The stellate cell system (vitamin A-storing cell system).

Area of Science:

• Hepatology
• Cell Biology
• Histology

Background:

• Hepatic stellate cells (HSCs), also known as Ito cells, were first discovered in 1876 and rediscovered in 1971.
• These cells reside in the liver and are the primary storage site for vitamin A in the body.
• Extrahepatic stellate cells (EHSCs) also exist in organs like the pancreas, lung, and kidney.

Purpose of the Study:

• This review summarizes and discusses past, present, and future research on hepatic stellate cells.
• It aims to provide a comprehensive overview of HSC biology and their role in liver pathology.
• The review highlights the evolution of research methodologies and their impact on HSC studies.

Main Methods:

• Historical review of scientific literature.
• Analysis of histological techniques, including gold chloride staining and electron microscopy.
• Discussion of cell isolation, culture, and molecular/cellular biological techniques.

Main Results:

• HSCs store 50-80% of the body's vitamin A in lipid droplets.
• In liver fibrosis, HSCs lose vitamin A and activate to myofibroblast-like cells.
• Activated HSCs excessively synthesize extracellular matrix components like collagen, contributing to liver scarring.

Conclusions:

• Hepatic stellate cells play a dual role in vitamin A homeostasis and liver fibrogenesis.
• Understanding HSC activation is critical for developing therapies for liver fibrosis.
• Continued research, aided by advanced techniques, will further elucidate HSC functions and therapeutic targets.