Search

Objective: Plasma adiponectin (APN) levels are decreased in diabetic patients. Dysfunctional mitochondrial biogenesis is involved in type 2 diabetes (T2DM) pathogenesis, by unclear mechanisms. The present study determined (1) whether myocardial mitochondrial biogenesis was impaired in cardiomyocytes exposed to a high glucose/high fat (HGHF) medium (a T2DM in vitro model), (2) the effects of APN administration upon mitochondrial biogenesis in cardiomyocytes affected by HGHF incubation, and 3) the involved underlying mechanisms., Materials and Methods: Neonatal rat ventricular myocytes (NRVMs) were isolated and incubated in HGHF medium. Mitochondrial function was assessed by ATP content, and fluorescent microscopic analysis of myocardial apoptosis was determined by TUNEL staining and caspase-3 activity., Results: HGHF treatment reduced mitochondrial biogenesis, altered mitochondrial structure, and induced mitochondrial dysfunction in NRVMs. Administration of APN partially rescued these effects. However, siRNA-mediated knockdown of peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1α) significantly blocked the beneficial effects of APN in mitochondria and cardiomyocytes subjected to hypoxia/reoxygenation injury., Conclusions: In the current study, we have provided the direct in vitro evidence that APN partially rescues HGHF-induced impairment of mitochondrial biogenesis and function via PGC-1α-mediated signaling.

Objective: To study the distribution characteristics of adiponectin gene +45 single nucleotide polymorphisms (SNP) in Chinese children, and to determine the role of adiponectin gene +45 polymorphisms in the pathogenesis of childhood obesity., Methods: A total of 147 Chinese obese and 118 healthy children were randomly selected and enrolled to identify adiponectin gene SNP+45 polymorphism by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. Plasma adiponectin levels were determined using ELISA. Waist circumference (WC), waist to hip ratio (WHR), percentage of body fat (%BF), systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting plasma glucose (FPG), serum triglycerides (TG), total cholesterol (TC), high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C), plasma fasting insulin (FINS), and homeostasis model assessment of insulin resistance (HOMA-IR) were measured., Results: The allelic frequency of adiponectin gene SNP+45 in children with obesity and healthy controls were 40.5% and 25.4%, respectively. There were significant differences in the distribution of genotypes and the allelic frequency between the two groups (P<0.05). The plasma adiponectin levels were significantly higher, in contrast, %BF, HOMA-IR, TC and LDL-C levels were significantly lower in obese children with TT genotype than those in obese children with TG or GG genotype., Conclusions: The adiponectin gene SNP+45 polymorphism may be associated with pathogenesis of obesity in children. T→G variance may be associated an increased risk of childhood obesity and result in a decreased level of adiponectin.

Objective: To examine plasma adiponectin (ADPN) and tumor necrosis factor-alpha (TNF-alpha) levels and their correlation in children with obesity in order to investigate the roles of both in the development of childhood obesity., Methods: One hundred and forty-seven children with obesity and 118 normal children who were randomly sampled from five primary schools from the Kaifu District in Changsha were enrolled. Physical shape indexes, including height, weight, waist circumference, hip circumference, and waist to hip ratio (WHR) were measured. Body mass index (BMI) was calculated. Blood pressure was measured. Percentage of body fat (%BF) was measured with dual energy X-ray absorptiometry. Plasmal levels of ADPN and TNF-alpha were detected using ABC-ELISA. Blood concentrations of triglycerides (TG), total cholesterol (TC), high density lipoprotein-cholesterol (HDL-C) and low density lipoprotein-cholesterol (LDL-C) were measured by automatic biochemistry analyzer. Fasting blood glucose level was measured by glucose oxidase method. Fasting blood insulin level was assayed by radioimmunity. Homeostasis model assessment for insulin resistance (HOMA-IR) was performed., Results: Plasma ADPN levels in obese children significantly decreased compared with those in normal children (8.12+/-2.54 mg/L vs 12.22+/-4.68 mg/L; p<0.05), and had a negative correlation with plasma TNF-alpha levels, BMI, WHR and HOMA-IR (p<0.01), and with %BF, fasting insulin, systolic blood pressure and TG (p<0.05). Plasma TNF-alpha levels in obese children significantly increased compared to normal children (171.38+/-34.33 ng/L vs 91.07+/-21.60 ng/L; p<0.01) and positively correlated with BMI, WHR, %BF, fasting insulin, HOMA-IR, TG and systolic blood pressure (p<0.01), and negatively with HDL (p<0.05). Multiple stepwise regression analysis showed that ADPN, BMI and TNF-alpha were main influential factors for %BF (R2=0.926, p<0.01). There was a significant interaction between ADPN and TNF-alpha (p<0.05)., Conclusions: Plasma ADPN levels decreased and plasma TNF-alpha levels increased in children with obesity and both were main influential factors for %BF in children. There was an interaction between ADPN and TNF-alpha, suggesting that they both participate in the development of childhood obesity.