of osteoarthritis (OA). For this reason, ADAMTS-5 is a pharmaceutical target for the treatment of OA. ADAMTS-5 shares high structural and functional similarities with ADAMTS-4, which makes the design of selective inhibitors particularly challenging. Here we exploited the ADAMTS-5 binding capacity of β- N -acetyl- d -glucosamine to design a new class of sugar-based arylsulfonamides. Our most promising compound, 4b , is a non-zinc binding ADAMTS-5 inhibitor which showed high selectivity over ADAMTS-4. Docking calculations combined with molecular dynamics simulations demonstrated that 4b is a cross-domain inhibitor that targets the interface of the metalloproteinase and disintegrin-like domains. Furthermore, the interaction between 4b and the ADAMTS-5 Dis domain is mediated by hydrogen bonds between the sugar moiety and two lysine residues (K532 and K533). Targeted mutagenesis of these two residues confirmed their importance both for versicanase activity and inhibitor binding. This positively-charged cluster of ADAMTS-5 represents a previously unknown substrate-binding site (exosite) which is critical for substrate recognition and can therefore be targeted for the development of selective ADAMTS-5 inhibitors.

Doretta Cuffaro, Lidia Ciccone, Armando Rossello, Elisa Nuti, Salvatore Santamaria (2022)Targeting Aggrecanases for Osteoarthritis Therapy: From Zinc Chelation to Exosite Inhibition, In: Journal of medicinal chemistry65(20)pp. 13505-13532 American Chemical Society

Osteoarthritis (OA) is the most common degenerative joint disease. In 1999, two members of the A Disintegrin and Metalloproteinase with Thrombospondin Motifs (ADAMTS) family of metalloproteinases, ADAMTS4 and ADAMTS5, or aggrecanases, were identified as the enzymes responsible for aggrecan degradation in cartilage. The first aggrecanase inhibitors targeted the active site by chelation of the catalytic zinc ion. Due to the generally disappointing performance of zinc-chelating inhibitors in preclinical and clinical studies, inhibition strategies tried to move away from the active-site zinc in order to improve selectivity. Exosite inhibitors bind to proteoglycan-binding residues present on the aggrecanase ancillary domains (called exosites). While exosite inhibitors are generally more selective than zinc-chelating inhibitors, they are still far from fulfilling their potential, partly due to a lack of structural and functional data on aggrecanase exosites. Filling this gap will inform the design of novel potent, selective aggrecanase inhibitors.

Elisa Nuti, Francesca Casalini, Salvatore Santamaria, Pamela Gabelloni, Sara Bendinelli, Eleonora Da Pozzo, Barbara Costa, Luciana Marinelli, Valeria La Pietra, Ettore Novellino, M. Margarida Bernardo, Rafael Fridman, Federico Da Settimo, Claudia Martini, Armando Rossello (2011)Synthesis and biological evaluation in U87MG glioma cells of (ethynylthiophene)sulfonamido-based hydroxamates as matrix metalloproteinase inhibitors, In: European journal of medicinal chemistry46(7)pp. 2617-2629 Elsevier Masson SAS

Matrix metalloproteinases (MMPs) are important factors in gliomas since these enzymes facilitate invasion into the surrounding brain and participate in neovascularization. In particular, the gelatinases (MMP-2 and MMP-9), and more recently MMP-25, have been shown to be highly expressed in gliomas and have been associated with disease progression. Thus, inhibition of these MMPs may represent a promising non-cytotoxic approach to glioma treatment. We report herein the synthesis and biological evaluation of a series of 4-butylphenyl(ethynylthiophene)sulfonamido-based hydroxamates. Among the new compounds tested, a promising derivative, 5a, was identified, which exhibits nanomolar inhibition of MMP-2, MMP-9, and MMP-25, but weak inhibitory activity toward other members of the MMP family. This compound also exhibited anti-invasive activity of U87MG glioblastoma cells at nanomolar concentrations, without affecting cell viability. [Display omitted] ► MMP-2, MMP-9 and MMP-25 have been recognized to be highly expressed in gliomas. ► A series of sulfonamido-based hydroxamates was designed and synthesized. ► Derivative 5a was found to have nanomolar activity toward MMP-2, MMP-9 and MMP-25. ► This compound also proved to have anti-invasive activity on U87MG glioma cell line.

S Salvatore, D Cuffaro, E Nuti, L Ciccone, T Tuccinardi, F Liva, F D’Andrea, R De Groot, A Rossello, J Ahnström, Salvatore Santamaria Exosite inhibition of A Disintegrin And Metalloproteinase with Thrombospondin motif (ADAMTS)-5 by a glycoconjugated arylsulfonamide Cold Spring Harbor Laboratory

ADAMTS-5 is a major protease involved in the turnover of proteoglycans such as aggrecan and versican. Its aggrecanase activity has been directly linked to the etiology of osteoarthritis (OA), identifying ADAMTS-5 as a pharmaceutical target for OA treatment. However, most existing ADAMTS-5 inhibitors target its active site and therefore suffer from poor selectivity. Here, using a novel approach, we have designed a new class of sugar-based arylsulfonamide inhibitors, which are selective for ADAMTS-5 through binding to a previously unknown substrate-binding site (exosite). Docking calculations combined with molecular dynamics simulations demonstrated that our lead compound is a cross-domain inhibitor that targets the interface of the metalloproteinase and disintegrin-like domains. Targeted mutagenesis identified disintegrin-like domain residues K532 and K533 as an exosite which is critical for substrate recognition. Furthermore, we show that this exosite acts as major determinant for inhibitor binding and, therefore, can be targeted for development of selective ADAMTS-5 inhibitors.

Salvatore Santamaria, Kazuhiro Yamamoto, Kenneth Botkjaer, Christopher Tape, Michael R. Dyson, John McCafferty, Gillian Murphy, Hideaki Nagase (2015)Antibody-based exosite inhibitors of ADAMTS-5 (aggrecanase-2), In: Biochemical journal471(3)pp. 391-401 Portland Press Ltd

Adamalysin-like metalloproteinases with thrombospondin (TS) motifs (ADAMTS)-5 is the multi-domain metalloproteinase that most potently degrades aggrecan proteoglycan in the cartilage and its activity is implicated in the development of osteoarthritis (OA). To generate specific exosite inhibitors for it, we screened a phage display antibody library in the presence of the zinc-chelating active site-directed inhibitor GM6001 (Ilomastat) and isolated four highly selective inhibitory antibodies. Two antibodies were mapped to react with exosites in the catalytic/disintegrin domains (Cat/Dis) of the enzyme, one in the TS domain and one in the spacer domain (Sp). The antibody reacting with the Sp blocked the enzyme action only when aggrecan or the Escherichia coli-expressed aggrecan core protein were substrates, but not against a peptide substrate. The study with this antibody revealed the importance of the Sp for effective aggrecanolytic activity of ADAMTS-5 and that this domain does not interact with sulfated glycosaminoglycans (GAGs) but with the protein moiety of the proteoglycan. An antibody directed against the Cat/Dis of ADAMTS-5 was effective in a cell-based model of aggrecan degradation; however, the anti-Sp antibody was ineffective. Western blot analysis of endogenous ADAMTS-5 expressed by human chondrocytes showed the presence largely of truncated forms of ADAMTS-5, thus explaining the lack of efficacy of the anti-Sp antibody. The possibility of ADAMTS-5 truncation must then be taken into account when considering developing anti-ancillary domain antibodies for therapeutic purposes.

Alain Colige, Christine Monseur, James T. B. Crawley, Salvatore Santamaria, Rens de Groot (2019)Proteomic discovery of substrates of the cardiovascular protease ADAMTS7, In: The Journal of biological chemistry294(20)pp. 8037-8045 Amer Soc Biochemistry Molecular Biology Inc

The protease ADAMTS7 functions in the extracellular matrix (ECM) of the cardiovascular system. However, its physiological substrate specificity and mechanism of regulation remain to be explored. To address this, we conducted an unbiased substrate analysis using terminal amine isotopic labeling of substrates (TAILS). The analysis identified candidate substrates of ADAMTS7 in the human fibroblast secretome, including proteins with a wide range of functions, such as collagenous and noncollagenous extracellular matrix proteins, growth factors, proteases, and cell-surface receptors. It also suggested that autolysis occurs at Glu-729-Val-730 and Glu-732-Ala-733 in the ADAMTS7 Spacer domain, which was corroborated by N-terminal sequencing and Western blotting. Importantly, TAILS also identified proteolysis of the latent TGF--binding proteins 3 and 4 (LTBP3/4) at a Glu-Val and Glu-Ala site, respectively. Using purified enzyme and substrate, we confirmed ADAMTS7-catalyzed proteolysis of recombinant LTBP4. Moreover, we identified multiple additional scissile bonds in an N-terminal linker region of LTBP4 that connects fibulin-5/tropoelastin and fibrillin-1-binding regions, which have an important role in elastogenesis. ADAMTS7-mediated cleavage of LTBP4 was efficiently inhibited by the metalloprotease inhibitor TIMP-4, but not by TIMP-1 and less efficiently by TIMP-2 and TIMP-3. As TIMP-4 expression is prevalent in cardiovascular tissues, we propose that TIMP-4 represents the primary endogenous ADAMTS7 inhibitor. In summary, our findings reveal LTBP4 as an ADAMTS7 substrate, whose cleavage may potentially impact elastogenesis in the cardiovascular system. We also identify TIMP-4 as a likely physiological ADAMTS7 inhibitor.

Chiara Pirillo, Flora Birch, Floriane S. Tissot, Sara Gonzalez Anton, Myriam Haltalli, Valentina Tini, Isabella Kong, Ben Partridge, Constandina Pospori, Karen Keeshan, Salvatore Santamaria, Edwin Hawkins, Brunangelo Falini, Andrea Marra, Delfim Duarte, Chiu Fan Lee, Edward Roberts, Cristina Lo Celso (2022)Metalloproteinase inhibition reduces AML growth, prevents stem cell loss, and improves chemotherapy effectiveness, In: Blood advances6(10)pp. 3126-3141 Elsevier

Acute myeloid leukemia (AML) is a blood cancer of the myeloid lineage. Its prognosis remains poor, highlighting the need for new therapeutic and precision medicine approaches. AML symptoms often include cytopenias linked to loss of healthy hematopoietic stem and progenitor cells (HSPCs). The mechanisms behind HSPC decline are complex and still poorly understood. Here, intravital microscopy (IVM) of a well-established experimental model of AML allows direct observation of the interactions between healthy and malignant cells in the bone marrow (BM), suggesting that physical dislodgment of healthy cells by AML through damaged vasculature may play an important role. Multiple matrix metalloproteinases (MMPs), known to remodel extracellular matrix, are expressed by AML cells and the BM microenvironment. We reason MMPs could be involved in cell displacement and vascular leakiness; therefore, we evaluate the therapeutic potential of MMP pharmacological inhibition using the broad-spectrum inhibitor prinomastat. IVM analyses of prinomastat-treated mice reveal reduced vascular permeability and healthy cell clusters in circulation and lower AML infiltration, proliferation, and cell migration. Furthermore, treated mice have increased retention of healthy HSPCs in the BM and increased survival following chemotherapy. Analysis of a human AML transcriptomic database reveals widespread MMP deregulation, and human AML cells show susceptibility to MMP inhibition. Overall, our results suggest that MMP inhibition could be a promising complementary therapy to reduce AML growth and limit HSPC loss and BM vascular damage caused by MLL-AF9 and possibly other AML subtypes.

Elisa Nuti, Francesca Casalini, Stanislava I. Avramova, Salvatore Santamaria, Marina Fabbi, Silvano Ferrini, Luciana Marinelli, Valeria La Pietra, Vittorio Limongelli, Ettore Novellino, Giovanni Cercignani, Elisabetta Orlandini, Susanna Nencetti, Armando Rossello (2010)Potent Arylsulfonamide Inhibitors of Tumor Necrosis Factor-alpha Converting Enzyme Able to Reduce Activated Leukocyte Cell Adhesion Molecule Shedding in Cancer Cell Models, In: Journal of medicinal chemistry53(6)pp. 2622-2635 Amer Chemical Soc

Activated leukocyte cell adhesion molecule (ALCAM) plays a relevant role in tumor biology and progression. Our previous studies showed that ALCAM is expressed at the surface of epithelial ovarian cancer (EOC) cells and is released in a soluble form by ADAM-17-mediated shedding. This process is relevant to EOC cell motility and invasiveness, which is reduced by nonspecific inhibitors of ADAM-17. For this reason. ADAM-17 may represent a new useful target in anticancer therapy. Herein, we report the synthesis and biological evaluation of new ADAM-17 inhibitors containing an arylsulfonamidic scaffold. Among the new potential inhibitors, two very promising compounds 17 and 18 were discovered, with a nanomolar activity for ADAM-17 isolated enzyme. These compounds proved to be also the most potent in inhibiting soluble ALCAM release in cancer cells, showing a nanomolar activity on A2774 and SKOV3 cell lines.

Salvatore Santamaria (2021)Targeting the PI3K/AKT pathway: a potential new weapon in the global fight against SARS-CoV-2?, In: International journal of biological sciences17(11)pp. 2770-2771 Ivyspring Int Publ

Commentary on 'Capivasertib restricts SARS-CoV-2 cellular entry: a potential clinical application for COVID-19' by Sun et al.

Elisa Nuti, Francesca Casalini, Stanislava I. Avramova, Salvatore Santamaria, Giovanni Cercignani, Luciana Marinelli, Valeria La Pietra, Ettore Novellino, Elisabetta Orlandini, Susanna Nencetti, Tiziano Tuccinardi, Adriano Martinelli, Ngee-Han Lim, Robert Visse, Hideaki Nagase, Armando Rossello (2009)N-O-Isopropyl Sulfonamido-Based Hydroxamates: Design, Synthesis and Biological Evaluation of Selective Matrix Metalloproteinase-13 Inhibitors as Potential Therapeutic Agents for Osteoarthritis, In: Journal of medicinal chemistry52(15)pp. 4757-4773 Amer Chemical Soc

Matrix metalloproteinase-13 (MMP-13) is a key enzyme implicated in the degradation of the extracellular matrix in osteoarthritis (OA). For this reason, MMP-13 synthetic inhibitors arc being sought as potential therapeutic agents to prevent cartilage degradation and to halt the progression of OA. Herein, we report the synthesis and in vitro evaluation of a new series of selective MMP-13 inhibitors possessing an arylsulfonamidic scaffold. Among these potential inhibitors, a very promising compound was discovered exhibiting nanomolar activity for MMP-13 and was highly selective for this enzyme compared to MMP-1, -14, and TACE. This compound acted as a slow-binding inhibitor of MMP-13 and was demonstrated to be effective in an in vitro Collagen assay and in a model of cartilage degradation. Furthermore, a docking study was conducted for this compound in order to investigate its binding interactions with MMP-13 and the reasons for its selectivity toward MMP-13 versus other MMPs.

Adrienn Teraz-Orosz, Magdalena Gierula, Anastasis Petri, David Jones, Renos Keniyopoullos, Patricia Badia Folgado, Salvatore Santamaria, James T B Crawley, David A Lane, Josefin Ahnström (2022)Laminin G1 residues of protein S mediate its TFPI cofactor function and are competitively regulated by C4BP, In: Blood advances6(2)pp. 704-715

Protein S is a cofactor in the tissue factor pathway inhibitor (TFPI) anticoagulant pathway. It enhances TFPIα-mediated inhibition of factor (F)Xa activity and generation. The enhancement is dependent on a TFPIα-protein S interaction involving TFPIα Kunitz 3 and protein S laminin G-type (LG)-1. C4b binding protein (C4BP), which binds to protein S LG1, almost completely abolishes its TFPI cofactor function. However, neither the amino acids involved in TFPIα enhancement nor the mechanisms underlying the reduced TFPI cofactor function of C4BP-bound protein S are known. To screen for functionally important regions within protein S LG1, we generated 7 variants with inserted N-linked glycosylation attachment sites. Protein S D253T and Q427N/K429T displayed severely reduced TFPI cofactor function while showing normal activated protein C (APC) cofactor function and C4BP binding. Based on these results, we designed 4 protein S variants in which 4 to 6 surface-exposed charged residues were substituted for alanine. One variant, protein S K255A/E257A/D287A/R410A/K423A/E424A, exhibited either abolished or severely reduced TFPI cofactor function in plasma and FXa inhibition assays, both in the presence or absence of FV-short, but retained normal APC cofactor function and high-affinity C4BP binding. The C4BP β-chain was expressed to determine the mechanisms behind the reduced TFPI cofactor function of C4BP-bound protein S. Like C4BP-bound protein S, C4BP β-chain-bound protein S had severely reduced TFPI cofactor function. These results show that protein S Lys255, Glu257, Asp287, Arg410, Lys423, and Glu424 are critical for protein S-mediated enhancement of TFPIα and that binding of the C4BP β-chain blocks this function.

Salvatore Santamaria, Elisa Nuti, Giovanni Cercignani, Luciana Marinelli, Valeria La Pietra, Ettore Novellino, Armando Rossello (2012)N-O-Isopropyl sulfonamido-based hydroxamates: Kinetic characterisation of a series of MMP-12/MMP-13 dual target inhibitors, In: Biochemical pharmacology84(6)pp. 813-820 Elsevier

Matrix metalloproteinases (MMPs) are a family of zinc dependent endopeptidases known to play key roles in extracellular matrix (ECM) breakdown disorders, such as the two main forms of arthritis, rheumatoid arthritis (RA) and osteoarthritis (OA). MMP-13 (collagenase 3) is the leading MMP involved in cartilage degradation through its particular ability to cleave type-II collagen and as such plays a pivotal role in the pathogenesis of these diseases. Here we report the kinetic characterisation of N-O-isopropyl sulfonamido-based hydroxamates, potent inhibitors of MMP-13 and MMP-12, bearing different P1 and P1' substituents. One of these compounds proved to be a potent (4

Salvatore Santamaria, Hideaki Nagase (2018)Measurement of Protease Activities Using Fluorogenic Substrates, In: S Cal, A J Obaya (eds.), Methods in molecular biology (Clifton, N.J.)pp. 107-122 Humana Press Inc

Matrix metalloproteinases and the related metalloproteases are implicated in cancer progression. They are endopeptidases that require several defined amino acid residues in both N-terminal and C-terminal sides of the scissile bond. Fluorogenic Forster resonance energy transfer (FRET) substrates that harbor a fluorophore and a quencher on opposite sides of the scissile bond are conveniently used to measure their activities. In this chapter, we describe the principle of FRET substrates and how to use them to measure activities and kinetic parameters of endopeptidases.

Kazuhiro Yamamoto, Carsten Scavenius, Maria M. Meschis, Abdulrahman M. E. Gremida, Emilie H. Mogensen, Ida B. Thogersen, Simone Bonelli, Simone D. Scilabra, Anders Jensen, Salvatore Santamaria, Josefin Ahnstrom, George Bou-Gharios, Jan J. Enghild, Hideaki Nagase (2022)A top-down approach to uncover the hidden ligandome of low-density lipoprotein receptor-related protein 1 in cartilage, In: Matrix biology112pp. 190-218 Elsevier

The low-density lipoprotein receptor-related protein 1 (LRP1) is a cell-surface receptor ubiquitously expressed in various tissues. It plays tissue-specific roles by mediating endocytosis of a diverse range of extracellular molecules. Dysregulation of LRP1 is involved in multiple conditions including osteoarthritis (OA) but little information is available about the specific profile of direct binding partners of LRP1 (ligandome) for each tissue, which would lead to a better understanding of its role in disease states. Here, we investigated adult articular cartilage where impaired LRP1-mediated endocytosis leads to tissue destruction. We used a top-down approach involving proteomic analysis of the LRP1 interactome in human chondrocytes, direct binding assays using purified LRP1 and ligand candidates, and validation in LRP1-deficient fibroblasts and human chondrocytes, as well as a novel Lrp1 conditional knockout (KO) mouse model. We found that inhibition of LRP1 and ligand interaction results in cell death, alteration of the entire secretome and transcriptional modulations in human chondrocytes. We identified a chondrocyte-specific LRP1 ligandome consisting of more than 50 novel ligand candidates. Surprisingly, 23 previously reported LRP1 ligands were not regulated by LRP1-mediated endocytosis in human chondrocytes. We confirmed direct LRP1 binding of HGFAC, HMGB1, HMGB2, CEMIP, SLIT2, ADAMTS1, TSG6, IGFBP7, SPARC and LIF, correlation between their affinity for LRP1 and the rate of endocytosis, and some of their intracellular localization. Moreover, a conditional LRP1 KO mouse model demonstrated a critical role of LRP1 in regulating the high-affinity ligands in cartilage in vivo. This systematic approach revealed the specificity and the extent of the chondrocyte LRP1 ligandome and identified potential novel therapeutic targets for OA. Crown Copyright (C) 2022 Published by Elsevier B.V.

Sergio M. Marques, Tiziano Tuccinardi, Elisa Nuti, Salvatore Santamaria, Vania Andre, Armando Rossello, Adriano Martinelli, M. Amelia Santos (2011)Novel 1-Hydroxypiperazine-2,6-diones as New Leads in the Inhibition of Metalloproteinases, In: Journal of medicinal chemistry54(24)pp. 8289-8298 Amer Chemical Soc

New compounds containing a novel zinc-binding group (1-hydroxypiperazine-2,6-dione, HPD) have been identified as effective inhibitors of matrix metalloproteinases (MMPs), with activities in the nanomolar concentration range. That moiety seemed to bind the catalytic zinc ion of MMPs, revealing itself as a new potential substitute for the hydroxamate group in the next generation of metalloproteinase inhibitors. The X-ray crystal structure of 1b elucidated its 3D conformation and supramolecular packing in solid state. Theoretical procedures were used to investigate the binding mode of this class of compounds, within the active site of MMP13. A computational method involving docking and hybrid quantum mechanical and molecular mechanical (QM/MM) dynamic simulations was developed and applied. This study suggested that the HPD moiety binds bidentately to the catalytic zinc through its oxygen atoms. The final structure obtained will allow straightforward drug design approaches in view of further optimization and development of new MMP inhibitors bearing the HPD moiety.

Magdalena Gierula, Isabelle I. Salles-Crawley, Salvatore Santamaria, Adrienn Teraz-Orosz, James T. B. Crawley, David A. Lane, Josefin Ahnstrom (2019)The roles of factor Va and protein S in formation of the activated protein C/protein S/factor Va inactivation complex, In: Journal of thrombosis and haemostasis17(12)pp. 2056-2068 Wiley

Background Activated protein C (APC)-mediated inactivation of factor (F)Va is greatly enhanced by protein S. For inactivation to occur, a trimolecular complex among FVa, APC, and protein S must form on the phospholipid membrane. However, direct demonstration of complex formation has proven elusive. Objectives To elucidate the nature of the phospholipid-dependent interactions among APC, protein S, and FVa. Methods We evaluated binding of active site blocked APC to phospholipid-coated magnetic beads in the presence and absence of protein S and/or FVa. The importance of protein S and FV residues were evaluated functionally. Results Activated protein C alone bound weakly to phospholipids. Protein S mildly enhanced APC binding to phospholipid surfaces, whereas FVa did not. However, FVa together with protein S enhanced APC binding (>14-fold), demonstrating formation of an APC/protein S/FVa complex. C4b binding protein-bound protein S failed to enhance APC binding, agreeing with its reduced APC cofactor function. Protein S variants (E36A and D95A) with reduced APC cofactor function exhibited essentially normal augmentation of APC binding to phospholipids, but diminished APC/protein S/FVa complex formation, suggesting involvement in interactions dependent upon FVa. Similarly, FVa(Nara) (W1920R), an APC-resistant FV variant, also did not efficiently incorporate into the trimolecular complex as efficiently as wild-type FVa. FVa inactivation assays suggested that the mutation impairs its affinity for phospholipid membranes and with protein S within the complex. Conclusions FVa plays a central role in the formation of its inactivation complex. Furthermore, membrane proximal interactions among FVa, APC, and protein S are essential for its cofactor function.

Kazuhiro Yamamoto, Salvatore Santamaria, Kenneth A Botkjaer, Jayesh Dudhia, Linda Troeberg, Yoshifumi Itoh, Gillian Murphy, Hideaki Nagase (2017)Inhibition of Shedding of Low-Density Lipoprotein Receptor-Related Protein 1 Reverses Cartilage Matrix Degradation in Osteoarthritis, In: Arthritis & rheumatology (Hoboken, N.J.)69(6)pp. 1246-1256

The aggrecanase ADAMTS-5 and the collagenase matrix metalloproteinase 13 (MMP-13) are constitutively secreted by chondrocytes in normal cartilage, but rapidly endocytosed via the cell surface endocytic receptor low-density lipoprotein receptor-related protein 1 (LRP-1) and subsequently degraded. This endocytic system is impaired in osteoarthritic (OA) cartilage due to increased ectodomain shedding of LRP-1. The aim of this study was to identify the LRP-1 sheddase(s) in human cartilage and to test whether inhibition of LRP-1 shedding prevents cartilage degradation in OA. Cell-associated LRP-1 and soluble LRP-1 (sLRP-1) released from human cartilage explants and chondrocytes were measured by Western blot analysis. LRP-1 sheddases were identified by proteinase inhibitor profiling and gene silencing with small interfering RNAs. Specific monoclonal antibodies were used to selectively inhibit the sheddases. Degradation of aggrecan and collagen in human OA cartilage was measured by Western blot analysis using an antibody against an aggrecan neoepitope and a hydroxyproline assay, respectively. Shedding of LRP-1 was increased in OA cartilage compared with normal tissue. Shed sLRP-1 bound to ADAMTS-5 and MMP-13 and prevented their endocytosis without interfering with their proteolytic activities. Two membrane-bound metalloproteinases, ADAM-17 and MMP-14, were identified as the LRP-1 sheddases in cartilage. Inhibition of their activities restored the endocytic capacity of chondrocytes and reduced degradation of aggrecan and collagen in OA cartilage. Shedding of LRP-1 is a key link to OA progression. Local inhibition of LRP-1 sheddase activities of ADAM-17 and MMP-14 is a unique way to reverse matrix degradation in OA cartilage and could be effective as a therapeutic approach.

Salvatore Santamaria, Kazuhiro Yamamoto (2020)Analysis of Aggrecanase Activity Using Neoepitope Antibodies, In: ADAMTS Proteasespp. 125-136 Springer New York

Aggrecan is a major matrix component of articular cartilage, and its dysregulated proteolysis is a crucial event in the pathogenesis of arthritis. Aggrecanases, members of ADAMTS family, play a pivotal role in aggrecan degradation with ADAMTS-4 and ADAMTS-5 being key enzymes. Cleavage events mediated by ADAMTSs are highly specific and very well characterized; therefore, it is possible to investigate aggrecanolysis by using antibodies reacting with the new N- and C-termini of the cleavage products (neoepitope antibodies). Here, we present a method for analyzing dynamic aggrecanolysis by Western blotting using neoepitope antibodies in combination with antibodies against total aggrecan fragments. The protocol is robust and has a broad application for investigation of aggrecanase activity in vitro and ex vivo.

Salvatore Santamaria (2020)ADAMTS-5: A difficult teenager turning 20, In: International journal of experimental pathology101(1-2)pp. 4-20 Wiley

A Disintegrin And Metalloproteinase with ThromboSpondin motif (ADAMTS)-5 was identified in 1999 as one of the enzymes responsible for cleaving aggrecan, the major proteoglycan in articular cartilage. Studies in vitro, ex vivo and in vivo have validated ADAMTS-5 as a target in osteoarthritis (OA), a disease characterized by extensive degradation of aggrecan. For this reason, it attracted the interest of many research groups aiming to develop a therapeutic treatment for OA patients. However, ADAMTS-5 proteoglycanase activity is not only involved in the dysregulated aggrecan proteolysis, which occurs in OA, but also in the physiological turnover of other related proteoglycans. In particular, versican, a major ADAMTS-5 substrate, plays an important structural role in heart and blood vessels and its proteolytic processing by ADAMTS-5 must be tightly regulated. On the occasion of the 20th anniversary of the discovery of ADAMTS-5, this review looks at the evidence for its detrimental role in OA, as well as its physiological turnover of cardiovascular proteoglycans. Moreover, the other potential functions of this enzyme are highlighted. Finally, challenges and emerging trends in ADAMTS-5 research are discussed.

Kazuhiro Yamamoto, Carsten Scavenius, Maria Meschis, Emilie Mogensen, Abdulrahman Gremida, Ida Thøgersen, Simone Bonelli, Simone Scilabra, Salvatore Santamaria, Josefin Ahnström, George Bou-Gharios, Jan Enghild, Hideaki Nagase Uncovering the ligandome of low-density lipoprotein receptor-related protein 1 in cartilage: a top-down approach to identify therapeutic targets, In: bioRxiv Cold Spring Harbor Laboratory Press

The low-density lipoprotein receptor-related protein 1 (LRP1) is a cell-surface receptor ubiquitously expressed in adult tissues. It plays tissue-specific physiological roles by mediating endocytosis of a diverse range of extracellular molecules. Dysregulation of LRP1 is involved in multiple conditions including Alzheimer′s disease, atherosclerosis and osteoarthritis (OA). However, little information is available about the specific ligand profile (ligandome) for each tissue, which would lead to better understanding of its role in disease states. Here, we investigated adult articular cartilage where impaired LRP1-mediated endocytosis leads to tissue destruction. We used a top-down approach involving analysis of human chondrocyte secretome, direct binding assays and validation in LRP1-deficient fibroblasts, as well as a novel Lrp1 conditional knockout (KO) mouse model. We found that inhibition of LRP1-mediated endocytosis results in cell death, alteration of the entire secretome and transcriptional modulations in human chondrocytes. We have identified more than 50 novel ligand candidates and confirmed direct LRP1 binding of HGFAC, HMGB1, HMGB2, CEMIP, SLIT2, ADAMTS1, IGFBP7, SPARC and LIF. Our in vitro endocytosis assay revealed the correlation of their affinity for LRP1 and the rate of endocytosis. Moreover, a conditional LRP1 KO mouse model demonstrated a critical role of LRP1 in regulating the high-affinity ligands in cartilage in vivo. This systematic approach revealed the extent of the chondrocyte LRP1 ligandome and identified potential novel therapeutic targets for OA. Competing Interest Statement The authors have declared no competing interest.

Salvatore Santamaria, Rens de Groot (2019)Monoclonal antibodies against metzincin targets, In: British journal of pharmacology176(1)pp. 52-66

The metzincin clan of metalloproteinases includes the MMP, disintegrin and metalloproteinase (ADAM) and ADAM with thrombospondin motifs families, which cleave extracellular targets in a wide range of (patho)physiological processes. Antibodies constitute a powerful tool to modulate the activity of these enzymes for both therapeutic and research purposes. In this review, we give an overview of monoclonal antibodies (mAbs) that have been tested in preclinical disease models, human trials and important studies of metzincin structure and function. Initial attempts to develop therapeutic small molecule inhibitors against MMPs were hampered by structural similarities between metzincin active sites and, consequently, off-target effects. Therefore, more recently, mAbs have been developed that do not bind to the active site but bind to surface-exposed loops that are poorly conserved in closely related family members. Inhibition of protease activity by these mAbs occurs through a variety of mechanisms, including (i) barring access to the active site, (ii) disruption of exosite binding, and (iii) prevention of protease activation. These different modes of inhibition are discussed in the context of the antibodies' potency, selectivity and, importantly, the effects in models of disease and clinical trials. In addition, various innovative strategies that were used to generate anti-metzincin mAbs are discussed. LINKED ARTICLES: This article is part of a themed section on Translating the Matrix. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.1/issuetoc.

Salvatore Santamaria, Frederic Buemi, Elisa Nuti, Doretta Cuffaro, Elena De Vita, Tiziano Tuccinardi, Armando Rossello, Steven Howell, Shahid Mehmood, Ambrosius P. Snijders, Rens de Groot (2021)Development of a fluorogenic ADAMTS-7 substrate, In: Journal of enzyme inhibition and medicinal chemistry36(1)pp. 2160-2169 Taylor & Francis

The extracellular protease ADAMTS-7 has been identified as a potential therapeutic target in atherosclerosis and associated diseases such as coronary artery disease (CAD). However, ADAMTS-7 inhibitors have not been reported so far. Screening of inhibitors has been hindered by the lack of a suitable peptide substrate and, consequently, a convenient activity assay. Here we describe the first fluorescence resonance energy transfer (FRET) substrate for ADAMTS-7, ATS7FP7. ATS7FP7 was used to measure inhibition constants for the endogenous ADAMTS-7 inhibitor, TIMP-4, as well as two hydroxamate-based zinc chelating inhibitors. These inhibition constants match well with IC 50 values obtained with our SDS-PAGE assay that uses the N-terminal fragment of latent TGF-β-binding protein 4 (LTBP4S-A) as a substrate. Our novel fluorogenic substrate ATS7FP7 is suitable for high throughput screening of ADAMTS-7 inhibitors, thus accelerating translational studies aiming at inhibition of ADAMTS-7 as a novel treatment for cardiovascular diseases such as atherosclerosis and CAD.

Kazuhiro Yamamoto, Hiroshi Okano, Wakako Miyagawa, Robert Visse, Yasuyuki Shitomi, Salvatore Santamaria, Jayesh Dudhia, Linda Troeberg, Dudley K. Strickland, Satoshi Hirohata, Hideaki Nagase (2016)MMP-13 is constitutively produced in human chondrocytes and co-endocytosed with ADAMTS-5 and TIMP-3 by the endocytic receptor LRP1, In: Matrix biology56pp. 57-73 Elsevier B.V

Matrix metalloproteinase 13 (MMP-13) degrades collagenous extracellular matrix and its aberrant activity associates with diseases such as arthritis, cancer, atherosclerosis and fibrosis. The wide range of MMP-13 proteolytic capacity suggests that it is a powerful, potentially destructive proteinase and thus it has been believed that MMP-13 is not produced in most adult human tissues in the steady state. Present study has revealed that human chondrocytes isolated from healthy adults constitutively express and secrete MMP-13, but that it is rapidly endocytosed and degraded by chondrocytes. Both pro- and activated MMP-13 bind to clusters II and III of low-density lipoprotein (LDL) receptor-related protein 1 (LRP1). Domain deletion studies indicated that the hemopexin domain is responsible for this interaction. Binding competition between MMP-13 and ADAMTS-4, -5 or TIMP-3, which also bind to cluster II, further shown that the MMP-13 binding site within cluster II is different from those of ADAMTS-4, -5 or TIMP-3. MMP-13 is therefore co-endocytosed with ADAMTS-5 and TIMP-3 by human chondrocytes. These findings indicate that MMP-13 may play a role on physiological turnover of cartilage extracellular matrix and that LRP1 is a key modulator of extracellular levels of MMP-13 and its internalization is independent of the levels of ADAMTS-4, -5 and TIMP-3. •ProMMP-13 is constitutively produced and endocytosed by chondrocytes.•LRP1 is a key modulator of extracellular levels of proMMP-13 and MMP-13.•ProMMP-13 and MMP-13 directly bind to LRP1 via the hemopexin domain.•Unique sites on LRP1 for MMP-13 binding have been mapped.•Co-endocytosis of proMMP-13 with ADAMTS-4, -5 and TIMP-3.

Salvatore Santamaria, Oleg Fedorov, John McCafferty, Gillian Murphy, Jayesh Dudhia, Hideaki Nagase, Kazuhiro Yamamoto (2017)Development of a monoclonal anti-ADAMTS-5 antibody that specifically blocks the interaction with LRP1, In: mAbs9(4)pp. 595-602 Taylor & Francis

The potent aggrecanase ADAMTS-5 is constitutively secreted by chondrocytes, but it is rapidly endocytosed in normal cartilage via the cell surface endocytic receptor LRP1. Therefore it is difficult to detect the total ADAMTS-5 activity produced. In this study, we isolated a monoclonal anti-ADAMTS-5 antibody 1B7 that blocks LRP1-mediated internalization without affecting the aggrecanolytic activity. Addition of 1B7 to cultured human chondrocytes revealed the full aggrecanolytic activity of ADAMTS-5 generated by the cells. 1B7 is a useful tool to estimate the ADAMTS-5 activity and to identify its potential roles in the tissues.

Elisa Nuti, Francesca Casalini, Salvatore Santamaria, Marina Fabbi, Grazia Carbotti, Silvano Ferrini, Luciana Marinelli, Valeria La Pietra, Ettore Novellino, Caterina Camodeca, Elisabetta Orlandini, Susanna Nencetti, Armando Rossello (2013)Selective Arylsulfonamide Inhibitors of ADAM-17: Hit Optimization and Activity in Ovarian Cancer Cell Models, In: Journal of medicinal chemistry56(20)pp. 8089-8103 Amer Chemical Soc

Activated leukocyte cell adhesion molecule (ALCAM) is expressed at the surface of epithelial ovarian cancer (EOC) cells and is released in a soluble form (sALCAM) by ADAM-17-mediated shedding. This process is relevant to EOC cell motility and invasiveness, which is reduced by inhibitors of ADAM-17. In addition, ADAM-17 plays a key role in EGFR signaling and thus may represent a useful target in anticancer therapy. Herein we report our hit optimization effort to identify potent and selective ADAM-17 inhibitors, starting with previously identified inhibitor 1. A new series of secondary sulfonamido-based hydroxamates was designed and synthesized. The biological activity of the newly synthesized compounds was tested in vitro on isolated enzymes and human EOC cell lines. The optimization process led to compound 21, which showed an IC50 of 1.9 nivi on ADAM-17 with greatly increased selectivity. This compound maintained good inhibitory properties on sALCAM shedding in several in vitro assays.

Salvatore Santamaria, Kazuhiro Yamamoto, Adrienn Teraz-Orosz, Christopher Koch, Suneel S. Apte, Rens de Groot, David A. Lane, Josefin Ahnstrom (2019)Exosites in Hypervariable Loops of ADAMTS Spacer Domains control Substrate Recognition and Proteolysis, In: Scientific reports9(1)pp. 10914-12 Springer Nature

ADAMTS (A Disintegrin-like and Metalloproteinase domain with Thrombospondin type 1 Motif)-1, -4 and -5 share the abilities to cleave large aggregating proteoglycans including versican and aggrecan. These activities are highly relevant to cardiovascular disease and osteoarthritis and during development. Here, using purified recombinant ADAMTS-1, -4 and -5, we quantify, compare, and define the molecular basis of their versicanase activity. A novel sandwich-ELISA detecting the major versican cleavage fragment was used to determine, for the first time, kinetic constants for versican proteolysis. ADAMTS-5 (k(cat)/K-m 35 x 10(5) M-1 s(-1)) is a more potent (similar to 18-fold) versicanase than ADAMTS-4 (k(cat)/K-m 1.86 x 10(5) M-1 sec(-1)), whereas ADAMTS-1 versicanase activity is comparatively low. Deletion of the spacer domain reduced versicanase activity of ADAMTS-5 19-fold and that of ADAMTS-4 167-fold. Co-deletion of the ADAMTS-5 cysteine-rich domain further reduced versicanase activity to a total 153-fold reduction. Substitution of two hypervariable loops in the spacer domain of ADAMTS-5 (residues 739-744 and 837-844) and ADAMTS-4 (residues 717-724 and 788-795) with those of ADAMTS-13, which does not cleave proteoglycans, caused spacer-dependent reductions in versicanase activities. Our results demonstrate that these loops contain exosites critical for interaction with and processing of versican. The hypervariable loops of ADAMTS-5 are shown to be important also for its aggrecanase activity. Together with previous work on ADAMTS-13 our results suggest that the spacer domain hypervariable loops may exercise significant control of ADAMTS proteolytic activity as a general principle. Identification of specific exosites also provides targets for selective inhibitors.

Kenneth A. Botkjaer, Hang Fai Kwok, Mikkel G. Terp, Aneesh Karatt-Vellatt, Salvatore Santamaria, John McCafferty, Peter A. Andreasen, Yoshifumi Itoh, Henrik J. Ditzel, Gillian Murphy (2016)Development of a specific affinity-matured exosite inhibitor to MT1-MMP that efficiently inhibits tumor cell invasion in vitro and metastasis in vivo, In: Oncotarget7(13)pp. 16773-16792 Impact Journals Llc

The membrane-associated matrix metalloproteinase-14, MT1-MMP, has been implicated in pericellular proteolysis with an important role in cellular invasion of collagenous tissues. It is substantially upregulated in various cancers and rheumatoid arthritis, and has been considered as a potential therapeutic target. Here, we report the identification of antibody fragments to MT1-MMP that potently and specifically inhibit its cell surface functions. Lead antibody clones displayed inhibitory activity towards pro-MMP-2 activation, collagen-film degradation and gelatin-film degradation, and were shown to bind to the MT1-MMP catalytic domain outside the active site cleft, inhibiting binding to triple helical collagen. Affinity maturation using CDR3 randomization created a second generation of antibody fragments with dissociation constants down to 0.11 nM, corresponding to an improved affinity of 332-fold with the ability to interfere with cell-surface MT1-MMP functions, displaying IC50 values down to 5 nM. Importantly, the new inhibitors were able to inhibit collagen invasion by tumor-cells in vitro and in vivo primary tumor growth and metastasis of MDA-MB-231 cells in a mouse orthotopic xenograft model. Herein is the first demonstration that an inhibitory antibody targeting sites outside the catalytic cleft of MT1-MMP can effectively abrogate its in vivo activity during tumorigenesis and metastasis.

Elisa Nuti, Laura Panelli, Francesca Casalini, Stanislava I. Avramova, Elisabetta Orlandini, Salvatore Santamaria, Susanna Nencetti, Tiziano Tuccinardi, Adriano Martinelli, Giovanni Cercignani, Nicola D'Amelio, Alessandro Maiocchi, Fulvio Uggeri, Armando Rossello (2009)Design, Synthesis, Biological Evaluation, and NMR Studies of a New Series of Arylsulfones As Selective and Potent Matrix Metalloproteinase-12 Inhibitors, In: Journal of medicinal chemistry52(20)pp. 6347-6361 Amer Chemical Soc

Overexpression of macrophage-elastase (MMP-12), a member of the matrix metalloproteinases family, can be linked to tissue remodeling and degradation in some inflammatory processes, such as chronic obstructive pulmonary disease (COPD), emphysema, rheumatoid arthritis (RA), and atherosclerosis. On this basis, MMP-12 can be considered an attractive target for studying selective inhibitors that are useful in the development of new therapies for COPD and other inflammatory diseases. We report herein the design, synthesis, and in vitro evaluation of a new series of compounds, possessing an arylsulfonyl scaffold, for their potential as selective inhibitors of MMP-12. The best compound in the series showed an IC50 value of 0.2 nM, with good selectivity over MMP-1 and MMP-14. A docking study was carried out on this compound in order to investigate its binding interactions with MMP-12, and NMR studies on the complex with the MMP-12 catalytic domain were able to validate the proposed binding mode.

Salvatore Santamaria, Natalia Reglinska-Matveyev, Magdalena Gierula, Rodney M. Camire, James T. B. Crawley, David A. Lane, Josefin Ahnstrom (2017)Factor V has an anticoagulant cofactor activity that targets the early phase of coagulation, In: The Journal of biological chemistry292(22)pp. 9335-9344 Amer Soc Biochemistry Molecular Biology Inc

Tissue factor pathway inhibitor (TFPI), the main inhibitor of initiation of coagulation, exerts an important anticoagulant role through the factor Xa (FXa)-dependent inhibition of tissue factor/ factor VIIa. Protein S is a TFPI cofactor, enhancing the efficiency of FXa inhibition. TFPI can also inhibit prothrombinase assembly by directly interacting with coagulation factor V (FV), which has been activated by FXa. Because full-length TFPI associates with FV in plasma, we hypothesized that FV may influence TFPI inhibitory function. Using pure component FXa inhibition assays, we found that although FV alone did not influence TFPI-mediated FXa inhibition, it further enhanced TFPI in the presence of protein S, resulting in an similar to 8-fold reduction in K-i compared with TFPI alone. A FV variant (R709Q/R1018Q/R1545Q, FV Delta IIa) that cannot be cleaved/activated by thrombin or FXa also enhanced TFPI-mediated inhibition of FXa similar to 12-fold in the presence of protein S. In contrast, neither activated FV nor recombinant B-domain-deleted FV could enhance TFPI-mediated inhibition of FXa in the presence of protein S, suggesting a functional contribution of the B domain. Using TFPI and protein S variants, we show further that the enhancement of TFPI-mediated FXa inhibition by protein S and FV depends on a direct protein S/TFPI interaction and that the TFPI C-terminal tail is not essential for this enhancement. In FXa-catalyzed prothrombin activation assays, both FV and FV IIa (but not activated FV) enhanced TFPI function in the presence of protein S. These results demonstrate a new anticoagulant (cofactor) function of FV that targets the early phase of coagulation before prothrombinase assembly.

Valeria La Pietra, Luciana Marinelli, Sandro Cosconati, Francesco Saverio Di Leva, Elisa Nuti, Salvatore Santamaria, Isabella Pugliesi, Matteo Morelli, Francesca Casalini, Armando Rossello, Concettina La Motta, Sabrina Taliani, Robert Visse, Hideaki Nagase, Federico da Settimo, Ettore Novellino (2012)Identification of novel molecular scaffolds for the design of MMP-13 inhibitors: A first round of lead optimization, In: European journal of medicinal chemistry47(1)pp. 143-152 Elsevier Masson SAS

Osteoarthritis (OA) is the leading cause of joint pain and disability in middle-aged and elderly patients, and is characterized by progressive loss of articular cartilage. Among the various matrix metalloproteinases (MMPs), MMP-13 is specifically expressed in the cartilage of human OA patients and is not present in normal adult cartilage. Thus, MMP-13-selective inhibitors are promising candidates in osteoarthritis therapy. Recently, we designed an N-isopropoxy-arylsulfonamide-based hydroxamate inhibitor, which showed low nanomolar activity and high selectivity for MMP-13. In parallel to further studies aiming to assess the in vivo activity of our compound, we screened the Life Chemicals database through computational docking to seek for novel scaffolds as zinc-chelating non-hydroxamate inhibitors. Experimental evaluation of 20 selected candidate compounds verified five novel leads with IC 50 in the low μM range. These newly discovered inhibitors are structurally unrelated to the ones known so far and provide useful scaffolds to develop compounds with more desirable properties. Finally, a first round of structure-based optimization on lead 1 was accomplished and led to an increase in potency of more than 5 fold. [Display omitted] ► Osteoarthritis (OA) is the leading cause of joint pain and disability in elderly patients. ► MMP-13-selective inhibitors are promising candidates in OA therapy. ► We screened the Life Chemicals database to seek for novel non-hydroxamate MMP-13 inhibitors. ► Experimental tests verified five novel leads. ► A first round of structure-based optimization on lead 1 was accomplished and led to an increase in potency of more than 5 fold.

Elisa Nuti, Doretta Cuffaro, Felicia D'Andrea, Lea Rosalia, Livia Tepshi, Marina Fabbi, Grazia Carbotti, Silvano Ferrini, Salvatore Santamaria, Caterina Camodeca, Lidia Ciccone, Elisabetta Orlandini, Susanna Nencetti, Enrico A Stura, Vincent Dive, Armando Rossello (2016)Sugar-Based Arylsulfonamide Carboxylates as Selective and Water-Soluble Matrix Metalloproteinase-12 Inhibitors, In: ChemMedChem11(15)pp. 1626-1637

Matrix metalloproteinase-12 (MMP-12) can be considered an attractive target to study selective inhibitors useful in the development of new therapies for lung and cardiovascular diseases. In this study, a new series of arylsulfonamide carboxylates, with increased hydrophilicity resulting from conjugation with a β-N-acetyl-d-glucosamine moiety, were designed and synthesized as MMP-12 selective inhibitors. Their inhibitory activity was evaluated on human MMPs by using the fluorimetric assay, and a crystallographic analysis was performed to characterize their binding mode. Among these glycoconjugates, a nanomolar MMP-12 inhibitor with improved water solubility, compound 3 [(R)-2-(N-(2-(3-(2-acetamido-2-deoxy-β-d-glucopyranosyl)thioureido)ethyl)biphenyl-4-ylsulfonamido)-3-methylbutanoic acid], was identified.

Elisa Nuti, Salvatore Santamaria, Francesca Casalini, Kazuhiro Yamamoto, Luciana Marinelli, Valeria La Pietra, Ettore Novellino, Elisabetta Orlandini, Susanna Nencetti, Anna Maria Marini, Silvia Salerno, Sabrina Taliani, Federico Da Settimo, Hideaki Nagase, Armando Rossello (2013)Arylsulfonamide inhibitors of aggrecanases as potential therapeutic agents for osteoarthritis: Synthesis and biological evaluation, In: European journal of medicinal chemistry62pp. 379-394 Elsevier

Aggrecanases, in particular aggrecanase-2 (ADAMTS-5), are considered the principal proteases responsible for aggrecan degradation in osteoarthritis. For this reason, considerable effort has been put on the discovery and development of aggrecanase inhibitors able to slow down or halt the progression of osteoarthritis. We report herein the synthesis and biological evaluation of a series of arylsulfonamido-based hydroxamates as aggrecanase inhibitors. Compound 18 was found to have a nanomolar activity for ADAMTS-5, ADAMTS-4 and MMP-13 and high selectivity over MMP-1 and MMP-14. Furthermore, this compound proved to be effective in blocking ex vivo cartilage degradation without having effect on cell cytotoxicity. (C) 2013 Elsevier Masson SAS. All rights reserved.

Salvatore Santamaria, Elisa Nuti, Giovanni Cercignani, Giuseppe La Regina, Romano Silvestri, Claudiu T. Supuran, Armando Rossello (2015)Kinetic characterization of 4,4 '-biphenylsulfonamides as selective non-zinc binding MMP inhibitors, In: Journal of enzyme inhibition and medicinal chemistry30(6)pp. 947-954 Taylor & Francis

We describe the characterisation of a series of 4,4'-biphenylsulfonamides as selective inhibitors of matrix metalloproteases MMP-2 and -13, two enzymes involved in cell invasion and angiogenesis. Double-inhibitor studies in the presence of acetohydroxamic acid show that these molecules do not bind the catalytic zinc. Moreover, two of the characterised inhibitors (11 and 19) act as non-competitive inhibitors, whereas the para-methyl ester derivative 13 behaves as a competitive inhibitor. This finding suggests that this class of molecules binds to a catalytic subsite, possibly the S1'-pocket. Moreover, since these compounds also act as inhibitors of carbonic anhydrases (CAs), another family of enzymes involved in cell invasion, they could be potentially useful as CA/MMP dual target inhibitors with increased efficacy as anticancer agents.