Serum-inducible protein (IP)-10 is a disease progression-related marker for non-alcoholic fatty liver disease.
BACKGROUND
The molecular pathogenesis of non-alcoholic steatohepatitis (NASH) is not well defined. The objective of the present study was to identify disease progression-related cytokines and investigate the molecular pathogenesis of such changes in NASH.


METHODS
A study population of 20 non-alcoholic fatty liver (NAFL) and 59 NASH patients diagnosed by liver biopsy and 15 healthy volunteers was recruited. The serum pro- and anti-inflammatory cytokines were measured by a multiple enzyme-linked immunosorbent assay. The hepatic mRNA expressions of cytokines were measured by real-time PCR. A monocyte cell line was stimulated with Toll-like receptor (TLR) ligand under a high glucose and insulin condition, and cellular cytokine mRNA expression was quantified.


RESULTS
One group of cytokines was higher in NAFL and NASH than in controls, while another group was higher in NASH than in NAFL and controls. The NASH-specific second group included interleukin (IL)-15 and interferon-γ-inducible protein (IP)-10. In particular, IP-10 was higher in NAFL than in controls and higher in NASH than in NAFL and controls. The sensitivity to diagnose NASH was 90%, with specificity of 50%. Insulin resistance reflecting a high glucose and insulin condition resulted in higher IP-10 mRNA expression in the monocyte cell line only with concomitant TLR-2 stimulation.


CONCLUSIONS
IP-10 is a sensitive marker of the need for liver biopsy. Insulin resistance with bacteria-related TLR-2 stimulation might induce IP-10 production from monocytes. Insulin resistance and intestinal barrier function should be intensively controlled to prevent progression from NAFL to NASH.
Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
Nozomu
N
Wada
Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan. akitaka@md.okayama-u.ac.jp.
Akinobu
A
Takaki
Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
Fusao
F
Ikeda
Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
Tetsuya
T
Yasunaka
Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
Masahiro
M
Onji
Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
Kazuhiro
K
Nouso
Department of Medical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
Atsuko
A
Nakatsuka
Department of Medical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
Jun
J
Wada
Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
Kazuko
K
Koike
Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
Koji
K
Miyahara
Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
Hidenori
H
Shiraha
Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
Kazuhide
K
Yamamoto
Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
Hiroyuki
H
Okada
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002460:Cell Line; D054357:Chemokine CXCL10 / Q000097:blood* / Q000235:genetics*; D018450:Disease Progression; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease / Q000097:blood / Q000235:genetics / Q000473:pathology*
D015415:Biomarkers; C114753:CXCL10 protein, human; D054357:Chemokine CXCL10
Insulin resistance, interferon-γ-inducible protein-10; Non-alcoholic fatty liver disease; Non-alcoholic steatohepatitis