ACTA ENDOCRINOLOGICA (BUC)

Background. The purpose of this study was to explore the influencing factors of serum uric acid (SUA) level and related gene polymorphisms in the healthy population. Methods. A total of 346 healthy individuals screened from different areas in Shenyang City and 195 patients with high SUA levels were included. Results. The levels of TC (total cholesterol), HDL-C (high-density lipoprotein cholesterol), LDL-C (lowdensity lipoprotein cholesterol), TG (triglycerides), GLU (blood glucose) ALT (alanine aminotransferase), TBA (total bile acid), TBIL (total bilirubin), CR (creatinine) and CYSC (Cystatin C) were statistically different between the healthy and hyperuricemia population (P<0.05). However, there was no statistical difference in the UA level between the two groups (P>0.05). After adjusting for UA, TC, HDL-C, LDL-C, GLU, TBIL and CYSC, the additive and recessive models of rs2231142 were statistically significant in females (P<0.05). For males, haplotypes of A-C-A-A-G-G, A-CG- C-G-G and A-T-G-A-A-G had significant difference between the healthy and hyperuricemia population (P<0.05). For females, the haplotypes of A-C-G-C-G-G and A-T-A-CA- T had significant differences (P<0.05). Conclusion. The distributions of SLC2A9 (solute carrier family 2 and facilitated glucose transporter member 9), ABCG2 (ATP-binding cassette G2), GCKR (glucokinase regulatory protein), KCNQ1, IGFIR (Insulin-like growth factor-I receptor) and VEGFR (Vascular Endothelial Growth Factor Receptor) were balanced in the population in Shenyang City. The haplotypes of A-C-A-A-G-G, A-CG- C-G-G and A-T-G-A-A-G were the influencing factors of high SUA in the population in Shenyang City.

Objective. To observe the impact of quercetin and isoquercitrin on gluconeogenesis in hepatocytes. Methods. Mouse primary hepatocytes were cultured with lactic acid and pyruvic acid. After treatment with quercetin and isoquercitrin for 24 hours, the glucose concentration in the culture supernatant was determined. RT-PCR was used to detect the mRNAs of PEPCK, G6Pase, LKB1, and AMPKα. Protein levels of LKB1, AMPKα, and Thr172 phosphorylation were evaluated by Western blot. Results. The glucose concentration in the gluconeogenesis group (GN) was significantly higher than in the control group (C), but the glucose concentrations in the high level quercetin(group 80Q) and high level isoquercitrin (group 80I) were significantly lower than in the group GN, P<0.01. In the group 80Q, and group 80I, the mRNA levels of PEPCK and LKB1were significantly lower than in the group GN (P<0.01), and the G6Pase mRNA were significantly lower than in the group GN (P<0.05). The protein levels of LKB1 and the phosphorylation of AMPKα Thr172 in the group 80Q, group 40I, and group 80I were higher than in the group GN. The effects of quercetin and isoquercitrin on LKB1 and AMPKα were similar to those of metformin. Conclusions. Quercetin and isoquercitrin inhibit gluconeogenesis in hepatocytes, which may be related to the LKB1 upregulation and phosphorylation of AMPKα.

Objective. In this study we investigated the effect of dorsomedial hypothalamus (DMH) neuropeptide Y (NPY) knock-down on hepatic insulin sensitivity in high-fat (HF) diet-fed rats. Methods. Forty-eight Sprague-Dawley rats were randomly assigned to receive bilateral DMH injections of adeno-associated virus AAVshNPY or AAVshCTL and then accessed to regular chow. Five weeks after viral injection, half rats in each group were given access to the HF diet. At 16 weeks, rat livers were collected. Insulin receptor substrate-1 (IRS-1) and phosphoinositide 3-kinase (PI3K) mRNA expression was measured by qRT-PCR. Blood glucose levels were measured by the oxidase method, serum insulin, triglyceride, and TC levels were measured by Elisa. Pathological changes in the liver were assessed by hematoxylin-eosin (HE) staining. AKT, p-AKT, and GSK-3 levels were measured by western blotting. Results. Compared with AAVshCTL-injected rats, AAVshNPY-injected rats showed a significant decrease in blood glucose concentrations; serum insulin, triglyceride, and TC; HOMA-IR; and IRS-1 and PI3K mRNA levels (P<0.05). ISI, GSK-3, and p-AKT levels were significantly increased (P<0.05). HE staining showed that AAVshNPYinjected rats fed the HF diet had mild fatty degeneration. Conclusion. These results suggest that DMH NPY knock-down improves hepatic insulin sensitivity in HF diet-fed rats by activating the hepatic PI3K/AKT insulin signalling pathway.

Aims. This study investigated the relationship between proteinuria levels, clinicopathological features, and renal prognoses in Chinese patients with type 2 diabetes mellitus (T2DM) and diabetic nephropathy (DN). Methods. Three hundred patients with T2DM and biopsy-proven DN were enrolled. Patients were stratified by 24-h proteinuria levels: Group 1:≤1g/24h); Group 2:1-3g/24h; and Group 3:≥3g/24h. Renal outcomes were defined as having reached end-stage renal disease (ESRD). The proteinuria level’s influence on the renal outcomes was evaluated using Cox regression analysis. Results. Among subgroups stratified by proteinuria levels, systolic blood pressure, serum creatinine, BUN, cholesterol, DR and hypertension incidence, the incidences of patients who progressed to ESRD were the lowest in group 1 (P<0.05). However, eGFR, serum albumin and hemoglobin were highest in group 1. Patients with higher proteinuria levels had much lower five-year renal survival rates. Univariate analyses revealed that higher proteinuria levels were significant clinical predictors of renal prognosis (P<0.05), although they were not independent risk factors for progression to ESRD in the multivariate Cox proportional hazard analysis (P>0.05). Conclusions. The higher the level of proteinuria, the lower the 5-year renal survival rate of DN patients, but there was no significant correlation between proteinuria level and 5-year renal survival rate. Other factors in the proteinuria group may have more significant effects on the 5-year renal survival rate, such as lower baseline eGFR, serum albumin, hemoglobin and higher cholesterol, higher incidences of DR and more severe lesions.

Context. To analyze the dynamic changes of serum thyrotrophin receptor antibody (TRAb) and thyroid peroxidase antibody (TPOAb) in Graves’ disease (GD) patients before and after radioactive iodine (RAI) treatment and to investigate if TRAb and TPOAb play a role in the occurrence of early hypothyroidism after 131I therapy for Graves’ hyperthyroidism. Subjects and Methods. A total of 240 patients newly diagnosed with GD were selected to study. A clinical and laboratory assessment was performed before and at 3, 6, and 12 months after 131I therapy. Chemiluminescent immunoassays were used to detect serum free triiodothyronine (FT3), free thyroxine (FT4), sensitive thyroid-stimulating hormone (TSH) and TPOAb concentration. Radio-receptor assay was used to measure serum TRAb concentration. According to the early onset of hypothyroidism in a year after RAI therapy, patients were divided into early hypothyroidism group (group A) and non-early hypothyroidism group (group B). Results. In both groups, serum TRAb and TPOAb increased at 3 months, reached the highest level at 6 months and returned to the baseline at 12 months after RAI therapy. TRAb showed a significant difference between the two groups at 6 months (P<0.01). Serum TPOAb in group A was higher than that in group B before and at 3, 6, 12 months after RAI therapy (P<0.05). Conclusions. Serum TRAb and TPOAb are closely related to the occurrence of the early hypothyroidism, and play an important role in judging prognosis after 131I treatment in Graves’ disease.

Background. Thyroid hormone participates in lipid metabolism regulation. However, the effects on triacyleride or triacylglycerol metabolism are complex and not fully clarified yet. In this study, we try to identify novel thyroid hormone-targeting lipogenic metabolic genes and analyze their molecular regulative mechanism. Method. Thirty-five promoters of twenty-nine human lipogenic regulative enzyme genes were constructed into pXP1 luciferase reporter plasmid (PFK2/FBP2-luc) and transfected into HeGP2 cells, respectively. Gene expression induced by triiodothyronine (T3) was detected by luciferase assay. The T3-activated gene promoter was then analyzed by sequence analysis, deletion and mutation, and electrophoretic mobility shift assay (EMSA). Results. After 10 nM T3 stimulation for 36 h, phosphogluconate dehydrogenase, malic enzyme, Glycerol- 3-phosphate acyltransferase (GPAT) 3, and 1-acylglycerol-3- phosphate O-acyltransferase (AGPAT) 2 were significantly activated, respectively. A AGGTCA-like-direct-repeat-4 consensus thyroid hormone response element (DR4-TRE)- like sequence was found in the GPAT3 promoter, which was then verified to be necessary for T3-induced GPAT3 activation by gene deletion and mutation analysis. EMSA further identified that T3-thyroid receptor (TR) α-retinoid-X receptor (RXR) complex directly bound on the GPAT3 promoter. Conclusion. Triiodothyronine could activate the GPAT3 through DR4-TRE-like sequence binding to participate in lipogenic regulation. AGPAT2 may be another thyroid hormone target enzyme.

Background. This study aimed to assess the mechanism through which Wnt/ beta - catenin signaling pathway, and StarD7, prometes testosterone synthesis, and to explore a new pathway for the regulation of testosterone synthesis. Animals and Methods. Leydig cells were isolated from male Sprague-Dawley rats divided into four groups and treated with Annexin 5 in concentration of 0, 0.1, 1 and 10 nmol/L. Testosterone secretion, expression of StarD7, StarD7 mRNA, β-catenin and changes of β – catenin localization in Leydig cells of testis of rats were tested in the four groups. Results. mRNA and protein levels of StarD7 and β-catenin increased significantly, upon stimulation with 1 nmol/L annexin 5. Accumulation of β-catenin inside the cells and the nucleus, was observed by immunofluorescence staining, in cells treated with annexin 5. These findings indicate a possible role of StarD7 and β-catenin in the process of annexin5-mediated stimulation of testosterone synthesis. Conclusions. Wnt/β-catenin signaling pathway and StarD7 are involved in the process of annexin5 stimulation of testosterone synthesis. Activation of Wnt/ β-catenin signaling pathway by Annexin5, and increase in StarD7 expression lead to elevated expression of key regulatory enzymes in testosterone synthesis, thus promoting testosterone synthesis.

Objective. Endoplasmic reticulum stress (ERS) is suspected as an important factor in the initiation of insulin resistance. Aim. To explore the effects of exendin-4 (Ex- 4) on the endoplasmic reticulum stress (ERS)-mediated insulin resistance in 3T3-L1 adipocytes. In our study, 3T3-L1 adipocytes were pre-treated with ERS inhibitors tauroursodeoxycholic acid (TUDCA), Ex-4 and an ERS inducer tunicamycin (TM) then induced insulin resistance. Glucose consumption of the adipocytes was measured. Western blots determined the protein levels of ERS markers and insulin signaling pathway. Results. TM treatment reduced insulin-stimulated glucose consumption by 19.7% in 3T3-L1 adipocytes. This repression was blunted by 24h pre-treatment with TUDCA or Ex-4. Ex-4 augmented insulin-stimulated glucose consumption in adipocytes by 14.9%. Western blotting showed that TM treatment significantly increased the ER stress markers including p-IRE, p-JNK, p-PERK, p-eIF2a and ATF6 expression, whereas 24h pre-treatment of adipocytes with TUDCA or Ex-4 alleviated the ER stress. Ex-4 alleviates ERS-induced insulin resistance by upregulating the expression of phosphorylated Akt. Conclusion. ERs mediates insulin resistance in 3T3-L1 adipocytes, and exendin-4 significantly improves this insulin resistance.

The aim of this study was to examine the highglucose and high fatty acid status effect on the development of atherosclerosis. Materials and Methods. We used rat thoracic aorta smooth muscle cell line A7r5. We investigated mechanisms underlying high-glucose and high fatty acid (oleic acid) conditions on vascular smooth muscle cell (VSMC) mimicking concurrent status of diabetes and dyslipidemia. Results. Glucose-oleic acid stimulated cell proliferation and migration while the proliferating cell nuclear antigen (PCNA) level and matrix metalloproteinase (MMP)-2 were activated. In addition, the expressions of connective tissue growth factor (CTGF) and fatty acid synthase (FASN) enhanced by glucose-oleic acid were increased. The proliferation signal mediated by glucoseoleic acid condition was demonstrated via CTGF/FASN, while MMP-2 was regulated by CTGF but not FASN. Conclusion. Oleic acid in the presence of high glucose level can induce VSMC proliferation and migration leading to diabetes-associated vascular atherosclerosis. Furthermore, via activation of CTGF, increased expression of FASN suggested a possibility of lipogenesis in VSMC which may also contribute to diabetes-associated vascular atherosclerosis.

Objective. Exercise intensity is one of the most important factors that determines the effects of exercise; however, there is little known about the acute glycemic control of different exercise intensities on patients with Type 2 Diabetes Mellitus (T2DM). Here we aimed at exploring the influence of a single bout of exercise with different intensities on blood glucose levels in T2DM patients. Methods. Fifteen subjects (54.7 ± 5.8 years old) participated in a session of walking (WG), jogging (JG), or sedentary control (CG) in a randomized order on three different days. Distances in both WG and JG were set as 2 Km with a speed set as 4~4.5 Km/h for walking and 5~6 Km/h for jogging based on pretrial test. Blood glucose levels at fasting (~6:30am), pre-exercise (~8:30am), post-exercise (~9am), 11am and 4pm were detected. Results. Walking and jogging reached approximately moderate and high intensity based on the immediate post-exercise heart rate and RPE scores. Blood glucose levels at fasting, pre-exercise and 4pm were not substantially different among all groups (p > 0.05). JG had a significantly lower post-exercise blood glucose level (p < 0.05) when compared with CG and WG. The blood glucose level at 11am was notably lower in WG and JG than in CG (p < 0.05). Conclusions. Both a single bout of jogging and walking can lower postprandial blood glucose levels in T2DM patients. When matched for exercise distance, jogging represents a more effective strategy to immediately lower postprandial glucose levels than walking.