Dysregulation of microRNA‐181b and TIMP3 is functionally involved in the pathogenesis of diabetic nephropathy

miR-181b regulates vascular endothelial aging by modulating an MAP3K3 signaling pathway

Endothelial cell (EC) aging plays a vital role in the pathogenesis of cardiovascular disease (CVD). MicroRNAs have emerged as crucial regulators of target gene expression by inhibiting mRNA translation and/or promoting mRNA degradation. We identify an aging-related and oxidative stress-responsive microRNA, miR-181b, that inhibits endothelial cell apoptosis and senescence. In gain- or loss-of-function studies, miR-181b regulated the expression of key apoptosis markers (Bcl2, Bax, cleaved-Caspase3) and senescence markers (p16, p21, γH2AX) and the ratio of apoptotic cells (TUNEL-positive) and senescent cells (SA-βgal-positive) in H₂ O₂ -induced ECs. Mechanistically, miR-181b targets MAP3K3 and modulates a MAP3K3/MKK/MAPK signaling pathway. MAP3K3 knockdown recapitulated the phenotype of miR-181b overexpression and miR-181b was dependent on MAP3K3 for regulating EC apoptosis and senescence. In vivo, miR-181b expression showed a negative correlation with increasing age in the mouse aorta. Endothelial-specific deficiency of miR-181a2b2 increased the target MAP3K3, markers of vascular senescence (p16, p21), and DNA double-strand breaks (γH2AX) in the aorta of aged mice. Collectively, this study unveils an important role of miR-181b in regulating vascular endothelial aging via an MAP3K3-MAPK signaling pathway, providing new potential therapeutic targets for antiaging therapy in CVD.

MicroRNA-494-3p Exacerbates Renal Epithelial Cell Dysfunction by Targeting SOCS6 under High Glucose Treatment

BACKGROUND

Diabetic nephropathy is a common complication of the kidneys induced by diabetes and is the main cause of end-stage renal disease. MicroRNA-494-3p was reported to be upregulated in renal tissues collected from db/db mice, but its specific role in diabetic nephropathy was still unclear. This study aimed to explore the effect of miR-494-3p on renal fibrosis using an in vitro cell model of diabetic nephropathy.

METHODS

After human renal tubular epithelial cells (HK-2) were treated with high glucose (HG), the viability and apoptosis of cells were examined by CCK-8 assays and flow cytometry analyses. Additionally, protein levels of fibronectin, collagen I, collagen III, collagen IV, and epithelial-mesenchymal transition (EMT) markers in HG-induced HK-2 cells were quantified by Western blotting. miR-494-3p expression in HK-2 cells was detected by reverse-transcription quantitative polymerase chain reaction. The binding relation between miR-494-3p and the messenger RNA suppressor of cytokine signaling 6 (SOCS6) was detected by luciferase reporter assays.

RESULTS

HG reduced cell viability and enhanced cell apoptosis in a time- or concentration-dependent manner. Additionally, HG induced collagen accumulation and triggered the EMT process. miR-494-3p was upregulated in HG-treated HK-2 cells. miR-494-3p inhibition alleviated HG-induced cell dysfunction. Mechanistically, miR-494-3p bound with SOCS6 and negatively regulated SOCS6 expression. Moreover, silencing SOCS6 rescued the suppressive effect of miR-499-5p inhibition on HG-induced cell dysfunction.

CONCLUSION

miR-494-3p aggravates renal fibrosis, EMT process, and cell apoptosis by targeting SOCS6, suggesting that the miR-494-3p/SOCS6 axis may become a potential strategy for the treatment of diabetic nephropathy.

Effect of microRNA-181b on the biological characteristics and clinical drug resistance of small-cell lung cancer by targeting angiotensin converting enzyme 2

Objective

To clarify the effect of miR‐181b on the biological function of small‐cell lung cancer (SCLC) and explore the effect of clinical resistance on SCLC.

Methods

Blood samples were collected from 30 SCLC patients and 30 non‐SCLC patients in our department from 2017 to 2019 to detect the expression level of miR‐181b.The expression level of miR‐181b was detected in SCLC cells by RT‐PCR, and screening of downstream target genes by gene chip, verification with luciferase, and Western blotting. In addition, collect the general data of 30 SCLC patients and 30 non‐SCLC patients (control group), the patients were diagnosed by pathology and undergoing EC protocol in the Department of Thoracic Surgery and Oncology of our hospital to detect the expression level of mir‐181b in different periods. Furthermore, in the SCLC cell line, EC chemotherapy was administered to detect the sensitivity of drug resistance and nondrug resistance.

Results

miR‐181b in SCLC patients was lower than in normal people as well as the drug‐sensitive cell line. ACE2 was verified as a downstream target of miR‐181b by gene chip screening. First‐line chemotherapy can promote the recovery of miR‐181b, but cannot repair to normal levels. miR‐181b can enhance the drug sensitivity of SCLC drug‐resistant cells.

Conclusion

miR‐181b directly targets ACE2 to affect the biological characteristics of SCLC. The expression level of miR‐181b is highly related to the drug resistance of SCLC, which suggests that miR‐181b could be a potential biomarker candidate for treatment efficacy of SCLC.

Lower growth arrest-specific 5 level in endometrium is related to endometriosis via promoting cell proliferation and angiogenesis

Long noncoding RNAs are a group of more than 200 nt, nonprotein coding RNAs, some of which are dysregulated in many pathophysiological processes including endometriosis. This study aims to clarify the roles of dysregulated growth arrest-specific 5 (GAS5) in patients with endometriosis, and unveil the underlying mechanisms. We obtained endometrium samples from 37 patients with endometriosis and 23 controls without endometriosis. Primary endometrial stromal cells (ESCs) and endothelial cells were separated from the endometrium. Levels of GAS5 were quantified using quantitative real-time polymerase chain reaction, and levels of p27, cleaved caspase-3, cleaved poly (ADP-Ribose) polymerase 1, vascular endothelial growth factor A, tissue inhibitor of metalloproteinases 3 (TIMP3), and trypsin-modified soy protein 10 were assessed by immunoblotting. Cell viability was examined using MTT assays, and the cell cycle and apoptosis were analyzed by flow cytometry. Endothelial cell tube formation capacity was assayed in vitro. GAS5 and p27 levels were found lower in the endometrium samples from patients with endometriosis. Primary ESCs from patients with endometriosis had increased viability, reduced apoptosis, and a relatively uncontrolled cell cycle. Gain- and loss-of-function studies confirmed that GAS5 regulated p27 expression in ESCs. Furthermore, GAS5 level was relatively low in primary endothelial cells from patients with endometriosis and GAS5 acted as an angiogenesis inhibitor by regulating the miR-181c-TIMP3 axis. Thus, lower GAS5 level in endometrium might be related to endometriosis by regulating cell proliferation, apoptosis, cell cycle, and angiogenesis.

Liraglutide Regulates the Kidney and Liver in Diabetic Nephropathy Rats through the miR-34a/SIRT1 Pathway

PURPOSE

To explore the regulatory effects of liraglutide on the kidney and liver through the miR-34a/SIRT1 pathway with related factors in diabetic nephropathy (DN) rats.

METHODS

DN rats were randomly divided into two groups (n = 10) and were injected with liraglutide or normal saline twice a day. The 24-hour urine microalbumin content and biochemical index levels were measured. qRT-PCR was performed to detect the expression of miR-34a in the kidney and liver tissues. The levels of SIRT1, HIF-1a, Egr-1, and TGF-β1 in kidney and liver tissues were determined using qRT-PCR, western blot, and immunohistochemistry. Electron microscopy and HE staining were used to observe the ultrastructure and pathological changes.

RESULTS

Liraglutide treatment in DN rats decreased blood glucose, 24-hour urine microalbumin, TC, TG, LDL-C, UA, Cr, UREA, ALT, and AST levels and increased the level of HDL-C (P < 0.05). Compared with the control group, the miR-34a levels were significantly decreased in kidney and liver tissues followed by liraglutide treatment (P < 0.05). The levels of SIRT1 in the liraglutide group are significantly higher than those in the control group with the kidney and liver tissues (P < 0.05). Conversely, the contents of HIF-1a, Egr-1, and TGF-β1 were significantly lower in the liraglutide group than in the control group (P < 0.05). Electron microscopy showed that the kidney of the liraglutide-treated group exhibited minor broadening of the mesangial areas, fewer deposits, and a well-organized foot process. HE staining revealed that the kidney of the liraglutide-treated rats had a more regular morphology of the glomerulus and Bowman sac cavity and lighter tubular edema. Additionally, the liraglutide-treated DN rats had a clear hepatic structure, a lower degree of steatosis, and mild inflammatory cell infiltration.

CONCLUSION

Liraglutide, through its effect on the miR-34a/SIRT1 pathway, may have a protective role in the kidney and liver of DN rats.

MicroRNA‑199a‑3p suppresses high glucose‑induced apoptosis and inflammation by regulating the IKKβ/NF‑κB signaling pathway in renal tubular epithelial cells

Renal tubular epithelial cells (RTEC) injury induced by hyperglycemia is considered a major contributor to the pathogenesis of diabetic nephropathy (DN). However, few studies have focused on the role of microRNAs (miRNAs/miRs) in RTEC injury. Therefore, the present study aimed to investigate the role and mechanisms of miRNAs in RTEC injury. In the study, miRNAs expression profiles were determined via microarray assay in the peripheral blood samples of patients with DN. High glucose (HG)-induced injury in HK-2 cells was used as a cell model to examine the potential role of miR-199a-3p in DN. The expression of miR-199a-3p was validated using reverse transcription-quantitative PCR. The expressions of TNF-α, IL-1β and IL-6, were detected via ELISA. The protein levels of apoptosis-related proteins were determined using western blotting. Cell apoptosis and caspase 3 activity were evaluated via flow cytometry analysis and caspase 3 activity assay, respectively. Luciferase reporter assay was used to confirm the interaction between miR-199a-3p and IKKβ. miR-199a-3p was found to be significantly downregulated in the peripheral blood samples, and there was a negative correlation between miR-199a-3p expression and proteinuria in patients with DN. It was identified that miR-199a-3p expression was time-dependently decreased in the HG-induced cell damage model. Moreover, miR-199a-3p overexpression significantly improved HG-induced cell injury, as evidenced by the decrease in cell apoptosis and inflammation. Subsequent analyses demonstrated that miR-199a-3p directly targeted IKKβ, whose expression was increased, and negatively correlated with miR-199a-3p expression in patients with DN. The protective effects of miR-199a-3p overexpression on HG-treated HK-2 cells were partially reversed by IKKβ overexpression. In addition, activation of the NF-κB pathway by HG was blocked by miR-199a-3p mimics transfection in HK-2 cells. Collectively, the present findings indicated that miR-199a-3p protected HK-2 cells against HG-induced injury via inactivation of the IKKβ/NF-κB pathway, suggesting enhanced expression of miR-199a-3p as a potential therapeutic strategy for patients with DN.

Overexpression of Linc 4930556M19Rik Suppresses High Glucose-Triggered Podocyte Apoptosis, Fibrosis and Inflammation via the miR-27a-3p/Metalloproteinase 3 (TIMP3) Axis in Diabetic Nephropathy

Background

Long non-coding RNAs (lncRNAs) play vital roles in development of diabetic nephropathy (DN). The goal of our study was to investigate the functional roles of long intergenic noncoding RNA (lincRNA) 4930556M19Rik in DN.

Material/Methods

A DN cell model was constructed by exposing podocytes to high glucose (HG). A subcellular fraction assay was used to determine the level of 4930556M19Rik in the nucleus and cytoplasm of podocytes. Quantitative real-time polymerase chain reaction was used to evaluate expression of 4930556M19Rik and miR-27a-3p. Western blot assay was used to assessed levels of fibrosis-related proteins, podocin, and tissue inhibitor of metalloproteinase 3 (TIMP3). Flow cytometry analysis was performed to analyze cell apoptosis. Enzyme linked immunosorbent assay was used to examine secretion of inflammatory cytokines. Dual-luciferase reporter, RIP, and RNA pull-down assays were used to verify the relationship between miR-27a-3p and 4930556M19Rik or TIMP3.

Results

4930556M19Rik was significantly decreased in HG-stimulated podocytes and mainly enriched in the cytoplasm of podocytes. Elevation of 4930556M19Rik hampered HG-induced cell apoptosis, fibrosis, and inflammatory in podocytes. 4930556M19Rik sponged miR-27a-3p to negatively modulate miR-27a-3p expression. MiR-27a-3p overexpression reversed the impact of 4930556M19Rik mediated cell progression in HG-induced podocytes. Moreover, TIMP3 was the target for miR-27a-3p and miR-27a-3p inhibition slowed podocyte injury by targeting TIMP3.

Conclusions

4930556M19Rik overexpression slowed HG-induced podocyte injury by downregulating miR-27a-3p and upregulating TIMP3.

MicroRNA-770-5p contributes to podocyte injury via targeting E2F3 in diabetic nephropathy

Diabetic nephropathy (DN) has been identified as the major cause of end-stage renal disease (ESRD) in most developed countries. MicroRNA-770-5p depletion could repress high glucose (HG)-triggered apoptosis in podocytes, and downregulation of E2F transcription factor 3 (E2F3) could facilitate podocyte injury. Nevertheless, whether E2F3 is involved in miR-770-5p knockdown-mediated improvement of DN is still unclear. The expression levels of miR-770-5p and E2F3 were detected in HG-treated podocytes by RT-qPCR. The expression levels of E2F3, apoptosis-related proteins Bcl-2 related X protein (Bax), B-cell lymphoma-2 (Bcl-2), Bad, apoptotic peptidase activating factor 1 (APAF1), C-caspase3, C-caspase7, and C-caspase9 were detected by western blot assay. The effects of miR-770-5p and E2F3 on HG-treated podocytes proliferation and apoptosis were detected by CCK-8 and flow cytometry assays. The interaction between miR-770-5p and E2F3 was predicted by Targetscan, and then verified by the dual-luciferase reporter assay. MiR-770-5p was upregulated and E2F3 was downregulated in HG-treated podocytes. MiR-770-5p inhibited proliferation and promoted apoptosis and E2F3 promoted proliferation and suppressed apoptosis in HG-treated podocytes. E2F3 is a target gene of miR-770-5p and it partially abolished the effect of miR-770-5p in HG-triggered proliferation and apoptosis of podocytes. MiR-770-5p deficiency blocked HG-induced APAF1/caspase9 pathway via targeting E2F3 in podocytes. We firstly confirmed that E2F3 was a target of miR-770-5p in podocytes. These findings suggested that miR-770-5p expedited podocyte injury by targeting E2F3, and the miR-770-5p/E2F3 axis might represent a pathological mechanism of DN progression.

Interactions Among Non-Coding RNAs in Diabetic Nephropathy

Diabetic Nephropathy (DN) is the most common cause of End-stage renal disease (ESRD). Although various treatments and diagnosis applications are available, DN remains a clinical and economic burden. Recent findings showed that noncoding RNAs (ncRNAs) play an important role in DN progression, potentially can be used as biomarkers and therapeutic targets. NcRNAs refers to the RNA species that do not encode for any protein, and the most known ncRNAs are the microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs). Dysregulation of these ncRNAs was reported before in DN patients and animal models of DN. Importantly, there are some interactions between these ncRNAs to regulate the crucial steps in DN progression. Here, we aimed to discuss the reported ncRNAs in DN and their interactions with critical genes in DN progression. Elucidating these ncRNAs regulatory network will allow for a better understanding of the molecular mechanisms in DN and how they can act as new biomarkers for DN and also as the potential targets for treatment.