RESUMO
Vascular endothelial growth factor (VEGF) signaling is crucial for choroidal neovascularization (CNV), a major pathological feature of neovascular age-related macular degeneration (nAMD). Gene transcription of VEGF is mainly regulated by hypoxia-inducible factor 1-alpha (HIF-1α). The chromobox (CBX) family polycomb protein (Pc) subgroup includes CBX2, CBX4, CBX6, CBX7, and CBX8. CBX4 enhances hypoxia-induced VEGF expression and angiogenesis in hepatocellular carcinoma (HCC) cells by increasing HIF-1α's transcriptional activity. The objective of the study was to examine the functions of members of the CBX family Pc subgroup in choroidal vascular endothelial cells (CVECs) during CNV. CBX4 and CBX7 expression was up-regulated in hypoxic human choroidal vascular endothelial cells (HCVECs). In HCVECs, CBX7 facilitated HIF-1α transcription and expression, while CBX4 did not. In HCVECs, CBX7 stimulated HIF-1α's nuclear translocation and transcriptional activity, which in turn stimulated VEGF transcription and expression. The CBX7/HIF-1α/VEGF pathway promoted the migration, proliferation, and tube formation of HCVECs. The CBX7/HIF-1α/VEGF pathway was up-regulated in CVECs and in the mouse model with laser-induced CNV. Mouse CNV was lessened by the blockade of CBX7 through the down-regulation of HIF-1α/VEGF. In conclusion, CBX7 enhanced pro-angiogenic behaviors of hypoxic CVECs by up-regulating the HIF-1α/VEGF pathway, which contributing to the formation of mouse laser-induced CNV.
Assuntos
Corioide , Neovascularização de Coroide , Modelos Animais de Doenças , Subunidade alfa do Fator 1 Induzível por Hipóxia , Camundongos Endogâmicos C57BL , Complexo Repressor Polycomb 1 , Fator A de Crescimento do Endotélio Vascular , Neovascularização de Coroide/metabolismo , Neovascularização de Coroide/patologia , Neovascularização de Coroide/genética , Animais , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Camundongos , Complexo Repressor Polycomb 1/metabolismo , Complexo Repressor Polycomb 1/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Humanos , Corioide/irrigação sanguínea , Corioide/metabolismo , Transdução de Sinais/fisiologia , Células Cultivadas , Western Blotting , Proliferação de Células/fisiologia , Células Endoteliais/metabolismo , Regulação da Expressão Gênica , Endotélio Vascular/metabolismo , Endotélio Vascular/patologia , Movimento Celular , Reação em Cadeia da Polimerase em Tempo RealRESUMO
OBJECTIVES: To investigate the effects of newborn bull serum(NBS), vitamin C and vitamin E on cryopreservation of mouse seminiferous epithelial cells. METHODS: The seminiferous epithelial cells from 7-day-old mice were cryopreserved in different freezing solutions. The cell recoveries were examined by Trypan blue exclusive staining after thawing. The freezing solutions composed of DMEM, 10% dimethylsulphoxide(DMSO), and 0, 5%, 10%, or 20% NBS, respectively, or composed of DMEM, 10% DMSO, 10% NBS, and 150 micrograms/ml vitamin C or 50 micrograms/ml vitamin E, respectively. RESULTS: The cell recoveries in freezing solution containing 0, 5%, 10%, or 20% NBS were 83.4%, 84.7%, 85.7% and 83.6%, respectively. There were no significant differences between them. The cell recoveries in freezing solution containing vitamin C or vitamin E were 88.0% and 82.9%, respectively. There was no significant differences compared with that in freezing solution containing 10% DMSO and 10% NBS. CONCLUSIONS: NBS, vitamin C and vitamin E have no significant protecting effects on mouse seminiferous epithelial cells, and can not significantly improve the cell recoveries.