长非编码RNA与糖尿病及其并发症

2型糖尿病是一种严重威胁人类健康的慢性非传染性代谢疾病,而胰岛素抵抗和胰岛β细胞功能衰竭被认为是其主要致病原因。在以往对糖尿病及其并发症发病机制的研究中,往往关注传统的蛋白编码基因(mRNA)。长链非编码RNA(long noncoding RNA,LncRNA)是一类长度大于200bp,不编码蛋白的RNA分子。近年来,越来越多的研究发现LncRNA在表观遗传、转录及转录后水平等多个层面上参与调控基因表达及代谢过程。本综述旨在讨论LncRNA在糖脂代谢调控、糖尿病及糖尿病并发症发生中作用的最新研究进展。     

LncRNA在糖尿病及其并发症中的作用

长链非编码RNA(long non-coding RNA,LncRNA)是一类转录本长度超过200个核苷酸、无蛋白质编码功能的RNA分子,起初认为它是转录过程中的副产物,无生物学功能。随着研究的不断推进,人们发现LncRNA不但在细胞增殖、分化和代谢中发挥重要的调节作用,而且还参与癌症、糖尿病、神经退行性疾病的病理进程。本文主要就LncRNA在糖尿病及其并发症中的作用作一综述。     

长非编码RNA与重大临床疾病

以往,人们对细胞和机体的生长发育及疾病发病机制的研究往往集中于蛋白质及其编码基因。近年来在通过对蛋白编码基因表观遗传水平、转录水平以及转录后水平的研究,越来越多的证据显示长非编码RNA(long noncoding RNA,LncRNA)在生长、发育以及疾病的发生发展中起重要的作用。人体基因组中约98%的基因转录组为非编码RNA,其中绝大部分为LncRNA,只有不足2%的编码基因最终经过转录翻译为蛋白质。最新的研究表明,人体中存在数万条LncRNA。目前,只有极少数LncRNA在细胞代谢及疾病发生中的作用被初步揭示,绝大部分的LncRNA的功能完全未知。进一步深入研究LncRNA的生物学功能,有可能为阐明许多重大疾病的发病过程及机制带来重大的突破,并提供独特的干预靶点。本综述简要讨论LncRNA与一些重大临床疾病关系的最新研究进展。     

长链非编码RNA-重编码调控因子与肿瘤的研究进展

长链非编码RNA(LncRNA)是一类长度超过200核苷酸且不编码蛋白质的RNA分子。肿瘤基因组学的快速发展使LncRNA在人类肿瘤研究方面的功能更加显著。基因间LncRNA(LincRNA)-重编码调控因子(ROR)作为一种新型LncRNA,其作用机制在结直肠癌、胰腺癌、乳腺癌的发生发展过程中有报道。我们就LincRNA-ROR在肿瘤中的相关调控机制以及在不同肿瘤中的研究现状做简要综述,以便对其有进一步了解。     

长链非编码RNA生物学功能及其意义研究进展

人类基因组DNA核苷酸序列中约93%能被转录为RNA,其中仅2%的转录产物被翻译为蛋白质,余下98%属于非编码RNA（non-coding RNA,ncRNA）。ncRNA中长度超过200 nt的称为长链非编码RNA（long non-coding RNA,LncRNA）,长期以来LncRNA被认为是转录过程中的副产物而不具有生物学功能。近年随着微小RNA（microRNA,miRNA）的研究进展,揭示了ncRNA在人类基因转录后调节、细胞生长、分化、增殖中起着相当重要的作用。同时也提示,相比miRNA,在细胞内转录比例更高的LncRNA具有极其复杂而重要的生物学功能,并与人类疾病密切相关。结合LncRNA的表观遗传学功能及其病理生理意义作一简述。     

长链非编码RNA 在乳腺癌中的研究进展

乳腺癌是女性最常见的恶性肿瘤之一,且其发病率呈逐年上升的趋势,尽管随着诊疗技术的进步,乳腺癌的死亡率得到了实质性的降低,但它仍是女性肿瘤死亡的第二大原因,目前对乳腺癌的治疗还面临很大的挑战。长链非编码RNA(Longnon-codingRNA,LncRNA)是一类长度超过200个核苷酸的非编码RNA分子,缺乏开放的阅读框,无编码蛋白质的功能。近年来研究发现,LncRNA可能在多种恶性肿瘤的发生、发展、侵袭及转移过程中起调控作用,且目前对其与乳腺癌的关系研究较多,对LncRNA与乳腺癌相关性的研究有望为乳腺癌的诊治提供新思路。现就LncRNA在乳腺癌中的研究进展做一综述。     

LncRNA的结构、功能及其与疾病的关系

70%的人类基因组能够被转录,而其中仅有1%～2%的转录本能够编码蛋白,余下98%均为非编码RNA（non-coding RNA,ncRNA）.在ncRNA中,长度大于200核苷酸称为长链非编码RNA（long non-coding RNA,LncRNA）,占全部ncRNA的80%～90%．LncRNA除了数量庞大以外,还具有表达量较低、物种间保守性较差及细胞表达特异性等特点,使LncRNA结构及作用机制等研究充满挑战．目前关于LncRNA的研究主要集中于功能方面．LncRNA能够广泛参与生物体的各种生理及病理过程,如表观遗传学调控、癌症、神经系统功能等．LncRNA作用机制众多,能够以分子诱饵、分子向导、分子支架及信号通路的调节剂等多种角色参与调节机体各种生物学过程．解析LncRNA的分子结构、深入研究其在生物体生理及病理过程中所发挥的作用,并揭示其作用机制,不仅能够加深对生物体生理及病理过程的认识,同时也能给某些疾病的诊断、防治提供新的思路及解决途径．本文综述了近年来有关LncRNA结构、功能及作用机制相关研究进展,以期为后续LncRNA相关研究提供参考.     

LncRNA与肝脏糖脂代谢的研究进展

长链非编码RNA(Long non-coding RNA,lncRNA)因参与多个层级上的生物进程而成为当下生命科学领域的研究热点.LncRNA可以与DNA、RNA和蛋白质等生物分子结合,并进一步影响靶基因的转录、翻译以及翻译后修饰等过程,从而发挥在细胞生理代谢过程中的调控作用.目前研究显示,lncRNA通过多种途径在...     

与眼部疾病相关的长链非编码RNA的研究进展

长链非编码RNA(long non-coding RNA,LncRNA)是一类长度大于200个核苷酸不具备编码蛋白质功能的转录子,在表观遗传、转录或转录后水平调节基因的表达,维持细胞稳态。研究表明多种LncRNA的表达失衡在肿瘤细胞的增殖、转移、干细胞的全能性、免疫细胞的发育及应答过程中发挥重要。新近的研究显示许多LncRNAs特异表达与眼部疾病发生密切相关。本文主要对目前报道的与眼部常见疾病如翼状胬肉、白内障、青光眼、糖尿病视网膜病变、眼部肿瘤等差异表达LncRNAs的功能和作用机制进行了综述,以期为LncRNAs作为眼部疾病的生物学标记和潜在治疗靶点的的应用提供参考资料。     

与眼部疾病相关的长链非编码RNA的研究进展

长链非编码RNA(long non-coding RNA,LncRNA)是一类长度大于200个核苷酸不具备编码蛋白质功能的转录子,在表观遗传、转录或转录后水平调节基因的表达,维持细胞稳态。研究表明多种LncRNA的表达失衡在肿瘤细胞的增殖、转移、干细胞的全能性、免疫细胞的发育及应答过程中发挥重要。新近的研究显示许多LncRNAs特异表达与眼部疾病发生密切相关。本文主要对目前报道的与眼部常见疾病如翼状胬肉、白内障、青光眼、糖尿病视网膜病变、眼部肿瘤等差异表达LncRNAs的功能和作用机制进行了综述,以期为LncRNAs作为眼部疾病的生物学标记和潜在治疗靶点的的应用提供参考资料。     

Embryo and Endosperm Function and Failure inSolanumSpecies and Hybrids

Although the importance of the endosperm as a food store inmany angiosperm seeds is well known, its significance duringearly embryogenesis has been neglected. In many interspecifichybrids, and in some other situations, embryos do not developfully and abort. It has often been stated that this is causedby the endosperm failing to conduct sufficient nutrients tothe embryo, but seldom has it been suggested that the endospermactively controls most of the early stages of morphogenesisof the embryo. Information gleaned from a broad survey of theliterature, combined with additional evidence presented here,obtained fromSolanum incanumand interspecific hybrids, indicatethat the endosperm is dynamic and very active in regulatingearly embryo development. This requires highly integrated geneticcontrol of rapidly changing metabolism in the endosperm. Ininterspecific hybrids, lack of coordination may cause unbalancedproduction of growth regulating substances by the endospermand hence abortion of the embryo, or even unregulated productionof nucleases and proteases resulting firstly in autolysis ofthe endosperm and then digestion of the embryo. The endospermmay thus serve to detect inappropriate hybridization of speciesor ploidy levels and so prevent waste of resources by producingseeds that would result in sterile hybrids or unthrifty subsequentgenerations. This discriminatory function of the endosperm hasdiminished during evolution and domestication of the crop plantSolanummelongenaL.Copyright 1998 Annals of Botany Company Solanum, embryo morphogenesis, endosperm, hybrid, seed development.     

HIFs and tumors--causes and consequences

For most organisms oxygen is essential fo life. When oxygen levels drop below those required to maintain the minimum physiological oxygen requirement of an organism or tissue it is termed hypoxia. To counter act possible deleterious effects of such a state, an immediate molecular response is initiated causing adaptation responses aimed at cell survival. This response is mediated by the hypoxia-inducible factor-1 (HIF-1), which is a heterodimer consisting of an alpha- and a beta-subunit. HIF-1 alpha protein is stabilized under hypoxic conditions and therefore confers selectivity to this response. Hypoxia is characteristic of tumors, mainly because of impaired blood supply resulting from abnormal growth. Over the past few years enormous progress has been made in the attempt to understand how the activation of the physiological response to hypoxia influences neoplastic growth. In this review some aspects of HIF-1 pathway activation in tumors and the consequences for pathophysiology and treatment of neoplasia are discussed.     

环腺苷酸应答元件结合蛋白与学习记忆

环腺苷酸(cAMP)应答元件结合蛋白(cAMP response element binding protein,CREB)是一种核转录因子,可与cAMP反应元件结合,调节基因转录,具有调节精子生成,昼夜节律,学习记忆等功能.近年来关于其在学习记忆中的作用成为医学研究热点.CREB是神经元内多条信息传递途径的汇聚点,参与长时记忆形成和突触可塑性.长时记忆(long-term memory)形成需依赖CREB介导的基因转录,干扰或抑制CREB活性可破坏长时记忆.长时程增强(long-term potentiation,LTP)是研究学习记忆的理想模型,在LTP诱导和维持过程中均可观察到CREB活性持续升高.但增龄过程中,海马CREB活性下降,影响学习记忆功能,与许多神经退行性疾病发生有关.     

Astrocytes and Synaptosomes Transport and Metabolize Lactate and Acetate Differently

Astrocytes transport the monocarboxylate acetate, but synaptosomes do not. The reason for this is unknown, because both preparations express monocarboxylate transporters (MCT). The transport and metabolism of lactate, another monocarboxylate, was examined in these two preparations, and the results were compared to those for acetate. Lactate transport is more rapid in astrocytes than in synaptosomes, but of lower affinity (Kms of 17 and 4 mM, respectively). Lactate (0.2 mM) is metabolized to CO2 more rapidly in synaptosomes than in astrocytes (rates of 0.37 and 0.07 nmol x mg protein(-1) x min(-1), respectively). The reason for this is unclear, but cellular differences in lactate dehydrogenase isotype expression may be involved. Acetate is metabolized to CO2 more rapidly in astrocytes than in synaptosomes (rates of 0.43 and 0.02 nmol x mg protein(-1) x min(-1), respectively). This is likely due to cellular differences in the expression of monocarboxylate transporter subtypes.