It has been previously reported that small mother against decapentaplegic 3 （Smad3） gene knockout （Smad3^ex8/ex8） mice displays phenotypes similar to human osteoarthritis, as characterized by abnormal hypertrophic...It has been previously reported that small mother against decapentaplegic 3 （Smad3） gene knockout （Smad3^ex8/ex8） mice displays phenotypes similar to human osteoarthritis, as characterized by abnormal hypertrophic differentiation of articular chondrocytes. To further clarify the crucial target genes that mediate transformation growth factor-β （TGF-β）/Smad3 signals on articular chondrocytes differentiation and investigate the underlying molecular mechanism of osteoarthritis, microarrays were used to perform comparative transcriptional profiling in the articular cartilage between Smad3^ex8/ex8and wild-type mice on day five after birth. The gene profding results showed that the activity of bone morphogenetic protein （BMP） and TGF-β/cell division cycle 42 （Cdc42） signaling pathways were enhanced in Smad3^ex8/ex8 chondrocytes. Moreover, there was altered gene expression in growth hormone/insulin-like growth factor 1 （Igfl） axis and fibroblast growth factor （Fgf） signaling pathway. Notably, protein synthesis related genes and electron transport chain related genes were upregulated in Smad3^ex8/ex8 chondrocytes, implying that accelerated protein synthesis and enhanced cellular respiration might contribute to hypertrophic differentiation of articular chondrocytes and the pathogenesis of osteoarthritis.展开更多
Objective： To investigate the effects of mycotoxin moniliformin （MON） on the metabolism of aggrecan and type 11 collagen in human chondrocytes in vitro and the relationship between MON and Kashin-Beck disease （KBD...Objective： To investigate the effects of mycotoxin moniliformin （MON） on the metabolism of aggrecan and type 11 collagen in human chondrocytes in vitro and the relationship between MON and Kashin-Beck disease （KBD）. Methods： Human chondrocytes were isolated and cultured on bone matrix gelatin to form an artificial cartilage model in vitro with or without MON toxin. Cell viability was determined by 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay. The expression of aggrecan and type II collagen in the cartilage was determined using immunocytochemical staining. Results： MON toxin inhibited chondrocyte viability in dose-dependent and time-dependent manners. MON reduced aggrecan and type Ⅱ collagen syntheses in the tissue-engineered cartilage. MON also increased the expression of matrix metalloproteinase-1 （MMP-1）, MMP-13, BC4 epitopes, and CD44 in cartilages. However, the expression of 3B3（-） epitopes in cartilages was inhibited by MON. Selenium partially alleviated the damage of aggrecan induced by MON toxin. Conclusion： MON toxin promoted the catabolism of aggrecan and type II collagen in human chondrocytes.展开更多
基金This work was supported by the National Key Program on Basic Research of China (No. 2006BAI23B01-3)National Natural Scie- nce Foundation of China (No. 30430350, 30500)National High-Tech Research and Development Program (No. 2006AA 02Z168, Z000 6303041231).
文摘It has been previously reported that small mother against decapentaplegic 3 （Smad3） gene knockout （Smad3^ex8/ex8） mice displays phenotypes similar to human osteoarthritis, as characterized by abnormal hypertrophic differentiation of articular chondrocytes. To further clarify the crucial target genes that mediate transformation growth factor-β （TGF-β）/Smad3 signals on articular chondrocytes differentiation and investigate the underlying molecular mechanism of osteoarthritis, microarrays were used to perform comparative transcriptional profiling in the articular cartilage between Smad3^ex8/ex8and wild-type mice on day five after birth. The gene profding results showed that the activity of bone morphogenetic protein （BMP） and TGF-β/cell division cycle 42 （Cdc42） signaling pathways were enhanced in Smad3^ex8/ex8 chondrocytes. Moreover, there was altered gene expression in growth hormone/insulin-like growth factor 1 （Igfl） axis and fibroblast growth factor （Fgf） signaling pathway. Notably, protein synthesis related genes and electron transport chain related genes were upregulated in Smad3^ex8/ex8 chondrocytes, implying that accelerated protein synthesis and enhanced cellular respiration might contribute to hypertrophic differentiation of articular chondrocytes and the pathogenesis of osteoarthritis.
基金Project supported by the National Natural Science Foundation of China (Nos.30872187,30471499,and 30170831)the Ministry of Education of China (No.Key 03152)the Science Foundation of Shaanxi Province of China (No.2004KW-20)
文摘Objective： To investigate the effects of mycotoxin moniliformin （MON） on the metabolism of aggrecan and type 11 collagen in human chondrocytes in vitro and the relationship between MON and Kashin-Beck disease （KBD）. Methods： Human chondrocytes were isolated and cultured on bone matrix gelatin to form an artificial cartilage model in vitro with or without MON toxin. Cell viability was determined by 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay. The expression of aggrecan and type II collagen in the cartilage was determined using immunocytochemical staining. Results： MON toxin inhibited chondrocyte viability in dose-dependent and time-dependent manners. MON reduced aggrecan and type Ⅱ collagen syntheses in the tissue-engineered cartilage. MON also increased the expression of matrix metalloproteinase-1 （MMP-1）, MMP-13, BC4 epitopes, and CD44 in cartilages. However, the expression of 3B3（-） epitopes in cartilages was inhibited by MON. Selenium partially alleviated the damage of aggrecan induced by MON toxin. Conclusion： MON toxin promoted the catabolism of aggrecan and type II collagen in human chondrocytes.
