Sandlow J I, Feng H L, Cohen M B, Sandra A
Department of Urology, University of Iowa, Iowa City 52242-1089, USA.
J Androl. 1996 Jul-Aug;17(4):403-8.
The c-KIT proto-oncogene encodes for a transmembrane receptor and is associated with maturation of several cell types, including germ cells. The ligand of the receptor has been identified as stem cell factor (SCF). Loss or alteration of the expression of either of these factors leads to anemia, albinism, and/or sterility in mice. We examined the expression of c-KIT and SCF by immunohistochemistry in specimens from normal and infertile human testis. All specimens were obtained in the evaluation of male subfertility. We were able to demonstrate staining for c-KIT in Leydig cells in all specimens. Normal testis stained for c-KIT in the cytoplasm of early spermatogenic cells, as well as the acrosomal granules of the round spermatids and the acrosome of testicular spermatozoa. However, staining in testis demonstrating maturation arrest failed to demonstrate acrosomal staining, and Sertoli-only specimens demonstrated staining for c-KIT in Leydig cells only. The results for SCF demonstrated an overall uniform staining of Leydig cells in all specimens. The intensity of staining of Sertoli cells increased from normal to maturation arrest to Sertoli-only specimens. Germ cell staining was consistently negative. We hypothesize that these staining patterns for SCF are due to either lack of staining of the receptor-ligand complex or overexpression of the kit ligand in tissue that does not express the kit receptor. It appears that the c-kit receptor is expressed in the acrosome of developing germ cells, as well as in Leydig cells and early spermatogenic cells, suggesting a role in the acrosome reaction, as well as germ cell maturation and differentiation.
c-KIT原癌基因编码一种跨膜受体，与包括生殖细胞在内的多种细胞类型的成熟有关。该受体的配体已被确定为干细胞因子（SCF）。这两种因子中任何一种的表达缺失或改变都会导致小鼠出现贫血、白化病和/或不育。我们通过免疫组织化学检查了正常和不育人类睾丸标本中c-KIT和SCF的表达。所有标本均在评估男性亚生育力时获得。我们能够在所有标本的睾丸间质细胞中检测到c-KIT染色。正常睾丸在早期生精细胞的细胞质、圆形精子细胞的顶体颗粒以及睾丸精子的顶体中均检测到c-KIT染色。然而，显示成熟停滞的睾丸染色未显示顶体染色，仅支持细胞标本仅在睾丸间质细胞中检测到c-KIT染色。SCF的结果显示所有标本中的睾丸间质细胞总体染色均匀。支持细胞的染色强度从正常标本到成熟停滞标本再到仅支持细胞标本逐渐增加。生殖细胞染色始终为阴性。我们推测，SCF的这些染色模式是由于受体-配体复合物缺乏染色或在不表达kit受体的组织中kit配体过表达所致。似乎c-kit受体在发育中的生殖细胞的顶体以及睾丸间质细胞和早期生精细胞中表达，提示其在顶体反应以及生殖细胞成熟和分化中发挥作用。
