Liver fibrosis in elderly cadavers: localization of collagen types I, III, and IV, α-smooth muscle actin, and elastic fibers.
We have shown a high prevalence of liver fibrosis in elderly cadavers with diverse causes of death by Sirius red stain; however, the various collagen types in these samples have yet to be evaluated. To further characterize the histopathology of the fibrotic lesions in the livers of these elderly cadavers, this study used immunohistochemistry and histochemistry to identify the principal collagens produced in liver fibrosis, fibrogenic cells and elastic fibers. Collagen I and III immunoreactions were found to colocalize in collagen fibers of fibrotic central veins, perisinusoidal fibrotic foci, portal tract stroma, and fibrous septa. α-Smooth muscle actin-expressing perisinusoidal hepatic stellate cells (HSCs), as well as perivenular, portal, and septal myofibroblasts, were closely associated with collagen fibers, reflecting their fibrogenic functions. HSCs and myofibroblasts were also noted to express collagen IV, which may contribute to production of basal lamina-like structures. In fibrotic livers, the sinusoidal lining showed variable immunostaining for collagen IV. Collagen IV immunostaining revealed vascular proliferation and atypical ductular reaction at the portal-septal parenchymal borders, as well as capillary-like vessels in the lobular parenchyma. While elastic fibers were absent in the space of Disse, they were found to codistribute with collagens in portal tracts, fibrous septa and central veins. Our combined assessment of collagen types, HSCs, myofibroblasts, and elastic fibers is significant in understanding the histopathology of fibrosis in the aging liver.
Department of Medical Education, Center for Anatomy and Functional Morphology, Mount Sinai School of Medicine, New York, New York, USA. ki.mak@mssm.edu
Ki M
KM
Mak
Edward
E
Chu
K H Vincent
KH
Lau
Allison J
AJ
Kwong
D000199:Actins / Q000378:metabolism*; D000369:Aged, 80 and over; D015415:Biomarkers / Q000378:metabolism; D002102:Cadaver; D002478:Cells, Cultured; D024042:Collagen Type I / Q000378:metabolism*; D024061:Collagen Type III / Q000378:metabolism*; D024141:Collagen Type IV / Q000378:metabolism*; D004547:Elastic Tissue / Q000378:metabolism / Q000473:pathology*; D055166:Hepatic Stellate Cells / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007124:Immunoenzyme Techniques; D008103:Liver Cirrhosis / Q000378:metabolism / Q000473:pathology*; D058628:Myofibroblasts / Q000378:metabolism / Q000473:pathology
D000199:Actins; D015415:Biomarkers; D024042:Collagen Type I; D024061:Collagen Type III; D024141:Collagen Type IV