The constant amount of type III collagen observed during foetal development changed at birth and increased in mature nuchal ligament to represent approx. 45% of the total collagen.Immunohistochemical studies comparing the localization of type XV collagen in normal human skin and skin tumors with that of type IV collagen.and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima, Japan.We investigated the localization of type XV collagen in normal human skin and skin tumors by immunohistochemical methods using a monoclonal antibody against the recombinant polypeptide of the non-collagenous region of the alpha1 chain of murine type XV collagen. Type XV collagen was localized in the dermo-epidermal, perivascular, and perineural basement membrane zones in normal skin. While this localization appeared to be similar to that of type IV collagen, detailed observation revealed that its localization was distinct in fact from that of type IV collagen which was thin and linear in appearance and was distributed inside organs. Type XV collagen was distributed broadly and zonally outside organs such as vascular and neural tissues. It was expressed at low levels in seborrheic keratosis and not expressed at all in actinic keratosis and squamous cell carcinoma. Melanocytic nevi and malignant melanomas in situ were positive for type XV collagen; melanomas with dermal invasion were negative. These findings suggest that type XV collagen plays a role in the adherence of the basement membrane to surrounding connective tissue and that it may be associated with the tumorigenesis of keratinocytes and melanocytes.Influence of fulvic acid on the collagen secretion of bovine chondrocytes in High concentrations of fulvic acid and selenium deficiency in drinking water are the main causative factors of Kashin-Beck disease, an endemic degenerative chronic osteoarticular disorder found in China. The influence of fulvic acid on collagen secretion was investigated in articular chondrocyte cultures from bovine interphalangeal joints. Collagen secretion in 7-day-old chondrocyte monolayers was determined by measuring [3H]-proline incorporation into collagen macromolecules after a 24-h application in cultured supernatants. Additionally, collagen secretion was measured with a collagen assay based on a dye-binding method of soluble collagens. Both methods showed a dose-dependent increase of collagen secretion after treatment with fulvic acid. The collagen was identified by immunoblotting and immunocytochemistry as type II collagen. Fulvic acid also induced H2O2 production in cartilage cells. After the ordinary squalane cleanser -incubation with catalase and fulvic acid, the cells secreted the same amount of H2O2 or collagen as the non-treated controls, indicating an influence of H2O2 on collagen secretion. Chondrocytes were then treated directly with H2O2. This led to increased collagen secretion showing a positive correlation with the concentration of H2O2 up to 1 pM H2O2. Larger amounts of H2O2 decreased collagen secretion. Effects of reactive oxygen species, such as lipid peroxidation or lactate dehydrogenase (LDH) release from damaged cells, were not inducable by fulvic acid (<10 ppm). squalene demonstrate a fulvic-acid-induced stimulation of collagen secretion into the supernatant by articular chondrocytes via physiological amounts of Cloning of mouse type XV collagen sequences and mapping of the corresponding gene to 4B1-3. Comparison of mouse and human alpha 1 (XV) collagen sequences indicates divergence in the number of small collagenous domains.We report on full-length mouse type XV collagen cDNAs that encode a 1367-residue alpha 1(XV) chain. The amino acid sequences of the mouse and previously characterized human alpha 1(XV) chains exhibit an overall identity of 72%. The highest homology between these chains and to the structurally related type XVIII collagen is observed in their C-terminal noncollagenous domains. Although the mouse and human alpha 1(XV) chains are highly homologous and similar in their overall domain structure, the mouse chain contains only seven collagenous domains, whereas the human chain contains nine. Northern analysis of several mouse tissues indicated strong hybridization in the case of heart and skeletal muscle RNAs and moderate signals with kidney, lung, and testis RNAs. Analysis of type XV collagen mRNA levels at different stages of mouse embryonic development indicated a marked increase in the level between 11 and 15 days of development, which coincides with pronounced development of the muscles, heart, and vascular system in the mouse embryo. The mouse gene for type XV collagen was mapped by fluorescence in situ hybridization to chromosome 4, band B1-3. This result indicates that the mouse type XV collagen gene and its human counterpart are located in the chromosomal segments with conserved syntenies.The role of matrix metalloprotease (MMP) to the autolysis of sea cucumber BACKGROUND: Sea cucumber (Stichopus japonicus) is easy to autolysis in response to a variety of environmental and mechanical factors. In the current study, collagen fibres were extracted from fresh sea cucumber body wall and then incubated with endogenous matrix metalloprotease (MMP) of sea cucumber.
the ordinary squalane cleanser|squalene
