LncRNA XIST promotes neovascularization in diabetic retinopathy by regulating miR-101-3p/VEGFA

Rapid growth of residual tumors can occur as a result of their recurrence and progression. The present study aimed to investigate the expression of hypoxia inducible factor-2 subunit α (HIF-2α), vascular endothelial growth factor A (VEGFA), erythropoietin-producing hepatocellular A2 (EphA2) and angiogenesis in residual hepatocellular carcinoma (HCC), following treatment with high-intensity focused ultrasound (HIFU) ablation, in order to investigate the association between protein expression and tumor recurrence and growth. Athymic BALB/c (nu/nu) mice were subcutaneously inoculated with the HCC cell line HepG2, in order to create xenograft tumors. Approximately 30 days post-inoculation, eight mice were treated with HIFU, whereas eight mice received no treatment and acted as the control group. Residual tumor tissues were obtained from the experimental groups after one month. Levels of HIF-2α, VEGFA, EphA2 and cluster of differentiation 31 (CD31) expression was measured by immunohistochemical staining. CD31-positive vascular endothelial cells were counted to calculate microvascular density (MVD), and western blot analysis was performed to determine levels of HIF-2α, VEGFA, and EphA2 protein. It was found that the expression levels of HIF-2α, VEGFA, EphA2, and MVD proteins in residual HCC tissues were significantly higher than in the control group tissues (P<0.05). Tumor MVD was strongly correlated with VEGFA (R=0.957, P<0.01) and EphA2 (R=0.993, P<0.01) protein expression levels. Furthermore, there was a significant positive correlation between HIF-2α and EphA2 expression (R=0.991, P<0.01). The correlation between VEGFA and EphA2 expression was also positive (R=0.985, P<0.01). These data suggest that overexpression of HIF-2α, VEGFA and EphA2 is related to angiogenesis in residual HCC following HIFU ablation, potentially via their association with key mediators of recurrence.

Neovascularization plays a substantial role in the invasiveness and metastasis of gastric cancer. However, the molecular mechanism underlying the control of neovascularization of gastric cancer remains undefined. Both vascular endothelial growth factor a (VEGFa) and matrix metalloproteinases 2 (MMP2) are essential for neovascularization by promoting endothelial mitogenesis and permeability and by promoting extracellular matrix degradation, respectively. Therefore, we were prompted to examine whether VEGFa and MMP2 may affect expression of each other to coordinate the neovascularization process. We found strong positive correlation of VEGFa and MMP2 levels in the gastric patients. Moreover, patients with metastasis of the original cancer had significantly higher levels of VEGFa and MMP2. Thus, we used a human gastric cancer cell line, SNU-5, to examine whether expression of VEGFa and MMP2 may affect each other. We found that overexpression of VEGFa in SNU-5 cells increased expression of MMP2, while inhibition of VEGFa in SNU-5 cells decreased expression of MMP2. On the other hand, overexpression of MMP2 in SNU-5 cells increased expression of VEGFa, while inhibition of MMP2 in SNU-5 cells decreased expression of VEGFa. These data suggest that expression of VEGFa and MMP2 may activate each other to reinforce a promoting effect on neovascularization. We then analyzed how VEGFa expression affects MMP2 level. Application of a specific Akt inhibitor to VEGFa-overexpressing SNU-5 cells substantially abolished the effect of VEGFa on MMP2 activation, suggesting that VEGFa may increase expression of MMP2 via PI3K/Akt signaling pathway. Since anti-VEGFa is a well-established therapy for many cancers, our data suggest that anti-VEGFa may not only inhibit neovascularization by prohibiting VEGFa-dependent endothelial mitogenesis and permeability increase but also by downregulating MMP2 to abolish the extracellular matrix degradation in gastric cancer.

MicroRNA (miRNA or miR) expression profiles are altered in tissues under hypoxic-ischemic conditions. The expression of miR‑140 is downregulated >2-fold following hypoxic-ischemic brain damage, however, its role in angiogenesis subsequent to cerebral ischemia is not fully understood. The present study aimed to investigate the role of miR-140-5p in angiogenesis and the molecular mechanism mediated by vascular endothelial growth factorA (VEGFA) in an invitro model for brain ischemia. A rat middle cerebral artery occlusion (MCAO) model was constructed, and the results from reverse transcription-quantitative polymerase chain reaction and western blot analysis demonstrated that the expression levels of miR-140‑5p were significantly decreased, while the expression levels of VEGFA were significantly increased between12and48h in the rat cerebral following MCAO. Furthermore, human umbilical vein endothelial cells (HUVECs) were exposed to low oxygen conditions and it was demonstrated that hypoxia downregulated miR-140-5p and upregulated VEGFA expression levels. The miR-140-5p mimic was transfected into the normoxic and hypoxic HUVECs and3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, Transwell migration and tube formation assays were performed. The results indicated that miR‑140‑5p inhibited angiogenesis by decreasing cell proliferation, migration and tube formation. Additionally, in human embryonic kidney293cells, results from the luciferase reporter assay revealed that miR‑140‑5p directly targeted the3'untranslated region of VEGFA and that miR‑140‑5p regulated the protein expression of VEGFA. To further analyze this effect, a VEGFA‑pEGFP‑C1 plasmid was transfected into the normoxic and hypoxic HUVECs, and it was revealed that the inhibitory effect of miR‑140‑5p on angiogenesis was attenuated by the overexpression of VEGFA. In conclusion, to the best of our knowledge, the present study is the first to suggest that miR‑140‑5p exerts an inhibitory effect on angiogenesis in an invitro model of ischemia, and this effect is achieved partially by targeting VEGFA. The present study provided a novel biomarker for the treatment of cerebral ischemia.

Diabetic retinopathy (DR) is a leading cause of adult visual impairment and loss. This study aims to explore the effects of microRNA-9 (miR-9) on retinal neovascularization during DR by targeting the vascular endothelial growth factor A (VEGFA). DR rat models were successfully established. Retinal microvascular endothelial cells (RMECs) of DR rats were isolated and treated with miR-9 mimic, miR-9 inhibitor or small interfering RNA (siRNA)-VEGFA. The expressions of miR-9, VEGFA, and cluster of differentiation 31 (CD31) of the rats' tissues and cells were examined. The targeting relationship between miR-9 and VEGFA was testified. The tubule formation, the cell proliferation and the periodic distribution and apoptosis were evaluated after transfection. In the retinal tissues of DR rats, miR-9 expression decreased while the expression of VEGFA and CD31 increased. Notably, miR-9 targeted and inhibited VEGFA expression. In response to the treatment of miR-9 mimic and siRNA-VEGFA, a reduction was identified in CD31 expression, tubule formation, and proliferation of RMECs and cell ratio in the S phase, but an increase was observed in apoptosis rate of RMECs. The treatment of miR-9 inhibitor reversed the manifestations. Our study demonstrated that miR-9 could inhibit retinal neovascularization of DR and tubule formation, and promote apoptosis in RMECs by targeting VEGFA.

Sphingosine 1-phosphate (S1P) is a bioactive sphingolipid generated through sphingosine kinase1 (SPK1)-mediated phosphorylation of sphingosine. We show here that injury-induced S1P upregulation increases corneal neovascularization through stimulating S1PR3, a cognate receptor. since this response was suppressed in S1PR3-knockout mice. Furthermore, Cayman10444, a selective S1PR3 inhibitor, reduced this response in WT mice. Such reductions in neovascularization were associated with reduced vascular endothelial growth factor A (VEGF-A) mRNA expression levels in WT TKE2 corneal epithelial cells and macrophages treated with CAY10444 as well as macrophages isolated from S1PR3 KO mice. S1P increased tube-like vessel formation in human vascular endothelial cells (HUVEC) and human retinal microvascular endothelial cells (HRMECs) cells expressing S1PR3. In S1PR3 KO mice, TGFβ1-induced increases in αSMA gene expression levels were suppressed relative to those in the WT counterparts. In S1PR3 deficient macrophages, VEGF-A expression levels were lower than in WT macrophages. Transforming growth factor β1(TGFβ1) upregulated SPK1 expression levels in ocular fibroblasts and TKE2 corneal epithelial cells. CAY10444 blocked S1P-induced increases in VEGF-A mRNA expression levels in TKE2 corneal epithelial cells. Endogenous S1P signaling upregulated VEGF-A and VE-cadherin mRNA expression levels in HUVEC. Unlike in TKE2 cells, SIS3 failed to block TGFβ1-induced VEGF-A upregulation in ocular fibroblasts. Taken together, these results indicate that injury-induced TGFβ1 upregulation increases S1P generation through increases in SPK1 activity. The rise in S1P formation stimulates the S1PR3-linked signaling pathway, which in turn increases VEGF-A expression levels and angiogenesis in mouse corneas.Injury-induced transforming growth factor β1 increases sphingosine 1-phosphate (S1P) generation by upregulating in sphingosine kinase 1 activity. The high levels of S1P formation stimulate the S1PR3-linked signaling pathway, which in turn increases vascular endothelial growth factor-A expression levels and angiogenesis in mouse corneas.

Endometriosis is identified as presence of the endometrium outside the uterine cavity. Retrograde menstruation contributes to the endometrial tissue implantation and the establishment of endometriotic lesions at ectopic sites. It has been suggested that the endometriotic lesions are rich in angiogenic growth factors, while they have an essential role in survival and invasion of these cells. We investigated regulation of microRNA-93 (miR-93) and its involvement with vascular endothelial growth factor A (VEGFA) and matrix metalloproteinase (MMP) 3 expression in women with endometriosis. This was a cross-sectional study at Central Surgical Installation, Dr. Cipto Mangunkusumo General Hospital, Jakarta, Indonesia, between October 2020 and November 2021. Eutopic and ectopic endometrial tissues were collected from 30 subjects with laparoscopically-confirmed endometriotic women. Normal endometrial cells of non-endometriosis women served as controls. Total RNA was isolated from all samples and a quantitative reverse-transcription polymerase chain reaction (qRT-PCR) was used to analyze the expression of miR-93, VEGFA and MMP. There was no significant difference in the expression levels of VEGFA (2.14 ± 0.50, P=0.719) and MMP3 (2.99 ± 0.42, P=0.583) between endometriotic lesions of endometriosis women and the healthy endometrium. Expression of miR-93 was significantly lower in the eutopic endometrium (16.7 fold) and ectopic endometriotic lesion (20 fold) compared to the normal endometrium (P<0.001). Furthermore, we also observed a significant correlation between miR-93, VEGFA expression in eutopic endometrium obtained from women with endometriosis (r=-0.544, P=0.029). Expression of the miR-93 was also negatively correlated with MMP3 expression in both eutopic (r=-0.412, P=0.01) and ectopic (r=-0.539, P=0.03) endometrial cells of women with endometriosis. VEGFA and MMP3 expression levels trended to be increased in both eutopic and ectopic endometrial tissues of endometriosis women, while down-regulation of miR-93 might be involved in the alteration of VEGFA and MMP3 in endometriosis.

BackgroundPreviously, we have screened 59 differentially expressed miRNAs and 419 mRNAs in the glioblastoma samples that have been compared to the peritumoral tissues using bioinformatics analyses, which included miRNA-383-5p and vascular endothelial growth factor A (VEGFA). miRNA-383-5p and VEGFA/Akt/mTOR pathway play important regulatory roles in the malignant biological behavior of glioma.MethodsGlioma cell lines, U87 and U251, were collected for in vitro experiments. miRNA-383-5p and VEGFA expression levels were detected with qRT-PCR and WB. The protein expressions of Akt, mTOR, and VEGFR in U87 and U251 were detected with WB. The effect of miRNA-383-5p on the VEGFA activity was verified by dual-luciferase reporter assay. CCK-8 was used to examine the U87 and U251 cells’ inhibition. Flow cytometry and transwell assays were used to detect cell apoptosis and invasion, respectively.ResultsOur research data indicated overexpression of miRNA-383-5p to suppress malignant biological behavior, which was manifested as promoting the apoptosis of U87 and U251 cells and inhibiting invasion, proliferation, and metastasis. VEGFA is one of the downstream target genes of miRNA-383-5p. miRNA-383-5p could inhibit the expression of VEGFA and Akt/mTOR signaling pathways. Overexpression of VEGFA can reverse the inhibitory effect of miRNA-383-5p and reactivate the Akt/mTOR signaling pathway.ConclusionOur results indicate that miRNA-383-5p functions as an anti-oncogene by inhibiting the VEGFA/Akt/mTOR signaling pathway in glioma cells. These data provide potential therapeutic targets for glioblastoma.

The present study explored the effect of miR-200b on the development of diabetic retinopathy (DR) by targeting vascular endothelial growth factor A (VEGFA) gene. The study populations consisted of 255 DR patients (case group) and 253 healthy people (control group), while the expressions of miR-200b and VEGFA mRNA were detected by quantitative real-time PCR (qRT-PCR). Bioinformatics software and dual-luciferase reporter assay were used to confirm VEGFA as a target gene of miR-200b. Also, a total of 70 Wistar male rats were selected and randomly assigned into blank, normal control (NC), miR-200b mimics, miR-200b inhibitors, miR-200b inhibitors + silencing vascular endothelial growth factor A (siVEGFA), and siVEGFA groups (n=10/group) respectively. Streptozotocin (STZ)-induced rat models of DR were successfully established. VEGFA, transforming growth factor-β1 (TGF-β1), hepatocyte growth factor (HGF), and pigment epithelium-derived factor (PEDF) were detected using qRT-PCR and Western blotting. In comparison with the control group, the case group showed lower expression of miR-200b but higher expression of VEGFA mRNA. VEGFA was confirmed as a target gene of miR-200b. Rats in the miR-200b mimics and siVEGFA groups exhibited higher expression of PEDF mRNA and protein but lower expressions of VEGFA, TGF-β1, HGF protein, and mRNA than the NC group. There was no remarkable difference in expressions of PEDF, VEGFA, TGF-β1, HGF protein, and mRNA between the miR-200b inhibitors + siVEGFA and NC groups. In conclusion, the present study demonstrated that miR-200b might alleviate DR development by down-regulating its target gene VEGFA.

VEGF-A Links Angiogenesis and Inflammation in Inflammatory Bowel Disease Pathogenesis

High levels of vascular endothelial growth factor A (VEGFA) seem to herald a worse prognosis in mycosis fungoides (MF). In this study, we aimed to characterize more clearly VEGFA gene and protein expression in MF. First, we compared VEGFA mRNA levels in MF and in normal T lymphocyte samples; significantly higher VEGFA levels were found in MF. We then studied VEGFA expression in different normal T cell subsets, focusing on CD4(+) , CD8(+) , resting and activated T lymphocytes. We applied the gene signatures of the normal T cell subsets to MF samples and found that activated T lymphocytes represented the closest normal counterpart of the tumour. However, VEGFA mRNA levels were significantly higher in MF than in activated normal T cells, suggesting that VEGFA overexpression in MF represents an attribute acquired during neoplastic transformation: no significant VEGFA expression differences were recorded between early and advanced stages. Gene expression profile results were supported by immunohistochemistry in routine sections from 27 MF cases. For the first time, we demonstrate VEGFA expression in MF cells, suggesting that the VEGF pathway may be implicated in MF pathogenesis and can represent a novel therapeutic target.

Objective: To evaluate the effects of vascular endothelial growth factor A (VEGFA) and vascular endothelial growth factor receptor 2 (VEGFR2) on disease-free survival (DFS) of patients with lung adenocarcinoma receiving surgery. Methods: Immunohistochemistry (IHC) was performed to detect the expressions of VEGFA and VEGFR2 proteins in adenocarcinoma tissues from 114 patients after surgery. The information on clinical characteristics including gender, age, smoking status, tumor size, number of positive lymph nodes (PLNs), clinical stage and treatment after surgery was collected, and the associations of VEGFA and VEGFR2 expressions with the clinical characteristics were analyzed. The COX proportional hazards regression model was used to identify the independent prognostic factors for DFS. Results: The IHC result showed that the positive rates of VEGFA and VEGFR2 expressions in adenocarcinoma tissue samples were 46.49% (53/114) and 46.49% (53/114), respectively. There was no evidence indicating that VEGFA expression was significantly associated with the clinical characteristics of patients with lung adenocarcinoma, but VEGFR2 expression was significantly correlated with the tumor size (P = 0.03). COX proportional hazards regression model revealed that VEGFA and VEGFR2 expressions had no significant effects on patients’ DFS; the tumor size > 4 cm (relative risk: 2.29; 95% confidence interval: 1.32-3.97; P = 0.003) and the number of PLNs ≥ 2 (relative risk: 2.15; 95% confidence interval: 1.27-3.64; P = 0.005) were independent factors to predict DFS of patients with lung adenocarcinoma after surgery. Conclusion: For patients with lung adenocarcinoma receiving surgery, VEGFA and VEGFR2 expressions have no significant correlation with DFS; the tumor size > 4 cm and the number of PLNs ≥ 2 may be the independent factors affecting DFS. DOI:10.3781/j.issn.1000-7431.2017.33.282

The present study aimed to investigate the effect of diosgenin on mammalian target of rapamycin(mTOR), fatty acid synthase(FASN), hypoxia inducible factor-1α(HIF-1α), and vascular endothelial growth factor A(VEGFA) expression in liver tissues of rats with non-alcoholic fatty liver disease(NAFLD) and explore the mechanism of diosgenin on lipogenesis and inflammation in NAFLD. Forty male SD rats were divided into a normal group(n=8) fed on the normal diet and an experimental group(n=32) fed on the high-fat diet(HFD) for the induction of the NAFLD model. After modeling, the rats in the experimental group were randomly divided into an HFD group, a low-dose diosgenin group(150 mg·kg~(-1)·d~(-1)), a high-dose diosgenin group(300 mg·kg~(-1)·d~(-1)), and a simvastatin group(4 mg·kg~(-1)·d~(-1)), with eight rats in each group. The drugs were continuously given by gavage for eight weeks. The levels of triglyceride(TG), total cholesterol(TC), low-density lipoprotein cholesterol(LDL-C), alanine transaminase(ALT), and aspartate transaminase(AST) in the serum were detected by the biochemical method. The content of TG and TC in the liver was detected by the enzyme method. Enzyme-linked immunosorbent assay(ELISA) was used to measure interleukin 1β(IL-1β) and tumor necrosis factor α(TNF-α) in the serum. Lipid accumulation in the liver was detected by oil red O staining. Pathological changes of liver tissues were detected by hematoxylin-eosin(HE) staining. The mRNA and protein expression levels of mTOR, FASN, HIF-1α, and VEGFA in the liver of rats were detected by real-time fluorescence-based quantitative polymerase chain reaction(PCR) and Western blot, respectively. Compared with the normal group, the HFD group showed elevated body weight and levels of TG, TC, LDL-C, ALT, AST, IL-1β, and TNF-α(P&lt;0.01), increased lipid accumulation in the liver(P&lt;0.01), obvious liver steatosis, up-regulated mRNA expression levels of mTOR, FASN, HIF-1α, and VEGFA(P&lt;0.01), and increased protein expression levels of p-mTOR, FASN, HIF-1α, and VEGFA(P&lt;0.01). Compared with the HFD group, the groups with drug treatment showed lowered body weight and levels of TG, TC, LDL-C, ALT, AST, IL-1β, and TNF-α(P&lt;0.05, P&lt;0.01), reduced lipid accumulation in the liver(P&lt;0.01), improved liver steatosis, decreased mRNA expression levels of mTOR, FASN, HIF-1α, and VEGFA(P&lt;0.05, P&lt;0.01), and declining protein expression levels of p-mTOR, FASN, HIF-1α, and VEGFA(P&lt;0.01). The therapeutic effect of the high-dose diosgenin group was superior to that of the low-dose diosgenin group and the simvastatin group. Diosgenin may reduce liver lipid synthesis and inflammation and potentiate by down-regulating the mTOR, FASN, HIF-1α, and VEGFA expression, playing an active role in preventing and treating NAFLD.

This study aims to investigate whether tetramethylpyrazine(TMP) can stimulate angiogenesis in cerebral microvascular endothelial cells and alleviate cerebral ischemic stroke(CIS) and to explore the underlying mechanisms. In the animal study, adult Sprague-Dawley rats(n=15) were assigned into sham surgery(sham), middle cerebral artery occlusion/reperfusion(MCAO/R), and MCAO/R+TMP(intraperitoneal injection of 20 mg·kg~(-1)) groups. The neurological function was evaluated by the Z-Longa method. The cerebral infarction volume was detected by TTC staining. Enzyme-linked immunosorbent assay(ELISA) was employed to detect the expression of vascular endothelial growth factor(VEGF), angiopoietin(Ang), and platelet-derived growth factor(PDGF). Immunofluorescence staining was employed to detect Ki67 and the expression of vascular endothelial growth factor A(VEGFA) and slient information regulator 1(SIRT1). Western blot was employed to determine the expression levels of VEGFA, SIRT1, angiopoietin-2(Ang-2), and platelet-derived growth factor B(PDGFB). In the cell study, mouse brain-derived endothelial cells(Bend.3) were cultured, and the optimal concentration of TMP was determined. Then, VEGF, Ang, and PDGF were detected by ELISA after the addition of cabozantinib. Western blot was employed to measure the expression of VEGFA, Ang-2, and PDGFB. Immunofluorescence staining was used to detect CD31, CD34, and Ki67, and the proliferation, migration, and tube formation ability of Bend.3 cells were observed in vitro. Western blot and immunofluorescence staining were performed to measure the expression of SIRT1 and VEGFA after addition of the SIRT1-specific inhibitor selisistat(EX-527). The results showed that compared with the sham group, the MCAO/R group had severe neurological function damage, increased infarction volume, up-regulated expression of VEGF, VEGFA, Ang, Ang-2, PDGF, and PDGFB, and down-regulated expression of Ki67 and SIRT1(P&lt;0.01). Compared with the MCAO/R group, the MCAO/R+TMP group presented alleviated neurological function damage, reduced infarction volume, and activated expression of VEGF, VEGFA, Ang, Ang-2, PDGF, PDGFB, Ki67, and SIRT1(P&lt;0.01). The cell experiments showed that compared with the normal group, Bend.3 cells were activated by oxygen glucose deprivation/reoxygenation(OGD/R) treatment(P&lt;0.05, P&lt;0.01). Compared with the OGD/R group, the OGD/R+TMP group upregulated the expression levels of VEGF, VEGFA, Ang, Ang-2, PDGF, PDGFB, SIRT1, Ki67, CD31, and CD34, enhanced the angiogenic ability of Bend.3 cells without being inhibited by BMS or EX-527(P&lt;0.05, P&lt;0.01, P&lt;0.001). The results suggest that TMP can activate the SIRT1/VEGFA signaling pathway to stimulate angiogenesis and alleviate CIS injury.

Vascular endothelial growth factor A (VEGFA) plays a critical role as a potent angiogenesis factor and is highly expressed in hepatocellular carcinoma (HCC). Although the expression of VEGFA has been strongly linked to the aggressive nature of HCC, the specific posttranscriptional modifications that might contribute to VEGFA expression and HCC angiogenesis are not yet well understood. In this study, we aimed to investigate the epitranscriptome regulation of VEGFA in HCC. A comprehensive analysis integrating MeRIP-seq, RNA-seq, and crosslinking-immunprecipitation-seq data revealed that VEGFA was hypermethylated in HCC and identified the potential m6A regulators of VEGFA including a m6A methyltransferase complex component RBM15 and the two readers, YTHDF2 and IGF2BP3. Through rigorous cell and molecular biology experiments, RBM15 was validated as a key component of methyltransferase complex responsible for m6A methylation of VEGFA, which was subsequently recognized and stabilized by IGF2BP3 and YTHDF2, leading to enhanced VEGFA expression and VEGFA-related functions such as human umbilical vascular endothelial cells (HUVEC) migration and tube formation. In the HCC xenograft model, knockdown of RBM15, IGF2BP3, or YTHDF2 resulted in reduced expression of VEGFA, accompanied by significant inhibition of tumor growth closely associated with VEGFA expression and angiogenesis. Furthermore, our analysis of HCC clinical samples identified positive correlations between the expression levels of VEGFA and the regulators RBM15, IGF2BP3, and YTHDF2. Collectively, these findings offer novel insights into the posttranscriptional modulation of VEGFA and provide potential avenues for alternative approaches to antiangiogenesis therapy targeting VEGFA.

To investigate the role of microRNA-15b in diabetic retinopathy and its underlying mechanism. Diabetes rat model was established by streptozotocin injection. The mRNA expression of microRNA-15b in retinal capillary endothelial cells and pericytes of diabetic rats was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The mRNA and protein expressions of vascular endothelial growth factor A (VEGFA) were detected by qRT-PCR and Western blot, respectively. MicroRNA-15b mimics or inhibitor were transfected into retinal capillary endothelial cells and pericytes of diabetic rats, respectively. The mRNA expressions of microRNA-15b and VEGFA were detected by qRT-PCR. Cell counting kit-8 (CCK-8) assay was used to detect the proliferation of capillary endothelial cells and pericytes. Dual-Luciferase reporter gene assay was conducted to verify the binding condition of microRNA-15b and VEGFA. RNA immunoprecipitation (RIP) assay was performed to determine whether microRNA-15b could bind to AGO2. Rescue experiments were finally carried out by detecting the proliferation of retinal capillary endothelial cells and pericytes after downregulation or overexpression of microRNA-15b and VEGFA. The expression of microRNA-15b decreased, whereas VEGFA expression increased in retinal capillary endothelial cells and pericytes of diabetic rats. High expression of microRNA-15b in retinal capillary endothelial cells and pericytes resulted in VEGFA down-regulation and decreased proliferation. RIP assay results indicated that microRNA-15b could interact with AGO2. Additionally, Dual-Luciferase reporter gene assay showed that VEGFA is a direct target gene of microRNA-15b. VEGFA overexpression could reverse the inhibited proliferation of retinal capillary endothelial cells and pericytes induced by microRNA-15b overexpression. Similarly, VEGFA knockdown could reverse the effect of the low expression of microRNA-15b on the proliferation of retinal capillary endothelial cells and pericytes. Low expression of microRNA-15b in retinal capillary endothelial cells and pericytes of diabetic rats promotes the development of diabetic retinopathy by up-regulating VEGFA.