MicroRNA-30e targets BNIP3L to protect against aldosterone-induced podocyte apoptosis and mitochondrial dysfunction

miR-137 regulates autophagy and apoptosis in duodenal ulcer by targeting BNIP3L

BACKGROUND

Duodenal ulcer (DU) represents a clinical manifestation and disease state that occurs when the mucosal surface of the duodenum is damaged. The processes of autophagy and apoptosis have been linked to the development of DU, yet the precise roles they play remain unclear. This study aimed to investigate the expression and mechanism of action of microRNAs (miRNA)-137 (miR-137) in DU.

METHODS

Dysregulated miRNAs and targeted genes were identified from the Gene Expression Omnibus database, and the immune cell infiltration levels were analyzed using CIBERSORT. To confirm the targeting of the miRNAs, we conducted dual luciferase reporter assays in vitro. The detection of cell apoptosis was conducted using flow cytometry. Moreover, quantitative reverse transcription polymerase chain reaction, cell counting kit-8, and Western blot were employed to ascertain the levels of autophagy- and apoptosis-related proteins.

RESULTS

Bioinformatics analysis identified 5 miRNAs, with miR-137 showing the most pronounced dysregulation. Its target gene, BNIP3L, was subsequently identified. In vitro experiments confirmed that miR-137 targeted BNIP3L. The upregulation of miR-137 expression in HIEC-6 cells resulted in the inhibition of BNIP3L expression, a reduction in autophagy, and an increase in apoptosis. A reduction in the expression of miR-137 would have the opposite effect.

CONCLUSIONS

miR-137 is upregulated in DU patients and contributes to ulcer progression by inhibiting BNIP3L, reducing autophagy, and promoting apoptosis. Targeting miR-137 could provide a novel therapeutic strategy for DU management.

BNIP3 and Nix: Atypical regulators of cell fate

Since their discovery nearly 25 years ago, the BCL-2 family members BNIP3 and BNIP3L (aka Nix) have been labelled 'atypical'. Originally, this was because BNIP3 and Nix have divergent BH3 domains compared to other BCL-2 proteins. In addition, this atypical BH3 domain is dispensable for inducing cell death, which is also unusual for a 'death gene'. Instead, BNIP3 and Nix utilize a transmembrane domain, which allows for dimerization and insertion into and through organelle membranes to elicit cell death. Much has been learned regarding the biological function of these two atypical death genes, including their role in metabolic stress, where BNIP3 is responsive to hypoxia, while Nix responds variably to hypoxia and is also down-stream of PKC signaling and lipotoxic stress. Interestingly, both BNIP3 and Nix respond to signals related to cell atrophy. In addition, our current view of regulated cell death has expanded to include forms of necrosis such as necroptosis, pyroptosis, ferroptosis, and permeability transition-mediated cell death where BNIP3 and Nix have been shown to play context- and cell-type specific roles. Perhaps the most intriguing discoveries in recent years are the results demonstrating roles for BNIP3 and Nix outside of the purview of death genes, such as regulation of proliferation, differentiation/maturation, mitochondrial dynamics, macro- and selective-autophagy. We provide a historical and unbiased overview of these 'death genes', including new information related to alternative splicing and post-translational modification. In addition, we propose to redefine these two atypical members of the BCL-2 family as versatile regulators of cell fate.

MiR-30a-5p Alters Epidermal Terminal Differentiation during Aging by Regulating BNIP3L/NIX-Dependent Mitophagy

Chronological aging is characterized by an alteration in the genes' regulatory network. In human skin, epidermal keratinocytes fail to differentiate properly with aging, leading to the weakening of the epidermal function. MiR-30a is particularly overexpressed with epidermal aging, but the downstream molecular mechanisms are still uncovered. The aim of this study was to decipher the effects of miR-30a overexpression in the human epidermis, with a focus on keratinocyte differentiation. We formally identified the mitophagy receptor BNIP3L as a direct target of miR-30a. Using a 3D organotypic model of reconstructed human epidermis overexpressing miR-30a, we observed a strong reduction in BNIP3L expression in the granular layer. In human epidermal sections of skin biopsies from donors of different ages, we observed a similar pattern of BNIP3L decreasing with aging. Moreover, human primary keratinocytes undergoing differentiation in vitro also showed a decreased expression of BNIP3L with age, together with a retention of mitochondria. Moreover, aging is associated with altered mitochondrial metabolism in primary keratinocytes, including decreased ATP-linked respiration. Thus, miR-30a is a negative regulator of programmed mitophagy during keratinocytes terminal differentiation, impairing epidermal homeostasis with aging.

MicroRNA expression profiles analysis of apheresis platelets treated with vitamin B2 and ultraviolet-B during storage

Whether platelet (PLT) microRNA (miRNA) profiles are affected by pathogen reduction technology (PRT) using vitamin B₂ and ultraviolet-B (VB₂-PRT) remains unclear. Samples from VB₂-PRT-treated (experimental group, E_) and untreated (control group, C_) apheresis PLTs were taken on days 1, 3 and 5 of storage, designated as E_1, E_3, E_5, C_1, C_3 and C_5, respectively. The miRNA expression profiles were assessed by DNA Nano Ball (DNB) sequencing technology, and verified by quantitive real-time fluorescence quantitative PCR (qRT-PCR). Compared with the expression profiles of PLT miRNAs, 3895 miRNAs were identified in the E_ groups while 4106 were in the C_ groups. There were 487 significant differentially expressed miRNAs in E_1 vs C_1 group, including 220 upregulated and 287 downregulated, such as miR-146a-5p and let-7b-5p. There were 908 significant differentially expressed miRNAs in E_3 vs C_3 group, including 297 upregulated and 611 downregulated, such as miR-142-5p and miR-7-5p. There were 229 significant differentially expressed miRNAs in E_5 vs C_5 group, including 80 upregulated and 149 downregulated, such as miR-3529-3p and miR-451a. These differentially expressed miRNAs had been suggested to have functional roles in energy homeostasis, cell communication, proliferation, migration and apoptosis. GO analysis showed a significant enrichmen in relevant biological process categories as receptor activity, signal transduction, cell transport, motility and chemotaxis. The significantly enriched KEGG pathway of predicted target genes was Glycosaminoglycan biosynthesis in E_ vs C_ groups. These new observation could provide insights on the understanding of change of miRNA profiles of PLT treated with VB₂-PRT.

MicroRNAs as Biomarkers for Nephrotic Syndrome

Nephrotic syndrome represents the clinical situation characterized by presence of massive proteinuria and low serum protein caused by a variety of diseases, including minimal change nephrotic syndrome (MCNS), focal segmental glomerulosclerosis (FSGS) and membranous glomerulonephropathy. Differentiating between diagnoses requires invasive renal biopsies in general. Even with the biopsy, we encounter difficulties to differentiate MCNS and FSGS in some cases. There is no other better option currently available for the diagnosis other than renal biopsy. MicroRNAs (miRNAs) are no-coding RNAs of approximately 20 nucleotides in length, which regulate target genes in the post-transcriptional processes and have essential roles in many diseases. MiRNAs in serum and urine have been shown as non-invasive biomarkers in multiple diseases, including renal diseases. In this article, we summarize the current knowledge of miRNAs as the promising biomarkers for nephrotic syndrome.

Reduced Lon protease 1 expression in podocytes contributes to the pathogenesis of podocytopathy

Emerging evidence has shown that mitochondrial dysfunction is closely related to the pathogenesis of podocytopathy, but the molecular mechanisms mediating mitochondrial dysfunction in podocytes remain unclear. Lon protease 1 is an important soluble protease localized in the mitochondrial matrix, although its exact role in podocyte injury has yet to be determined. Here we investigated the specific role of this protease in podocyte in glomerular injury and the progression of podocytopathy using podocyte-specific Lon protease 1 knockout mice, murine podocytes in culture and kidney biopsy samples from patients with focal segmental glomerular sclerosis and minimal change disease. Downregulated expression of Lon protease 1 was observed in glomeruli of kidney biopsy samples demonstrating a negative correlation with urinary protein levels and glomerular pathology of patients with focal segmental glomerular sclerosis and minimal change disease. Podocyte-specific deletion of Lon protease 1 caused severe proteinuria, impaired kidney function, severe kidney injury and even mortality in mice. Mechanistically, we found that continuous podocyte Lon protease 1 ablation induced mitochondrial homeostasis imbalance and dysfunction, which then led to podocyte injury and glomerular sclerosis. In vitro experiments implicated the kidney protective effect of Lon protease 1, which inhibited mitochondrial dysfunction and podocyte apoptosis. Thus, our findings suggest that the regulation of Lon protease 1 in podocytes may provide a novel therapeutic approach for the podocytopathy.

Immunomodulatory and Regenerative Effects of Mesenchymal Stem Cell-Derived Extracellular Vesicles in Renal Diseases

Mesenchymal stem cells (MSCs) have immunomodulatory and regenerative effects in many organs, including the kidney. Emerging evidence has shown that the trophic effects from MSCs are mainly mediated by the paracrine mechanism rather than the direct differentiation of MSCs into injured tissues. These secretomes from MSCs include cytokines, growth factors, chemokines and extracellular vesicles (EVs) containing microRNAs, mRNAs, and proteins. Many research studies have revealed that secretomes from MSCs have potential to ameliorate renal injury in renal disease models, including acute kidney injury and chronic kidney disease through a variety of mechanisms. These trophic mechanisms include immunomodulatory and regenerative effects. In addition, accumulating evidence has uncovered the specific factors and therapeutic mechanisms in MSC-derived EVs. In this article, we summarize the recent advances of immunomodulatory and regenerative effects of EVs from MSCs, especially focusing on the microRNAs.

The microRNA in ventricular remodeling: the miR-30 family

Ventricular remodeling (VR) is a complex pathological process of cardiomyocyte apoptosis, cardiac hypertrophy, and myocardial fibrosis, which is often caused by various cardiovascular diseases (CVDs) such as hypertension, acute myocardial infarction, heart failure (HF), etc. It is also an independent risk factor for a variety of CVDs, which will eventually to damage the heart function, promote cardiovascular events, and lead to an increase in mortality. MicroRNAs (miRNAs) can participate in a variety of CVDs through post-transcriptional regulation of target gene proteins. Among them, microRNA-30 (miR-30) is one of the most abundant miRNAs in the heart. In recent years, the study found that the miR-30 family can participate in VR through a variety of mechanisms, including autophagy, apoptosis, oxidative stress, and inflammation. VR is commonly found in ischemic heart disease (IHD), hypertensive heart disease (HHD), diabetic cardiomyopathy (DCM), antineoplastic drug cardiotoxicity (CTX), and other CVDs. Therefore, we will review the relevant mechanisms of the miR-30 in VR induced by various diseases.

MiR-30e-5p and MiR-15a-5p Expressions in Plasma and Urine of Type 1 Diabetic Patients With Diabetic Kidney Disease

Introduction

Diabetic kidney disease (DKD) is a common microvascular complication that affects 40% of patients with diabetes mellitus (DM). Emerging evidence suggests a role for several microRNAs (miRNAs) in the development of DKD. In this context, miR-15a-5p and miR-30e-5p have been shown to regulate the expression of the uncoupling protein 2 (UCP2), a mitochondrial protein that decreases reactive oxygen species (ROS) formation by the mitochondria. Since ROS overproduction is a key contributor to the pathogenesis of DKD, dysregulation of these two miRNAs could be involved in DKD pathogenesis. Thus, the aim of this study was to compare the expressions of miR-15a-5p and miR-30e-5p in type 1 DM (T1DM) patients with DKD (cases) and without this complication (controls), and to perform bioinformatics analyses to investigate their putative targets and biological pathways under their regulation.

Methods

MiR-15a-5p and miR-30e-5p expressions were analyzed in plasma and urine of 17 T1DM controls and 23 DKD cases (12 with moderate DKD and 11 with severe DKD) using qPCR. Bioinformatics analyses were performed in Cytoscape software.

Results

MiR-30e-5p expression was downregulated in plasma of patients with moderate and severe DKD compared to T1DM controls. Moreover, this miRNA was also downregulated in urine of patients with severe DKD compared to the other groups. No difference was found in miR-15a-5p expression between groups. Bioinformatics analyses indicated that miR-30e-5p and miR-15a-5p regulate various genes that participate in pathways related to angiogenesis, apoptosis, cell differentiation, oxidative stress, and hypoxia.

Conclusion

MiR-30e-5p seems to be downregulated in plasma and urine of patients with DKD.

Regulation of Aldosterone Signaling by MicroRNAs

The mineralocorticoid hormone aldosterone is released by the adrenal glands in a homeostatic mechanism to regulate blood volume. Several cues elicit aldosterone release, and the long-term action of the hormone is to restore blood pressure and/or increase the retrieval of sodium from filtered plasma in the kidney. While the signaling cascade that results in aldosterone release is well studied, the impact of this hormone on tissues and cells in various organ systems is pleotropic. Emerging evidence indicates aldosterone may alter non-coding RNAs (ncRNAs) to integrate the hormonal response, and these ncRNAs may contribute to the heterogeneity of signaling outcomes in aldosterone target tissues. The best studied of the ncRNAs in aldosterone action are the small ncRNAs, microRNAs. MicroRNA expression is regulated by aldosterone stimulation, and microRNAs are able to modulate protein expression at all steps in the renin-angiotensin-aldosterone-signaling system. The discovery and synthesis of microRNAs will be briefly covered followed by a discussion of the reciprocal role of aldosterone/microRNA regulation, including misregulation of microRNA signaling in aldosterone-linked disease states.

Identification of genes and signaling pathways associated with the pathogenesis of juvenile spondyloarthritis

The aim of the present study was to identify key genes and signaling pathways associated with the pathogenesis of juvenile spondyloarthritis (JSA). The gene expression profile dataset GSE58667, including data from 15 human whole blood samples collected from 11 patients with JSA and four healthy controls, was analyzed to identify differentially expressed genes (DEGs) associated with disease characteristics. Additionally, Gene Ontology term and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of the DEGs were performed. Protein‑protein, microRNA‑transcription factor and chemical‑gene interaction networks were constructed. A total of 326 DEGs, 196 upregulated and 130 downregulated, were identified. DEGs, including C‑X‑C motif chemokine ligand 5 (CXCL5), BCL2 interacting protein 3 like (BNIP3L), dual specificity phosphatase 5 (DUSP5) and tumor protein p53 (TP53) were enriched in functions associated with apoptosis, the cell cycle and immune responses. KEGG pathway enrichment analysis revealed that pathways associated with inflammation and the mitogen‑activated protein kinase 1 (MAPK) signaling pathway were the most enriched by DEGs. The results of the present study indicated that the MAPK signaling pathway and four genes, including CXCL5, BNIP3L, DUSP5 and TP53, may be implicated in the pathogenesis of JSA.

Protective effects of microRNA-330 on amyloid β-protein production, oxidative stress, and mitochondrial dysfunction in Alzheimer's disease by targeting VAV1 via the MAPK signaling pathway

This study aims to explore the effect of miR-330 targeting VAV1 on amyloid β-protein (Aβ) production, oxidative stress (OS), and mitochondrial dysfunction in Alzheimer's disease (AD) mice through the MAPK signaling pathway. Putative targeted gene of miR-330 was performed by a miRNA target prediction website and dual-luciferase reporter gene assay. AD mouse model was successfully established. Fourteen C57 mice were randomized into AD and control groups. The positive protein expression rate of VAV1 was measured by immunohistochemistry. Neuron cells were assigned into control, blank, negative control (NC), miR-330 mimics, miR-330 inhibitors, siRNA-VAV1, and miR-330 inhibitors + siRNA-VAV1 groups. Expression of miR-330, VAV1, ERK1, JNK1, P38MAPK, Aβ, COX, and lipoprotein receptor-related protein-1 (LRP-1) were determined using RT-qPCR and Western blotting. Colorimetry was applied to measure the levels of OS parameters of superoxide dismutase (SOD) and malondialdehyde (MDA). Aβ production in brain tissue was detected using ELISA, while that in neuron cell was measured by radioimmunoassay. MiR-330 was down-regulated in neuron cells of AD mice and VAV1 was negatively regulated by miR-330. Compared with the control group, the positive protein expression rate of VAV1 was significantly elevated in the AD group. Overexpression of miR-330 decreased the expression of VAV1, ERK1, JNK1, P38MAPK, and Aβ, but increased the expression of COX and LRP-1. AD mice revealed elevated Aβ production and MDA with decreased SOD level. The result indicates that overexpressed miR-330 targeting VAV1 through the MAPK signaling pathway reduces Aβ production and alleviates OS and mitochondrial dysfunction in AD.

MicroRNA-25 inhibits high glucose-induced apoptosis in renal tubular epithelial cells via PTEN/AKT pathway

Diabetic nephropathy (DN) has become the major cause of end-stage renal disease (ESRD). It has been demonstrated that apoptosis of renal tubular epithelial cells induced by hyperglycemia contributes to the pathogenesis of DN. Recent researches have corroborated the critical roles of microRNAs (miRNAs) in the apoptosis of various types of cells including renal tubular epithelial cells. However, the eff ; ;ect of miRNAs on the hyperglycemia-induced apoptosis of renal tubular epithelial cells remains unclear. The aim of this study is to explore the eff ; ;ect of miRNAs on the hyperglycemia-induced apoptosis of renal tubular epithelial cells and its molecular mechanism. Using a miRNA microarray, miRNAs putatively associated with DN were examined in renal biopsy tissue samples from DN patients and healthy controls. Validation analysis of miR-25 level in serum samples and renal biopsy tissue samples was performed using quantitative reverse transcription PCR (qRT-PCR). Then, gain- and loss- of function experiments were performed to determine the protective roles of miR-25 in high glucose-induced damage to renal tubular epithelial cells. Furthermore, the target gene of miR-25 and the downstream signaling pathway were also investigated. Microarray analysis and qRT-PCR revealed that miR-25 was significantly downregulated in renal biopsy tissue and serum samples from DN patients. We also observed that an inverse relationship between serum miR-25 level and proteinuria in DN patients. Meanwhile, miR-25 was decreased in human kidney (HK-2) cells subjected to HG treatment in a time dependent manner. Its overexpression reduced production of reactive oxygen species (ROS), suppressed cell apoptosis in HG-induced cell damage model, which was coupled with the decreased expression of cleaved caspase-3 and activity of caspase-3. Subsequent analyses demonstrated that phosphatase and tensin homolog deleted on chromosome ten (PTEN) was a direct and functional target of miR-25, which was validated by the dual luciferase reporter assay. Most importantly, the overexpression of PTEN effectively reversed the protective effects of miR-25 mimics on renal tubular epithelial cell injury. We also found that the anti-apoptotic effects of miR-25 are dependent on the activation of PTEN/Akt pathway. In addition, we observed that PTEN was upregulated in renal biopsy tissue samples from patients with DN, and an inverse relationship was found between PTEN and miR-25 expression, suggesting that miR-25 may exert its function through regulation of PTEN in DN. Taken together, our study proved that overexpression of miR-25 could ameliorate HG-induced oxidative stress and apoptosis in renal tubular epithelial cells through activation of PTEN/AKT pathway, suggesting that overexpression of miR-25 might provide a potential therapeutic approach for DN.

MicroRNA-30c-5p ameliorates hypoxia-reoxygenation-induced tubular epithelial cell injury via HIF1α stabilization by targeting SOCS3

The cellular hypoxia-reoxygenation (H/R) model is an ideal method to study ischemia-reperfusion injury, which is associated with high mortality. The role of microRNA-30c-5p (miR-30c-5p) in the H/R epithelial cell model remains unknown. In the current study, we observed a significant reduction in apoptosis when miR-30c-5p was up-regulated. We also found decreased levels of C-caspase-3 (C-CASP3) and Bcl-2-associated X (BAX) proteins and increased levels of B-cell lymphoma-2 (BCL2). Epidermal growth factor receptor (EGFR) showed similar results. Down-regulating miR-30c-5p increased the levels of apoptosis and C-CASP3 and BAX expression; additionally, cell proliferation was inhibited. Hypoxia-inducible factor 1α (HIF1α) protein expression levels were up-regulated in response to up-regulation of miR-30c-5p expression. The anti-apoptotic and proliferative effects of miR-30c-5p decreased significantly after the HIF1α protein levels were knocked down. Using a luciferase reporter assay, we confirmed that miR-30c-5p targets suppressor of cytokine signaling-3 (SOCS3). HIF1α levels increased when SOCS3 was blocked. Our data show that SOCS3 expression enhances apoptosis in the H/R model. In conclusion, up-regulating miR-30c-5p protects cells from H/R -induced apoptosis and induces cell proliferation; furthermore, HIF1α markedly contributes to this protective effect. MiR-30c-5p stabilizes HIF1α expression by targeting SOCS3 to achieve anti-apoptotic and proliferative effects.

MiR-30c regulates cisplatin-induced apoptosis of renal tubular epithelial cells by targeting Bnip3L and Hspa5

As a common anticancer drug, cisplatin has been widely used for treating tumors in the clinic. However, its side effects, especially its nephrotoxicity, noticeably restrict the application of cisplatin. Therefore, it is imperative to investigate the mechanism of renal injury and explore the corresponding remedies. In this study, we showed the phenotypes of the renal tubules and epithelial cell death as well as elevated cleaved-caspase3- and TUNEL-positive cells in rats intraperitoneally injected with cisplatin. Similar cisplatin-induced cell apoptosis was found in HK-2 and NRK-52E cells exposed to cisplatin as well. In both models of cisplatin-induced apoptosis in vivo and in vitro, quantitative PCR data displayed reductions in miR-30a-e expression levels, indicating that miR-30 might be involved in regulating cisplatin-induced cell apoptosis. This was further confirmed when the effects of cisplatin-induced cell apoptosis were found to be closely correlated with alterations in miR-30c expression, which were manipulated by transfection of either the miR-30c mimic or miR-30c inhibitor in HK-2 and NRK-52E cells. Using bioinformatics tools, including TargetScan and a gene expression database (Gene Expression Omnibus), Adrb1, Bnip3L, Hspa5 and MAP3K12 were predicted to be putative target genes of miR-30c in cisplatin-induced apoptosis. Subsequently, Bnip3L and Hspa5 were confirmed to be the target genes after determining the expression of these putative genes following manipulation of miR-30c expression levels in HK-2 cells. Taken together, our current experiments reveal that miR-30c is certainly involved in regulating the renal tubular cell apoptosis induced by cisplatin, which might supply a new strategy to minimize cisplatin-induced nephrotoxicity.