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Full-Text Articles in Medicine and Health Sciences
Modulation Of Tgf-Beta Signaling By Proinflammatory Cytokines In Articular Chondrocytes., Jorge A. Roman-Blas, David G. Stokes, Sergio A. Jimenez
Modulation Of Tgf-Beta Signaling By Proinflammatory Cytokines In Articular Chondrocytes., Jorge A. Roman-Blas, David G. Stokes, Sergio A. Jimenez
Department of Medicine Faculty Papers
OBJECTIVE: The normal structure and function of articular cartilage are the result of a precisely balanced interaction between anabolic and catabolic processes. The transforming growth factor-beta (TGF-beta) family of growth factors generally exerts an anabolic or repair response; in contrast, proinflammatory cytokines such as interleukin 1 beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) exert a strong catabolic effect. Recent evidence has shown that IL-1beta, and TNF-alpha, and the TGF-beta signaling pathways share an antagonistic relationship. The aim of this study was to determine whether the modulation of the response of articular chondrocytes to TGF-beta by IL-1beta or TNF-alpha signaling pathways …
B-Myb Acts As A Repressor Of Human Col1a1 Collagen Gene Expression By Interacting With Sp1 And Cbf Factors In Scleroderma Fibroblasts, Lucia Cicchillitti, Sergio A. Jimenez, Arturo Sala, Biaggio Saitta
B-Myb Acts As A Repressor Of Human Col1a1 Collagen Gene Expression By Interacting With Sp1 And Cbf Factors In Scleroderma Fibroblasts, Lucia Cicchillitti, Sergio A. Jimenez, Arturo Sala, Biaggio Saitta
Selected Works of Sergio Jiménez, MD, MACR
We investigated the role of B-Myb, a cell-cycle-regulated transcription factor, in the expression of the alpha1 (I) pro-collagen gene (COL1A1) in scleroderma fibroblasts. Scleroderma or SSc (systemic sclerosis) is a fibrotic disease characterized by excessive production of extracellular matrix components, especially type I collagen. Northern-blot analysis showed an inverse relationship between COL1A1 mRNA expression and that of B-Myb during exponential cell growth and during quiescence in human SSc fibroblasts. Overexpression of B-Myb in SSc fibroblasts was correlated with decreased COL1A1 mRNA expression. Transient transfections localized the down-regulatory effect of B-Myb to a region containing the proximal 174 bp of the …
Regulation Of Human Col9a1 Gene Expression. Activation Of The Proximal Promoter Region By Sox9., Ping Zhang, Sergio A. Jimenez, David G Stokes
Regulation Of Human Col9a1 Gene Expression. Activation Of The Proximal Promoter Region By Sox9., Ping Zhang, Sergio A. Jimenez, David G Stokes
Department of Medicine Faculty Papers
The COL9A1 gene contains two promoter regions, one driving expression of a long alpha1(IX) chain in cartilage (upstream) and one driving expression of a shorter chain in the cornea and vitreous (downstream). To determine how the chondrocyte-specific expression of the COL9A1 gene is regulated, we have begun to characterize the upstream chondrocyte-specific promoter region of the human COL9A1 gene. Transient-transfection analyses performed in rat chondrosarcoma (RCS) cells, human chondrosarcoma (HTB) cells, and NIH/3T3 cells showed that the COL9A1 promoter was active in RCS cells but not HTB or NIH/3T3 cells. Inclusion of the first intron had no effect on promoter …
Regulation Of Type-Ii Collagen Gene Expression During Human Chondrocyte De-Differentiation And Recovery Of Chondrocyte-Specific Phenotype In Culture Involves Sry-Type High-Mobility-Group Box (Sox) Transcription Factors, David G. Stokes, Gang Liu, Rita Dharmavaram, David Hawkins, Sonsoles Piera-Velazquez, Sergio A. Jimenez
Regulation Of Type-Ii Collagen Gene Expression During Human Chondrocyte De-Differentiation And Recovery Of Chondrocyte-Specific Phenotype In Culture Involves Sry-Type High-Mobility-Group Box (Sox) Transcription Factors, David G. Stokes, Gang Liu, Rita Dharmavaram, David Hawkins, Sonsoles Piera-Velazquez, Sergio A. Jimenez
Selected Works of Sergio Jiménez, MD, MACR
During ex vivo growth as monolayer cultures, chondrocytes proliferate and undergo a process of de-differentiation. This process involves a change in morphology and a change from expression of chondrocyte-specific genes to that of genes that are normally expressed in fibroblasts. Transfer of the monolayer chondrocyte culture to three-dimensional culture systems induces the cells to re-acquire a chondrocyte-specific phenotype and produce a cartilaginous-like tissue in vitro. We investigated mechanisms involved in the control of the de-differentiation and re-differentiation process in vitro. De-differentiated chondrocytes re-acquired their chondrocyte-specific phenotype when cultured on poly-(2-hydroxyethyl methacrylate) (polyHEMA) as assayed by morphology, reverse transcriptase PCR of …