CoQ10 protects against acetaminophen-induced liver injury by enhancing mitophagy.

Coenzyme Q10 (CoQ10), which is a key cofactor of the electron transport chain in the mitochondria has shown many beneficial effects on liver diseases. However, the mechanisms of CoQ10 protective role on the acetaminophen (APAP)-induced liver injury are elusive and unclear. In this study, we further investigated the CoQ10 therapeutic effects on APAP-overdose liver injury. C57BL/6 J mice were intraperitoneally treated with APAP to induce liver injury. CoQ10 (5 mg/kg) was given to mice at 1.5 h after APAP treatment. The results showed that hepatic CoQ10 levels were decreased during the APAP-induced hepatotoxicity and preceded serum ALT elevation. Treatment of CoQ10 significantly improved the liver injury induced by APAP. Moreover, CoQ10 treatment decreased the ROS levels and promoted the antioxidative related gene expression in APAP overdose mice. Importantly, results showed that even though CoQ10 had no effects on the mtDNA copy number and the expression of genes related to mitochondrial biogenesis, it significantly improved the mitochondrial complex I and V activities and promoted the mitophagy in APAP-overdose mice. To further authenticate mitophagy role in CoQ10-mediated improved liver injury in vivo, we administrated APAP-overdose mice with chloroquine 1 h prior to APAP treatment and found that chloroquine treatment functionally abrogated the CoQ10 protective role on APAP overdose mice. To conclude, this study provides evidence that CoQ10 activates mitophagy to protect against APAP-induced liver injury. Therefore, CoQ10 may represent a novel therapeutic option for the prevention and treatment of drug-induced liver injury.

Supplementation with Sodium Butyrate Modulates the Composition of the Gut Microbiota and Ameliorates High-Fat Diet-Induced Obesity in Mice.

BACKGROUND: Short-chain fatty acids (SCFAs) have been reported to ameliorate obesity. However, the underlying mechanisms require further investigation. OBJECTIVE: The aim of this study was to determine the role of butyrate, an SCFA, in the regulation of obesity, low-grade chronic inflammation, and alterations of microbiota composition in mice. METHODS: Male C57BL/6J mice, 4-5 wk of age, were divided into 3 groups (n = 8 mice/group): low-fat diet (LFD; 10% energy from fat), high-fat diet (HFD; 45% energy from fat), or high-fat diet plus sodium butyrate (HSB). HSB mice received sodium butyrate at a concentration of 0.1 M in drinking water for 12 wk. Measures of inflammation, obesity, and intestinal integrity were assessed. Serum lipopolysaccharide (LPS) concentrations were measured in the 3 groups. Fecal samples were collected for gut microbiota analysis. RESULTS: In HFD mice, body weight gain and hepatic triglyceride (TG), serum interleukin-6 (IL-6), and serum tumor necrosis factor (TNF)-α levels were 1-4 times higher than those in LFD mice (P < 0.05); they were 34-42% lower in HSB mice compared with HFD mice (P < 0.05). The HFD group had 28%-48% lower mRNA expression of both Tjp1 and Ocln in the ileum and colon compared with levels in LFD or HSB mice (P < 0.05), whereas there was no difference in expression levels between LFD and HSB mice. Furthermore, in HSB mice, serum LPS concentration was 53% lower compared with that in HFD mice but still 23% higher than that in LFD mice (P < 0.05). Results from principal component analysis showed that HSB and LFD mice had a similar gut microbiota structure, which was significantly different from that in HFD mice (P < 0.05). CONCLUSIONS: Sodium butyrate administration beneficially changed HFD-induced gut microbiota composition and improved intestinal barrier, leading to lower serum LPS concentrations. These changes may correspond with improvements in obesity-related lipid accumulation and low-grade chronic inflammation.

CoQ10 Promotes Resolution of Necrosis and Liver Regeneration After Acetaminophen-Induced Liver Injury.

Coenzyme Q10 (CoQ10) which acts as an electron transporter in the mitochondrial respiratory chain has many beneficial effects on liver diseases. In our previous research, CoQ10 has been found to attenuate acetaminophen (APAP)-induced acute liver injury (ALI). However, whether CoQ10 administration is still effective at the late stage of APAP overdose is still unknown. In this study, we aimed to test CoQ10 efficacy at the late stage of APAP overdose. C57BL/6J mice were intraperitoneally treated with APAP to induce liver injury. CoQ10 (5 mg/kg) was given to mice at 16 h after APAP treatment. The results showed that while CoQ10 treatment at 16 h post-APAP overdose had no effects on the expression of ROS generated genes or scavenged genes, it still significantly decreased necrosis of hepatocytes following APAP-induced ALI. Moreover, CoQ10 increased MerTK+ macrophages accumulation in the APAP-overdose liver and inhibition of MerTK signaling partly abrogated the protective role of CoQ10 treatment on the hepatic necrosis. CoQ10 treatment also significantly enhanced hepatocytes proliferation as shown in the increased 5-bromodeoxyuridine incorporation in the APAP-intoxicated mice liver section. In addition, CoQ10 treatment increased hepatic Proliferating Cell Nuclear Antigen (PCNA) and Cyclin D1 expression and promoted activation of the ß-catenin signaling in APAP-overdose mice. To conclude, these data provide evidence that CoQ10 treatment is still effective at the late stage of APAP-induced ALI and promotes resolution of necrosis and liver regeneration following ALI.

Coenzyme Q10 attenuates high-fat diet-induced non-alcoholic fatty liver disease through activation of the AMPK pathway.

Coenzyme Q10 (CoQ10) is a well-known anti-adipogenic factor that possesses the capability to regulate non-alcoholic fatty liver disease (NAFLD). However, the mechanism by which CoQ10 acts on NAFLD is still unclear. In this study, the role of CoQ10 in the prevention of NAFLD was investigated in vivo and in vitro. C57BL/6J mice were fed a normal diet, high-fat diet (HFD) or HFD supplemented with CoQ10 (1800 mg kg-1 HFD) for 24 weeks. HepG2 cells were treated with sodium palmitate for investigating the mechanism of action of CoQ10 on NAFLD. The results showed that CoQ10 alleviated HFD-induced weight gain and NAFLD, accompanied by an anti-hyperlipidaemia effect, by reducing the serum triglycerides, total cholesterol, and low-density lipoprotein cholesterol levels. Importantly, CoQ10 could downregulate the expression of sterol regulatory element-binding protein-1c (SREBP-1c), acetyl-CoA carboxylase (ACC), and fatty acid synthase (FAS), which are related to lipid synthesis, and upregulate the expression of peroxisome proliferator-activated receptors α (PPARα) and carnitine palmitoyltransferase-1 (CPT-1) associated with fatty acid oxidation. Similar to the results from mice, treatment with CoQ10 alleviated sodium palmitate-induced hepatocyte steatosis via the inhibition of lipogenesis and promotion of fatty acid oxidation. However, Compound C, as an AMPK inhibitor, could significantly block the benefits derived from CoQ10 treatment. In conclusion, CoQ10 could serve as an AMPK activator and regulate the hepatic lipid metabolism to inhibit the abnormal accumulation of hepatic lipids and prevent NAFLD progression.

Adropin protects against liver injury in nonalcoholic steatohepatitis via the Nrf2 mediated antioxidant capacity.

Adropin, a secretory signal peptide, has shown beneficial effects on improving glucose homeostasis and dyslipidemia. However, whether this peptide affects nonalcoholic steatohepatitis (NASH) has remained unclear. In this study, the serum adropin levels, liver injury and oxidative stress were measured in diet-induced NASH mice. Adropin knock-out mice and palmitate treated primary hepatic cells were used to investigate the influence of adropin on liver injury. Our results show that serum adropin levels were decreased and negatively correlated with liver injury in NASH mice. Knockout of adropin significantly exacerbated hepatic steatosis, inflammatory responses and fibrosis in mice after either methionine-choline deficient diet (MCD) or western diet (WD) feeding. And the treatment with adropin bioactive peptides ameliorated NASH progression in mice. Adropin alleviated hepatocyte injury by upregulating the expression of Gclc, Gclm, and Gpx1 in a manner dependent on Nrf2 transcriptional activity and by increasing the glutathione (GSH) levels. And adropin significantly increased CBP expression and promoted its binding with Nrf2, which enhanced Nrf2 transcriptional activity. Furthermore, AAV8-mediated overexpression of hepatic Nrf2 expression functionally restored the liver injury induced by adropin-deficiency MCD-fed mice. These findings provide evidence that adropin activates Nrf2 signaling and plays a protective role in liver injury of NASH and therefore might represent a novel target for the prevention and treatment of NASH.

Association of sex hormone-binding globulin with nonalcoholic fatty liver disease in Chinese adults.

BACKGROUND: Sex hormone-binding globulin (SHBG), a glycoprotein synthesized by hepatocytes, has been linked to insulin resistance and hepatic lipid metabolism and is suggested to be associated with nonalcoholic fatty liver disease (NAFLD). This study aimed to investigate the association of SHBG with NAFLD in Chinese adults. METHODS: We conducted a community-based, cross-sectional study in China involving 2912 participants aged 40-75 years old. All participants underwent detection for hepatic fat infiltration by ultrasound in addition to providing complete medical history and undergoing physical and blood biochemical examinations. The association of serum SHBG with the presence of NAFLD was reported by adjusted odds ratio after applying logistic regression models. To further explore the relationship between SHBG and NAFLD, mRNA expression of SHBG and hepatocyte nuclear factor 4-α (HNF4α), as well as intrahepatic triglycerides, were determined from the liver tissues of 32 subjects with different degrees of steatosis. RESULTS: Serum SHBG levels in patients with NAFLD (median, 43.8 nmol/L; interquartile range, 33.4-56.8 nmol/L) were significantly lower than those in non-NAFLD subjects (median, 63.4 nmol/L; interquartile range, 47.6-83.1 nmol/L). Serum SHBG levels were inversely correlated with WHR, trunk fat percentage, glucose, HOMA-IR, TG, UA and DHEAS, and were positively correlated with HDL-C levels (all p <  0.001). Logistic regression analysis indicated that serum SHBG levels were negatively associated with the presence of NAFLD in all subjects, as well as the subgroups stratified by sex, BMI and HOMA-IR (all p <  0.05). In human liver tissues, SHBG and HNF4α mRNA expression decreased along with the elevated grade of hepatic steatosis. Both SHBG and HNF4α mRNA expression levels were negatively correlated with intrahepatic triglycerides. CONCLUSIONS: These results demonstrate that SHBG levels were negatively associated with the presence of NAFLD in middle-aged and elderly Chinese adults.