The painful reality of end-stage liver disease in NASH

C-C motif chemokine CCL11 is a novel regulator and a potential therapeutic target in non-alcoholic fatty liver disease

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) is characterised by accelerated lipid deposition, aberrant inflammation, and excessive extracellular matrix production in the liver. Short of effective intervention, NAFLD can progress to cirrhosis and hepatocellular carcinoma. In the present study we investigated the involvement of the C-C motif ligand 11 (CCL11) in NAFLD pathogenesis.

METHODS

NAFLD was induced by feeding mice with a high-fat high-carbohydrate diet. CCL11 targeting was achieved by genetic deletion or pharmaceutical inhibition. The transcriptome was analysed using RNA-seq.

RESULTS

We report that CCL11 expression was activated at the transcription level by free fatty acids (palmitate) in hepatocytes. CCL11 knockdown attenuated whereas CCL11 treatment directly promoted production of pro-inflammatory/pro-lipogenic mediators in hepatocytes. Compared with wild-type littermates, CCL11 knockout mice displayed an ameliorated phenotype of NAFLD when fed a high-fat high-carbohydrate diet as evidenced by decelerated body weight gain, improved insulin sensitivity, dampened lipid accumulation, reduced immune cell infiltration, and weakened liver fibrosis. RNA-seq revealed that interferon regulatory factor 1 as a mediator of CCL11 induced changes in hepatocytes. Importantly, CCL11 neutralisation or antagonism mitigated NAFLD pathogenesis in mice. Finally, a positive correlation between CCL11 expression and NAFLD parameters was identified in human patients.

CONCLUSIONS

Our data suggest that CCL11 is a novel regulator of NAFLD and can be effectively targeted for NAFLD intervention.

IMPACT AND IMPLICATIONS

Non-alcoholic fatty liver disease (NAFLD) precedes cirrhosis and hepatocellular carcinoma. In this paper we describe the regulatory role of CCL11, a C-C motif ligand chemokine, in NAFLD pathogenesis. Our data provide novel insights and translational potential for NAFLD intervention.

Hospital admission with non-alcoholic fatty liver disease is associated with increased all-cause mortality independent of cardiovascular risk factors

Non-alcoholic fatty liver disease (NAFLD) is common and strongly associated with the metabolic syndrome. Though NAFLD may progress to end-stage liver disease, the top cause of mortality in NAFLD is cardiovascular disease (CVD). Most of the data on liver-related mortality in NAFLD derives from specialist liver centres. It is not clear if the higher reported mortality rates in individuals with non-cirrhotic NAFLD are entirely accounted for by complications of atherosclerosis and diabetes. Therefore, we aimed to describe the CVD burden and mortality in NAFLD when adjusting for metabolic risk factors using a ‘real world’ cohort. We performed a retrospective study of patients followed-up after an admission to non-specialist hospitals with a NAFLD-spectrum diagnosis. Non-cirrhotic NAFLD and NAFLD-cirrhosis patients were defined by ICD-10 codes. Cases were age-/sex-matched with non-NAFLD hospitalised patients. All-cause mortality over 14-years follow-up after discharge was compared between groups using Cox proportional hazard models adjusted for demographics, CVD, and metabolic syndrome components. We identified 1,802 patients with NAFLD-diagnoses: 1,091 with non-cirrhotic NAFLD and 711 with NAFLD-cirrhosis, matched to 24,737 controls. There was an increasing burden of CVD with progression of NAFLD: for congestive heart failure 3.5% control, 4.2% non-cirrhotic NAFLD, 6.6% NAFLD-cirrhosis; and for atrial fibrillation 4.7% control, 5.9% non-cirrhotic NAFLD, 12.1% NAFLD-cirrhosis. Over 14-years follow-up, crude mortality rates were 14.7% control, 13.7% non-cirrhotic NAFLD, and 40.5% NAFLD-cirrhosis. However, after adjusting for demographics, non-cirrhotic NAFLD (HR 1.3 (95% CI 1.1–1.5)) as well as NAFLD-cirrhosis (HR 3.7 (95% CI 3.0–4.5)) patients had higher mortality compared to controls. These differences remained after adjusting for CVD and metabolic syndrome components: non-cirrhotic NAFLD (HR 1.2 (95% CI 1.0–1.4)) and NAFLD-cirrhosis (HR 3.4 (95% CI 2.8–4.2)). In conclusion, from a large non-specialist registry of hospitalised patients, those with non-cirrhotic NAFLD had increased overall mortality compared to controls even after adjusting for CVD.

Polyphenol-rich Trapa quadrispinosa pericarp extract ameliorates high-fat diet induced non-alcoholic fatty liver disease by regulating lipid metabolism and insulin resistance in mice

In China, Trapa quadrispinosa (also called water caltrop) has long been used as a function food and folk medicine to treat diabetes mellitus for years. In the present study, the extract of T. quadrispinosa pericarp (TQPE) which mainly contains hydrolysable tannins was prepared to investigate the potential therapeutic action in non-alcoholic fatty liver disease (NAFLD) mice induced by high fat-diet (HFD). After the administration of TQPE (15, 30 mg/kg/day) for 8 weeks, the increased weight of body and liver were significantly suppressed. TQPE also ameliorated liver lipid deposition and reduced lipids parameters of blood in mice. Moreover, TQPE attenuated oxidative stress and showed a hepatoprotective effect in mice. TQPE was also found to decrease the value of homeostatic model assessment for insulin resistance. In addition, TQPE administration increased the phosphorylation of AMP-activated protein kinase (AMPK) and Acetyl-CoA carboxylase (ACC) and inhibited sterol regulatory element-binding protein (SREBP) in the liver tissue. Meanwhile, TQPE elevated insulin receptor substrate-1 (IRs-1) and protein kinase B (Akt) phosphorylation. These results reflected that, as a nature product, TQPE is a potential agent for suppressing the process of NAFLD via regulation of the AMPK/SREBP/ACC and IRs-1/Akt pathways.