24 research outputs found
Intra-articular supplementation with recombinant human GDF5 arrests disease progression and stimulates cartilage regeneration in the rat medial meniscus transection (MMT) model of osteoarthritis
Genome-wide expression profiling establishes novel modulatory roles of vitamin C in THP-1 human monocytic cell line
Intra-articular supplementation with recombinant human GDF5 arrests disease progression and stimulates cartilage regeneration in the rat medial meniscus transection (MMT) model of osteoarthritis
Partial characterization of a unique 84-kDa polypeptide stimulated by ascorbic acid in skin fibroblasts
Intra-articular therapy with recombinant human GDF5 arrests disease progression and stimulates cartilage repair in the rat medial meniscus transection (MMT) model of osteoarthritis
Over-the-counter anti-ageing topical agents and their ability to protect and repair photoaged skin
Decreased Collagen Production in Chronologically Aged Skin : Roles of Age-Dependent Alteration in Fibroblast Function and Defective Mechanical Stimulation
Reduced synthesis of collagen types I and III is characteristic of chronologically aged skin. The present report provides evidence that both cellular fibroblast aging and defective mechanical stimulation in the aged tissue contribute to reduced collagen synthesis. The reduction in collagen synthesis due to fibroblast aging was demonstrated by a lower in vitro production of type I procollagen by dermal fibroblasts isolated from skin of young (18 to 29 years) versus old (80+ years) individuals (82 ± 16 versus 56 ± 8 ng/ml; P < 0.05). A reduction in mechanical stimulation in chronologically aged skin was inferred from morphological, ultrastructural, and fluorescence microscopic studies. These studies, comparing dermal sections from young and old individuals, demonstrated a greater percentage of the cell surface attached to collagen fibers (78 ± 6 versus 58 ± 8%; P < 0.01) and more extensive cell spreading (1.0 ± 0.3 vs. 0.5 ± 0.3; P < 0.05) in young skin compared with old skin. These features are consistent with a lower level of mechanical stimulation on the cells in old versus young skin. Based on the findings presented here, we conclude that reduced collagen synthesis in chronologically aged skin reflects at least two different underlying mechanisms: cellular fibroblast aging and a lower level of mechanical stimulation