Induction of cyclooxygenase (COX)-2 in human vaginal epithelial cells in response to TLR ligands and TNF-α.

Problem: Mucosal inflammation caused by infections of the female lower genital tract is considered to be an important cofactor for HIV transmission. We hypothesize that COX-2, a key inflammation-related enzyme, is involved in these responses and is upregulated by microbial ligands and pro-inflammatory cytokines.

Method Of Study: Human vaginal epithelial cells (VK-2/E6E7) and ectocervical biopsy tissues were stimulated with TLR ligands and the cytokine TNF-α, used as surrogates of vaginal infections, and assessed for COX-2 expression and activity by microarray, real-time RT-PCR, immunoblotting, immunohistochemistry, and ELISA.

Increased COX-2 expression in human vaginal epithelial cells exposed to nonoxynol-9, a vaginal contraceptive microbicide that failed to protect women from HIV-1 infection.

Problem: Despite displaying virucidal activity in vitro, nonoxynol-9 (N-9), a vaginal contraceptive microbicide candidate, failed to reduce the rate of human immunodeficiency virus (HIV) transmission in clinical trials. With frequent use, it even increased the risk of HIV acquisition. Such outcome was postulated to be because of N-9-induced mucosal inflammation, which resulted in recruitment of HIV-target immune cells to the sites of virus entry.

Pioglitazone prevents hypertension and reduces oxidative stress in diet-induced obesity.

The objective of this study was to determine the effect of pioglitazone on blood pressure (BP) and oxidative balance in obese, hypertensive, Sprague-Dawley rats and to identify some of the molecular mechanisms involved. After 12 weeks of a moderately high-fat diet, rats diverged into obesity-prone (OP) and obesity-resistant (OR) groups (n=6 per group). At the end of the diet, peroxisome proliferator activated receptor-gamma (PPARgamma) mRNA expression and activity in the renal cortex and medulla of OP rats were significantly lower compared with that in OR rats.

Effect of salt on hypertension and oxidative stress in a rat model of diet-induced obesity.

High-salt diet is known to induce or aggravate hypertension in animal models of hypertension and in humans. When Sprague-Dawley rats (n = 60) are fed a moderately high-fat diet (32% kcal fat, 0.8% NaCl) for 10 wk, about one-half develop obesity [obesity prone (OP)] and mild hypertension, whereas the other half [obesity resistant (OR)] maintain body weight equivalent to a low-fat control (C) and are normotensive.

Src autophosphorylation is an early event in pressure-mediated signaling pathways in isolated resistance arteries.

Elevated blood pressure is associated with varying degrees of arterial growth and remodeling. The mechanisms by which mechanical stress is converted into cellular alteration have yet to be fully elucidated. Our laboratory has demonstrated that Src tyrosine kinases and the extracellular signal-regulated kinase subtype of the mitogen-activated protein kinase family mediate pressure-induced c-fos expression in rat mesenteric arteries.

Role of angiotensin II and free radicals in blood pressure regulation in a rat model of renal hypertension.

One-kidney, 1-clip rats (1K1C) or uninephrectomized controls were treated with either the superoxide dismutase mimetic tempol (0.5 mmol. kg(-1).

Oxidative stress in a rat model of obesity-induced hypertension.

The mechanisms underlying the development of hypertension in obesity are not yet fully understood. We recently reported the development of hypertension in a rat model of diet-induced obesity. When Sprague-Dawley rats (n=60) are fed a moderately high fat diet (32 kcal% fat) for 10 to 16 weeks, approximately half of them develop obesity (obesity-prone [OP] group) and mild hypertension (158+/-3.

Genistein inhibits pressure-induced expression of c-fos in isolated mesenteric arteries.

We have previously demonstrated that elevating intraluminal pressure from 90 to 140 mm Hg in isolated mesenteric arteries increases the expression of proto-oncogenes. These proto-oncogenes encode nuclear transcription factors that regulate the expression of target genes during various stages of the cell cycle. Thus, pressure-induced proto-oncogene expression may represent a mechanism by which pressure can induce growth and/or proliferation of vascular smooth muscle.