Expression of nerve growth factor and neurotrophin receptors in testicular cells suggest novel roles for neurotrophins outside the nervous system

1996 ◽  
Vol 8 (7) ◽  
pp. 1075 ◽  
Author(s):  
K Seidl ◽  
A Buchberger ◽  
C Erck
Keyword(s):  
Nerve Growth Factor ◽  
Growth Factor ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Leydig Cells ◽  
Expression Patterns ◽  
Myoid Cells ◽  
Nerve Growth ◽  
High Affinity ◽  
Ngf Receptor

The present study was designed to clarify the non-neurotrophic role for neurotrophins in mouse testis. By means of SI nuclease protection assay we could demonstrate that the gene coding for the low-affinity nerve growth factor (NGF) receptor p75NGFR is transiently expressed during germ cell development. Gene expression for p75NGFR was detected in late-meiotic spermatocytes and early spermatids and was found to be co-expressed with trkB and trkC, two tyrosine kinase receptors, commonly regarded as the high-affinity receptors for brain-derived neurotrophic factor and neurotrophin-3. Gene transcripts for the high-affinity NGF receptor trkA were found exclusively in non-germ cells. Isolated Leydig cells, peritubular myoid cells and Sertoli cells, but not germ cells, could be identified as potential testicular NGF sources. Non-germ cells respond after incubation for several days with a sharp induction in NGF synthesis, which is accompanied by a loss of phenotypic expression patterns. The fact that p75NGFR mRNA expression was induced in cultured Sertoli cells and peritubular myoid cells suggests an autocrine mode of NGF action in these cells. Induction of NGF synthesis in cultured Leydig cells could be prevented by the glucocorticoid dexamethasone. Results indicate different roles for the individual neurotrophins in distinct testicular compartments and suggest that these neurotrophins might support testicular functions by signalling between individual cell types in an autocrine and paracrine manner.

scholarly journals Expression of beta-nerve growth factor and its receptor in rat seminiferous epithelium: specific function at the onset of meiosis.

1992 ◽  
Vol 117 (3) ◽  
pp. 629-641 ◽  
Author(s):  
M Parvinen ◽  
M Pelto-Huikko ◽  
O Söder ◽  
R Schultz ◽  
A Kaipia ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Nerve Growth Factor ◽  
Growth Factor ◽  
Sertoli Cells ◽  
Seminiferous Epithelium ◽  
Receptor Protein ◽  
Tyrosine Kinase Receptor ◽  
Specific Expression ◽  
Nerve Growth ◽  
Ngf Receptor

beta-Nerve growth factor (NGF) is expressed in spermatogenic cells and has testosterone-downregulated low-affinity receptors on Sertoli cells suggesting a paracrine role in the regulation of spermatogenesis. An analysis of the stage-specific expression of NGF and its low affinity receptor during the cycle of the seminiferous epithelium in the rat revealed NGF mRNA and protein at all stages of the cycle. Tyrosine kinase receptor (trk) mRNA encoding an essential component of the high-affinity NGF receptor was also present at all stages. In contrast, expression of low affinity NGF receptor mRNA was only found in stages VIIcd and VIII of the cycle, the sites of onset of meiosis. The low-affinity NGF receptor protein was present in the plasma membrane of the apical Sertoli cell processes as well as in the basal plasma membrane of these cells at stages VIIcd to XI. NGF was shown to stimulate in vitro DNA synthesis of seminiferous tubule segments with preleptotene spermatocytes at the onset of meiosis while other segments remained nonresponsive. We conclude that NGF is a meiotic growth factor that acts through Sertoli cells.

scholarly journals PC12 cell mutants that possess low- but not high-affinity nerve growth factor receptors neither respond to nor internalize nerve growth factor.

1986 ◽  
Vol 102 (3) ◽  
pp. 830-843 ◽  
Author(s):  
S H Green ◽  
R E Rydel ◽  
J L Connolly ◽  
L A Greene
Keyword(s):  
Nerve Growth Factor ◽  
Growth Factor ◽  
Cell Surface ◽  
Pc12 Cells ◽  
Selection Procedure ◽  
Division Rate ◽  
Nerve Growth ◽  
High Affinity ◽  
Ngf Receptor ◽  
Epidermal Growth

Four mutant PC12 pheochromocytoma cell lines that are nerve growth factor (NGF)-nonresponsive (PC12nnr) have been selected from chemically mutagenized cultures by a double selection procedure: failure both to grow neurites in the presence of NGF and to survive in NGF-supplemented serum-free medium. The PC12nnr cells were deficient in all additional NGF responses surveyed: abatement of cell proliferation, changes in glycoprotein composition, induction of ornithine decarboxylase, rapid changes in protein phosphorylation, and cell surface ruffling. However, PC12nnr cells closely resembled non-NGF-treated PC12 cells in most properties tested: cell size and shape; division rate; protein, phosphoprotein, and glycoprotein composition; and cell surface morphology. All four PC12nnr lines differed from PC12 cells in three ways in addition to failure of NGF response: PC12nnr cells failed to internalize bound NGF by the normal, saturable, high-affinity mechanism present in PC12 cells. The PC12nnr cells bound NGF but entirely, or nearly entirely, at low-affinity sites only, whereas PC12 cells possess both high- and low-affinity NGF binding sites. The responses to dibutyryl cyclic AMP that were tested appeared to be enhanced or altered in the PC12nnr cells compared to PC12 cells. Internalization of, and responses to, epidermal growth factor were normal in the PC12nnr cells ruling out a generalized defect in hormonal binding, uptake, or response mechanisms. These findings are consistent with a causal association between the presence of high-affinity NGF receptors and of NGF responsiveness and internalization. A possible relationship is also suggested between regulation of cAMP responses and regulation of NGF responses or NGF receptor affinity.

CRK protein binds to two guanine nucleotide-releasing proteins for the Ras family and modulates nerve growth factor-induced activation of Ras in PC12 cells

1994 ◽  
Vol 14 (8) ◽  
pp. 5495-5500
Author(s):  
M Matsuda ◽  
Y Hashimoto ◽  
K Muroya ◽  
H Hasegawa ◽  
T Kurata ◽  
...  
Keyword(s):  
Nerve Growth Factor ◽  
Growth Factor ◽  
Pc12 Cells ◽  
Sh2 Domain ◽  
Single Amino Acid ◽  
Guanine Nucleotide ◽  
Nerve Growth ◽  
Tyrosine Residues ◽  
Ngf Receptor ◽  
Ras Family

It has been reported that growth factors activate Ras through a complex of an adaptor type SH2-containing molecule, Grb2, and a Ras guanine nucleotide-releasing protein (GNRP), mSos. We report on the involvement of another adaptor molecule, CRK, in the activation of Ras. Overexpression of wild-type CRK proteins CRK-I and CRK-II enhanced the nerve growth factor (NGF)-induced activation of Ras in PC12 cells, although the basal level of GTP-bound active Ras was not altered. In contrast, mutants with a single amino acid substitution in either the SH2 or SH3 domain of the CRK-I protein inhibited the NGF-induced activation of Ras. Two GNRPs for the Ras family, mSos and C3G, were coimmunoprecipitated with the endogenous Crk proteins in PC12 cells. The association between C3G and the CRK mutants was dependent upon the presence of intact SH3. The SH2 domain of CRK bound to the SHC protein phosphorylated on tyrosine residues by NGF stimulation. The results demonstrate that, in addition to Grb2, CRK participates in signaling from the NGF receptor and that two GNRPs appear to transmit signals from these adaptor molecules to Ras.

trkC, a receptor for neurotrophin-3, is widely expressed in the developing nervous system and in non-neuronal tissues

Development ◽  
1993 ◽  
Vol 118 (2) ◽  
pp. 463-475 ◽  
Author(s):  
L. Tessarollo ◽  
P. Tsoulfas ◽  
D. Martin-Zanca ◽  
D.J. Gilbert ◽  
N.A. Jenkins ◽  
...  
Keyword(s):  
Nerve Growth Factor ◽  
Growth Factor ◽  
Tyrosine Kinases ◽  
Expression Patterns ◽  
Developmental Expression ◽  
Receptor System ◽  
Nerve Growth ◽  
Trk Receptor ◽  
Neurotrophin 3 ◽  
Neuronal Tissues

The Trk family of tyrosine kinases encodes receptors for nerve growth factor-related neurotrophins. Here we present a developmental expression study of trkC, which encodes a receptor for neurotrophin-3 (NT-3). Like the related genes, trk and trkB, trkC is expressed primarily in neural lineages although the pattern is complex and includes non-neuronal cells. Direct comparison with trk and trkB developmental expression patterns permits the following observations. (1) trkC is expressed in novel neural tissues where other Trk genes are silent. (2) Some tissues appear to coexpress trkB and trkC receptors in the embryo and in the adult. (3) trkC expression can be detected in the gastrulating embryo. These data provide insights into the role of Trk-family receptors and nerve growth factor-related neurotrophins during development and suggest that, in addition to regulating neuronal survival and differentiation, the neurotrophin/Trk receptor system may have broader physiological effects. Finally, interspecific mouse backcrosses have been used to map the location of each of the Trk genes on mouse chromosomes. Alignment with available chromosomal maps identify possible linkage between the Trk genes and known neurological mutations.

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