Role of apigenin in high glucose-induced retinal microvascular endothelial cell dysfunction via regulating NOX4/p38 MAPK pathway in vitro

AIM:To investigate the retinoprotective role of Apigenin(Api)against high glucose(HG)-induced human retinal microvascular endothelial cells(HRMECs),and to explore its regulatory mechanism.METHODS:HRMECs were stimulated by HG for 48h to establish the in vitro cell model.Different concentrations of Api(2.5,5,and 10μmol/L)were applied for treatment.Cell counting kit-8(CCK-8),Transwell,and tube formation assays were performed to examine the effects of Api on the viability,migration,and angiogenesis in HG-induced HRMECs.Vascular permeability was evaluated by Evans blue dye.The inflammatory cytokines and oxidative stress-related factors were measured using their commercial kits.Protein expression of nicotinamide adenine dinucleotide phosphate(NADPH)oxidase 4(NOX4)and p38 mitogen-activated protein kinase(MAPK)was measured by Western blot.RESULTS:Api prevented HG-induced HRMECs viability,migration,angiogenesis,and vascular permeability in a concentration-dependent manner.Meanwhile,Api also concentration-dependently inhibited inflammation and oxidative stress in HRMECs exposed to HG.In addition,HG caused an elevated expression of NOX4,which was retarded by Api treatment.HG stimulation facilitated the activation of p38 MAPK signaling in HRMECs,and Api could weaken this activation partly via downregulating NOX4 expression.Furthermore,overexpression of NOX4 or activation of p38 MAPK signaling greatly weakened the protective role of Api against HG-stimulated HRMECs.CONCLUSION:Api might exert a beneficial role in HGstimulated HRMECs through regulating NOX4/p38 MAPK pathway.

Down-regulation of histone deacetylase 7 reduces biological activities of retinal microvascular endothelial cells under high glucose condition and related mechanism

AIM:To investigate the expression and effect of histone deacetylase 7(HDAC7)in human retinal microvascular endothelial cells(HRMECs)under high glucose condition and related mechanism,and the expression of HDAC7 in the retinal tissue in diabetic rats.METHODS:The expression of HDAC7 in HRMECs under high glucose and the retinal tissue from normal or diabetic rats were detected with immunohistochemistry and Western blot.LV-shHDAC7 HRMECs were used to study the effect of HDAC7 on cell activities.Cell count kit-8(CCK-8),5-ethynyl2’-deoxyuridine(EdU),flow cytometry,scratch test,Transwell test and tube formation assay were used to examine the ability of cell proliferation,migration,and angiogenesis.Finally,a preliminary exploration of its mechanism was performed by Western blot.RESULTS:The expression of HDAC7 was both upregulated in retinal tissues of diabetic rats and high glucosetreated HRMECs.Down-regulation of HDAC7 expression significantly reduced the ability of proliferation,migration,and tube formation,and reversed the high glucose-induced high expression of CDK1/Cyclin B1 and vascular endothelial growth factor in high glucose-treated HRMECs.CONCLUSION:High glucose can up-regulate the expression of HDAC7 in HRMECs.Down-regulation of HDAC7 can inhibit HRMECs activities.HDAC7 is proposed to be involved in pathogenesis of diabetic retinopathy and a therapeutic target.

Adenoviral 15-lipoxygenase-1 gene transfer inhibits hypoxia-induced proliferation of retinal microvascular endothelial cells in vitro

AIM: To investigate whether 15-Lipoxygenase-1 (15-LOX-1) plays an important role in the regulation of angiogenesis, inhibiting hypoxia-induced proliferation of retinal microvascular endothelial cells (RMVECs) and the underlying mechanism. METHODS: Primary RMVECs were isolated from the retinas of C57/BL63 mice and identified by an evaluation for FITC-marked CD31. The hypoxia models were established with the Bio-bag and evaluated with a blood-gas analyzer. Experiments were performed using RMVECs treated with and without transfer. Ad-15-LOX-1 or Ad-vector both under hypoxia and normoxia condition at 12, 24, 48, 72 hours. The efficacy of the gene transfer was assessed by immunofluorescence staining. Cells proliferation was evaluated by the CCK-8 method. RNA and protein expressions of 15-LOX-1, VEGF-A, VEGFR-2, eNOs and PPAR-r were analyzed by real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blot. RESULTS: Routine evaluation for FITC-marked CD31 showed that cells were pure. The results of blood-gas analysis showed that when the cultures were exposed to hypoxia for more than 2 hours, the Po2 was 4.5 to 5.4 Kpa. We verified RMVECs could be infected with Ad-LS-LOX-for Ad-vectorvia Fluorescence microscopy. CCK-8 analysis revealed that the proliferative capacities of RMVECs in hypoxic group were significantly higher at each time point than they were in normoxic group (P <0.05). In a hypoxic condition, the proliferative capacities of RMVECs in 15-LOX-1 group were significantly inhibited (P<0.05). Real-time RT-PCR analysis revealed that the expressions of VEGF-A, VEGF-R2 and eNOs mRNA increased in hypoxia group compared with normoxia group (P<0.01). However, the expressions of 15-LOX-1, PPAR-r mRNA decreased in hypoxia group compared with normoxia group (P<0.01). It also showed that in a hypoxic condition, the expressions of VEGF-A, VEGF-R2 and eNOs mRNA decreased significantly in 15-LOX-1 group compared with hypoxia group (P<0.01). However, 15-LOX-1 and PPAR-r mRNA increased significantly in 15-LOX-1 group compared with hypoxia group (P<0.01). There was no significant difference of the mRNA expressions between vector group and hypoxia group (P>0.05). Western blot analysis revealed that the expressions of relative proteins were also ranked in that order. CONCLUSION: Our results suggested that 15-LOX-1 and PPAR-r might act as a negative regulator of retinal angiogenesis. And the effect of 15-LOX-1 overexpression is an anti-angiogenic factor in hypoxia-induced retinal neovascularization (RNV). Overexpression 15-LOX-1 on RMVECs of hypoxia-induced RNV blocked signaling cascades by inhibiting hypoxia-induced increases in VEGF family. PPAR-r effect on VEGFR(2) could be an additional mechanism whereby 15-LOX-1 inhibited the hypoxia-induced RNV.

Autophagy activation and the mechanism of retinal microvascular endothelial cells in hypoxia

AIM： To explore the state of autophagy and related mechanisms in the murine retinal microvascular endothelial cells（RMECs） under hypoxia stimulation.METHODS： The murine RMECs were primarily cultured and randomly divided into three groups： hypoxia group（cultured in 1% O_2 environment）, hypoxia＋autophagy inhibition group [pretreated with 5 mmol/L 3-methyladenine（3-MA） for 4 h followed by incubation in 1% O_2] and control group（cultured under normoxic condition）. The state of autophagy in RMECs was examined by assaying the turnover of light chain 3 B（LC3BB） and expression of Beclin-1, Atg3 and Atg5 proteins with Western blotting, by detecting formation of autophagosomes with transmission electron microscopy（TEM） and by counting the number of GFP＋ puncta in RMECs. The protein levels of AMPK, P-AMPK, Akt, P-Akt, m-TOR and P-m TOR were also assayed by Western blotting.RESULTS： Primary murine RMECs were successfully cultured. Under hypoxic conditions, the ratio of LC3BB-Ⅱ/Ⅰ and the expression of Beclin-1, Atg3 and Atg5 proteins were increased when compared with the control group. In addition, the numbers of autophagosome and the GFP＋ puncta were also increased under hypoxia. However, pretreatment with 3-MA obviously attenuated these changes in autophagy in RMECs under hypoxia. Protein expression of P-Akt and P-AMPK was increased but P-m TOR level was decreased in cells exposed to hypoxia. CONCLUSION： In murine RMECs autophagy is activated under hypoxia possibly through activation of the AMPK/mTOR signaling pathway.

Trimethylamine N-oxide aggravates vascular permeability and endothelial cell dysfunction under diabetic condition:in vitro and in vivo study

AIM:To provide the direct evidence for the crucial role of trimethylamine N-oxide(TMAO)in vascular permeability and endothelial cell dysfunction under diabetic condition.METHODS:The role of TMAO on the in vitro biological effect of human retinal microvascular endothelial cells(HRMEC)under high glucose conditions was tested by a cell counting kit,wound healing,a transwell and a tube formation assay.The inflammation-related gene expression affected by TMAO was tested by real-time polymerase chain reaction(RT-PCR).The expression of the cell junction was measured by Western blotting(WB)and immunofluorescence staining.In addition,two groups of rat models,diabetic and non-diabetic,were fed with normal or 0.1%TMAO for 16wk,and their plasma levels of TMAO,vascular endothelial growth factor(VEGF),interleukin(IL)-6 and tumor necrosis factor(TNF)-αwere tested.The vascular permeability of rat retinas was measured using FITC-Dextran,and the expression of zonula occludens(ZO)-1 and claudin-5 in rat retinas was detected by WB or immunofluorescence staining.RESULTS:TMAO administration significantly increased the cell proliferation,migration,and tube formation of primary HRMEC either in normal or high-glucose conditions.RT-PCR showed elevated inflammation-related gene expression of HRMEC under TMAO stimulation,while WB or immunofluorescence staining indicated decreased cell junction ZO-1 and occludin expression after high-glucose and TMAO treatment.Diabetic rats showed higher plasma levels of TMAO as well as retinal vascular leakage,which were even higher in TMAO-feeding diabetic rats.Furthermore,TMAO administration increased the rat plasma levels of VEGF,IL-6 and TNF-αwhile decreasing the retinal expression levels of ZO-1 and claudin-5.CONCLUSION:TMAO enhances the proliferation,migration,and tube formation of HRMEC,as well as destroys their vascular integrity and tight connection.It also regulates the expression of VEGF,IL-6,and TNF-α.

Genipin relieves diabetic retinopathy by down-regulation of advanced glycation end products via the mitochondrial metabolism related signaling pathway

BACKGROUND Glycation is an important step in aging and oxidative stress,which can lead to endothelial dysfunction and cause severe damage to the eyes or kidneys of diabetics.Inhibition of the formation of advanced glycation end products(AGEs)and their cell toxicity can be a useful therapeutic strategy in the prevention of diabetic retinopathy(DR).Gardenia jasminoides Ellis(GJE)fruit is a selective inhibitor of AGEs.Genipin is an active compound of GJE fruit,which can be employed to treat diabetes.AIM To confirm the effect of genipin,a vital component of GJE fruit,in preventing human retinal microvascular endothelial cells(hRMECs)from AGEs damage in DR,to investigate the effect of genipin in the down-regulation of AGEs expression,and to explore the role of the CHGA/UCP2/glucose transporter 1(GLUT1)signal pathway in this process.METHODS In vitro,cell viability was tested to determine the effects of different doses of glucose and genipin in hRMECs.Cell Counting Kit-8(CCK-8),colony formation assay,flow cytometry,immunofluorescence,wound healing assay,transwell assay,and tube-forming assay were used to detect the effect of genipin on hRMECs cultured in high glucose conditions.In vivo,streptozotocin(STZ)induced mice were used,and genipin was administered by intraocular injection(IOI).To explore the effect and mechanism of genipin in diabetic-induced retinal dysfunction,reactive oxygen species(ROS),mitochondrial membrane potential(MMP),and 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose(2-NBDG)assays were performed to explore energy metabolism and oxidative stress damage in high glucose-induced hRMECs and STZ mouse retinas.Immunofluorescence and Western blot were used to investigate the expression of inflammatory cytokines[vascular endothelial growth factor(VEGF),SCG3,tumor necrosis factor-alpha(TNF-α),interleukin(IL)-1β,IL-18,and nucleotide-binding domain,leucine-rich-containing family,pyrin domain-containing 3(NLRP3)].The protein expression of the receptor of AGEs(RAGE)and the mitochondria-related signal molecules CHGA,GLUT1,and UCP2 in high glucose-induced hRMECs and STZ mouse retinas were measured and compared with the genipin-treated group.RESULTS The results of CCK-8 and colony formation assay showed that genipin promoted cell viability in high glucose(30 mmol/L D-Glucose)-induced hRMECs,especially at a 0.4μmol/L dose for 7 d.Flow cytometry results showed that high glucose can increase apoptosis rate by 30%,and genipin alleviated cell apoptosis in AGEs-induced hRMECs.A high glucose environment promoted ATP,ROS,MMP,and 2-NBDG levels,while genipin inhibited these phenotypic abnormalities in AGEs-induced hRMECs.Furthermore,genipin remarkably reduced the levels of the pro-inflammatory cytokines TNF-α,IL-1β,IL-18,and NLRP3 and impeded the expression of VEGF and SCG3 in AGEs-damaged hRMECs.These results showed that genipin can reverse high glucose induced damage with regard to cell proliferation and apoptosis in vitro,while reducing energy metabolism,oxidative stress,and inflammatory injury caused by high glucose.In addition,ROS levels and glucose uptake levels were higher in the retina from the untreated eye than in the genipin-treated eye of STZ mice.The expression of inflammatory cytokines and pathway protein in the untreated eye compared with the genipin-treated eye was significantly increased,as measured by Western blot.These results showed that IOI of genipin reduced the expression of CHGA,UCP2,and GLUT1,maintained the retinal structure,and decreased ROS,glucose uptake,and inflammation levels in vivo.In addition,we found that SCG3 expression might have a higher sensitivity in DR than VEGF as a diagnostic marker at the protein level.CONCLUSION Our study suggested that genipin ameliorates AGEs-induced hRMECs proliferation,apoptosis,energy metabolism,oxidative stress,and inflammatory injury,partially via the CHGA/UCP2/GLUT1 pathway.Control of advanced glycation by IOI of genipin may represent a strategy to prevent severe retinopathy and vision loss.

玄参提取物对糖尿病视网膜病变微血管内皮细胞损伤的影响及其作用机制

目的:探讨玄参提取物抑制微小RNA-646(miR-646)改善微血管内皮细胞损伤缓解糖尿病视网膜水肿的影响及其作用机制。方法:根据简单随机化法将人视网膜微血管内皮细胞(HRMEC)细胞分为对照组、模型组(30 mmol/L葡萄糖)、观察组(30 mmol/L葡萄糖+100μg/mL玄参提取物组)、模型+Anti-NC(转染Anti-NC+30 mmol/L葡萄糖)、模型+Anti-miR-646(转染Anti-miR-646+30 mmol/L葡萄糖)组;将30只小鼠根据简单随机化法分为对照组、模型组(60 mg/kg的链脲佐菌素)、观察组(60 mg/kg的链脲佐菌素+100 mg/kg-的玄参提取物),每组10只。比较各组细胞增殖,迁移及miR-646、血管内皮生长因子A(VEGFA)、细胞间黏附分子-1(ICAM-1)、血小板-内皮细胞黏附分子(CD31)表达;比较各组小鼠视网膜组织ICAM-1、CD31表达及视网膜组织水肿情况。结果:细胞实验结果显示,与对照组比较,模型组细胞miR-646、ICAM-1表达显著升高,VEGFA、CD31表达显著下降(均P<0.05);与模型组比较,观察组细胞miR-646、ICAM-1表达显著降低,VEGFA、CD31表达显著升高(均P<0.05);与模型+Anti-NC组比较,模型+Anti-miR-646组细胞增殖率、迁移细胞数及VEGFA表达显著增加,miR-646表达及凋亡率显著降低(均P<0.05)。动物实验结果显示,与对照组比较,模型组小鼠视网膜组织中miR-646、ICAM-1表达显著升高,VEGFA、CD31表达显著下降(均P<0.05),同时小鼠视网膜组织水肿情况加重;与模型组比较,观察组小鼠网膜组织中miR-646、ICAM-1表达显著降低,VEGFA、CD31表达显著升高(均P<0.05),同时小鼠视网膜组织水肿明显得到缓解。结论:玄参提取物可能通过miR-646/VEGFA机制调节HRMEC细胞增殖、迁移和凋亡,改善缓解糖尿病视网膜水肿。

连翘苷通过调控CTRP3表达对高糖诱导的人视网膜血管内皮细胞损伤的影响及其机制研究

目的比较不同剂量连翘苷(PHN)对高糖(HG)诱导的人视网膜血管内皮细胞损伤的影响,并分析其对补体C1q/肿瘤坏死因子相关蛋白3(CTRP3)表达的调控作用及可能的作用机制。方法采用HG培养人视网膜血管内皮细胞并建立细胞损伤模型(HG组)。HG+PHN-L组、HG+PHN-M组、HG+PHN-H组人视网膜血管内皮细胞分别用1μmol·L^(-1)、10μmol·L^(-1)、100μmol·L^(-1)PHN处理后进行HG诱导。HG+pcDNA组、HG+pcDNA-CTRP3组分别用pcDNA、pcDNA-CTRP3转染至人视网膜血管内皮细胞后进行HG诱导。HG+PHN-H+sh-NC组、HG+PHN-H+sh-CTRP3组分别用sh-NC、sh-CTRP3转染后,用100μmol·L^(-1)PHN处理HG诱导的人视网膜血管内皮细胞。检测细胞丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)水平。采用流式细胞术检测细胞凋亡率。采用实时荧光定量聚合酶链反应(qRT-PCR)、Western blot分别检测B淋巴细胞瘤-2(Bcl-2)、Bcl-2相关蛋白(Bax)、CTRP3蛋白表达水平。结果与Con组比较,HG组细胞凋亡率、MDA水平、Bax蛋白水平均升高,SOD、GSH-Px、Bcl-2蛋白、CTRP3 mRNA及蛋白水平均降低(均为P<0.05)。与HG组比较,HG+PHN-L组、HG+PHN-M组、HG+PHN-H组细胞凋亡率、MDA水平、Bax蛋白水平均降低,且HG+PHN-H组<HG+PHN-M组<HG+PHN-L组(均为P<0.05),SOD、GSH-Px、Bcl-2蛋白、CTRP3 mRNA及蛋白水平均升高,且HG+PHN-H组>HG+PHN-M组>HG+PHN-L组(均为P<0.05)。与HG+pcDNA组比较,HG+pcDNA-CTRP3组细胞凋亡率、MDA水平、Bax蛋白水平均降低,SOD、GSH-Px、CTRP3蛋白、Bcl-2蛋白水平均升高(均为P<0.05)。与HG+PHN-H+sh-NC组比较,HG+PHN-H+sh-CTRP3组细胞凋亡率、MDA水平、Bax蛋白水平均升高,SOD水平、GSH-Px水平、CTRP3蛋白、Bcl-2蛋白水平均降低(均为P<0.05)。结论PHN可减轻HG诱导的人视网膜血管内皮细胞损伤,其作用机制可能与上调CTRP3表达有关。

基于腺苷酸活化蛋白激酶/哺乳动物雷帕霉素靶蛋白通路探讨柚皮素对视网膜微血管内皮细胞的损伤机制研究

目的 基于腺苷酸活化蛋白激酶(AMPK)/哺乳动物雷帕霉素靶蛋白(mTOR)通路探讨柚皮素(NAR)对人视网膜微血管内皮细胞(HRMECs)的损伤机制。方法 将HRMECs随机分为对照组、高糖(HG)组、HG+NAR组(3 mg/L NAR)、HG+激活剂(AICAR)组(1 mmol/L AICAR)、HG+NAR+AICAR组(3 mg/L NAR+1 mmol/L AICAR);除对照组向培养基中加入5 mmol/L的D-葡萄糖处理外,其他各组均向培养基中加入30 mmol/L的D-葡萄糖处理。采用CCK-8及Transwell分别检测细胞增殖及迁移情况;采用酶联免疫吸附试验(ELISA)检测上清液中白细胞介素(IL)-1β、IL-6和肿瘤坏死因子-α(TNF-α)水平;采用实时荧光定量聚合酶链反应(qRT-PCR)检测自噬因子LC3 mRNA、p62 mRNA表达水平;采用蛋白质免疫印迹(Western blot)检测AMPK/mTOR通路及自噬相关蛋白表达水平。结果 与对照组相比,HG组细胞活力,迁移数,IL-1β、IL-6和TNF-α水平,p-AMPK/AMPK,LC3Ⅱ/LC3Ⅰ,LC3 mRNA表达增加,p-mTOR/mTOR、p62蛋白及p62 mRNA表达下降,差异有统计学意义(P<0.05);与HG组相比,HG+NAR组细胞活力,迁移数,IL-1β、IL-6和TNF-α水平,p-AMPK/AMPK,LC3Ⅱ/LC3Ⅰ,LC3 mRNA表达下降,p-mTOR/mTOR、p62蛋白及p62 mRNA表达增加,但HG+AICAR组细胞活力,迁移数,IL-1β、IL-6和TNF-α水平,p-AMPK/AMPK,LC3Ⅱ/LC3Ⅰ表达增加,p-mTOR/mTOR、p62蛋白及p62 mRNA表达下降,差异有统计学意义(P<0.05);与HG+NAR组相比,HG+NAR+AICAR组细胞活力,迁移数,IL-1β、IL-6和TNF-α水平,p-AMPK/AMPK,LC3Ⅱ/LC3Ⅰ,LC3 mRNA表达增加,p-mTOR/mTOR、p62蛋白及p62 mRNA表达下降,差异有统计学意义(P<0.05);与HG+AICAR组相比,HG+NAR+AICAR组细胞活力,迁移数,IL-1β、IL-6和TNF-α水平,p-AMPK/AMPK,LC3Ⅱ/LC3Ⅰ,LC3 mRNA表达下降,p-mTOR/mTOR、p62蛋白及p62 mRNA表达增加,差异有统计学意义(P<0.05)。结论 NAR可减轻HG诱导的HRMECs损伤,其机制可能与抑制AMPK/mTOR通路介导的自噬有关。

舒洛地特激活AMPK/SIRT1通路减轻高糖诱导的大鼠心肌微血管内皮细胞损伤

目的:探讨舒洛地特(SDX)减轻高糖(HG)诱导的大鼠心肌微血管内皮细胞(CMEC)氧化应激和凋亡的作用及其机制。方法:分离培养大鼠CMEC,随机分为对照组、HG组、HG+SDX组。CCK-8法检测细胞存活率。利用DCFH-DA作为荧光探针,测定各组DCF荧光强度以判定细胞内活性氧(ROS)水平。比较各组细胞上清液中超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量。采用流式细胞术和TUNEL法检测细胞凋亡率,western blotting法检测AMPK、磷酸化(p-)AMPK、SIRT1蛋白表达。结果:与对照组相比,HG组CMEC细胞存活率降低,细胞上清液中MDA含量增高,SOD活性降低,ROS水平和细胞凋亡率升高,p-AMPK、SIRT1蛋白表达水平下降(均P<0.05)。与HG组比较,HG+SDX组CMEC的细胞存活率显著提升,MDA、ROS生成减少,SOD活性升高,CMEC凋亡率下降,p-AMPK、SIRT1蛋白表达水平升高(均P<0.05)。结论:SDX可能通过激活AMPK/SIRT1信号通路,减轻HG诱导的CMEC的氧化应激及细胞凋亡,从而发挥心血管保护作用。

miR-519d-3p靶向HIF-1α抑制高糖诱导的人视网膜微血管内皮细胞功能障碍及血管生成

目的:明确miR-519d-3p对高糖诱导的人视网膜微血管内皮细胞(HRMEC)功能障碍与血管生成的影响,并阐明其对低氧诱导因子-1α(HIF-1α)的调控机制。方法:通过5、30mmol/L葡萄糖分别诱导HRMEC建立正常(NG)和高糖(HG)细胞模型。将HRMEC分为对照组(HG细胞模型转染阴性对照模拟物)、甘露醇组(对照组加入25mmol/L甘露醇)、miR-519d-3p过表达组(HG细胞模型转染miR-519d-3p模拟物)、miR-519d-3p联合HIF-1α过表达组(HG细胞模型共转染miR-519d-3p模拟物和HIF-1α过表达载体)。实时荧光定量PCR法检测各组miR-519d-3p的表达情况。Western blotting法检测各组HIF-1α蛋白的表达情况。荧光素酶报告基因实验检测miR-519d-3p和HIF-1α的结合位点情况。CCK-8法检测各组细胞增殖情况。Hoechst 33342染色法检测各组细胞凋亡情况。ELISA法检测各组细胞外液炎症因子肿瘤坏死因子-α(TNF-α)、白细胞介素(IL)-1β、IL-6蛋白的表达情况。小管形成实验检测各组新生毛细血管管腔样结构形成情况。结果:与NG相比,HG细胞模型中miR-519d-3p表达显著减少,而HIF-1α蛋白表达显著增加(均P<0.01)。与对照组比较,miR-519d-3p过表达组中HIF-1α蛋白表达显著降低(P<0.01)。miR-519d-3p中“CGUGAAA”序列可以与HIF-1α3'-非编码区(3'-UTR)中“GCACUUU”序列特异性结合。与对照组比较,miR-519d-3p过表达组细胞24、48、72h吸光度值均显著增加,细胞凋亡率显著减少,细胞外液TNF-α、IL-1β、IL-6浓度均显著减少,新生毛细血管管腔样结构数量显著减少(均P<0.01)。与miR-519d-3p过表达组比较,miR-519d-3p联合HIF-1α过表达组细胞24、48、72h吸光度值均显著减少,细胞凋亡率显著增加,细胞外液TNF-α、IL-1β、IL-6浓度均显著增加,新生毛细血管管腔样结构数量显著增加(均P<0.01)。对照组和甘露醇组中上述各指标比较无差异(均P>0.05)。结论:高糖诱导HRMEC模型中miR-519d-3p表达下调,而HIF-1α蛋白表达上调。HIF-1α是miR-519d-3p的靶基因,miR-519d-3p靶向HIF-1α增加细胞增殖并降低细胞凋亡和炎症反应,从而减轻高糖诱导的HRMEC功能障碍并抑制血管生成。

miR-1-3p调控ANXA2表达对高糖诱导的视网膜微血管内皮细胞新生血管生成的影响

目的 探讨微小RNA-1-3p(miR-1-3p)/膜联蛋白A2(ANXA2)分子轴在高糖诱导的人视网膜微血管内皮细胞(HRMECs)新生血管生成过程中的作用机制。方法 体外培养HRMECs并采用高糖(HG)处理细胞建立细胞损伤模型。HRMECs分组处理:Con组(含体积分数10%胎牛血清的DMEM培养)、HG组(25 mmol·L^(-1)D-葡萄糖培养)、HG+miR-NC组(转染miR-NC)、HG+miR-1-3p组(转染miR-1-3p mimics)、HG+sh-NC组(转染sh-NC)、HG+sh-ANXA2组(转染sh-ANXA2)、HG+miR-1-3p+pcDNA组(转染miR-1-3p mimics+pcDNA)、HG+miR-1-3p+pcDNA-ANXA2组(转染miR-1-3p mimics+pcDNA-ANXA2)。转染48 h后收集细胞,采用25 mmol·L^(-1)的D-葡萄糖培养基培养HRMECs 24 h。采用MTT、Transwell小室实验分别检测细胞活力、迁移细胞数。管腔形成实验检测管腔形成数。双荧光素酶报告实验检测miR-1-3p与ANXA2的靶向关系。Western blot检测VEGF、MMP-2蛋白水平。结果 与Con组比较,HG组miR-1-3p表达水平降低,ANXA2 mRNA及蛋白水平均升高,差异均有统计学意义(均为P<0.05)。与Con组比较,HG组细胞活力升高,迁移细胞数、管腔形成数增多,VEGF、MMP-2蛋白水平升高,差异均有统计学意义(均为P<0.05)。与HG+miR-NC组比较,HG+miR-1-3p组细胞活力降低,迁移细胞数、管腔形成数减少,VEGF、MMP-2蛋白水平降低,差异均有统计学意义(均为P<0.05)。与HG+sh-NC组比较,HG+sh-ANXA2组细胞活力降低,迁移细胞数、管腔形成数减少,VEGF、MMP-2蛋白水平降低,差异均有统计学意义(均为P<0.05)。与HG+miR-1-3p+pcDNA组比较,HG+miR-1-3p+pcDNA-ANXA2组细胞活力升高,迁移细胞数、管腔形成数增多,VEGF、MMP-2蛋白水平升高,差异均有统计学意义(均为P<0.05)。结论 miR-1-3p过表达可通过靶向调控ANXA2表达抑制HRMECs的增殖、迁移及新生血管生成。

胃饥饿素通过抑制内质网应激减少高糖诱导的视网膜血管内皮细胞凋亡

目的研究胃饥饿素(ghrelin)对内质网应激及高浓度葡萄糖导致的人视网膜血管内皮细胞(HRMECs)凋亡的影响。方法将HRMECs细胞分为对照组、高糖组、高糖+ghrelin组和高糖+ghrelin+衣霉素(内质网应激诱导剂)组。对照组细胞不加干预,高糖组采用30 mmol/L葡萄糖构建细胞损伤模型,高糖+ghrelin组采用30 mmol/L葡萄糖和10 nmol/L ghrelin处理细胞,高糖+ghrelin+衣霉素组采用30 mmol/L葡萄糖、10 nmol/L ghrelin和10μmol/L衣霉素联合处理细胞,所有细胞均培养48 h。采用AnnexinⅤ-FITC/7-AAD试剂盒检测4组细胞凋亡率,蛋白质印迹法检测对照组、高糖组和高糖+ghrelin组细胞凋亡蛋白Bax、Bcl-2及内质网应激蛋白GPR78、IRE1α的表达。结果与对照组比较,高糖组HRMECs细胞凋亡率明显升高(P<0.05);与高糖组相比,高糖+ghrelin组细胞凋亡率明显降低(P<0.05)。与对照组比较,高糖组细胞Bax、GPR78及p-IRE1α的蛋白表达明显增加(均P<0.05),Bcl-2的表达明显降低(P<0.05);与高糖组相比,高糖+ghrelin组细胞Bax、GPR78及p-IRE1α的蛋白表达均明显降低(均P<0.05),Bcl-2的表达明显升高(P<0.05)。与高糖+ghrelin组相比,高糖+ghrelin+衣霉素组的细胞凋亡率明显升高(P<0.05)。结论Ghrelin可以减少高糖诱导的视网膜血管内皮细胞凋亡,其机制可能与ghrelin抑制激活的内质网应激有关。

补阳还五汤对高糖培养的人视网膜微血管内皮细胞自噬和血管形成的干预作用

目的探究补阳还五汤(BYHW)对高糖培养的人视网膜微血管内皮细胞(HRCECs)自噬影响和血管形成的干预作用。方法将HRCECs随机分为对照组(CG)、模型组(MG)、BYHW组、自噬抑制剂3-甲基腺嘌呤(3-MA)组。除CG组外,其余各组细胞于25 g/L葡萄糖环境中培养建立高糖损伤模型,BYHW组在MG组的基础上加入5 mg/mL的BYHW水提液,3-MA组加入40μM的3-MA,各组细胞均孵育24 h。采用血管形成实验检测HRCECs血管生成情况,划痕实验检测细胞迁移能力,实时荧光定量PCR(RT-qPCR)和Western Blot法分别检测细胞中微管相关蛋白1A/1B-轻链3(LC3)、苄氯素1(Becline-1)的mRNA和蛋白表达水平。结果(1)血管形成:与CG组比较,MG组血管形成数升高(t=7.747,P=0.000);与MG组比较,BYHW、3-MA组血管形成数降低(t_(BYHW)=-6.303,P=0.000;t_(3-MA)=-4.596,P=0.002),差异均有统计学意义。而BYHW、3-MA组血管形成数比较,差异无统计学意义(P>0.05)。(2)迁移能力:与CG组比较,MG组HRCECs迁移率升高(t=14.035,P=0.000);与MG组比较,BYHW、3-MA组HRCECs迁移率降低(t_(BYHW)=-9.247,t_(3-MA)=-5.358,均P=0.000);与BYHW组比较,3-MA组HRCECs迁移率升高(t=-3.890,P=0.003),差异均有统计学意义。(3)自噬:与CG组比较,MG组LC3 mRNA、蛋白表达水平升高(t_(mRNA)=8.249,t_(蛋白)=14.890,均P=0.000),Beclin-1蛋白表达水平升高(t=7.114,P=0.000);与MG组比较,BYHW、3-MA组的LC3 mRNA和蛋白表达水平均降低(BYHW:t_(mRNA)=-9.298,t_(蛋白)=-11.727,均P=0.000。3-MA:t_(mRNA)=-3.718,P=0.006;t_(蛋白)=-7.511,P=0.000),BYHW组的Beclin-1蛋白表达水平下降(t=-4.115,P=0.003);与BYHW组比较,3-MA组HRCECs的Beclin-1蛋白表达水平升高(t=-2.448,P=0.038),差异均有统计学意义。结论BYHW延缓非增殖期糖尿病视网膜病的发展可能与其调控HRCECs自噬减少血管形成和迁移有关。

Piezo拮抗剂GsMTx4通过激活Yap1/STAT3信号通路促进人视网膜微血管内皮细胞的血管生成

目的探讨Piezo拮抗剂GsMTx4对人视网膜微血管内皮细胞(hRMECs)血管生成能力的影响与机制。方法体外培养hRMECs,随机分为对照组、GsMTx4组、GsMTx4+维替泊芬(VP)组、GsMTx4+Stattic组。GsMTx4组用2.5μmol·L^(-1)的GsMTx4处理细胞24 h,GsMTx4+VP组用GsMTx4联合Yap1的拮抗剂VP(4μmol·L^(-1))处理hRMECs 24 h,GsMTx4+Stattic组则用GsMTx4联合STAT3的拮抗剂Stattic(1.5μmol·L^(-1))处理hRMECs 24 h。CCK-8法检测各组hRMECs的增殖能力。小管形成实验观察各组hRMECs的血管生成能力,记录小管分支数。qRT-PCR和Western blot检测对照组和GsMTx4组hRMECs中Piezo、Yap1、STAT3 mRNA和蛋白的表达水平。使用免疫共沉淀技术检测各组hRMECs中Yap1和STAT3的结合作用。结果与对照组相比,GsMTx4组hRMECs的增殖率和小管分支数均明显增加(均为P<0.05),Piezo蛋白表达下调,而Yap1、STAT3蛋白表达均上调,且Yap1和STAT3的结合作用明显增加(均为P<0.05)。与GsMTx4组相比,GsMTx4+VP组和GsMTx4+Stattic组hRMECs中Yap1和STAT3的蛋白表达均下调,且Yap1和STAT3的结合作用减弱(均为P<0.05)。与GsMTx4组相比,GsMTx4+VP组和GsMTx4+Stattic组hRMECs增殖率和小管分支数均降低(均为P<0.05)。结论Piezo拮抗剂GsMTx4通过激活Yap1/STAT3信号通路促进hRMECs的血管生成。

二甲双胍对高糖诱导的RF/6A细胞增殖、迁移和血管形成的影响及其可能机制

目的研究二甲双胍(MET)对高糖诱导的恒河猴脉络膜⁃视网膜内皮细胞RF/6A增殖、迁移和血管形成的影响,并初步探讨其作用机制。方法RF/6A细胞随机分为5组:NC组、HG组、HG+15 mmol·L^(-1) MET组、HG+30 mmol·L^(-1) MET组、HG+45 mmol·L^(-1) MET组,CCK⁃8法检测细胞增殖情况。将RF/6A细胞随机分为4组:NC组和NC+15 mmol·L^(-1) MET组、NC+30 mmol·L^(-1) MET组、NC+45 mmol·L^(-1) MET组,CCK⁃8法检测MET的细胞毒性。将RF/6A细胞随机分为3组:NC组、HG组和HG+15 mmol·L^(-1) MET组,细胞划痕法和Transwell法检测细胞迁移,Matrigengel法检测细胞血管形成,RT⁃PCR、Western blot检测Hippo信号通路的核心成分YAP、TEAD1的mRNA及蛋白表达。结果CCK⁃8法检测结果显示,与NC组比较,HG组RF/6A细胞的增殖活性升高(P<0.001);与HG组比较,HG+15 mmol·L^(-1) MET组、HG+30 mmol·L^(-1) MET组和HG+45 mmol·L^(-1) MET组RF/6A细胞的增殖活性均降低(均为P<0.001)。与NC组比较,NC+15 mmol·L^(-1) MET组RF/6A细胞增殖活性无变化(P=0.2273),因此选择15 mmol·L^(-1) MET进行后续实验。细胞划痕法和Transwell法检测结果显示,与NC组比较,HG组RF/6A细胞的迁移率升高、迁移个数增加(均为P<0.01);与HG组比较,HG+15 mmol·L^(-1) MET组RF/6A细胞的迁移率降低、迁移个数减少(均为P<0.01)。Matrigengel法检测结果显示,与NC组比较,HG组RF/6A细胞的血管相对总长度增加(P<0.05);与HG组比较,HG+15 mmol·L^(-1) MET组RF/6A细胞的血管相对总长度减少(P<0.01)。RT⁃PCR检测结果显示,与NC组比较,HG组RF/6A细胞的YAP和TEAD1 mRNA相对表达量均增加(均为P<0.05);与HG组比较,HG+15 mmol·L^(-1) MET组RF/6A细胞的YAP和TEAD1 mRNA相对表达量均减少(均为P<0.05)。Western blot检测结果显示,与NC组比较,HG组RF/6A细胞的YAP和TEAD1蛋白相对表达量均增加(均为P<0.05);与HG组比较,HG+15 mmol·L^(-1) MET组RF/6A细胞的YAP和TEAD1蛋白相对表达量均减少(均为P<0.05)。结论MET可抑制高糖诱导的RF/6A细胞增殖、迁移和血管形成,下调YAP、TEAD1的mRNA及蛋白表达,推测其作用机制与Hippo信号通路有关。

S1PR1激活PI3K/Akt保护高糖环境下视网膜血管内皮细胞的生物学功能

目的研究1⁃磷酸鞘氨醇受体1(S1PR1)对高糖环境下人视网膜血管内皮细胞(HREC)的迁移、成管能力的影响,并进一步探讨其作用机制。方法将HREC随机分为空白病毒组、S1PR1过表达组、高糖+空白病毒组和高糖+S1PR1过表达组。采用细胞划痕及Transwell实验检测细胞迁移能力,成管实验检测细胞成管能力,并采用Western blot检测PI3K/Akt通路相关蛋白分子表达情况。结果与空白病毒组相比,高糖+空白病毒组的伤口愈合百分比、细胞迁移数量、成管分支点数及小管总长度均显著减少(均P<0.01);而与高糖+空白病毒组相比,高糖+S1PR1过表达组均显著增多(均P<0.01)。各组间PI3K、Akt总蛋白表达差异均无统计学意义均无显著差异(均P>0.05),而p⁃PI3K、p⁃Akt蛋白表达差异均有统计学意义均具有显著性差异(均P<0.01);与空白病毒组相比,高糖+空白病毒组的p⁃PI3K、p⁃Akt均显著减少(均P<0.01);而与高糖+空白病毒组相比,高糖+S1PR1过表达组均显著增多(均P<0.01)。结论S1PR1通过激活PI3K/Akt通路,保护高糖环境下HREC的迁移及成管能力。

树鼩视网膜微血管内皮细胞永生化细胞株的建立及鉴定

目的建立树鼩视网膜来源的微血管内皮细胞的体外分离培养技术以及永生化细胞株,为体外利用树鼩视网膜微血管内皮细胞开展相关研究提供新的实验材料。方法利用Ⅱ型胶原酶、分散酶和DNaseⅠ酶消化法分离培养出原代视网膜微血管内皮细胞,利用差速消化法纯化内皮细胞,然后利用携带SV40T基因的慢病毒转染细胞,再挑取单克隆后进行传代培养。对传至50代以上的细胞进行形态学观察、免疫荧光鉴定以及核型鉴定。结果采用混合酶消化法能够分离获得微血管内皮细胞,纯化后的细胞呈不规则多角形和梭形。经慢病毒转染后的细胞传代培养后细胞形态一致,到第50代时细胞形态结构仍较好。细胞免疫荧光结果显示标志性蛋白VWF、CD34、Claudin1、ZO-1和永生化SV40T表达阳性。生长曲线结果显示:细胞生长旺盛,第2~4天时处于对数生长期,第4天进入平台期。细胞核型结果显示:染色体数与树鼩染色体相同,即所获取的细胞为永生化的树鼩视网膜微血管内皮细胞。结论成功建立的树鼩视网膜微血管内皮细胞永生化细胞株具有较好的形态结构与功能,为视网膜病变及眼科相关疾病的研究提供了新的实验材料。

化瘀明目方含药血清对高糖诱导的HRMECs功能紊乱模型血管形成的作用及机制研究

目的探究化瘀明目方含药血清对高糖诱导的人视网膜微血管内皮细胞(Human retinal microvascular endothelial cells,HRMECs)血管形成的影响及可能机制。方法CCK-8法筛选合适的糖浓度和含药血清体积分数,建立单纯高糖因素诱导的HRMECs功能紊乱模型。将HRMECs分为6组,正常对照组予以正常ECM培养基(含5.5 mmol·L^(-1)葡萄糖)+10%空白血清;甘露醇对照组、模型组在正常对照组基础上分别加入19.5 mmol·L^(-1)甘露醇、19.5 mmol·L^(-1)D-葡萄糖;化瘀明目方低、中、高剂量组在模型组基础上分别加入10%低、中、高剂量含药血清(不加空白血清)。克隆实验检测细胞集落形成数,Transwell实验检测细胞迁移数,管腔形成实验检测细胞成管数,免疫荧光实验、Western Blot实验和RT-PCR实验检测第八因子(FactorⅧ)、血小板内皮细胞黏附分子1(CD31)、细胞分化因子(CD34)、血管内皮生长因子A(VEGFA)、血管内皮生长因子受体2(VEGFR2)蛋白及mRNA表达水平。结果与正常对照组比较,模型组能够促进HRMECs集落形成(P<0.01)、细胞迁移(P<0.01)、管腔形成(P<0.01),FactorⅧ、CD31、CD34、VEGFA、VEGFR2蛋白及mRNA表达水平明显升高(P<0.01);与模型组比较,化瘀明目方低、中、高剂量含药血清抑制HRMECs集落形成(P<0.05,P<0.01)、细胞迁移(P<0.01)、管腔形成(P<0.05,P<0.01),FactorⅧ、CD31、CD34、VEGFA、VEGFR2蛋白及mRNA表达水平明显降低(P<0.05,P<0.01);正常对照组与甘露醇对照组间各项检测的差异均无统计学意义(P>0.05)。结论化瘀明目方含药血清能够抑制高糖诱导下HRMECs细胞的增殖、迁移和管腔形成,预防或减轻血管新生,其机制可能与调控VEGFA/VEGFR2信号通路有关。

桃红四物汤对糖尿病视网膜病变引起的细胞损伤及HIF-1α表达的影响

目的探究桃红四物汤对高糖诱导的人视网膜微血管内皮细胞(hRMECs)的保护作用及潜在的分子机制。方法①取hRMECs,设置5组:空白对照组加5 mmol/L葡萄糖培养,高糖模型组加30 mmol/L葡萄糖培养,桃红四物汤低、中、高剂量组分别加30 mmol/L葡萄糖和相应浓度桃红四物汤含药血清培养,通过Transwell和划痕实验检测细胞的侵袭和迁移能力,血管生成实验检测细胞的成管能力,ELISA试剂盒检测细胞中血管内皮生长因子(VEGF)水平,Western blot法检测细胞中缺氧诱导因子-1α(HIF-1α)蛋白表达情况。②另外设置4组:空白对照组加5 mmol/L葡萄糖培养,高糖模型组加30 mmol/L葡萄糖培养,桃红四物汤组加30 mmol/L葡萄糖和高剂量桃红四物汤含药血清培养,桃红四物汤+HIF-1α过表达组采用HIF-1α过表达的hRMECs细胞加30 mmol/L葡萄糖和高剂量桃红四物汤含药血清培养,考察HIF-1α过表达对桃红四物汤的功能回复作用。结果①与空白对照组比较,高糖模型组细胞侵袭和迁移能力均明显增强(P均<0.05),成管数量明显增多(P<0.05),VEGF水平和HIF-1α蛋白相对表达量均明显增加(P均<0.05)。与高糖模型组比较,桃红四物汤高剂量组细胞的侵袭和迁移能力均明显降低(P均<0.05),成管数量明显减少(P均<0.05),VEGF水平和HIF-1α蛋白相对表达量均明显降低(P均<0.05)。②与高糖模型组比较,桃红四物汤组细胞的侵袭和迁移能力均明显降低(P均<0.05),成管数量明显减少(P均<0.05),VEGF水平和HIF-1α蛋白相对表达量均明显降低(P均<0.05);与桃红四物汤组比较,桃红四物汤+HIF-1α过表达组细胞侵袭和迁移能力均明显增强(P均<0.05),VEGF水平和HIF-1α蛋白相对表达量均明显升高(P均<0.05)。结论桃红四物汤通过下调HIF-1α的表达减轻糖尿病视网膜病变引起的细胞损伤。