VEGF-A inhibition ameliorates podocyte apoptosis via repression of activating protein 1 in diabetes

Stem cell-derived exosomal MicroRNAs: Potential therapies in diabetic kidney disease

The diabetic kidney disease (DKD) is chronic kidney disease caused by diabetes and one of the most common comorbidities. It is often more difficult to treat end-stage renal disease once it develops because of its complex metabolic disorders, so early prevention and treatment are important. However, currently available DKD therapies are not ideal, and novel therapeutic strategies are urgently needed. The potential of stem cell therapies partly depends on their ability to secrete exosomes. More and more studies have shown that stem cell-derived exosomes take part in the DKD pathophysiological process, which may offer an effective therapy for DKD treatment. Herein, we mainly review potential therapies of stem cell-derived exosomes mainly stem cell-derived exosomal microRNAs in DKD, including their protective effects on mesangial cells, podocytes and renal tubular epithelial cells. Using this secretome as possible therapeutic drugs without potential carcinogenicity should be the focus of further research.

Paeoniflorin binds to VEGFR2 to restore autophagy and inhibit apoptosis for podocyte protection in diabetic kidney disease through PI3K-AKT signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Paeoniflorin (PF) was found to exhibit renal protection from diabetic kidney disease (DKD) in previous trials, but its specific mechanism remains to be elucidated.

AIM OF THE STUDY

This study furtherly explored the specific mechanism of PF in protect podocyte injury in DKD.

MATERIALS AND METHODS

We observed the effects of PF on renal tissue and podocytes in DKD by constructing the vitro and vivo models after measuring the pharmacokinetic characteristics of PF. Target proteins of PF were found through target prediction, and verified by molecular docking, CESTA, and SPR, and then furtherly explored the downstream regulation mechanism related to podocyte autophagy and apoptosis by network prediction and co-immunoprecipitation. Finally, by using the target protein inhibitor in vivo and knocking down the target protein gene in vitro, it was verified that PF played a role in regulating autophagy and apoptosis through the target protein in diabetic nephropathy.

RESULTS

This study found that in STZ-induced mice model, PF could improve the renal biochemical and pathological damage and podocyte injure (p < 0.05), upregulate autophagy activity (p < 0.05), but inhibit apoptosis (p < 0.01). Vascular endothelial growth factor receptor 2 (VEGFR2), predicted as the target of PF, directly bind with PF reflected by molecular docking and surface plasmon resonance detection. Animal studies demonstrated that VEGFR2 inhibitors have a protective effect similar to that of PF on DKD. Network prediction and co-immunoprecipitation further confirmed that VEGFR2 was able to bind PIK3CA to regulate PI3K-AKT signaling pathway. Furthermore, PF downregulated the phosphorylation of PI3K and AKT (p < 0.05). In vitro, similarly to autophagy inhibitors, PF was also found to improve podocyte markers (p < 0.05) and autophagy activity (p < 0.05), decrease caspase 3 protein (p < 0.05) and further inhibited VEGFR2-PI3K-AKT activity (p < 0.05). Finally, the results of VEGFR2 knockdown were similar to the effect of PF in HG-stimulated podocytes.

CONCLUSION

In conclusion, PF restores autophagy and inhibits apoptosis by targeting the VEGFR2-mediated PI3K-AKT pathway to improve renal injury in DKD, that provided a theoretical basis for PF treatment in DKD.

miR-222 regulates cell growth, apoptosis, and autophagy of interstitial cells of Cajal isolated from slow transit constipation rats by targeting c-kit

BACKGROUND

Excessive autophagy and apoptosis of the interstitial cells of Cajal (ICC) have been identified in gastrointestinal (GI) motility disorders including slow transit constipation (STC). MicroRNA 222 (miR-222) has been shown to affect GI motility. This study aimed to explore whether miR-222 influences apoptosis and excessive autophagy of isolated ICC.

METHODS

miR-222, c-kit, and stem cell factor (SCF) were evaluated in colon tissues in STC rats compared with normal control by qRT-PCR and western blot analysis. The condition of autophagy of colon tissue was observed by transmission electron microscope. ICC were isolated from the colon of STC rats. Cell Counting Kit-8 (CCK-8) assay and wound healing assay were carried out to examine the cell viability and migration rate. Cell apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) and Annexin V-Flourescein Isothiocyanate/Propidine Iodide (FITC/PI) apoptosis detection kit. Western blot analysis was performed to detect the c-kit and SCF expression; apoptosis-related proteins Bcl-2, Bax, caspase-3, and pro-caspase-3; and autophagy-related proteins LC3B and Beclin-1. The connection between miR-222 and c-kit was detected by bioinformatics and luciferase activity analysis.

RESULTS

miR-222 expression was significantly higher, whereas c-kit and SCF expressions were markedly lower in STC rats' colon tissue compared with normal control. Meanwhile, STC rats exhibited excessive autophagy in colon tissue than normal control. Inhibition of miR-222 expression promoted cell proliferation as well as migration and inhibited autophagy, whereas upregulation of miR-222 had the opposite effect. In addition, miR-222 upregulation induced apoptosis and excessive autophagy compared with normal controls (NC). Western blot analysis showed that miR-222 overexpression caused decreased c-kit and SCF protein levels compared with NC. Bioinformatics and luciferase activity analysis revealed that miR-222 could be a predictive regulator of c-kit.

CONCLUSION

miR-222 induces apoptosis and excessive autophagy of ICC and may serve as potential biomarker for ICC loss in STC.

Glomerular Endothelial Cell Crosstalk With Podocytes in Diabetic Kidney Disease

Diabetes is the main cause of renal failure worldwide. Complications of the kidney micro-and macro-circulation are common in diabetic patients, leading to proteinuria and can progress to end-stage renal disease. Across the complex interplays aggravating diabetes kidney disease progression, lesions of the glomerular filtration barrier appear crucial. Among its components, glomerular endothelial cells are known to be central safeguards of plasma filtration. An array of evidence has recently pinpointed its intricate relations with podocytes, highly specialized pericytes surrounding glomerular capillaries. During diabetic nephropathy, endothelial cells and podocytes are stressed and damaged. Besides, each can communicate with the other, directly affecting the progression of glomerular injury. Here, we review recent studies showing how in vitro and in vivo studies help to understand pathological endothelial cells-podocytes crosstalk in diabetic kidney disease.

Pathogenesis of Fabry nephropathy: The pathways leading to fibrosis

BACKGROUND

Kidney is one of the main target organs in Fabry disease, a lysosomal X-linked genetic disorder. Renal involvement is characterized by proteinuria and progressive chronic kidney disease leading to end-stage renal disease. Pathogenic mechanisms in the progression of renal damage in Fabry disease are not thoroughly known yet. The lysosomal Gb3 deposition is the first step of complex pathological pathways resulting in renal sclerosis/fibrosis. Our hypothesis is that Fabry disease associated cellular alterations in tubular cells induce the production of TGF-β1, which mediate transdifferentiation of renal cells into myofibroblasts resulting in fibrosis of renal tissue.

OBJECTIVES

The aim of this work is to study the mechanisms leading to fibrosis in kidney from human Fabry patients.

METHODS

Fifteen renal biopsies from naïve Fabry patients were included. Histological and immunohistochemical analysis was carried out.

RESULTS

Positive staining for TGF-β1 was found in tubular epithelial cells in biopsies from Fabry patients. Apoptosis was determined by active caspase 3 staining in tubular and mesangial glomerular cells. Due to TGF-β1 is the main profibrotic cytokine and induces accumulation of myofibroblasts, we performed a study for its marker α-smooth muscle actin (α-SMA). This study revealed expression of α-SMA on pericytes surrounding peritubular capillaries, smooth muscle cells of blood vessels, mesangial cells and periglomerular zone. TGF-β1 is produced mainly by tubular cells in Fabry kidney biopsies probably inducing cellular trans-differentiation of renal cells into myofibroblasts. A positive staining for a marker of myofibroblasts was present, affirming the presence of those profibrotic cells.

CONCLUSIONS

These results show for the first time that TGF-β1 is expressed in human renal tissue from Fabry patients, and that this profibrotic cytokine is mainly produced by proximal tubular cells. In addition both, peritubular interstitium and glomeruli, presented cells positive for myofibroblasts markers.

Research Progress on the Pathological Mechanisms of Podocytes in Diabetic Nephropathy

Diabetic nephropathy (DN) is not only an important microvascular complication of diabetes but also the main cause of end-stage renal disease. Studies have shown that the occurrence and development of DN are closely related to morphological and functional changes in podocytes. A series of morphological changes after podocyte injury in DN mainly include podocyte hypertrophy, podocyte epithelial-mesenchymal transdifferentiation, podocyte detachment, and podocyte apoptosis; functional changes mainly involve podocyte autophagy. More and more studies have shown that multiple signaling pathways play important roles in the progression of podocyte injury in DN. Here, we review research progress on the pathological mechanism of morphological and functional changes in podocytes associated with DN, to provide a new target for delaying the occurrence and development of this disorder.

Advanced Oxidation Protein Products Aggravate Tubulointerstitial Fibrosis Through Protein Kinase C-Dependent Mitochondrial Injury in Early Diabetic Nephropathy

AIMS

Diabetic nephropathy (DN) is the most common microvascular complications and the principal cause of mortality and morbidity rates in patients with diabetes. The expression of advanced oxidation protein products (AOPPs) has been found in vacuolated renal tubules in DN and correlated with patients' decreased renal function. The accumulation of AOPPs is regarded as an initiating factor in podocyte injuries via the protein kinase C (PKC) signaling, which plays a critical role in triggering oxidative stress and mitochondrial injuries in diseases including DN. Whether AOPPs could induce mitochondrial injuries and fibrosis in renal tubules remains largely unknown. Herein, we tested the hypothesis that the accumulation of AOPPs in diabetes incurs mitochondrial dysfunction and oxidative stress, causing renal tubulointerstitial fibrosis (TIF) via PKC signaling pathway.

RESULTS

In vivo, intrarenal AOPPs accumulation correlated with oxidative stress, renal fibrosis, proteinuria, and declined renal function in DN patients and diabetic rats. AOPPs-induced mitochondrial injuries, apoptosis, and TIF were significantly mitigated by PKCη inhibition in diabetic rats. In vitro, high glucose (HG) stimulated AOPP expression and augmented PKC-mediated oxidative stress and fibrosis in HK-2 cells. Furthermore, we provide mechanistic evidence that inhibition of PKCη isoform alleviated mitochondrial injuries and function, attenuated apoptosis, and renal fibrosis in HG-cultured AOPPs-induced HK-2 cells. Innovation and Conclusion: We propose a novel mechanism that AOPPs-induced mitochondrial dysfunction and oxidative stress cause TIF in DN via activation of the PKCη isoform.

Modulation of vascular endothelial growth factor and mitogen-activated protein kinase-related pathway involved in extracorporeal shockwave therapy accelerate diabetic wound healing

Extracorporeal shockwave therapy (ESWT) has a significant positive effect to accelerate chronic wound healing. This study investigated whether the vascular endothelial growth factor (VEGF)-related pathway has involved in ESWT enhancement of diabetic wound healing. A dorsal skin defect (area, 6 × 5 cm) in a streptozotocin-induced diabetes rodent model was used. Thirty-two male Wistar rats were divided into four groups. Group I consisted of nondiabetic control; group II, diabetic control without treatment; group III, diabetic rats received ESWT; and group IV, rats received Avastin (a VEGF monoclonal antibody) on day 0 (post-wounding immediately) to day 7 and ESWT on day 3 and day 7. The wound healing was assessed clinically. The VEGF, endothelial nitric oxide synthase (eNOS), and Ki-67 were analyzed with immunohistochemical staining. The mRNA expression of mitogen-activated protein kinase-related genes was measured by real-time quantitative real-time polymerase chain reaction. The results revealed wound size was significantly reduced in the ESWT-treated rats as compared to the diabetic control (p < 0.01). The positive effect of ESWT-increasing wound healing was significantly suppressed in pretreatment of the Avastin group. Histological findings revealed significant increase in neo-vessels in the ESWT group as compared to the control. In immunohistochemical stain, significant increases in VEGF, eNOS, and Ki-67 expressions were noted in the ESWT group as compared to that in controls. However, Avastin suppressed the shockwave effect and down-regulation of VEGF, eNOS, and Ki-67 expressions in the Avastin-ESWT group as compared to that in the ESWT alone group. We found that highly mRNA expression of Kras, Raf1, Mek1, Jnkk, Jnk, and Jun at early stage in the ESWT group, as compared to the diabetic control. These evidences indicated treatment with multiple sessions of ESWT significantly enhanced diabetic wound healing associated with increased neovascularization and tissue regeneration. The bio-mechanism of ESWT-enhanced wound healing is correlated with VEGF and mitogen-activated protein kinase-mediated pathway.

Long Noncoding RNA LINC01619 Regulates MicroRNA-27a/Forkhead Box Protein O1 and Endoplasmic Reticulum Stress-Mediated Podocyte Injury in Diabetic Nephropathy

AIMS

Altered activities of long noncoding RNAs (lncRNAs) have been implicated in the regulation of microRNAs. microRNA-27a (miR-27a) upregulation has been shown to induce endoplasmic reticulum (ER) stress podocyte injury in diabetic nephropathy (DN). Herein, we aim to interrogate the mutually regulated network of miR-27a with long intergenic noncoding RNA 1619 (LINC01619) and the target gene.

RESULTS

LINC01619 downregulation was found in human DN renal biopsy tissues and contributed to proteinuria and diminished renal function. LINC01619 was expressed in podocyte cytoplasm and involved in ER stress signaling pathway. LINC01619 exerted biological function by serving as a "sponge" for miR-27a, which negatively targeted forkhead box protein O1 (FOXO1) and activated ER stress. In diabetic rats and high-glucose cultured podocytes, LINC01619 triggered oxidative stress and podocyte injuries as demonstrated by increased apoptosis, diffuse podocyte foot process effacement, and decreased renal function. Innovation and Conclusion: This study demonstrates that LINC01619 functions as a competing endogenous RNA and regulates miR-27a/FOXO1-mediated ER stress and podocyte injury in DN. Antioxid. Redox Signal. 29, 355-376.

Silencing of c-jun decreases cell migration, invasion, and EMT in radioresistant human nasopharyngeal carcinoma cell line CNE-2R

BACKGROUND

Previously, we found that c-jun was highly expressed in radiation-resistant human nasopharyngeal carcinoma cells (CNE-2R) compared with human nasopharyngeal carcinoma cells (CNE-2).

MATERIALS AND METHODS

In this study, we first used the scratch assays and transwell assays to detect the migration and invasion of CNE-2R and CNE-2 cells and tested the epithelial mesenchymal transformation (EMT)-related proteins E-cadherin and N-cadherin by Western blot analysis. Subsequently, c-jun was knocked down to establish the effect of c-jun on EMT, migration, and invasion of CNE-2R cells both in vitro and in vivo.

RESULTS

A high EMT level, CNE-2R cells were more capable of migration and invasion than CNE-2 cells. Moreover, silencing of c-jun has upregulated the expression of E-cadherin and downregulated N-cadherin in CNE-2R cells, and subsequently the migration and invasion capacity of the cells was decreased. Consistent with in vitro results, in vivo studies indicated that the c-jun silencing reduced pulmonary migration of CNE-2R cells. Immunohistochemistry of lung metastatic tumor tissue showed that E-cadherin was upregulated, and N-cadherin was downregulated.

CONCLUSION

These findings suggest that silencing of c-jun in CNE-2R cells reduces cells migration, invasion, and EMT both in vitro and in vivo.

MicroRNA-27a promotes renal tubulointerstitial fibrosis via suppressing PPARγ pathway in diabetic nephropathy

MicroRNA-27a (miR-27a) upregulation has been identified in diabetes, but the pathogenesis of miR-27a in renal tubulointerstitial fibrosis (TIF) in diabetic nephropathy (DN) has not been elucidated. Herein, we found that high glucose stimulated miR-27a expression, which directly inhibited PPARγ and promoted fibrosis in NRK-52E cells. The functional relevance of miR-27a-dependent PPARγ decrease was proven by inhibition or overexpression of miR-27a both in vitro and in streptozotocin-induced diabetic rats. MiR-27a, via repression of PPARγ, activates the TGF-β/Smad3 signaling and contributes to the expressional changes of connective tissue growth factor (CTGF), Fibronectin and Collagen I, key mediators of fibrosis. Furthermore, we provide evidences that plasma miR-27a upregulation contributed to unfavorable renal function and increased TIF in renal tissues of diabetic rats and DN patients. Notably, miR-27a exhibited clinical and biological relevance as it was linked to elevated serum creatinine, proteinuria, urinary N-acetyl-β-D-glucosaminidase (NAG), and reduced estimated glomerular filtration rate (eGFR). Thus, we propose a novel role of the miR-27a-PPARγ axis in fostering the progression toward more deteriorated renal TIF in DN. Monitoring plasma miR-27a level and its association with PPARγ can be used to reflect the severity of renal TIF. Targeting miR-27a could be evaluated as a potential therapeutic approach for DN.

CDK5 promotes renal tubulointerstitial fibrosis in diabetic nephropathy via ERK1/2/PPARγ pathway

Cyclin-dependent kinase 5 (CDK5) has been documented in podocyte injuries in diabetic nephropathy (DN), however its role in renal tubular epithelial cells has not been elucidated. We report here that CDK5 is detrimental and promotes tubulointerstitial fibrosis (TIF) via the extracellular signal-regulated kinase 1/2 (ERK1/2)/peroxisome proliferator-activated receptor gamma (PPRAγ) pathway in DN. In high glucose cultured NRK52E cells, blocking CDK5 activity inhibited epithelial-to-mesenchymal transition (EMT) and fibrosis via ERK1/2/PPARγ pathway. In diabetic rats, CDK5 inhibitor roscovitine decreased renal fibrosis and improved renal function as demonstrated by a decrease in levels of blood urine nitrogen (BUN), serum creatinine and β2-microglobulin. Further studies revealed that improved renal fibrosis and function in diabetic rats were associated with inactivation of ERK1/2 and PPARγ signaling pathways. In late staged DN patients, the upregulation of CDK5 and p35 activated phosphorylated ERK1/2 and PPARγ, leading to decreased levels of E-cadherin but increased Vimentin and Collagen IV. Accordingly, renal fibrosis and function were worsened as revealed by decreased estimated glomerular filtration rate (eGFR) and increased serum BUN, creatinine, β2-microglobulin, 24-hour proteinuria and urine albumin to creatinine ratio (UACR). These findings demonstrate a novel mechanism that CDK5 increases tubulointerstitial fibrosis by activating the ERK1/2/PPARγ pathway and EMT in DN. CDK5 might have therapeutic potential in diabetic nephropathy.

VEGFA Involves in the Use of Fluvastatin and Zoledronate Against Breast Cancer

Our study aimed to identify key genes involved in the use of fluvastatin and zoledronate against breast cancer, as well as to investigate the roles of vascular endothelial growth factor A (VEGFA) in the malignant behaviors of breast cancer cells. The expression data GSE33552 was downloaded from Gene Expression Omnibus database, including mocked-, fluvastatin- and zoledronate-treated MDA-MB-231 cells. Differentially expressed genes (DEGs) were identified in fluvastatin- and zoledronate-treated cells using limma package, respectively. Pathway enrichment analysis and protein-protein interaction (PPI) network analysis were then performed. Then we used shRNA specifically targeting VEGFA (shVEGFA) to knock down the expression of VEGFA in MDA-MB-231 cells. Cell viability assay, scratch wound healing assay, Transwell invasion assay and flow cytometry were performed to explore the effects of VEGFA knockdown on the malignant behaviors of breast cancer cells. VEGFA was up-regulated in both fluvastatin- and zoledronate-treated breast cancer cells. Moreover, VEGFA was a hub node in PPI network. In addition, VEGFA was successfully knocked down in MDA-MB-231 cells by shVEGFA. Suppression of VEGFA promoted the migration and invasion of breast cancer MDA-MB-231 cells. Suppression of VEGFA inhibited the apoptosis of MDA-MB-231 cells. Our results indicate that up-regulation of VEGFA may prevent the progression of breast cancer after fluvastatin and zoledronate treatment via inducing cell apoptosis and inhibiting migration and invasion. VEGFA may serve as a potential prognostic indicator for clinical outcome in the management of breast cancer.

WT1 ameliorates podocyte injury via repression of EZH2/β-catenin pathway in diabetic nephropathy

Epigenetic modulation of podocyte injury plays a pivotal role in diabetic nephropathy (DN). Wilm's tumor 1 (WT1) has been found to have opposing roles with β-catenin in podocyte biology. Herein, we asked whether the histone methyltransferase enzyme enhancer of zeste homolog 2 (EZH2) promotes WT1-induced podocyte injury via β-catenin activation and the underlying mechanisms. We found that WT1 antagonized EZH2 and ameliorated β-catenin-mediated podocyte injury as demonstrated by attenuated podocyte mesenchymal transition, maintenance of podocyte architectural integrity, decreased podocyte apoptosis and oxidative stress. Further, we provided mechanistical evidence that EZH2 was required in WT1-mediated β-catenin inactivation via repression of secreted frizzled-related protein 1 (SFRP-1), a Wnt antagonist. Moreover, EZH2-mediated silencing of SFRP-1 was due to increased histone 3 lysine 27 trimethylation (H3K27me3) on its promoter region. WT1 favored renal function and decreased podocyte injury in diabetic rats and DN patients. Notably, WT1 exhibited clinical and biological relevance as it was linked to dropped serum creatinine, decreased proteinuria and elevated estimated glomerular filtration rate (eGFR). We propose an epigenetic process via the WT1/EZH2/β-catenin axis in attenuating podocyte injury in DN. Targeting WT1 and EZH2 could be potential therapeutic approaches for DN.

MicroRNA-27a promotes podocyte injury via PPARγ-mediated β-catenin activation in diabetic nephropathy

Podocyte injury has a pivotal role in the pathogenesis of diabetic nephropathy (DN). MicroRNA-27a (miR-27a), peroxisome proliferator-activated receptor γ (PPARγ) and β-catenin pathways have been involved in the pathogenesis of DN. Herein, we asked whether miR-27a mediates podocyte injury through PPARγ/β-catenin signaling in DN. The functional relevance of miR-27a, PPARγ and β-catenin were investigated in cultured podocytes and glomeruli of diabetic rats and patients using in vitro and in vivo approaches. Podocyte injury was assessed by migration, invasion and apoptosis assay. Biological parameters were analyzed using enzyme-linked immunosorbent assay. We found that high glucose stimulated miR-27a expression, which, by negatively targeting PPARγ, activated β-catenin signaling as evidenced by upregulation of β-catenin target genes, snail1 and α-smooth muscle actin (α-SMA) and downregulation of podocyte-specific markers podocin and synaptopodin. These changes caused podocyte injury as demonstrated by increased podocyte mesenchymal transition, disrupted podocyte architectural integrity and increased podocyte apoptosis. Furthermore, we provide evidence that miR-27a contributed to unfavorable renal function and increased podocyte injury in diabetic rats. Notably, miR-27a exhibited clinical and biological relevance as it was linked to elevated serum creatinine, proteinuria and reduced creatinine clearance rate. In addition, miR-27a upregulation and activation of PPARγ/β-catenin signaling were verified in renal biopsy samples from DN patients. We propose a novel role of the miR-27a/PPARγ/β-catenin axis in fostering the progression toward more deteriorated podocyte injury in DN. Targeting miR-27a could be a potential therapeutic approach for DN.

Glomerular cell crosstalk

Purpose of review

Glomerular filtration occurs in specialized, microscopic organelles. Each glomerulus contains unique cells and these cooperate to maintain normal filtration. Phenomenal adaptation is required for the glomerulus to respond to variable mechanical loads and this adaptation requires efficient communication between the resident cells. This review will focus on the latest discoveries related to signalling events that mediate the crosstalk between glomerular cells, and detail how disease processes can influence normal regulation.

Recent findings

New data indicate that the crosstalk between glomerular cells involves an increasing number of secreted signalling ligands that act in an autocrine or paracrine fashion. Furthermore, extended roles for some of the classical signalling molecules have been described and there is emerging evidence of therapeutic strategies to manipulate cellular crosstalk. The glomerular extracellular matrix harbours many of these signalling ligands, acting as a reservoir and presenting ligands to cell surface receptors. Signals can also be transferred between cells by extracellular vesicles and this is an emerging concept in cellular crosstalk.

Summary

Recent discoveries are building our understanding about glomerular cell crosstalk, and this review focuses on growth factors and signalling peptides, methods of delivery to target cells, and the potential for developing new therapies for glomerular disease.

MicroRNA-130b promotes lung cancer progression via PPARγ/VEGF-A/BCL-2-mediated suppression of apoptosis

Background

The prognosis of non-small-cell lung cancer (NSCLC) is poor yet mechanistic understanding and therapeutic options remain limited. We investigated the biological and clinical significance of microRNA-130b and its relationship with apoptosis in NSCLC.

Methods

The level of microRNA-130b in relationship with the expression of PPARγ, VEGF-A, BCL-2 and apoptosis were analyzed in 91 lung cancer patient samples using immunohistochemistry and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay on tissue microarrays. Gain and loss-of-function studies were performed to investigate the effects of microRNA-130b, peroxisome proliferator-activated receptor γ (PPARγ) or vascular endothelial growth factor-A (VEGF-A) on biological functions of lung cancer cells using in vitro and in vivo approaches.

Results

MicroRNA-130b up-regulation conferred unfavorable prognosis of lung cancer patients. Notably, microRNA-130b targeted PPARγ and inhibiting microRNA-130b markedly repressed proliferation, invasion and metastasis of lung cancer cells, leading to increased apoptosis. MicroRNA-130b-dependent biologic effects were due to suppression of PPARγ that in turn activated BCL-2, the key mediator of anti-apoptosis. Administration of microRNA-130b mimic to mouse xenografts promoted tumor growth. In vitro and in vivo, miR-130b enrichment associated with down-regulation of PPARγ, up-regulation of VEGF-A and BCL-2, and decreased apoptosis.

Conclusions

The present study demonstrates that microRNA-130b promotes lung cancer progression via PPARγ/VEGF-A/BCL-2-mediated suppression of apoptosis. Targeting microRNA-130b might have remarkable therapeutic potential for lung cancer therapy.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-016-0382-3) contains supplementary material, which is available to authorized users.

MicroRNA-130b improves renal tubulointerstitial fibrosis via repression of Snail-induced epithelial-mesenchymal transition in diabetic nephropathy

MicroRNA-130b (miR-130b) downregulation has been identified in diabetes, but the role and mechanisms for miR-130b in mediating renal tubulointerstitial fibrosis in diabetic nephropathy (DN) remain unknown. We demonstrated that plasma miR-130b downregulation exhibited clinical and biological relevance as it was linked to increased serum creatinine, β2-microglobulin and proteinuria, increased Snail expression and tubulointerstitial fibrosis in renal biopsies of DN patients. MiR-130b inhibitor caused Snail upregulation and enhanced molecular features of epithelial-to-mesenchymal transition (EMT) in high glucose (30 mM) cultured NRK-52E cells. In contrast, miR-130b mimic downregulated Snail expression and increased epithelial hallmarks. Notably, Snail was identified as an miR-130b direct target and inversely correlated with E-CADHERIN expression. Furthermore, the miR-130b-dependent effects were due to Snail suppression that in turn deregulated E-CADHERIN, VIMENTIN, COLLAGEN IV and α-smooth muscle actin (α-SMA), key mediators of EMT. These effects were reproduced in streptozotocin-induced diabetic rats. Thus, we propose a novel role of the miR-130b-SNAIL axis in fostering EMT and progression toward increased tubulointerstitial fibrosis in DN. Detection of plasma miR-130b and its association with SNAIL can be extrapolated to quantifying the severity of renal tubulointerstitial fibrosis. Targeting miR-130b could be evaluated as a potential therapeutic approach for DN.