Chaoyu Zhu

Bio: Chaoyu Zhu is an academic researcher from Shanghai Jiao Tong University. The author has contributed to research in topics: Internal medicine & Endocrinology. The author has an hindex of 2, co-authored 5 publications receiving 21 citations.

Liraglutide Alleviates Hepatic Steatosis by Activating the TFEB-Regulated Autophagy-Lysosomal Pathway.

Abstract: Liraglutide, a glucagon-like peptide-1 receptor agonist (GLP-1RA), has been demonstrated to alleviate non-alcoholic fatty liver disease (NAFLD). However, the underlying mechanism has not been fully elucidated. Increasing evidence suggests that autophagy is involved in the pathogenesis of hepatic steatosis. In this study, we examined whether liraglutide could alleviate hepatic steatosis through autophagy-dependent lipid degradation and investigated the underlying mechanisms. Herein, the effects of liraglutide on NAFLD were evaluated in a high-fat diet (HFD)-induced mouse model of NAFLD as well as in mouse primary and HepG2 hepatocytes exposed to palmitic acid (PA). The expression of the GLP-1 receptor (GLP-1R) was measured in vivo and in vitro. Oil red O staining was performed to detect lipid accumulation in hepatocytes. Electron microscopy was used to observe the morphology of autophagic vesicles and autolysosomes. Autophagic flux activity was measured by infecting HepG2 cells with mRFP-GFP-LC3 adenovirus. The roles of GLP-1R and transcription factor EB (TFEB) in autophagy-lysosomal activation were explored using small interfering RNA. Liraglutide treatment alleviated hepatic steatosis in vivo and in vitro. In models of hepatic steatosis, microtubule-associated protein 1B light chain-3-II (LC3-II) and SQSTM1/P62 levels were elevated in parallel to blockade of autophagic flux. Liraglutide treatment restored autophagic activity by improving lysosomal function. Furthermore, treatment with autophagy inhibitor chloroquine weakened liraglutide-induced autophagy activation and lipid degradation. TFEB has been identified as a key regulator of lysosome biogenesis and autophagy. The protein levels of nuclear TFEB and its downstream targets CTSB and LAMP1 were decreased in hepatocytes treated with PA, and these decreases were reversed by liraglutide treatment. Knockdown of TFEB expression compromised the effects of liraglutide on lysosome biogenesis and hepatic lipid accumulation. Mechanistically, GLP-1R expression was decreased in HFD mouse livers as well as PA-stimulated hepatocytes, and liraglutide treatment reversed the downregulation of GLP-1R expression in vivo and in vitro. Moreover, GLP-1R inhibition could mimic the effect of the TFEB downregulation-mediated decrease in lysosome biogenesis. Thus, our findings suggest that liraglutide attenuated hepatic steatosis via restoring autophagic flux, specifically the GLP-1R-TFEB-mediated autophagy-lysosomal pathway.

Pioglitazone lowers serum retinol binding protein 4 by suppressing its expression in adipose tissue of obese rats.

Abstract: Background/Aims: Pioglitazone, a peroxisome proliferator-activated receptor γ activator, is clinically used to treat insulin resistance. However, the underlying mechanism of pioglitazone's action remains unclear. We investigated whether, and how, pioglitazone modulates serum level of retinol binding protein 4 (RBP4), an adipocytokine associated with obesity and insulin resistance. Methods: Insulin sensitivity was determined by oral glucose tolerance test, and RBP4 expression was detected by RT-PCR and Western blotting. Results: Pioglitazone treatment significantly decreased serum RBP4 levels in obese rats, which was correlated with reduced body weight and increased insulin sensitivity. Moreover, pioglitazone greatly decreased RBP4 mRNA and protein levels in adipose tissue but not in the liver. Consistently, pioglitazone treatment significantly reduced RBP4 protein expression in 3T3-L1 adipocytes but not in HepG2 cells. Conclusion: These results demonstrate that pioglitazone inhibits the level of serum RPB4 by suppressing RBP4 expression in adipose tissue of obese rats, suggesting that inhibiting RBP4 expression in adipocytes may provide a mechanism by which pioglitazone improves insulin sensitivity in insulin-resistant subjects.

Serum Glycated Albumin Levels Are Affected by Alcohol in Men of the Jinuo Ethnic Group in China.

Abstract: Aim To investigate the effects of alcohol on serum glycated albumin (GA) levels in Chinese men Methods A total of 2314 male subjects from the Jinuo ethnic group in China were enrolled Of these, 986 subjects drank alcohol frequently and 404 subjects did not Lifestyle information was gathered by using a questionnaire, and measurements of blood pressure, body mass index, blood glucose level, liver function, and kidney function were collected GA was measured by using an enzymatic method Frequent drinking was defined as a history of drinking ethanol > 80 g/d within the past two weeks Nondrinking was defined as no alcohol consumption in the past three months Subjects with an alcohol intake between 0 and 80 g/d in the past two weeks were included in the drinking-occasionally group Analysis of variance (ANOVA), correlation analysis, and linear regression were used to evaluate the effects of drinking on serum GA levels Decision tree regression (DTR) algorithm was used to evaluate the effect of features (variables) on GA levels Results We found that male subjects who drank frequently had significantly lower serum GA levels than subjects who did not drink (130 ± 17 vs 141 ± 37, ) Spearman’s correlation analysis calculated a coefficient of −0152 between drinking and GA ( ) Linear regression established that drinking was an independent predictor for GA levels with a standardized regression coefficient of −0144 ( ) Decision tree regression showed that the effect of drinking on GA levels (00283) is five times higher than that of smoking (00057) Conclusions Frequent alcohol consumption could result in decreased GA levels in men of the Jinuo ethnic group in China

Novel ceruloplasmin gene mutation causing aceruloplasminemia with diabetes in a Chinese woman: a case report

Abstract: Hereditary aceruloplasminemia (ACP) is a rare adult-onset autosomal recessive disease characterized by a ceruloplasmin (CP) gene mutation and defective or absent CP function. In the present study, we report a case of ACP in a 34-year-old Chinese woman with diabetes, fatigue, anxiety, and progressive membrane loss with low hemoglobin associated with microcytosis. The fasting glucose level was 5.6-7.96 mmol/L. Postprandial blood glucose ranged from 6.8 to 9.6 mmol/L. The Stumvoll first-phase and second-phase insulin secretion disposition indices were very low, and the serum iron content was low, even though transferrin levels were normal. Moreover, the transferrin saturation was low (5%), and the ferritin level was extremely high, above 2,000 μg/L in the patient. Furthermore, her serum CP level was extremely low ( A) in the CP gene and was diagnosed with ACP. To date, less than 60 family cases of ACP have been reported worldwide, and only two cases of ACP have been reported in China. Here, we report a case of ACP accompanied by diabetes with a novel mutation of the CP gene, which suggests that increased awareness should be highlighted in this disorder as diabetes is an important typical symptom.

Autophagy in metabolic disease and ageing.

Abstract: Autophagy is an evolutionarily conserved, lysosome-dependent catabolic process whereby cytoplasmic components, including damaged organelles, protein aggregates and lipid droplets, are degraded and their components recycled. Autophagy has an essential role in maintaining cellular homeostasis in response to intracellular stress; however, the efficiency of autophagy declines with age and overnutrition can interfere with the autophagic process. Therefore, conditions such as sarcopenic obesity, insulin resistance and type 2 diabetes mellitus (T2DM) that are characterized by metabolic derangement and intracellular stresses (including oxidative stress, inflammation and endoplasmic reticulum stress) also involve the accumulation of damaged cellular components. These conditions are prevalent in ageing populations. For example, sarcopenia is an age-related loss of skeletal muscle mass and strength that is involved in the pathogenesis of both insulin resistance and T2DM, particularly in elderly people. Impairment of autophagy results in further aggravation of diabetes-related metabolic derangements in insulin target tissues, including the liver, skeletal muscle and adipose tissue, as well as in pancreatic β-cells. This Review summarizes the role of autophagy in the pathogenesis of metabolic diseases associated with or occurring in the context of ageing, including insulin resistance, T2DM and sarcopenic obesity, and describes its potential as a therapeutic target. The cellular consequences of dysfunctional autophagy contribute to numerous diseases. In this Review, Kitada and Koya consider the relationship between impaired autophagy and age-related metabolic derangements, including insulin resistance, type 2 diabetes mellitus and sarcopenic obesity, and discuss candidate autophagy-based therapies.

GLP-1 Receptor Agonists: Beyond Their Pancreatic Effects

Abstract: Glucagon like peptide-1 (GLP-1) is an incretin secretory molecule. GLP-1 receptor agonists (GLP-1RAs) are widely used in the treatment of type 2 diabetes (T2DM) due to their attributes such as body weight loss, protection of islet β cells, promotion of islet β cell proliferation and minimal side effects. Studies have found that GLP-1R is widely distributed on pancreatic and other tissues and has multiple biological effects, such as reducing neuroinflammation, promoting nerve growth, improving heart function, suppressing appetite, delaying gastric emptying, regulating blood lipid metabolism and reducing fat deposition. Moreover, GLP-1RAs have neuroprotective, anti-infectious, cardiovascular protective, and metabolic regulatory effects, exhibiting good application prospects. Growing attention has been paid to the relationship between GLP-1RAs and tumorigenesis, development and prognosis in patient with T2DM. Here, we reviewed the therapeutic effects and possible mechanisms of action of GLP-1RAs in the nervous, cardiovascular, and endocrine systems and their correlation with metabolism, tumours and other diseases.

Pioglitazone, a Peroxisome Proliferator-Activated Receptor x03B3; Agonist, Ameliorates Chronic Kidney Disease by Enhancing Antioxidative Capacity and Attenuating Angiogenesis in the Kidney of a 5/6 Nephrectomized Rat Model.

Abstract: Background/Aims: Pioglitazone is a type of peroxisome proliferator-activated receptor γ agonist and is capable of alleviating renal ischemia-reperfusion injury. Methods: A5/6 nephrectomized rat model was established to induce renal impairments mimicking chronic kidney diseases (CKDs). The effect of pioglitazone on renal structure, function, antioxidative capacity, and angiogenesis in the nephrectomized rats was assessed. Moreover, the expression of HIF-1α, eNOS, VEGF, Flt-1 and Flk-1 was determined to reveal the possible pathways through which pioglitazone exerted its beneficial effect on CKDs. Results: Subtotal nephrectomy caused severe damages to rat renal tissues, and administration of pioglitazone dramatically restored the structure and function of the kidney, which was evidenced by Periodic acid- Schiff staining and the reduced levels of urinary proteins, blood urea nitrogen, and creatinine. Furthermore, pioglitazone decreased the level of malondialdehyde and increased the level of superoxide dismutase in the injured renal tissues, suggesting that the antioxidative capacity in the injured kidney was augmented by pioglitazone. Additionally, pioglitazone inhibited HIF-1α-dependent angiogenesis by down-regulating the expression of a panel of angiogenic factors. Conclusion: The current study demonstrates that pioglitazone benefits renal failure through activation of the antioxidative system and inhibition of angiogenesis in the injured kidney. Our study provides preliminary evidences for the potential application of this agent in the treatment of CKDs.

Protective Effects of 2-Dodecyl-6-Methoxycyclohexa-2,5 -Diene-1,4-Dione Isolated from Averrhoa Carambola L. (Oxalidaceae) Roots on High-Fat Diet-Induced Obesity and Insulin Resistance in Mice.

Abstract: Background/Aims: The roots of Averrhoa carambola L. ( Oxalidaceae ) have long been used as a traditional Chinese medicine for