Chromodomain Y-like (CDYL) inhibition ameliorates acute kidney injury in mice by regulating tubular pyroptosis.

Acute kidney injury (AKI) is a common disease, but lacking effective drug treatments. Chromodomain Y-like (CDYL) is a kind of chromodomain protein that has been implicated in transcription regulation of autosomal dominant polycystic kidney disease. Benzo[d]oxazol-2(3H)-one derivative (compound D03) is the first potent and selective small-molecule inhibitor of CDYL (KD = 0.5 µM). In this study, we investigated the expression of CDYL in three different models of cisplatin (Cis)-, lipopolysaccharide (LPS)- and ischemia/reperfusion injury (IRI)-induced AKI mice. By conducting RNA sequencing and difference analysis of kidney samples, we found that tubular CDYL was abnormally and highly expressed in injured kidneys of AKI patients and mice. Overexpression of CDYL in cisplatin-induced AKI mice aggravated tubular injury and pyroptosis via regulating fatty acid binding protein 4 (FABP4)-mediated reactive oxygen species production. Treatment of cisplatin-induced AKI mice with compound D03 (2.5 mg·kg-1·d-1, i.p.) effectively attenuated the kidney dysfunction, pathological damages and tubular pyroptosis without side effects on liver or kidney function and other tissue injuries. Collectively, this study has, for the first time, explored a novel aspect of CDYL for tubular epithelial cell pyroptosis in kidney injury, and confirmed that inhibition of CDYL might be a promising therapeutic strategy against AKI.

The SUMOylated METTL8 Induces R-loop and Tumorigenesis via m3C.

R-loops, three-stranded DNA-DNA:RNA hybrid structures, are best known for their deleterious effects on genome stability. The regulatory factors of this fundamental genetic structure remain unclear. Here, we reveal an epigenetic factor that controls R-loop stability. METTL8, a member of the methyltransferase-like protein family that methylates 3-methylcytidine (m3C), is a key factor in the R-loop regulating methyltransferase complex. Biochemical studies show that METTL8 forms a large SUMOylated nuclear RNA-binding protein complex (∼0.8 mega daltons) that contains well-reported R-loop related factors. Genetic ablation of METTL8 results in an overall reduction of R-loops in cells. Interaction assays indicated METTL8 binds to RNAs and is responsible for R-loop stability on selected gene regions. Our results demonstrate that the SUMOylated METTL8 promotes tumorigenesis by affecting genetic organization primarily in, or in close proximity to, the nucleolus and impacts the formation of regulatory R-loops through its methyltransferase activity on m3C.

[Effects of cardiotrophin-1 on differentiation of cardiomyocyte-like cells induced from rat bone marrow mesenchymal stem cells].

OBJECTIVE: To investigate the effects of cardiotrophin-1 (CT-1) on differentiation of induced rat bone marrow mesenchymal stem cells (BMMSCs) in vitro with 5-azacytidine (5-aza) for the purpose of elucidation of the cellular biological mechanisms. METHODS: BMMSCs isolated from femur of rats were divided into four groups: untreated group as control (group A); 0.1 nmol/L CT-1 added to medium (Group B); induced with 10 micromol/L 5-aza only (Group C); induced with 10 micromol/L 5-aza combined with 0.1 nmol/L CT-1 added to medium (Group D). After 4 weeks of induced culturing, the differentiation of induced myocyte like cells were estimated, levels of cardiac troponin-T (cTnT) by immunohistochemical staining and ultrastructure of induce-cultured BMMSCs were determined and mRNA expression of alpha-actin, beta-myosin heavy chain (beta-MHC), Nkx2.5, GATA4 were analyzed by real time polymerase chain reaction (RT-PCR). RESULTS: After 4 weeks of induced culturing, morphological characteristics of myocyte like cells with the expression of cTnT were observed in group C and D cells. Higher level expression of GATA4, Nkx2.5, alpha- actin and beta-MHC mRNA in group D was observed by comparing with those of group C and the differentiated BMMSCs with formations of myofilaments distinctly were also existed in 5-aza combined with CT-1 treatment group. CONCLUSION: This study suggests that induced culturing of BMMSCs in the presence of 5-aza combined with CT-1 can enhance cardiomyocytic characteristics. CT-1 upregulates the expression of GATA4, Nkx2.5, alpha-actin and beta-MHC mRNA, and rapidly promotes the differentiation and maturation of cardiomyocyte-like cells differentiated from BMMSCs induced with 5-aza.

[Correlation between desmin gene, platelet-activating factor acetylhydrolase gene and dilated cardiomyopathy].

OBJECTIVE: To test the Missense mutation of Desmin gene (Ile451Met), the frequency of missense mutation (G994-->T) of Platelet-Activating Factor Acetylhydrolase (PAF-AH) gene, and the correlation between these mutations and dilated cardiomyopathy (DCM) in the Chinese population with DCM. METHODS: A case control study was conducted with 89 DCM patients and 110 healthy people (control group) participating in the study. The exon 8 of Desmin gene and exon 9 of PAF-AH gene were identified by polymerase chain reaction, restriction enzyme digestion, polyacrylamide gel electrophoresis and DNA sequencing for described mutation site of Desmin (Ile451Met) and PAF-AH (Val279Phe). RESULTS: No mutation (Ile451Met) in Desmin gene was found in either the DCM patients or the healthy people. There was no significant difference in the frequency of PAF-AH gene mutation (Val279Phe) between the patient and control groups (P>0.05). CONCLUSION: Neither the mutation of Ile451Met in gene encoding for Desmin exon 8 nor the mutation frequency of PAF-AH gene (G994-->T) has correlation with the DCM.

[Association between phospholamban gene mutation and dilated cardiomyopathy in the Chengdu area].

OBJECTIVE: To find out whether phospholamban (PLN) is the virulence gene of dilated cardiomyopathy (DCM) in the Chinese of Chengdu. METHODS: DNA was isolated from 89 hospitalized unrelated patients with DCM and 110 healthy Chinese Hans as controls. The PLN mutations was screened by polymerase chain reaction (PCR)-single strand conformation polymorphisms (SSCP) and nucleotide sequence analysis. RESULTS: In polyacrylamide gel lectrophoresis, no abnormal conformer was found in the two groups. In DNA sequence, no C --> T missense mutation at nucleotide 25 was identified in the DCM patients and the controls. Meanwhile, T --> G missense mutation at nucleotide 116 was not found in the affected individuals and in the controls. CONCLUSION: No PLN gene mutation was found in patients with DCM in Chengdu. This result indicated that PLN gene mutation may not be a common cause for DCM in the Chinese population in Chengdu.