Matrix metalloproteinase-9-mediated type III collagen degradation as a novel serological biochemical marker for liver fibrogenesis.
BACKGROUND
During fibrogenesis in the liver, in which excessive remodelling of the extracellular matrix (ECM) occurs, both the quantity of type III collagen (CO3) and levels of matrix metalloproteinases (MMPs), including MMP-9, increase significantly. MMPs play major roles in ECM remodelling, via their activity in the proteolytic degradation of extracellular macromolecules such as collagens, resulting in the generation of specific cleavage fragments. These neo-epitopes may be used as markers of fibrosis.


OBJECTIVE
The current study investigated whether a novel enzyme-linked immunosorbent assay (ELISA) assay specifically measuring an MMP-9-cleaved sequence of type III collagen located at position 610 (CO3-610C) may be used as a marker of liver fibrosis.


METHODS
Bile duct ligation (BDL) was performed in 20 rats, with sham operations performed on another 20 rats. Serum levels of the neo-epitope CO3-610C (MMP-mediated type III collagen degradation) were determined with an ELISA at 14 and 28 days post-surgery. Liver fibrosis was evaluated by quantitative digital image analysis of Sirius red-stained formalin-fixed and paraffin-embedded sections. Western blot and densitometry were performed to confirm the CO3-610C ELISA data.


RESULTS
CO3-610C levels in serum increased significantly in BDL rats compared with those undergoing sham operations (% increase: 14 days=153%, P<0.0001; 28 days=134%, P=0.0014). This increase was confirmed by Western blot and densitometry of the identified bands. The CO3-610C levels correlated to liver fibrosis (R(2) =0.23 and P=0.01), as evaluated by quantitative digital histology.


CONCLUSIONS
The data suggest that MMP-9-mediated CO3 turnover is a central event in the pathogenesis of fibrosis, and that the neo-epitope generated may be a novel biochemical marker.
Veidal
Sanne S
SS
Nordic Bioscience, Herlev, Denmark.
Vassiliadis
Efstathios
E
Barascuk
Natasha
N
Zhang
Chen
C
Segovia-Silvestre
Toni
T
Klickstein
Lloyd
L
Larsen
Martin R
MR
Qvist
Per
P
Christiansen
Claus
C
Vainer
Ben
B
Karsdal
Morten A
MA
D000818:Animals; D001652:Bile Ducts / Q000601:surgery; D015415:Biomarkers / Q000097:blood; D024061:Collagen Type III / Q000097:blood* / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D000939:Epitopes / Q000097:blood*; D005109:Extracellular Matrix / Q000201:enzymology / Q000473:pathology; D005260:Female; D015870:Gene Expression; D007091:Image Processing, Computer-Assisted; D008026:Ligation / Q000009:adverse effects; D008099:Liver / Q000378:metabolism / Q000473:pathology; D008106:Liver Cirrhosis, Experimental / Q000097:blood* / Q000473:pathology; D020780:Matrix Metalloproteinase 9 / Q000097:blood*; D051381:Rats; D017207:Rats, Sprague-Dawley
D015415:Biomarkers; D024061:Collagen Type III; D000939:Epitopes; D020780:Matrix Metalloproteinase 9