Genetic and pharmacological inhibition of METTL3 alleviates renal fibrosis by reducing EVL m6A modification through an IGF2BP2-dependent mechanism.

BACKGROUND: N6 -methyladenosine (m6A) is of great importance in renal physiology and disease progression, but its function and mechanism in renal fibrosis remain to be comprehensively and extensively explored. Hence, this study will explore the function and potential mechanism of critical regulator-mediated m6A modification during renal fibrosis and thereby explore promising anti-renal fibrosis agents. METHODS: Renal tissues from humans and mice as well as HK-2 cells were used as research subjects. The profiles of m6A modification and regulators in renal fibrosis were analysed at the protein and RNA levels using Western blotting, quantitative real-time polymerase chain reaction and other methods. Methylation RNA immunoprecipitation sequencing and RNA sequencing coupled with methyltransferase-like 3 (METTL3) conditional knockout were used to explore the function of METTL3 and potential targets. Gene silencing and overexpression combined with RNA immunoprecipitation were performed to investigate the underlying mechanism by which METTL3 regulates the Ena/VASP-like (EVL) m6A modification that promotes renal fibrosis. Molecular docking and virtual screening with in vitro and in vivo experiments were applied to screen promising traditional Chinese medicine (TCM) monomers and explore their mechanism of regulating the METTL3/EVL m6A axis and anti-renal fibrosis. RESULTS: METTL3 and m6A modifications were hyperactivated in both the tubular region of fibrotic kidneys and HK-2 cells. Upregulated METTL3 enhanced the m6A modification of EVL mRNA to improve its stability and expression in an insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2)-dependent manner. Highly expressed EVL binding to Smad7 abrogated the Smad7-induced suppression of transforming growth factor-ß (TGF-ß1)/Smad3 signal transduction, which conversely facilitated renal fibrosis progression. Molecular docking and virtual screening based on the structure of METTL3 identified a TCM monomer named isoforsythiaside, which inhibited METTL3 activity together with the METTL3/EVL m6A axis to exert anti-renal fibrosis effects. CONCLUSIONS: Collectively, the overactivated METTL3/EVL m6A axis is a potential target for renal fibrosis therapy, and the pharmacological inhibition of METTL3 activity by isoforsythiaside suggests that it is a promising anti-renal fibrosis agent.

RNA N6 -methyladenosine modifications and potential targeted therapeutic strategies in kidney disease.

Epigenetic modifications have received increasing attention and have been shown to be extensively involved in kidney development and disease progression. Among them, the most common RNA modification, N6 -methyladenosine (m6 A), has been shown to dynamically and reversibly exert its functions in multiple ways, including splicing, export, decay and translation initiation efficiency to regulate mRNA fate. Moreover, m6 A has also been reported to exert biological effects by destabilizing base pairing to modulate various functions of RNAs. Most importantly, an increasing number of kidney diseases, such as renal cell carcinoma, acute kidney injury and chronic kidney disease, have been found to be associated with aberrant m6 A patterns. In this review, we comprehensively review the critical roles of m6 A in kidney diseases and discuss the possibilities and relevance of m6 A-targeted epigenetic therapy, with an integrated comprehensive description of the detailed alterations in specific loci that contribute to cellular processes that are associated with kidney diseases.

[Causes of and risk factors for failure in catheter removal after transurethral resection of the prostate].

OBJECTIVE: To find the causes of the failure in the first catheter removal (CR) after transurethral resection of the prostate (TURP) and the related risk factors. METHODS: We collected the clinical data on 285 BPH patients treated by TURP from June 2015 to May 2018. We divided the cases into a successful CR (SCR) and a failed CR (FCR) group and investigated the risk factors for the first CR after TURP by multivariate logistic regression analysis. RESULTS: CR was successfully performed in 246 and failed in 39 of the 285 cases. In the FCR group, post-CR urinary retention occurred in 15 cases immediately after, severe urinary tract irritation in 13, massive gross hematuria in 7 and urinary incontinence in 4 within 1 month. Multivariate logistic regression analysis showed that the independent risk factors for CR failure included IPSS (OR = 5.106, P = 0.013), preoperative urinary tract infection (OR = 3.835, P = 0.041), prostate volume (OR = 4.160, P = 0.011) and catheter compression time (OR = 4.051, P = 0.017). CONCLUSIONS: The common causes of the failure in catheter removal after TURP included early postoperative urinary retention, urinary infection, secondary hematuria and urinary incontinence.