Proliferation Of Retinal Endothelial Cells Research Articles

TRNA-derived fragment tRF-30 propels diabetes-induced retinal microvascular complications by regulating STAT3 signaling.

Transfer RNA-derived fragments (tRFs) represent a novel class of non-coding RNA transcripts that possess specific biological functions. However, the involvement of tRFs in retinal microvascular diseases remains poorly understood. In this study, we aimed to reveal whether modulation of tRF-30 expression could attenuate pathological retinal neovascular diseases. Our findings demonstrate a significant upregulation of tRF-30 expression levels in both in vivo models of diabetic retinopathy (DR) and in vitro endothelial sprouting models. Conversely, inhibition of tRF-30 expression suppressed the formation of abnormal neovascularization in the retina in vivo, while reducing the proliferation and migration activity of retinal vascular endothelial cells in vitro. We also found that tRF-30 modulates retinal neovascularization through the tRF-30/TRIB3/signal transducer and activated transcription 3 signaling pathway. Furthermore, we validated a significant upregulation of tRF-30 expression levels in the vitreous humor of DR patients, with high levels of both validity and specificity in diagnostic testing. Collectively, our findings highlight a pro-angiogenic role for tRF-30 in DR. Intervening in the tRF-30 signaling pathway may represent a promising prevention and treatment strategy for retinal angiogenesis.

Role of Gpr124 in the Migration and Proliferation of Retinal Microvascular Endothelial Cells and Microangiopathies in Diabetic Retinopathy.

Retinal microangiopathies, such as neovascularization and preretinal and vitreous hemorrhages, are the primary pathological features of diabetic retinopathy (DR). These conditions can worsen visual impairment and may result in blindness. Furthermore, multiple metabolic pathways are associated with microangiopathy in DR. However, the specific underlying pathological mechanisms remain unclear. Several studies have demonstrated the important role of G protein-coupled receptor 124 (Gpr124) in cerebral vascular endothelial cells, but its effect on the retinal endothelium has not been elucidated. In this study, we found that Gpr124 is expressed in both pathological retinal fibrous vascular membranes of DR patients and retinal blood vessels of mice, with elevated protein expression specifically observed in the retinas of DR model mice. Furthermore, Gpr124 expression was elevated after high-glucose treatment of human retinal microvascular endothelial cells (HRMECs). Inhibition of Gpr124 expression affected the high glucose-induced proliferation, migration, and tube-forming ability of HRMECs. We concluded that Gpr124 expression was upregulated in DR and promoted HRMECs angiogenesis in a high-glucose environment. This finding may help to elucidate the pathogenesis of DR and provide a critical research basis for identifying effective treatments.

Nerolidol Alleviates Oxidative Stress and Inflammation in Diabetic Retinopathy Mediated by High Glucose Through Ameliorating Nrf2/HO-1 Pathway

Background Diabetic retinopathy (DR) is the foremost microvascular problem that causes drastic visual impairment in diabetes patients. Hyperglycemia-triggered reaction cascade of inflammation and oxidative stress constitute the DR pathogenesis. The existing treatment options are not completely satisfactory. Materials and Methods We investigated the cell viability by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay, inflammatory mediators, lactate dehydrogenase (LDH), superoxide dismutase, glutathione, and malonaldehyde (MDA) levels by ELISA and qRT-PCR assay, protein expression of Nrf2 and heme oxygenase-1 (HO-1) by western blotting assay were analyzed. Results According to our research, nerolidol (NRD) increases the proliferation and antioxidant activity of human retinal endothelial cells (HRECs) by inducing Nrf2/HO-1 signaling, while attenuating MDA, an oxidative stress marker, LDH, and inflammatory mediators. These outcomes suggest that a substantial reaction of inflammation and oxidative stress injury happened in DR, which might be correlated to the instigation of the signaling Nrf2/HO-1. Conclusion NRD effectively suppresses oxidative stress and inflammation in HG-induced HRECs. The primary mechanism of NRD on DR may be linked to the activation of the Nrf2/HO-1 pathway and may give a useful medicine for DR treatment.

Lysyl oxidase-mediated elastin upregulation promotes the proliferation and migration of human retinal endothelial cells.

Proliferative diabetic retinopathy (PDR) is a major cause of irreversible blindness in the working age population. The dysfunction of retinal vascular endothelial cells (RVECs) is the primary cause of PDR. Extracellular matrix (ECM) accumulation promotes intracellular signaling required for RVEC proliferation, migration, survival, and tube morphogenesis. This study aimed to investigate the role of lysyl oxidase (LOX) in the cellular function of RVECs and PDR pathogenesis and to identify the underlying mechanisms. Protein expression was determined with western blot. The interaction between LOX and elastin (ELN) was detected using a co-immunoprecipitation (Co-IP) assay, and the Cell Counting Kit-8 (CCK-8) assay evaluated cell viability. A colony formation assay was employed to assess the proliferation of human RVECs (hRVECs), and a transwell assay to determine their migration ability. Streptozotocin was used to establish PDR in mice in vivo. A histological analysis was conducted using hematoxylin and eosin (H&E) staining. The results showed that LOX was overexpressed in PDR patients. The LOX knockdown suppressed ECM formation and hRVEC proliferation and migration. Additionally, LOX upregulated ELN expression. However, overexpressed ELN promoted hRVEC proliferation and migration. In vivo experiments showed that curcumin-mediated LOX deficiency restored retinal tissue structure. The LOX-knockdown suppressed ECM formation and hRVEC proliferation and migration by inactivating ELN. Therefore, LOX/ELN signaling may be a potential PDR biomarker.

Effects of tumor necrosis factor-α and interleukin-1β on human retinal endothelial cells

Uveitis, or intraocular inflammation, is a potentially blinding condition that mostly affects the working-age population. The cytokines, tumor necrosis factor (TNF)-α and interleukin (IL)-1β, play a role in the pathogenesis of non-infectious uveitis and have been linked to the breakdown of the inner blood-retinal barrier, composed mainly of retinal endothelial cells, leading to macular oedema and vascular leakage. However, the effects of TNF-α and IL-1β on human retinal endothelial function are not fully understood. In this work, we investigated the impact of TNF-α and IL-1β on several aspects of human retinal endothelial cell biology. Through a real-time biosensor, the impact of TNF-α and IL-1β on formation of a retinal endothelial cell barrier was analyzed. Changes in junctional components were assessed via RT-qPCR and immunolabelling. Cell survival, necrosis and apoptosis were appraised via cell proliferation and flow cytometric studies. Tumor necrosis factor-α and IL-1β impaired the electrical resistance of the retinal endothelial cell barrier, while the addition of a potentially barrier-impairing cytokine, IL-6, did not enhance the effect of TNF-α and IL-1β. Level of the gene transcript encoding zonula occludens (ZO)-1 was diminished, while ZO-1 protein configuration was changed by TNF-α and IL-1β. Both cytokines affected human retinal endothelial cell proliferation and viability, while only TNF-α increased rates of necrosis. These results indicate that TNF-α and IL-1β are important drivers of retinal endothelial dysfunction in non-infectious uveitis, suggesting that targeting these cytokines is critical when treating complications of uveitis, such as macular oedema and vascular leakage.

Aberrant SUMO2/3 modification of RUNX1 upon SENP1 inhibition is linked to the development of diabetic retinopathy in mice

Our previous report established that RUNX family transcription factor 1 (RUNX1) promotes proliferation of mouse retinal microvascular endothelial cells (mRMECs) and exacerbates diabetic retinopathy (DR). However, the mechanism behind the upregulation of RUNX1 remains unclear. This study aims to investigate the possible correlation between histone SUMOylation and RUNX1 in DR, as well as the involved molecules. A mouse model of diabetes was induced by streptozotocin (STZ). These mice had increased retinal thickness and elevated production of inflammatory cytokines. Additionally, they showed elevated levels of SUMO1 and SUMO2/3, but reduced levels of SUMO specific peptidase 1 (SENP1) in retinal tissues. Co-immunoprecipitation and Western blot assays revealed that the RUNX1 protein was primarily modified by SUMO2/3, and SENP1 inhibited SUMO2/3 modification, thereby reducing RUNX1 expression. Overexpression of SENP1 alleviated symptoms in mice and alleviated inflammation. In vitro experiments demonstrated that the SENP1 overexpression suppressed the proliferation, migration, and angiogenesis of high-glucose-induced mRMECs. However, further overexpression of RUNX1 counteracted the alleviating effects of SENP1 both in vivo and in vitro. In conclusion, this study demonstrates that the downregulation of SENP1 in DR leads to SUMO2/3-dependent activation of RUNX1. This activation promotes proliferation of mRMECs and exacerbates DR symptoms in mice.

BIBF1120 Protects against Diabetic Retinopathy through Neovascularization-Related Molecules and the MAPK Signaling Pathway.

Diabetic retinopathy (DR) is one of the microvascular complications of diabetes mellitus and a major pathological feature of neovascular DR. These patients potentially experience vision impairment and blindness. Platelet-derived growth factor receptor β (PDGFRβ), fibroblast growth factor receptor 1 (FGFR1), and vascular endothelial growth factor receptor 2 (VEGFR2) are implicated in the DR pathogenesis. Nintedanib (BIBF1120) is an oral selective dual receptor tyrosine kinase (RTK) inhibitor of VEGFR2, FGFR1, and PDGFRβ. In this study, intravitreal injection of BIBF1120 blocked the phosphorylation of VEGFR2, FGFR1, PDGFRβ, and MAPK signaling pathway proteins in a streptozotocin (STZ)-induced diabetic retinopathy mouse model. In in vitro cell experiments, BIBF1120 did not change cellular activity under normal conditions, while it further suppressed the tube formation, migration, and proliferation of high glucose-induced human retinal microvascular endothelial cells (HRMECs). Additionally, BIBF1120 blocked the phosphorylation of p38, JNK, and ERK1/2 in high glucose-treating HRMECs. Our results indicate that the BIBF1120 treatment can be a novel potential drug to protect against DR.

Long Noncoding RNA PPT2-EGFL8 Regulates Pathological Retinal Neovascularization in PDR by Functioning as a Competing Endogenous RNA.

Diabetic retinopathy (DR) is a common complication in patients with diabetes, and proliferative DR (PDR) has become an important cause of blindness; however, the mechanisms involved have not been fully elucidated. miRNAs and long noncoding RNAs can play an important role in DR, and they can accurately regulate the expression of target genes through a new regulatory model: competing endogenous RNAs. We isolated total RNA of extracellular vesicles (EVs) in the serum of healthy individuals and individuals with diabetes without DR, non-PDR, or PDR, and performed deep sequencing. We found aberrantly low expression of PPT2-EGFL8 and significantly increased level of miR-423-5p. PPT2-EGFL8 adsorbs miR-423-5p as a molecular sponge and inhibits hypoxia-induced human retinal microvascular endothelial cells proliferation. In an oxygen-induced retinopathy (OIR) model and a streptozotocin-induced diabetes model, Egfl8-overexpression treatment reduces diabetes-related reactive gliosis, inflammation, and acellular capillaries and attenuates the development of pathological neovascularization. In addition, PPT2-EGFL8 targeting miR-423-5p plays an important role in hypoxia-induced peroxisome proliferator-activated receptor-β/δ (PPARD)/angiopoietin-like 4 (ANGPTL4) signaling activation, especially the expression of the C-terminal ANGPTL4 fragment. Finally, ANGPTL4 significantly induces retinal vessel breakage in the inner limiting membrane and facilitates retinal vessel sprouting into the vitreous in the OIR mice. Thus, either new biomarkers or new therapeutic targets may be identified with translation of these findings.

The Effect of Thyroxin on the Biological Effects of High Glucose-Induced Human Retinal Endothelial Cells and B-Cell Lymphoma 2/Bcl-2 Associated X

This study intends to assess the biological effect of TTR on human retinal endothelial cells under high glucose. Cells were assigned into normal group, high glucose (HG) group and TTR intervention group followed by analysis of cell biological activity and protein expression. The retinal endothelial cell proliferation rate was significantly promoted in HG group (P < 0.05) and inhibited in intervention group (P < 0.05). The HG group had significantly higher cell migration number than normal group (P < 0.05). However, migrated cell number in intervention group was reduced significantly (P < 0.05). In addition, high glucose also significantly enhanced the invasion of retinal endothelial cells (P < 0.05), which was inhibited after TTR intervention (P < 0.05). Moreover, Bcl-2 protein was significantly downregulated and Bax was upregulated in HG group compared to normal group (P < 0.05). Interestingly, their levels were normalized after TTR intervention without difference compared to their levels in normal group (P < 0.05). Consistently, the mRNA level of Bcl-2 and Bax showed similar expression profiles to the protein expression in different groups (P < 0.05). In conclusion, TTR can inhibit the retinal endothelial cell proliferation, migration and invasion ability and regulate Bcl-2/Bax expression.

IL-17A Enhances Retinal Neovascularization.

Retinal neovascularization occurs in proliferative diabetic retinopathy, neovascular glaucoma, and age-related macular degeneration. This type of retinal pathology normally occurs in the later stages of these ocular diseases and is a prevalent cause of vision loss. Previously, we determined that Interleukin (IL)-17A plays a pivotal role in the onset and progression of non-proliferative diabetic retinopathy in diabetic mice. Unfortunately, none of our diabetic murine models progress to proliferative diabetic retinopathy. Hence, the role of IL-17A in vascular angiogenesis, neovascularization, and the onset of proliferative diabetic retinopathy was unclear. In the current study, we determined that diabetes-mediated IL-17A enhances vascular endothelial growth factor (VEGF) production in the retina, Muller glia, and retinal endothelial cells. Further, we determined that IL-17A can initiate retinal endothelial cell proliferation and can enhance VEGF-dependent vascular angiogenesis. Finally, by utilizing the oxygen induced retinopathy model, we determined that IL-17A enhances retinal neovascularization. Collectively, the results of this study provide evidence that IL-17A plays a pivotal role in vascular proliferation in the retina. Hence, IL-17A could be a potentially novel therapeutic target for retinal neovascularization, which can cause blindness in multiple ocular diseases.

Hippo/YAP signaling pathway: a new therapeutic target for diabetes mellitus and vascular complications.

Diabetic angiopathy, which includes diabetic kidney disease (DKD), cardio-cerebrovascular disease, and diabetic retinopathy (DR) among other diseases, is one of the most common complications affecting diabetic patients. Among these, DKD, which is a major cause of morbidity and mortality, affects about 40% of diabetic patients. Similarly, DR involves retinal neovascularization and neurodegeneration as a result of chronic hyperglycemia and is the main cause of visual impairment and blindness. In addition, inflammation also promotes atherosclerosis and diabetes, with atherosclerosis-related cardiovascular diseases being often a main cause of disability or death in diabetic patients. Given that vascular diseases caused by diabetes negatively impact human health, it is therefore important to identify appropriate treatments. In this context, some studies have found that the Hippo/Yes-associated protein (YAP) pathway is a highly evolutionarily conserved protein kinase signal pathway that regulates organ growth and size through its effector signaling pathway Transcriptional co-Activator with PDZ-binding motif (TAZ) and its YAP. YAP is a key factor in the Hippo pathway. The activation of YAP regulates gluconeogenesis, thereby regulating glucose tolerance levels; silencing the YAP gene thereby prevents the formation of glomerular fibrosis. YAP can combine with TEA domain family members to regulate the proliferation and migration of retinal vascular endothelial cells (ECs), so YAP plays a prominent role in the formation and pathology of retinal vessels. In addition, YAP/TAZ activation and translocation to the nucleus promote endothelial inflammation and monocyte-EC attachment, which can increase diabetes-induced cardiovascular atherosclerosis. Hippo/YAP signaling pathway provides a potential therapeutic target for diabetic angiopathy, which can prevent the progression of diabetes to DR and improve renal fibrosis and cardio-vascular atherosclerosis.

PGF2α facilitates pathological retinal angiogenesis by modulating endothelial FOS-driven ELR+ CXC chemokine expression.

The pathological retinal angiogenesis often causes blindness. Current anti-angiogenic therapy for proliferative retinopathy targets the vascular endothelial growth factor (VEGF), but many patients do not radically benefit from this therapy. Herein, we report that circulating prostaglandin (PG) F2α metabolites were increased in type 2 diabetic patients with proliferative retinopathy, and the PGF2α receptor (Ptgfr) was upregulated in retinal endothelial cells (ECs) from a mouse model of oxygen-induced retinopathy (OIR). Further, disruption of the PTGFR receptor in ECs attenuated OIR in mice. PGF2α promoted the proliferation and tube formation of human retinal microvascular endothelial cells (HRMECs) via the release of ELR+ CXC chemokines, such as CXCL8 and CXCL2. Mechanistically, the PGF2α /PTGFR axis potentiated ELR+ CXC chemokine expression in HRMECs through the Gq /CAMK2G/p38/ELK-1/FOS pathway. Upregulated FOS-mediated ELR+ CXC chemokine expression was observed in retinal ECs from PDR patients. Moreover, treatment with PTGFR inhibitor lessened the development of OIR in mice in a CXCR2-dependent manner. Therefore, inhibition of PTGFR may represent a new avenue for the treatment of retinal neovascularization, particularly in PDR.

Ginsenoside Rg1 Inhibits High Glucose-Induced Proliferation, Migration, and Angiogenesis in Retinal Endothelial Cells by Regulating the lncRNA SNHG7/miR-2116-5p/SIRT3 Axis.

Diabetic retinopathy (DR), including retinal angiogenesis and endothelial cell proliferation and migration, is a serious complication in diabetic patients. It has been reported that ginsenoside Rg1 can prevent retinal damage. However, the mechanism by which Rg1 prevents retinal damage is unknown. Therefore, the aim of the present study was to investigate the mechanism by which Rg1 inhibits high glucose-induced complications through the regulation of the lncRNA SNHG7/miR-2116-5p/SIRT3 axis. Under high glucose (HG) conditions, human retinal endothelial cells (HRECs) were cultured to simulate a DR environment, and Rg1 was added after 48 h. Negative control (NC), miR-2116-5p mimic, si-SNHG7, pc-DNA SIRT3, and miR-2116-5p inhibitor were transfected into HRECs, and CCK-8 assay was used to detect the cell viability. Angiogenesis and transwell assays were used to evaluate angiogenesis and cell migration, respectively. qRT-PCR and Western blot were used to detect the expression of related genes and proteins. Luciferase reporter assays and bioinformatics were used to analyze the target binding sites of miR-2116-5p to lncRNA SNHG7 and SIRT3. The proliferation, migration and angiogenesis of HRECs were induced by HG. As expected, HG upregulated miR-2116-5p and VEGF expression but downregulated lncRNA SNHG7 and SIRT3 expression. Importantly, Rg1 inhibited HG-induced HREC proliferation, migration, and angiogenesis by upregulating the lncRNA SNHG7, and miR-2116-5p had a target regulatory relationship with both lncRNA SNHG7 and SIRT3. Rg1 inhibits HG-induced proliferation, migration, angiogenesis, and VEGF expression in retinal endothelial cells through the lncRNA SNG7/miR-2116-5p/SIRT3 axis. This finding provides theoretical evidence for the clinical application of Rg1 in DR.

LncNALT knockdown ameliorates hypertensive retinopathy via PTEN/PI3K/AKT pathway

ABSTRACT This study aimed to explore the role of the long non-coding RNA NOTCH1-associated lncRNA in T cell acute lymphoblastic leukemia (lncNALT) in the pathogenesis of hypertensive retinopathy (HR). LncNALT expression levels were determined using reverse transcription-quantitative polymerase chain reaction. The effects of lncNALT knockdown on the viability, proliferation, migration, and invasion of human retinal microvascular endothelial cells (RMECs) were determined via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, 5-ethynyl-2’-deoxyuridine staining, and Transwell assays. Protein expression levels were determined using western blotting. We found that lncNALT expression levels were increased in RMECs treated with hydrogen peroxide (H2O2), while the knockdown of lncNALT rescued the viability, proliferation, migration, and invasion of RMECs treated with H2O2. Moreover, lncNALT interacted with ELAV like RNA binding protein 1 to affect the phosphatase and tensin homolog (PTEN) expression. Knockdown of lncNALT enhanced the viability, proliferation, migration, and invasion of RMECs via the PTEN/phosphoinositide 3-kinase (PI3K)/serine-threonine kinase (AKT) pathway. Taken together, knockdown of lncNALT enhanced the viability, proliferation, migration, and invasion of RMECs via the PTEN/PI3K/AKT pathway, suggesting that lncNALT could be a potential therapeutic target for patients with HR.

Upregulation of PCED1B-AS1 in proliferative diabetic retinopathy and its involvement in retinal vascular endothelial cell proliferation

BackgroundThis study was to assess the diagnostic value of PCED1B-AS1 for proliferative diabetic retinopathy (PDR) and investigate the involvement of PCED1B-AS1 in PDR.MethodsThe vitreous and blood specimens from 37 subjects with PDR and 21 non-diabetics were examined by reverse transcription quantitative PCR to determine the PCED1B-AS1 level. The two groups were age- and gender-matched. Receiver operating characteristic (ROC) curves were plotted to visually illustrate the diagnostic ability of PCED1B-AS1. Human retinal Müller glial cells were studied by ELISA. Proliferation and migration of human retinal microvascular endothelial cells (HRMECs) were assessed in vitro.ResultsSignificant increases of PCED1B-AS1 levels were observed in the vitreous samples and CD34 + VEGFR-2 + cells from blood samples of diabetic subjects with PDR, compared with those of non-diabetics. The ROC curve based on the vitreous PCED1B-AS1 levels revealed an AUC of 0.812, while the ROC curve based on the PCED1B-AS1 levels in CD34 + VEGFR-2 + cells from blood samples revealed an AUC of 0.870. In Müller cell cultures, PCED1B-AS1 siRNA significantly attenuated VEGF and MCP-1 upregulation which were induced by CoCl2 and TNF-α. Additionally, PCED1B-AS1 siRNA attenuated VEGF-induced proliferation and migration in HRMECs.ConclusionThis study revealed the potential of PCED1B-AS1 as a diagnostic biomarker for PDR. In vitro data point to the anti-angiogenic and anti-proliferation effects of PCED1B-AS1.

Long Non-coding RNA SPAG5-AS1 Attenuates Diabetic Retinal Vascular Dysfunction by Inhibiting Human Retinal Microvascular Endothelial Cell Proliferation, Migration, and Tube Formation by Regulating the MicroRNA-1224-5p/IRS-1 Axis.

Diabetic retinopathy (DR) is causal for visual impairment and blindness. The research aimed at whether and how lncRNA SPAG5-AS1 (SPAG5-AS1) is involved in retinal vascular dysfunction under diabetic conditions. After determination of SPAG5-AS1, miR-1224-5p, and IRS-1 expression in high glucose (HG)-treated human retinal microvascular endothelial cells (hRMECs), their respective influences on retinal vascular dysfunction was explored by cell counting kit-8, Transwell, wound-healing assay, and tube formation assay. SPAG5-AS1/miR-1224-5p/IRS-1 interaction was identified through bioinformatics analysis and luciferase reporter gene assays. As tested, SPAG5-AS1 and IRS-1 levels were induced, while miR-1224-5p was enhanced in HG-treated hRMECs. Up-regulating SPAG5-AS1 or downregulating miR-1224-5p could inhibit hRMECs proliferation, migration, and tube formation, and vice versa. SPAG5-AS1 can promote IRS-1 expression by miR-1224-5p, and depletion of IRS-1 was functional for the reversal of up-regulated SPAG5-AS1-modified influences on HG-treated hRMECs. Additionally, in diabetic rats, SPAG5-AS1 can alleviate retinal vascular dysfunction. All in all, SPAG5-AS1 attenuates diabetic retinal vascular dysfunction through miR-1224-5p/IRS-1 axis, providing a potential therapeutic strategy for DR.

Research on the lncRNA MALAT1 promoting the proliferation, migration and angiogenesis of retinal vascular endothelial cells in diabetic retinopathy through the molecular axis of miR-124-3p/SOX7

Research on the lncRNA MALAT1 promoting the proliferation, migration and angiogenesis of retinal vascular endothelial cells in diabetic retinopathy through the molecular axis of miR-124-3p/SOX7

Bie-Jia-Ruan-Mai-Tang, a Chinese Medicine Formula, Inhibits Retinal Neovascularization in Diabetic Mice Through Inducing the Apoptosis of Retinal Vascular Endothelial Cells.

Proliferative diabetic retinopathy (PDR) is one of the main complications of diabetes, mainly caused by the aberrant proliferation of retinal vascular endothelial cells and the formation of new blood vessels. Traditional Chinese medicines possess great potential in the prevention and treatment of PDR. Bie-Jia-Ruan-Mai-Tang (BJ), a Chinese medicine formula, has a good therapeutic effect on PDR clinically; however, the mechanism of action involved remains unclear. Therefore, we investigated the effect of BJ on PDR through in vitro and in vivo experiments. A diabetic mouse model with PDR was established by feeding a high-fat–high-glucose diet combined with an intraperitoneal injection of streptozotocin (STZ), while high-glucose-exposed human retinal capillary endothelial cells (HRCECs) were employed to mimic PDR in vitro. The in vivo experiments indicated that BJ inhibited the formation of acellular capillaries, decreased the expression of VEGF, and increased the level of ZO-1 in diabetic mice retina. In vitro experiments showed that high glucose significantly promoted cell viability and proliferation. However, BJ inhibited cell proliferation by cycle arrest in the S phase, thus leading to apoptosis; it also increased the production of ROS, decreased the mitochondrial membrane potential, reduced the ATP production, and also reduced the expressions of p-PI3K, p-AKT, and Bcl-xL, but increased the expressions of Bax and p-NF-κB. These results suggest that BJ induces the apoptosis of HRCECs exposed to high glucose through activating the mitochondrial death pathway by decreasing the PI3K/AKT signaling and increasing the NF-κB signaling to inhibit the formation of acellular capillaries in the retina, thus impeding the development of PDR.

Procollagen C-proteinase enhancer 1 promotes physiologic retinal angiogenesis via regulating the process of collagen.

To investigate the role of procollagen C-proteinase enhancer 1 (PCPE1) in retinal angiogenesis and relevant mechanisms. The Pcolce1-knockout (KO) mice were used to explore the effect of PCPE1 on retinal angiogenesis in vivo. Pcolce1 siRNA were designed, cell count kit 8 (CCK8) assays and tube formation assays were performed to investigate the cell proliferation and tube formation abilities of retinal microvascular endothelial cells (hRMECs) in vitro. Mouse embryo fibroblasts (MEF) cells were isolated and cultured to analyze the effect of PCPE1 on enhancing procollagen cleavage. In vivo studies showed that the retinal vascular density of Pcolce1-/- mice was significantly lower than that of the control group. Furthermore, silencing of Pcolce1 inhibited cell proliferation and tube formation abilities of hRMECs in vitro. Additionally, much more pro-collagen was found in Pcolce1-/- MEF cells, compared to wild type MEF cells. PCPE1 may promote physiological retinal angiogenesis by regulating the processing of collagen, which may provide a potential therapeutic target of retinal vascular disease.

Protective effect of pentraxin 3 on pathological retinal angiogenesis in an in vitro model of diabetic retinopathy

BackgroundDiabetic retinopathy (DR) is the most common retinal microvascular disease caused by diabetes. Previous studies indicated that Pentraxin 3 (PTX3), an acute phase reactant, was closely related to the development of DR. But the exact effect of PTX3 in diabetic retinopathy needs more investigations. MethodsReal-time fluorescence quantitative polymerase chain reaction (qRT-PCR) analysis and western blot (WB) were used to detect the expression of PTX3 in vitro. The Ki67 immunofluorescent staining, scratch-wound migration assay, and tube formation experiments were performed to detect the effect of PTX3 knockdown and overexpression on the fibroblast growth factor (FGF)-induced proliferation, migration and tube-forming ability of human retinal microvascular endothelial cells (HRMECs). The phosphorylation levels of extracellular regulated protein kinases (ERK) and fibroblast growth factor receptor (FGFR) in HRMECs were detected by WB. ResultsIn vitro, the mRNA and protein expressions of PTX3 in the high-concentration glucose condition group were upregulated compared with the normal group (p < 0.05). The proliferation, migration and tube-forming abilities of HRMECs exposed to high-concentration glucose were enhanced (p < 0.01, p < 0.01, p < 0.05 respectively), and the phosphorylation of FGFR and ERK1/2 were increased (p < 0.01, p < 0.05 respectively) compared with the normal condition group. Compared with the high glucose condition group, the proliferation, migration and tube-forming abilities of HRMECs in the high glucose + PTX3 siRNA condition group were further strengthened (p < 0.001, p < 0.0001, p < 0.05 respectively), and the phosphorylation of FGFR and ERK1/2 were increased (p < 0.001, p < 0.01 respectively). Compared with the high glucose condition group, the proliferation, migration and tube-forming abilities of HRMECs in the high glucose + PTX3 overexpression condition group were compromised (p < 0.001, p < 0.05, p < 0.01 respectively), and the phosphorylation of FGFR and ERK1/2 were inhibited (p < 0.001, p < 0.0001 respectively). Neither the scramble siRNA condition group nor the blank plasmid condition group showed significant difference on the proliferation, migration and tube-forming abilities of HRMECs compared with the high glucose condition group (p > 0.05). ConclusionsThe upregulated expression of PTX3 may play a protective role on pathological angiogenesis in DR. PTX3 may serve as a new target for the treatment of DR.