【摘要】：在生精小管中進(jìn)行的精子發(fā)生是一個(gè)復(fù)雜的成長(zhǎng)和成熟過(guò)程,有許多不同的原因會(huì)導(dǎo)致男性生殖細(xì)胞發(fā)育的失敗。隨著日益嚴(yán)峻的工作生活壓力和環(huán)境污染形勢(shì),正常育齡夫婦的不孕不育發(fā)病率在不斷的顯著上升。其中,由男性方面因素引起的病例約占50%,而且大多數(shù)病因不明。不孕不育癥已經(jīng)成為主要的臨床、社會(huì)和經(jīng)濟(jì)問(wèn)題。已有研究表明,由于遺傳因素異常而引發(fā)的生精障礙至少占男性不育的一半以上。因此,進(jìn)一步的研究男性不育產(chǎn)生的原因及分子機(jī)制,有助于提高男性不育的臨床診斷和治療。 支持細(xì)胞(Sertoli cell)位于生精小管的基底部,為生殖細(xì)胞的發(fā)育提供結(jié)構(gòu)上和功能上的支持。血睪屏障(Blood-testis barrier, BTB)由相鄰的支持細(xì)胞之間形成,為生殖細(xì)胞的正常發(fā)育提供一個(gè)穩(wěn)定的微環(huán)境,是睪丸的天然免疫屏障。在生精周期的第Ⅷ-Ⅺ期,前細(xì)線期/細(xì)線期的精母細(xì)胞會(huì)穿過(guò)血睪屏障以完成后續(xù)的精子發(fā)生。血睪屏障的破壞會(huì)導(dǎo)致睪丸免疫屏障的破壞,進(jìn)而引起不育。 之前的研究表明,近來(lái)研究表明,一些炎癥因子(如：TGF-β3,TNF-a和IL-1)在精子發(fā)生過(guò)程中可以調(diào)控血睪屏障的完整性,以利于前細(xì)線期／細(xì)線期精母細(xì)胞穿過(guò)血睪屏障。在睪丸中,IL-6可以抑制在生精上皮周期過(guò)程中減數(shù)分裂的DNA的合成,降低精子的運(yùn)動(dòng)能力,影響支持細(xì)胞對(duì)transferrin和inhibin B的分泌。在正常大鼠中,IL-6還可以通過(guò)阻斷MAPK14信號(hào)通路而破壞支持細(xì)胞緊密連接的通透性。但是,IL-6在調(diào)控血睪屏障中的功能卻不是很清楚。本論文的第一部分主要是對(duì)IL-6在影響血睪屏障動(dòng)力學(xué)方面的分子機(jī)制的探討。我們發(fā)現(xiàn)IL-6能夠破壞血睪屏障的完整性,改變血睪屏障膜整合蛋白在細(xì)胞中的正常定位和表達(dá)水平。進(jìn)一步的研究發(fā)現(xiàn),IL-6可以通過(guò)抑制血睪屏障組成蛋白的降解和激活ERK-MAPK信號(hào)通路來(lái)調(diào)控血睪屏障。我們的研究為闡明IL-6在調(diào)控血睪屏障完整性的功能研究提供了新的分子機(jī)制。 擬染色小體(Chromatoid body, CB),是一種雄性生殖細(xì)胞所特有的云狀結(jié)構(gòu)。擬染色小體在粗線期精母細(xì)胞的細(xì)胞質(zhì)中以位于線粒體簇空隙中的纖維狀顆粒結(jié)構(gòu)的形式首次出現(xiàn),到圓形精細(xì)胞時(shí)期壓縮形成一個(gè)單一的、纖維狀的核周顆粒,在長(zhǎng)形精細(xì)胞時(shí)期逐漸消失。由于其中含有大量的蛋白質(zhì)、mRNAs和非編碼RNA,擬染色小體被認(rèn)為是雄性生殖細(xì)胞所特有的RNA存儲(chǔ)和加工中心。雖然擬染色小體被發(fā)現(xiàn)了一百多年,但是其在精子發(fā)生過(guò)程和男性不育中的具體功能是什么現(xiàn)在還不是很清楚。在小鼠中,擬染色小體的成分敲除后會(huì)導(dǎo)致小鼠不育,因此推測(cè)擬染色小體可能在精子發(fā)生過(guò)程和男性不育中發(fā)揮重要的功能。 KH-type剪切調(diào)控蛋白(KH-type splicing regulatory protein, KSRP)在體細(xì)胞中可以調(diào)控基因表達(dá)和一些特定的microRNAs的成熟。但是KSRP蛋白在精子發(fā)生過(guò)程和男性不育方面的功能卻知之甚少。本論文的第二部分研究,主要是探討KSRP蛋白在精子發(fā)生過(guò)程中所起到的功能。我們發(fā)現(xiàn)KSRP蛋白在睪丸中是核質(zhì)蛋白,可以定位在擬染色小體上,是擬染色小體的一種新的組成成分。KSRP蛋白可以通過(guò)與擬染色小體蛋白PABP1和PABP2以及擬染色小體中的mRNAs和microRNA的相互作用,進(jìn)而可能參與到單倍體生殖細(xì)胞中mRNAs的翻譯和microRNA的加工成熟調(diào)控。KSRP蛋白還可以在miRNA-182的介導(dǎo)下完成與擬染色小體蛋白Ddx5的結(jié)合,進(jìn)而參與調(diào)控?cái)M染色小體的組織。此外,我們發(fā)現(xiàn)在KSRP基因敲除小鼠和寡精癥患者的睪丸組織中擬染色小體的組成成分的異常表達(dá)。因此,我們的研究結(jié)果為理解KSRP蛋白在精子發(fā)生和擬染色小體中的功能提供了新的分子機(jī)制。
[Abstract]:Spermatogenesis in the seminiferous tubules is a complex growth and maturation process, with many different causes leading to the failure of male germ cell development. With the increasing pressure of working life and environment pollution, the incidence of infertility in the regular and married couples is increasing significantly. Among them, the number of cases due to male factors is about 50%, and most of the causes are unknown. Infertility has become a major clinical, social and economic issue. The research has shown that the spermatogenic disorder caused by the abnormality of the genetic factors at least accounts for more than half of the male infertility. Therefore, a further study of the causes and molecular mechanisms of male infertility can help to improve the clinical diagnosis and treatment of male infertility. The support cell (Sertoli cell) is located at the base of the spermatogenic tubule, providing structural and functional support for the development of the germ cells. The blood-testis barrier (BTB) is formed between adjacent supporting cells, providing a stable microenvironment for the normal development of the germ cells, which is the natural immune screen of the testis. Barrier. The spermatocytes in the pre-fine-line/ fine-line phase will pass through the blood-testis barrier to complete subsequent sperm delivery during the period VIII-1 of the spermatogenic cycle. The destruction of the blood-to-testis barrier can lead to the destruction of the immune barrier of the testis, which in turn causes no damage. The previous studies have shown that recent studies have shown that some inflammatory factors (e.g., TGF-3, TNF-a and IL-1) can regulate the integrity of the blood-testis barrier during spermatogenesis, to facilitate the passage of the pre-fine line/ fine-line spermatocytes through the blood In the testis, IL-6 can inhibit the synthesis of meiosis in the process of spermatogenic epithelium, reduce the motility of the sperm, and affect the support of the cells to transferrin and inhibin B. In normal rats, IL-6 can also destroy the tight junction of the support cells by blocking the MAPK14 signaling pathway. Permeability. However, the function of IL-6 in regulating the blood-testis barrier is not It is clear that the first part of this paper is mainly the molecular mechanism of IL-6 in the dynamics of the blood-testis barrier. We found that IL-6 can destroy the integrity of the blood-testis barrier and change the normal localization of the whole protein of the blood-testis barrier membrane in the cell. Further study found that IL-6 can regulate blood by inhibiting the degradation and activation of the ERK-MAPK signal pathway of the blood-testis barrier component. The testis barrier. Our study provides a new division of the functional study of IL-6 in regulating the integrity of the blood-testis barrier Submechanism. The species of the species to be dyed (CB) is a characteristic of a male germ cell. The structure of the cloud-like structure is the first appearance of the structure of the fibrous structure in the cytoplasm of the spermatocytes of the coarse line, which is located in the space of the mitochondrial cluster, and is compressed to form a single, fibrous, nuclear-like particle in the period of the round sperm cell, and in the case of the long-form fine cell, As a result of the fact that a large amount of protein, mRNAs, and non-coding RNAs, the pseudo-staining bodies are thought to be the specific RNA storage of the male germ cells and the processing center. Although the pseudo-stained body has been found for more than a hundred years, its specific function in the spermatogenesis and male infertility is now It is not clear. In the mouse, the component of the pseudo-stained body is knocked out to cause the mouse to be sterile, so it is presumed that the pseudo-stained body may play a role in the spermatogenesis and in the male infertility. KH-type cleavage regulatory protein (KSRP) can regulate gene expression and specific micro-micro in somatic cells. The maturation of the RNAs, but the KSRP protein is in the process of spermatogenesis and male infertility. Little is known about the function. The second part of this paper is to study the genesis of the KSRP protein in the spermatogenesis. We found that the KSRP protein is a nuclear protein in the testis, can be positioned on the pseudo-stained body, and is the one that is to be dyed. The KSRP protein can be involved in the translation and microRNA of mRNAs in the haploid germ cells by the interaction with the mRNAs and microRNAs in the pseudo-stained body proteins PABP1 and PABP2 and the pseudo-stained bodies. The KSRP protein can also be combined with the pseudo-stained body protein Ddx5 under the mediation of the miRNA-182, and further participate in the regulation and control. The tissue of the stained body. In addition, we found the composition of the bodies to be dyed in the testis of the KSRP gene knockout mice and oligospermia. Therefore, the results of our study are to understand the function of the KSRP protein in the spermatogenesis and the pseudo-stained body.
【學(xué)位授予單位】：中國(guó)科學(xué)技術(shù)大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：R698.2

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本文編號(hào)：2493116