Knockdown of fibrillin-1 suppresses retina-blood barrier dysfunction by inhibiting vascular endothelial apoptosis under diabetic conditions

AIM:To investigate the effects of fibrillin-1(FBN1)deletion on the integrity of retina-blood barrier function and the apoptosis of vascular endothelial cells under diabetic conditions.METHODS:Streptozotocin(STZ)-induced diabetic mice were used to simulate the diabetic conditions of diabetic retinopathy(DR)patients,and FBN1 expression was detected in retinas from STZ-diabetic mice and controls.In the Gene Expression Omnibus(GEO)database,the GSE60436 dataset was selected to analyze FBN1 expressions in fibrovascular membranes from DR patients.Using lentivirus to knock down FBN1 levels,vascular leakage and endothelial barrier integrity were detected by Evans blue vascular permeability assay,fluorescein fundus angiography(FFA)and immunofluorescence labeled with tight junction marker in vivo.High glucose-induced monkey retinal vascular endothelial cells(RF/6A)were used to investigate effects of FBN1 on the cells in vitro.The vascular endothelial barrier integrity and apoptosis were detected by trans-endothelial electrical resistance(TEER)assay and flow cytometry,respectively.RESULTS:FBN1 mRNA expression was increased in retinas of STZ-induced diabetic mice and fibrovascular membranes of DR patients(GSE60436 datasets)using RNA-seq approach.Besides,knocking down of FBN1 by lentivirus intravitreal injection significantly inhibited the vascular leakage compared to STZ-DR group by Evans blue vascular permeability assay and FFA detection.Expressions of tight junction markers in STZ-DR mouse retinas were lower than those in the control group,and knocking down of FBN1 increased the tight junction levels.In vitro,30 mmol/L glucose could significantly inhibit viability of RF/6A cells,and FBN1 mRNA expression was increased under 30 mmol/L glucose stimulation.Down-regulation of FBN1 reduced high glucose(HG)-stimulated retinal microvascular endothelial cell permeability,increased TEER,and inhibited RF/6A cell apoptosis in vitro.CONCLUSION:The expression level of FBN1 increases in retinas and vascular endothelial cells under diabetic conditions.Down-regulation of FBN1 protects the retina of early diabetic rats from retina-blood barrier damage,reduce vascular leakage,cell apoptosis,and maintain vascular endothelial cell barrier function.

Erythropoietin Receptor Positive Circulating Progenitor Cells and Endothelial Progenitor Cells in Patients with Different Stages of Diabetic Retinopathy

Objective To investigate the possible involvement of erythropoietin （EPO）/erythropoietin receptor （EPOR） system in neovascularization and vascular regeneration in diabetic retinopathy （DR）. Methods EPOR positive circulating progenitor cells （CPCs： CD34^＋） and endothelial progenitor cells （EPCs： CD34^＋KDR^＋） were assessed by flow cytometry in type 2 diabetic patients with different stages of DR. The cohort consisted of age- and sex-matched control patients without diabetes （n=7）, non-prolif- erative DR （NPDR, n=7）, proliferative DR （PDR, n=8）, and PDR complicated with diabetic nephropathy （PDR-DN, n=7）. Results The numbers of EPOR^＋ CPCs and EPOR^＋ EPCs were reduced remarkably in NPDR corn pared with the control group （both P（0.01）, whereas rebounded in PDR and PDR-DN groups in varying degrees. Similar changes were observed in respect of the proportion of EPOR^＋ CPCs in CPCs （NPDR vs. control, P（0.01） and that of EPOR^＋ EPCs in EPCs （NPDR vs. control, P〈0.05）. Conclusion Exogenous EPO, mediated via the EPO/EPOR system of EPCs, may alleviate the impaired vascular regeneration in NPDR, whereas it might aggravate retinal neovascularization in PDR due to a rebound of EPOR^＋ EPCs associated with ischemia.

Effects of nuclear factor κB expression on retinal neovascularization and apoptosis in a diabetic retinopathy rat model

AIM: To investigate the expression and role of nuclear factor κB(NF-κB) in diabetic retinopathy(DR) and its relationship with neovascularization and retinal cell apoptosis. METHODS: A total of 80 male Wistar rats were randomly assigned to control(4, 8, 12 and 16 wk, n =10 in each group) and diabetes mellitus(DM) groups(4, 8, 12 and 16wk, n =10 in each group). A diabetic rat model was established by intraperitoneal injection of streptozotocin(60 mg/kg). After 4, 8, 12 and 16 wk, rats were sacrificed.Retinal layers and retinal neovascularization growth were stained with hematoxylin-eosin and examined under light microscopy. Cell apoptosis in the retina was detected by Td T-mediated d UTP nick end labeling, and NF-κB distribution and expression in the retina was determined using immunohistochemistry. RESULTS: DM model success rate up to 100%.Diabetes model at each time point after the experimental groupcompared with the control group, the blood glucose was significantly increased, decreased body weight, each time point showed significant differences compared with the control group(P 【0.01). After 12 wk other pathological changes in the retina of diabetic rats were observed; after 16 wk, neovascularization were observed. After 1mo, retinal cell apoptosis was observed.Compared with the control group, NF-κB expression in the DM group significantly increased with disease duration.CONCLUSION: With the prolonging of DM progression,the expression NF-κB increases. NF-κB may be related to retinal cell apoptosis and neovascularization.

Inflammation in diabetic retinopathy: possible roles in pathogenesis and potential implications for therapy

Diabetic retinopathy, characterized as a microangiopathy and neurodegenerative disease, is the leading cause of visual impairment in diabetic patients. Many clinical features observed in diabetic retinopathy, such as capillary occlusion, acellular capillaries and retinal non-perfusion, aggregate retinal ischemia and represent relatively late events in diabetic retinopathy. In fact, retinal microvascular injury is an early event in diabetic retinopathy involving multiple biochemical alterations, and is manifested by changes to the retinal neurovascular unit and its cellular components. Currently, intravitreal anti-vascular endothelial growth factor therapy is the firstline treatment for diabetic macular edema, and benefits the patient by decreasing the edema and improving visual acuity. However, a significant proportion of patients respond poorly to anti-vascular endothelial growth factor treatments, indicating that factors other than vascular endothelial growth factor are involved in the pathogenesis of diabetic macular edema. Accumulating evidence confirms that low-grade inflammation plays a critical role in the pathogenesis and development of diabetic retinopathy as multiple inflammatory factors, such as interleukin-1β, monocyte chemotactic protein-1 and tumor necrosis factor-α, are increased in the vitreous and retina of diabetic retinopathy patients. These inflammatory factors, together with growth factors such as vascular endothelial growth factor, contribute to blood-retinal barrier breakdown, vascular damage and neuroinflammation, as well as pathological angiogenesis in diabetic retinopathy, complicated by diabetic macular edema and proliferative diabetic retinopathy. In addition, retinal cell types including microglia, Müller glia, astrocytes, retinal pigment epithelial cells, and others are activated, to secrete inflammatory mediators, aggravating cell apoptosis and subsequent vascular leakage. New therapies, targeting these inflammatory molecules or related signaling pathways, have the potential to inhibit retinal inflammation and prevent diabetic retinopathy progression. Here, we review the relevant literature to date, summarize the inflammatory mechanisms underlying the pathogenesis of diabetic retinopathy, and propose inflammation-based treatments for diabetic retinopathy and diabetic macular edema.

Study and analysis of oxidative stress and cell apoptosis in retinal tissue of diabetic model rats after total flavonoids of onion treatment

Objective:To study the effect of total flavonoids of onion treatment on oxidative stress and cell apoptosis in the retinal tissue of diabetic model rats.Methods:Male SD rats were selected as experimental animals and randomly divided into control group, diabetes group, low-dosage total flavonoids group (total flavonoids L group) and high-dose total flavonoids (total flavonoids H group), intraperitoneal injection of streptozotocin was adopted to make diabetes model, and the total flavonoids L group and H group received lavage of 100 mg/kg and 200 mg/kg total flavonoids of onion for intervention. After 8 weeks of intervention, retinal tissue was collected and the degree of oxidative stress and cell apoptosis were determined.Results:P2X7, ROS, -OH, O2-, H2O2, FADD, p-JNK, caspase-8 and caspase-3 levels in retinal tissue of diabetes group were significantly higher than those of control group while Mn-SOD, CAT, GSH, AsA, NGF, BDNF and CNTF levels were significantly lower than those of control group;P2X7, ROS, -OH, O2-, H2O2, FADD, p-JNK, caspase-8 and caspase-3 levels in retinal tissue of total flavonoids L group and total flavonoids H group were significantly lower than those of diabetes group while Mn-SOD, CAT, GSH, AsA, NGF, BDNF and CNTF levels were significantly higher than those of diabetes group;P2X7, ROS, -OH, O2-, H2O2, FADD, p-JNK, caspase-8 and caspase-3 levels in retinal tissue of total flavonoids H group were significantly lower than those of total flavonoids L group while Mn-SOD, CAT, GSH, AsA, NGF, BDNF and CNTF levels were significantly higher than those of total flavonoids L group.Conclusion:Total flavonoids of onion have inhibiting effect on the oxidative stress and cell apoptosis in retinal tissue of diabetic model rats.

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.

α1-antitrypsin combined with bone marrow mesenchymal stem cells regulates retinopathy in diabetic rats via p38 MAPK/NF-κB signaling pathway

Objective:To investigate the effect ofα1-antitrypsin combined with bone marrow mesenchymal stem cells on retinopathy in diabetic rats and its mechanism.Methods:A model of diabetic retinopathy was established by intraperitoneal injection of streptozotocin.The 30 Wistar rats successfully modeled were randomly divided into a model group,a bone marrow mesenchymal stem cell group and a combined group(α1-antitrypsin combined with bone marrow Mesenchymal stem cells),the blood glucose and serum insulin levels of diabetic rats were measured 4 weeks after treatment.Enzyme-linked immunosorbent assay(ELISA)for measuring serum inflammatory factors IL-1β,IL-6 and TNF-α in rats.Observing the pathological morphology of rat retina under hematoxylin-eosin staining(HE).TUNEL staining to observe the apoptosis of rat retinal nerve cells.Immunohistochemical method to detect the expression level of CD45 in retinal tissue.Real-time fluorescence quantitative PCR was used to detect the expression of retinal vascular endothelial growth factor(VEGF),hypoxiainducible factor-1α(HIF-1α),and angiotensinⅡ(ANGⅡ)mRNA.Western blot was used to detect the expression of p38 MAPK/NF-κB signaling pathway-related proteins in the retinal tissue of each group of rats.Results:Compared with the control group,the rats in the model group had increased blood glucose,decreased insulin levels,increased serum IL-1β,IL-6,and TNF-α levels,and had obvious lesions in the retina.CD45 showed high expression in retinal tissue,VEGF,HIF-1α,ANGⅡ mRNA expression increased,p-p38,p-p65,p-IκBα protein expression increased(P<0.05).Compared with the model group,the bone marrow mesenchymal stem cell group and the combined group have decreased blood glucose,increased insulin levels,and decreased serum IL-1β,IL-6 and TNF-α levels.Retinopathy is improved,apoptosis of retinal nerve cells is reduced,CD45 expression in retinal tissue is reduced,VEGF,HIF-1α,ANGⅡ mRNA expression is decreased,and p-p38,p-p65,p-IκBα protein expression is decreased.Compared with the bone marrow mesenchymal stem cell group,the effect of the combined group was more obvious(P<0.05).Conclusion:α1-antitrypsin combined with bone marrow mesenchymal stem cell transplantation can improve the degree of retinopathy in diabetic rats.The mechanism may be related to the inhibition of p38 MAPK/NF-κB signaling pathway.

Integrin β5 subunit regulates hyperglycemia-induced vascular endothelial cell apoptosis through FoxO1-mediated macroautophagy

Background:Hyperglycemia frequently induces apoptosis in endothelial cells and ultimately contributes to microvascular dysfunction in patients with diabetes mellitus(DM).Previous research reported that the expression of integrins as well as their ligands was elevated in the diseased vessels of DM patients.However,the association between integrins and hyperglycemia-induced cell death is still unclear.This research was designed to investigate the role played by integrin subunit β5(ITGB5)in hyperglycemia-induced endothelial cell apoptosis.Methods:We used leptin receptor knockout(Lepr-KO)(db/db)mice as spontaneous diabetes animal model.Selective deletion of ITGB5 in endothelial cell was achieved by injecting vascular targeted adeno-associated virus via tail vein.Besides,we also applied small interfering RNA in vitro to study the mechanism of ITGB5 in regulating high glucose-induced cell apoptosis.Results:ITGB5 and its ligand,fibronectin,were both upregulated after exposure to high glucose in vivo and in vitro.ITGB5 knockdown alleviated hyperglycemia-induced vascular endothelial cell apoptosis and microvascular rarefaction in vivo.In vitro analysis revealed that knockdown of either ITGB5 or fibronectin ameliorated high glucose-induced apoptosis in human umbilical vascular endothelial cells(HUVECs).In addition,knockdown of ITGB5 inhibited fibronectin-induced HUVEC apoptosis,which indicated that the fibronectin-ITGB5 interaction participated in high glucose-induced endothelial cell apoptosis.By using RNA-sequencing technology and bioinformatic analysis,we identified Forkhead Box Protein O1(FoxO1)as an important downstream target regulated by ITGB5.Moreover,we demonstrated that the excessive macroautophagy induced by high glucose can contribute to HUVEC apoptosis,which was regulated by the ITGB5-FoxO1 axis.Conclusion:The study revealed that high glucose-induced endothelial cell apoptosis was positively regulated by ITGB5,which suggested that ITGB5 could potentially be used to predict and treat DM-related vascular complications.

Effect of Tanshinone IIA on High Glucose-induced Apoptosis and Oxidative Stress Damage in Vascular Endothelial Cells

Objective:The primary cause of microvascular disease in diabetic complications is long-term hyperglycemia,wherein the damage and apoptosis of vascular endothelial cells play a significant role.Sodium tanshinone IIA sulfonate(STS)has been found to have beneficial effects on cardiovascular health.This study aimed to investigate the impact of STS on high glucose-induced apoptosis and oxidative stress damage in vascular endothelial cells,as well as its potential protective mechanisms.Methods:Human umbilical vein endothelial cells(HUVECs)were divided into five groups:low-glucose group,high-glucose group,and three STS groups(STS-a,STS-b,and STS-c).The low-glucose group was incubated with DMEM low-sugar medium containing 5.5 mmol·L-1glucose,while the high-glucose group was treated with 33.3mmol·L-1glucose.The STS groups were exposed to 10,30,and 50μg·m L-1of STS,respectively.Each group was cultured for 72 h,and the MTT method was utilized to assess cell proliferation.Additionally,flow cytometry was employed to monitor changes in cell apoptosis and cellular oxidative stress indicators at 24,48,and 72 h of cell culture in each group.Results:As time went on,the cell proliferation ability and apoptosis rate of each group gradually increased.The high-glucose group exhibited lower proliferation ability compared to the other groups.The STS-c group demonstrated the highest OD value for proliferation ability(24 h:1.19±0.12;48 h:1.20±0.13;72 h:1.25±0.12),but it was still lower than that of the low-sugar group.Notably,the high-glucose group had the highest cell apoptosis rate,while the low-glucose group had the lowest.The apoptosis rate of the STS-c group(24 h:8.02±0.13;48 h:10.10±0.12;72 h:13.18±0.11)%was between that of the low-glucose group and the high-glucose group,and lower than the STS-a and STS-b groups.Furthermore,the high-glucose group exhibited the highest malondialdehyde and nitric oxide synthase activities,as well as superoxide dismutase activity and nitric oxide levels,whereas the low-glucose group showed the opposite pattern.The oxidative stress damage-related indicators of cells in the three STS groups were between those of the high-glucose and low-glucose groups,with the STS-c group displaying the most significant changes.Conclusion:Tanshinone IIA has a potential therapeutic effect on high glucose-induced vascular injury by improving the oxidative stress state of vascular endothelial cells and reducing cell apoptosis,which suggests a new strategy for preventing and treating diabetes-related microangiopathy.

Glucagon-like peptide-1 receptor agonists rescued diabetic vascular endothelial damage through suppression of aberrant STING signaling

Glucagon-like peptide-1 receptor agonists(GLP-1 RAs)protect against diabetic cardiovascular diseases and nephropathy.However,their activity in diabetic retinopathy(DR)remains unclear.Our retrospective cohort study involving 1626 T2DM patients revealed superior efficacy of GLP-1 RAs in controlling DR compared to other glucose-lowering medications,suggesting their advantage in DR treatment.By single-cell RNA-sequencing analysis and immunostaining,we observed a high expression of GLP-1R in retinal endothelial cells,which was down-regulated under diabetic conditions.Treatment of GLP-1 RAs significantly restored the receptor expression,resulting in an improvement in retinal degeneration,vascular tortuosity,avascular vessels,and vascular integrity in diabetic mice.GO and GSEA analyses further implicated enhanced mitochondrial gene translation and mitochondrial functions by GLP-1 RAs.Additionally,the treatment attenuated STING signaling activation in retinal endothelial cells,which is typically activated by leaked mitochondrial DNA.Expression of STING mRNA was positively correlated to the levels of angiogenic and inflammatory factors in the endothelial cells of human fibrovascular membranes.Further investigation revealed that the cAMP-responsive element binding protein played a role in the GLP-1R signaling pathway on suppression of STING signaling.This study demonstrates a novel role of GLP-1 RAs in the protection of diabetic retinal vasculature by inhibiting STING-elicited inflammatory signals.

神经调节蛋白4对2型糖尿病小鼠主动脉内皮细胞凋亡的影响

目的探讨神经调节蛋白4(Nrg4)对2型糖尿病小鼠主动脉内皮细胞凋亡的影响。方法将C57小鼠分为对照(Vehicle)组、糖尿病(DM)组和Nrg4干预糖尿病小鼠(Nrg4)组。Nrg4组腹腔注射Nrg4重组蛋白(100μg/kg,3次/周),Vehicle组与DM组小鼠注射等量生理盐水,干预周期均为8周。实验结束后,TUNEL荧光染色检测主动脉内皮细胞凋亡,Western blot检测主动脉内皮组织凋亡相关蛋白Bax、Bcl-2及Cleaved-caspase 3的表达。结果与Vehicle组相比,DM组主动脉内皮细胞凋亡率明显升高[(33.0±5.4)%vs.(20.5±3.0)%;P<0.05],促凋亡蛋白Bax与凋亡执行蛋白Cleaved-caspase 3表达明显增多,抗凋亡蛋白Bcl-2表达显著减少(P<0.05);而Nrg4干预明显抑制糖尿病小鼠主动脉内皮细胞凋亡[(19.2±3.8)%vs.(33.0±5.4)%;P<0.05],降低Bax与Cleaved-caspase 3的表达并促进Bcl-2表达(P<0.05)。结论Nrg4干预能缓解2型糖尿病小鼠主动脉内皮细胞凋亡。

The effects of glucose, insulin and oxidized low density lipoprotein on apoptosis in vascular endothelial cells

Obejctive To study the effects of high concentrations of glucose, insulin and oxidized low density lipoprotein (ox LDL) on apoptosis in cultured bovine aortic endothelial cells (ECs) Methods For qualitative determination of EC apoptosis, acridine orange (AO)/ethidium bromide (EB) staining and DNA agarose gels electrophoresis were used Cellular DNA fragmentation ELISA measured apoptosis by quantitating the fragmentation of 5 bromo 2' deoxyuridine labeled DNA Results High concentrations of glucose (20?mmol/L, 40?mmol/L), insulin (3000?μU/ml) and ox LDL (50?μg/ml, 100?μg/ml) induced concentration and time dependent apoptosis in ECs They had a synergetic effect on EC apoptosis The combined effect of high concentration of glucose, insulin and ox LDL was greater than any two of them; the effect of two was greater than one alone Low concentration of insulin (30?μU/ml) decreased apoptosis in ECs induced by high concentrations of glucose (40? mmol/L), but no similar effect occurred with ox LDL (100?μg/ml) Conclusion High ambient glucose, insulin and ox LDL can induce excessive apoptosis in cultured ECs, and low ambient insulin can prevent EC apoptosis Excessive EC apoptosis induced by the separate or synergetic effect of hyperglycemia, hyperinsulinemia and hyperlipidemia may be one of the reasons for loss of endothelial integrity, dysfunction of the vascular endothelium and increased plasma membrane permeability, which are all involved in the development of diabetic macrovascular complications

Mailuoning prevents high-glucose-mediated human umbilical vein endothelial cells apoptosis

OBJECTIVE： To investigated the role of Mailuoning in the prevention of highglucosemediated cell apoptosis in human umbilical vein endothelial cells （HUVEC） and the mechanisms involved. METHODS： MTT assay was used to investigate cell viability, western blot was used to investigate pro tein expression, and flow cytometric detection technology was used to detect cell apoptosis. RESULTS： Exposure of HUVEC to high glucose （50 mM） significantly suppressed cell viability and increased cell apoptosis compared with normal glu cose （11 mM） （all P〈0.05）. However, Mailuoning pre vented highglucoseinduced HUVEC apoptosis in dosedependent manner. Further studies indicated that Mailuoning suppressed highglucoseinduced p38 mitogenactivated protein kinase phosphoryla tion, but had no effect on extracellular signalregu lated kinase 1/2 and Akt phosphorylation. CONCLUSION： Mailuoning can prevent highglu coseinduced HUVEC apoptosis by suppressing p38 activation.

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。

DR视网膜内皮功能失调的研究进展

糖尿病视网膜病变(DR)是糖尿病最常见的眼部并发症,是工作人群及中老年人视力减退甚至失明的主要原因之一。在糖尿病微血管系统中,视网膜血管功能障碍由多种因素引起,高血糖通过不同的机制损伤视网膜内皮细胞、增加血管通透性、破坏血-视网膜屏障,导致视网膜内皮功能失调。其中,过氧化物酶体增殖物激活受体-y破坏、氧化应激、炎症、晚期糖基化终产物及其受体增加及microRNA失调等多种病理因素均可引起视网膜血管内皮损伤,加速视网膜内皮功能失调,从而导致DR的发生发展。文章旨在对各种病理因素所致视网膜内皮功能失调的相关机制进行综述,以深化我们对该疾病分子及细胞层面机制的理解,了解DR治疗过程中的挑战,为DR的临床管理和治疗提供新思路和策略。

基于网络药理学、分子对接及实验验证探讨滋肾健脾化瘀片对糖尿病视网膜病变的干预机制

目的运用网络药理学方法和分子对接技术探讨滋肾健脾化瘀片(山萸肉、三七、黄芪、葛根、鸡血藤、生地黄)治疗糖尿病视网膜病变(DR)的作用机制,并通过体外实验进行验证。方法(1)利用中药系统药理学数据库与分析平台(TCMSP)及BATMAN-TCM数据库筛选滋肾健脾化瘀片的有效成分及其对应的靶点蛋白。利用GeneCards、OMIM及TTD数据库检索DR疾病相关靶点。利用VENNY 2.1.0平台对药物活性成分靶点与DR疾病相关靶点取交集(共同靶点),即为滋肾健脾化瘀片治疗DR的潜在作用靶点。构建“中药-活性成分-共同靶点”网络,筛选出滋肾健脾化瘀片治疗DR的关键活性成分。将共同靶点导入STRING数据库,获取PPI网络关系,并筛选出核心靶点。运用Metascape平台对共同靶点进行GO功能及KEGG通路富集分析。将关键活性成分及核心靶点通过Autodock 4软件进行分子对接验证。(2)制备滋肾健脾化瘀片含药血清及空白血清。将人视网膜微血管内皮细胞(HRmECs)随机分成5组:对照组(低糖DMEM培养基+10%空白血清)、高糖组(高糖DMEM培养基+10%空白血清)及滋肾健脾化瘀片含药血清低、中、高剂量组(高糖DMEM培养基+10%低、中、高剂量含药血清),培养48 h后进行检测。采用CCK-8法检测HRmECs细胞增殖活性;RT-qPCR法检测HRmECs细胞中IL-1β、AKT1、VEGFA、TP53 mRNA表达水平。结果(1)共筛选出滋肾健脾化瘀片治疗DR的潜在作用靶点(共同靶点)74个;9个关键活性成分包括槲皮素、芒柄花黄素、毛地黄黄酮、β谷甾醇、山柰酚、毛蕊异黄酮、γ-氨基丁酸、豆甾醇、异鼠李亭;12个核心靶点:IL-1β、PPARG、NOS3、CXCL8、IL-6、AKT1、TNF、INS、EGF、VEGFA、TP53、PTGS2。GO功能及KEGG富集分析显示核心靶点主要参与了炎症反应、蛋白质磷酸化的正调控、细胞迁移等生物过程,以及NF-κB信号通路、AGE-RAGE信号通路、HIF-1通路、TNF通路、PI3K-AKT通路等。关键活性成分与核心靶点均具有较好的结合亲和力。(2)与对照组比较,高糖组HRmECs细胞活性显著降低(P<0.01);细胞中VEGFA、TP53、IL-1βmRNA表达水平显著升高(P<0.01),AKT1 mRNA表达水平显著降低(P<0.01)。与高糖组比较,滋肾健脾化瘀片含药血清低、中、高剂量组的HRmECs细胞活性均显著升高(P<0.05,P<0.01),并呈浓度依赖性;含药血清高剂量组细胞的VEGFA、TP53、IL-1βmRNA表达水平显著降低(P<0.05,P<0.01),而AKT1 mRNA表达水平显著升高(P<0.01)。结论滋肾健脾化瘀片可能通过槲皮素、山柰酚、毛地黄黄酮等多种活性成分,作用于IL-1β、IL-6、VEGFA等核心靶点,以及NF-κB信号通路、AGE-RAGE信号通路、PI3K-AKT通路等关键通路,从而发挥对DR的治疗作用。

超声乳化白内障吸除联合玻璃体切割及硅油填充术对糖尿病患者角膜的影响

目的 探究糖尿病视网膜病变患者行超声乳化白内障吸除(Phaco)联合玻璃体切割(PPV)及硅油填充术对角膜的影响。方法 选34例(34眼)视网膜病变患者为研究对象,根据是否合并糖尿病将患者分为糖尿病组与非糖尿病组,各17例(17眼)。所有患者均行Phaco联合PPV及硅油填充术治疗,记录两组并发症发生情况,术前及术后1周、1个月、3个月及6个月测量角膜内皮细胞密度(ECD)、中央角膜厚度(CCT)、角膜前表面曲率、角膜后表面曲率及角膜屈光度,比较两组间的角膜数据。结果 术后1周糖尿病组患者的ECD低于非糖尿病组,术后1周、1个月糖尿病组患者的CCT均厚于非糖尿病组,差异均有统计学意义(均P<0.05)。术后1周糖尿病组患者的角膜前表面曲率K1(平坦轴)的SIA值和角膜前表面曲率K2(陡峭轴)的SIA值均高于非糖尿病组,差异均有统计学意义(均P<0.05);术后1周、1个月、3个月、6个月两组患者术后角膜后表面曲率K1(平坦轴)的SIA值、角膜后表面曲率K2(陡峭轴)的SIA值比较,差异均无统计学意义(均P>0.05)。术后1周糖尿病组患者角膜屈光度的SIA值高于非糖尿病组患者,差异有统计学意义(P<0.05);术后1个月、3个月、6个月两组角膜屈光度的SIA值比较,差异均无统计学意义(均P>0.05)。两组患者均未发生超过24 h持续性高眼压,药物治疗后眼压维持正常,无感染性眼内炎发生。结论 Phaco联合PPV及硅油填充术对糖尿病患者角膜内皮细胞、CCT、角膜前表面曲率及角膜屈光度早期损伤较非糖尿病组更明显,但硅油填充后3—6个月内两组患者角膜内皮细胞、CCT、角膜前后表面曲率及角膜屈光度差异均无统计学意义。因此,Phaco联合PPV及硅油填充术对糖尿病视网膜病变患者是一种相对安全的手术方式。

Gpr124对高糖环境下视网膜微血管内皮细胞增殖、迁移和血管形成的调控作用

目的研究高糖环境下人视网膜微血管内皮细胞(human retinal microvascular endothelial cell,HRMEC)中G蛋白偶联受体124(Gpr124)表达的变化,以及干扰Gpr124对HRMEC的调控作用。方法免疫荧光观察Gpr124在HRMEC中的表达;高糖刺激HRMEC,将细胞分为空白组和高糖组,CCK-8、EdU检测细胞活力与增殖情况;病毒抑制Gpr124表达后,将细胞分为空白对照组、高糖对照组、高糖+shRNA组以及高糖+Gpr124 shRNA组,划痕实验评估细胞迁移,基质凝胶评估细胞小管形成能力。Western blot检测Gpr124、VEGFA、MMP9和β-catenin相对蛋白表达水平。结果相较于空白组,HRMEC在高糖组中显示出显著提升的细胞活力和增殖细胞数(P<0.01)。高糖环境下,Gpr124、VEGFA以及MMP9的表达水平也显著增加(P<0.01)。同时,在各个时间点,高糖对照组的迁移面积以及体外血管形成面积和管径长度均显著高于空白对照组(P<0.01)。然而,在敲低Gpr124的表达后,高糖+Gpr124 shRNA组的HRMEC在迁移和体外血管形成能力上相较于高糖+shRNA组有显著的降低(P<0.01),并且高糖+Gpr124 shRNA组相比于高糖+shRNA组VEGFA、MMP9以及β-catenin蛋白表达减少(P<0.01)。结论Gpr124能够调控高糖环境下HRMEC的增殖、迁移以及管形成能力,并且还可以抑制VEGFA和MMP9的过度表达,这一影响可能是通过调节Wnt/β-catenin经典通路来实现的。

间充质干细胞来源的外泌体对糖尿病视网膜病变的作用

外泌体是直径为40-100 nm的细胞外囊泡,其中含有蛋白质、miRNA等多种功能活性物质,并经由不同途径转运至细胞内。研究证实,外泌体能延缓糖尿病视网膜病变的病程进展,通过不同方式,包括直接调控和递送不同的miRNA、长链非编码RNA调控细胞增殖/凋亡因子、抗氧化调控因子、炎症因子、血管内皮生长因子等水平的变化,进而抑制高糖引起的视网膜炎症、新生血管形成、微血管损伤及血管渗漏等视网膜损伤。文章就外泌体的基本特征及其在糖尿病视网膜病变疾病中的研究进展进行系统综述。

玻璃体腔注射雷珠单抗对增殖性糖尿病性视网膜病变患者视力及血清GAS6、SDF-1及VEGF的影响

目的 探讨增殖性糖尿病视网膜病变(PDR)给予玻璃体腔注射雷珠单抗药物对患者视力以及血清人生长停滞特异性蛋白(GAS6)、人基质细胞衍生因子1(SDF-1)、血管内皮细胞生长因子(VEGF)影响。方法 纳入2022年1月至12月收治的PDR患者82例,按照随机数字表法分为观察组和对照组,每组41例。对照组采用玻璃体切割术(PPV)治疗,观察组采用联合玻璃体切割术(PPV)术前经玻璃体腔注射雷珠单抗治疗。对比2组的治疗效果,2组患者术前与术后1周的视力以及眼压水平,2组患者术前与术后1周血清GAS6、SDF-1、VEGF水平变化,2组术后并发症发生情况。结果 观察组治疗总有效率为95.12%高于对照组的78.05%(P<0.05)。2组患者术后1周的眼压、血清GAS6、SDF-1、VEGF水平均较术前降低,且观察组术后1周的上述指标水平低于对照组(P<0.05)。2组术后1周视力较术前升高,且观察组视力水平高于对照组(P<0.05)。观察组患者术后并发症总发生率为4.88%低于对照组的24.39%(P<0.05)。结论 应用玻璃体腔注射雷珠单抗辅助PPV治疗PDR,效果满意,可显著提高患者视力,降低眼压,降低血清GAS6、SDF-1、VEGF水平,且术后并发症发生率低,值得推广。