Dr Isabel Orriss

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Dr Isabel Orriss

Isabel Orriss in an Arthritis Research UK funded Career Development Fellow based in the Bone Biology Laboratory at UCL. She is a committee member of the Bone Research Society, having previously served as the society’s young investigator representative. She is on the editorial board of Frontiers in Bone Research and belongs to a number of international societies including the European Calcified Tissue Society and the American Society for Bone and Mineral Research. She runs the departmental microCT unit which is located in the Bone Biology Laboratory.


Tel: +44 (0) 20 7679 3487


Bone growth and turnover result from the co-ordinated activities of osteoblasts (bone forming cells) and osteoclasts (bone destroying cells). Imbalance in the activities of these cells can lead to the common bone loss disorder osteoporosis.

I am interested in how extracellular nucleotides, such as ATP and UTP, regulate osteoclast and osteoblast function. I am currently developing new lines of research into the roles of extracellular nucleotides in vascular calcification and bone cancer.

Key findings that this research has identified to date include:

1) Bone cells express multiple P2 receptors in a cellular differentiation-dependent manner.

2) ATP, UTP and the hydrolysis product, pyrophosphate, play a central role in the regulation of bone mineralization.

3) P2 receptor knockout mice (P2Y1, P2Y2 and P2Y6 receptors) display significant changes in bone structure and mass.

4) Activation of the P2Y6 receptor by its agonist, UDP, stimulates the formation and resorptive activity of osteoclasts.

5) Clopidogrel, a P2Y12 receptor antagonist and drug widely used to treat heart disease and stroke, inhibits bone cell function in vitro and decreases trabecular bone in vivo.

Other lab members: Tim Arnett (Professor of Mineralised Tissue Biology), Mark Hajjawi (PhD student), Stéphanie Gohin (Post-doctoral Fellow), Michelle Key (Hon Postdoctoral Fellow), Daniel Wornham (MBBS research project student).


Arthritis Research UK


2001 BSc Biochemistry, University of Southampton

2005 PhD Cell and Molecular Biology, University College London

2005 Postdoctoral associate, University College London

2008 Senior postdoctoral associate, University College London

2010 Career Development Fellow, University College London

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Orriss IR, Arnett TR (2012) P2Y receptors in bone. WIREs Membr Transp Signal (in press)

Syberg S, Brandao-Burch A, Patel JJ, Hajjawi M, Arnett TR, Schwarz P, Jorgensen NR, Orriss IR (2012). Clopidogrel (Plavix®), a P2Y12 receptor antagonist, inhibits bone cell function in vitro and decreases trabecular bone in vivo. J Bone Mineral Res [epub ahead of print].

Patel JJ, Utting JC, Key ML, Orriss IR, Taylor SEB, Whatling P, Arnett TR (2012). Hypothermia inhibits osteoblast differentiation and bone formation but stimulates osteoclastogenesis. Exp Cell Res 318:2237-2244

Orriss IR, Key ML, Brandao-Burch A, Patel JJ, Burnstock G, Arnett TR (2012). The regulation of osteoblast function and bone mineralization by extracellular nucleotides: the role of P2X receptors. Bone 51:389-400

Brandao-Burch A, Key ML, Patel JJ, Arnett TR, Orriss IR (2012). The P2X7 receptor is an important regulator of extracellular ATP levels. Front Endocrin 3:41.

Cesca F, Yabe A, Specer-Dene B, Scholz-Starke J, Orriss IR, Baldelli P, Al-Qatari M, Adams RH, Benfanati F, Schiavo G (2012). Kidins220/ARMS mediates neurotrophin signalling in central and peripheral nervous system development. Cell Death Differ 1912:194-208.

Gartland A, Orriss IR, Rumney RMH, Bond AP, Arnett TR, Gallagher JA (2012). Purinergic signalling in osteoblasts. Front Biosci 17:16-29.

Orriss IR, Taylor SEB, Arnett TR (2012). Rat osteoblast cultures. Methods Mol Biol 816:31-41.

Orriss IR, Arnett TR (2012). Rodent osteoclast cultures. Methods Mol Biol 816:103-117.


Orriss IR, Wang N, Burnstock G, Arnett TR, Gartland A, Robaye B, Boeynaems JM (2011). The P2Y6 receptor stimulates bone resorption by osteoclasts. Endocrinology 152:3706-3716.

Orriss IR, Syberg S, Wang N, Robaye B, Gartland A, Jorgensen N, Arnett TR, Boeynaems JM (2011). Bone phenotypes displayed by P2 receptor knockout mice. Front Biosci S3:1038-1046.


Utting JC, Flanagan AM, Massey HM, Brandao-Burch A, Orriss IR, Arnett TR (2010). Hypoxia stimulates osteoclast formation from human peripheral blood. Cell Biochem Funct 28:374-380.

Orriss IR, Burnstock G, Arnett TR (2010). Purinergic signalling and bone remodeling. Curr Opin Pharmacol 10:322-330.


Orriss IR, Knight GE, Utting JC, Taylor SEB, Burnstock G, Arnett TR (2009). ATP release from rat osteoblasts is enhanced by hypoxia J Cell Physiol 220:155-162.

Orriss IR, Key ML, Colston K, Arnett TR (2009). Inhibition of osteoblast function in vitro by aminobisphosphonates J Cell Biochem 106:109-18.

Orriss IR, Utting JC, Brandao-Burch A, Colston K, Grubb BR, Burnstock G, Arnett TR (2007). Extracellular nucleotides block bone mineralisation in vitro: evidence for dual inhibitory mechanisms involving both P2Y2 receptors and pyrophosphate. Endocrinology 148:4208-4216.

Orriss IR, Knight GE, Ranasinghe S, Burnstock G, Arnett TR (2006) Osteoblast responses to nucleotides increase during differentiation. Bone 39:300-309.

Utting JC, Robins SP, Brandao-Burch A, Orriss IR, Behar J, Arnett TR (2006). Hypoxia inhibits growth, differentiation and bone-forming capacity of rat osteoblasts. Exp Cell Res. 312: 1693-1672.

Brandao-Burch A, Utting J, Orriss IR, Arnett TR (2005). Acidosis inhibits bone formation by osteoblasts in vitro by preventing mineralisation. Calcif Tissue Int. 77: 163-174.

Arnett TR, Gibbons DC, Utting JC, Orriss IR, Hoebertz A, Rosendaal M, Megjhi S (2003). Hypoxia is a major stimulator of osteoclast formation and bone resorption. J Cell Physiol. 196:2-8.

Micro CT image

UCL microCT platform

This facility is located within the Bone Biology Laboratory at UCL and comprises of a SkyScan 1172 microCT scanner (www.skyscan.be). This system can be used to scan a variety of tissues at micron resolution and is available to other researchers to use. For further information, please contact Isabel Orriss (i.orriss@ucl.ac.uk).

Page last modified on 09 nov 12 11:21