Glaucoma is a disease characterized by visual field loss as a result of the death of retinal ganglion cells. Although increased intraocular pressure remains the most clearly defined risk factor for glaucoma, it is becoming clear that a wide range of other factors can also lead to ganglion cell loss. Pharmacological or surgical regulation of intraocular pressure can stabilize many patients but for some there is still a progressive loss of vision. Thus, there is an urgent need to develop new rational strategies to slow or prevent neuronal loss occurring in glaucoma. There is abundant evidence that the eye, like other regions of the CNS, contains endogenous neurotrophic/neuroprotective factors that function to limit cell injury. It is the basic premise of this proposal that these neuroprotective mechanisms can be exploited to prevent much of the cell death associated with diseases such as glaucoma. This proposal focuses on one neuroprotective molecule, CNTF, a factor that has already been shown to have potent neuroprotective effects in a number of CNS regions including the retina and is a leading candidate for slowing the progression of ganglion cell loss. In our preliminary data we present evidence that CNTF supports the survival of purified rat RGCs in low density cultures and that its downstream effector STAT3 prevents RGCs from degenerating in ischemia- reperfusion injury. We now propose a series of experiments to test if RGCs can be prevented from dying in the presence of toxic levels of glutamate by CNTF. In a first aim we will define the pathways used by CNTF to exert its protective action. Second, we will examine whether M?ller glia can respond to CNTF and provide synergistic protection to RGCs by the secretion of additional neuroprotective factors or a range of other responses. Finally we will test whether the protective pathways activated by CNTF lead to a reduction in reactive oxygen species generation by mitochondria through the activation of mitochondrial uncoupling proteins.
Glaucoma is a blinding disease that affects over 65 million people worldwide. There is still not a good understanding of the basic biochemical mechanisms which cause the death of retinal cells and subsequent loss of vision. This research will identify some of these biochemical pathways. The results of this research will lead to the identification of target molecules for which new therapeutic drugs can be designed.
|Pinzon-Guzman, Carolina; Xing, Tiaosi; Zhang, Samuel Shao-Min et al. (2015) Regulation of rod photoreceptor differentiation by STAT3 is controlled by a tyrosine phosphatase. J Mol Neurosci 55:152-9|
|Li, Weiyi; Yang, Chen; Lu, Jing et al. (2014) Tetrandrine protects mouse retinal ganglion cells from ischemic injury. Drug Des Devel Ther 8:327-39|
|Huang, Ping; Huo, Yanjiao; Lou, Lucy X et al. (2013) CD4 positive T helper cells contribute to retinal ganglion cell death in mouse model of ischemia reperfusion injury. Exp Eye Res 115:131-9|
|Pinzon-Guzman, Carolina; Zhang, Samuel Shao-Min; Barnstable, Colin J (2011) Specific protein kinase C isoforms are required for rod photoreceptor differentiation. J Neurosci 31:18606-17|
|Li, Hong; Tran, Veronique V; Hu, Yueyue et al. (2006) A PEDF N-terminal peptide protects the retina from ischemic injury when delivered in PLGA nanospheres. Exp Eye Res 83:824-33|
|Tombran-Tink, Joyce; Aparicio, Samuel; Xu, Xuming et al. (2005) PEDF and the serpins: phylogeny, sequence conservation, and functional domains. J Struct Biol 151:130-50|
|Zhang, Samuel Shao-Min; Xu, Xuming; Li, Jinming et al. (2005) Comprehensive in silico functional specification of mouse retina transcripts. BMC Genomics 6:40|
|Zhang, Samuel Shao-Min; Liu, Mu-Gen; Kano, Arihiro et al. (2005) STAT3 activation in response to growth factors or cytokines participates in retina precursor proliferation. Exp Eye Res 81:103-15|
|Zhang, Samuel Shao-Min; Wei, Jiye; Qin, Hua et al. (2004) STAT3-mediated signaling in the determination of rod photoreceptor cell fate in mouse retina. Invest Ophthalmol Vis Sci 45:2407-12|
|Horvath, Tamas L; Diano, Sabrina; Barnstable, Colin (2003) Mitochondrial uncoupling protein 2 in the central nervous system: neuromodulator and neuroprotector. Biochem Pharmacol 65:1917-21|
Showing the most recent 10 out of 13 publications