Leydig Cells Express Neural Cell Adhesion Molecules in Vivo and in Vitro1

Abstract

1bc neural cdI adbcsioo molccule (NCAM) polypepddes are aprascd by numerous tisIues durina embryool.c devdopment, wberc tbey are InvolYed In cdI<dl interIctioos. In tbe adult, NCAM aprasion Is coo8ned to a fcw cdI types, includiog llCUIOIII and peptide-bormone-produc:ing cells. Here wc demoostrate tbat the Leydig cdls of tbe adult rat, mouse, and bamster testes opress NCAM as wdl. Western blottlng lIbowed tbat an NCAM of appt'Oldmatdy 120 kDa was present In tbe adult testes of all three spedes Investlpted. 1bls form was also found In fresbly Isolated mouse Leydig cdls and In Leydig cdls aftcr 2 days In culture. After 4 days In culture, mouse Leydig ceIIs aprascd additional NCAM Isoforms of appt'Oldmatdy 140 and 180 kDa, Indic:atlng c:han&es In alternative splidni of NCAM primary traIIICripts. Also, NCAM mRNA of alllsoforms, as detected by 51ßudease protectioo a.ays, Inc:rased witb time In culture. 1bc aprasion of tbe cdI adbcsioo molecule NCAM by adult Leydig cdls may cxplaIn tbe agregatioo of Leydig ceIIs In clusters In rodent testes, wbic:b could be a prcrcqWsite for ftmctiooal coordination of groups of Leydig cells. Furthermore, tbe presence of tbIs neural and endocrIne markcr may Indicate a dOller re-Iadoosbip betwcen Leydig ceIIs and neural and peptide-bormooe-produdni ceIIs tban Is considered to c:xIst at tbe present time.

Neural cell adhesion molecule immunoreactivity in Merkel cells and Merkel cell tumours

“…However, since the immunostaining was not restricted to synaptic areas of the receptor cells, other authors postulate that it cannot be argued that NCAM participates in synaptic formation [39]. NCAM has also been described in multiple endocrine and neuroendocrine cells including pituitary cells, adrenal cells, pancreatic islet cells, thyroid C cells, testicular Leydig cells, ovarian granulosa cells and pulmonary neuroendocrine cells [5,12,17,19,20,21,23,24,28,30,33,37]. Since most of these cells lack contacts with nerve fibres, NCAM cannot obviously act in nerve-cell recognition in these cases.…”

Barrier properties of testis microvessels.

“…Such contribution of the endothelium is presumably in series and complements the epithelial component(s) of the BTB that is formed by the tight junctions among Sertoli cells. (50,51), suggesting that they, like astrocytes, are of ectodermal origin. Previously, S-100, a marker of astrocytes (25), was demonstrated in Leydig cells (52).…”

Expression and alternative splicing of the neural cell adhesion molecule NCAM in human granulosa cells during luteinization

“…Based on the data of all these studies, NCAM-140 could be involved in cell-to-cell adhesion (granulosa cells in the growing follicle), as well as cell separation (antrum formation). In most previous studies NCAM has been suggested to play a role in the autoadhesion of NCAMbearing cells of the same kind via a homophilic binding, such as in the endocrine cells of the pancreatic islet, in the adenohypophysis, in adrenal cortex, adrenal medulla and in the testis [10,15]. In these cases the 'recognition site' of NCAMs, which was identified as lying within the third Ig domain [8], may be modulated by alternative splicing of the neighbouring fourth Ig domain.…”

“…NCAMs were first found in the nervous system, but subsequently were also found in polypeptide hormoneand steroid-producing endocrine cells [10][11][12][13][14][15]. NCAMs allow the formation of cell clusters by auto-adhesion of neighboring NCAM-bearing cells.…”