Centrolobular liver fibrosis in the hypercholesterolemic rabbit

Area of Science:

• Hepatology
• Fibrosis Research
• Cholesterol Metabolism

Background:

• Atheromatous lesion development is often linked to diet.
• Liver fibrosis is a significant pathological outcome in various liver diseases.

Purpose of the Study:

• To investigate the effects of dietary cholesterol on liver fibrosis development in rabbits.
• To characterize the cellular and molecular changes associated with cholesterol-induced liver fibrosis.

Main Methods:

• Rabbits were fed diets with low or high cholesterol supplements.
• Liver fibrosis was assessed using immunohistochemistry for collagen types I, III, IV, fibronectin, alpha-smooth muscle actin, and RAM 11.
• Transmission electron microscopy (TEM) was used to examine cellular changes.
• Northern hybridization was performed to analyze messenger RNA (mRNA) levels of collagen.

Main Results:

• Dietary cholesterol induced moderate to pronounced centrolobular liver fibrosis in rabbits.
• Fibrosis progressed through three stages, involving increased extracellular matrix deposition and cellular infiltration (alpha-SM actin and RAM 11 positive cells).
• TEM revealed activated fat-storing cells with altered morphology and increased collagen mRNA levels were observed.

Conclusions:

• Cholesterol overload is a direct inducer of pericentral liver fibrosis in rabbits.
• Dietary cholesterol activates fat-storing cells, promoting their transition into fibrogenic effector cells.
• The precise mechanism by which hypercholesterolemia triggers this phenotypic transition requires further investigation.