Biomedical subjects

Marcin Rucinski

Publications and source records attributed to Marcin Rucinski.

21 records · Page 2Linked to original sources

PubMed2004

Beacon[47-73] inhibits glucocorticoid secretion and growth of cultured rat and human adrenocortical cells.

Evidence has been recently provided that beacon, an ubiquitin-like protein overexpressed in the hypothalamus of Israeli sand rat, is also expressed in several endocrine glands of the Wistar rat, including adrenal cortex. Moreover, it has been shown that the in vivo administration of beacon[47-73] (hereinafter, beacon) evokes within 60 min a marked decrease in the plasma concentrations of ACTH and corticosterone. Hence, we have investigated the effect of beacon (4x10(-9) or 4x10(-7) M) on the secretion and growth of cultured rat and human zona fasciculata/reticularis (ZF/R) cells. Reverse transcription-polymerase chain reaction detected beacon mRNA in all human adrenal cortexes examined. A 3-h exposure to beacon was ineffective, but prolonged (24 and 96 h) exposures significantly lowered basal corticosterone and cortisol secretion from cultured rat and human ZF/R cells, respectively. Moreover, beacon (4x10(-7) M) counteracted the secretagogue action of 10(-8) M ACTH on cultured cells. The 96-h exposure to beacon concentration-dependently decreased basal proliferation rate of cultured cells, without inducing significant changes in the number of apoptotic and necrotic cells. Beacon (4x10(-7) M) significantly inhibited the proliferogenic effect of 10(-8) M adrenomedullin. In light of the involvement of ubiquitin-like proteins in the control of cell cycle and protein sorting and degradation, the hypothesis is advanced that the inhibitory effect of beacon on the secretion and growth of cultured rat ZF/R cells may be connected to its stimulating effect on proteolysis of steroidogenic enzymes and proteins involved in cell replication.

Adrenal Cortex↗

PubMed2004

Effects of neuropeptides B and W on the secretion and growth of rat adrenocortical cells.

Neuropeptide-B (NPB) and neuropeptide-W (NPW) are recently discovered endogenous ligands of the GPR7- and GPR8-receptors (R), which in humans are expressed in the hypothalamus and probably involved in the regulation of energy homeostasis and neuroendocrine axes. GPR8-Rs are absent in rodents, where the GPR8-like-R has been described. Reverse transcription-polymerase chain reaction detected the expression of NPB, NPW, GPR7-R and GPR8-like-R mRNAs in rat adrenocortical cells (both freshly-dispersed and 4-day-cultured cells). NPB did not acutely (60-min exposure) alter basal aldosterone secretion from freshly dispersed zona glomerulosa cells, while NPW raised it. Both NPB and NPW enhanced ACTH-stimulated aldosterone secretion and did not affect either basal or ACTH-stimulated corticosterone production by dispersed zona fasciculata/reticularis (ZF/R) cells. The prolonged (4-day) exposure to NPW, but not NPB, raised corticosterone secretion from cultured ZF/R cells, and both neuropeptides increased the proliferation rate of cultured cells. Taken together, our findings indicate that NPB and NPW affect rat adrenocortical function, so they may be included in that large family of peptides involved in the autocrine-paracrine stimulation of secretion and growth of adrenal cortex.

Adrenal Cortex↗

PubMed2004

Effects of leptin and leptin fragments on corticosterone secretion and growth of cultured rat adrenocortical cells.

Compelling evidence indicates that leptin, acting via specific receptors (Ob-Ra and Ob-Rb) modulates adrenocortical-cell secretion. However, the results are controversial, inasmuch as either secretagogue or antisecretagogue effects have been reported. Hence, we decided to study the effects of a 96-h incubation with leptin and leptin fragments 116-130, 150-167, 138-167, 93-105, 22-56 and 26-39 (10(-8) and 10(-6) M) on the secretion and growth of cultured rat adrenocortical cells. Reverse transcription-polymerase chain reaction showed that control cultures expressed both Ob-Ra and Ob-Rb isoforms. As expected, ACTH (10(-8) M) raised corticosterone secretion and lowered proliferation rate of cultured cells. Native leptin elicited ACTH-like effects, while fragment 116-130 was ineffective. Leptin fragments 150-167 and 26-39 stimulated corticosterone production, and fragments 138-167 and 22-56 inhibited it. Fragment 93-105 exerted a dose-dependent biphasic effect on corticosterone secretion (i.e. stimulation and inhibition at the concentration of 10(-8) and 10(-6) M, respectively). Leptin fragment 26-39 enhanced proliferation of cultured cells, while fragments 138-167 and 22-56 were ineffective. Fragments 150-167 and 93-105 displayed proliferogenic and antiproliferogenic effects at the concentration of 10(-8) and 10(-6) M, respectively. Taken together, these findings allows us to conclude that native leptin and its fragments interact differently with Ob-Rs or interact with different Ob-R isoforms, thereby variously modulating secretion and growth of cultured rat adrenocortical cells.

Adrenal Cortex↗