No abstract

H epatic fibrosis is a major histological finding associated with the progression of chronic liver disease to cirrhosis; it is characterized by increased deposition of components of the extracellular matrix (ECM), in particular fibrillar collagens type I and type III. 1 Hepatic stellate cells (HSC) are currently considered to be one of the major sources of ECM proteins in the liver; expansion of their pool is a key step in the fibrogenic process. 2 Following hepatic injury, HSC develop a myofibroblast-like phenotype, characterized by a reduced content of vitamin A, increased proliferation and migration, enhanced expression of matrix protein, and production of matrix metalloproteinases (MMPs). 3 Evidence from experimental and clinical studies indicates that production of reactive oxygen species (ROS) and lipid peroxidation of cell membranes are often associated with the development of hepatic fibrogenesis and

No abstract

We propose that the variations of the levels of hyaluronic acid in the dermis in aging could account for some of the most striking alterations of the aged skin, including decreased turgidity, less support for microvessels, wrinkling, and altered elasticity.