Comparable response of ccn1 with ccn2 genes upon arthritis: An in vitro evaluation with a human chondrocytic cell line stimulated by a set of cytokines

Background: The chondrosarcoma-derived HCS-2/8 has been known to be an excellent model of human articular chondrocytes. By mimicking the arthritic conditions through the treatment of HCS-2/8 cells with cytokines, we estimated the gene expression response of ccn1 and ccn2 during the course of joint inflammation in vitro. Results: In order to mimic the initiation of inflammation, HCS-2/8 cells were treated with tumor necrosis factor (TNF)-α. To induce pro-inflammatory or reparative responses, TGF-β was employed. Effects of an anti-inflammatory glucocorticoid were also evaluated. After stimulation, expression levels of ccn1 and ccn2 were quantitatively analyzed. Surprisingly, not only ccn2, but also ccn1 expression was repressed upon TNF-α stimulation, whereas both mRNAs were uniformly induced by transforming growth factor (TGF)-β and a glucocorticoid. Conclusion: These results describing the same response during the course of inflammation suggest similar and co-operative roles of these 2 ccn family members in the course of arthritis.</p

Dimethyl sulfoxide-respiring bacteria in Suribati Ike, a hypersaline lake, in Antarctica and the marine environment

Dimethyl sulfoxide (DMSO) occurs worldwide, especially in marine environments as well as in lakes and rainwater. DMSO respiration by bacteria is assumed to play an important role in the sulfur cycle in Antarctica and on earth. We first studied whether DMSO-respiring bacteria existed in Antarctica. Eight strains were isolated that grew by DMSO respiration under anaerobic conditions from water of the halocline in a meromictic lake, Suribati Ike, near Syowa Station in Antarctica. All of them were related to known species belonging to the genus Marinobacter based on 16S rRNA gene sequences. Using a clone library analysis of 16S rRNA gene sequences, 38 of total 48 clones from water of the halocline were identified as Marinobacter. Studies on the various anaerobic respiration capabilities by bacteria in the halocline water found only DMSO respiration. Studies on bacteria with anaerobic respiration abilities in seawater from the Pacific Ocean and Seto Inland Sea, showed that either DMSO-respiring or nitrate-respiring bacteria were present and that all of isolates capable of DMSO respiration were closely related to Vibrio species