Isolation of male germ-line stem cells; influence of GDNF
Isolation of male germ-line stem cells; influence of GDNF
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DOI：
10.1016/j.ydbio.2004.12.006
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发表时间：
2005-03-01
影响因子：
2.7
通讯作者：
Dym, M
中科院分区：
文献类型：
--
作者：
Hofmann, MC;Braydich-Stolle, L;Dym, M
睾丸干细胞是A型精原细胞的一个亚群，其鉴定和物理分离对于我们理解其在精子发生的第一步中的生长调节至关重要。这些干细胞的特征仍然很差，因为缺乏特定的分子标记，使我们能够将它们与其他生殖细胞区分开来。因此，驱动精子发生第一步的分子机制仍然是未知的。在本研究中，我们表明，GFRalpha-1，GDNF（胶质细胞源性神经营养因子）的受体，强烈表达的一个子集的A型精原细胞在生精上皮的基底部分。利用这一特性，我们设计了一种方法，专门从未成熟的小鼠睾丸中分离这些GFR α-1阳性细胞。分离的细胞表达Ret，一种酪氨酸激酶跨膜受体，其通过GFR α-1介导对GDNF的细胞内应答。用rGDNF刺激后，分离的细胞在培养中增殖，并经历了生殖细胞分化的第一步。微阵列分析显示GDNF诱导了总共1124个基因的差异表达。在GDNF上调的基因中，有许多基因参与了哺乳动物的早期发育、分化和细胞周期。本报告描述了在睾丸中的GFR α-1-阳性细胞的纯群体的第一个分离，并确定可能在维持生殖系干细胞增殖和/或更新中发挥关键作用的信号通路。(C)2004年爱思唯尔公司All rights reserved.
The identification and physical isolation of testis stem cells, a subset of type A spermatogonia, is critical to our understanding of their growth regulation during the first steps of spermatogenesis. These stem cells remain poorly characterized because of the paucity of specific molecular markers that permit us to distinguish them from other germ cells. Thus, the molecular mechanisms driving the first steps of spermatogenesis are still unknown. We show in the present study that GFRalpha-1, the receptor for GDNF (glial cell line-derived neurotrophic factor), is strongly expressed by a subset of type A spermatogonia in the basal part of the seminiferous epithelium. Using this characteristic, we devised a method to specifically isolate these GFRalpha-1-positive cells from immature mouse testes. The isolated cells express Ret, a tyrosine kinase transmembrane receptor that mediates the intracellular response to GDNF via GFRalpha-1. After stimulation with rGDNF, the isolated cells proliferated in culture and underwent the first steps of germ cell differentiation. Microarray analysis revealed that GDNF induces the differential expression of a total of 1124 genes. Among the genes upregulated by GDNF were many genes involved in early mammalian development, differentiation, and the cell cycle. This report describes the first isolation of a pure population of GFRalpha-1-positive cells in the testis and identifies signaling pathways that may play a crucial role in maintaining germ-line stem cell proliferation and/or renewal. (C) 2004 Elsevier Inc. All rights reserved.