Reduced circulating levels of sTWEAK are associated with NAFLD and may affect hepatocyte triglyceride accumulation.
Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome and is strongly associated with obesity, dyslipidaemia and altered glucose regulation. Previous data demonstrated that low circulating levels of tumour necrosis factor weak inducer of apoptosis (sTWEAK) were associated with obesity, diabetes and insulin resistance, all traits associated with an increased risk of NALFD. Circulating sTWEAK levels are expected to be reduced in the presence of NAFLD.



We aimed to explore the relationship between NAFLD and circulating sTWEAK levels in obese patients, and to evaluate the effect of sTWEAK on hepatocyte triglyceride accumulation.Design setting and patients:This is an observational case-control study performed in n=112 severely obese patients evaluated for NAFLD by abdominal ultrasound and n=32 non-obese patients without steatosis. Serum sTWEAK concentrations were measured by ELISA. Multivariable analyses were performed to determine the independent predictors of NAFLD. We analysed TWEAK and Fn14 protein expression in liver biopsies by western blotting and immunohistochemistry. An immortalized primary human hepatocyte cell line (HHL) was used to evaluate the effect of sTWEAK on triglyceride accumulation.



We observed a reduction in serum circulating sTWEAK concentrations with the presence of liver steatosis. On multivariable analysis, lower sTWEAK concentrations were independently associated with the presence of NAFLD (odds ratio (OR)=0.023; 95% confidence interval: 0.001-0.579; P<0.022). In human hepatocytes, sTWEAK administration reduced fat accumulation as demonstrated by the reduction in palmitic acid-induced accumulation of triglyceride and the decreased expression of cluster of differentiation 36 (CD36) and perilipin 1 and 2 (PLIN1 and PLIN2) genes.



Decreased sTWEAK concentrations are independently associated with the presence of NAFLD. This is concordant with the observation that TWEAK reduces lipid accumulation in human liver cells.
Joan XXIII University Hospital, IISPV, Tarragona, Spain.|Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas (CIBERDEM), Madrid, Spain.
J
J
Lozano-Bartolomé
Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas (CIBERDEM), Madrid, Spain.|Department of Endocrinology and Nutrition, Hospital del Mar Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), Barcelona, Spain.
G
G
Llauradó
Department of Diabetes, Endocrinology and Nutrition, IdIBGi, CIBERObn, Girona, Spain.
M M
MM
Rodriguez
Department of Diabetes, Endocrinology and Nutrition, IdIBGi, CIBERObn, Girona, Spain.
J M
JM
Fernandez-Real
Pathology Department, Joan XXIII University Hospital, Tarragona, Spain.
J F
JF
Garcia-Fontgivell
Department of Radiology (IDI), Girona Biomedical Research Institute (IDIBGI), Hospital Universitari de Girona Dr Josep Trueta, Girona, Spain.
J
J
Puig
Joan XXIII University Hospital, IISPV, Tarragona, Spain.|Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas (CIBERDEM), Madrid, Spain.
E
E
Maymó-Masip
Joan XXIII University Hospital, IISPV, Tarragona, Spain.|Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas (CIBERDEM), Madrid, Spain.
J
J
Vendrell
Joan XXIII University Hospital, IISPV, Tarragona, Spain.|Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas (CIBERDEM), Madrid, Spain.
M R
MR
Chacón
D000328:Adult; D015992:Body Mass Index; D016022:Case-Control Studies; D000074049:Cytokine TWEAK / Q000097:blood*; D005260:Female; D022781:Hepatocytes / Q000378:metabolism*; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D008099:Liver / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease / Q000097:blood* / Q000150:complications / Q000503:physiopathology; D009765:Obesity / Q000097:blood* / Q000150:complications / Q000503:physiopathology; D014280:Triglycerides / Q000097:blood*
D000074049:Cytokine TWEAK; C109743:TNFSF12 protein, human; D014280:Triglycerides