Overexpression of angiopoietin-like protein 4 alters mitochondria activities and modulates methionine metabolic cycle in the liver tissues of db/db diabetic mice.

Angiopoietin-like protein 4 (ANGPTL4) is a circulating protein predominantly produced from fat tissue and liver. Recent data from others and our laboratory have demonstrated this protein to be an important player in energy metabolism and insulin sensitivity. However, the molecular mechanisms underlying its metabolic actions remain elusive.

Adiponectin modulates the glycogen synthase kinase-3beta/beta-catenin signaling pathway and attenuates mammary tumorigenesis of MDA-MB-231 cells in nude mice.

Adiponectin is an adipokine that has pleiotropic beneficial roles in systemic insulin resistance and inflammation. Several recent clinical studies suggest that low serum levels of adiponectin are associated with increased risks of breast cancer. Here, we investigated the direct effects of adiponectin on breast cancer development in vitro and in vivo.

Carbohydrate-labeled fluorescent microparticles and their binding to lectins.

The preparation of micrometer-sized, cross-linked poly(p-phenyleneethynylene) (PPE) beads to which simple monosaccharides are attached is reported. Mannose, glucose, and galactose derivatives have been synthesized. The fluorescence properties, size distribution, and morphology of these microparticles have been elucidated through fluorimetry, fluorescence confocal microscopy, and scanning electron microscopy.

Post-translational modifications of the four conserved lysine residues within the collagenous domain of adiponectin are required for the formation of its high molecular weight oligomeric complex.

Adiponectin is a multifunctional adipokine that circulates as several oligomeric complexes in the blood stream. However, the molecular basis that regulates the production of the adiponectin oligomers remains largely elusive. We have shown previously that several conserved lysine residues (positions 68, 71, 80, and 104) within the collagenous domain of adiponectin are modified by hydroxylation and glycosylation (Wang, Y.

Hypoxia dysregulates the production of adiponectin and plasminogen activator inhibitor-1 independent of reactive oxygen species in adipocytes.

Low plasma levels of adiponectin (hypoadiponectinemia) and elevated circulating concentrations of plasminogen activator inhibitor (PAI)-1 are causally associated with obesity-related insulin resistance and cardiovascular disease. However, the mechanism that mediates the aberrant production of these two adipokines in obesity remains poorly understood. In this study, we investigated the effects of hypoxia and reactive oxygen species (ROS) on production of adiponectin and PAI-1 in 3T3-L1 adipocytes.

Angiopoietin-like protein 4 decreases blood glucose and improves glucose tolerance but induces hyperlipidemia and hepatic steatosis in mice.

Angiopoietin-like protein 4 (ANGPTL4) is a circulating protein predominantly expressed in adipose tissue and liver. Several recent studies demonstrated that ANGPTL4 is the target gene of peroxisome proliferation activators, the agonists of which are widely used as the antidiabetic and lipid-lowering drugs. Here we provide evidence that ANGPTL4 is a blood-borne hormone directly involved in regulating glucose homeostasis, lipid metabolism, and insulin sensitivity.

Testosterone selectively reduces the high molecular weight form of adiponectin by inhibiting its secretion from adipocytes.

The antidiabetic hormone adiponectin circulates in blood as several oligomeric complexes, and the ratios between them are critical in determining insulin sensitivity. In this study we investigated the role of testosterone in regulating the oligomeric complex distribution of adiponectin. Gel filtration analysis revealed that circulating adiponectin existed as the forms of high molecular weight (HMW), middle molecular weight, and low molecular weight complexes in both human and mice.

Glycoxidized low-density lipoprotein regulates the expression of scavenger receptors in THP-1 macrophages.

Low-density lipoprotein (LDL) in patients with diabetes is subject to modification by both oxidation and glycation. In contrast to oxidized LDL, the biological effects of glycoxidized LDL have not been well characterised. In this study, the effects of oxidized, glycated, glycoxidized and oxidized LDL on scavenger receptor gene expressions, and the induction of oxidized LDL uptake and cholesteryl ester accumulation in THP-1 macrophages were compared.