Medicine and Health Sciences Commons^™

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 …

Role Of Protein Kinase C-Delta In The Regulation Of Collagen Gene Expression In Scleroderma Fibroblasts, Sergio A. Jimenez, Svetlana Gaidarova, Biagio Saitta, Nora Sandorfi, David J. Herrich, Joan C. Rosenbloom, Umberto Kucich, William R. Abrams, Joel Rosenbloom

Selected Works of Sergio Jiménez, MD, MACR

Working with cultured dermal fibroblasts derived from control individuals and patients with systemic sclerosis (SSc), we have examined the effects of protein kinase C-delta (PKC-delta) on type I collagen biosynthesis and steady-state levels of COL1A1 and COL3A1 mRNAs. Rottlerin, a specific inhibitor of PKC-delta, exerted a powerful, dose-dependent inhibition of type I and type III collagen gene expression in normal and SSc cells. Optimal rottlerin concentrations caused a 70-90% inhibition of type I collagen production, a >80% reduction in COL1A1 mRNA, and a >70% reduction in COL3A1 mRNA in both cell types. In vitro nuclear transcription assays and transient transfections …

Identification Of Fetal Dna And Cells In Skin Lesions From Women With Systemic Sclerosis, Carol M. Artlett, J. Bruce Smith, Sergio A. Jimenez

Selected Works of Sergio Jiménez, MD, MACR

BACKGROUND: Systemic sclerosis is a disease of unknown origin which often occurs in women after their childbearing years. It has many clinical and histopathological similarities to chronic graft-versus-host disease. Recent studies indicate that fetal stem cells can survive in the maternal circulation for many years post partum. This finding suggests that fetal cells persisting in the maternal circulation or tissues could be involved in the pathogenesis of systemic sclerosis by initiating a graft-versus-host reaction.

METHODS: We used the polymerase chain reaction (PCR) to identify Y-chromosome sequences in DNA extracted from peripheral-blood cells and skin lesions from women with systemic sclerosis …

Stimulation Of Alpha 1(I) Procollagen Gene Expression In Nih-3t3 Cells By The Human T Cell Leukemia Virus Type 1 (Htlv-1) Tax Gene., E. Munoz, D. Suri, S. Amini, K. Khalili, Sergio A. Jimenez

Selected Works of Sergio Jiménez, MD, MACR

The mechanisms that regulate the expression of genes encoding extracellular matrix proteins in fibroblasts and other mesenchymal cells have remained elusive. Studies from several laboratories have indicated that Tax, a trans-regulatory protein from the human T cell leukemia virus type I not only augments viral gene expression but also triggers the expression of various cellular genes. Here, we examined the hypothesis that the expression of collagen genes may also be modulated by Tax. NIH-3T3 cells were simultaneously transfected with a Tax expressor plasmid and a chimeric construct containing regulatory sequences (-804 to +42 bp) of the alpha 1(I) procollagen gene …