Objective Recent studies have found that the levels of plasma amino acids, such as branched-chain amino acids and aromatic amino acids, were associated with visceral obesity, insulin resistance, future development of diabetes and cardiovascular diseases. However, few studies have involved a Chinese Han population. This study aimed to examine the association between amino acid profile and metabolic syndrome (MetS) and its components in the Chinese Han population. Methods This is a cross-sectional study, which enrolled a cohort of 473 participants from a community. We employed the isotope internal standard method to determine the plasma concentrations of 28 amino acids using high-performance liquid chromatography-tandem mass spectrometry (LC/MS). Participants were divided into MetS ( n = 72) and non-MetS groups ( n = 401) to analyze the association between amino acids and MetS and its components. Results The prevalence of MetS was 15.2% according to the criteria. Plasma concentrations of isoleucine (Ile), leucine (Leu), valine (Val), tyrosine (Tyr), tryptophan (Trp), phenylalanine (Phe), glutamic acid (Glu), aspartic acid (Asp), alanine (Ala), histidine (His), methionine (Met), asparagine (Asn), and proline (Pro) were significantly higher in the MetS group than those in the non-MetS group ( P < 0.05), but taurine (Tau) was significantly lower ( P < 0.05). When MetS components were increased, the concentrations of these 13 amino acids significantly increased ( P < 0.05), but Tau concentration was significantly decreased ( P < 0.05). We extracted the amino acid profile by principal component analysis (PCA), PC1 and PC2, which extracted from the 14 amino acids, were significantly associated with MetS (odds ratio, 95% confidence interval: 1.723, 1.325–2.085 and 1.325, 1.043–1.684, respectively). A total of 260 non-MetS participants were followed up effectively, and 42 participants developed new-onset MetS within 5 years. We found that the amino acid profile of PC1 was linked to the occurrence of future MetS. Decreased Tau was correlated with the future development of MetS. Conclusion Participants with MetS exhibit an abnormal amino acid profile, and its components gradually increase when these amino acids are altered. Amino acid PCA profile can be employed for assessing and monitoring MetS risk. Finally, decreased Tau may be linked to the future development of MetS.

Introduction: Pseudohypoparathyroidism (PHP) indicates a group of rare disorders characterized by end-organ resistance to various hormones, primarily parathyroid hormone (PTH). One of its most common type is PHP-Ia, which is caused by maternally inherited inactivating mutations inGNAS.In this report, we present a Chinese girl with typical features of PHP-Ia and a novel mutation of theGNASgene. Patient concerns: A 9-year-old Chinese girl presented with recurrent epileptic seizure. Diagnosis: Biochemical and imaging findings were consistent with PHP-Ia, including typical Albright hereditary osteodystrophy phenotype (short stature, round face, brachydactyly, and mild mental retardation), PTH resistance (hypocalcemia, hyperphosphatemia, elevated serum PTH, and multiple intracranial calcification) and thyroid stimulating hormone resistance (elevated serum thyroid stimulating hormone). Interventions: The patient was given 1 alpha-hydroxylated vitamin D (calcitriol, 0.5 ug/d), calcium carbonate and vitamin D(3)tablets (1.5 g/d, including 600 mg calcium and 125 IU vitamin D-3). DNA analysis of theGNASgene was performed for the whole family. Outcomes: Investigation of theGNASgene revealed a novel mutation c.313delG (p.Glu105Lysfs*7) in the patient, as well as her mother. So the diagnosis of PHP-Ia was confirmed. Conclusion: The study further expands the spectrum of knownGNASmutations associated with PHP and lay emphasis on the genetic analysis ofGNASgene for identifying genetic abnormalities as well as making diagnosis and differentiation of various subtypes of PHP.

Background: Gitelman syndrome (GS) is an autosomal recessive disorder caused by genic mutations of SLC12A3 (Solute carrier family 12 member 3), which encodes the Na-Cl cotransporter (NCC), and presents with characteristic metabolic abnormalities, including hypokalemia, metabolic alkalosis, hypomagnesemia, and hypocalciuria. In this study, we report a case of a GS pedigree, including analysis of GS-associated gene mutations. Methods: We performed next-generation sequencing analysis and Sanger sequencing to explore the SLC12A3 mutations in a GS pedigree that included a 35-year-old female patient with GS and five family members within three generations. Furthermore, we summarized their clinical manifestations and analyzed laboratory parameters related to GS. Results: The female proband (the patient with GS) presented with intermittent fatigue and transient periods of tetany, along with significant hypokalemia, hypomagnesemia, and hypocalciuria. All other members of the pedigree had normal laboratory results without obvious GS-related symptoms. Genetic analysis of the SLC12A3 gene identified two novel missense mutations (c.1919A > G, p.N640S in exon 15; c.2522A > G, p.D841G in exon 21) in the patient with GS. Moreover, we demonstrated that her mother, younger maternal uncle, and cousin were carriers of one mutation (c.1919A > G), and her father was the carrier of the other (c.2522A > G). Conclusion: This is the first report of these two novel pathogenic variants of SLC12A3 and their contribution to GS. Further functional studies are particularly warranted to explore the underlying molecular mechanisms.

Aims: Genetic variations in the PI3K/AKT/mTOR signaling pathway may be associated with an increasing risk of obesity and diabetes. In this study, we aimed to test whether polymorphisms in the PIK3CA (catalytic subunit of PI3K), AKT1, AKT2, and FRAP1 (mTOR) genes were associated with the risk of type 2 diabetes mellitus (T2DM) among Chinese population.Methods: A case-control study was conducted and included 248 cases with T2DM and 101 controls. A total of 28 tagSNPs from the 4 genes were chosen based on HapMap datasets and these were genotyped using a MassARRAY Compact Analyzer.Results: Individuals carrying the rs2494746 CG/GG or rs2494738GA/GG genotype in AKT1 had a higher risk of T2DM, compared with those carrying homozygous variants (adjusted OR = 1.79, 95% CI: 1.05-3.05, P = 0.03 for rs2494746; adjusted OR = 1.58, 95% CI: 1.19-2.10, P = 0.02 for rs2494738). Furthermore, we found that haplotype GC in the AKT1 gene comprised rs2494738 and rs3803304, indicating a significant association with T2DM (OR = 1.08, 95% CI: 1.01-1.15, P = 0.03). Finally, generalized multifactor dimensionality reduction (GMDR) analysis indicated that the best interactive model included 3 polymorphisms: rs2494746 (AKT1), rs4802071 (AKT2), and rs4845856 (FRAP1).Conclusions: Our study suggests that PI3K/AKT/mTOR pathway genes may participate in the development of T2DM. (C) 2017 Elsevier B.V. All rights reserved.

Liver X receptors (LXR) are deemed as potential drug targets for atherosclerosis, whereas a role in adipose tissue expansion and its relation to insulin sensitivity remains unclear. To assess the metabolic effects of LXR activation, C57BL/6 mice on a high-fat diet (HFD) were treated with the dual LXRα/β agonist T0901317 (30 mg/kg per day) for 3 weeks. Differentiated 3T3-L1 was used for analysing the effect of T0901317 on glucose uptake.T0901317 reduced fat mass, accompanied by a massive fatty liver and lower adipokine levels in circulation of HFD mice. Increased adipocyte apoptosis and macrophage infiltration were found in epididymal fat of T0901317-treated HFD mice. In addition, T0901317 treatment promoted basal lipolysis, but blunted the anti-lipolytic action of insulin. Furthermore, LXR activation antagonized PPARγ target genes in epididymal fat and PPARγ-PPRE binding activity in 3T3-L1 adipocytes. Although the glucose tolerance was comparable to that in vehicle-treated HFD mice, the insulin tolerance was significantly decreased in T0901317-treated HFD mice, indicating decreased insulin sensitivity by T0901317 administration, and which was further supported by impaired insulin signalling found in epididymal fat and decreased insulin-induced glucose uptake in 3T3-L1 by T0901317administration. These findings reveal that LXR activation impairs adipose expansion which contributes to decreased insulin sensitivity.

Autophagy is believed to play an important role in maintaining homeostasis in pancreatic β-cells during insulin resistance. This study investigated the role of autophagy in β-cell damage induced by cholesterol and its possible activation mechanism. Rat and mouse pancreatic β-cell lines INS-1 and βTC-6 were incubated with cholesterol alone or in combination with autophagy inhibitors E-64d/Pepstatin A or bafilomycin A1. DAPI staining, western blotting, transmission electron microscopy and immunofluorescence were conducted to assess the effects of autophagy inhibitors on cholesterol-induced apoptosis and autophagy activity. An increase in FITC-LC3 fluorescence dots, autophagic vacuoles and LC3-II protein indicated that autophagy was activated in cells treated with cholesterol. This was further confirmed by blocking the natural turnover processes in lysosomes and autolysosomes with autophagy inhibitors, suggesting enhanced autophagic activity rather than blockage of autophagy. Furthermore, inhibition of autophagy significantly augmented the activation of caspase 3 and the percentage of cholesterol-induced apoptotic nuclei. These results demonstrate that autophagy plays a protective role against cholesterol-induced apoptosis in pancreatic β-cells.

Oxidative stress is considered to be an important factor in producing lethal hepatocyte injury associated with nonalcoholic fatty liver disease (NAFLD). Glucose fluctuation, more pronounced in patients with diabetes, has been recognized as an even stronger oxidative stress inducer than the sustained hyperglycemia. Here, we investigated the role of glucose variability in the development of the NAFLD based on hepatocyte apoptosis and possible mechanisms. To achieve this goal we studied C57BL/6J mice that were maintained on a high fat diet (HFD) and injected with glucose (3 g/kg) twice daily to induce intermittent high glucose (IHG). We also studied hepatic L02 cells incubated with palmitic acid (PA) to induce steatosis. The following experimental groups were compared: normal glucose (NG), sustained high glucose (SHG) and IHG with or without PA. We found that, although hepatic enzyme levels and liver lipid deposition were comparable between HFD mice injected with glucose or saline, the glucose injected mice displayed marked hepatocyte apoptosis and inflammation, accompanied by increased lipid peroxide in liver. In vitro, in the presence of PA, IHG increased L02 cell apoptosis and oxidative stress and produced pronounced mitochondrial dysfunction relative to the NG and SHG groups. Furthermore, treatment with the mitochondrial permeability transition (MPT) inhibitor, cyclosporin A (1.5 μmol/l), prevented mitochondrial dysfunction, oxidative stress and hepatocyte apoptosis. Our data suggests that IHG under lipotoxicity might contribute to the development of NAFLD by increasing oxidative stress and hepatocyte apoptosis via MPT and its related mitochondrial dysfunction.

Metabolic syndrome (MetS) has been identified to be associated with a state of chronic, low-grade inflammation in adipose tissue. Lipoxins are endogenously generated from arachidonic acid, and exhibit anti-inflammatory actions. Currently, there is no available cohort study identifying the association between serum lipoxins level and MetS. Here we investigate the relationship between serum lipoxin A4 (LXA4) level and the risk of incident MetS in a middle-aged Chinese population. A total 624 participants aged 40-65 years were enrolled at baseline, with 417 (including 333 MetS absence) of them were followed up at 2.5 years. Abdominal visceral fat area (VFA) and abdominal subcutaneous fat area (SFA) were determined using MRI. Serum lipoxin A4 levels were measured by ELISA. At baseline, serum LXA4 levels were significantly correlated with a cluster of traditional MetS risk factors related to obesity (P ≤ 0.05). A higher incidence of new Mets was found in the participants of the lowest tertile of LXA4 levels as compared with that in participants of the highest tertile (P = 0.025). Low serum LXA4 levels [OR 2.607(1.151-5.909), P = 0.022] and high VFA [OR 2.571(1.176-5.620), P = 0.018] were associated with an increased incident Mets, respectively, which remained statistically significant after adjustment for age, gender, current smoking, and alcohol drinking status. Logistic regression analysis suggested a combination of low serum LXA4 levels and high WC/VFA might optimize the prediction of incident Mets in middle-aged Chinese population [OR 4.897/4.967, P = 0.009/0.003]. Decrease in serum LXA4 level and increase in VFA are independent predictors of incident Mets in a population-based cohort, and a combination of them enhances the prognostic value of incident Mets. Taken together, our data suggest that serum LXA4 levels might be useful for early detection and prevention of Mets.

Liver X receptors (LXRs) have been recognized as a promising therapeutic target for atherosclerosis; however, their role in insulin sensitivity is controversial. Adiponectin plays a unique role in maintaining insulin sensitivity. Currently, no systematic experiments elucidating the role of LXR activation in insulin function based on adiponectin signaling have been reported. Here, we investigated the role of LXR activation in insulin resistance based on adiponectin signaling, and possible mechanisms. C57BL/6 mice maintained on a regular chow received the LXR agonist, T0901317 (30 mg/kg.d) for 3 weeks by intraperitoneal injection, and differentiated 3T3-L1 adipocytes were treated with T0901317 or GW3965. T0901317 treatment induced significant insulin resistance in C57BL/6 mice. It decreased adiponectin gene transcription in epididymal fat, as well as serum adiponectin levels. Activity of AMPK, a key mediator of adiponectin signaling, was also decreased, resulting in decreased Glut-4 membrane translocation in epididymal fat. In contrast, adiponectin activity was not changed in the liver of T0901317 treated mice. In vitro, both T0901317 and GW3965 decreased adiponectin expression in adipocytes in a dose-dependent manner, an effect which was diminished by LXRα silencing. ChIP-qPCR studies demonstrated that T0901317 decreased the binding of PPARγ to the PPAR-responsive element (PPRE) of the adiponectin promoter in a dose-dependent manner. Furthermore, T0901317 exerted an antagonistic effect on the expression of adiponectin in adipocytes co-treated with 3 µM Pioglitazone. In luciferase reporter gene assays, T0901317 dose-dependently inhibited PPRE-Luc activity in HEK293 cells co-transfected with LXRα and PPARγ. These results suggest that LXR activation induces insulin resistance with decreased adiponectin signaling in epididymal fat, probably due to negative regulation of PPARγ signaling. These findings indicate that the potential of LXR activation as a therapeutic target for atherosclerosis may be limited by the possibility of exacerbating insulin resistance-related disease.

目的 探讨血管紧张素原基因M235T多态性与糖尿病慢性肾脏疾病(CKD)的关系. 方法 选取健康对照(N3者203名与T2DM患者311例(UAlb/Cr＜30 mg/g组158例,30 mg/g≤UAlb/Cr＜299mg/g组111例和UAlb/Cr≥300 mg/g组42例),采用聚合酶链反应-限制性片断长度多态性技术进行M235T位点多态性检测. 结果 NC组和T2DM组基因型分布MM、MT、TT分别为2.5％、29.6％、68.0％和2.6％、28.3％、69.1％,两组等位基因M、T频率分别为17.2％、82.8％和16.7％、83.3％.4组间基因型分布比较差异无统计学意义,等位基因频率比较差异无统计学意义.进一步按照性别比较,4组基因型分布比较差异无统计学意义,等位基因频率比较差异无统计学意义. 结论 血管紧张素原基因M235T多态性可能与CKD无相关性.

The fractalkine/CX3CR1 axis plays an important role in regulating glucose and lipid metabolism. However, the role of fractalkine in metabolic disorders remains to be fully elucidated. We selected 887 Chinese (40–65 years old) at baseline, with a subgroup of 459 participants examined again 2 years later. The relationship of serum fractalkine levels with the metabolic syndrome (MetS) and its components was investigated. At baseline, participants with MetS had higher fractalkine concentrations than their counterparts without MetS (P<0.001). At the 2-year follow-up, participants in the highest quartile of baseline fractalkine exhibited higher values for body mass index, waist circumference, waist-to-hip ratio, body fat percentage, glucose, insulin, total cholesterol, triglycerides (TG), and homeostasis model assessment of insulin resistance (HOMA-IR) and lower value for high density lipoprotein-cholesterol (HDL-c) (allP<0.05). Among 390 participants without MetS at baseline, 45 developed it at year 2. Even after multiple adjustments for visceral adipose tissue area, HOMA-IR, C-reactive protein (CRP), or TG and HDL-c, baseline fractalkine predicted the development of MetS (OR = 7.18, 95%CI: 2.28–18.59). In conclusion, circulating fractalkine predicts the development of the MetS independently of central obesity, CRP, insulin resistance, and dyslipidemia.

OBJECTIVE:To investigate the relationship between serum uric acid (UA) level and abdominal obesity or metabolic syndrome (MS).METHODS:A total of 875 subjects, with 350 males and 525 females, aged 40-65 years old, were enrolled in this study. The clinical and biochemical data were collected and MRI was used to assess the visceral and subcutaneous adipose tissues. The relationships between UA level and abdominal obesity or MS were analyzed, and the cut-off values of UA for abdominal obesity and MS were determined.RESULTS:Raised risks of abdominal obesity(OR = 4.35, 95%CI 1.91-9.90 in males; OR = 5.44, 95%CI 2.41-12.31 in females) and MS(OR = 4.47, 95%CI 2.08-9.62 in males; OR = 11.62, 95%CI 3.43-39.37 in females) were observed with the increase of UA level. The multiple logistic regression analysis showed that UA was an independent risk factor for hypertriglyceridemia(OR = 2.23, 95%CI 1.02-4.87 in males; OR = 3.04, 95%CI 1.49-6.23 in females) in all subjects and for abdominal obesity(OR = 3.23, 95%CI 1.32-7.91) and hypertension (OR = 2.35, 95%CI 1.37-4.05) in the females. Among the females, the regression line analyzed by simple correlation indicated that the UA level of 244.0 µmol/L was corresponded to the visceral adipose tissue area of 80 cm(2). The optimal cut-off point of UA for the diagnosis of MS was 258.8 µmol/L determined by the receiver operating characteristic curve.CONCLUSIONS:The level of UA is closely correlated with abdominal obesity and MS in the middle-aged Chinese. The elevated UA level is an independent risk factor for abdominal obesity and MS in the female.