Publications

The HIV-1 virion-associated accessory protein Vpr affects both viral replication and cellular transcription, proliferation, and differentiation. We report that Vpr enhances the activity of glucocorticoids in lymphoid and muscle-derived cell lines by interacting directly with the glucocorticoid receptor and general transcription factors, acting as a coactivator. Vpr contains the signature motif LXXLL also present in cellular nuclear receptor coactivators, such as steroid receptor coactivator 1 and p300/CREB-binding protein, which mediates their interaction with the glucocorticoid and other nuclear hormone receptors. A mutant Vpr molecule with disruption of this coactivator signature motif lost its ability to influence transcription of glucocorticoid-responsive genes and became a dominant-negative inhibitor of Vpr, possibly by retaining its general transcription factor–binding activities. The glucocorticoid coactivator activity of Vpr may contribute to increased tissue glucocorticoid sensitivity in the absence of hypercortisolism and to the pathogenesis of AIDS.

Primary aldosteronism (PA) is the most common cause of endocrine hypertension that is diagnosed following a two-step process: an initial screening test, based on the serum aldosterone-to-renin ratio (ARR), followed by a relatively laborious and time-consuming confirmatory test to document autonomous aldosterone (ALD) secretion.The aim of this study is to develop a simple overnight test for the early and definite diagnosis of PA.Totally, 148 hypertensive patients underwent a fludrocortisone-dexamethasone suppression test (FDST) and the new overnight diagnostic test (DCVT) using pharmaceutical RAAS (renin-angiotensin-aldosterone system) blockade with dexamethasone, captopril and valsartan.Of the 148 patients, 45 were diagnosed as having PA and they all normalized their elevated blood pressure (BP) after administration of spironolactone or eplerenone. The remaining 103 patients were considered as having essential hypertension and served as controls. Using ROC analysis, the estimated sensitivity and specificity were 91 and 100%, respectively, for the post-FDST ARR, whereas 98% and 89% and 100% and 82% for the post-DCVT ARR and post-DCVT ALD, respectively, with selected cutoffs of 0.32ng/dL/μU/mL and 3ng/dL respectively. However, considering these cutoffs simultaneously, the estimated sensitivity and specificity were 98 and 100% respectively. Applying these cutoffs, the diagnosis of PA was confirmed in 44 (98%) of the 45 patients who were considered to have the disease.In this study, a highly sensitive and specific, low-cost, rapid, safe, and easy-to-perform diagnostic test (DCVT) for PA is described, which could be utilized on an outpatient basis potentially substituting conventional laborious testing.

After extensive suprasellar operations for hypothalamic tumor removal, some patients develop Cushing-like morbid obesity while they receive replacement doses of glucocorticoids. In this study, we examined the hypothesis that target tissue conversion of inactive 11-ketosteroids to active 11 beta-OH glucocorticoids might explain the obesity of some patients with hypothalamic lesions. Toward this aim, we studied 10 patients with hypothalamic obesity and secondary adrenal insufficiency and 6 control Addisonian patients while they were on glucocorticoid replacement therapy. Pituitary hormone deficiencies were replaced when medically indicated. Twenty-four-hour urine was collected after a single oral dose of 12 mg/m(2) hydrocortisone acetate. The ratios of free and conjugated cortisol (F) to cortisone (E) and their metabolites, [tetrahydrocortisol (THF)+5 alpha THF]/tetrahyrdocortisone (THE), dihydrocortisols/dihydrocortisones, cortols/cortolones, and (F+E)/(THF+THE+5 alpha THF), were considered to represent 11 beta-hydroxysteroid dehydrogenase (HSD) activity. The 11-OH/11-oxo ratios were significantly higher in the urine of patients with hypothalamic obesity. The 11-OH/11-oxo ratios, however, did not correlate with the degree of obesity, yet a significant correlation was found between conjugated F/E and the ratio of visceral fat to sc fat measured by computerized tomography at the umbilical level. The consequence of increased 11 beta-HSD1 activity and the shift of the interconversion toward cortisol may contribute to the effects of the latter in adipose tissue. We propose that deficiency of hypothalamic messengers after surgical injury induces a paracrine/autocrine effect of enhanced glucocorticoid activity due to up-regulated 11 beta-HSD1 activity.

GH insensitivity (GHI) is an autosomal recessive disorder caused by defects in the GH receptor (GHR). In a 17-yr-old female with severe short stature and biochemical features of GHI, sequencing of GHR gene revealed a compound heterozygosity for two novel mutations: C83X and a G deletion at position 1776 (1776del). 1776del is predicted to result in GHR truncation to 581 amino acids with a nonsense sequence of residues 560-581. To clarify the effect of 1776del on GHR function, wild-type GHR, GHR-1776del, and two additional GHR mutants, GHR-L561X (stop codon at site of the 1776del) and GHR-I582X (translation termination in GHR-1776del) were transiently expressed in CHO cells. After incubation with recombinant human GH, GHR-1776del showed lower signal transducer and activator of transcription 5 (STAT5)-mediated transcriptional activation ( approximately 50%, P < 0.05), as well as STAT5 Tyr694 phosphorylation (P < 0.05) compared with wild-type GHR, whereas GHR-L561X and GHR-I582X showed normal STAT5 phosphorylation and transcriptional activity. In contrast, all vectors produced similar effects on STAT3-mediated transcriptional activation. In conclusion, this novel GHR-1776del mutation in a classical GHI patient illustrates an important mechanism of impaired GHR-STAT5 but intact GHR-STAT3 signaling. This effect might result from interference of C-terminal nonsense sequence in mutated GHR with STAT5 docking to upstream tyrosine residues.

Crocus sativus L. has various pharmacological properties, known for over 3600 years. These properties are attributed mainly to biologically active substances, which belong to the terpenoid group and include crocins, picrocrocin and safranal. The aim of the current work was to examine the effects of crocins (CRCs) and their methyl ester derivate dimethylcrocetin (DMCRT) on glioblastoma and rhabdomyosarcoma cell lines, in terms of cytotoxicity and gene expression, implicated in proapoptotic and cell survival pathways. Cell cytotoxicity was assessed with Alamar Blue fluorescence assay after treatment with saffron carotenoids for 24, 48 and 72 h and concentrations ranging from 22.85 to 0.18 mg/mL for CRCs and 11.43 to 0.09 mg/mL for DMCRT. In addition, BAX, BID, BCL2, MYCN, SOD1, and GSTM1 gene expression was studied by qRT-PCR analysis. Both compounds demonstrated cytotoxic effects against glioblastoma and rhabdomyosarcoma cell lines, in a dose- and time-dependent manner. They induced apoptosis, via BAX and BID upregulation, MYCN and BCL-2, SOD1, GSTM1 downregulation. The current research denotes the possible anticancer properties of saffron carotenoids, which are considered safe phytochemicals, already tested in clinical trials for their health promoting properties.

Few population-based, longitudinal studies have examined risk factors for persistent insomnia, and the results are inconsistent. Furthermore, none of these studies have examined the role of polysomnographic (PSG) variables such as sleep duration or sleep apnea on the persistence of insomnia.