Dynamic Patterns of N6-Methyladenosine Profiles of Messenger RNA Correlated with the Cardiomyocyte Regenerability during the Early Heart Development in Mice.

N6-Methyladenosine (m6A) plays important roles in regulating mRNA processing. Despite rapid progress in this field, little is known about the role and mechanism of m6A modification in myocardial development and cardiomyocyte regeneration. Existing studies have shown that the heart tissues of newborn mice have the capability of proliferation and regeneration, but its mechanism, particularly its relation to m6A methylation, remains unknown. Methods. To systematically profile the mRNA m6A modification pattern in the heart tissues of mice at different developmental stages, we jointly performed methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA sequencing (RNA-seq) of heart tissues of mice, respectively, aged 1 day old, 7 days old, and 28 days old. Results. We identified the linkages and association between differentially expressed mRNA transcripts and hyper or hypomethylated m6A peaks in C57BL/6J mice at different heart developmental stages. Results showed that the amount of m6A peaks and the level of m6A modification were the lowest in the heart of mice at 1 day old. By contrast, heart tissues from 7-day-old mice tended to possess the most m6A peaks and the highest global m6A level. However, the m6A characteristics of myocardial tissue changed little after 7 days old as compared to that of 1 day old. Specifically, we found 1269 downmethylated genes of 1434 methylated genes in 7-day-old mouse heart tissues as compared to those in 1-day-old mice. Hypermethylation of some specific genes may correlate with the heart's strong proliferative and regenerative capability at the first day after birth. In terms of m6A density, the tendency shifted from coding sequences (CDS) to 3'-untranslated regions (3'UTR) and stop codon with the progression of heart development. In addition, some genes demonstrated remarkable changes both in methylation and expression, like kiss1, plekha6, and megf6, which may play important roles in proliferation. Furthermore, signaling pathways highly related to proliferation such as "Wnt signaling pathway," "ECM-receptor interaction," and "cardiac chamber formation" were significantly enriched in 1-day-old methylated genes. Conclusions. Our results reveal a pattern that different m6A modifications are distributed in C57BL/6J heart tissue at different developmental stages, which provides new insights into a novel function of m6A methylation of mRNA in myocardial development and regeneration.

MicroRNA files in the prevention of intestinal ischemia/reperfusion injury by hydrogen rich saline.

BACKGROUND: Hydrogen-rich saline (HRS) has been proven effective against ischemia/reperfusion (I/R) injury. However, knowledge on the underlying signaling events remain poor. Having recent highlight of microRNAs (miRNAs) in mediating intestinal I/R injury, we hypothesized that HRS may protect intestine against I/R injury by regulating miRNAs. METHOD: Mice were given intraperitoneal injection of saline or HRS once daily for five consecutive days before undergoing intestinal I/R that was induced by 60-min ischemia followed by 180-min reperfusion of superior mesenteric artery. The intestine was collected for histopathological assay, miRNA microarray profiling, Real-Time PCR, and Western blotting. Next, miR-199a-3p mimics or inhibitors were transfected into IEC-6 cells to explore the relationship between HRS treatment and miR-199a-3p. RESULTS: I/R-induced mucosal injury and epithelial cells apoptosis were attenuated by HRS pretreatment. A total of 64 intestinal I/R-responsive miRNAs were altered significantly by HRS pretreatment, in which we validated four novel miRNAs with top significance by Real-Time PCR, namely miR-199a-3p, miR-296-5p, miR-5126, and miR-6538. Particularly, miR-199a-3p was drastically increased by I/R but reduced by HRS. Computational analysis predicts insulin-like growth factor (IGF)-1, mammalian target of rapamycin (mTOR), and phosphoinositide-3-kinase (PI3K) regulatory subunit 1 as targets of miR-199a-3p, suggesting involvement of the pro-survival pathway, IGF- 1/PI3K/Akt/mTOR. In in vitro experiment, HRS treatment reduced miR-199a-3p level, increase IGF-1, PI3K and mTOR mRNA expression, restore IEC-6 cells viability, and this protective effects were reversed under miR-199a-3p mimics treatment. CONCLUSION: Collectively, miR-199a-3p may serve a key role in the anti-apoptotic mechanism of HRS that contributes to its protection of the intestine against I/R injury.

[Laparoscopic cholecystectomy with remote zeus surgical robotic system: report of 16 cases].

OBJECTIVE: To explore the methodology and operative essentials of laparoscopic cholecystectomy with remote Zeus surgical robotic system. METHODS: Based on strict training and successful experiment in animal model of swine, laparoscopic cholecystectomy using Zeus robotic system was performed on 16 patients with biliary diseases, including choledocholithiasis, cholelithiasis, polyposis of gallbladder, and chronic cholecystitis, 10 males and 16 females, aged 33 (14 approximately 27), 26 April to 31 August 2004. The general data, preoperative preparation time, operation time, amount of bleeding, complications, and hospitalization time were analyzed. RESULTS: All operations were performed without event. Along with the accumulation of experience the preoperative preparation time was shortened from 90 min to 30 min with an average of 41.7 min, and the operation time from 120 min to 30 min with an average of 64.4 min. The average amount of bleeding was 27.7 ml, and the average postoperative hospitalization time was 2.4 d. A telephone follow-up 30 days after operation showed no abnormality. CONCLUSION: Laparoscopic cholecystectomy with Zeus surgical robotic system is feasible and reliable with the advantages of clearer images in the field of operation, more precise handling, and remote surgery or education.