Objective To explore the functional impact of A-to-I editing in the seed region of miR-411 during post-myocardial infarction (MI) fibrosis and elucidate its therapeutic potential. Methods Integrating GEO database with myocardial RNA-seq data from MI mouse models, we identified dynamic A-to-I RNA editing in small noncoding RNAs across MI progression (1 day to 8 weeks post-MI). Four miRNAs exhibited differential editing rates between MI and controls, with miR-411 showing progressive editing enhancement at seed region position 4 (P＜0.01). This editing event was validated in both murine MI models and human heart failure specimens. Results The A-to-I editing ratio change of the 4th nucleotide in the seed region of miR-411 mainly occurs in cardiac fibroblasts rather than cardiomyocytes, and the editing at this site depends on ADAR2 rather than ADAR1. Edited miR-411 (ED-miR-411) diverged from wild-type miR-411 (WT-miR-411) in suppressing collagen-related pathways (extracellular matrix [ECM]-receptor interaction, collagen-containing ECM, ECM organization; P＜0.01) in cardiac fibroblasts. Mechanistically, dual-luciferase assays confirmed ED-miR-411 directly targeted the 3′UTR and suppressed expression of type Ⅱ transforming growth factor (TGF)-beta receptor (TGFBR2) and CD44, which were key drivers of TGF-β-mediated fibroblast activation. ED-miR-411 overexpression blunted TGF-β-induced collagen synthesis and myofibroblast proliferation (P＜0.05). In vivo, intramyocardial delivery of ED-miR-411 mimics at 1 week post-MI reduced fibrosis by 40% and improved ejection fraction by 15% (P＜0.01 vs controls), whereas WT-miR-411 showed no therapeutic effect. Conclusions A-to-I editing of miR-411 emerges as an endogenous anti-fibrotic mechanism by repressing TGFBR2 and CD44, thereby disrupting TGF-β signaling and ECM dysregulation. Our findings highlight ED-miR-411 as a novel RNA-based therapeutic candidate to mitigate post-infarction cardiac remodeling.

Objective To explore the difference of transfer RNA-derived small RNA(tsRNA)expression profile before and after acute myocardial infarction(AMI)and the diagnostic value of tsRNA for AMI.Methods Age-and weight-matched male C57 mice(8-10 weeks)were randomly divided into MI group and Sham group,with 4 in each group.AMI model was surgically induced in mice in MI group.After 24 h of modeling,RNA was extracted from left ventricular myocardial tissue.After removing modifications,total RNA of each sample was sequentially ligated to 3'and 5'small RNA adapters.Subsequently,reverse transcription PCR was performed.cDNA was then synthesized and amplified.The amplified products corresponding to the size of 15-40 nt RNA were screened to construct a library for sequencing.The sequencing results were compared with the mature tRNA and tRNA precursor sequences in GtRNAdb database.Differentially expressed tsRNA profiles before and after AMI were obtained.The alterations of the cleaved patterns of tRNA corresponding to the same codon before and after AMI were analyzed.According to the profile of differentially expressed tsRNA before and after AMI,tsRNA only abundantly expressed in MI group were selected and verified in myocardial tissue and plasma of mice to explore the potential of these tsRNAs as diagnostic markers of AMI.Results tsRNA profile showed good repeatability within the same group and great distinctiveness between the different groups.After AMI occurred,the cleaved patterns of a variety of tRNAs changed,including tRNA Asn-GTT,Glu-TTC,Gly-ACC,Gly-GCC,His-GTG,Ile-AAT,Ile-GAT,Pro-TGG,Ser-AGA,and Trp-CCA.Compared with the Sham group,268 tsRNAs significantly up-regulated and 1 228 tsRNAs down-regulated in MI group,and 64 tsRNAs were uniquely expressed in MI group.tRF-Gly-CCC-2-31,tiRNA-Val-CAC-1-32,tiRNA-Val-AAC-2-32,tiRNA-Glu-TTC-2-32,and tiRNA-Lys-TTT-1-34 were specifically expressed in cardiac tissue on the 1st day post AMI.Among them,tiRNA-Val-AAC-2-32 and tiRNA-Lys-TTT-1-34 showed specifically abundant levels in plasma from MI group and dynamically changed with AMI duration.Conclusions The expression profile of tsRNA is significantly different before and after AMI.tiRNA-Val-AAC-2-32 and tiRNA-Lys-TTT-1-34 are uniquely highly expressed in myocardial tissue and plasma from AMI mice,and might have the potential as diagnostic markers of AMI.

Objective To determine the prevalence and treatment of chronic obstructive pulmonary diseases (COPD) among citizens in Ningbo. Methods A multi-stage stratified random sampling was applied to select 8 neighborhoods and 3 villages out of 7 districts in Ningbo, people who were older than or equal to 40 years were enrolled as subjects. Information on the prevalence rate and treatment conditions of COPD was collected through respiratory symptoms and treatment questionnaire and lung function screening. Results A total of 5865 people were screened, 5674 of them met inclusion criteria and completed questionnaire and lung function test. Among whom, 3044 people were men (53.6%, the average age is 55.7±11.4), 2630 women (46.4%, the average age was 55.3 ± 10.7);473 of them were diagnosed with COPD, the overall prevalence rate was 8.3%, including 354 cases who had never been diagnosed as COPD, accounted for 74.8% of the total cases diagnosed with COPD, mainly in stage ⅠandⅡof the disease. There were statistically significant differences between diagnosed and undiagnosed patients in the overall COPD group and among different gender groups ( stagesⅠandⅡ) and (stagesⅢandⅣ). Among the 473 COPD cases, 119 (diagnostic yield 25.2%) of whom had been diagnosed with bronchitis, only 48 (41.2%of the diagnosed) received drug treatment, only 13 patients were treated regularly with medication. Conclusion The overall prevalence rate of COPD among those over 40 years of age in Ningbo was quite high and mainly had stagesⅠandⅡof the disease. The number of the diagnostic yield and those who received regular treatment are quite low. The current situation of diagnosis and treatment are far from satisfaction, management of COPD should be strengthened to reduce the burden for family and society.