枸杞多糖对精原干细胞体外增殖的影响

背景：精原干细胞移植对不育具有潜在的临床应用价值,体外建立精原干细胞的培养系统获得数量较多的精原干细胞,仍是目前研究中亟待解决的问题。 目的：观察枸杞多糖对精原干细胞体外增殖的影响。 方法：采用两步酶消化法获取出生4~6 d雄性C57BL/6小鼠睾丸Sertoli细胞与精原干细胞,将精原干细胞接种在Sertoli细胞饲养层上,再加入枸杞多糖或联合细胞因子添加到细胞培养液中。1周后以流式细胞仪检测细胞周期及细胞活性率,并检测各组精原干细胞GFRa-1、Thy-1、c-kit的阳性率。 结果与结论：单独加入枸杞多糖后精原干细胞数量明显增加,增殖明显,联合加入胶质细胞源性神经营养因子与白血病抑制因子精原干细胞增殖更加明显(P < 0.05)。并发现体外培养1周后的精原干细胞仍保持其睾丸组织内的精原干细胞特征,大多仍维持在未分化状态。表明在枸杞多糖或枸杞多糖联合胶质细胞源性神经营养因子及白血病抑制因子作用下,可促进精原干细胞体外增殖。     

精原干细胞技术的研究进展

精原干细胞是精子形成的前体细胞，具有增殖、分化能力。随着精原干细胞移植技术、体外培养技术及冻存技术的成熟，使得精原干细胞的应用成为可能。在转基因动物、不孕症的治疗以及珍稀物种的保存等领域方面有着广阔的应用前景。     

生长因子对精原干细胞增殖、分化影响的研究现状

1精原干细胞的一般特性精原干细胞(Spermatogonial stem cell,SSC)位于睾丸曲细精管基膜上,细胞及核大,多呈圆形,核仁位于中央;胞质中有核糖体,线粒体丰富靠近核膜,呈圆形或椭圆形,内有板层状线粒体嵴,其余细胞器并不发达。它可分为A、B两型。在体内,A型精原细胞有3种命运:一是     

精原干细胞体外转化和转分化的研究进展

精原干细胞(SSC)在睾丸曲细精管内微环境的精确调控下,只能单向分化为精子。然而,SSC可在特定条件下转化为多能干细胞,甚至直接重编程转分化为功能性终末分化细胞。该特殊潜能使其在再生和精准医学领域具有很好的运用前景。     

精原干细胞技术的研究进展

精原干细胞是精子形成的前体细胞 ,具有增殖、分化能力。随着精原干细胞移植技术、体外培养技术及冻存技术的成熟 ,使得精原干细胞的应用成为可能。在转基因动物、不孕症的治疗以及珍稀物种的保存等领域方面有着广阔的应用前景     

骨髓间充质干细胞衍生的精原干细胞

近年来精原干细胞(spermatogonial stem cells,SSC)研究有两个具有重要意义的研究进展,一个进展是从新生小鼠[1]和成年小鼠睾丸[2]生殖细胞通过分离、基因分选、培养的SSC在胚胎干细胞(embryonic stem cells,ESC)培养条件下获得ESC特征,在离体条件下具有自发形成3个胚层的分化能力,在皮下注射这些细胞至免疫缺损小鼠,可以形成畸胎瘤;另一个进展是从骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSC)在离体培养条件下,通过基因挑选和改变培养条件可以衍生出具有精原干细胞和精原细胞分子特征的生殖细胞[3].     

精原干细胞的研究进展

精原干细胞的生物学特性、鉴定方法、体外培养及其细胞系的建立，在医学、生物工程学、遗传、转基因研究等方面有着广阔的应用前景。本文就精原干细胞的起源分类、生物学特性、实验研究等方面的最新研究进展进行踪述。     

精原干细胞研究新发现

据美国BIOCOMPARE科技新闻网(2004，11，8)报道，宾州大学的Ralph L．Brinster教授等人发现能使制造精子的精原干细胞(spermatagonial stem cells)长期培养的生长因子。研究人员表示，此发现将有助于未来生育治疗，提供干细胞来源，和进行基因修饰后再传给后代等过程。     

精原干细胞研究进展

在哺乳动物的雄性成体中,存在着数套自我更新的系统,但就物种延续而言,最重要的莫过于精子发生(spermatogenesis),它承担着雄性配子的产生和进化所必需的基因传递的作用.青春期启动后,精子发生贯穿整个雄性生命过程,其通过有序而且严格调控的细胞增殖和分化步骤而产生大量的精子,这一系统的基础便是精原干细胞(spermatogonial stem cells,SSCs).作为一种雄性生殖干细胞,精原干细胞是位于睾丸曲细精管生精上皮基膜上的As细胞,其前体是原始生殖细胞(primordial germ cell,PGCs).精原干细胞一方面可以自我增殖维持自身数目的相对恒定,另一方面可以经过数次有丝分裂后进入减数分裂,形成精母细胞,最终形成精子.而在此过程中,它还具有对可能的损伤维持更新的潜能和重新增殖的能力[1].精原干细胞的终生扩增性和永生性是产生雄性生殖细胞的保证,也使它成为生殖系中唯一在成年之后还能增殖的细胞.利用这一特性,精原干细胞可以作为成体多能性干细胞研究的前体.现对精原干细胞的体外培养、鉴定和目前进行的人类精原干细胞移植研究前景做简要概述.     

养精胶囊提取液对精原干细胞增殖的影响

BACKGROUND: Chinese herbs for kidney nourishment can promote the proliferation and differentiation of spermatogonial stem cells.     

生殖细胞核因子在精原干细胞体外培养分化中的表达

目的 将分离纯化的小鼠精原干细胞(SSCs)体外培养并诱导分化,检测生殖细胞核因子(GCNF)在小鼠SSCs诱导分化前后的表达.方法 用干细胞因子(SCF)诱导小鼠SSCs向精母细胞分化,通过间接免疫荧光染色和RT-PCR,检测GCNF在小鼠SSCs诱导分化前后的表达.结果 小鼠SSCs向精母细胞诱导分化前后,在倒置相差显微镜下进行形态学观察,细胞形态未发生明显变化,仍然呈圆形或椭圆形,核较大;间接免疫荧光及RT-PCR结果均显示,原代培养的小鼠SSCs呈现GCNF阴性,但是向精母细胞诱导分化2d后,GCNF开始表达.结论 GCNF在体外培养小鼠SSCs向精母细胞分化的早期有表达,提示GCNF可能参与了SSCs的早期分化.     

当归多糖对人白血病干细胞体外增殖与体内移植模型的影响

目的 探讨当归多糖(ASP)对人白血病干细胞(LSCs)增殖及体内移植的影响.方法 1.ASP 对CD34+CD38-人LSCs体外增殖的影响.免疫磁性法分选正常人和髓系白血病患者骨髓中CD34+CD38-细胞,分为正常CD34+CD38-对照组、CD34+CD38-LSCs对照组、正常CD34+CD38-ASP组和C...     

Effects of aging and niche microenvironment on spermatogonial stem cell self-renewal

Aging is evident in most tissues and organ systems, but the mechanisms of aging are difficult to identify and poorly understood. Here, we test the hypothesis that aging results in uncorrected defects in stem cell and/or niche function, which lead to system failure. We used the spermatogonial stem cell (SSC) transplantation assay to determine the effect of aging on testis stem cell/niche function in mice. Between 12 and 24 months of age, male mice experienced a declining level of fertility associated with decreased testis weight, level of spermatogenesis, and total stem cell content. However, when stem cells were consecutively passaged at 3-month intervals to testes of young males, these stem cells continued to produce spermatogenesis for more than 3 years. Thus, SSC self-renewal continues long past the normal life span of the animal when the stem cell is continually maintained in a young niche/microenvironment. Moreover, these data suggest that infertility in old males results from deterioration of the SSC niche and failure to support an appropriate balance between stem cell self-renewal and differentiation.     

Derivation and morphological characterization of mouse spermatogonial stem cell lines

Spermatogonial stem cells (SSCs), having yet to possess decisive markers, can only be detected retrospectively by transplantation assay. It was reported recently that mouse gonocytes collected from DBA/2 and ICR neonates propagated in vitro. This cultured germ cell, named the germline stem cell (GS cell), produced functional sperm to make progeny when transplanted into recipient mouse testes. Here we show that GS cell lines can be established not only from neonatal testes but also from the testis of adult mice. We also confirmed that GS cells once transplanted into a host testis can be recovered to resume in vitro expansion, indicating that they are convertible mutually with SSCs in adult testes. Confocal laser microscopic examination showed GS cells resemble undifferentiated spermatogonia in the adult testis. This unique cell line could be useful for research in germ cell biology and applicable as a new tool for the genetic engineering of animals.     

In vitro effect of acetyl-N-Ser-Asp-Lys-Pro (AcSDKP) analogs resistant to angiotensin I-converting enzyme on hematopoietic stem cell and progenitor cell proliferation

The tetrapeptide Acetyl-N-Ser-Asp-Lys-Pro (AcSDKP), an inhibitor of hematopoietic stem cell proliferation, is known to reduce in vivo the damage resulting from treatment with chemotherapeutic agents or ionizing radiation on the stem cell compartment. Recently, AcSDKP has been shown to be a physiological substrate of the N-active site of angiotensin I-converting enzyme (ACE). Four analogs of the tetrapeptide expressing a high stability towards ACE degradation in vitro have been synthesized in order to provide new molecules likely to improve the myeloprotection displayed by AcSDKP. These analogs are three pseudopeptides with a modified peptidic bond, Ac-Serpsi(CH2-NH)Asp-Lys-Pro, Ac-Ser-Asppsi(CH2-NH)Lys-Pro, Ac-Ser-Asp-Lyspsi(CH2-N)Pro, and one C-terminus modified peptide (AcSDKP-NH2). We report here that these analogs reduce in vitro the proportion of murine colony-forming units-granulocyte/macrophage in S-phase and inhibit the entry into cycle of high proliferative potential colony-forming cells. The efficacy of AcSDKP analogs in preventing in vitro primitive hematopoietic stem cells from entering into cycle suggests that these molecules could be new candidates for the powerful inhibition of hematopoietic stem and progenitor cell proliferation in vivo.