Endothelial dysfunction plays a crucial role in the pathophysiology of sepsis. Alterations in endothelial nitric-oxide synthase (eNOS) may contribute to the impaired endothelial function. We investigated whether the regulatory mechanism for eNOS phosphorylation and activation is altered in a rabbit lipopolysaccharide-induced septic model. Following induction of sepsis, a time-dependent marked r...

Arteries from deoxycorticosterone acetate (DOCA)-salt and N(omega)-nitro-L-arginine (L-NNA) hypertensive but not normotensive rats develop spontaneous tone. LY294002 and wortmannin, phosphoinositide 3-kinase (PI3-kinase) inhibitors, eliminate spontaneous tone. We hypothesized that PI3-kinase protein and/or activity was increased in hypertension and contributed to the observed enhanced contracti...

The steroid hormone 1 ,25-dihydroxyvitamin D3 [1 ,25-(OH)2D3] promotes vascular smooth muscle cell (VSMC) growth and calcification, but the precise mechanism by which 1 ,25-(OH)2D3 regulates VSMC migration is unknown. In rat aortic SMCs, we found that 1 ,25-(OH)2D3 (0.1 to 100 nmol/L) induced a dose-dependent increase in VSMC migration. This response required the activation of phosphatidylinosi...

In this study, we investigated the signaling pathways involved in inflammatory production caused by peptidoglycan (PGN), a cell wall component of the gram-positive bacterium, in BV-2 microglia. PGN caused a concentration- and time-dependent increase in inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) mRNA and protein levels. In addition, PGN also induced IL-1 beta, TNF-alpha ...

BACKGROUND Signaling through MEK-->ERK1/2 and PI3 kinases is implicated in many aspects of cell physiology, including the survival of oxidant exposure. Oxidants play a role in numerous physiological and pathophysiological processes, many of which rely on transport in and out of the nucleus. However, how oxidative stress impacts nuclear trafficking is not well defined. METHODOLOGY/PRINCIPAL FI...

We investigated the role of cdc42, a Rho GTPase family member, in insulin-induced glucose transport in 3T3-L1 adipocytes. Microinjection of anti-cdc42 antibody or cdc42 siRNA led to decreased insulin-induced and constitutively active G(q) (CA-G(q); Q209L)-induced GLUT4 translocation. Adenovirus-mediated expression of constitutively active cdc42 (CA-cdc42; V12) stimulated 2-deoxyglucose uptake t...

Translation of terminal oligopyrimidine tract (TOP) mRNAs, which encode multiple components of the protein synthesis machinery, is known to be controlled by mitogenic stimuli. We now show that the ability of cells to progress through the cell cycle is not a prerequisite for this mode of regulation. TOP mRNAs can be translationally activated when PC12 or embryonic stem (ES) cells are induced to ...

The Ptdlns-3-kinase (PI3-K) signaling pathway plays a vital role in cell survival, proliferation, apoptosis and differentiation in normal cells, as well as in diseases such as cancer and diabetes. Quantification of phospho-Akt is a standard way of assessing the activity of the PI3-K signaling pathway in both cells and tumors. This measurement is traditionally performed semiquantitatively using ...

BACKGROUND Glutamine appears to mediate protection against gut injury via multiple pathways. These include fibronectin-integrin, PI3-K/MAPK pathways, and activation of heat shock protein (HSP) response. We hypothesize there may be a relationship between these pathways mediating glutamine's protection in intestinal epithelial-6 cells after heat stress. We assessed whether p38MAPK and PI3-K/Akt s...

We evaluated the role of the G alpha-q (Galphaq) subunit of heterotrimeric G proteins in the insulin signaling pathway leading to GLUT4 translocation. We inhibited endogenous Galphaq function by single cell microinjection of anti-Galphaq/11 antibody or RGS2 protein (a GAP protein for Galphaq), followed by immunostaining to assess GLUT4 translocation in 3T3-L1 adipocytes. Galphaq/11 antibody and...