Background Glaucoma can cause progressive damage to retinal ganglion cells. These cells can be classified as cells projecting to the superior colliculus and melanopsin-containing retinal ganglion cells, which project ...Background Glaucoma can cause progressive damage to retinal ganglion cells. These cells can be classified as cells projecting to the superior colliculus and melanopsin-containing retinal ganglion cells, which project to the suprachiasmatic nucleus. This study was to investigate the effects of chronic intraocular pressure elevation on melanopsin-containing retinal ganglion cells in rats. Methods Chronic intraocular pressure elevation was induced in one eye of adult Wistar rats by cauterization of three episcleral veins. Intraocular pressure was measured at different intervals with a rebound tonometer. Superior collicular retinal ganglion cells were retrogradely labeled from the superior colliculus with Fluorogold. Melanopsin-containing retinal ganglion cells were visualized by free-floating immunohistochemistry on whole-mount retinas. The number of labeled superior collicular and melanopsin-containing retinal ganglion cells were counted in the sample areas on flat-mounted retinas. Results Compared with contralateral control eyes, the numbers of both superior collicular and melanopsin-containing retinal ganglion cells were significantly reduced after 12 weeks of experimental intraocular pressure elevation （（2317.41±29.96）/mm^2 vs （1815.82±24.25）/mm^2; （26.20±2.10）/mm^2 vs （20.62±1.52）/mm^2, respectively）. The extent of cell loss of the two types of retinal ganglion cells was similar. However, no morphologic changes were found in melanopsin-containing retinal ganglion cells. Conclusion Both melanopsin-containing and superior collicular retinal ganglion cells were damaged by chronic ocular hypertension, indicating that glaucomatous neural degeneration involves the non-image-forming visual pathway.展开更多
Background Latanoprost, a prostaglandin F2α analog, has been shown to be an effective intraocular pressure lowering agent which acts by inducing ciliary muscle cells to synthesise matrix metalloproteinases. However, ...Background Latanoprost, a prostaglandin F2α analog, has been shown to be an effective intraocular pressure lowering agent which acts by inducing ciliary muscle cells to synthesise matrix metalloproteinases. However, the response of ciliary melanocytes to latanoprost has never been reported. This research has investigated the ability of latanoprost to induce matrix metalloproteinase-1 expression in human ciliary melanocytes, and thereby advance the understanding of the mechanism of PGF2α in decreasing intraocular pressure. Methods In vitro human ciliary melanocytes were treated for 48 hours with five different concentrations of latanoprost （100, 150, 200, 500, and 1000 nmol/L）. Ciliary melanocytes treated with 0.01% ethanol （vehicle） were used as a control. The expression of matrix metalloproteinase-1 in ciliary melanocytes was determined by Western blotting and immunofluorescent staining. Results Western blotting showed that the expression of matrix metalloproteinase-1 in ciliary melanocytes was induced by latanoprost, and the level of expression was dependent on the concentration of latanoprost in the culture medium. Immunofluorescent staining showed that matrix metalloproteinase-1 was confined to the ciliary melanocyte cytoplasm. Conclusions Latanoprost induced the expression of matrix metalloproteinase-1 in human ciliary melanocytes in a dose-dependent manner. Ciliary melanocytes, as well as ciliary muscle cells, may also play an important role in uveoscleral outflow modulation.展开更多
Choroidal neovascularization （CNV）, a major cause of vision loss, is the result of the increased vascular endothelial growth factor （VEGF） expression in human retinal pigment epithelial （RPE） cells. It is import...Choroidal neovascularization （CNV）, a major cause of vision loss, is the result of the increased vascular endothelial growth factor （VEGF） expression in human retinal pigment epithelial （RPE） cells. It is important to inhibit the expression of VEGF protein in RPE cells.展开更多
Background Proneurotrophins such as the precursor of nerve growth factor （proNGF） and the precursor of brain-derived neurotrophic factor （proBDNF） interacted with sortilin and p75NTR to form a complex capable of a...Background Proneurotrophins such as the precursor of nerve growth factor （proNGF） and the precursor of brain-derived neurotrophic factor （proBDNF） interacted with sortilin and p75NTR to form a complex capable of activating an apoptotic signaling. We found that the expression of p75NTR and sortilin was increased in ischemic retina induced by elevated intraocular pressure （lOP）, but the protein expression changes of proNGF and proBDNF in the same situation were not clear. This study aimed to ascertain the protein expression changes of proNGF and proBDNF in ischemic retina induced by elevated lOP.展开更多
Background Studies indicated that Mer might be the main contributor to the specific internalization of photoreceptor outer segments （POS） in retinal pigment epithelium （RPE）. It is very important to understand the...Background Studies indicated that Mer might be the main contributor to the specific internalization of photoreceptor outer segments （POS） in retinal pigment epithelium （RPE）. It is very important to understand the mechanism of POS phagocytosis under the pathway of Mer and its ligands. The objective of this study was to identify changes in gene expression profiles caused by Mergene knockout （Mer-/-） during phagocytosis of POS in RPE. Methods RPE from both Mer-/- and wild-type （WT） mice were isolated and cultured to the 3rd passage. POS were subjected to culture medium with 20 nmol/L Gas6 and protein S to activate specific mer-mediated phagocytosis. RPE phagocytosis was evaluated by phagocytosis assays and differential gene expression identified by microarray at 3 and 12 hours; the 0-hour time point served as the control. Three independent samples for each Mer-/- or WT RPE were subjected to the same protocol of microarray. Five genes were confirmed by real-time quantitative PCR （QPCR）. Results The Mer-/- RPE had less internalized POS than WT RPE after both 3 and 12 hours in phagocytosis assay. Compared to WT RPE and the 0-hour control, 38 and 45 different known genes were increased and 68 and 59 known genes were decreased in Mer-/- RPE after 3 and 12 hours, respectively. Abnormal POS phagocytosis in Mer-/- RPE was associated with significant gene expression changes in, for example, signal transduction （WNT, MAPK）, phagocytosis （Vav3, Hsdllb1）, cytoskeleton components （Myo7a）, and metabolism, in a time-specific manner. QPCR results showed Vav3, Hsdllb1, Myo7a, Rtn2 and Itga8 in those independent samples were consistent with microarray. Conclusion Gene expression profiles modulated in a time-specific manner in Mer-/- RPE indicate a possible internalization mechanism for abnormal POS phagocytosis, which gives insight into the mechanism of retinitis pigmentosa caused by the mutation of MerTK in humans.展开更多
基金This study was supported by a grant from the National Natural Science Foundation of China （No. 30571991）.
文摘Background Glaucoma can cause progressive damage to retinal ganglion cells. These cells can be classified as cells projecting to the superior colliculus and melanopsin-containing retinal ganglion cells, which project to the suprachiasmatic nucleus. This study was to investigate the effects of chronic intraocular pressure elevation on melanopsin-containing retinal ganglion cells in rats. Methods Chronic intraocular pressure elevation was induced in one eye of adult Wistar rats by cauterization of three episcleral veins. Intraocular pressure was measured at different intervals with a rebound tonometer. Superior collicular retinal ganglion cells were retrogradely labeled from the superior colliculus with Fluorogold. Melanopsin-containing retinal ganglion cells were visualized by free-floating immunohistochemistry on whole-mount retinas. The number of labeled superior collicular and melanopsin-containing retinal ganglion cells were counted in the sample areas on flat-mounted retinas. Results Compared with contralateral control eyes, the numbers of both superior collicular and melanopsin-containing retinal ganglion cells were significantly reduced after 12 weeks of experimental intraocular pressure elevation （（2317.41±29.96）/mm^2 vs （1815.82±24.25）/mm^2; （26.20±2.10）/mm^2 vs （20.62±1.52）/mm^2, respectively）. The extent of cell loss of the two types of retinal ganglion cells was similar. However, no morphologic changes were found in melanopsin-containing retinal ganglion cells. Conclusion Both melanopsin-containing and superior collicular retinal ganglion cells were damaged by chronic ocular hypertension, indicating that glaucomatous neural degeneration involves the non-image-forming visual pathway.
基金This study was supported by the grants from the National Natural Science Foundation of China （No. 30400229）, and Beijing Natural Science Foundation （No. 7052016）.Acknowledgements： We greatly thank Mrs. WANG Jin-jin for the assistant of the cell culture techniques.
文摘Background Latanoprost, a prostaglandin F2α analog, has been shown to be an effective intraocular pressure lowering agent which acts by inducing ciliary muscle cells to synthesise matrix metalloproteinases. However, the response of ciliary melanocytes to latanoprost has never been reported. This research has investigated the ability of latanoprost to induce matrix metalloproteinase-1 expression in human ciliary melanocytes, and thereby advance the understanding of the mechanism of PGF2α in decreasing intraocular pressure. Methods In vitro human ciliary melanocytes were treated for 48 hours with five different concentrations of latanoprost （100, 150, 200, 500, and 1000 nmol/L）. Ciliary melanocytes treated with 0.01% ethanol （vehicle） were used as a control. The expression of matrix metalloproteinase-1 in ciliary melanocytes was determined by Western blotting and immunofluorescent staining. Results Western blotting showed that the expression of matrix metalloproteinase-1 in ciliary melanocytes was induced by latanoprost, and the level of expression was dependent on the concentration of latanoprost in the culture medium. Immunofluorescent staining showed that matrix metalloproteinase-1 was confined to the ciliary melanocyte cytoplasm. Conclusions Latanoprost induced the expression of matrix metalloproteinase-1 in human ciliary melanocytes in a dose-dependent manner. Ciliary melanocytes, as well as ciliary muscle cells, may also play an important role in uveoscleral outflow modulation.
基金This study was supported by a grant from the Scientific Foundationfor Backbone Teachers with Innovating Ability of Common College inHeilongjiang Province (No.1055G059)
文摘Choroidal neovascularization （CNV）, a major cause of vision loss, is the result of the increased vascular endothelial growth factor （VEGF） expression in human retinal pigment epithelial （RPE） cells. It is important to inhibit the expression of VEGF protein in RPE cells.
基金This study was supported in part from grants of National Natural Science Foundation of China （No. 30973261 and No. 30571991）.
文摘Background Proneurotrophins such as the precursor of nerve growth factor （proNGF） and the precursor of brain-derived neurotrophic factor （proBDNF） interacted with sortilin and p75NTR to form a complex capable of activating an apoptotic signaling. We found that the expression of p75NTR and sortilin was increased in ischemic retina induced by elevated intraocular pressure （lOP）, but the protein expression changes of proNGF and proBDNF in the same situation were not clear. This study aimed to ascertain the protein expression changes of proNGF and proBDNF in ischemic retina induced by elevated lOP.
文摘Background Studies indicated that Mer might be the main contributor to the specific internalization of photoreceptor outer segments （POS） in retinal pigment epithelium （RPE）. It is very important to understand the mechanism of POS phagocytosis under the pathway of Mer and its ligands. The objective of this study was to identify changes in gene expression profiles caused by Mergene knockout （Mer-/-） during phagocytosis of POS in RPE. Methods RPE from both Mer-/- and wild-type （WT） mice were isolated and cultured to the 3rd passage. POS were subjected to culture medium with 20 nmol/L Gas6 and protein S to activate specific mer-mediated phagocytosis. RPE phagocytosis was evaluated by phagocytosis assays and differential gene expression identified by microarray at 3 and 12 hours; the 0-hour time point served as the control. Three independent samples for each Mer-/- or WT RPE were subjected to the same protocol of microarray. Five genes were confirmed by real-time quantitative PCR （QPCR）. Results The Mer-/- RPE had less internalized POS than WT RPE after both 3 and 12 hours in phagocytosis assay. Compared to WT RPE and the 0-hour control, 38 and 45 different known genes were increased and 68 and 59 known genes were decreased in Mer-/- RPE after 3 and 12 hours, respectively. Abnormal POS phagocytosis in Mer-/- RPE was associated with significant gene expression changes in, for example, signal transduction （WNT, MAPK）, phagocytosis （Vav3, Hsdllb1）, cytoskeleton components （Myo7a）, and metabolism, in a time-specific manner. QPCR results showed Vav3, Hsdllb1, Myo7a, Rtn2 and Itga8 in those independent samples were consistent with microarray. Conclusion Gene expression profiles modulated in a time-specific manner in Mer-/- RPE indicate a possible internalization mechanism for abnormal POS phagocytosis, which gives insight into the mechanism of retinitis pigmentosa caused by the mutation of MerTK in humans.
