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The Mechanism of Sertoli‐Germ Cell Interaction a
Author(s) -
WELSH M. J.,
IRELAND M.,
METTS J.,
TREINEN K.,
PITTENGER G.
Publication year - 1987
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1111/j.1749-6632.1987.tb25056.x
Subject(s) - welsh , medical school , anatomy , medicine , biology , medical education , history , archaeology
It has long been hypothesized that Sertoli cell (SC) function is affected by the neighboring germ cells (GC). Using two-dimensional gel electrophoresis followed by autoradiography of the gels (2-D autoradiography), we observe that GC or GCconditioned medium (GC-medium) causes rapid, dose-dependent, cell-specific changes in 3zP incorporation into proteins of cultured SC. Our results indicate that GC interact with SC by way of the phosphatidylinositol (PI) pathway. For these studies, SC were isolated from young rats and were cultured for three days.' SC cultures were completely free of GC. SC were incubated with 32P for 45 min (32P equilibrates with SC ATP in 20 min). After various short-term treatments, SC proteins were prepared and subjected to 2-D autoradiography.' Several proteins showed increased 32P labeling after dibutyryl cyclic AMP (db CAMP) treatment and were also affected by FSH treatment.'s2 These proteins may be substrates for CAMP-dependent protein kinase (FIG. 1). Treating SC with ionophore A23187 increased 3zP labeling of a M , 26K, PI 5.6 protein (p26), but only if calcium was present in the medium. p26 may be a substrate for calcium/ calmodulin-dependent protein kinase (FIG. 2). Treating SC with ionophore plus 12-0-tetradecanoylphorbol13-acetate (TPA) caused increased phosphorylation of a M, 14K, PI 4.9 protein (p14). p14 may be a substrate for calcium/phospholipid-dependent protein kinase (FIG. 2). Neither p26 nor p14 was affected by db CAMP. p26 and p14 also showed increased 32P labeling after treatment with GC or GC medium3 (FIG. 2). After one min exposure to GC, labeling of p26 doubled, and by 5 min labeling increased 5-fold. The response was dose-dependent. p26 seems to be developmentally expressed in SC; it was observed in SC from 18-day-old or older rats, but was not evident in SC from 14-day-old rats. A GC effect on a p26 in the Sertoli cell-derived TR-ST cell line was seen. No GC effect was observed in Chinese hamster ovary (CHO) cells, and both GC and CHO cells lacked p26. Increased labeling in response to GC or GC medium was also observed in p14. p14 was present in SC from all ages of rats examined and in GC, but a protein with identical 2-D gel mobility was lacking in TR-ST or CHO cells. Current studies in our laboratory include characterization of the GC factor that affects SC, purification of p14 and p26, and elucidation of the PI metabolic pathway in SC. Our results support two hypotheses: Sertoli cells and germ cells interact by way of the PI pathway, and Sertoli cells have multiple response pathways. Some stimuli may activate one pathway whereas other stimuli may affect distinctly different events.