Professor Stewart Sage

College positions: Director of Studies in Medical Sciences (Part IA)

University position: Professor in Cell Physiology

Subject: Medical Sciences; Physiology

Professor Stewart Sage is Professor of Cell Physiology and Director of Studies in Medical Sciences at Magdalene.

Professor Stewart Sage's research focuses on intracellular calcium signalling mechanisms and the roles of calcium signals in platelet function. A significant part of this work examines the processes that generate calcium entry, particularly the mechanisms that link the depletion of intracellular calcium stores to the activation of calcium entry. This research employs fluorescent indicators and protein chemistry.

Most recently, in collaboration with Dr Alan Harper (a former Research Fellow in Professor Sage's lab and now based at the Institute for Science and Technology in Medicine, Keele University), the research has explored platelet calcium signalling at a systems level. This involves investigating agonist-evoked changes in the concentration of calcium and other ions that influence calcium movements in various cellular and pericellular compartments. The findings have identified a calcium recycling system in platelets, which appears to involve nanojunctions between the dense tubular system and the open canalicular system at the platelet membrane complex.

KEY PUBLICATIONS

The TRPV1 ion channel is expressed in human but not mouse platelets. Platelets, vol. 25 (2014), pp. 390–392, with S.O. Sage, G.E. Jarvis, I. Jardín, J.A. Rosado and A.G.S. Harper.

Pericellular Ca2+ recycling potentiates thrombin-evoked Ca2+ signals in human platelets. Physiological Reports, vol. 1 (2013), e00085, with S.O. Sage, N. Pugh, R.F. Farndale and A.G.S. Harper.

Monitoring the intracellular store Ca2+ concentration in agonist-stimulated, intact human platelets using Fluo-5N. Journal of Thrombosis and Haemostasis, vol. 9 (2011), pp. 540–551, with S.O. Sage, N. Pugh, M.J. Mason and A.G.S. Harper.

Phorbol ester-evoked Ca2+ signaling in human platelets is via autocrine activation of P receptors, not a novel non-capacitative Ca2+ entry. Journal of Thrombosis and Haemostasis, vol. 8 (2010), pp. 1604–1613, with M.T. Harper, M.J. Mason, S.O. Sage and A.G.S. Harper.

Src family tyrosine kinases activate thrombin-induced non-capacitative cation entry in human platelets. Platelets, vol. 21 (2010), pp. 445–450, with M.T. Harper and S.O. Sage.

A role for TRPV1 in agonist-evoked activation of human platelets. Journal of Thrombosis and Haemostasis, vol. 7 (2009), pp. 330–339, with A.G.S. Harper, S.L. Brownlow and S.O. Sage.

A key role for dense granule secretion in potentiation of the Ca2+ signal arising from store-operated calcium entry in human platelets. Cell Calcium, vol. 45 (2009), pp. 413–420, with A.G.S. Harper, M.J. Mason and S.O. Sage.

Non-redundant roles of phosphoinositide 3-kinase isoforms alpha and beta in glycoprotein VI-induced platelet signaling and thrombus formation. Journal of Biological Chemistry, vol. 284 (2009), pp. 33750–33762, with K. Gilio, I.C. Munnix, P. Mangin, J.M. Cosemans, M.A. Feijge, P.E. van der Meijden, M.B. Chrzanowska-Wodnicka, L. Lillian, S. Schoenwaelder, S. Koyasu, S.O. Sage, S.P. Jackson and J.W.M. Heemskerk.

Is calcium-independent phospholipase A2 required for store-operated calcium entry in human platelets? Journal of Thrombosis and Haemostasis, vol. 6 (2008), pp. 1819–1821, with M.T. Harper and S.O. Sage.

A role for the intracellular protease calpain in the activation of store-operated calcium entry in human platelets. Cell Calcium, vol. 41 (2007), pp. 169–178, with A.G.S. Harper and S.O. Sage.

A key role for reverse Na+/Ca2+ exchange influenced by the actin cytoskeleton in store-operated Ca2+ entry in human platelets: Evidence against the de novo conformational coupling hypothesis. Cell Calcium, vol. 42 (2007), pp. 606–617, with A.G.S. Harper and S.O. Sage.

A role for cofilin in the activation of store-operated calcium entry by de novo conformational coupling in human platelets. Blood, vol. 107 (2006), pp. 973–979, with P.C. Redondo, M.T. Harper, J.A. Rosado and S.O. Sage.

Email
sos10@cam.ac.uk

Call
01223 333870