Nerve growth factor mRNA and protein in the testis and epididymis of mouse and rat.

Abstract

In situ hybridization using a-nerve growth factor (NGF) DNA probes was used to demonstrate NGF mRNA in spermatocytes and early spermatids of adult mouse. NGF mRNA-containing cells were also identified in the epithelium of convoluted ducts in mouse corpus epididymidis. Blot-hybridization analysis of RNA prepared from mouse testis and epididymis as well as from rat epididymis confirmed the presence of a 1.3-kilobase (kb) NGF mRNA in these tissues. In the rat testis, however, only a 1.5-kb NGF mRNA was found, corresponding in size to a minor NGF mRNA detected in the rat brain, heart, and epididymis. By using affinity-purified anti-NGF antibodies, NGF-like immunoreactivity was observed in germ cells of rat and mouse testis and in the lumen of epididymis. Extracts of both mouse epididymis and testis stimulated fiber outgrowth in cultured sympathetic ganglia, and the effect was blocked by antibodies to mouse NGF. A two-site enzyme immunoassay showed the presence of 10 and 70 ng of NGF per g of tissue in the mouse testis and epididymis, respectively. Furthermore, RNA blot analysis showed the presence of mRNA for the NGF receptor in mouse testis. These results suggest a nonneurotrophic role for NGF in the male reproductive system, possibly in survival maturation and/or motility of spermatozoa.P-Nerve growth factor (NGF) is a protein essential for the development and maintenance of sensory and sympathetic neurons in the peripheral nervous system (1, 2). Recently RNA blot analysis, enzyme-linked immunoassays, and immunohistoche'mistry have been used to demonstrate NGF mRNA and protein in the mammalian brain (3-6), where NGF has been suggested to support basal forebrain cholinergic neurons (7-10). The levels of NGF mRNA in most peripheral tissues as well as in the brain appear to correlate with their degree of innervation by NGF-sensitive fibers either sympathetic in the periphery or cholinergic in the central nervous system (3-6, 11, 12). In the male mouse submandibular gland, which constitutes an extremely rich source of NGF mRNA and protein, the level of NGF synthesis does not correlate, however, with the innervation by NGF-sensitive fibers (1). Also, relatively high levels of NGF protein have been found in the snake venom gland (1), in guinea pig and rabbit prostate (13-16), and in bull semen and seminal vesicle (17,18). Furthermore, in the mouse testis, NGF-like immunoreactivity was recently shown to be present in germ cells, and a possible role for NGF in sperm maturation or motility was hypothesized (19).In the study reported here, we used a mouse NGF cDNA probe for in situ hybridization and RNA blot analysis to reveal the identity and distribution of cells synthesizing NGF in rodent male genital organs. The presence of NGF protein in the same tissues was studied by immunohistochemistry, immunoassays, and biological tests of activity. Our results show that male mouse germ cells synthesize both NGF mRNA and protein. In addition, NGF mRNA-containing cells were found in the epithelium of convoluted ducts of cor...

Effects of basic fibroblast growth factor and nerve growth factor on lactate production, gamma-glutamyl transpeptidase and aromatase activities in cultured Sertoli cells

“…In situ hybridization studies have shown that NGF mRNA is localized in spermatocytes and round spermatides. Also, NGF protein was detected in these latter cell types by immunohistochemical studies (19,21). On the contrary, in 1996 Seidl et al (22) showed that Leydig, peritubular and Sertoli cells are the source of this peptidic factor.…”

“…NGF is a protein essential for the development and maintenance of sensory and sympathetic neurons of the peripheral nervous system (18). NGF and its receptors have been found not only in the nervous system but also in other organs, including the testis (19)(20)(21)(22). It has been shown that infusion of NGF into adult rat testis in vivo causes an increase in the level of testicular androgen binding protein (ABP) mRNA (23).…”

Effect of NGF on the Motility and Acrosome Reaction of Golden Hamster Spermatozoa In Vitro

“…In addition, a substantial number of observations linking NGF to sperm development have been reported: high levels of NGF mRNA have been discovered in the lower mouse caput epididymis and corpus epididymis, suggesting a role for NGF in sperm maturation [7], testicular and germ cell atrophy following exposure to n-hexane leads to loss of NGF [9] and NGF has been found to be synthesized by spermatocytes and early spermatids [7]. NGF has already been implicated in sperm cell survival either via high affinity receptor TrkA, which is up-regulated by human chronic gonadotropin (hCG) [9] or via low affinity receptor p75, which has been shown to be down-regulated by testosterone [10].…”

“…Despite the central tropic effect of neurotrophins in the nervous system, high levels of NGF have been reported to exist outside the nervous system, particularly in the testis [7,8]. In addition, a substantial number of observations linking NGF to sperm development have been reported: high levels of NGF mRNA have been discovered in the lower mouse caput epididymis and corpus epididymis, suggesting a role for NGF in sperm maturation [7], testicular and germ cell atrophy following exposure to n-hexane leads to loss of NGF [9] and NGF has been found to be synthesized by spermatocytes and early spermatids [7].…”

Localization of Kex2‐like processing endoproteases, furin and PC4, within mouse testis by in situ hybridization

“…In view of the fact that furin cleaves precursors at sites marked by the Arg-X-Lys/ Arg-Arg motif but not at dibasic sites [13,15,26], furin may be involved in maturation of some growth factors, Antisense Sense such as nerve growth factor, transforming growth factor-j?, and inhibin, for the following reasons: first, they are present in testicular cells [18,27]; second, they are produced from precursors through cleavage at Arg-XLys-Arg sites 1131; third, pro-nerve growth factor have been shown to be cleaved by furin [28].…”