| Summary: | 碩士 === 國立陽明大學 === 藥理學研究所 === 105 === Glaucoma is one kind of retinal diseases. The main symptoms are severe atrophic optic nerves and irreversible progressive loss of retinal ganglion cells (RGCs). Many factors may induce the occurrence of Glaucoma, including genes, ocular fluid accumulation or external squeeze pull and other factors, while elevated intraocular pressure (IOP) is the major risk factor for glaucoma. So far, most of studies were focused on the influence of IOP on trabecular meshwork but not RGCs, whereas accompanied dystrophy of RGCs would lead to progressive visual loss very quickly. Hence, it is needed to develop combinative therapeutics for retarding the deleterious of RGCs. In the past, many studied showed that pathogenesis of glaucoma was accompanied with high osmotic pressure, which disturbed the cellular adhesion and calcium balance by increasing the expression of glaucoma relative genes, such as CYP1B1. However, fewer studies mentioned the effects of the alteration of osmolarity on RGCs. Therefore, this study intends to through administrating the hiPSCs derived retinal ganglion cells with high osmotic pressure to explore and accomplish the following three goals: (1) To validate the effect of osmotic pressure influences on the genetic expression, i.e. glaucoma related genes and the physiological function of RGCs, including electrophysiological manifestations and neural growth factors secretion. (2) To detect the responses of pressure-related molecules, i.e. ion channel TRPV1 or TRPV4 and their downstream protein expression which is corresponding to the function and morphological regulation of RGCs. (3) To reduce the activation of pressure-stimulated molecules by applying RGCs with the channel or receptor blockers, or its downstream inhibitors, activators for further validating the essential role of our targeted pressure-relative molecules in mediating cellular fluid/transmission and the secretion of neural growth factors, i.e. BDNF. Meanwhile, via the inhibition of the targeted pressure-related molecules, it will be benefit to recover the functions and morphology of RGCs under osmolarity stimulation. Furthermore, our study reveals that TRPV1 expression is the key player in maintaining the early survival of high osmolality-induced damaged hiPSC-derived RGCs and a downstream member of activated TRPV1 functions to protect RGC cells from injuries by promoting the immediate generation of BDNF. Meanwhile, TRPV1 also enhanced the influx of calcium followed by the activation of a cascade of autophagy molecules. I-RTX and H89 demonstrated that the translocation of TRPV1 from ER to cell membrane is essential for cell survival, and the overexpression of TRPV1 would lead to ultimate cell death. This study is expected to provide new options for future development of glaucoma treatment.
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