Role of mitochondrial microRNAs (mitomiRs) in endogenous renal repair

线粒体 microRNA (mitomiRs) 在内源性肾修复中的作用

• 批准号: 10471652
• 负责人: Alfonso Eirin
• 金额: $ 10万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-17 至 2022-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10471652
• 关键词: 3-Dimensional; Address; Attenuated; Biogenesis; Biological Assay; Cell Nucleus; Cell physiology; Cells; Characteristics; Cytosine; Cytosol; Data; Deterioration; Development; Dioxygenases; Disease; Elderly; End stage renal failure; Enhancers; Enzymes; Epigenetic Process; Epithelial Cells; Exhibits; Family suidae; Fibrosis; Functional Imaging; Functional disorder; Gene Expression; Gene Silencing; Genes; Genetic Transcription; Harvest; Histones; Hypertension; Imaging Techniques; Impairment; In Vitro; Inflammation; Infusion procedures; Injury to Kidney; Kidney; Kidney Diseases; Measures; Mediating; Methylation; MicroRNAs; Mitochondria; Mitochondrial DNA; Morbidity - disease rate; Nucleic Acid Regulatory Sequences; Oxidation-Reduction; Phenotype; Polyribonucleotide Nucleotidyltransferase; Population; Process; Production; Proliferating; Protein Import; Regulator Genes; Renal Artery Stenosis; Renal function; Ribonuclease III; Role; Structural defect; Structure; System; Techniques; Testing; Tubular formation; Untranslated RNA; cell injury; clinically relevant; experimental study; genome-wide; improved; in vivo; inhibitor/antagonist; injured; insight; kidney repair; migration; mortality; novel; novel strategies; oxidation; paracrine; porcine model; preservation; progenitor; promoter; protective effect; renal ischemia; repaired; reparative capacity; tool

Renal artery stenosis (RAS) remains a common cause of hypertension and end-stage renal disease in the elderly population, associated with increased morbidity and mortality. Recent data suggest that renal ischemia in RAS interferes with endogenous kidney repair mechanisms, such as CD133+/CD24+ scattered tubular-like cells (STCs), which can proliferate and their progeny re-differentiate into tubular epithelial cells to replace lost neighboring injured tubular cells. Our previous studies have shown that experimental RAS impairs the reparative capacity of swine STCs by inducing structural and functional abnormalities in their mitochondria. However, the processes underpinning RAS-induced STC mitochondrial damage remain unclear. Micro-RNAs (miRNAs) are non-coding RNA fragments that function as post-transcriptional regulators of gene expression. MiRNA genes are transcribed in the nucleus, which results in the production of pri- and pre- miRNA precursors, and subsequently mature miRNAs. Although most mature miRNAs are present in the cytosol, few miRNAs, known as ‘mitomiRs’, translocate to the mitochondrion to silence gene expression related to mitochondrial functions. Our preliminary data show that RAS increases expression of mitomiRs in swine STCs, associated with decreased expression of mitochondrial DNA (mtDNA) genes, and in turn mitochondrial structural abnormalities and dysfunction. Our pilot experiments also show that the promoters and enhancers of mitomiRs exhibit hyper 5-hydroxymethylation of cytosine (5hmC), an epigenetic mark generated by the oxidation of 5mC by the ten- eleven translocation methylcytosine dioxygenase (TET). Possibly, renal ischemia in RAS may alter mitomiR biogenesis and interfere with mitochondrial function in STCs. This might be partly mediated by epigenetic processes (5hmC) within mitomiR regulatory regions and/or increased import of mitomiRs into mitochondria. The working hypothesis underlying this proposal is that altered mitomiR expression in STCs underlies RAS-induced STC mitochondrial damage, blunting the paracrine function and capacity of STCs to preserve the post-stenotic kidney. Three specific aims will be pursued: Aim 1: will test whether increased mitomiR expression in RAS-STCs induces mitochondrial structural damage and dysfunction in STCs. Aim 2: will test whether RAS imposes epigenetic changes that increase mitomiR expression in STCs. Aim 3: will test whether aberrant mitomiR mitochondrial import contributes to STC dysfunction. Successful studies will provide novel insight into the vulnerability of this repair system and may contribute towards development of feasible clinically relevant tools for improving the utility and efficacy of kidney repair in renal disease.

肾动脉狭窄(RAS)仍然是高血压和终末期肾病的常见原因。 老年人口，与发病率和死亡率增加有关。最近的数据表明，肾脏缺血 RAS干扰内源性肾脏修复机制，如CD133+/CD24+散在小管样 可以增殖的细胞(STCs)及其后代重新分化为肾小管上皮细胞以取代丢失的细胞 邻近受损的肾小管细胞。我们之前的研究表明，实验性的RAS损害了 通过诱导线粒体结构和功能异常来提高猪干细胞的修复能力。 然而，RAS诱导STC线粒体损伤的过程尚不清楚。 MicroRNAs(MiRNAs)是一种非编码的RNA片段，其功能是转录后调节 基因表达。MiRNA基因在细胞核中转录，这导致Pri-和Pre-DNA的产生 MiRNA前体，以及随后成熟的miRNAs。尽管大多数成熟的miRNAs存在于 在胞浆中，少数miRNAs被称为“有丝分裂受体”，移位到线粒体以抑制相关基因的表达。 线粒体的功能。 我们的初步数据显示，RAS增加了猪STCs中有丝分裂受体的表达，与 线粒体DNA(MtDNA)基因表达减少，进而导致线粒体结构异常 和功能障碍。我们的初步实验还表明，有丝分裂受体的启动子和增强子表现出高度的 胞嘧啶的5-羟甲基化(5hmC)，一种表观遗传标记，由5 mC被10-HmC氧化而产生- 转位甲基胞嘧啶双加氧酶(Tet)11例。RAS肾缺血可能改变有丝分裂原受体 STCs的生物发生和干扰线粒体功能。这可能在一定程度上是由表观遗传调节的。 在有丝分裂受体调节区内的过程(5hmC)和/或增加有丝分裂受体进入线粒体。 支持这一提议的工作假设是，STC中丝裂原受体表达的改变是 RAS诱导STC线粒体损伤，钝化STC的旁分泌功能和能力 保留狭窄后的肾脏。将追求三个具体目标：目标1：将测试是否增加 RAS-STCs中丝裂原受体的表达可导致STCs线粒体结构损伤和功能障碍。目标2： 将测试RAS是否会施加表观遗传变化，从而增加STC中有丝分裂受体的表达。目标3：意志测试 线粒体的异常输入是否导致STC功能障碍。成功的研究将提供 对此修复系统的脆弱性的新见解，并可能有助于开发可行的 提高肾脏修复在肾脏疾病中的实用性和有效性的临床相关工具。