Expression and functional characterization of the adhesion molecule spermatogenic immunoglobulin superfamily in the mouse testis.
ABSTRACT Spermatogenic immunoglobulin superfamily (SgIGSF) is a mouse protein belonging to the immunoglobulin superfamily expressed in the spermatogenic cells of seminiferous tubules. We produced a specific polyclonal antibody against SgIGSF. Western blot analysis of the testes from postnatal developing mice using this antibody demonstrated multiple immunopositive bands of 80-130 kDa, which increased in number and size with the postnatal age. Enzymatic N-glycolysis caused reduction in the size of these bands to 70 kDa, indicating that SgIGSF is a glycoprotein and its glycosylation pattern and extent are developmentally regulated. Immunohistochemical analysis of the adult testis demonstrated that SgIGSF was present in the spermatogenic cells in the earlier steps of spermatogenesis and increased in amount from intermediate spermatogonia through zygotene spermatocytes but was diminished in the steps from early pachytene spermatocytes through round spermatids. After meiosis, SgIGSF reappeared in step 7 spermatids and was present in the elongating spermatids until spermiation. The immunoreactivity was localized primarily on the cell membrane. Consistent with the findings in adult testes, the analysis of the developing testes revealed that SgIGSF was expressed separately in the spermatogenic cells in earlier and later phases. Sertoli cells had no expression of SgIGSF, whereas both SgIGSF immunoprecipitated from the testis lysate and produced in COS-7 cells was shown to bind to the surface of Sertoli cells in primary culture. These results suggested that SgIGSF on the surface of spermatogenic cells binds to some membrane molecules on Sertoli cells in a heterophilic manner and thereby may play diverse roles in the spermatogenesis.
Acta histochemica et cytochemica official journal of the Japan Society of Histochemistry and Cytochemistry 12/2014; DOI:10.1369/0022155414564870 · 1.22 Impact Factor
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ABSTRACT: Autonomic neurons innervate pancreatic islets of Langerhans and maintain blood glucose homeostasis by regulating hormone levels. We previously showed that cell adhesion molecule 1 (CADM1) mediated the attachment and interaction between nerves and aggregated pancreatic islet α cells. In this study, we cocultured αTC6 cells, a murine α cell line, with mouse superior cervical ganglion (SCG) neurons. The oscillation of intracellular Ca(2+) concentration ([Ca(2+)]i) was observed in 27% and 14% of αTC6 and CADM1-knockdown αTC6 cells (αTC6(siRNA-CADM1) cells) in aggregates, respectively, within 1 min after specific SCG nerve stimulation with scorpion venom. In αTC6(siRNA-CADM1) cells, the responding rate during 3 min after SCG nerve stimulation significantly increased compared with that within 1 min, whereas the increase in the responding rate was not significantly different in αTC6 cells. This indicated that the response of αTC6 cells according to nerve stimulation occurred more rapidly and effectively than that of αTC6(siRNA-CADM1) cells, suggesting CADM1 involvement in promoting the interaction between nerves and α cells and among α cells. In addition, because we found that neurokinin (NK)-1 receptors, which are neuropeptide substance P receptors, were expressed to a similar extent by both cells, we investigated the effect of substance P on nerve-α cell interaction. Pretreatment with CP99,994 (0.1 μg/ml), an NK-1 receptor antagonist, reduced the responding rate of both cells, suggesting that substance P released from stimulated neurites was a mediator to activate αTC6 cells. In addition, α cells that were attached to neurites in a CADM1-mediated manner appeared to respond effectively to neurite activation via substance P/NK-1 receptors.Biochemical and Biophysical Research Communications 07/2013; DOI:10.1016/j.bbrc.2013.07.082 · 2.28 Impact Factor