Published in:
Open Access
01-12-2016 | Research
Age-dependent development of liver fibrosis in Glmp
gt/gt
mice
Authors:
Cecilie K. Nesset, Xiang Yi Kong, Markus Damme, Camilla Schjalm, Norbert Roos, Else Marit Løberg, Winnie Eskild
Published in:
Fibrogenesis & Tissue Repair
|
Issue 1/2016
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Abstract
Background
Mice lacking glycosylated lysosomal membrane protein (Glmp
gt/gt
mice) have liver fibrosis as the predominant phenotype due to chronic liver injury. The Glmp
gt/gt
mice grow and reproduce at the same rate as their wild-type siblings. Life expectancy is around 18 months.
Methods
Wild-type and Glmp
gt/gt
mice were studied between 1 week and 18 months of age. Livers were analyzed using histological, immunohistochemical, biochemical, and qPCR analyses.
Results
It was shown that Glmp
gt/gt
mice were not born with liver injury; however, it appeared shortly after birth as indicated by excess collagen expression, deposition of fibrous collagen in the periportal areas, and increased levels of hydroxyproline in Glmp
gt/gt
liver. Liver functional tests indicated a chronic, mild liver injury. Markers of inflammation, fibrosis, apoptosis, and modulation of extracellular matrix increased from an early age, peaking around 4 months of age and followed by attenuation of these signals. To compensate for loss of hepatocytes, the oval cell compartment was activated, with the highest activity of the oval cells detected at 3 months of age, suggesting insufficient hepatocyte proliferation in Glmp
gt/gt
mice around this age. Although constant proliferation of hepatocytes and oval cells maintained adequate hepatic function in Glmp
gt/gt
mice, it also resulted in a higher frequency of liver tumors in older animals.
Conclusions
The Glmp
gt/gt
mouse is proposed as a model for slowly progressing liver fibrosis and possibly as a model for a yet undescribed human lysosomal disorder.