scholarly journals Osteocalcin prevents insulin resistance, hepatic inflammation, and activates autophagy associated with high-fat diet–induced fatty liver hemorrhagic syndrome in aged laying hens

2021 ◽  
Vol 100 (1) ◽  
pp. 73-83
Author(s):  
X.L. Wu ◽  
X.Y. Zou ◽  
M. Zhang ◽  
H.Q. Hu ◽  
X.L. Wei ◽  
...  
2020 ◽  
Author(s):  
Xiaoling Wu ◽  
Xinyu Zou ◽  
Mi Zhang ◽  
Haiqiang Hu ◽  
Xueliang Wei ◽  
...  

Abstract Background: Osteocalcin (OCN), as an energy-regulating hormone, involves in preventing nonalcoholic steatohepatitis. Laying hens have been used as an animal model for investigating liver function and related metabolic disordersas that the synthesis of fat in laying hens is much faster than in mammals with limited adipose tissue. The aim of this study was to investigate the effects of OCN on fatty liver hemorrhagic syndrome (FLHS) in aged laying hens. Methods: Thirty 68-week-old White Plymouth laying hens were randomly assigned into conventional single-bird cages, and the cages were randomly allocated into one of three treatments: normal diet (ND + vehicle , ND+V), high-fat diet (HFD + vehicle, HFD+V), and HFD + OCN (3 μg/bird, 1 time/2 days, i.m.) for 40 days. At experimental day 30, oral glucose tolerance tests (OGTT) and insulin tolerance tests (ITT) were performed. At the end of experiment, the hens were euthanized followed blood collection. The plasma aspartate transaminase (AST), alkaline phosphatase (ALP), total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were measured using an automatic biochemistry analyzer. Pathological changes in the liver were examined under both light and transmission electron microscopes. The plasma inflammatory factors including interleukin-1 (IL-1), IL-6, and tumor Necrosis Factor-alpha (TNF-α) were analyzed by ELISA, and the gene expressions of these inflammatory factors in the liver were analyzed by Real-time PCR. And oxidative stress was evaluated using Malondialdehyde (MDA) and Glutathione peroxidase (GSH-Px) assay kits. Results: The results showed HFD hens had more severe liver haemorrhage and fibrosis than ND hens. The ultra-microstructural examination showed that hepatocytes of HFD hens appeared necrotic pyknosis associated with great intracellular electron, mitochondrial swelling, shrunk nucleus and absence of autolysosomes. OCN mitigated these pathological changes by improved HFD hens’ insulin resistance via alleviating the glucose intolerence and improving insulin sensitivity; inhibited HFD-induced oxidative stress as evidenced by decreased liver concentrations of MDA but increased GSH-Px; and reduced the inflammatory reaction with reducing blood IL-6 and TNF-α concentrations and mRNA expressions. Conclusion: These results suggest a high-fat diet promotes the FLHS development in aged hens, while OCN prevents the FLHS process through inhibiting insulin resistance, inflammatory reaction, oxidative stress and fibrosis, and acting autophagy.


2020 ◽  
Vol 318 (4) ◽  
pp. E492-E503
Author(s):  
Kenichi Tanaka ◽  
Hirokazu Takahashi ◽  
Sayaka Katagiri ◽  
Kazuyo Sasaki ◽  
Yujin Ohsugi ◽  
...  

Sodium-glucose cotransporter 2 inhibitors (SGLT2is) have been reported to improve obesity, diabetes, and nonalcoholic fatty liver disease (NAFLD) in addition to exercise training, whereas the combined effects remain to be elucidated fully. We investigated the effect of the combination of the SGLT2i canagliflozin (CAN) and exercise training in high-fat diet-induced obese mice. High-fat diet-fed mice were housed in normal cages (sedentary; Sed) or wheel cages (WCR) with or without CAN (0.03% of diet) for 4 wk. The effects on obesity, glucose metabolism, and hepatic steatosis were evaluated in four groups (Control/Sed, Control/WCR, CAN/Sed, and CAN/WCR). Numerically additive improvements were found in body weight, body fat mass, blood glucose, glucose intolerance, insulin resistance, and the fatty liver of the CAN/WCR group, whereas CAN increased food intake and reduced running distance. Exercise training alone, CAN alone, or both did not change the weight of skeletal muscle, but microarray analysis showed that each resulted in a characteristic change of gene expression in gastrocnemius muscle. In particular, in the CAN/WCR group, there was acceleration of the angiogenesis pathway and suppression of the adipogenesis pathway compared with the CAN/Sed group. In conclusion, the combination of an SGLT2i and exercise training improves obesity, insulin resistance, and NAFLD in an additive manner. Changes of gene expression in skeletal muscle may contribute, at least in part, to the improvement of obesity and insulin sensitivity.


2018 ◽  
Vol 17 (5) ◽  
pp. 0-10
Author(s):  
Hong-Shan Li ◽  
Hao Ying ◽  
Zhe-Yun He

Introduction and aim. Salidroside and curcumin (SC) formula could alleviate lipid deposition in high fat diet-induced nonalcoholic fatty liver disease (NAFLD). However, the mechanisms are still unknown, and the magnitude of potential therapeutic benefit remains understudied. Material and methods. The rats were treated with high fat diet for 14 weeks to induce NAFLD. The experiment was divided into control, model (NAFLD), SC formula and rosiglitazone groups (n = 7 in each group). Hematoxylin-eosin (H&E) staining was applied to detect liver morphological changes. Biochemical, metabolic indices and inflammation factors in liver tissue and serum were detected. Additionally, the activities of related enzymes were detected by enzyme-linked immunosorbent assay. Results. In the established rat model, typical lipid deposition and liver steatosis were observed. Liver triglyceride, free fatty acids, sera alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, fasting insulin, fasting blood glucose and homeostasis model assessment of insulin resistance were elevated in model group. Liver malondialdehyde was significantly elevated, while superoxide dismutase was significantly decreased in model group, compared with control. Moreover, tumor necrosis factor-α and Interleukin-1 were significantly produced in model group, compared with control. As a mechanism, high fat diet decreased tissue AMP-activated protein kinase (AMPK), phosphorylated AMPK, carnitine palmitoyltransferase 1 and increased inacetyl-CoA carboxylase (ACCase), phosphorylated ACCase. Importantly, these abnormal changes caused by high fat diet were reduced by SC formula administration. Conclusion. SC formula could ameliorate the injury caused by high fat diet. The effect was likely mediated via its influence on insulin resistance, lipid peroxidation injury and AMPK signaling pathway.


2010 ◽  
Vol 298 (5) ◽  
pp. G634-G642 ◽  
Author(s):  
Zhigang Wang ◽  
Tong Yao ◽  
Maria Pini ◽  
Zhanxiang Zhou ◽  
Giamila Fantuzzi ◽  
...  

Adipose tissue dysfunction, featured by insulin resistance and/or dysregulated adipokine production, plays a central role not only in disease initiation but also in the progression to nonalcoholic steatohepatitis and cirrhosis. Promising beneficial effects of betaine supplementation on nonalcoholic fatty liver disease (NAFLD) have been reported in both clinical investigations and experimental studies; however, data related to betaine therapy in NAFLD are still limited. In this study, we examined the effects of betaine supplementation on hepatic fat accumulation and injury in mice fed a high-fat diet and evaluated mechanisms underlying its hepatoprotective effects. Male C57BL/6 mice weighing 25 ± 0.5 (SE) g were divided into four groups (8 mice/group) and started on one of four treatments: control diet, control diet supplemented with betaine, high-fat diet, and high-fat diet supplemented with betaine. Betaine was supplemented in the drinking water at a concentration of 1% (wt/vol) (anhydrous). Our results showed that long-term high-fat feeding caused NAFLD in mice, which was manifested by excessive neutral fat accumulation in the liver and elevated plasma alanine aminotransferase levels. Betaine supplementation alleviated hepatic pathological changes, which were concomitant with attenuated insulin resistance as shown by improved homeostasis model assessment of basal insulin resistance values and glucose tolerance test, and corrected abnormal adipokine (adiponectin, resistin, and leptin) productions. Specifically, betaine supplementation enhanced insulin sensitivity in adipose tissue as shown by improved extracellular signal-regulated kinases 1/2 and protein kinase B activations. In adipocytes freshly isolated from mice fed a high-fat diet, pretreatment of betaine enhanced the insulin signaling pathway and improved adipokine productions. Further investigation using whole liver tissues revealed that betaine supplementation alleviated the high-fat diet-induced endoplasmic reticulum stress response in adipose tissue as shown by attenuated glucose-regulated protein 78/C/EBP homologous protein (CHOP) protein abundance and c-Jun NH2-terminal kinase activation. Our findings suggest that betaine might serve as a safe and efficacious therapeutic tool for NAFLD by improving adipose tissue function.


Diabetes ◽  
2007 ◽  
Vol 56 (10) ◽  
pp. 2501-2510 ◽  
Author(s):  
X. Huang ◽  
C. Yang ◽  
Y. Luo ◽  
C. Jin ◽  
F. Wang ◽  
...  

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Yong Xie ◽  
Yi Zhang ◽  
Zebin Guo ◽  
Hongliang Zeng ◽  
Baodong Zheng

This study aimed to investigate the effects of total alkaloids from Nelumbinis Plumula (NPA) on insulin resistance (IR) of high-fat diet- (HFD-) induced nonalcoholic fatty liver disease (NAFLD). Rats were fed with HFD for 8 weeks to induce NAFLD. Then, the effect of NPA on ameliorating IR in HFD-induced NAFLD was evaluated. Fasting serum insulin was determined using an enzyme-linked immunosorbent assay (ELISA) kit for insulin following the manufacturer’s protocol. Some inflammatory cytokines such as tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) were determined using ELISA kits to assess the inflammatory burden in rats. The results showed that HFD could induce a significant increase in blood glucose and IR in rats. However, rats treated with NPA (400 or 600 mg/kg) showed improved IR and reduction in serum inflammatory cytokines TNF-αand IL-6. Further investigation indicated that NPA could inhibit IR by restoring the insulin receptor substrate-1 (IRS-1) and suppressing the expression of c-Jun N-terminal kinase (JNK) phosphorylation. The present results supported the view that the pathogenesis of NAFLD was complex with inflammation, together with increasing serum glucose and IR. Also, JNK and IRS phosphorylation were suggested for their involvement in the modulating of IR during NAFLD progression. Therefore, NPA may serve as a potential natural remedy against IR in NAFLD.


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