Lassila Markus, Juhila Juuso, Heikkilä Eija, Holthöfer Harry
Research Program in Molecular Medicine, Biomedicum, University of Helsinki, Helsinki, Finland.
Mol Reprod Dev. 2007 May;74(5):641-5. doi: 10.1002/mrd.20659.
Cell-cell interactions between Sertoli cells and germ cells are crucial for the maturation of germ cells in spermatogenesis but the structural and functional aspects of the interactions remain to be fully elucidated. Densin is a junction protein suggested to play a role in establishment of specific cell-cell contacts in the post-synaptic densities of the brain and the slit diaphragm of the kidney podocyte. In the present study, densin was discovered to be expressed in the testis of the man and the mouse. Expression of densin at the gene and the protein level was studied by using RT-PCR and Western blotting analyses, and the localization of densin was explored with immunofluorescence staining. RT-PCR and Western blotting analyses showed that densin is expressed at the gene and the protein levels. Immunofluorescence staining localized the expression of densin to the cell membranes of Sertoli cells suggesting that densin may be an adherens junction protein between Sertoli cells and developing germ cells. Densin is a novel testicular protein expressed in the cell membranes of Sertoli cells. Its functional role remains to be assessed.
支持细胞与生殖细胞之间的细胞间相互作用对于精子发生过程中生殖细胞的成熟至关重要，但这种相互作用的结构和功能方面仍有待充分阐明。致密素是一种连接蛋白，据推测在大脑突触后致密区和肾足细胞裂孔隔膜中特异性细胞间接触的建立中发挥作用。在本研究中，发现致密素在人和小鼠的睾丸中表达。通过逆转录聚合酶链反应（RT-PCR）和蛋白质印迹分析研究了致密素在基因和蛋白质水平的表达，并通过免疫荧光染色探索了致密素的定位。RT-PCR和蛋白质印迹分析表明致密素在基因和蛋白质水平均有表达。免疫荧光染色将致密素的表达定位在支持细胞膜上，这表明致密素可能是支持细胞与发育中的生殖细胞之间的黏附连接蛋白。致密素是一种在支持细胞膜上表达的新型睾丸蛋白。其功能作用仍有待评估。
