scholarly journals LncRNA NNT-AS1 regulates proliferation, ECM accumulation and inflammation of human mesangial cells induced by high glucose through miR-214-5p/smad4

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Zhuang Geng ◽  
Xiang Wang ◽  
Shiyuan Hao ◽  
Bingzi Dong ◽  
Yajing Huang ◽  
...  

Abstract Background LncRNA NNT-AS1 (NNT-AS1) has been extensively studied as the causative agent in propagation and progression of lung and bladder cancers, and cholangiocarcinoma. However, its significance in proliferation and inflammation of diabetic nephropathy is enigmatic. This study focuses on the molecular mechanisms followed by NNT-AS1 to establish diabetic nephropathy (DN) and its potential miRNA target. Methods Bioinformatics analysis to identify potential miRNA target of NNT-AS1 and smad4 transcription factor was conducted using LncBase and TargetScan, and was subsequently confirmed by luciferase reporter assay. Relative quantitative expression of NNT-AS1 in human glomerular mesangial cells (HGMCs) was detected through quantitative real-time PCR and WB analysis. Cell proliferation was detected through CCK-8 assay, whereas, ELISA was conducted to evaluate the expression of inflammatory cytokines. Following this, relative expression of miR-214-5p and smad4 were confirmed through qRT-PCR and western blot analysis. Results Results from the experiments manifested up-regulated levels of NNT-AS1 and smad4 in the blood samples of DN patients as well as in HGMCs, whereas, downregulated levels of miR-214-5p were measured in the HGMCs suggesting the negative correlation between NNT-AS1 and miR-214-5p. Potential binding sites of NNT-AS1 showed miR-214-5p as its direct target and NNT-AS1 as potential absorber for this microRNA, in turn increasing the expression of transcription factor smad4. Conclusion The data suggests that NNT-AS1 can be positively used as a potential biomarker and indicator of DN and causes extracellular matrix (ECM) accumulation and inflammation of human mesangial cells.

2020 ◽  
Vol 45 (4) ◽  
pp. 589-602 ◽  
Author(s):  
Jin-Feng Zhan ◽  
Hong-Wei Huang ◽  
Chong Huang ◽  
Li-Li Hu ◽  
Wen-Wei Xu

Introduction: Diabetic nephropathy (DN) is a serious complication of diabetes mellitus and is considered to be a sterile inflammatory disease. Increasing evidence suggest that pyroptosis and subsequent inflammatory response play a key role in the pathogenesis of DN. However, the underlying cellular and molecular mechanisms responsible for pyroptosis in DN are largely unknown. Methods: The rat models of DN were successfully established by single 65 mg/kg streptozotocin treatment. Glomerular mesangial cells were exposed to 30 mmol/L high glucose media for 48 h to mimic the DN environment in vitro. Gene and protein expressions were determined by quantitative real-time PCR and Western blot. Cell viability and pyroptosis were measured by MTT assay and flow cytometry analysis, respectively. The relationship between lncRNA NEAT1, miR-34c, and Nod-like receptor protein-3 (NLRP3) was confirmed by luciferase reporter assay. Results: We found that upregulation of NEAT1 was associated with the increase of pyroptosis in DN models. miR-34c, as a target gene of NEAT1, mediated the effect of NEAT1 on pyroptosis in DN by regulating the expression of NLRP3 as well as the expressions of caspase-1 and interleukin-1β. Either miR-34c inhibition or NLRP3 overexpression could reverse the accentuation of pyroptosis and inflammation by sh-NEAT1 transfection in the in vitro model of DN. Conclusions: Our findings suggested NEAT1 and its target gene miR-34c regulated cell pyroptosis via mediating NLRP3 in DN, providing new insights into understanding the molecular mechanisms of pyroptosis in the pathogenesis of DN.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Le Zhang ◽  
Qian Dai ◽  
Lanlan Hu ◽  
Hua Yu ◽  
Jing Qiu ◽  
...  

Purpose. Hyperoside, a flavonoid isolated from conventional medicinal herbs, has been demonstrated to exert a significant protective effect in diabetic nephropathy. This study aimed to determine the underlying mechanisms, by which hyperoside inhibits high glucose-(HG-) induced proliferation in mouse renal mesangial cells. Methods. Mouse glomerular mesangial cells line (SV40-MES13) was used to study the inhibitory effect of hyperoside on cell proliferation induced by 30 mM glucose, which was used to simulate a diabetic condition. Viable cell count was assessed using the Cell Counting Kit-8 and by the 5-ethynyl-20-deoxyuridine incorporation assay. The underlying mechanism involving miRNA-34a was further investigated by quantitative RT-PCR and transfection with miRNA-34a agomir. The phosphorylation levels of extracellular signal-regulated kinases (ERKs) and cAMP-response element-binding protein (CREB) were measured by Western blotting. The binding region and the critical binding sites of CREB in the miRNA-34a promoter were investigated by the chromatin immunoprecipitation assay and luciferase reporter assay, respectively. Results. We found that hyperoside could significantly decrease HG-induced proliferation of SV40-MES13 cells in a dose-dependent manner, without causing obvious cell death. In addition, hyperoside inhibited the activation of ERK pathway and phosphorylation of its downstream transcriptional factor CREB, as well as the miRNA-34a expression. We further confirmed that CREB-mediated regulation of miRNA-34a is dependent on the direct binding to specific sites in the promoter region of miRNA-34a. Conclusion. Our cumulative results suggested that hyperoside inhibits the proliferation of SV40-MES13 cells through the suppression of the ERK/CREB/miRNA-34a signaling pathway, which provides new insight to the current investigation on therapeutic strategies for diabetic nephropathy.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Li Zhao ◽  
Huaqian Chen ◽  
Lin Wu ◽  
Zhengdong Li ◽  
Ren Zhang ◽  
...  

Abstract Background Long non-coding RNAs (lncRNAs) have been reported to play vital roles in diabetic nephropathy (DN). The aim of this study was to explore the function of mechanism of lncRNA KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1) in DN. Methods DN cell models were established using high glucose (HG) treatment in human glomerular mesangial cells (HGMC) and human renal glomerular endothelial cells (HRGEC). The expression levels of KCNQ1OT1, microRNA-93-5p (miR-93-5p), and Rho associated coiled-coil containing protein kinase 2 (ROCK2) mRNA was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell Counting Kit-8 (CCK-8) assay and flow cytometry were used to detect cell proliferation and apoptosis, respectively. ROCK2 and apoptosis/fibrosis-related protein levels were examined by western blot. The predicted interaction between miR-93-5p and KCNQ1OT1 or ROCK2 was verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Results KCNQ1OT1 was upregulated in DN patients and DN cell models. KCNQ1OT1 knockdown inhibited cell proliferation and fibrosis and induced apoptosis in DN cell models. MiR-93-5p was a direct target of KCNQ1OT1, and miR-93-5p inhibition restored the KCNQ1OT1 knockdown-mediated effects on cell proliferation, fibrosis and apoptosis in DN cell models. In addition, ROCK2 was identified as a target of miR-93-5p, and miR-93-5p overexpression suppressed cell proliferation and fibrosis and accelerated apoptosis by targeting ROCK2 in DN cell models. Moreover, KCNQ1OT1 regulated ROCK2 expression by binding to miR-93-5p. Conclusion KCNQ1OT1 knockdown inhibited cell proliferation and fibrosis and induced apoptosis in DN by regulating miR-93-5p/ROCK2 axis, providing potential value for the treatment of DN.


2016 ◽  
Vol 57 (4) ◽  
pp. 233-249 ◽  
Author(s):  
Xuhua Mi ◽  
Wanxin Tang ◽  
Xiaolei Chen ◽  
Fei Liu ◽  
Xiaohong Tang

Extracellular matrix (ECM) increase in diabetic nephropathy (DN) is closely related to mitochondrial dysfunction. The mechanism of protective function of mitofusin 2 (Mfn2) for mitochondria remains largely unknown. In this study, the molecular mechanisms for the effect of Mfn2 on mitochondria and subsequent collagen IV expression in DN were investigated. Ras-binding-deficient mitofusin 2 (Mfn2–Ras(Δ)) were overexpressed in rat glomerular mesangial cells, and then the cells were detected for mitochondrial morphology, cellular reactive oxygen species (ROS), mRNA and protein expression of collagen IV with advanced glycation end-product (AGE) stimulation. Preliminary results reveal that the mitochondrial dysfunction and the increased synthesis of collagen IV after AGE stimulation were reverted by Mfn2–Ras(Δ) overexpression. Bioinformatical computations were performed to search transcriptional factor motifs in the promoter region of collagen IV. Three specific regions for TFAP2A binding were identified, followed by validation with chromatin immunoprecipitation experiments. Knocking down TFAP2A significantly decreased the TF binding in the first two regions and the gene expression of collagen IV. Furthermore, results reveal that Mfn2–Ras(Δ) overexpression significantly mitigated TFAP2A binding and also reverted the histone acetylation at Regions 1 and 2 after AGE stimulation. In streptozotocin-induced diabetic rats, Mfn2–Ras(Δ) overexpression also ameliorated glomerular mesangial lesions with decreased collagen IV expression, accompanied by decreased acetylation and TFAP2A binding at Region 1. In conclusion, this study highlights the pathway by which mitochondria affect the histone acetylation of gene promoter and provides a new potential therapy approach for DN.


2004 ◽  
Vol 17 (3) ◽  
pp. 271-282 ◽  
Author(s):  
Jolean Morrison ◽  
Kristen Knoll ◽  
Martin J. Hessner ◽  
Mingyu Liang

Pathological alterations in glomerular mesangial cells play a critical role in the development of diabetic nephropathy, the leading cause of end-stage renal disease. Molecular mechanisms mediating such alterations, however, remain to be fully understood. The present study first examined the effect of high glucose on the mRNA expression profile in rat mesangial cells using cDNA microarray. Based on variation-weighted criteria and with a false discovery rate of 4.3%, 459 of 17,664 cDNA elements examined were found to be upregulated and 151 downregulated by exposure to 25 mM d-glucose for 5 days. A large number of differentially expressed genes belonged to several functional categories, indicating high glucose had a profound effect on mesangial cell proliferation, protein synthesis, energy metabolism, and, somewhat unexpectedly, protein sorting and the cytoskeleton. Interestingly, several thiol antioxidative genes (glutathione peroxidase 1, peroxiredoxin 6, and thioredoxin 2) were found by microarray and confirmed by real-time PCR to be upregulated by high glucose. These changes suggested that the oxidative stress known to be induced in mesangial cells by high glucose might be buffered by upregulation of the thiol antioxidative pathway. Upregulation of thiol antioxidative genes also occurred in high-glucose-treated human mesangial cells and in glomeruli isolated from rats after 1 wk of streptozotocin-induced diabetes, but not in human proximal tubule cells. High glucose slightly increased lipid peroxidation and decreased the amount of reduced thiols in rat and human mesangial cells. Disruption of the thiol antioxidative pathway by two different thiol-oxidizing agents resulted in a three- to fivefold increase in high-glucose-induced lipid peroxidation. In summary, the present study provided a global view of the short-term effect of high glucose on mesangial cells at the level of mRNA expression and identified the upregulation of the thiol antioxidative pathway as an adaptational response of mesangial cells to high glucose.


2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Rekha Singh

Ang II is shown to mediate the stimulatory effect of high glucose on TGF-b1 and extracellular matrix proteins in glomerular mesangial cells. Also inhibition of Ang II formation in cell media (extracellular) and lysates (intracellular) blocks high-glucose effects on TGF-b1 and matrix more effectively compared to inhibition of extracellular Ang II alone. To investigate whether intracellular Ang II can stimulate TGF-b1 and matrix independent of extracellular Ang II, cultured human mesangial cells were transfected with Ang II to increase intracellular Ang II levels and its effects on TGF-b1 and matrix proteins were determined. Prior to transfection, cells were treated with candesartan to block extracellular Ang II-induced responses via cell membrane AT1 receptors. Transfection of cells with Ang II resulted in increased levels of intracellular Ang II which was accompanied by increased production of TGF-b1, collagen IV, fibronectin, and cell proliferation as well. On further examination, intracellular Ang II was found to activate Stat3 transcription factor including increased Stat3 protein expression, tyrosine 705 phosphorylation, and DNA-binding activity. Treatment with AG-490, an inhibitor of Jak2, did not block intracellular Ang II-induced Stat3 phosphorylation at tyrosine 705 residue indicating a Jak2-independent mechanism used by intracellular Ang II for Stat3 phosphorylation. In contrast, extracellular Ang II-induced tyrosine 705 phosphorylation of Stat3 was inhibited by AG-490 confirming the presence of a Jak2-dependent pathway. These findings suggest that intracellular Ang II increases TGF-b1 and matrix in human mesangial cells and also activates Stat3 transcription factor without involvement of the extracellular Ang II signaling pathway.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Jie Yun ◽  
Jinyu Ren ◽  
Yufei Liu ◽  
Lijuan Dai ◽  
Liqun Song ◽  
...  

Abstract Background Circular RNAs (circRNAs) have been considered as pivotal biomarkers in Diabetic nephropathy (DN). CircRNA ARP2 actin-related protein 2 homolog (circ-ACTR2) could promote the HG-induced cell injury in DN. However, how circ-ACTR2 acts in DN is still unclear. This study aimed to explore the molecular mechanism of circ-ACTR2 in DN progression, intending to provide support for the diagnostic and therapeutic potentials of circ-ACTR2 in DN. Methods RNA expression analysis was conducted by the quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Cell growth was measured via Cell Counting Kit-8 and EdU assays. Inflammatory response was assessed by Enzyme-linked immunosorbent assay. The protein detection was performed via western blot. Oxidative stress was evaluated by the commercial kits. The molecular interaction was affirmed through dual-luciferase reporter and RNA immunoprecipitation assays. Results Circ-ACTR2 level was upregulated in DN samples and high glucose (HG)-treated human renal mesangial cells (HRMCs). Silencing the circ-ACTR2 expression partly abolished the HG-induced cell proliferation, inflammation and extracellular matrix accumulation and oxidative stress in HRMCs. Circ-ACTR2 was confirmed as a sponge for miR-205-5p. Circ-ACTR2 regulated the effects of HG on HRMCs by targeting miR-205-5p. MiR-205-5p directly targeted high-mobility group AT-hook 2 (HMGA2), and HMGA2 downregulation also protected against cell injury in HG-treated HRMCs. HG-mediated cell dysfunction was repressed by miR-205-5p/HMGA2 axis. Moreover, circ-ACTR2 increased the expression of HMGA2 through the sponge effect on miR-205-5p in HG-treated HRMCs. Conclusion All data have manifested that circ-ACTR2 contributed to the HG-induced DN progression in HRMCs by the mediation of miR-205-5p/HMGA2 axis.


2021 ◽  
Vol 20 ◽  
pp. 153303382097752
Author(s):  
Ronghua Wang ◽  
Xiuyun Wang ◽  
Jingtao Zhang ◽  
Yanpei Liu

Background: Long non-coding RNAs (lncRNAs) have been reported to play important roles in the progression of human cancers. Herein, bioinformatic analysis identified that LINC00942 was a highly overexpressed lncRNA in lung adenocarcinoma (LUAD). The present study aimed to explore the roles and possible molecular mechanisms of LINC00942 in LUAD. Methods: First, on the basis of TCGA database, the expression and prognosis of LINC00942 were analyzed in LUAD tissues. Then, si-LINC00942 was transfected into A549 and H1299 cells to knockdown the expression of LINC00942. Cell viability was detected by MTT assay. Flow cytometry was used to analyze cell apoptosis. The expressions of PCNA, Bax, Bcl-2, and wnt/β-catenin pathway proteins were detected by western blotting. Dual-luciferase reporter assay was used to evaluate the regulatory relationship between LINC00942 and miR-5006-5p, or miR-5006-5p and FZD1. Results: We discovered that LINC00942 was up-regulated in LUAD tissues compared with adjacent tissues. Besides, we found the increased LINC00942 expression was associated with poor survival. In addition, silencing of LINC00942 suppressed the proliferation, migration, invasion and facilitated the apoptosis of A549 and H1299 cells. Moreover, silencing of LINC00942 repressed the expression of PCNA, Bcl-2, and enhanced Bax expression in A549 and H1299 cells. Mechanically, LINC00942 exerted its effects via enhancing Wnt signaling. LINC00942 functioned as competing endogenous RNA (ceRNA) by binding to miR-5006-5p, upregulating the expression of FZD1, which was a direct target of miR-5006-5p. Conclusion: Our findings indicated that LINC00942/miR-5006-5p/FZD1 axis played important roles in LUAD growth through enhancing Wnt signaling. LINC00942/miR-5006-5p/FZD1 axis might serve as a potential biomarker and therapeutic target for LUAD treatment.


2002 ◽  
Vol 366 (3) ◽  
pp. 807-816 ◽  
Author(s):  
Sunfa CHENG ◽  
Maria Alexandra ALFONSO-JAUME ◽  
Peter R. MERTENS ◽  
David H. LOVETT

Gelatinase A transcriptional regulation is the consequence of combinatorial interactions with key promoter and enhancer elements identified within this gene. A potent 40bp enhancer response element, RE-1, located in the near 5′ flanking regions of the rat and human gelatinase A genes drives high-level expression in glomerular mesangial cells (MCs). Southwestern-blot analysis of MC nuclear extracts revealed specific interactions of RE-1 with at least four proteins, of which three have been identified as p53, activator protein 2 and the single-stranded DNA-binding factor Y-box protein-1 (YB-1). In the present study, we report the identification of a fourth 17kDa RE-1-binding protein as the rat homologue (nm23-β) of the human nm23-H1 metastasis suppressor gene. Recombinant nm23-β protein bound only the single-stranded forms of the RE-1 sequence. Mutagenesis revealed direct interaction of nm23-β with a repeat sequence, 5′-GGGTTT-3′, shown previously to specifically interact with YB-1 [Mertens, Harendza, Pollock and Lovett (1997) J. Biol. Chem. 272, 22905—22912], and recombinant nm23-β protein competed for single-stranded YB-1 binding. Transient transfection of MC with an nm23-β expression plasmid within the context of a RE-1/simian virus 40 promoter/luciferase reporter yielded a concentration-dependent repression (80—90%) of luciferase activity in MC and Rat1 fibroblasts. A similar pattern of nm23-β repression was demonstrated within the context of the RE-1/homologous gelatinase A promoter. Co-transfection of nm23-β blocked YB-1-mediated activation of transcription and expression of gelatinase A. Nm23-β may be an important physiological regulator of gelatinase A transcription that acts by competitive interference with the single-stranded transactivator YB-1. Gelatinase A is a key mediator of tumour metastasis, suggesting that competitive suppression of transcription by nm23-β (or the human nm23-H1) may be a component of the reduced metastatic capabilities of cells expressing high levels of this protein.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Hong Feng ◽  
Junling Gu ◽  
Fang Gou ◽  
Wei Huang ◽  
Chenlin Gao ◽  
...  

While inflammation is considered a central component in the development in diabetic nephropathy, the mechanism remains unclear. The NLRP3 inflammasome acts as both a sensor and a regulator of the inflammatory response. The NLRP3 inflammasome responds to exogenous and endogenous danger signals, resulting in cleavage of procaspase-1 and activation of cytokines IL-1β, IL-18, and IL-33, ultimately triggering an inflammatory cascade reaction. This study observed the expression of NLRP3 inflammasome signaling stimulated by high glucose, lipopolysaccharide, and reactive oxygen species (ROS) inhibitor N-acetyl-L-cysteine in glomerular mesangial cells, aiming to elucidate the mechanism by which the NLRP3 inflammasome signaling pathway may contribute to diabetic nephropathy. We found that the expression of thioredoxin-interacting protein (TXNIP), NLRP3, and IL-1βwas observed by immunohistochemistry in vivo. Simultaneously, the mRNA and protein levels of TXNIP, NLRP3, procaspase-1, and IL-1βwere significantly induced by high glucose concentration and lipopolysaccharide in a dose-dependent and time-dependent manner in vitro. This induction by both high glucose and lipopolysaccharide was significantly inhibited by N-acetyl-L-cysteine. Our results firstly reveal that high glucose and lipopolysaccharide activate ROS/TXNIP/ NLRP3/IL-1βinflammasome signaling in glomerular mesangial cells, suggesting a mechanism by which inflammation may contribute to the development of diabetic nephropathy.


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