title: Response of alpha 2-macroglobulin messenger ribonucleic acid expression to acute inflammation in the testis is different from the response in the liver and brain.
abstract: Recent studies from this laboratory have shown that Sertoli cells derived from 20-day-old rats and cultured in vitro synthesize and secrete a nonspecific protease inhibitor that is structurally and immunologically similar to serum alpha 2-macroglobulin (alpha 2-MG). In contrast to its serum homologue, the testicular alpha 2-MG is not an acute-phase protein in the rat since its protein concentration in the rete-testis fluid does not increase in response to inflammation. In the present study we examined the expression of alpha 2-MG mRNA in the rat testis in comparison to that in the brain and liver following induced inflammation. alpha 2-MG mRNA in the testis did not respond to induced inflammation, whereas its protein concentration in serum and its mRNA level in the brain and liver increased significantly in 20-day-old inflamed rats. In 8-day-old rat testis, where the blood-testis barrier is not yet formed, alpha 2-MG mRNA expression also did not respond to induced inflammation. The mRNA expression of clusterin, another authentic Sertoli cell protein whose secretion appears to be closely related to cell-cell interactions in the seminiferous epithelium, was shown to be unaffected by induced inflammation in the testis, brain, and liver. In view of the unexpected differential expression of alpha 2-MG mRNA to induced inflammation in the testis and liver, we sought to examine whether Sertoli cell alpha 2-MG would respond to FSH and testosterone (T), the major regulators of testicular function. Interestingly, expression of alpha 2-MG and clusterin mRNA in the Sertoli cell was not regulated by FSH, T, or a combination of FSH and T. Since there is an intimate morphological relationship between Sertoli cells and germ cells, we next examined the effect of germ cell-conditioned medium (GCCM) on Sertoli cell alpha 2-MG and clusterin mRNA expression. It was noted that GCCM caused a dose-dependent stimulation of alpha 2-MG and inhibition of clusterin mRNA expression in Sertoli cells, respectively. Therefore, our studies have shown that the regulatory mechanism that modulates the expression of alpha 2-MG mRNA in the rat testis is different from its counterpart in the brain and liver.
authors.affiliation: Population Council, New York, New York 10021.
authors.forename: A H
authors.initials: AH
authors.lastname: Li
authors.forename: I H
authors.initials: IH
authors.lastname: Zwain
authors.forename: C
authors.initials: C
authors.lastname: Pineau
authors.forename: N
authors.initials: N
authors.lastname: Cazzolla
authors.forename: L
authors.initials: L
authors.lastname: Saso
authors.forename: B
authors.initials: B
authors.lastname: Silvestrini
authors.forename: C W
authors.initials: CW
authors.lastname: Bardin
authors.forename: C Y
authors.initials: CY
authors.lastname: Cheng
mesh_terms: D000375:Aging; D000818:Animals; D001921:Brain / Q000378:metabolism; D002478:Cells, Cultured; D051152:Clusterin; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D015870:Gene Expression; D006023:Glycoproteins / Q000235:genetics; D007249:Inflammation / Q000378:metabolism*; D008099:Liver / Q000378:metabolism; D008297:Male; D018832:Molecular Chaperones; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012708:Sertoli Cells / Q000187:drug effects / Q000378:metabolism; D013737:Testis / Q000378:metabolism*; D013739:Testosterone / Q000097:blood / Q000494:pharmacology; D000511:alpha-Macroglobulins / Q000235:genetics*
chemical_list: D051152:Clusterin; D006023:Glycoproteins; D018832:Molecular Chaperones; D012333:RNA, Messenger; D000511:alpha-Macroglobulins; D013739:Testosterone; D005640:Follicle Stimulating Hormone