1.The Association Of Serum Testosterone Level And Non-alcoholic Fatty Liver Disease In Male Patients With T2DM 2.Palmitic Acid Inhibit The Expression Of StAR Through CypD-dependent Mitochondrial Stress

[Background] The previous researches showed that non-alcoholic fatty liver disease (NAFLD) was closely associated with obesity, dyslipidemia and 2-diabetes mellitus (T2DM). The morbidity of NAFLD in patients with T2DM was much higher than that in patients without T2DM. Insulin resistance and visceral fat deposition caused by T2DM were confirmed to be the independent risk factors of NAFLD. The levels of serum total testosterone in male patients were correlated with metabolic syndrome (MetS), and epidemiological studies had shown that serum total testosterone level was negatively correlated with body mass index (BMI) and triglycerides (TG), respectively. The central obesity generated by low testosterone level is one of the risk factors of NAFLD, too. However the relationship between the level of testosterone and NAFLD is still unclear in male patients with T2DM.[Objective] To investigate the correlation of serum total serum testosterone level and non-alcoholic fatty liver disease (NAFLD) in male patients with T2DM.[Methods] The subjects of our study were 199 male patients with T2DM who had ever accepted treatment in the department of Endocrinology of Shandong Provincial Hospital affiliated to Shandong University between January 2013 and September 2015. The abdomen ultrasound was delivered to every patient to diagnose whether he had NAFLD. Then the subjects were divided into NAFLD group and non-NAFLD group according to the results of abdomen ultrasound. Furthermore, the subjects with NAFLD were classified into mild NAFLD group and moderate-severe NAFLD group according to the severity of NAFLD. The serum total testosterone level was measured using electrochemiluminescent method on Roche e601. The levels of fasting blood glucose (FBG), C peptide, insulin, triglycerides (TG), total cholesterol (TC) and the other serological indicators were measured with fasting blood. The insulin resistance was measured by homeostasis model assessment for insulin resistance (HOMA-IR). The correlation of the level of serum total testosterone and NAFLD was analyzed by nonparametric test and ordinal regression. The connection of testosterone level and the degree of severity of NAFLD was measured by t-est. The relevance of testosterone level and the other serological indicators were measured by Spearman rank correlation.[Result] ① The serum total testosterone levels were lower in patients with NAFLD than in those without NAFLD. and the difference was statistically significant (3.29(2.54-4.21) Vs 4.91(3.48-5.99), P value<0.01). ② Orderly regression analysis showed that the levels of testosterone had an odd ratio (OR) (95% confidence interval (CI)) of 0.68 (95%CI:0.55-0.84, Pvalue<0.01, after adjusting for age, BMI, glutamic oxalacetic transaminase (ALT) y-glutamyl transpeptadase (GGT) ③ Testosterone level was lower in patients with moderate-severe NAFLD than those with mild NAFLD(3.06±1.11 Vs 3.65±1.45, P value<0.05).[Conclusion] Male T2DM patients with lower serum testosterone level were at a higher risk for NAFLD. Low testosterone level was an independent risk factor for NAFLD.[Background] Clinical researches indicated that the serum TT levels of men who were overweight and obese were significantly lower than the of men with normal body weight. Researches showed that mitochondrial dysfunction could reducing the level of testosterone via effecting steroidogenic acute regulatory (StAR) protein which is the first and rate-limiting step of the synthesis of testosterone. Cyclophilin D (CypD) is a key component of mitochondrial permeability transition pore (mPTP), and the CypD-dependent mPTP opening is associated with the dysfunction of mitochondria. However, whether obesity and dyslipidemia could decline the synthesis of testosterone though effect the expression of CypD is still unclear.[Objective] To investigate the impact of PA on the synthesis of testosterone in the mice leydig cells, and its mechanism.[Methods] The leydig cells (TM3 cells) were incubated in vitro, and then the cells were divided into 4 groups, including control group, PA (0.4mM) treated group, CsA treated group and PA+CsA treated group. After the cells were treated for 24h, the expression of StAR and CypD was measured by Western Blot analysising and RT-PCR, respectively. MitoSOX Red was given to measure the concentration of ROS in mitochondria. JC-I was used to detect mitochondrial membrane potential (Δψm). The mitochondria was isolated from TM3 cells to evaluate the level of ATP and lipid peroxidation(measured by MDA).[Results] ①PA could inhibit the synthesis of testosterone in the leydig cells by restraining the expression of StAR. ② PA could up regulate the expression of CypD, and lead to mitochondrial stress, including the increased content of mitochondrial ROS, decreased concentration of ATP, collapsed Δψm and lipid peroxidation. ③ The severity of mitochondrial stress of the PA+CsA group were improved compared with the PA group. ④The expression of StAR was elevated in the PA+CsA group in comparison with the PA group.[Conclusion] PA could inhibit the expression of StAR through CypD-dependent mitochondrial stress.