Biomedical subjects

Valentina Casale

Publications and source records attributed to Valentina Casale.

3 recordsLinked to original sources

PubMed2006

Age-dependent decrease in the ghrelin gene expression in the human adrenal cortex: a real-time PCR study.

Numerous lines of evidence indicate that ghrelin, an endogenous ligand of the growth hormone-secretagogue receptor, is expressed in the human and rat adrenal cortex. In this study, we examined whether ghrelin gene expression undergoes changes in the human adrenal cortex during aging. Semi-quantitative real-time reverse transcription-polymerase chain reaction demonstrated a highly significant negative correlation between ghrelin mRNA and age in adrenal cortex of 27 patients (aged from 33 to 82 years), who underwent unilateral adrenalectomy/nephrectomy for kidney cancer. No significant differences in the level of adrenal ghrelin expression were observed between males and females. Since it has been previously shown that ghrelin exerts a marked growth-stimulating action on cultured adrenocortical cells, we hypothesize that the down-regulation of ghrelin gene transcription in adrenals could be associated with the reported decrease in adrenal DNA synthesis and mitogenic activity during aging.

Adrenal Cortex↗

PubMed2006

In vitro culture on Matrigel favors the long-term maintenance of rat zona glomerulosa-cell differentiated phenotype.

Zona glomerulosa (ZG) cells cultured on plastic within few days dedifferentiate losing their capacity to secrete aldosterone (ALDO) in appreciable amounts. Evidence indicates that extracellular matrix modulates the secretory behavior of adrenocortical cells cultured in vitro. Hence, we compared the morphology and function of rat ZG cells grown on plastic and Matrigel basement membrane matrix (hereinafter Matrigel) for up to 12 days. At day 3, no significant differences were observed between cells cultured on plastic and Matrigel. Starting from day 6, ZG cells cultured on plastic lost their ultrastructural differentiated features (mitochondria with tubular cristae, smooth endoplasmic reticulum cisternae and lipid droplets), exhibiting a fibroblast-like appearance. The mRNA expression of the main steroidogenic enzymes, as evaluated by real-time polymerase chain reaction, the baseline secretion of ALDO and other post-pregnenolone hormones, as evaluated by high pressure liquid chromatography, and the secretory response to ACTH, angiotensin-II and K(+), as evaluated by radioimmunoassay, displayed a time-dependent decrease. Matrigel was found to maintain unchanged both the ultrastructure and the expresion of steroidogenic enzymes of ZG cells until day 12 of culture. Baseline and agonist-stimulated steroid-hormone secretion decreased with the duration of culture on Matrigel, but was always higher than that of ZG cells grown on plastic. Hence, our study clearly indicates that the culture on Matrigel favors the maintenance of rat ZG-cell differentiated phenotype, allowing the conclusion that this technique is suitable for long-term in vitro investigations.

Adrenocorticotropic Hormone↗

PubMed2006

Urotensin-II and UII-receptor expression and function in the rat adrenal cortex.

Urotensin-II (UII) is a potent hypertensive peptide, which has been recognized as an endogenous ligand of the G protein-coupled receptor (GPR)-14, now named UT-R. Real-time PCR demonstrated the expression of UII and UT-R mRNAs in both dispersed and in vitro cultured rat adrenocortical cells. UII concentration-dependently decreased basal, but not ACTH-stimulated, corticosterone secretion from cultured adrenocortical cells, and the effect was abolished by the UT-R antagonist Palosuran. UII did not affect the proliferation rate of cultured cells. Taken together, these findings suggest that UII may be included in the group of peptides (adrenomedullin, atrial natriuretic peptide, neurotensin and beacon), that, acting in an autocrine-paracrine manner, are involved in the inhibitory tuning of adrenocortical secretion.

Adrenal Cortex↗