Changes in VGF and C3aR1 gene expression in human adipose tissue in obesity.

The VGF gene, which has been shown to be metabolically associated with energy balance, glucose homeostasis, insulin secretion process, and biological processes related to overeating, is prominent in relation to obesity. TLQP-21 neuropeptide, derived from the VGF, is considered to promote lipolysis by the beta-adrenergic pathway through targeting the C3aR1 receptor located in the adipocyte membrane. In this study, we aimed to measure the expression levels of the VGF and C3aR1 genes in the adipose tissue of obese subjects and individuals with normal weight determined based on body mass index (BMI), and to reveal the correlation of these levels with obesity. VGF and C3aR1 gene expression levels were measured using Real Time Polymerase Chain Reaction (RT PCR) in the visceral adipose tissue (VAT) samples of 52 obese patients (BMI ≥ 35 kg/m2) and 21 non-obese controls (BMI = 18.5-24.9 kg/m2). The results were statistically analyzed. The VGF expression was lower and the C3aR1 gene expression was higher in obese patients compared to the non-obese control group (p < 0.05). In obese patients, there was a statistically significant positive correlation of 85.6% between VGF and C3aR1, in which when one level increased, the other also increased (p < 0.05, r = 0.856). The findings show that the VGF may be significantly associated with obesity and is very important since it is the first to measure the level of VGF gene expression in human adipose tissue. This research provides new evidence of a link between obesity and VGF/C3aR1 and in the future may help design strategies to combat obesity.

High pO2-activated inhibitor of protein synthesis in rabbit reticulocytes: its relationship to glutathione disulfide-induced inhibitor and to a approximately 23,000-Mr sulfhydryl protein.

The treatment of reticulocyte post-ribosomal supernatant containing ribosome wash with high pO2 or glutathione disulfide resulted in the activation of an inhibitor of protein synthesis of approximately 23,000-Mr as implicated by its elution from Sephadex G-100. This inhibitor could also be directly activated by exposure of the approximately 23,000-Mr fractions of the control eluate to high pO2 or glutathione disulfide. The high pO2-dependent activation of the inhibitor was blocked by the presence of glucose-6-phosphate or cAMP (2 mM). The inhibitor was stable (and activable) during a 5 minute incubation at 80 degrees C. The analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the G-100 (approximately 23,000-Mr) fractions treated with [14C]N-ethylmaleimide revealed the abolishment of the label in a approximately 23,000-Mr protein band in parallel to high pO2-dependent inhibitor activation.

A translational inhibitor activated in rabbit reticulocyte lysates under high pO2.

An inhibitor of protein synthesis was activated under high oxygen partial pressure (pO2) in hemin-supplemented and glutathione disulfide-free lysates from rabbit reticulocytes. This inhibitor shared some common features with other translational inhibitors from rabbit reticulocytes; that is, hemin-controlled repressor, glutathione disulfide-activated inhibitor and high pressure-activated inhibitor. It caused biphasic kinetics of inhibition which could be potentiated by ATP. Its activation was prevented by cAMP or glucose 6-phosphate. The high pO2-inhibitor could be partially purified from post-ribosomal supernatant containing ribosomal salt wash by precipitation between 0-50% (NH4)2SO4-saturation, Sephadex G-100, and DEAE-cellulose chromatography.