miR-200c serves an important role in H5V endothelial cells in high glucose by targeting Notch1

MicroRNAs as Biomarkers for Coronary Artery Disease Related to Type 2 Diabetes Mellitus-From Pathogenesis to Potential Clinical Application

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease with still growing incidence among adults and young people worldwide. Patients with T2DM are more susceptible to developing coronary artery disease (CAD) than non-diabetic individuals. The currently used diagnostic methods do not ensure the detection of CAD at an early stage. Thus, extensive research on non-invasive, blood-based biomarkers is necessary to avoid life-threatening events. MicroRNAs (miRNAs) are small, endogenous, non-coding RNAs that are stable in human body fluids and easily detectable. A number of reports have highlighted that the aberrant expression of miRNAs may impair the diversity of signaling pathways underlying the pathophysiology of atherosclerosis, which is a key player linking T2DM with CAD. The preclinical evidence suggests the atheroprotective and atherogenic influence of miRNAs on every step of T2DM-induced atherogenesis, including endothelial dysfunction, endothelial to mesenchymal transition, macrophage activation, vascular smooth muscle cells proliferation/migration, platelet hyperactivity, and calcification. Among the 122 analyzed miRNAs, 14 top miRNAs appear to be the most consistently dysregulated in T2DM and CAD, whereas 10 miRNAs are altered in T2DM, CAD, and T2DM-CAD patients. This up-to-date overview aims to discuss the role of miRNAs in the development of diabetic CAD, emphasizing their potential clinical usefulness as novel, non-invasive biomarkers and therapeutic targets for T2DM individuals with a predisposition to undergo CAD.

Deciphering the Role of miR-200c-3p in Type 1 Diabetes (Subclinical Cardiovascular Disease) and Its Correlation with Inflammation and Vascular Health

Uncomplicated type 1 diabetes (T1DM) displays all features of subclinical cardiovascular disease (CVD) as is associated with inflammation, endothelial dysfunction and low endothelial progenitor cells. MiR-200c-3p has been shown in animal tissues to be pro-atherogenic. We aimed to explore the role of miR-200c-3p in T1DM, a model of subclinical CVD. 19 samples from T1DM patients and 20 from matched controls (HC) were analyzed. MiR-200c in plasma and peripheral blood mononuclear cells (PBMCs) was measured by real-time quantitative polymerase chain reaction. The results were compared with the following indices of vascular health: circulating endothelial progenitor cells, (CD45dimCD34+VEGFR-2+ or CD45dimCD34+CD133+) and proangiogenic cells (PACs). MiR-200c-3p was significantly downregulated in PBMCs but not in plasma in T1DM. There was a significant negative correlation between the expression of miR-200c-3p and HbA1c, interleukin-7 (IL-7), vascular endothelial growth factor-C (VEGF-C), and soluble vascular cell adhesion molecule-1, and a positive correlation with CD45dimCD34+VEGFR-2+, CD45dimCD34+CD133+ and PACs. Receiver operating curve analyses showed miR-200c-3p as a biomarker for T1DM with significant downregulation of miR-200c-3p, possibly defining subclinical CVD at HbA1c > 44.8 mmol/mol (6.2%). In conclusion, downregulated miR-200c-3p in T1DM correlated with diabetic control, VEGF signaling, inflammation, vascular health and targeting VEGF signaling, and may define subclinical CVD. Further prospective studies are necessary to validate our findings in a larger group of patients.

Circ_0001897 regulates high glucose-induced angiogenesis and inflammation in retinal microvascular endothelial cells through miR-29c-3p/transforming growth factor beta 2 axis

Diabetic retinopathy (DR) has become the leading cause of blindness among adults at working age. Previous studies have implicated circ_0001897 in the development of DR. In this study, we investigated the functional roles and mechanisms of circ_0001897 in high glucose-induced angiogenesis and inflammation. Peripheral blood samples from DR patients and healthy controls were collected to examine circ_0001897 expression, which demonstrated a significant upregulation of circ_0001897 in DR patients. To investigate the functional role and mechanisms of circ_0001897, human retinal microvascular endothelial cells (HRECs) were treated with high glucose (HG) to establish an in vitro DR model of endothelial cells. HG treatment induced the upregulation of circ_0001897 in HRECs, and enhanced cell proliferation, inflammatory responses, as well as in vitro angiogenesis. Circ_0001897 knockdown significantly attenuated the cell proliferation, inflammatory responses, and angiogenesis induced by HG treatment. Mechanistically, circ_0001897 sponged and inhibited the activity of mir-29c-3p, which in turn regulates the downstream target transforming growth factor beta 2 (TGFB2). The effects of circ_0001897 knockdown could be rescued by mir-29c-3p inhibitor or TGFB2 overexpression. Collectively, our data demonstrated the novel role of circ_0001897/mir-29c-3p/TGFB2 axis in regulating HG-induced inflammation and angiogenesis of HRECs. These findings suggest that targeting circ_0001897 could serve as an intervention strategy to ameliorate DR.

Circle RNA circCSPP1 promotes human osteosarcoma cell proliferation and increases glucose metabolism by suppressing miR-200c maturation

INTRODUCTION

MiR-200c plays a central role in glucose metabolism in cancer cells. However, its upstream regulators in this process are unknown. CircRNA CSPP1 (circCSPP1) was predicted to bind to premature miR-200c, an oncogenic miRNA. Therefore, we explored their interaction in osteosarcoma (OS).

METHODS

Differential circCSPP1 and miR-200c expression in OS was analyzed using RT-qPCR. Glucose metabolism was analyzed by glucose uptake assay. Subcellular circCSPP1 location in OS cells was detected using cellular fractionation assay. The direct interaction between circCSPP1 and miR-200c was explored using RNA-RNA pull-down assay. The role of circCSPP1 in miR-200c maturation was investigated by analyzing both mature and premature miR-200c levels in OS cells with circCSPP1 overexpression.

RESULTS

CircCSPP1 and premature miR-200c levels were increased while mature miR-200c level was decreased in OS. CircCSPP1 was detected in both the nuclear and cytoplasm fractions of OS cells. CircCSPP1 directly interacted with premature miR-200c. CircCSPP1 overexpression increased premature miR-200c level, glucose uptake, and cell proliferation, but decreased mature miR-200c level. MiR-200c overexpression suppressed the role of circCSPP1 in OS cells.

CONCLUSIONS

CircCSPP1 promotes OS cell proliferation and increases glucose metabolism by suppressing miR-200c maturation.

miRNA-200c-3p targets talin-1 to regulate integrin-mediated cell adhesion

The ability of integrins on the cell surface to mediate cell adhesion to the extracellular matrix ligands is regulated by intracellular signaling cascades. During this signaling process, the talin (TLN) recruited to integrin cytoplasmic tails plays the critical role of the major adaptor protein to trigger integrin activation. Thus, intracellular levels of TLN are thought to determine integrin-mediated cellular functions. However, the epigenetic regulation of TLN expression and consequent modulation of integrin activation remain to be elucidated. Bioinformatics analysis led us to consider miR-200c-3p as a TLN1-targeting miRNA. To test this, we have generated miR-200c-3p-overexpressing and miR-200c-3p-underexpressing  cell lines, including HEK293T, HCT116, and LNCaP cells. Overexpression of miR-200c-3p resulted in a remarkable decrease in the expression of TLN1, which was associated with the suppression of integrin-mediated cell adhesion to fibronectin. In contrast, the reduction in endogenous miR-200c-3p levels led to increased expression of TLN1 and enhanced cell adhesion to fibronectin and focal adhesion plaques formation. Moreover, miR-200c-3p was found to target TLN1 by binding to its 3′-untranslated region (UTR). Taken together, our data indicate that miR-200c-3p contributes to the regulation of integrin activation and cell adhesion via the targeting of TLN1.

miR-200-3p suppresses cell proliferation and reduces apoptosis in diabetic retinopathy via blocking the TGF-β2/Smad pathway

Increasing evidence has shown that microRNAs (miRNAs) play an important role in the pathogenesis of diabetic retinopathy (DR). However, the role and mechanism of miRNA in regulating high glucose (HG)-induced ARPE-19 cell injury are still not well understood. The present study aimed to investigate the effects of miR-200a-3p on DR progression and reveal the underlying mechanisms of their effects. In the present study, we observed that miR-200a-3p was significantly decreased, while transforming growth factor-β2 (TGF-β2) expression was up-regulated in ARPE-19 cells treated with HG and retina tissues of DR rats. Subsequently, overexpression of miR-200a-3p significantly promoted cell proliferation, reduced apoptosis, as well as inhibited the levels of inflammatory cytokines secreted, matrix metalloprotease 2/9 (MMP2/9), and vascular endothelial growth factor (VEGF) in HG-injured ARPE-19 cells. Moreover, miR-200a-3p was proved to target TGF-β2 mRNA by binding to its 3′ untranslated region (3′UTR) using a luciferase reporter assay. Mechanistically, overexpression of miR-200a-3p reduced HG-induced ARPE-19 cell injury and reduced inflammatory cytokines secreted, as well as down-regulated the expression of VEGF via inactivation of the TGF-β2/Smad pathway in vitro. In vivo experiments, up-regulation of miR-200a-3p ameliorated retinal neovascularization and inflammation of DR rats. In conclusion, our findings demonstrated that miR-200a-3p-elevated prevented DR progression by blocking the TGF-β2/Smad pathway, providing a new therapeutic biomarker for DR treatment in the clinic.

Notch1 in Tumor Microvascular Endothelial Cells and Tumoral miR-34a as Prognostic Markers in Locally Advanced Triple-Negative Breast Cancer

Purpose

Triple-negative breast cancer (TNBC) is associated with poor prognosis with limited treatment options. Angiogenesis is known to be involved in the progression of TNBC, and targeting this pathway results in modest clinical benefits. In this study, we analyzed the role of tumor microvascular endothelial Notch1 (EC Notch1) and tumoral miR-34a as prognostic markers in patients with TNBC.

Methods

The expression of miR-34a was analyzed using archival tumor tissues from 114 patients with TNBC. Simultaneously, archival tumor tissues were also checked for the expression of CD34 and Notch1 by immunostaining. The ratio of Notch1-microvascular density (MVD) to CD34-MVD was defined as EC Notch1. The association between the expression of miR-34a or EC Notch1 and clinicopathological characteristics was analyzed.

Results

In the overall patient population, patients with low expression of EC Notch1 was associated with better overall survival (OS, p = 0.041) than those with high expression of EC Notch1. In lymph node-positive TNBC patients, high levels of miR-34a and low levels of EC Notch1 correlated significantly with higher survival benefits in terms of OS (p = 0.026), disease-free survival (p = 0.009), and metastasis-free survival (p = 0.038) relative to that in other patients. Decreased expression of EC Notch1 and increased expression of miR-34a also showed a survival benefit in locally advanced TNBC.

Conclusion

The fact that miR-34a and EC Notch1 are associated with the angiogenesis suggests that angiogenesis may play a role in the development and progression of TNBC.

miR-200c Prevents TGF-β1-Induced Epithelial-to-Mesenchymal Transition and Fibrogenesis in Mesothelial Cells by Targeting ZEB2 and Notch1

Peritoneal fibrosis and loss of transport function is a common complication contributing to adverse outcomes in patients on long-term peritoneal dialysis (PD). Epithelial-to-mesenchymal transition (EMT) in mesothelial cells is a salient feature, but its triggering mechanisms remain obscure. Dysregulation of microRNA (miR) expression is implicated in EMT and tissue fibrosis. We investigated the role of miR-200c in EMT and fibrogenesis in a murine PD model and in cultured peritoneal mesothelial cells. PD-fluid-treated mice showed peritoneal miR-200c expression reduced by 76.2% compared with PBS-treated mice, and this was accompanied by increased peritoneal α-smooth muscle actin, fibronectin, and collagen expression. PD fluid and TGF-β1 both reduced miR-200c expression in cultured mesothelial cells, accompanied by downregulation of E-cadherin and decorin, and induction of fibronectin, collagen I and III, and transcription factors related to EMT. Decorin prevented the suppression of miR-200c by TGF-β1. Lentivirus-mediated miR-200c overexpression prevented the induction of fibronectin, collagen I, and collagen III by TGF-β1, independent of decorin, and partially prevented E-cadherin suppression by TGF-β1. Target genes of miR-200c were identified as ZEB2 and Notch1. Our data demonstrate that miR-200c regulates EMT and fibrogenesis in mesothelial cells, and loss of peritoneal miR-200c contributes to PD-associated peritoneal fibrosis.

Suppression of microRNA-495 alleviates high-glucose-induced retinal ganglion cell apoptosis by regulating Notch/PTEN/Akt signaling

High glucose (HG)-induced apoptosis of retinal ganglion cells (RGCs) contributes to the pathogenesis of diabetic retinopathy, which is one of the most common and severe complications of diabetes mellitus. Accumulating evidence has documented that microRNAs (miRNAs) play an important role in the pathogenesis of diabetic retinopathy. However, the role of miRNAs in regulating HG-induced apoptosis of RGCs remains largely unknown. Various studies have suggested that miR-495 is an important regulator of cell apoptosis and survival. In this study, we aimed to investigate whether miR-495 is involved in regulating HG-induced apoptosis of RGCs and reveal its possible relevance in diabetic retinopathy. We found that miR-495 was significantly upregulated in HG-treated RGCs. Downregulation of miR-495 protected RGCs against HG-induced apoptosis, whereas overexpression of miR-495 had the opposite effect. Notably, Notch1 was identified as a target gene of miR-495, as miR-495 negatively regulated Notch1 expression and the Notch signaling pathway. Moreover, downregulation of miR-495 inhibited PTEN expression while promoting Akt activation. However, knockdown of Notch1 significantly abolished the protective effect of miR-495 inhibition against HG-induced apoptosis. Overall, our study suggests that downregulation of miR-495 alleviates HG-induced apoptosis of RGCs by targeting Notch1 to regulate PTEN/Akt signaling, which provides novel insights into understanding the pathogenesis of HG-induced apoptosis of RGCs.