Toll-like receptor 4 (TLR4) and MD-2 recognizes lipid A, the active moiety of microbial lipopolysaccharide (LPS). Little is known about mechanisms for LPS recognition by TLR4-MD-2. Here we show ligand-induced TLR4 oligomerization, homotypic interaction of TLR4, which directly leads to TLR4 signaling. Since TLR4 oligomerization normally occurred in the absence of the cytoplasmic portion of TLR4,...

The role of reactive oxygen and nitrogen species in local and systemic defense reactions is well documented. NPR1 and TGA1 are key redox-controlled regulators of systemic acquired resistance in plants. NPR1 monomers interact with the reduced form of TGA1, which targets the activation sequence-1 (as-1) element of the promoter region of defense proteins. Here, we report the effect of the physiolo...

OBJECTIVE To determine whether S-nitrosylation of connexins (Cxs) modulates gap junction communication between endothelium and smooth muscle. METHODS AND RESULTS Heterocellular communication is essential for endothelium control of smooth muscle constriction; however, the exact mechanism governing this action remains unknown. Cxs and NO have been implicated in regulating heterocellular communi...

Cell wall is the major component of root apoplast which is the main reservoir for iron in roots, while nitric oxide (NO) is involved in regulating the synthesis of cell wall. However, whether such regulation could influence the reutilization of iron stored in root apoplast remains unclear. In this study, we observed that iron deficiency elevated NO level in tomato (Solanum lycopersicum) roots. ...

background: toll-like receptor (tlr)-mediated inflammatory processes are supposed to be involved in pathophysiology of spontaneous abortion and preterm labor. here, we investigated functional responses of human endometrial stromal cells (escs) and whole endometrial cells (wecs) to lipopolysaccharide (lps) and lipoteichoic acid (lta). methods: endometrial tissues were obtained from 15 cycling wo...

Acute renal failure (ARF) induces tubular hyperresponsiveness to TLR4 ligands, culminating in exaggerated renal cytokine/chemokine production. However, the fate of TLR4 protein during acute tubular injury remains unknown. The study sought new insights into this issue. Male CD-1 mice were subjected to 1) unilateral ischemia-reperfusion (I/R), 2) cisplatin (CP) nephrotoxicity, or 3) glycerol-indu...

Previous studies demonstrated that acute alcohol intoxication caused hepatic lipid accumulation. The present study showed that acute alcohol intoxication caused hepatic lipid accumulation in Tlr4-wild-type mice but not in Tlr4-mutant mice. Hepatic sterol-regulatory element binding protein (SREBP)-1, a transcription factor regulating fatty acid and triglyceride (TG) synthesis, was activated in a...

RATIONALE Recent studies demonstrate a role for toll-like receptor 4 (TLR4) in the pathogenesis of pulmonary hypertension (PH); however, the cell types involved in mediating the effects of TLR4 remain unknown. OBJECTIVES The objective of this study was to determine the contribution of TLR4 expressed on nonparenchymal cells to the pathogenesis of PH. METHODS AND RESULTS TLR4 bone marrow chim...