scholarly journals METTL14 aggravates podocyte injury and glomerulopathy progression through N6-methyladenosine-dependent downregulating of Sirt1

2021 ◽  
Vol 12 (10) ◽  
Author(s):  
Zhihui Lu ◽  
Hong Liu ◽  
Nana Song ◽  
Yiran Liang ◽  
Jiaming Zhu ◽  
...  

AbstractPodocytes are known to play a determining role in the progression of proteinuric kidney disease. N6-methyladenosine (m6A), as the most abundant chemical modification in eukaryotic mRNA, has been reported to participate in various pathological processes. However, its role in podocyte injury remains unclear. In this study, we observed the elevated m6A RNA levels and the most upregulated METTL14 expression in kidneys of mice with adriamycin (ADR) and diabetic nephropathy. METTL14 was also evidently increased in renal biopsy samples from patients with focal segmental glomerulosclerosis (FSGS) and diabetic nephropathy and in cultured human podocytes with ADR or advanced glycation end product (AGE) treatment in vitro. Functionally, we generated mice with podocyte-specific METTL14 deletion, and identified METTL14 knockout in podocytes improved glomerular function and alleviated podocyte injury, characterized by activation of autophagy and inhibition of apoptosis and inflammation, in mice with ADR nephropathy. Similar to the results in vivo, knockdown of METTL14 facilitated autophagy and alleviated apoptosis and inflammation in podocytes under ADR or AGE condition in vitro. Mechanically, we identified METTL14 knockdown upregulated the level of Sirt1, a well-known protective deacetylase in proteinuric kidney diseases, in podocytes with ADR or AGE treatment. The results of MeRIP-qPCR and dual-luciferase reporter assay indicated METTL14 promoted Sirt1 mRNA m6A modification and degradation in injured podocytes. Our findings suggest METTL14-dependent RNA m6A modification contributes to podocyte injury through posttranscriptional regulation of Sirt1 mRNA, which provide a potential approach for the diagnosis and treatment of podocytopathies.

2020 ◽  
Vol 40 (6) ◽  
Author(s):  
MingJun Shi ◽  
PingPing Tian ◽  
ZhongQiang Liu ◽  
Fan Zhang ◽  
YingYing Zhang ◽  
...  

Abstract Diabetic nephropathy (DN) commonly causes end-stage renal disease (ESRD). Increasing evidence indicates that abnormal miRNA expression is tightly associated with chronic kidney disease (CKD). This work aimed to investigate whether miR-27a can promote the occurrence of renal fibrosis in DN by suppressing the expression of secreted frizzled-related protein 1 (Sfrp1) to activate Wnt/β-catenin signalling. Therefore, we assessed the expression levels of miR-27a, Sfrp1, Wnt signalling components, and extracellular matrix (ECM)-related molecules in vitro and in vivo. Sfrp1 was significantly down-regulated in a high-glucose environment, while miR-27a levels were markedly increased. A luciferase reporter assay confirmed that miR-27a down-regulated Sfrp1 by binding to the 3′ untranslated region directly. Further, NRK-52E cells under high-glucose conditions underwent transfection with miR-27a mimic or the corresponding negative control, miR-27a inhibitor or the corresponding negative control, si-Sfrp1, or combined miR-27a inhibitor and si-Sfrp1. Immunoblotting and immunofluorescence were performed to assess the relative expression levels of Wnt/β-catenin signalling and ECM components. The mRNA levels of Sfrp1, miR-27a, and ECM-related molecules were also detected by quantitative real-time PCR (qPCR). We found that miR-27a inhibitor inactivated Wnt/β-catenin signalling and reduced ECM deposition. Conversely, Wnt/β-catenin signalling was activated, while ECM deposition was increased after transfection with si-Sfrp1. Interestingly, miR-27a inhibitor attenuated the effects of si-Sfrp1. We concluded that miR-27a down-regulated Sfrp1 and activated Wnt/β-catenin signalling to promote renal fibrosis.


2021 ◽  
Vol 3 (4) ◽  
pp. 12-24
Author(s):  
Mabao YUAN ◽  
Hanjiao HANG ◽  
Lubin YAN ◽  
Xuanjie HUANG ◽  
Ziyang SANG ◽  
...  

[Objective] Neuroblastoma is the most common pediatric neuroendocrine tumor. Patients with high-risk neuroblastoma have poor clinical outcomes. Understanding the mechanisms underlying neuroblastoma progression could help identify potential therapeutic targets. This study aimed to explore the roles of itchy E3 ubiquitin-protein ligase (ITCH) in neuroblastoma progression using neuroblastoma cell lines and xenograft models of neuroblastoma. [Methods] ITCH-silencing or overexpressing neuroblastoma cells were established using two different human neuroblastoma cell lines, SK-N-AS and SH-SY5Y. In vitro and in vivo experiments were carried out to determine the effects of ITCH on neuroblastoma cell behaviors. The dual-luciferase reporter assay and co-transfection experiments were applied to determine the interaction of ITCH and miR-145-5p during neuroblastoma progression. [Results] In both cell lines, ITCH overexpression significantly promotes the proliferation, migration, and invasion capacities of neuroblastoma cells, while ITCH silencing with ShITCH suppressed neuroblastoma cell proliferation and induced apoptosis. Moreover, overexpression of ITCH decreased 51% and 54% the protein expressions of large tumor suppressor kinase 1 (LATS1), and inhibited 59% and 66% the phosphorylation of Yes-associated protein (YAP), concomitant with 2.02-fold and 2.56-fold increased expressions of cell proliferation marker Ki67 and 2.51-fold and 2.26-fold elevated levels of anti-apoptosis marker Bcl2 in SK-N-AS and SH-SY5Y cells, respectively. The dual-luciferase reporter assay demonstrated that ITCH interacted with miR-145-5p. Further in vitro and xenograft experiments showed that ITCH negatively affected the tumor-suppressive effect of miR-145-5p. [Conclusion] ITCH promotes neuroblastoma cell proliferation and metastasis by inhibiting LATS1 and promoting YAP nuclear translocation.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Bo Sun ◽  
Xianyu Zheng ◽  
Weilong Ye ◽  
Pengcheng Zhao ◽  
Guowu Ma

Objectives. The aim of this research was to uncover the biological role and mechanisms of LINC01303 in oral squamous cell carcinoma (OSCC). Materials and Methods. Real-time quantitative PCR (qRT-PCR) was used to determine LINC01303 expression in OSCC tissues. Subcellular distribution of LINC01303 was examined by nuclear/cytoplasmic RNA fractionation and FISH experiments. The role of LINC01303 in the growth of TSCCA and SCC-25 was examined by CCK-8 assay, colony formation, transwell invasion assay in vitro, and xenograft tumor experiment in vivo. Dual-luciferase reporter assay was used to verify the interaction between LINC01303 and miR-429. RNA pull‐down assay was used to discover miR-429‐interacted protein, which was further examined by qRT-PCR, western blot, and rescue experiments. Results. LINC01303 expression was higher in OSCC tissues compared with adjacent nontumor tissues. LINC01303 was found to be localized in the cytoplasm of OSCC cells. Knockdown of LINC01303 inhibited OSCC cell proliferation and invasion, whereas increasing the expression of LINC01303 showed the opposite effects. Furthermore, LINC01303 served as a miR-429 “sponge” and positively regulated ZEB1 expression. Moreover, LINC01303 promoted OSCC through miR-429/ZEB1 axis both in vivo and in vitro. Conclusions. LINC01303 plays an oncogenic role in OSCC and is a promising biomarker for OSCC patients.


2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Jingyi Qian ◽  
Bin Wang ◽  
Bicheng Liu

Abstract Background and Aims Vitamin D receptor (VDR) loss, slit diagram (SD) to tight junction (TJ) transition and impaired autophagic flux contribute to podocyte injury in diabetic nephrology. This study aims to examine the effect and mechanism of VDR on autophagic flux and SD-TJ transition in diabetic nephropathy. Method Renal biopsy tissues from DN patients at stage IIa, IIb, III, IV and patients with minimal lesions were used to evaluate the expression of VDR, autophagic flux and SD-TJ transition glomeruli. In vitro, cultured podocytes were treated with serum starvation (SS), autophagic inhibitors (3-methyladenine 3-MA or chloroquine CQ) to determine the degradation pathway of TJ marker ZO-1. Meanwhile, db/db mice and STZ-induced rats were used to explore the therapeutic effect and mechanism of VDR agonist in diabetic nephropathy. Results SD-TJ transition between foot processes could be observed under electron microscopy in DN patients at all stages, whereas foot processes were separated by the filtration slit and appeared to be single cross-strands in the normal glomeruli. There was a trend of increasing expression of autophagic marker p62 and ZO-1 and the expression of p62 is positively correlated with the changes of ZO-1 in the glomeruli of DN patients. In vitro, inhibiting autophagy with 3-MA and CQ resulted in the accumulation of ZO-1 in cultured podocytes. In addition, Co-IP experiments further convinced the interaction between p62 and ZO-1, which was enhanced by the activation of autophagy. Podocytes apoptosis and the activity of caspase 3 and caspase 8 were significantly increased in the presence of 3-MA or CQ, while these effects were rescued by silencing p62. According to VDR gene expression data in GEO database, VDR expression was decreased in diabetic nephropathy patients compared with normal people. Knocking down VDR lowered the expression of atg3 and leaded to the blockage of autophagy, which could be reversed by over-expressing Atg3. Podocytes treated with high glucose resulted in the decrease of VDR and Atg3, impaired autophagic flux and aggravated podocytes injury. However, VDR agonist treatment partially reversed all the changes. In vivo, db/db mice and STZ-induced rats (DN animal models) exhibited SD-TJ transition, massive proteinuria, decreased expression of VDR and podocin and the increased accumulation of p62 and ZO-1, all of which could be partially reversed by VDR agonist. Conclusion VDR loss contributed to the impairment of autophagic flux and SD-TJ transition via down-regulation Atg3 in diabetic nephropathy. Here, we identified a new mechanism and evidence for VDR agonist to treat diabetic nephropathy.


Reproduction ◽  
2020 ◽  
Vol 159 (1) ◽  
pp. 81-89
Author(s):  
Xiaoyan Li ◽  
Jinling Zhu ◽  
Jie Tian ◽  
Dongmei Li ◽  
Xiaodong Han ◽  
...  

Health risk of human exposure to microcystin-leucine arginine (MC-LR) has drawn more and more attention in recent years. In the present study, MC-LR inhibited miR-3473g expression of mouse granulosa cells both in vitro and in vivo. By dual-luciferase reporter assay, we confirmed miR-3473g is able to bind the 3′-UTR of StAR protein (StAR) mRNA and suppress StAR expression. Thus, downregulation of miR-3473g after MC-LR exposure led to StAR overexpression. Excessive StAR probably transported much more cholesterol into the inner membrane of the mitochondria and finally resulted in overproduction of progesterone. Our results revealed that MC-LR exposure was associated with premature luteinization of granulosa cells and may adversely affect women’s fertility.


2020 ◽  
Author(s):  
Fengxun Liu ◽  
Jia Guo ◽  
Yingjin Qiao ◽  
Shaokang Pan ◽  
Jiayu Duan ◽  
...  

Abstract Background : Diabetic nephropathy (DN) is the main cause of chronic kidney disease (CKD) and is one of the most common and serious complications of diabetes mellitus (DM). SIRT1 and TTP are two important protective factors in DN, however, the regulatory relationship between SIRT1 and TTP and the underneath mechanism are interesting but still unclear. Identifying the key factors that regulate SIRT1 or TTP may be of great value to the understanding and treatment of the DN. Methods : in this study, through systematic experimental methods, we found that the expression of miR-138 was significantly up-regulated in DN clinical patients samples, and our experimental results suggested that miR-138 could bind the 3’UTR of SIRT1 and inhibit its expression in both cultured podocytes and db/db mice kidney tissues. Results : furthermore, our in vitro and in vivo date also indicated miR-138 could target SIRT1 and affect TTP through p38 pathway. And down-regulation of miR-138 attenuated podocyte injury and showed some extend of therapeutic effects in DN mice models. Conclusion : our findings reveal that the regulatory axis of miR-138-SIRT1-p38-TTP might play a key role in DN. We believe these findings may be of some value for deepening the understanding of DN and may serve as a reference for future treatment of this disease.


2020 ◽  
Author(s):  
kunwei niu ◽  
Shibin Qu ◽  
Xuan Zhang ◽  
Jimin Dai ◽  
Jianlin Wang ◽  
...  

Abstract Background: To investigate the underlying mechanisms of lncRNA URHC in HCC. Methods: RT-qPCR, FISH staining, EdU, colony formation, and tumor xenografts experiments were used to identify localized and biological effects of URHC on HCC cells in vitro and in vivo. The Bioinformatics analysis, Dual- luciferase reporter assay, and rescue experiments revealed the potential mechanism of URHC. Results: We found that URHC was mainly localized in the cytoplasm. URHC silencing may inhibit the HCC cells proliferation. And URHC positively regulated the level of DNAJB9 by sponging miR-5007-3p. Conclusion: Together, our study elucidated the role of URHC as a miRNA sponge in HCC, and shed new light on lncRNA-directed diagnostics and therapeutics in HCC.


2013 ◽  
Vol 305 (5) ◽  
pp. F691-F700 ◽  
Author(s):  
Khaled Khazim ◽  
Yves Gorin ◽  
Rita Cassia Cavaglieri ◽  
Hanna E. Abboud ◽  
Paolo Fanti

Podocyte injury, a major contributor to the pathogenesis of diabetic nephropathy, is caused at least in part by the excessive generation of reactive oxygen species (ROS). Overproduction of superoxide by the NADPH oxidase isoform Nox4 plays an important role in podocyte injury. The plant extract silymarin is attributed antioxidant and antiproteinuric effects in humans and in animal models of diabetic nephropathy. We investigated the effect of silybin, the active constituent of silymarin, in cultures of mouse podocytes and in the OVE26 mouse, a model of type 1 diabetes mellitus and diabetic nephropathy. Exposure of podocytes to high glucose (HG) increased 60% the intracellular superoxide production, 90% the NADPH oxidase activity, 100% the Nox4 expression, and 150% the number of apoptotic cells, effects that were completely blocked by 10 μM silybin. These in vitro observations were confirmed by similar in vivo findings. The kidney cortex of vehicle-treated control OVE26 mice displayed greater Nox4 expression and twice as much superoxide production than cortex of silybin-treated mice. The glomeruli of control OVE26 mice displayed 35% podocyte drop out that was not present in the silybin-treated mice. Finally, the OVE26 mice experienced 54% more pronounced albuminuria than the silybin-treated animals. In conclusion, this study demonstrates a protective effect of silybin against HG-induced podocyte injury and extends this finding to an animal model of diabetic nephropathy.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Yingchun Zhu ◽  
Jiang Xu ◽  
Wenxing Liang ◽  
Ji Li ◽  
Linhong Feng ◽  
...  

Recently, microRNAs have been recognized as crucial regulators of diabetic nephropathy (DN) development. Epithelial-to-mesenchymal transition (EMT) can play a significant role in tubulointerstitial fibrosis, and it is a hallmark of diabetic nephropathy progression. Nevertheless, the function of miR-98-5p in the modulation of EMT and renal fibrosis during DN remains barely investigated. Hence, identifying the mechanisms of miR-98-5p in regulating EMT and fibrosis is of huge significance. In our present research, decreased miR-98-5p was demonstrated in db/db mice and mice mesangial cells treated with the high dose of glucose. Meanwhile, activated EMT and increased fibrosis was accompanied with the decrease of miR-98-5p in vitro and in vivo. Additionally, to further find out the roles of miR-98-5p in DN development, overexpression of miR-98-5p was applied. Firstly, in vivo investigation exhibited that elevation of miR-98-5p restrained proteinuria, serum creatinine, BUN, the EMT process, and fibrosis. Furthermore, high glucose was able to promote mice mesangial cell proliferation, EMT process, and induced renal fibrosis, which could be prevented by overexpression of miR-98-5p. Moreover, high mobility group A (HMGA2) can exhibit an important role in diverse biological processes. Here, HMGA2 was investigated as a target of miR-98-5p currently. Luciferase reporter assay was conducted and the correlation of miR-98-5p and HMGA2 was validated. Moreover, it was displayed that HMGA2 was remarkably elevated in db/db mice and mice mesangial cells. Furthermore, miR-98-5p strongly depressed HMGA2 protein and mRNA levels in mice mesangial cells. Overall, these revealed miR-98-5p could suppress the EMT process and renal fibrosis through targeting HMGA2 in DN.


2021 ◽  
Vol 12 ◽  
Author(s):  
Wen Li ◽  
Jing Sun ◽  
Xiaoxi Zhou ◽  
Yue Lu ◽  
Wenpeng Cui ◽  
...  

Pyroptosis is a recently identified type of lytic programmed cell death, in which pores form in the plasma membrane, and cells swell, rupture, and then release their contents, including inflammatory cytokines. Molecular studies indicated that pyroptosis may occur via a gasdermin D (GSDMD) and caspase-1 (Casp1) -dependent classical pathway, a GSDMD and Casp11/4/5-dependent non-classical pathway, or a gasdermin E (GSDME) and Casp3-dependent pathway. Studies of animal models and humans indicated that pyroptosis can exacerbate several complications of diabetes, including diabetic nephropathy (DN), a serious microvascular complication of diabetes. Many studies investigated the mechanism mediating the renoprotective effect of GSDMD regulation in the kidneys of patients and animal models with diabetes. As a newly discovered regulatory mechanism, GSDME and Casp3-dependent pyroptotic pathway in the progression of DN has also attracted people’s attention. Z-DEVD-FMK, an inhibitor of Casp3, ameliorates albuminuria, improves renal function, and reduces tubulointerstitial fibrosis in diabetic mice, and these effects are associated with the inhibition of GSDME. Studies of HK-2 cells indicated that the molecular and histological features of secondary necrosis were present following glucose stimulation due to GSDME cleavage, such as cell swelling, and release of cellular contents. Therefore, therapies targeting Casp3/GSDME-dependent pyroptosis have potential for treatment of DN. A novel nephroprotective strategy that employs GSDME-derived peptides which are directed against Casp3-induced cell death may be a key breakthrough. This mini-review describes the discovery and history of research in this pyroptosis pathway and reviews the function of proteins in the gasdermin family, with a focus on the role of GSDME-mediated pyroptosis in DN. Many studies have investigated the impact of GSDME-mediated pyroptosis in kidney diseases, and these studies used multiple interventions, in vitro models, and in vivo models. We expect that further research on the function of GDSME in DN may provide valuable insights that may help to improve treatments for this disease.


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