Influence of high-fat diet in paternal C57BL/6 mice on liver fat deposition in offspring / 中华肝脏病杂志

Objective@#To investigate the influence of high-fat diet (HFD) in paternal C57BL/6 mice on HFD-induced liver fat deposition in male offspring, as well as transgenerational inheritance caused by paternal HFD and related mechanisms.@*Methods@#A total of 20 male C57BL/6 mice aged 3 weeks (F0) were randomly divided into normal control group (C, 10 mice) and HFD group (HF, 10 mice). After 12 weeks of HFD intervention, the male mice in the HFD group mated with female ones treated with normal diet and pups were obtained. Male pups (F1) were selected as study subjects. According to the intervention for F0 mice, male F1 mice were divided into control male offspring group (CM, 8 mice) and HFD male offspring group (HFM, 9 mice). All these mice were given normal diet after weaning until 4 weeks old, followed by HFD for 4 weeks. The body length and body weight were measured and recorded every week. Oil red O staining was used to observe fat deposition in the liver. Western blot and real-time PCR were used to measure the expression of related proteins and genes involved in the de novo synthesis and aerobic oxidation of fatty acid, mitochondriogenesis, and autophagy.@*Results@#After 4 weeks of HFD intervention, the HFM group had a significantly higher body weight than the CM group (P < 0.05); the oil red O staining showed that compared with the CM group, the HFM had a significant increase in liver fat deposition and a significantly higher integral absorbance value in the oil red O staining-positive area (384 360±57 600 vs 236 754±12 607, P < 0.01). For related factors involved in the de novo synthesis of fatty acid in the liver, compared with the CM group, the HFM group had significant increases in the expression of sterol regulatory element-binding protein-1 and fatty acid synthase (P < 0.05); for related factors involved in the mitochondrial biosynthesis in the liver, the HFM group had significant reductions in the relative expression of peroxisome proliferator-activated receptor-γ coactivator-1α, nuclear respiratory factor 1, and mitochondrial transcription factor A compared with the CM group (P < 0.05). For autophagy-related factors in the liver in the F1 mice, compared with the CM group, the HFM group had a significant reduction in microtubule-associated protein I light chain 3 (LC3-II/I) (P < 0.05) and a significant increase in P62 (P < 0.05), suggesting a reduced autophagy function in the liver.@*Conclusion@#HFD intervention for paternal C57BL/6 mice can increase HFD-induced liver fat deposition in male offspring, which may be related to the increased de novo synthesis of fatty acid and reduced mitochondriogenesis and autophagy function in the liver.

The effect of mTOR/S6K1 signaling pathway on the development of high fat diet-induced mouse insulin resistance / 中国糖尿病杂志

Objective To investigate the effects of mTOR/S6K1 signaling pathway on the development of insulin resistantce. Methods 20 male C57BL/6 mice were divided into normal diet group (NC) and high fat diet group (HF).HF mice were fed with high fat diet for 14 weeks and insulin resistance was confirmed in all mice. We observed the morphology of pancreatic islet by HE staining. Serum insulin concentration was also evaluated by ELISA. Northern blot, Western blot and immunofluorescence were performed to detect mTOR and S6K1 mRNA and protein expression in skeletal muscle. Results As compared with NC group,HF group showed that the body weight and fasting serum insulin level were increased by 21.99%(P＜0.05) and 181.82%(P＜0.01) respectively;the area of pancreatic islet was significantly increased;glucose tolerance was impaired;expressions of mTOR mRNA (125.61±10.43 vs 100.00, P＜0.05) and protein (137.41±7.86 vs 100.00, P＜0.01) were significantly increased. And we also found an significant increase in total S6K1 mRNA (154.98±16.26 vs 100.00, P＜0.01) and protein (137.36±3.08 vs 100.00,P＜0.01) as well as pS6K1 protein (390.15±69.62 vs 50.59±16.65,P＜0.01)expression in HF group as compared with NC group.Conclusions mTOR/S6K1 signaling pathway plays an important role in the development of higt fat diet induced insulin resistance.

Factors accounting for different response of pulmonary and cerebral vessels to hypoxia / 中国病理生理杂志

Roles of sympathicus, sensory neuropeptides (SNP), metabolites of cyclooxygenase, metabolites of lipoxygenase, endothelium derived relaxing factor (EDRF), reactive oxygen (ROS) and potassium channels (PC) in the hypoxic pulmonary vasoconstriction (HPV) and hypoxic cerebral vasodilation (HCVD) were studied in intact rats, rabbits and dogs. Results were as follows: during hypoxia, the excitation of sympathicus results in a constriction of both pulmonary and cerebral vessels; SNP, EDRF and the opening of 4-AP sensitive PC caused the dilation of both of them; metabolites of lipoxygenase mediated HPV and HCVD, whereas metabolites of cyclooxygenase were their modulators; hypoxia induced blockade of the ATP sensitive PC mediated HPV, but had no effect on HCVD; reduction of O_2~+ in the lung might potentiate HPV, but had no effect on HCVD. It is suggested that the alteration of lipoxygenase metabolites, ROS and ATP sensitive PC are factors accounting for the difference in response of pulmonary and cerebral vassels to hypoxia.

Effects of histamine and hypoxia on eNOS gene expression in cultured porcine pulmonary and aorta endothelial cells / 中国病理生理杂志

AIM: To investigate the effect of histamine and hypoxia on the expression of eNOS mRNA and protein in cultured porcine pulmonary artery and aorta endothelial cells. METHODS: Semi-quantitative RT-PCR and immuno-cytochemistry were used. RESULTS: (1) Histamine increased eNOS mRNA expression in a dose-and time dependent manner. For pulmonary endothelial cells, the effect reached peak when exposed to 10 -5 mol/L histamine in 24 h. eNOS mRNA level was increased to 178 2%?7 7% ( P

Effects of hypoxia on endothelial nitric oxide synthase expression in cerebral artery endothelial cells / 中国病理生理杂志

AIM: To investigate the molecular mechanism by which hypoxia affect the endothelial nitric oxide synthase (eNOS) expression in cerebral artery endothelial cells (CAECs). METHODS: Primary cultured porcine CAECs were exposed to hypoxia for 2 h, 6 h, 12 h, 24 h and 48 h. The eNOS mRNA level was determined by RT-PCR. The level of eNOS protein was detected by Western blotting. After specific PKC inhibitors BIM Ⅰ(1 ?mol/L) and G6983 (1 ?mol/L) were added, CAECs were exposed to hypoxia for 24 h. The effect of hypoxia on eNOS mRNA stability was analyzed after actinomycin D was added. RESULTS: After exposure to hypoxia for 2 h, the levels of eNOS mRNA and protein in CAECs were increased. The levels of eNOS mRNA and protein reached peak after 12 h of hypoxia (about 2 5 fold and 2 0 fold, respectively, compared to control), and remained at higher level even after 48 h of hypoxia. Moreover, hypoxia did not change the stability of eNOS mRNA. The specific PKC inhibitors BIM Ⅰ and G6983 attenuated significantly the effects of hypoxia on eNOS gene expression. CONCLUSION: These results suggest that hypoxia may enhance the expression of eNOS gene in CAECs through PKC signaling pathway, which might be one of the mechanisms of cerebral artery dilation and neuroprotection during cerebral hypoxia.