Circulating miR-133a and miR-423-5p fail as biomarkers for left ventricular remodeling after myocardial infarction

Background

Recent studies have suggested that the microRNAs miR-133a and miR-423-5p may serve as useful biomarkers in patients with left ventricular (LV) heart failure or with LV remodeling after myocardial infarction (MI). These results were however obtained in small series of patients and control subjects were used as reference groups. Whether these microRNAs may be indicators of the degree of LV remodeling after MI is unknown.

Methods

246 patients with a first anterior Q-wave MI were included. Serial echocardiographic studies were performed at hospital discharge, 3 months, and 1 year after MI and analyzed at a core laboratory. We investigated the temporal profile (baseline, 1, 3 and 12 months) of circulating miR-133a and miR-423-5p and their relations with cardiac biomarkers (B-type natriuretic peptide, C-reactive protein, and cardiac troponin I) and LV remodeling during the 1 year follow-up.

Results

There were time-dependent changes in the levels of circulating miR-133a and miR-423-5p with significant increase of miR-133a at 12 months compared to 3 months and significant increase of miR-423-5p at 1, 3, and 12 months compared to baseline. However, miR-133a and miR-423-5p were not associated with indices of LV function and LV remodeling serially assessed during a 1 year period after an acute anterior MI, nor with B-type natriuretic peptide.

Conclusions

Circulating levels of miR-133a and miR-423-5p are not useful biomarkers of LV remodeling after MI.     

微小RNA在急性肺损伤中基因研究进展

微小RNA﹙microRNAs,miRNAs﹚是由21～23个核苷酸组成的非编码RNA,作为一种基因表达的负性调节因子,可以调控其靶mRNA稳定性及翻译效率。急性肺损伤﹙acute lung injury,ALI﹚/急性呼吸窘迫综合征（acute respiratory distress syndrome,ARDS）指创伤、感染、休克等疾病导致的进行性缺氧性呼吸衰竭,主要的病理生理改变是弥漫性肺毛细血管内皮-肺泡上皮屏障功能的破坏及炎症损害,ALI/ARDS是临床常见危重症,病死率高,发病机制非常复杂,且不完全明确,近年来大量关于疾病与miRNA关系的文献报导,miRNA 是众多基因的关键调节者,在细胞凋亡过程中起关键作用,从而影响疾病的发生及展。本文对近年来国内外有关miRNA在急性肺损伤中的作用作简要阐述。     

小鼠microRNA-21慢病毒抑制载体的构建及鉴定

目的构建microRNA-21(miR-21)慢病毒抑制载体,为研究miR-21在小鼠体内的功能及作用机制打下基础。方法利用miR-21前体并将其克隆入LV3pGLV-H1-GFP质粒中,经酶切及测序鉴定,利用脂质体将鉴定的阳性重组LV3pGLV-H1-GFP-miR-21抑制载体、PG-P1-VSVG和pCMV-dR3个质粒转染到HEK-293T细胞,将所得病毒感染293T细胞,检测病毒滴度,并将制备的病毒颗粒感染乳鼠心肌细胞和尾静脉注射小鼠,检测miR-21在小鼠体内的表达。结果酶切及测序结果证明成功构建了LV3pGLV-H1-GFP-miR-21重组质粒,并成功包装成慢病毒,病毒滴度为2.4×109TU/ml,重组病毒成功感染心肌细胞,同时在Balb/c小鼠心脏有表达。结论成功构建miR-21慢病毒抑制载体,获得高效表达miR-21的慢病毒颗粒,为miR-21的进一步研究奠定了基础。     

微小RNA在宫颈癌中的研究进展

早期诊断、早期治疗是降低肿瘤病死率的有效途径。微小RNA(miRNA)作为一种小分子的非编码调控的单链RNA,由于其与肿瘤发生、发展密切相关,被认为有可能成为一类新的肿瘤标志物和抗肿瘤治疗靶点,从而为肿瘤的早期诊断及治疗带来新的希望。目前,miRNA在宫颈癌的研究尚处于初级阶段,有研究发现miRNA通过与人乳头瘤病毒(HPV)之间的相互作用可以影响宫颈癌的发生、发展。该文对近年来miRNA在宫颈癌中的最新研究进展,特别是在宫颈癌的发生、发展中的作用及与HPV的相互关系予以综述。     

微小RNA与肿瘤研究进展

微小核糖核酸(miRNA)是一类在生物体中广泛表达的、非编码调节性小分子RNA。成熟的miRNA与RNA诱导沉默复合体结合后,通过与靶mRNA的特定序列互补或不完全互补结合,进而发挥阻遏翻译或引导酶切的功能。miRNA具有多种生物学功能,如调节细胞发育、分化、增殖、凋亡、免疫与应激反应等,并且具有肿瘤抑制因子及癌基因的作用,可能是诊断、治疗肿瘤的一种潜在手段。     

微小RNA与子宫内膜异位症

子宫内膜异位症(简称内异症)是生育年龄妇女的常见病,病因机制复杂。其病变广泛,极具侵袭性和复发性,呈现恶性临床行为。微小RNA(miRNA)在细胞增殖、分化和凋亡等多种细胞生长和发育过程中起重要的调控作用。其参与调控内异症黏附和侵袭、细胞生长和增殖及血管形成,在内异症恶性转化中具有重要作用。随着反义技术和基因治疗领域技术的发展,miRNA有望成为内异症诊断和治疗的新的切入点。     

微小RNA对血管新生的调控机制研究进展

微小RNA（miRNA）是一类重要调控因子,在转录后水平调控细胞增殖分化、凋亡、分裂以及器官的发育.据估计,miRNA调节着人类细胞大约1/3的蛋白质表达,进而参与几乎所有生命体的生理及病理过程.大量研究证实,内皮特异miRNA参与调控血管新生过程各个环节,在血管新生的调控方面发挥着非常关键的作用.miR-126、miR-210、miR-424、Let-7等具有促进血管新生作用;miR-221/miR-222、miR-34a、miR-217等则具有抑制血管新生作用.并且miRNA合成过程中两个关键性酶Dicer和aDrosha也在血管新生中占居重要地位.因此,miRNA可能成为一种新的心血管疾病诊断和靶向治疗的生物学标志物.     

Expression of 19 microRNAs in glioblastoma and comparison with other brain neoplasia of grades I–III

Several biomarkers have been proposed as useful parameters to better specify the prognosis or to delineate new target therapy strategies for glioblastoma patients. MicroRNAs could represent putative target molecules, considering their role in tumorigenesis, cancer progression and their specific tissue expression. Although several studies have tried to identify microRNA signature for glioblastoma, a microRNA profile is still far from being well‐defined.In this work the expression of 19 microRNAs (miR‐7, miR‐9, miR‐9∗, miR‐10a, miR‐10b, miR‐17, miR‐20a, miR‐21, miR‐26a, miR‐27a, miR‐31, miR‐34a, miR‐101, miR‐137, miR‐182, miR‐221, miR‐222, miR‐330, miR‐519d) was evaluated in sixty formalin‐fixed and paraffin‐embedded glioblastoma samples using a locked nucleic acid real‐time PCR. Moreover, a comparison of miRNA expressions was performed between primary brain neoplasias of different grades (grades IV–I).The analysis of 14 validated miRNA expression in the 60 glioblastomas, using three different non‐neoplastic references as controls, revealed a putative miRNA signature: mir‐10b and miR‐21 were up‐regulated, while miR‐7, miR‐31, miR‐101, miR‐137, miR‐222 and miR‐330 were down‐regulated in glioblastomas. Comparing miRNA expression between glioblastoma group and gliomas of grades I–III, 3 miRNAs (miR‐10b, mir‐34a and miR‐101) showed different regulation statuses between high‐grade and low‐grade tumors. miR‐10b was up‐regulated in high grade and significantly down‐regulated in low‐grade gliomas, suggesting that could be a candidate for a GBM target therapy.This study provides further data for the identification of a miRNA profile for glioblastoma and suggests that different‐grade neoplasia could be characterized by different expression of specific miRNAs.     

MicroRNA-145 targets MUC13 and suppresses growth and invasion of pancreatic cancer

Pancreatic cancer has a poor prognosis due to late diagnosis and ineffective therapeutic multimodality. MUC13, a transmembrane mucin is highly involved in pancreatic cancer progression. Thus, understanding its regulatory molecular mechanisms may offer new avenue of therapy for prevention/treatment of pancreatic cancer. Herein, we report a novel microRNA (miR-145)-mediated mechanism regulating aberrant MUC13 expression in pancreatic cancer. We report that miR-145 expression inversely correlates with MUC13 expression in pancreatic cancer cells and human tumor tissues. miR-145 is predominantly present in normal pancreatic tissues and early Pancreatic Ductal Adenocarcinoma (PDAC) precursor lesions (PanIN I) and is progressively suppressed over the course of development from PanIN II/III to late stage poorly differentiated PDAC. We demonstrate that miR-145 targets 3′ untranslated region of MUC13 and thus downregulates MUC13 protein expression in cells. Interestingly, transfection of miR-145 inhibits cell proliferation, invasion and enhances gemcitabine sensitivity. It causes reduction of HER2, P-AKT, PAK1 and an increase in p53. Similar results were found when MUC13 was specifically inhibited by shRNA directed at MUC13. Additionally, intratumoral injections of miR-145 in xenograft mice inhibited tumor growth via suppression of MUC13 and its downstream target, HER2. These results suggest miR-145 as a novel regulator of MUC13 in pancreatic cancer.     

MiR-153-3p调控异丙肾上腺素诱导的心肌肥大机制研究

目的 本研究旨在利用异丙肾上腺素(isoproterenol,ISO)诱导心肌细胞肥大,研究miR-153-3p调控心肌肥大的作用机制。方法 体外分离培养大鼠乳鼠心肌细胞,通过ISO不同时间（0、8、12、18、24、48 h）梯度培养检测细胞肥大情况以及miR-153-3p的表达情况;转染miR-153-3p的拮抗剂(antagomir)于ISO诱导的大鼠原代心肌细胞中使miR-153-3p低表达,根据转染情况分为空白组,ISO组（药物诱导组）,ISO+NC组（阴性对照组）和ISO+miR-153-3p antagomir组（实验处理组）;用FITC Phalloidin FITC标记鬼笔环肽染色观察细胞表面积的变化,荧光定量PCR(real-time quantitative PCR,RT-qPCR)法检测心房利钠肽,β-肌球蛋白重链和miR-153-3p基因的表达。结果 在一定时间内随着ISO诱导时间的延长心肌细胞肥大效果逐步升高,到18 h和24 h呈显著差异（P<005）,48 h后细胞肥大效果降低;miR-153-3p的表达量与肥大效果呈一致趋势,表面积结果与RT-qPCR结果一致。结论 MiR-153-3p在大鼠心肌细胞中响应ISO诱导上调,并且敲低miR-153-3p显著降低心肌细胞的肥大效果。表明miR-153-3p是心肌肥大的重要调节因子,敲低miR-153-3p有抑制心肌肥大的作用,揭示了miRNA在控制心肌肥大发展中的新信号机制。