The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
 
 
 
 
 

Externalization of calpain (calcium-dependent neutral cysteine proteinase) in human arthritic cartilage.

OBJECTIVE: Calcium-dependent neutral cysteine proteinase (calpain) was originally referred to as an intracellular enzyme. However, recently it has come to be considered as an extracellular matrix proteinase, as well having a degrading effect on cartilage proteoglycan. In the present study we sought to determine whether human articular cartilage chondrocytes themselves have the capability to produce and secrete this interesting proteinase. METHODS: Human articular cartilage tissue cultures from osteoarthritic (11 specimens from 7 patients) and rheumatoid arthritic (3 specimens from 2 patients) knee joints were established, and the m-calpain released into the culture medium was concentrated and detected by immunoelectrophoretic blotting. The presence of m-calpain in the arthritic cartilage was also examined by immunohistochemistry before and after culturing. RESULTS: M-calpain was detectable in all of the cartilage tissue culture supernatants (conditioned medium) by western blotting. Positive intracellular immunostaining of m-calpain in chondrocytes was observed in all samples. Furthermore, m-calpain was found to be present in the matrix and on the articular surface of the cartilage in half of the specimens. CONCLUSION: The findings of our experiment suggest that cartilage chondrocytes may actively take part in m-calpain production and that they may have the capacity to release it into the extracellular matrices.[1]

References

  1. Externalization of calpain (calcium-dependent neutral cysteine proteinase) in human arthritic cartilage. Szomor, Z., Shimizu, K., Yamamoto, S., Yasuda, T., Ishikawa, H., Nakamura, T. Clinical and experimental rheumatology. (1999) [Pubmed]
 
WikiGenes - Universities