lncRNA MALAT1 mediated high glucose-induced HK-2 cell epithelial-to-mesenchymal transition and injury

Constructing the biomolecular networks associated with diabetic nephropathy and dissecting the effects of biomolecule variation underlying pathogenesis

Diabetic nephropathy (DN) is a common and serious complication of diabetes, contributing significantly to patient mortality. Complication of DN (CDN) ranks as the second leading cause of end-stage renal disease globally. To address this, understanding the genetic regulation underlying DN is crucial for personalized treatment strategies. In this study, we identified genes and lncRNAs associated with diabetes and diabetic nephropathy constructing a DN-related lncRNA-mRNA network (DNLMN). This network, characterized by scale-free biomolecular properties, generated through the study of topological properties, elucidates key regulatory interactions. Enrichment analysis of important network modules revealed critical biological processes and pathways involved in DN pathogenesis. In the second step, we investigated the differential expression and co-expression of hub nodes in diseased and normal individuals, identifying lncRNA-mRNA relationships implicated in disease regulation. Finally, we gathered DN-related single nucleotide polymorphisms (SNPs) and lncRNAs from the LincSNP 3.0 database. The DNLMN encompasses SNP-associated lncRNAs, and transcription factors (TFs) linked to differentially expressed lncRNAs between diseased and normal samples. These results underscore the significance of biomolecular networks in disease progression and highlighting the role of biomolecular variability contributes to personalized disease phenotyping and treatment.

Targeting lncRNA MALAT1: A Promising Approach to Overcome Metabolic Syndrome

Metabolic syndrome (MetS) is a collection of metabolic abnormalities including insulin resistance, atherogenic dyslipidemia, central obesity, and hypertension. Recently, long noncoding RNAs (lncRNAs) have emerged as pivotal regulators of metabolic balance, influencing the genes associated with MetS. Although the prevalence of insulin resistance is rising, leading to an increased risk of type 2 diabetes mellitus (T2DM) and its vascular complications, there is still a notable gap in understanding the role of lncRNAs in the context of clinical diabetes. Among lncRNAs, lung adenocarcinoma metastasis-associated transcript 1 (MALAT1) has been identified as a significant regulator of metabolism-related disorders, including T2DM and cardiovascular disease (CVD). This review explores the mechanism of lncRNA MALAT1 and suggests that targeting it could offer a promising strategy to combat MetS, thereby enhancing the prognosis of MetS.

Potential inhibitory effect of Auricularia auricula polysaccharide on advanced glycation end-products (AGEs)

In this study, a novel polysaccharide, AAP-2S, was extracted from Auricularia auricula, and the anti-glycosylation effect of AAP-2S and its underlying mechanisms were investigated using an in vitro BSA-fructose model and a cellular model. The results demonstrated the inhibiting formation of advanced glycation end products (AGEs) in vitro by AAP-2S. Concurrently, it attenuated oxidative damage to proteins in the model, preserved protein sulfhydryl groups from oxidation, reduced protein carbonylation, prevented structural alterations in proteins, and decreased the formation of β-crosslinked structures. Furthermore, AAP-2S demonstrated metal-chelating capabilities. GC-MS/MS-based metabolomics were employed to analyze changes in metabolic profiles induced by AAP-2S in a CML-induced HK-2 cell model. Mechanistic investigations revealed that AAP-2S could mitigate glycosylation and ameliorate cell fibrosis by modulating the RAGE/TGF-β/NOX4 pathway. This study provides a foundational framework for further exploration of Auricularia auricular polysaccharide as a natural anti-AGEs agent, paving the way for its potential development and application as a food additive.

Molybdenum exposure induces inflammatory response via the regulatory effects of lncRNA-00072124/miR-308/OSMR crosstalk on JAK/STAT axis in duck kidneys

Molybdenum (Mo) is an essential nutrient in living organisms. Although numerous researchers have noticed the health damage caused by excessive Mo, the underlying mechanism of excessive Mo-induced nephrotoxicity remains poorly understood. A gene crosstalk called competitive endogenous RNAs (ceRNAs) can interpret many regulatory mechanisms molecularly. But there are few researches have tried to explain the damage mechanism of excess Mo to organisms through ceRNAs network. To clarify this, the study explored the changes in lncRNAs and miRNAs expression profiles in the kidney of ducks exposed to excess Mo for 16 weeks. The sequencing results showed that Mo exposure caused differential expression of 144 lncRNAs and 14 miRNAs. The occurrence of inflammation through the JAK/STAT axis was observed and the lncRNA-00072124/miR-308/OSMR axis was verified by a double luciferase reporter assay. Overexpression of miR-308 and RNA interference of OSMR reduced Mo-induced inflammatory factors, while miR-308 knockdown showed the opposite effect. Simultaneously, lncRNA-00072124 affected OSMR function as a ceRNA. Taken together, these results concluded that Mo exposure activated the JAK/STAT axis and induced inflammation mediated by the lncRNA-00072124/miR-308/OSMR crosstalk. The results might provide new views for revealing the toxic effects of excess Mo in duck kidneys.

LncRNA as a regulator in the development of diabetic complications

Diabetes is a metabolic disease characterized by hyperglycemia, which induces the production of AGEs, ROS, inflammatory cytokines, and growth factors, leading to the formation of vascular dysfunction and target organ damage, promoting the development of diabetic complications. Diabetic nephropathy, retinopathy, and cardiomyopathy are common complications of diabetes, which are major contributors to disability and death in people with diabetes. Long non-coding RNAs affect gene transcription, mRNA stability, and translation efficiency to influence gene expression for a variety of biological functions. Over the past decade, it has been demonstrated that dysregulated long non-coding RNAs are extensively engaged in the pathogenesis of many diseases, including diabetic complications. Thus, this review discusses the regulations of long non-coding RNAs on the primary pathogenesis of diabetic complications (oxidative stress, inflammation, fibrosis, and microvascular dysfunction), and some of these long non-coding RNAs may function as potential biomarkers or therapeutic targets for diabetic complications.

From LncRNA to metastasis: The MALAT1-EMT axis in cancer progression

Cancer is a complex disease that causes abnormal genetic changes and unchecked cellular growth. It also causes a disruption in the normal regulatory processes that leads to the creation of malignant tissue. The complex interplay of genetic, environmental, and epigenetic variables influences its etiology. Long non-coding RNAs (LncRNAs) have emerged as pivotal contributors within the intricate landscape of cancer biology, orchestrating an array of multifaceted cellular processes that substantiate the processes of carcinogenesis and metastasis. Metastasis is a crucial driver of cancer mortality. Among these, MALAT1 (Metastasis-Associated Lung Adenocarcinoma Transcript 1) has drawn a lot of interest for its function in encouraging metastasis via controlling the Epithelial-Mesenchymal Transition (EMT) procedure. MALAT1 exerts a pivotal influence on the process of EMT, thereby promoting metastasis to distant organs. The mechanistic underpinning of this phenomenon involves the orchestration of an intricate regulatory network encompassing transcription factors, signalling cascades, and genes intricately associated with the EMT process by MALAT1. Its crucial function in transforming tumor cells into an aggressive phenotype is highlighted by its capacity to influence the expression of essential EMT effectors such as N-cadherin, E-cadherin, and Snail. An understanding of the MALAT1-EMT axis provides potential therapeutic approaches for cancer intervention. Targeting MALAT1 or its downstream EMT effectors may reduce the spread of metastatic disease and improve the effectiveness of already available therapies. Understanding the MALAT1-EMT axis holds significant clinical implications. Therefore, directing attention towards MALAT1 or its downstream mediators could present innovative therapeutic strategies for mitigating metastasis and improving patient prognosis. This study highlights the importance of MALAT1 in cancer biology and its potential for cutting back on metastatic disease with novel treatment strategies.

Astragalus polysaccharide promotes autophagy and alleviates diabetic nephropathy by targeting the lncRNA Gm41268/PRLR pathway

BACKGROUND

Astragalus polysaccharide (APS) is a major bioactive component of the Chinese herb astragalus, with well-established protective effects on the kidney. However, the effect of APS on diabetic nephropathy (DN) is unclear.

METHODS

Long non-coding RNA (lncRNA) expression profiles in kidney samples from control, db/db, and APS-treated db/db mice were evaluated using RNA high-throughput sequencing techniques. Additionally, rat renal tubular epithelial (NRK-52E) cells were cultured in high glucose (HG) media. We inhibited the expression of Gm41268 and prolactin receptor (PRLR) by transfecting NRK-52E cells with Gm41268-targeting antisense oligonucleotides and PRLR siRNA.

RESULTS

We found that APS treatment reduced 24-h urinary protein levels and fasting blood glucose and improved glucose intolerance and pathological renal damage in db/db mice. Furthermore, APS treatment enhanced autophagy and alleviated fibrosis in the db/db mice. We identified a novel lncRNA, Gm41268, which was differentially expressed in the three groups, and the cis-regulatory target gene PRLR. APS treatment induced autophagy by reducing p62 and p-mammalian target of rapamycin (mTOR) protein levels and increasing the LC3 II/I ratio. Furthermore, APS alleviated fibrosis by downregulating fibronectin (FN), transforming growth factor-β (TGF-β), and collagen IV levels. In addition, APS reversed the HG-induced overexpression of Gm41268 and PRLR. Reduction of Gm41268 decreased PRLR expression, restored autophagy, and ameliorated renal fibrosis in vitro. Inhibition of PRLR could enhance the protective effect of APS.

CONCLUSIONS

In summary, we demonstrated that the therapeutic effect of APS on DN is mediated via the Gm41268/PRLR pathway. This information contributes to the exploration of bioactive constituents in Chinese herbs as potential treatments for DN.

METTL14 promotes the development of diabetic kidney disease by regulating m6A modification of TUG1

BACKGROUND

Diabetic kidney disease (DKD) is one of the most common diabetic complications. Endoplasmic reticulum stress (ERS) is an important step for renal tubular epithelial cell apoptosis during DKD progression. Herein, the role and regulatory mechanism of METTL14 in ERS during DKD progression were investigated.

METHODS

DKD animal and cell models were established by streptozotocin (STZ) and high glucose (HG), respectively. HE and Masson staining were performed to analyze renal lesions in DKD mouse. Cell viability and proliferation were determined by MTT and EdU staining, respectively. HK2 cell apoptosis was analyzed by flow cytometry. TUG1 m6A level was determined by Me-RIP. The interaction between TUG1, LIN28B and MAPK1 was analyzed by RIP and RNA pull-down assays.

RESULTS

HG stimulation promoted apoptosis and increased ERS marker proteins (GRP78, CHOP and caspase12) expression in HK2 cells, while these changes were reversed by METTL14 knockdown. METTL14 inhibited TUG1 stability and expression level in an m6A-dependent manner. As expected, TUG1 knockdown abrogated METTL14 knockdown's inhibition on HG-induced HK2 cell apoptosis and ERS. In addition, TUG1 inactivated MAPK1/ERK signaling by binding with LIN28B. And TUG1 overexpression's repression on HG-induced HK2 cell apoptosis and ERS was abrogated by MAPK1 signaling activation. Meanwhile, METTL14 knockdown or TUG1 overexpression protected against STZ-induced renal lesions and renal fibrosis in DKD mouse.

CONCLUSION

METTL14 promoted renal tubular epithelial cell apoptosis and ERS by activating MAPK/ERK pathway through m6A modification of TUG1, thereby accelerating DKD progression.

Loganin reduces diabetic kidney injury by inhibiting the activation of NLRP3 inflammasome-mediated pyroptosis

Diabetic kidney disease (DKD) is an essential cause of end-stage renal disease. The ongoing inflammatory response in the proximal tubule promotes the progression of DKD. Timely and effective blockade of the inflammatory process to protect the kidney during DKD progression is a proven strategy. The purpose of this study was to investigate the protective effect of loganin on diabetic nephropathy in vivo and in vitro and whether this effect was related to the inhibition of pyroptosis. The results indicated that loganin reduced fasting blood glucose, blood urea nitrogen and serum creatinine concentrations, and alleviated renal pathological changes in DKD mice. In parallel, loganin downregulated the expression of pyroptosis related proteins in the renal tubules of DKD mice and decreased serum levels of interleukin-1beta (IL-1β) and interleukin-18 (IL-18). Furthermore, in vitro experiments showed that loganin attenuated high glucose-induced HK-2 cell injury by reducing the expression of pyroptosis-related proteins, and cytokine levels were also decreased. These fundings were also confirmed in the polyphyllin VI (PPVI) -induced HK-2 cell pyroptosis model. Loganin reduces high glucose induced HK-2 cells pyroptosis by inhibiting reactive oxygen species (ROS) production and NOD-like receptor protein 3 (NLRP3) inflammasome activation. In conclusion, the inhibition of pyroptosis via inhibition of the NLRP3/Caspase-1/Gasdermin D (GSDMD) pathway might be an essential mechanism for loganin treatment of DKD.

MALAT1 binds to miR-188-3p to regulate ALOX5 activity in the lung inflammatory response of neonatal bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) causes high morbidity and mortality in infants, but no effective preventive or therapeutic agents have been developed to combat BPD. In this study, we assessed the expression of MALAT1 and ALOX5 in peripheral blood mononuclear cells from BPD neonates, hyperoxia-induced rat models and lung epithelial cell lines. Interestingly, we found upregulated expression of MALAT1 and ALOX5 in the experimental groups, along with upregulated expression of proinflammatory cytokines. According to bioinformatics prediction, MALAT1 and ALOX5 simultaneously bind to miR-188-3p, which was downregulated in the experimental groups above. Silencing MALAT1 or ALOX5 and overexpressing miR-188-3p inhibited apoptosis and promoted the proliferation of hyperoxia-treated A549 cells. Suppressing MALAT1 or overexpressing miR-188-3p increased the expression levels of miR-188-3p but decreased the expression levels of ALOX5. Moreover, RNA immunoprecipitation (RIP) and luciferase assays showed that MALAT1 directly targeted miR-188-3p to regulate ALOX5 expression in BPD neonates. Collectively, our study demonstrates that MALAT1 regulates ALOX5 expression by binding to miR-188-3p, providing novel insights into potential therapeutics for BPD treatment.

The role of chromatin-modifying enzymes and histone modifications in the modulation of p16 gene in fumonisin B1-induced toxicity in human kidney cells

Fumonisin B₁ (FB₁) poses a risk to animal and human health. Although the effects of FB₁ on sphingolipid metabolism are well documented, there are limited studies covering the epigenetic modifications and early molecular alterations associated with carcinogenesis pathways caused by FB₁ nephrotoxicity. The present study investigates the effects of FB₁ on global DNA methylation, chromatin-modifying enzymes, and histone modification levels of the p16 gene in human kidney cells (HK-2) after 24 h exposure. An increase (2.23-fold) in the levels of 5-methylcytosine (5-mC) at 100 µmol/L was observed, a change independent from the decrease in gene expression levels of DNA methyltransferase 1 (DNMT1) at 50 and 100 µmol/L; however, DNMT3a and DNMT3b were significantly upregulated at 100 µmol/L of FB₁. Dose-dependent downregulation of chromatin-modifying genes was observed after FB₁ exposure. In addition, chromatin immunoprecipitation results showed that 10 µmol/L of FB₁ induced a significant decrease in H3K9ac, H3K9me3 and H3K27me3 modifications of p16, while 100 µmol/L of FB₁ caused a significant increase in H3K27me3 levels of p16. Taken together, the results suggest that epigenetic mechanisms might play a role in FB₁ carcinogenesis through DNA methylation, and histone and chromatin modifications.

Matrine-induced nephrotoxicity via GSK-3β/nrf2-mediated mitochondria-dependent apoptosis

INTRODUCTION

Matrine (MT), an ingredient extracted from the Chinese herb Sophora flavescens, can result in nephrotoxicity because of long-term exposure. However, the underlying mechanism by which MT leads to kidney injury remains unclear. This study aimed to investigate the roles of oxidative stress and mitochondria in MT-induced kidney toxicity both in vitro and in vivo.

METHODS

Mice were exposed to MT for 20 days, and NRK-52E cells were exposed to MT with or without LiCl (a GSK-3β inhibitor), tert-Butylhydroquinone (t-BHQ, an Nrf2 activator), or small interfering RNA.

RESULTS

The results showed that MT caused nephrotoxicity accompanied by an increase in reactive oxygen species (ROS) accumulation and mitochondrial dysfunction. Meanwhile, MT significantly upregulated glycogen synthase kinase-3β (GSK-3β) activity, released cytochrome c (Cyt C) and cleaved caspase-3, decreased the activity of nuclear factor-erythroid 2-related Factor 2 (Nrf2), and reduced the expression of heme oxygenase-1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO-1), which led to the inactivation of antioxidant enzymes and the activation of apoptosis. In addition, GSK-3β inhibition by LiCl or small interfering RNA pretreatment or Nrf2 activation by t-BHQ pretreatment attenuated the toxic effects of MT in NRK-52E cells.

CONCLUSIONS

Taken together, these results revealed that MT-induced apoptosis triggered kidney toxicity and that GSK-3β or Nrf2 might serve as a promising nephroprotective target for MT-induced kidney injury.

High glucose induces an activated state of partial epithelial-mesenchymal transition in human primary tubular cell cultures

Tubulointerstitial fibrosis is observed in diabetic nephropathy. It is still debated whether tubular cells, undergoing epithelial-mesenchymal transition (EMT) in high glucose (HG) conditions, may contribute to interstitial fibrosis development. In this study, we investigated the phenotypic and molecular EMT-like changes and the alteration of inflammatory and fibrogenic secretome induced by HG in human primary tubular cell cultures. Taking advantage of this in vitro cell model composed of proximal and distal tubular cells, we showed that HG-treated tubular cells acquired a fibroblast-like morphology with increased cytoplasmic stress fibers, maintaining the expression of the epithelial markers specific of proximal and distal tubular cells. HG increased Snail1, miRNA210 and Vimentin mesenchymal markers, decreased N-cadherin expression and migration ability of primary tubular cells, while E-cadherin expression and focal adhesion distribution were not affected. Furthermore, HG treatment of tubular cells altered the inflammatory cytokine secretion creating a secretome able to enhance the proliferation and migration of fibroblasts. Our findings show that HG promotes an activated state of partial EMT in human tubular primary cells and induces a pro-inflammatory and pro-fibrogenic microenvironment, supporting the active role of tubular cells in diabetic nephropathy onset.

XIST silencing alleviated inflammation and mesangial cells proliferation in diabetic nephropathy by sponging miR-485

In this study, we investigated the role of XIST in the development of diabetic nephropathy (DN) and further explored its underlying mechanism. qRT-PCR was used to examine the level of XIST in serum of DN patients. ELISA, MTT, and flow cytometry were used to investigate the effect of XIST on biological functions of human mesangial cells (HMCs) treated with high glucose. The recovery experiments were used to explore the potential mechanism. The result showed XIST expression was elevated significantly in serums of DN patients. XIST silencing alleviated the induction of high glucose in biological behaviour of HMCs. Besides, miR-485 inhibitor revised the suppression by si-XIST in biological behaviour of high glucose induced HMCs. Furthermore, PSMB8 mimic relieved the inhibition of si-XIST in biological behaviour of high glucose induced HMCs. In short, XIST silencing could alleviate biological process and inflammation of HMCs treated with high glucose by sponging miR-485.

The role of lncRNAs in regulation of DKD and diabetes-related cancer

Diabetes mellitus often results in several complications, such as diabetic kidney disease (DKD) and end-stage renal diseases (ESRDs). Cancer patients often have the dysregulated glucose metabolism. Abnormal glucose metabolism can enhance the tumor malignant progression. Recently, lncRNAs have been reported to regulate the key proteins and signaling pathways in DKD development and progression and in cancer patients with diabetes. In this review article, we elaborate the evidence to support the function of lncRNAs in development of DKD and diabetes-associated cancer. Moreover, we envisage that lncRNAs could be diagnosis and prognosis biomarkers for DKD and cancer patients with diabetes. Furthermore, we delineated that targeting lncRNAs might be an alternative approach for treating DKD and cancer with dysregulated glucose metabolism.

LncRNAs regulate ferroptosis to affect diabetes and its complications

Worldwide, the rapid increase in the incidence of diabetes and its complications poses a serious threat to human health. Ferroptosis, which is a new nonapoptotic form of cell death, has been proven to be closely related to the occurrence and development of diabetes and its complications. In recent years, lncRNAs have been confirmed to be involved in the occurrence and development of diabetes and play an important role in regulating ferroptosis. An increasing number of studies have shown that lncRNAs can affect the occurrence and development of diabetes and its complications by regulating ferroptosis. Therefore, lncRNAs have great potential as therapeutic targets for regulating ferroptosis-mediated diabetes and its complications. This paper reviewed the potential impact and regulatory mechanism of ferroptosis on diabetes and its complications, focusing on the effects of lncRNAs on the occurrence and development of ferroptosis-mediated diabetes and its complications and the regulation of ferroptosis-inducing reactive oxygen species, the key ferroptosis regulator Nrf2 and the NF-κB signaling pathway to provide new therapeutic strategies for the development of lncRNA-regulated ferroptosis-targeted drugs to treat diabetes.

lncRNA MALAT1 Promotes Diabetic Nephropathy Progression via miR-15b-5p/TLR4 Signaling Axis

Objective

The long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) are closely associated with the pathogenesis of diabetic nephropathy (DN). But a complete mechanism for MALAT1 in DN has yet to be identified. This study investigated the effect of MALAT1 on DN through the regulation of miR-15b-5p/TLR4 signaling.

Method

Renal tissues were collected from DN patients. Human renal tubular epithelial cells (HK-2) were used as a model of DN induced by high glucose (HG). We then measured the viability, apoptosis, and inflammatory cytokine levels of HK-2 cells using the corresponding assays. Following transfections of si-MALAT1, si-MALAT1+miR-15b-5p inhibitor, or si-MALAT1+vector TLR4 into HG-stimulated HK-2 cells, cell viability, apoptosis, and inflammatory cytokines were again measured. Furthermore, dual-luciferase reporter assay validated the interactions of MALAT1/miR-15b-5p and miR-15b-5p/TLR4. In addition, the interaction between MALAT1 and miR-15b-5p was investigated by RNA immunoprecipitation (RIP).

Results

A significant upregulation of MALAT1 was observed in DN kidney tissues, as well as in HG-stimulated HK-2 cells. MALAT1 knockdown attenuates the inhibition of cell viability, apoptosis, and inflammatory response induced by HG in HK-2 cells. Moreover, a miR-15b-5p inhibitor or TLR4 overexpression reversed the above effects induced by MALAT1 knockdown.

Conclusion

These results indicate that reduced MALAT1 ameliorates HG-stimulated HK-2 cell damage through an inhibition of the miR-15b-5p/TLR4 axis. MALAT1 may serve as a biomarker and potential therapeutic target for DN.

Long Non-Coding RNAs in the Pathogenesis of Diabetic Kidney Disease

Diabetic kidney disease (DKD) is one of the major microvascular complications of diabetes mellitus, with relatively high morbidity and mortality globally but still in short therapeutic options. Over the decades, a large body of data has demonstrated that oxidative stress, inflammatory responses, and hemodynamic disorders might exert critical influence in the initiation and development of DKD, whereas the delicate pathogenesis of DKD remains profoundly elusive. Recently, long non-coding RNAs (lncRNAs), extensively studied in the field of cancer, are attracting increasing attentions on the development of diabetes mellitus and its complications including DKD, diabetic retinopathy, and diabetic cardiomyopathy. In this review, we chiefly focused on abnormal expression and function of lncRNAs in major resident cells (mesangial cell, endothelial cell, podocyte, and tubular epithelial cell) in the kidney, summarized the critical roles of lncRNAs in the pathogenesis of DKD, and elaborated their potential therapeutic significance, in order to advance our knowledge in this field, which might help in future research and clinical treatment for the disease.

Icariin inhibits epithelial mesenchymal transition of renal tubular epithelial cells via regulating the miR-122-5p/FOXP2 axis in diabetic nephropathy rats

Epithelial mesenchymal transition (EMT) of renal tubular epithelial cells (RTECs) dominates the pathology of diabetic nephropathy (DN). microRNAs (miRNAs) can influence the fate of DN via regulation of EMT. This study aimed to analyze the role of Icariin (ICA) in EMT of RTECs, hoping to provide theoretical basis for DN management. The DN rat model was established using streptozocin, followed by ICA treatment, histopathological observation, and detection of creatinine and blood urea nitrogen. In vitro cell models were established using high glucose (HG), followed by assessment of cell proliferation, apoptosis, and migration, and E-cadherin, α-SMA, miR-122-5p, and FOXP2 expressions. Cells were transfected with miR-122-5p mimics or si-FOXP2 for joint experiments with ICA. The targeting relationship between miR-122-5p and FOXP2 was verified. ICA repaired renal dysfunctions and glomerular structure abnormities of DN rats in a dose-dependent manner. In vitro, ICA improved proliferation while suppressed migration, apoptosis, and EMT of RTECs. miR-122-5p was up-regulated in DN rats and suppressed by ICA, and miR-122-5p targeted FOXP2. miR-122-5p up-regulation or FOXP2 down-regulation reversed the protective effects of ICA on HG-induced RTECs. Overall, our finding ascertained that ICA inhibited miR-122-5p to promote FOXP2 transcription, thereby attenuating EMT of RTECs and renal injury in DN rats.

LncRNA NEAT2 Modulates Pyroptosis of Renal Tubular Cells Induced by High Glucose in Diabetic Nephropathy (DN) by via miR-206 Regulation

Patients suffering from terminal-stage diabetic nephropathy (DN) are commonly diagnosed with kidney failure. The condition of DN patients gets generally improved by long-chain noncoding RNA (LncRNA) since it regulates microRNA (miR). The current study analyzes the role played by NEAT2/miR-206 upon cell death of renal tubular epithelial cells (RTECs), high glucose (HG)-induced inflammation and oxidative stress in diabetic nephropathy (DN). The researcher used high glucose (HG) to treat HK-2 cells in in vitro conditions to establish the DN cell model. qRT-PCR was used to confirm the transfection effect whereas the researcher also tested NEAT2, nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain containing (NLRP3), caspase-1, interleukin IL-1β, gasdermin D (GSMDD)-N, and miR-206. To analyze the proteins in caspase-1, IL-1β, GSMDD-N, and NLRP3, Western blot technique was performed. The technique is also used to observe the pyroptosis. To identify TNF-α, IL-6, MCP-9, NEAT2, miR-206, and NLRP3, dual-luciferase reporter assay was conducted through ELISA kit to emphasize the correlation that exists among the above-mentioned factors. NEAT2 has been confirmed to have bound with miR-206 through double luciferase report experiments as well as RNA immunoprecipitation (RIP). NEAT2, present in HK-2 cells, was induced by HG. So, if NEAT2 is knocked down, it would mitigate TNF-α, IL-6, and MCP-9 as well. Among the HK-2 cells intervened with HG, the overexpressed miR-206 that was transfected into cells was in alignment with the modifications introduced in inflammatory factors and cytokines after NEAT2 is knocked down. The current study concludes that if NEAT2 is upregulated, it has the potential to retreat the inhibition of miR-206 on inflammatory response as well pyroptosis. Further, by targeting miR-206, NEAT2 has the potential to enhance HG-induced HK-2 pyroptosis. This miR-206 is predicted to be a latent target in the clinical treatment of DN.

An integrated RNA sequencing and network pharmacology approach reveals the molecular mechanism of dapagliflozin in the treatment of diabetic nephropathy

Dapagliflozin, an inhibitor of sodium-glucose cotransporter 2 (SGLT2), is a new type of oral hypoglycemic drugs which can promote glucose excretion in the kidney. Studies have shown that dapagliflozin has renoprotective effect in the treatment of type 2 diabetes. However, the underlying mechanism remains unclear. Here, we combined integrated RNA sequencing and network pharmacology approach to investigate the molecular mechanism of dapagliflozin for diabetic nephropathy (DN). Dapagliflozin significantly relieved glucose intolerance, urinary albumin/creatinine ratio (UACR) and renal pathological injuries of db/db mice. The LncRNA and mRNA expression in kidney tissues from control group (CR), db/db group (DN) and dapagliflozin group (DG) were assessed by RNA sequencing. We identified 7 LncRNAs and 64 mRNAs common differentially expressed in CR vs DN and DN vs DG, which were used to construct co-expression network to reveal significantly correlated expression patterns in DN. In addition, network pharmacology was used to predict the therapeutic targets of dapagliflozin and we constructed component-target-pathway network according to the results of RNA sequencing and network pharmacology. We found that SMAD9, PPARG, CD36, CYP4A12A, CYP4A12B, CASP3, H2-DMB2, MAPK1, MAPK3, C3 and IL-10 might be the pivotal targets of dapagliflozin for treating DN and these genes were mainly enriched in pathways including TGF-β signaling pathway, PPAR signaling pathway, Chemokine signaling pathway, etc. Our results have important implication and provide novel insights into the protective mechanism of dapagliflozin for treating DN.

LINC02381, a sponge of miR-21, weakens osteogenic differentiation of hUC-MSCs through KLF12-mediated Wnt4 transcriptional repression

INTRODUCTION

Human umbilical cord blood-derived MSCs (hUC-MSCs) have the potential to differentiate into osteoblasts. This study investigated the function and potential mechanisms of a novel lncRNA LINC02381 in hUC-MSC osteogenic differentiation.

MATERIALS AND METHODS

hUC-MSCs were maintained in osteogenic differentiation medium. RT-qPCR assay was performed to assess LINC02381 expression. Alizarin Red S (ARS) and alkaline phosphatase (ALP) staining were performed to evaluate osteogenic differentiation. The interaction between miR-21 and LINC0238/KLF12 was determined by luciferase reporter and RNA immunoprecipitation (RIP) assays. Chromatin immunoprecipitation (ChIP) assay was used to confirm the transcriptional regulation of KLF12 on Wnt4 promoter. The nuclear translocation of β-catenin was evaluated using immunofluorescence. hUC-MSCs seeded on Bio-Oss Collagen scaffolds were transplanted into nude mice to assess in vivo osteogenesis. Bone formation was observed by H&E and Masson's trichrome staining. OSX and OPN levels were assessed by immunohistochemistry.

RESULTS

LINC02381 was up-regulated in the clinical samples of osteoporotic patients. However, LINC02381 expression was reduced during osteogenic differentiation of hUC-MSCs. Enforced expression of LINC02381 suppressed the osteogenic differentiation of hUC-MSCs. Mechanistically, LINC02381 sponged miR-21 to enhance KLF12 expression, which led to the inactivation of Wnt/β-catenin signaling pathway. Furthermore, miR-21 mimics or KLF12 silencing counteracted LINC02381-induced inhibition of osteogenic differentiation, whereas IWP-4 (an inhibitor of Wnt pathway) abolished this effect.

CONCLUSION

In summary, LINC02381 repressed osteogenic differentiation of hUS-MSCs through sponging miR-21 to enhance KLF12-mediated inactivation of Wnt/β-catenin pathway, indicating that LINC02381 might be a therapeutic target for osteoporosis.

Blocking REDD1/TXNIP Complex Ameliorates HG-Induced Renal Tubular Epithelial Cell Apoptosis and EMT through Repressing Oxidative Stress

Diabetic nephropathy (DN) has become the most common secondary kidney disease causing end-stage renal disease (ESRD). Nevertheless, the underlying mechanisms responsible for DN remain largely unknown. Regulated in development and DNA damage response 1 (REDD1) is a prooxidative molecule known to contribute to diabetes mellitus and its complications. However, it has not been previously examined whether and how REDD1 can further drive renal tubular epithelial cell (RTEC) apoptosis and epithelial-to-mesenchymal transition in DN. The expression of REDD1 was elevated in the kidneys of DN patients and diabetic mice in this study. By generating the DN model in REDD1 knockout mice, we demonstrated that REDD1 deficiency significantly improved apoptosis and EMT in diabetic mice. In vitro experiments showed that REDD1 generation was induced by high glucose (HG) in HK-2 cells. Similarly, the transfection of REDD1 siRNA plasmid also suppressed HG-induced apoptosis and EMT. Furthermore, we discovered that the inhibition of REDD1 suppressed the expression of Nox4-induced HG and reactive oxygen species (ROS) synthesis in HK-2 cells. In addition, HG could induce endogenous REDD1 and TXNIP to form a powerful complex. In summary, our findings demonstrate that blocking the REDD1/TXNIP complex can prevent HG-induced apoptosis and EMT by inhibiting ROS production, highlighting REDD1 as a valuable therapeutic priority site for DN.

LncRNA MALAT1 Aggravates Renal Tubular Injury via Activating LIN28A and the Nox4/AMPK/mTOR Signaling Axis in Diabetic Nephropathy

BACKGROUND

Diabetic nephropathy (DN) is a serious complication among patients with diabetes. Elucidating its pathogenesis is crucial for identifying novel biomarkers and therapeutic targets for DN.

METHODS

DN tissues were harvested for examining MALAT1, LIN28A and Nox4. Human kidney-2 (HK-2) cells were treated with high glucose (HG) for establishing a cell model of DN. Cell viability was examined by MTT assay. HG-induced cell apoptosis and secretion of TNF-α and IL-6 were analyzed by TUNEL and ELISA assays, respectively. RIP and RNA pull-down assays were applied to analyze the interaction between MALAT1, LIN28A and Nox4 in HK-2 and human embryonic kidney 293T (HEK-293T) cells. A rat model of DN was established to determine the role of MALAT1 in DN in vivo.

RESULTS

MALAT1, LIN28A and Nox4 were upregulated in DN tissues and HG-treated HK-2 cells. Overexpression of MALAT1, LIN28A or Nox4 reduced cell viability and enhanced cell apoptosis, ROS generation and secretion of inflammatory cytokines in HG-treated HK-2 cells, whereas knockdown of MALAT1, LIN28A or Nox4 exerted opposite effects. Furthermore, MALAT1 directly interacted with LIN28A. Moreover, MALAT1 facilitated the interaction between LIN28A and Nox4 to increase Nox4 stability. Knockdown of Nox4 relieved HG-induced injury by suppressing the AMPK/mTOR signaling in HK-2 cells. Knockdown of MALAT1 alleviated renal tubular epithelial injury by suppressing LIN28A and the Nox4/AMPK/TOR signaling in DN.

CONCLUSION

MALAT1 activates the AMPK/mTOR signaling via interacting with LIN28A to stabilize Nox4 mRNA, thereby aggravating high glucose-induced renal tubular epithelial injury. Our findings provide potential therapeutic targets for DN.

LncRNA MALAT1 promotes osteogenic differentiation of BMSCs and inhibits osteoclastic differentiation of Mø in osteoporosis via the miR-124-3p/IGF2BP1/Wnt/β-catenin axis

Osteoporosis is defined as a skeletal disorder characterized by impairment in bone strength. The potential application of lncRNAs as therapeutic targets for osteoporosis has been unveiled. This study investigated the regulatory mechanism of lncRNA MALAT1 in the differentiation of bone marrow stem cells (BMSCs) and macrophages (Mø) in osteoporosis. MALAT1 expression in peripheral blood of elderly osteoporosis patients and healthy volunteers was detected. BMSCs and mononuclear Mø were isolated and cultured. Osteogenic differentiation of BMSCs and osteoclastic differentiation of Mø were induced. BMSCs and Mø were transfected with si-MALAT1, miR-124-3p mimics, miR-124-3p inhibitor, or pcDNA IGF2BP1, followed by detection of cell differentiation. The target microRNAs (miRs) and downstream genes and signaling pathways of MALAT1 were examined. The ovariectomy-induced mouse model of osteoporosis was established, and the mice were injected with pcDNA-MALAT1. MALAT1 was downregulated in osteoporosis patients, increased in BMSCs after osteogenic differentiation, and diminished in Mø after osteoclastic differentiation. Downregulation of MALAT1 repressed osteogenic differentiation of BMSCs and facilitated osteoclastic differentiation of Mø. MALAT1 upregulated IGF2BP1 expression by competitively binding to miR-124-3p. miR-124-3p silencing reversed the effect of si-MALAT1 on BMSCs and Mø differentiation, and IGF2BP1 upregulation averted the effect of overexpressed-miR-124-3p by activating the Wnt/β-catenin pathway. Upregulation of MALAT1 activated the Wnt/β-catenin pathway and attenuated bone injury in mice. In conclusion, lncRNA MALAT1 promoted the osteogenic differentiation of BMSCs and inhibited osteoclastic differentiation of Mø in osteoporosis via the miR-124-3p/IGF2BP1/Wnt/β-catenin axis. This article is protected by copyright. All rights reserved.

CDKN2B-AS1 participates in high glucose-induced apoptosis and fibrosis via NOTCH2 through functioning as a miR-98-5p decoy in human podocytes and renal tubular cells

BACKGROUND

Diabetic nephropathy (DN) is the most common causes of end-stage renal disease. Long non-coding RNA cyclin-dependent kinase inhibitor 2B antisense RNA 1 (CDKN2B-AS1) is connected with the development of DN, but the role of CDKN2B-AS1 in DN has not been entirely elucidated.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was carried out to measure CDKN2B-AS1 and miR-98-5p levels. Cell viability, proliferation, and apoptosis were analyzed with 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) or flow cytometry assays. Protein levels were measured by western blotting. The relationship between CDKN2B-AS1 or notch homolog 2 (NOTCH2) and miR-98-5p was verified via dual-luciferase reporter assay.

RESULTS

CDKN2B-AS1 and NOTCH2 were upregulated in the serum of DN patients and high glucose-disposed human podocytes (HPCs) and human renal tubular cells (HK-2), whereas miR-98-5p was downregulated. High glucose repressed viability and accelerated apoptosis of HPCs and HK-2 cells. CDKN2B-AS1 knockdown impaired high glucose-induced apoptosis and fibrosis of HPCs and HK-2 cells. Mechanistically, CDKN2B-AS1 sponged miR-98-5p to regulate NOTCH2 expression. Also, CDKN2B-AS1 inhibition-mediated effects on apoptosis and fibrosis of high glucose-disposed HPCs and HK-2 cells were weakened by miR-98-5p inhibitor. Also, NOTCH2 knockdown partly reversed miR-98-5p inhibitor-mediated impacts on apoptosis and fibrosis of high glucose-disposed HPCs and HK-2 cells.

CONCLUSION

High glucose-induced CDKN2B-AS1 promoted apoptosis and fibrosis via the TGF-β1 signaling mediated by the miR-98-5p/NOTCH2 axis in HPCs and HK-2 cells.

Transforming Growth Factor-β and Long Non-coding RNA in Renal Inflammation and Fibrosis

Renal fibrosis is one of the most characterized pathological features in chronic kidney disease (CKD). Progressive fibrosis eventually leads to renal failure, leaving dialysis or allograft transplantation the only clinical option for CKD patients. Transforming growth factor-β (TGF-β) is the key mediator in renal fibrosis and is an essential regulator for renal inflammation. Therefore, the general blockade of the pro-fibrotic TGF-β may reduce fibrosis but may risk promoting renal inflammation and other side effects due to the diverse role of TGF-β in kidney diseases. Long non-coding RNAs (lncRNAs) are RNA transcripts with more than 200 nucleotides and have been regarded as promising therapeutic targets for many diseases. This review focuses on the importance of TGF-β and lncRNAs in renal inflammation, fibrogenesis, and the potential applications of TGF-β and lncRNAs as the therapeutic targets and biomarkers in renal fibrosis and CKD are highlighted.

lncRNA‑MALAT1 promotes high glucose‑induced H9C2 cardiomyocyte pyroptosis by downregulating miR‑141‑3p expression

Diabetic cardiomyopathy (DCM) is caused by diabetes and can result in heart failure. Long non-coding RNAs (lncRNAs) have been demonstrated to be closely associated with DCM development. The present study aimed to investigate whether lncRNA-metastasis-associated lung adenocarcinoma transcript-1 (MALAT1) altered high glucose (HG)-induced H9C2 cardiomyocyte pyroptosis by targeting microRNA (miR)-141-3p. H9C2 cells were treated with normal glucose (NG) or HG. lncRNA-MALAT1 and miR-141-3p expression levels were determined via reverse transcription-quantitative PCR (RT-qPCR). MALAT1 and miR-141-3p knockdown and overexpression were established and confirmed via RT-qPCR. The association between MALAT1 expression and miR-141-3p expression, as well as the induction of pyroptosis and gasdermin D (GSDMD)-N expression were evaluated by performing dual luciferase reporter, TUNEL staining and immunofluorescence staining assays, respectively. Western blotting was conducted to measure the expression levels of pyroptosis-associated proteins, including apoptosis-associated speck-like protein, GSDMD-N, caspase-1, nucleotide oligomerization domain-like receptor protein 3 and GSDMD. MALAT1 mRNA expression levels were significantly increased, whereas miR-141-3p expression levels were significantly decreased in HG-treated H9C2 cells compared with the NG group. Compared with the HG group, MALAT1 overexpression significantly reduced miR-141-3p expression levels, increased the rate of TUNEL positive cells and upregulated the expression levels of pyroptosis-associated proteins. MALAT1 knockdown displayed the opposite effect on the rate of TUNEL positive cells and the expression levels of pyroptosis-associated proteins. Furthermore, the rate of TUNEL positive cells, and GSDMD-N and pyroptosis-associated protein expression levels were significantly reduced by miR-141-3p overexpression in MALAT1-overexpression H9C2 cells. The results indicated that compared with NG treatment, HG treatment increased MALAT1 expression levels and decreased miR-141-3p expression levels in H9C2 cells. Therefore, the present study suggested that lncRNA-MALAT1 targeted miR-141-3p to promote HG-induced H9C2 cardiomyocyte pyroptosis.

Non-Coding RNAs as Biomarkers and Therapeutic Targets for Diabetic Kidney Disease

Diabetic kidney disease (DKD) is the most common diabetic complication and is a leading cause of end-stage kidney disease. Increasing evidence shows that DKD is regulated not only by many classical signaling pathways but also by epigenetic mechanisms involving chromatin histone modifications, DNA methylation, and non-coding RNA (ncRNAs). In this review, we focus on our current understanding of the role and mechanisms of ncRNAs, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) in the pathogenesis of DKD. Of them, the regulatory role of TGF-β/Smad3-dependent miRNAs and lncRNAs in DKD is highlighted. Importantly, miRNAs and lncRNAs as biomarkers and therapeutic targets for DKD are also described, and the perspective of ncRNAs as a novel therapeutic approach for combating diabetic nephropathy is also discussed.

Knockdown of the Long Noncoding RNA LUCAT1 Inhibits High-Glucose-Induced Epithelial-Mesenchymal Transition through the miR-199a-5p-ZEB1 Axis in Human Renal Tubular Epithelial Cells

Renal fibrosis, the leading cause of end-stage renal disease and in which epithelial-mesenchymal transition (EMT) plays a central role, has a complex pathogenesis that is not fully understood. Therefore, we investigated the role of the long noncoding RNA LUCAT1 in the EMT of renal tubular epithelial cells under high-glucose (HG) conditions and the underlying mechanism involved. In this study, we established HG and normal glucose groups of HK-2 cells by treating HK-2 cells 30.0 or 5.5 mmol/L glucose, respectively. To investigate the roles of LUCAT1 and miR-199a-5p in HG-induced EMT, we transfected the HG group with negative control small interfering RNA (siRNA), siRNA targeting LUCAT1, negative control microRNA, or an miR-199a-5p mimic. The results of the quantitative reverse transcription PCR indicated that the LUCAT1 level in the HG group was increased, whereas the miR-199a-5p level was decreased. The EMT in the cells was induced by treatment with HG but was weakened by LUCAT1 knockdown or miR-199a-5p overexpression, which both also inhibited the HG-induced phosphorylation of SMAD3. Moreover, LUCAT1 and ZEB1 mRNA comprised the same microRNA response elements of miR-199a-5p. LUCAT1 knockdown had no effect on the miR-199a-5p level but decreased the HG-induced upregulation of ZEB1. In conclusion, HG conditions induced the upregulation of LUCAT1, and LUCAT1 knockdown inhibited the EMT in HG-treated HK-2 cells. LUCAT1 likely promotes HG-induced EMT through ZEB1 by sponging miR-199a-5p.

HOXC-AS2 mediates the proliferation, apoptosis, and migration of non-small cell lung cancer by combining with HOXC13 gene

Non-small cell lung cancer (NSCLC) is the highest incidence and mortality of malignant tumors worldwide and has become a global public health problem. Long non-coding RNAs (LncRNAs) are expected to participate in the progression of NSCLC. This study aims to explore the effects and underlying mechanisms of LncRNA HOXC-AS2 on NSCLC cell proliferation, apoptosis, and migration. The Cell Counting Kit-8 (CCK-8) and clone formation assay were used to measure the A549 and HCC827 cell proliferation. The cell apoptosis and migration was respectively analyzed by flow cytometry and transwell assay. RNA immunoprecipitation (RIP) was used to detect the interaction between HOXC-AS2 and HOXC13. The expression of β-catenin, α-SMA, MMP-1, MMP-2 expression, E-cadherin, and Ki-67 expression were determined by Western blot or immunohistochemistry (IHC) assay. We found that HOXC-AS2 was significantly up-regulated in NSCLC tissues. Knockdown of HOXC-AS2 expression resulted in significant decreases in NSCLC cell proliferation, migration, and epithelial-mesenchymal transition (EMT) process marker proteins, simultaneously activated A549 and HCC827 cell apoptosis. RIP assay suggested that HOXC13 was a functional target for HOXC-AS2. And HOXC-AS2 and HOXC13 could positively regulate each other. Compared with the normal tissues, the mRNA level of HOXC13 was increased in NSCLC tissues. HOXC13 silencing counteracted increases of A549 and HCC827 cell proliferation and migration, as well as a decrease of cell apoptosis induced by HOXC-AS2 overexpression. Moreover, HOXC-AS2 silencing reduced tumor growth rate and Ki-67 expression in vivo. Taken together, HOXC-AS2 knockdown inhibited NSCLC cell proliferation and migration, as well as stimulated NSCLC cell apoptosis through regulation of HOXC13 expression.

CircHIPK3 Alleviates High Glucose Toxicity to Human Renal Tubular Epithelial HK-2 Cells Through Regulation of miR-326/miR-487a-3p/SIRT1

BACKGROUND

The intervention of circular RNA HIPK3 (circHIPK3) in diabetes has drawn increasing attention in recent years. However, the underlying mechanism of circHIPK3 in diabetic nephropathy (DN) has not been fully elucidated. Thus, the current study aims to investigate the role of circHIPK3 in high glucose (HG)-induced toxicity to human renal tubular epithelial HK-2 cells.

METHODS

The expression of circHIPK3 in HK-2 cells induced by HG was determined by qRT-PCR and Western blot. The regulatory effects of circHIPK3 and miR-326/miR-487a-3p on cells proliferative and apoptosis were evaluated by CCK-8 and flow cytometry. Dual-luciferase reporter assay was applied to predict the target genes of miR-326 or miR-487a-3p.

RESULTS

Expression level of circHIPK3 in HK-2 cells was remarkably decreased after the treatment of HG. The overexpression of circHIPK3 effectively reversed the HG-induced HK-2 cell proliferation inhibition and apoptosis. Furthermore, SIRT1 was confirmed to be the target gene of miR-326 and miR-487a-3p, which were showed to be the downstream genes of circHIPK3. The silencing of miR-326 or miR-487a-3p was also proved to induce proliferation and reduce apoptosis in HG-induced HK-2 cells.

CONCLUSION

Our data suggest that overexpression of circHIPK3 can attenuate the proliferation inhibition of HK-2 induced by HG and inhibit apoptosis through sponging miR-326 or miR-487a-3p to regulate SIRT1.

LncRNA PVT1 Regulates High Glucose-Induced Viability, Oxidative Stress, Fibrosis, and Inflammation in Diabetic Nephropathy via miR-325-3p/Snail1 Axis

BACKGROUND

Diabetic nephropathy (DN), as a complication of diabetes, is a leading cause of mortality in diabetic patients. It has been reported that lncRNA PVT1 (PVT1) could accelerate the progression of DN by promoting ECM accumulation and increasing the expression of fibronectin 1 (FN1). However, the underlying mechanism of PVT1 on DN remains unknown.

METHODS

To study the effect of PVT1 on DN, mice were injected 50 mg/kg STZ to build the DN models. Mesangial cells (MCs) were induced by high glucose as in vitro model of DN. The expression level of PVT1, miR-325-3 and Snail1 was assessed by qRT-PCR and Western blot. Luciferase reporter assay, RNA pull-down and RIP were used to explore the interaction among PVT1, miR-325-3 and Snail1.

RESULTS

In in vivo and in vitro DN models, the expression of PVT1 was upregulated. High glucose (HG) induced cell viability, oxidative stress, fibrosis and inflammation in MCs, which were reversed in the PVT1-KD MCs. The level of miR-325-3p was also increased in in vivo and in vitro experiments. Additionally, PVT1 can directly bind to miR-325-3p. Finally, Snail1 was a direct target of miR-325-3p.

CONCLUSION

PVT1 inhibits viability, oxidative stress, fibrosis, and inflammation in DN via miR-325-3p/Snail1 axis.

Emerging Roles of Long Non-Coding RNAs in Renal Fibrosis

Renal fibrosis is an unavoidable consequence that occurs in nearly all of the nephropathies. It is characterized by a superabundant deposition and accumulation of extracellular matrix (ECM). All compartments in the kidney can be affected, including interstitium, glomeruli, vasculature, and other connective tissue, during the pathogenesis of renal fibrosis. The development of this process eventually causes destruction of renal parenchyma and end-stage renal failure, which is a devastating disease that requires renal replacement therapies. Recently, long non-coding RNAs (lncRNAs) have been emerging as key regulators governing gene expression and affecting various biological processes. These versatile roles include transcriptional regulation, organization of nuclear domains, and the regulation of RNA molecules or proteins. Current evidence proposes the involvement of lncRNAs in the pathologic process of kidney fibrosis. In this review, the biological relevance of lncRNAs in renal fibrosis will be clarified as important novel regulators and potential therapeutic targets. The biology, and subsequently the current understanding, of lncRNAs in renal fibrosis are demonstrated—highlighting the involvement of lncRNAs in kidney cell function, phenotype transition, and vascular damage and rarefaction. Finally, we discuss challenges and future prospects of lncRNAs in diagnostic markers and potential therapeutic targets, hoping to further inspire the management of renal fibrosis.

Responses of oxidative stress and inflammatory cytokines after zearalenone exposure in human kidney cells

Zearalenone is a mycotoxin widely found worldwide that is produced by several fungal species. Due to its similarity to estradiol, it has been shown to have toxic effects on the reproductive system. Although various animal studies have been conducted to investigate the toxic effects of zearalenone, the mechanisms of toxicity have not been fully elucidated. The aim of the study was to investigate the dose-dependent toxic effects of zearalenone exposure in human kidney cells. The half-maximal inhibitory concentration values of zearalenone in HK-2 cells were found to be 133.42 and 101.74 µM in MTT- and NRU-tests, respectively. Zearalenone exposure at concentrations of 1, 10 and 50 µM decreased cell proliferation by 2.1, 11.07 and 24.34%, respectively. Reactive oxygen species levels increased significantly in a dose-dependent manner. A significant increase was observed in the expressions of MGMT, α-GST, Hsp70 and HO-1 genes, which are associated with oxidative damage, while a significant decrease in L-Fabp gene expression was observed. Moreover, zearalenone increased gene expression of inflammatory cytokines, such as IL-6, IL-8, TNFα and MAPK8. Significant increases were observed at the level of global DNA methylation and expression of DNMT1 in all exposure groups. These results indicate that changes in DNA methylation and oxidative damage may play an important role in the toxicity of zearalenone.

LncRNA SNHG16 induces proliferation and fibrogenesis via modulating miR-141-3p and CCND1 in diabetic nephropathy

LncRNAs are reported to participate in the progression of various diseases including diabetic nephropathy. Currently, we reported that SNHG16 was obviously upregulated in db/db mice and high glucose-treated mice mesangial cells. Then, functional experiments showed that SNHG16 silencing significantly inhibited proliferation of mice mesangial cells, which induced the apoptosis and triggered cell cycle arrest. Meanwhile, proliferation-related biomarkers PCNA and Cyclin D1 (CCND1) were greatly repressed. Furthermore, western blot analysis was conducted to test fibrogenesis-associated genes Fibronectin and α-SMA. Meanwhile, the increased protein expression levels of Fibronectin and α-SMA under high glucose conditions were reversed by loss of SNHG16. miR-141-3p has been reported to be involved in various diseases. Then, RNA immunoprecipitation assay revealed the relation between SNHG16 and miR-141-3p. Downregulation of SNHG16 was able to induce expression of miR-141-3p, which was obviously reduced in db/db diabetic nephropathy mice. In addition, CCND1 is a crucial cell cycle master in human diseases. CCND1 was speculated as the target of miR-141-3p and miR-141-3p inhibited CCND1 expression significantly. Meanwhile, we observed that loss of CCND1 greatly repressed mice mesangial cell proliferation and induced cell apoptosis. Taken these together, we revealed for the first time that SNHG16 induced proliferation and fibrogenesis via modulating miR-141-3p and CCND1 in diabetic nephropathy. SNHG16/miR-141-3p/CCND1 axis can suggest a pathological mechanism of progression of diabetic nephropathy.

A bioinformatics and network pharmacology approach to the mechanisms of action of Shenxiao decoction for the treatment of diabetic nephropathy

BACKGROUND

The epithelial-to-mesenchymal transition (EMT) of renal tubular epithelial cells is the main pathological alteration in diabetic nephropathy (DN). Traditional Chinese medicine (TCM) has been used for the treatment of DN in clinical practice and has been proven to be effective.

PURPOSE

This aim of this study was to shed light on the efficacy of Shenxiao decoction (SXD) on the EMT of renal tubular epithelial cells and the molecular mechanisms of SXD in mice with DN, as well as on the high glucose (HG)- and TGF-β1-induced EMT of NRK-52E and HK-2 cells.

STUDY DESIGN AND METHODS

A bioinformatics and network pharmacology method were utilized to construct the active ingredient-target networks of SXD that were responsible for the beneficial effects against DN. The effects of RUNX3 were validated in HG- and TGF-β1-induced EMT processes in NRK-52E and HK-2 cells.

RESULTS

Bioinformatics analysis revealed that 122 matching targets were closely associated with the regulation of cell migration and the AGE-RAGE signaling pathway in diabetic complications. The results also revealed that, relative to the mice with DN, the mice in the treatment group had an improved general state and reduced blood glucose levels. The degradation of renal function was ameliorated by SXD. Moreover, the protective effects of SXD were also observed on renal structural changes. Furthermore, SXD suppressed the activation of the transforming growth factor (TGF)-β1/Smad pathway and upregulated the RUNX3 and E-cadherin levels and downregulated the extracellular matrix (ECM) protein levels in mice with DN. SXD was further found to prevent the HG- and TGF-β1-induced EMT processes in NRK-52E and HK-2 cells. Additionally, the overexpression of RUNX3 markedly inhibited the EMT and TGF-β1/Smad pathway induced by HG and TGF-β1 in NRK-52E and HK-2 cells.

CONCLUSION

Taken together, these results suggest that SXD maybe alleviate EMT in DN via the inhibition of the TGF-β1/Smad/RUNX3 signaling pathway under hyperglycemic conditions.