Inhibition of EGFR attenuates EGF-induced activation of retinal pigment epithelium cell via EGFR/AKT signaling pathway

AIM:To explore the effect of epidermal growth factor receptor(EGFR)inhibition by erlotinib and EGFR siRNA on epidermal growth factor(EGF)-induced activation of retinal pigment epithelium(RPE)cells.METHODS:Human RPE cell line(ARPE-19 cells)was activated by 100 ng/mL EGF.Erlotinib and EGFR siRNA were used to intervene EGF treatment.Cellular viability,proliferation,and migration were detected by methyl thiazolyl tetrazolium(MTT)assay,bromodeoxyuridine(BrdU)staining assay and wound healing assay,respectively.EGFR/protein kinase B(AKT)pathway proteins and N-cadherin,α-smooth muscle actin(α-SMA),and vimentin were tested by Western blot assay.EGFR was also determined by immunofluorescence staining.RESULTS:EGF treatment for 24h induced a significant increase of ARPE-19 cells’viability,proliferation and migration,phosphorylation of EGFR/AKT proteins,and decreased total EGFR expression.Erlotinib suppressed ARPE-19 cells’viability,proliferation and migration through down regulating total EGFR and AKT protein expressions.Erlotinib also inhibited EGF-induced an increase of proliferative and migrative ability in ARPE-19 cells and clearly suppressed EGF-induced EGFR/AKT proteins phosphorylation and decreased expression of N-cadherin,α-SMA,and vimentin proteins.Similarly,EGFR inhibition by EGFR siRNA significantly affected EGF-induced an increase of cell proliferation,viability,and migration,phosphorylation of EGFR/AKT proteins,and up-regulation of N-cadherin,α-SMA,and vimentin proteins.CONCLUSION:Erlotinib and EGFR-knockdown suppress EGF-induced cell viability,proliferation,and migration via EGFR/AKT pathway in RPE cells.EGFR inhibition may be a possible therapeutic approach for proliferative vitreoretinopathy(PVR).

Hepatocyte growth factor promotes retinal pigment epithelium cell activity through MET/AKT signaling pathway

AIM:To explore the effects of hepatocyte growth factor(HGF)on retinal pigment epithelium(RPE)cell behaviors.METHODS:The human adult retinal pigment epithelial cell line-19(ARPE-19)were treated by HGF or mesenchymalepithelial transition factor(MET)inhibitor SU11274 in vitro.Cell viability was detected by a Cell Counting Kit-8 assay.Cell proliferation and motility was detected by a bromodeoxyuridine incorporation assay and a wound healing assay,respectively.The expression levels of MET,phosphorylated MET,protein kinase B(AKT),and phosphorylated AKT proteins were determined by Western blot assay.The MET and phosphorylated MET proteins were also determined by immunofluorescence assay.RESULTS:HGF increased ARPE-19 cells’viability,proliferation and migration,and induced an increase of phosphorylated MET and phosphorylated AKT proteins.SU11274 significantly reduced cell viability,proliferation,and migration and decreased the expression of MET and AKT proteins.SU11274 suppressed HGF-induced increase of viability,proliferation,and migration in ARPE-19 cells.Additionally,SU11274 also blocked HGF-induced phosphorylation of MET and AKT proteins.CONCLUSION:HGF enhances cellular viability,proliferation,and migration in RPE cells through the MET/AKT signaling pathway,whereas this enhancement is suppressed by the MET inhibitor SU11274.HGF-induced MET/AKT signaling might be a vital contributor of RPE cells survival.

光相干断层扫描血管成像观察新生血管性ARMD的临床研究

目的:利用光相干断层扫描血管成像(optical coherence tomography angiography,OCTA)观察新生血管性年龄相关性黄斑变性(neovascular age-related macular degeneration,n ARMD)患者的脉络膜新生血管(choroidal neovascularization,CNV)及接受抗血管内皮生长因子(vascular endothelial growth factor,VEGF)治疗前后的变化。方法:本研究为病例系列分析研究。纳入2017-05/12就诊于我院眼科的n ARMD患者29例37眼。所有患者玻璃体腔注射抗VEGF治疗前和治疗后1d,1wk,1mo及每月随访时均行OCTA检查,共随访3～6mo,观察抗VEGF治疗前后CNV病灶形态和大小、中心凹旁浅层视网膜血管密度和血流灌注的变化。结果:n ARMD患者CNV病灶的组织结构中不成熟的结构、小分支血管和毛细血管对抗VEGF的治疗应答反应较好;术前基线病灶面积为1. 27±1. 88mm2,术后第1d病灶面积为1. 13±1. 79mm2,CNV病灶在抗VEGF治疗后1d即可缩小,最终病灶大小稳定在1mo时的病灶面积水平,与治疗前比较差异有统计学意义(P=0. 001);抗VEGF治疗后3mo,中心凹旁浅层视网膜血管密度和血流灌注明显降低,差异有统计学意义(P=0. 003、0. 015)。结论:OCTA能够无创、清晰地显示n ARMD患者CNV病灶的细微结构变化和定量分析CNV病灶面积的变化。OCTA还能够对视网膜血管进行分层显示,定量分析视网膜微循环的变化,在nARMD患者的病情监测和指导治疗方面有重要的临床应用价值。

羊膜移植在眼部疾病治疗中的应用研究进展

羊膜是人胎盘中最内层的膜,支持上皮化,具有抗纤维化、抗炎、抗血管生成等特性,在眼科手术和其他外科手术中的应用逐渐广泛。最近几年羊膜在眼科临床的使用逐渐频繁,并且取得较好的疗效。本文就近年来羊膜移植在眼部烧伤、结膜病变、角膜病变、翼状胬肉、青光眼以及黄斑裂孔等眼部疾病中的应用进展进行综述,期待羊膜移植为眼部疾病治疗带来新的思路。

Potassium voltage-gated channel subfamily H member 2(KCNH2)is a promising target for incretin secretagogue therapies

Derived from enteroendocrine cells(EECs),glucagon-like peptide-1(GLP-1)and glucose-dependent insulinotropic peptide(GIP)are pivotal incretin hormones crucial for blood glucose regulation.Medications of GLP-1 analogs and GLP-1 receptor activators are extensively used in the treatment of type 2 diabetes(T2D)and obesity.However,there are currently no agents to stimulate endogenous incretin secretion.Here,we find the pivotal role of KCNH2 potassium channels in the regulation of incretin secretion.Co-localization of KCNH2 with incretin-secreting EECs in the intestinal epithelium of rodents highlights its significance.Gut epithelial cell-specific KCNH2 knockout in mice improves glucose tolerance and increases oral glucose-triggered GLP-1 and GIP secretion,particularly GIP.Furthermore,KCNH2-deficient primary intestinal epithelial cells exhibit heightened incretin,especially GIP secretion upon nutrient stimulation.Mechanistically,KCNH2 knockdown in EECs leads to reduced K+currents,prolonged action potential duration,and elevated intracellular calcium levels.Finally,we found that dofetilide,a KCNH2-specific inhibitor,could promote incretin secretion in enteroendocrine STC-1 cells in vitro and in hyperglycemic mice in vivo.These findings elucidate,for the first time,the mechanism and application of KCNH2 in regulating incretin secretion by EECs.Given the therapeutic promise of GLP-1 and GIP in diabetes and obesity management,this study advances our understanding of incretin regulation,paving the way for potential incretin secretagogue therapies in the treatment of diabetes and obesity.