Dr Salvatore Santamaria
ResearchResearch interests
Dr Salvatore Santamaria is a British Heart Foundation Basic Science Research Fellow and a Lecturer in Cardiovascular Science in the Department of Biochemical Sciences.
He obtained an MSc in Biotechnology from University of Pisa, Italy, in September 2008. He worked for one year as a Research Assistant in Prof. Armando Rossello’s laboratory, University of Pisa, where he characterised small molecule inhibitors of matrix metalloproteases. In October 2009 he joined Prof. Hideaki Nagase’s laboratory at Imperial College London where he isolated and characterised inhibitory antibodies of ADAMTS5, a key protease in osteoarthritis. A substantial part of his PhD was spent in his co-supervisor Prof. Gillian Murphy’s laboratory (Cancer Research Institute, Cambridge) and in Dr John McCafferty’s laboratory (Biochemistry Department, University of Cambridge, and now Iontas Ltd). During this time he matured his knowledge of phage display and in vitro selection methods. He was awarded his PhD in 2014. From 2013 till 2015 he worked at the University of Oxford, first as a Research Assistant, then as a Post-Doc. During this period he investigated the effect of anti-ADAMTS-5 antibodies in cell-based and ex-vivo models of osteoarthritis. He joined the Centre for Haematology at Imperial College in February 2015 as a Post-Doctoral Researcher in Dr. Josefin Ahnström's lab where he investigated the anticoagulant function of factor V. In 2019, he was awarded the Young Investigator Award from the British Society for Matrix Biology in 2019 for his contributions to the field and in 2021 a BHF Basic Science Intermediate Fellowship.
In 2022 he moved to the University of Surrey. He has published 30 peer-reviewed papers, 5 reviews and 4 book chapters. So far, he has secured funding for around £1.2 million.
The Santamaria lab is interested in the turnover of large chondroitin sulfate proteoglycans by ADAMTSs proteases and its relevance for diseases such as thoracic aortic aneurysms, pulmonary arterial hypertension and osteoarthritis. They study this from a mechanistic perspective using a variety of techniques ranging from direct binding assays, enzyme kinetics and proteomics.
Research interests
Dr Salvatore Santamaria is a British Heart Foundation Basic Science Research Fellow and a Lecturer in Cardiovascular Science in the Department of Biochemical Sciences.
He obtained an MSc in Biotechnology from University of Pisa, Italy, in September 2008. He worked for one year as a Research Assistant in Prof. Armando Rossello’s laboratory, University of Pisa, where he characterised small molecule inhibitors of matrix metalloproteases. In October 2009 he joined Prof. Hideaki Nagase’s laboratory at Imperial College London where he isolated and characterised inhibitory antibodies of ADAMTS5, a key protease in osteoarthritis. A substantial part of his PhD was spent in his co-supervisor Prof. Gillian Murphy’s laboratory (Cancer Research Institute, Cambridge) and in Dr John McCafferty’s laboratory (Biochemistry Department, University of Cambridge, and now Iontas Ltd). During this time he matured his knowledge of phage display and in vitro selection methods. He was awarded his PhD in 2014. From 2013 till 2015 he worked at the University of Oxford, first as a Research Assistant, then as a Post-Doc. During this period he investigated the effect of anti-ADAMTS-5 antibodies in cell-based and ex-vivo models of osteoarthritis. He joined the Centre for Haematology at Imperial College in February 2015 as a Post-Doctoral Researcher in Dr. Josefin Ahnström's lab where he investigated the anticoagulant function of factor V. In 2019, he was awarded the Young Investigator Award from the British Society for Matrix Biology in 2019 for his contributions to the field and in 2021 a BHF Basic Science Intermediate Fellowship.
In 2022 he moved to the University of Surrey. He has published 30 peer-reviewed papers, 5 reviews and 4 book chapters. So far, he has secured funding for around £1.2 million.
The Santamaria lab is interested in the turnover of large chondroitin sulfate proteoglycans by ADAMTSs proteases and its relevance for diseases such as thoracic aortic aneurysms, pulmonary arterial hypertension and osteoarthritis. They study this from a mechanistic perspective using a variety of techniques ranging from direct binding assays, enzyme kinetics and proteomics.
Publications
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.
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.
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.