Secretome Analysis of Testicular Peritubular Cells: A Window into the Human Testicular Microenvironment and the Spermatogonial Stem Cell Niche in Man
Secretome Analysis of Testicular Peritubular Cells: A Window into the Human Testicular Microenvironment and the Spermatogonial Stem Cell Niche in Man
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DOI：
10.1021/pr400769z
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发表时间：
2014-03-01
影响因子：
4.4
通讯作者：
Arnold, Georg J.
中科院分区：
文献类型：
--
作者：
Flenkenthaler, Florian;Windschuettl, Stefanie;Arnold, Georg J.
精原干细胞（ssc）对人类终身精子发生至关重要。在它们的生态位中，一种特殊的生长因子环境和周围细胞的结构支持被认为确保了它们的维持。在人类中，精管壁的细胞，人类睾丸小管周围细胞（HTPCs），被认为通过分泌蛋白质来促进这种微环境和整个睾丸微环境。因此，采用LC-MS/MS对5名男性HTPCs培养的分泌组进行分析。对HTPC裂解物的蛋白质组进行定量和比较，发现660个鉴定的分泌组蛋白中有263个在培养基中至少富集了5倍。为了获得更多的分泌证据，信号肽和基因本体（GO）富集分析应用。后者显示除了细胞外基质（ECM）成分外，在信号通路中作用的趋化因子和生长因子显着过度代表，这些信号通路对SSC的维持至关重要。用人睾丸切片进行免疫组织化学，描绘了选定蛋白在体内的表达。细胞粘附和迁移相关蛋白的显著富集可能表明它们参与了SSC的调控。我们的数据有力地支持了HTPCs在人类SSC生态位组成中起关键作用的假设。
Spermatogonial stem cells (SSCs) are vital for lifelong spermatogenesis in man. In their niches, a special growth factor milieu and structural support by surrounding cells are thought to ensure their maintenance. In man, the cells of the wall of seminiferous tubules, human testicular peritubular cells (HTPCs), are considered to contribute to this microenvironment and the overall testicular microenvironment via secreted proteins. Therefore, the secretome of cultured HTPCs from five individual men was analyzed by LC-MS/MS. Quantification and comparison to the proteome of HTPC lysates revealed 263 out of 660 identified secretome proteins to be at least 5-fold enriched in the culture media. To obtain additional evidence for secretion, signal peptide and gene ontology (GO) enrichment analyses were applied. The latter revealed besides extracellular matrix (ECM) components a significant over-representation of chemokines and growth factors acting in signaling pathways that appear critical for SSC maintenance. Immunohistochemistry, performed with human testicular sections, depicted expression of selected proteins in vivo. The significant enrichment of proteins related to cell adhesion and migration may indicate their involvement in SSC regulation. Our data strongly support the hypothesis of a crucial role of HTPCs in the composition of SSC niches in man.