Repeated immobilization stress disturbed steroidogenic machinery and stimulated the expression of cAMP signaling elements and adrenergic receptors in Leydig cells

Abstract

Stojkov NJ, Janjic MM, Bjelic MM, Mihajlovic AI, Kostic TS, Andric SA. Repeated immobilization stress disturbed steroidogenic machinery and stimulated the expression of cAMP signaling elements and adrenergic receptors in Leydig cells. Am J Physiol Endocrinol Metab 302: E1239 -E1251, 2012. First published February 28, 2012 doi:10.1152/ajpendo.00554.2011.-This study was designed to evaluate the effect of acute (2 h daily) and repeated (2 h daily for 2 or 10 consecutive days) immobilization stress (IMO) on: 1) the steroidogenic machinery homeostasis; 2) cAMP signaling; and the expression of receptors for main markers of 3) adrenergic and 4) glucocorticoid signaling in Leydig cells of adult rats. The results showed that acute IMO inhibited steroidogenic machinery in Leydig cells by downregulation of Scarb1 (scavenger receptor class B), Cyp11a1 (cholesterol side-chain cleavage enzyme), Cyp17a1 (17␣-hydroxylase/17,20 lyase), and Hsd17b3 (17␤-hydroxysteroid dehydrogenase) expression. In addition to acute IMO effects, repeated IMO increased transcription of Star (steroidogenic acute regulatory protein) and Arr19 (androgen receptor corepressor 19 kDa) in Leydig cells. In the same cells, the transcription of adenylyl cyclases (Adcy7, Adcy9, Adcy10) and cAMPspecific phosphodiesterases (Pde4a, Pde4b, Pde4d, Pde7a, Pde8a) was stimulated, whereas the expression of the genes encoding protein kinase A subunits were unaffected. Ten times repeated IMO increased the levels of all adrenergic receptors and ␤-adrenergic receptor kinase (Adrbk1) in Leydig cells. The transcription analysis was supported by cAMP/testosterone production. In this signaling scenario, partial recovery of testosterone production in medium/content was detected. The physiological significance of the present results was proven by ex vivo application of epinephrine, which increased cAMP/testosterone production by Leydig cells from control rats in greater fashion than from stressed. IMO did not affect the expression of transcripts for Crhr1/Crhr2 (corticotropin releasing hormone receptors), Acthr (adrenocorticotropin releasing hormone receptor), Gr (glucocorticoid receptor), and Hsd11b1 [hydroxysteroid (11-␤) dehydrogenase 1], while all types of IMO stimulated the expression of Hsd11b2, the unidirectional oxidase with high affinity to inactivate glucocorticoids. Thus, presented data provide new molecular/transcriptional base for "fight/adaptation" of Leydig cells and new insights into the role of cAMP, epinephrine, and glucocorticoid signaling in recovery of stress-impaired Leydig cell steroidogenesis.

Orally applied doxazosin disturbed testosterone homeostasis and changed the transcriptional profile of steroidogenic machinery, cAMP/cGMP signalling and adrenergic receptors in Leydig cells of adult rats

“…After evaporation of diethyl ether dry pellets were resuspended for determination of androgen content (Qamar et al, 2010;Janjic et al, 2012;Stojkov et al, 2012).…”

Autocrine regulation of ecdysone synthesis by β3-octopamine receptor in the prothoracic gland is essential for Drosophila metamorphosis

“…Another example is the Leydig cells of the mammalian testes, in which the steroid hormone testosterone is produced mainly in response to pituitary gonadotropin. However, catecholamine signaling through β-adrenergic receptors, the orthologs of Octβ3R, also promotes the production of testosterone from cultured fetal Leydig cells (30,31), which may be the site of catecholamine synthesis in the fetal and mature human testes (32). Thus, monoamines may play a conserved role in modulating and/or stimulating steroid hormone production during physiological and developmental transitions.…”

The opposite roles of glucocorticoid and α1-adrenergic receptors in stress triggered apoptosis of rat Leydig cells

“…We recently showed inhibition of basal adenylyl cyclase activity in IMO rats coupled with sustained upregulation of mRNA expression for several adenylyl cyclase and phosphodiesterase subtypes. Our study also revealed the lack of strong correlation between cAMP and androgen levels in Leydig cells stimulated with epinephrine, suggesting that other factor(s) negatively influence(s) androgen production in vivo in stressed animals (52).…”

“…More recently, it has also been reported that stress and glucocorticoids rapidly increase ␣ 1d -ADR mRNA in the rat brain (8). Repeated stress also increased transcripts for all ADRs expressed in Leydig cells (52), and catecholamines stimulated androgen production in rat (2), golden hamster (44), and Siberian hamster (43) cells. Because it is well known that ADRs play an important antiapoptotic role in breast cancer cells (28), human umbilical vascular endothelial cells (39), and cardiac myocytes (54), we speculated that this signaling pathway may also contribute to the control of apoptotic and/or antiapoptotic signaling and androgenesis in stressed animals.…”

“…The CORT-induced decline in steroidogenic capacity could reflect inhibition of the expression (48) and activity (47) of T-biosynthetic enzymes. Repetitive immobilization stress (IMO)-induced elevation in endogenous CORT levels is also accompanied by changes in the expression of several steroidogenic enzyme RNAs (52). Exogenous glucocorticoids also increase apoptotic events in numerous cell types (32), including Leydig cells (20), which raised the possibility that a decrease in the total number of Leydig cells could contribute to or accounts for LH-independent decline in circulating T levels in stressed animals.…”