The Mechanism Of Chinese Herbal Prescription FTZ Improving Insulin Sensitivity In Lipodystrophy Mice Via Regulating Adipose Tissue Macrophage Polarization

Objective:1.To observe the metabolic characteristics of aP2-SREBP1 c transgenic lipodystrophy mice with insulin resistance and study the effect of lipoatrophy on adipose tissue macrophages due to lipodystrophy.2.To investigate the change of adipose tissue macrophage polarization induced by lipodystrophy in aP2-SREBP1 c mice under cold stimulation.3.To explore the effect of FTZ on aP2-SREBP1 c lipodystrophy mice with insulin resistance via macrophage polarization of adipose tissue.4.To study the effect of FTZ on improving insulin resistance in aP2-SREBP1 c lipodystrophy mice and its possible mechanism under cold stimulation.Methords:The aP2-SREBP1 c mice were genotyped and randomly grouped according to body weight,GLU,TG and TC,each group was divided into 2 parts.The cold stimulation part was in 4 hours per day in 4? environment and the room temperature part was in 25? environment(25±2?).The changes in body weight were observed weekly,and fasting blood parameters were taken every 2 weeks,and the levels of GLU,TG,TC,HDL-C,and LDL-C were dynamically observed.After 10 weeks of treatment,the mouse fat content was measured using the TD-NMR body composition analyzer.After 11 weeks of treatment,an oral glucose tolerance test(OGTT)was performed.We dissected the mice after 12 weeks of administration,the mitochondrial oxygen consumption test was used to detect the cell respiration rate of brown adipose tissue SVF cells,and the macrophage M1 and M2 polarized phenotypes in subcutaneous fat SVF cells were detected by flow cytometry.Observed by HE staining observed subcutaneous adipose tissue,brown adipose tissue,liver tissue,kidney tissue,pancreatic tissue and other histopathological conditions;blood stained by oil red O to observe the pathological changes of fatty tissue in the liver;liver tissue was observed by PAS glycogen staining The content of glycogen.RT-PCR detected the mRNA expressoion of F4/80,CD11 c,TNF?,IL-4,PI3 K,IL-10,METRNL,PGC1? and other genes related to the polarization of macrophages in subcutaneous adipose tissue and adipose tissue,and the adaptive heat production of adipose tissue.Results:1.The aP2-SREBP1 c lipodystrophy mice has a glycogen-lipid metabolic phenotype.Macrophages in the subcutaneous adipose tissue are polarized to M1-type macrophages,and there is high expression of pro-inflammatory cytokine TNF? in subcutaneous adipose tissue;brown adipose tissue is whitening.2.After a Medium and long-term cold stimulation,the chronic inflammatory state of the subcutaneous adipose tissue of the aP2-SREBP1 c lipodystrophy model mouse is alleviated,which related to the adipose tissue macrophage M2 polarization.And the insulin sensitivity is also improved.3.After 12 weeks of treatment of FTZ,the results showed that FTZ could effectively reduce the plasma concentrations of GLU,TG,TC,LDL-C,NEFA and insulin in mice with lipid metabolic disorder induced by high fat diet.The OGTT showed that FTZ could effectively reduce the AUC value(P<0.05).The results of oil red O staining showed that FTZ could effectively reduce the size and quantity of lipid droplets in liver(P<0.05).GC-MS results showed that FTZ could lead to significant decreases in total fatty acids both liver and plasma.In the meanwhile,the insulin sensitivity of aP2-SREBP1 c lipodystrophy mice was significantly improved.Hepatic lipid metabolism has also been improved.The above experimental results further verify that FTZ has the efficacy of preventing and treating type 2 diabetes,decreasing insulin resistance,and resisting non-alcoholic fatty liver.Its mechanism might be related to the regulation of macrophage polarization in adipose tissue and the promotion of adaptive thermogenesis ability.4.After the treatment of FTZ as well as cold stimulation,it was found that the simultaneous intervention of both will enhance the adaptive thermogenesis ability,reduce the metabolic chronic inflammation,and improve glucose tolerance and reduce insulin resistance in the adipose tissue of aP2-SREBP1 c lipodystrophy mice.Conclusion:1.The aP2-SREBP1 c lipodystrophy mice has dysregulated glucose and lipid metabolism,insulin resistance,and phenotype of M1 polarization in adipose tissue macrophages.2.Cold stimulation can improve the glucose and lipid metabolism and insulin sensibility in aP2-SREBP1 c lipodystrophy mice,and promote the M2 polarization of subcutaneous white adipose tissue macrophages.3.The treatment of FTZ can improve glucose and lipid metabolism and insulin sensibility in aP2-SREBP1 c lipodystrophy mice,and promote the M2 polarization of subcutaneous white adipose tissue macrophage.4.The combination of medium and long-term cold stimulation and FTZ administration can effectively improve the insulin resistance in aP2-SREBP1 c lipodystrophy mice,and the mechanism is related to the promotion of M2 polarization of subcutaneous white adipose tissue macrophages.