[Effect of Gegen Qinlian Decoction on methylation and expression of Scd1gene in adipose tissue of insulin resistant rats and correlations between methylation and physiological and biochemical parameters].

This study aimed to explore the effect of Gegen Qinlian Decoction(GQD) on the methylation and mRNA expression level of stearoyl CoA desaturase(SCD) gene in the adipose tissue of rats with insulin resistance(IR) induced by high-fat diet as well as the correlations between methylation and physiological and biochemical indicators. The animals were divided into seven groups, namely, blank control(C) group, IR model group, low-(1.65 g·kg~(-1)), medium-(4.95 g·kg~(-1)), and high(14.85 g·kg~(-1))-dose GQD(GQDL, GQDM, and GQDH) groups, rosiglitazone(RGN, 5 mg·kg~(-1)) group, and simvastatin(SVT, 10 mg·kg~(-1)) group. The rat epididymal adipose tissue was collected for detecting all the cytosine methylation levels in two fragments of Scd1 gene by bisulfite sequencing PCR(BSP). Scd1-1 was located in CG shores and Scd1-2 in CG islands, including the transcriptional start site(TSS). The Scd1 mRNA level was determined by quantitative real-time PCR(q-PCR). Spearman correlation coefficient was used to analyze the correlations between amplified fragment C methylation and physiological and biochemical indicators. The results showed that GQDM remarkably reversed the elevated CG7 methylation in the TSS upstream region of Scd1-2 triggered by high-fat diet. GQDL significantly reversed the lowered total CG methylation in the downstream region of Scd1-2 induced by the high-fat diet. GQD did not significantly improve the decreased Scd1 mRNA expression caused by high-fat diet. Changes in methylation of the total CG, CG5 and CT11 of Scd1-1 in CG shores exhibited significant negative correlations with the serum triglyceride(TG) but positive correlation with the Scd1 mRNA level. The methylation of several C sites in the TSS upstream region of Scd1-2 was positively correlated with physiological and biochemical parameters. The methylation of several CG sites in the TSS downstream region of Scd1-2 was negatively associated with physiological and biochemical parameters. Besides, the methylation of several CH sites in the downstream fragment was positively correlated with physiological and biochemical parameters. All these have demonstrated that GQD may exert the therapeutic effect by regulating the methylation of CG7 in the TSS upstream region and total CG site in the TSS downstream region of Scd1 gene. The methylation of total CG, CG5 and CT11 sites in CG shores of Scd1 gene may be important targets for regulating Scd1 mRNA level and affecting serum TG.

[Preliminary study on effect of Gegen Qinlian Decoction on enzyme activity, gene expression and methylation level of FASN in adipose tissue of rats with insulin resistance].

To investigate the effect of Gegen Qinlian Decoction(GQD) on enzyme activity, gene expression and methylation level of fatty acid synthase(FASN) in adipose tissue from rats with insulin resistance induced by high-fat diet. The 60% fat-powered high-fat diet was continuously given to male SD rats to induce the insulin resistance model. Then, they were divided into five groups randomly and administrated by gavage every day for 16 weeks with following drugs respectively: 10 mL·kg~(-1)water for control group(C) and insulin resistance model control group(IR), 1.65 g·kg~(-1)GQD per day for low-dose group(GQDL), 4.95 g·kg~(-1)GQD per day for medium-dose group(GQDM), 14.85 g·kg~(-1)GQD per day for high-dose group(GQDH), and 5 mg·kg~(-1) rosiglitazone per day for rosiglitazone group(RGN). Epididymal adipose tissue was taken to determine enzyme activity of FASN by colorimetric method, mRNA expression level of Fasn by quantitative Real-time PCR(Q-PCR) and CpGs methylation level between +313 and +582 by bisulfite sequencing PCR(BSP). These results showed that Fasn expression was significantly lowered in IR model rats compared with the control rats(P<0.01). Enzymatic activity and CpGs methylation level of Fasn in IR group showed downward trends. Low and medium-dose GQD can increase enzyme activity of FASN(P<0.05). Moreover, low-dose GQD increased the total CpGs methylation level of Fasn fragment between +313 and +582 in insulin resistance rats(P<0.05). For GQDM group, the methylation frequency of CpGs at positions +506 and +508(P<0.01) as well as the methylation frequency of CpGs on the binding sites of transcription factorzinc finger protein 161(P<0.05) were significantly increased. The methylation frequency of CpG at +442 position was positively correlated with Fasn expression(P<0.01, r=0.735), and methylation frequencies of CpGs at +345 and +366 positions were positively associated to enzyme activity of FASN respectively(P<0.05, r=0.479; P<0.01, r=0.640). In conclusion, GQD can reverse enzyme activity of FASN and methylation level of Fasn in adipose tissue of insulin resistant rats, and CpG sites at positions +506 and +508 may be the targets of GQD. The methylation level of CpGs at + 345 and + 366 sites were possibly related to FASN activity, while methylation of CpG at + 442 site may be closely correlated with mRNA level of Fasn. In addition, GQD did not significantly change mRNA expression level of Fasn, but effectively reversed enzymatic activity, suggesting that GQD may regulate the post transcriptional expression of Fasn.

[DNA methylation in adipose tissue and the development of diabetes and obesity].

Diabetes and obesity are complicated metabolic diseases which frequently occur together and are affected by environmental, hereditary and metabolic factors. Adipose tissue is involved in various physiological and pathological processes and plays an essential role as an endocrine organ which regulates the metabolic balance of the body. DNA methylation of some genes in adipose tissue may have an impact on its function. A growing body of evidence suggests that changes in DNA methylation may alter gene expression and lead to the development of diabetes and obesity in which adipose tissue function is imbalanced. This review discusses recent advances in alterations of DNA methylation in different types of adipose tissue in individuals with diabetes and obesity. This evidence may lead to a greater understanding of the pathogenesis of these diseases and lead to potential therapeutic interventions and management strategies for diabetes and obesity.

[Effect of Ligustri Lucidi Fructus on hepatic COX activity in normal rats and preliminary investigation of its DNA methylation mechanism].

The study aims to investigate the effect of Ligustri Lucidi Fructus on cytochrome c oxidase(COX) activity in rat hepatic tissues and explore its possible mechanism of DNA methylation. Male SD rats received aqueous extract of Ligustri Lucidi Fructus (2.0，6.0 g•kg⁻¹) by intragastric administration for 30 d. After the rats were sacrificed, hepatic tissues of rats were taken to detect COX activity, protein concentration of COX4I1, TET1 and DNMT3A protein levels, mRNA expression levels of Cox4i1, Dnmt3a and Tet1, and determine the DNA methylation frequency of Cox4i1.Results showed that both low and high doses of Ligustri Lucidi Fructus could significantly increase COX activity and concentration of COX4I1(P<0.05), with a decreasing tendency of both TET1 protein and DNMT3a protein expression； however, mRNA expression levels of Cox4i1, Dnmt3a and Tet1 were not significantly changed by Ligustri Lucidi Fructus. In addition, DNA methylation frequency of Cox4i1 in high dose group showed a declining tendency as compared with the blank control group, but without significant difference.These results indicated that Ligustri Lucidi Fructus had promotive effect on hepatic COX activity in rats, which may be achieved by increasing protein content of COX4I1. Moreover, a decreased tendency of DNMT3A protein could be one of the reasons for the lower trend of Cox4i1 methylation rate. In addition, Ligustri Lucidi Fructus may regulate the expression levels of DNMT3A and TET1 in the same direction and its mechanism is not clear.

[Effect of euodiae fructus on hepatic energy metabolism-related mechanisms of reserpine-induced asthenia cold syndrome rats].

OBJECTIVE: To discuss the effect of Euodiae Fructus on hepatic energy metabolism-related mechanisms of mitochondria of hepatic tissues of asthenia cold syndrome rats. METHOD: Rats were subcutaneously injected with Reserpine to establish the model. After the oral administration with Euodiae Fructus for 12 d, the oxygen electrode method was adopted to determine the respiration efficiency. The expressions of Cox4, Atp5b, Ucp2,Pgc-1alpha, Nrf1, Tfam mRNA were assayed by using RT-PCR method. RESULT: Euodiae Fructus 4.2 g x kg(-1) could obviously increase ST3 and RCR of asthenia cold syndrome rats, and expressions of Cox4, Ucp2 Nrf1 mRNA. It could also increase expressions of Atp5b and Pgc-1alpha mRNA, but with no statistical significance. No obvious change was observed in Tfam mRNA expression. Euodiae Fructus 4.2 g x kg(-1) could significantly increase ST3 and RCR of asthenia cold syndrome rats and Pgc-1alpha mRNA and Nrf1 mRNA expressions, and significantly decrease P/O, with no obvious impact on Cox4, AtpSb, Ucp2, Tfam mRNA expressions. CONCLUSION: Euodiae Fructus can promote mitochondrial respiratory function and oxidative phosphorylation efficiency by improving Pgc-1alpha mRNA and Nrf1 mRNA expressions and regulating Cox4 and Atp5b mRNA in mitochondrial respiratory chain. It can also strengthen mitochondrial uncoupling respiration and add heat production by activating Ucp2 mRNA expression in liver.

[Investigation on the distribution and their effects on reproduction traits of three major genes in Jinhua pigs].

The PCR-RFLP technique was applied to analyze the distribution of estrogen receptor (ESR) gene, follicle-stimulating hormone beta subunit(FSH beta) gene and prolactin receptor (PRLR) gene in three lines of Jinhua pigs. The effect of ESR, FSH beta and PRLR on the reproductive traits was analyzed by the SPSS software. The results showed that: The genotype frequencies of AA, AB, BB for ESR were 0.0237, 0.3609, 0.6154 for Jinhua pig line I, 0, 0.5333, 0.4667 for Jinhua pig line II and 0.2909, 0.6, 0.1091 for Jinhua pig line III, respectively; The genotype frequencies of AA, AB, BB for PRLR were 0.2560, 0.3929, 0.3512 for Jinhua pig line I, 0.2, 0.2667, 0.5333 for Jinhua pig line II and 0.1273, 0.4909, 0.3818 for Jinhua pig line III, respectively; But only the Jinhua pig line I had the polymorphism of FSH beta, and with the low frequency of favorable allele B (0.0120). Significant associations were found for the ESR locus with the number of born alive (NBA) in later parities, the NBA and the total number of born (TNB) of all parities(P < 0.05) and the NBA of later parities (P = 0.061) in Jinhua pig line I. The additive effects of allele B were 0.70 and 0.66 for the NBA in later parities and all parities respectively, and 0.90 and 0.84 for the TNB in later parities and all parities respectively. No significant associations were found for the PRLR locus with the reproductive traits for Jinhua pigs in all parities and significant interactions of ESR and PRLR were found for the TNB and the NBA in all parities (P < 0.05) and for the female birth weight (FBW) in later parities (P < 0.01).

Hepatoprotective effects and antioxidant, antityrosinase activities of phloretin and phloretin isonicotinyl hydrazone.

BACKGROUND: Acute liver damage is primarily induced by one of several causes, among them viral exposure, alcohol consumption, and drug and immune system issues. Agents with the ability to inhibit tyrosinase and protect against DNA damage caused by reactive oxygen species (ROS) may be therapeutically useful for the prevention or treatment of ROS-related diseases. METHODS: This investigation examined the hepatoprotective effects of phloretin and phloretin isonicotinyl hydrazone (PIH) on d-galactosamine (D-GalN)-induced acute liver damage in Kunming mice, as well as the possible mechanisms. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyl transferase (γ-GT), alkaline phosphatase (ALP), and total bilirubin (TB) as well as the histopathological changes in mouse liver sections were determined. The antioxidant effects of phloretin, quercetin, and PIH on lipid peroxidation in rat liver mitochondria in vitro, 1,1-diphenyl-2-picrylhydrazyl (DPPH) or 2,2-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) free radical scavenging activity in vitro, and supercoiled pBR322 plasmid DNA were confirmed. The experiment also examined the antityrosinase activity, inhibition type, and inhibition constant of phloretin and PIH. RESULTS: Phloretin, quercetin, or PIH significantly prevented the increase in serum ALT, AST, γ-GT, ALP, and TB in acute liver damage induced by D-GalN, and produced a marked reduction in the histopathological hepatic lesions. Phloretin, quercetin, or PIH also exhibited antioxidant effects on lipid peroxidation in rat liver mitochondria in vitro, DPPH or ABTS free radical scavenging activity in vitro, and supercoiled pBR322 plasmid DNA. Phloretin, quercetin, or PIH also exhibited good antityrosinase activity. CONCLUSION: To the best of our knowledge, this was the first study of the hepatoprotective effects of phloretin and PIH on D-GalN-induced acute liver damage in Kunming mice as well as the possible mechanisms. This was also the first study of the lipid peroxidation inhibition activity of phloretin and PIH in liver mitochondria induced by the Fe(2+)/vitamin C (Vc) system in vitro, the protective effects on supercoiled pBR322 plasmid DNA, and the antityrosinase activity of phloretin and PIH.