Claire Mitchell



440 Levy Labs

3610 Hamilton Walk

Philadelphia, PA 19104

Research Description

The research of this laboratory is concerned with the ability of purinergic and glutaminergic neurotransmitter systems to modify ocular health. These neurotransmitters were among the first to develop evolutionarily and can be released from non-specialized cell types such as epithelial and glial cells in additional to neurons. Research is presently focused upon how these neurotransmitters alter the function of retinal pigment epithelial cells in the outer retina, and how they affect retinal ganglion cell viability under glaucomatous conditions.

The retinal pigment epithelium supports the function of the photoreceptor outer segments and we believe the purines ATP and adenosine, along with glutamate, can modify their interaction. The retinal pigment epithelium can release ATP into the subretinal space separating the two cell types, and the laboratory is currently investigating how this released ATP is converted into adenosine by ecto-enzymes, and how the adenosine thus produced can modulate RPE physiology. We are particularly interested in the pathways for ATP release and the regulation of ecto-enzyme activity. This information may enhance our understanding of the communication between the RPE and photoreceptors under physiologic and pathophysiologic conditions.

Purines and glutamate are also critical for the health of retinal ganglion cells. The ganglion cells convey the visual message from the eye to the brain, and are the primary cell lost after the elevations of intraocular pressure common in glaucoma. Currently, the lab is investigating whether elevations of ATP follow the increase in intraocular pressure found in glaucoma, and the role of P2X7 receptors for ATP in ganglion cell death. The cellular mechanisms which link P2X7 stimulation to cell death may differ in neurons and are being investigated. The neuroprotective potential of P2X7 antagonists, and of adenosine agonists are being examined. We are also concerned with the contribution of glutamate in this process, and whether its role is a primary or secondary in response to changes in ATP levels.

Degrees & Education

BSc, McGill University, 1986

PhD, Institute of Ophthalmology, University College London, 1994

Honors & Awards

1988 Fight for Sight UK Studentship Award

1992 Royal National Institute for the Blind Fellowship

1994 International Society of Eye Research Award

1995 NRSA Fellowship in Neuroscience

1996 NRSA Fellowship in Respiratory Physiology

2002 University Research Foundation Award

Professional Affiliations

American Physiological Society

Association for Research in Vision and Ophthalmology

Salt and Water Club

Recent Publications
September 20, 2021
Rapid morphologic changes to microglial cells and upregulation of mixed microglial activation state markers induced by P2X7 receptor stimulation and increased intraocular pressure
Claire Mitchell, Ph.D.
Campagno KE, Lu W, Jassim AH, Albalawi F, Cenaj A, Tso HY, Clark SP, Sripinun P, Gómez NM, Mitchell CH - doi: 10.1186/s12974-021-02251-7
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July 21, 2021
Crosstalk Between Dysfunctional Mitochondria and Inflammation in Glaucomatous Neurodegeneration
Claire Mitchell, Ph.D.
Jassim AH, Inman DM, Mitchell CH - doi: 10.3389/fphar.2021.699623
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February 17, 2020
Evoked and spontaneous pain assessment during tooth pulp injury
Claire Mitchell, Ph.D.
Heather Lynn Rossi, Lily Pachanin See, William Foster, Saumitra Pitake, Jennifer Gibbs, Brian Schmidt, Claire H. Mitchell & Ishmail Abdus-Saboor - DOI:10.1038/s41598-020-59742-5
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March 15, 2021
TheP2X7 Receptor in Microglial Cells Modulates the Endolysosomal Axis, Autophagy, and Phagocytosis
Claire Mitchell, Ph.D.
Campagno, K. E. & Mitchell, C. H - DOI: 10.3389/fncel.2021.645244
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November 24, 2020
Polarized Cytokine Release Triggered by P2X7 Receptor from Retinal Pigmented Epithelial Cells Dependent on Calcium Influx
Claire Mitchell, Ph.D.
Xiaolei Shao, Sonia Guha, Wennan Lu, Keith E Campagno, Jonathan M Beckel, Jason A Mills, Wenli Yang, Claire H Mitchell - DOI: 10.3390/cells9122537
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