植物激素相关microRNA研究进展

microRNA（miRNA）是22nt左右的非编码RNA,主要在转录后水平调节基因的活性。miRNA通过与靶基因的互补位点结合从而降解靶基因mRNA或抑制其翻译。近年的研究发现,miRNA在植物生长发育中发挥着重要的调控作用。目前已知一些miRNA参与植物激素信号途径的切入点,这为我们了解miRNA和植物激素在植物发育中的作用提供了新思路。本文综述了miRNA参与植物激素信号应答及生物合成的研究进展,并对一些miINA在植物激素信号应答中可能的作用进行了讨论。     

A novel regulatory facet for hypertriglyceridemia: The role of microRNAs in the regulation of triglyceride-rich lipoprotein biosynthesis

Atherosclerotic cardiovascular disease (ASCVD) is one of the major leading global causes of death. Genetic and epidemiological studies strongly support the causal association between triacylglycerol-rich lipoproteins (TAGRL) and atherogenesis, even in statin-treated patients. Recent genetic evidence has clarified that variants in several key genes implicated in TAGRL metabolism are strongly linked to the increased ASCVD risk. There are several triacylglycerol-lowering agents; however, new therapeutic options are in development, among which are miRNA-based therapeutic approaches. MicroRNAs (miRNAs) are small non-coding RNAs (18–25 nucleotides) that negatively modulate gene expression through translational repression or degradation of target mRNAs, thereby reducing the levels of functional genes. MiRNAs play a crucial role in the development of hypertriglyceridemia as several miRNAs are dysregulated in both synthesis and clearance of TAGRL particles. MiRNA-based therapies in ASCVD have not yet been applied in human trials but are attractive. This review provides a concise overview of current interventions for hypertriglyceridemia and the development of novel miRNA and siRNA-based drugs. We summarize the miRNAs involved in the regulation of key genes in the TAGRLs synthesis pathway, which has gained attention as a novel target for therapeutic applications in CVD.     

MicroRNAs as regulators in normal hematopoietic and leukemia stem cells: current concepts and clinical implications

Relapse after current treatment is one of the main limitations to the complete cure of leukemia, and a concept that leukemia stem cell (LSC) is the major cause of relapse has been proposed. LSCs are derived from normal hematopoietic stem cells (HSCs), residing at the apex of leukemia cells and hiding in the bone marrow (BM) niche to evade chemotherapy. Novel therapy is strongly needed based on the unique features of LSCs to directly target these cells. MicroRNAs (miRNAs), a class of small non-coding RNAs, are now known to play important roles on cancer stem cell maintenance and differentiation. Because of the ability of miRNAs to inactivate either specific genes or entire gene families, strategies based on differential expression levels of miRNAs in LSCs as dominant activators or suppressors of gene activity have emerged as promising new candidate approaches for eradicating LSCs. In this review, we highlight new findings regarding the roles of miRNAs in LSC maintenance of quiescence repression, self-renewal, surface marker targeting, and the LSCBM niche interaction. We also discuss recent advances and future challenges to use LSC specific miRNAs as potential therapeutic molecules in eradicating LSCs.     

Role of MicroRNAs and small RNAs in regulation of developmental processes and agronomic traits in Gossypium species

Small RNAs (sRNAs) are short, non-coding, 17–24 nucleotides long RNA molecules that play vital roles in regulating gene expression in every known organism investigated to date including cotton (Gossypium ssp.). These tiny RNA molecules target diverse categories of genes from different bioliogical and metabolic processes and have been reported in the three domains of life. Small RNAs, including miRNAs, are involved in ovule and fiber development, biotic and abiotic stresses, fertility, and other biochemical processes in cotton species. Also, sRNAs are the critical components in RNA interference pathway. In this article, we have reviewed the research efforts related to the isolation and characterization of miRNAs using molecular and genomic approaches. The progress made in understanding the functional roles of miRNAs in regulation, alteration, and inactivation of fundamental plant processes and traits of importance in cotton are presented here.     

植物miRNA参与调控作物农艺性状的研究进展

植物microRNA (miRNA)是一类长度约为20～24 nt的内源非编码小RNA,它们通过在转录后水平调控靶基因的表达,在植物的生长发育、逆境响应和环境适应等过程中起着关键作用. miRNA对水稻、玉米、大豆等重要经济作物的农艺性状也起着重要的调控作用,在改良农作物性状上具有重大的应用潜能.本文重点介绍了参与作物农艺性状(如株型、花期、种子发育及抗逆等)调控的关键miRNA及其调控途径,同时总结了miRNA参与作物性状改良的主要研究方法和手段,并讨论了miRNA在作物性状改良应用中的前景.     

miRNA在植物发育与环境适应性中的作用

植物miRNA是广泛分布于植物基因组的非编码小分子RNA．是真核生物基因表达的一类负调控因子,主要通过指导靶基因的切割或降低靶基因的翻译从转录后水平上来抑制植物基因表达．从而影响植物形态发生、发育过程和适应环境的能力。本文综述了植物miRNA形成、作用机理、功能等方面研究的最新进展,总结了现有miRNA研究方法的优缺点,提出了miRNA在植物适应养分和元素毒害胁迫过程中的调节作用．拓宽了该领域研究的思路。     

Cervical cancer development,chemoresistance, and therapy: a snapshot of involvement of microRNA

Cervical cancer (CC) is one of the leading causes of death in women due to cancer and a major concern in the developing world. Persistent human papilloma virus (HPV) infection is the major causative agent for CC. Besides HPV infection, genetic and epigenetic factors including microRNA (miRNA) also contribute to the malignant transformation. Earlier studies have revealed that miRNAs participate in cell proliferation, invasion and metastasis, angiogenesis, and chemoresistance processes by binding and inversely regulating the target oncogenes or tumor suppressor genes. Based on functions and mechanistic insights, miRNAs have been identified as cellular modulators that have an enormous role in diagnosis, prognosis, and cancer therapy. Signatures of miRNA could be used as diagnostic markers which are necessary for early diagnosis and management of CC. The therapeutic potential of miRNAs has been shown in CC; however, more comprehensive clinical trials are required for the clinical translation of miRNA-based diagnostics and therapeutics. Understanding the molecular mechanism of miRNAs and their target genes has been useful to develop miRNA-based therapeutic strategies for CC and overcome chemoresistance. In this review, we summarize the role of miRNAs in the development, progression, and metastasis of CC as well as chemoresistance. Further, we discuss the diagnostic and therapeutic potential of miRNAs to overcome chemoresistance and treatment of CC.

     

Small RNAs in regulating temperature stress response in plants

Due to global climate change, temperature stress has become one of the primary causes of crop losses worldwide. Much progress has been made in unraveling the complex stress response mechanisms in plants, particularly in the identification of temperature stress responsive protein‐coding genes. Recently discovered microRNAs (miRNAs) and endogenous small‐interfering RNAs (siRN As) have also been demonstrated as important players in plant temperature stress response. Using high‐throughput sequencing, many small RNAs, especially miRNAs, have been identified to be triggered by cold or heat. Subsequently, several studies have shown an important functional role for these small RNAs in cold or heat tolerance. These findings greatly broaden our understanding of endogenous small RNAs in plant stress response control. Here, we highlight new findings regarding the roles of miRNAs and siRNAs in plant temperature stress response and acclimation. We also review the current understanding of the regulatory mechanisms of small RNAs in temperature stress response, and explore the outlook for the use of these small RNAs in molecular breeding for improvement of temperature stress tolerance in plants.     

癌症相关microRNA与靶基因的生物信息学分析

MicroRNAs(miRNAs)是一类长度约为22nt的内源性非编码RNA,通过与靶基因转录本互补结合调控基因的表达。近年来,研究发现miRNA与癌症发生密切相关,miRNA可以直接充当癌基因或者抑癌基因而影响肿瘤的发生和生长。为更进一步揭示癌症相关miRNA的特征及靶基因的功能,文章通过数据库搜索及文献检索,在人类基因组中发现了475个癌症相关miRNA,系统地比较了癌症相关miRNA与非癌症miRNA以及基因内和基因间区癌症相关miRNA在保守性、SNP位点分布、癌谱及转录调控等特性。研究发现,癌症相关miRNA比非癌症miRNA保守性要强,发生SNP概率比较低,同时发现miRNA所涉及癌症数目与保守性成正相关。基因组定位分析发现,癌症相关miRNA比非癌症miRNA更倾向于成簇存在。进一步对宿主基因、癌症相关miRNA及作用的靶基因与癌症发生进行关联分析,发现一些非癌症miRNA的宿主基因倾向于被癌症miRNA作用。本研究结果为深入理解miRNA与癌症之间的关系,以及进一步为miRNA作为癌症诊断指示物提供理论依据。