Insulin resistance and necroinflammation drives ductular reaction and epithelial-mesenchymal transition in chronic hepatitis C.
OBJECTIVE
To study the mechanism(s) linking insulin resistance (IR) to hepatic fibrosis and the role of the epithelial component in tissue repair and fibrosis in chronic hepatitis C (CHC).


METHODS
Prospective observational study.


METHODS
Tertiary care academic centre.


METHODS
78 consecutive patients with CHC.


METHODS
IR, calculated by the oral glucose insulin sensitivity during oral glucose tolerance test; necroinflammatory activity and fibrosis, defined according to Ishak's score; steatosis, graded as 0 (<5% of hepatocytes), 1 (5-33%), 2 (33-66%) and 3 (>66%). To evaluate the role of the epithelial component in tissue repair and fibrosis, the expansion of the ductular reaction (DR) was calculated by keratin-7 (CK7) morphometry. Nuclear expression of Snail, downregulation of E-cadherin and expression of fibroblast specific protein-1 (FSP1) and vimentin by CK7-positive cells were used as markers of epithelial-mesenchymal transition in DR elements.


RESULTS
IR, the degree of necroinflammation and expansion of the DR (stratified as reactive ductular cells (RDCs), hepatic progenitor cells and intermediate hepatobiliary cells according to morphological criteria) were all associated with the stage of fibrosis. Nuclear Snail expression, E-cadherin downregulation and vimentin upregulation were observed in RDCs. By dual immunofluorescence for CK7 and FSP1, the number of RDCs undergoing epithelial-mesenchymal transition progressively increased together with the necroinflammatory score. By multivariate analysis, total inflammation and insulin resistance were the only factors significantly predicting the presence of advanced fibrosis (Ishak score ≥3) and the expansion of RDCs.


CONCLUSIONS
This study indicates that IR is associated with the degree of necroinflammatory injury in CHC and contributes to hepatic fibrosis by stimulating the expansion of RDCs that express epithelial-mesenchymal transition markers.
Department of Gastroenterology, Polytechnic University of Marche, Ancona, Italy. g.svegliati@univpm.it
Gianluca
G
Svegliati-Baroni
Graziella
G
Faraci
Luca
L
Fabris
Stefania
S
Saccomanno
Massimiliano
M
Cadamuro
Irene
I
Pierantonelli
Luciano
L
Trozzi
Elisabetta
E
Bugianesi
Maria
M
Guido
Mario
M
Strazzabosco
Antonio
A
Benedetti
Giulio
G
Marchesini
D000328:Adult; D000886:Anthropometry / Q000379:methods; D018450:Disease Progression; D058750:Epithelial-Mesenchymal Transition / Q000502:physiology*; D005260:Female; D005951:Glucose Tolerance Test / Q000379:methods; D019698:Hepatitis C, Chronic / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D008099:Liver / Q000473:pathology*; D008103:Liver Cirrhosis / Q000473:pathology / Q000503:physiopathology / Q000821:virology; D008297:Male; D008875:Middle Aged; D009336:Necrosis / Q000503:physiopathology