Abstract
Transforming growth factor beta1 (TGFbeta1) is an important immunosuppressive cytokine. Defects in its production by lymphocytes and the failure of TGFbeta1 to regulate immunological functions have been described in SLE. Expression of TGFbeta1 and the related signaling pathway was studied in the peripheral lymphocytes of SLE patients. The total plasma TGFbeta1 level in active and inactive SLE patients compared to healthy controls was also measured. TGFbeta1 and all downstream signaling elements were expressed in normal cells. However, in more than 50% of SLE patients the isolated T cell population showed no TGFbeta1 mRNA expression and at least one member of the TGFbeta1 pathway was also missing (TGFbeta-RI, Smad2 and Smad3) in more than half of the patients. Total plasma TGFbeta1 level was increased in both active and inactive SLE groups compared to normal controls (p< 0.05). These data raise questions about the availability of TGFbeta1 signaling in lymphocytes in SLE patients, however, the elevated total plasma TGFbeta1 level suggests that the failure of TGFbeta1 effects is not the consequence of low level of this cytokine in SLE.
Publication types
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Comparative Study
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Research Support, Non-U.S. Gov't
MeSH terms
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Adolescent
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Adult
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Case-Control Studies
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Enzyme-Linked Immunosorbent Assay
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Female
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Humans
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Lupus Erythematosus, Systemic / genetics*
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Lupus Erythematosus, Systemic / metabolism
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Lupus Erythematosus, Systemic / pathology
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Lymphocytes / metabolism*
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Lymphocytes / pathology
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Male
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Middle Aged
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Protein Serine-Threonine Kinases / genetics*
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Protein Serine-Threonine Kinases / metabolism
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RNA, Messenger / genetics
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RNA, Messenger / metabolism
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Receptor, Transforming Growth Factor-beta Type I
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Receptors, Transforming Growth Factor beta / genetics*
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Receptors, Transforming Growth Factor beta / metabolism
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Reverse Transcriptase Polymerase Chain Reaction
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Signal Transduction
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Smad2 Protein / genetics*
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Smad2 Protein / metabolism
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Smad3 Protein / genetics*
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Smad3 Protein / metabolism
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Transforming Growth Factor beta1 / genetics*
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Transforming Growth Factor beta1 / metabolism
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Young Adult
Substances
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RNA, Messenger
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Receptors, Transforming Growth Factor beta
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SMAD2 protein, human
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SMAD3 protein, human
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Smad2 Protein
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Smad3 Protein
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Transforming Growth Factor beta1
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Protein Serine-Threonine Kinases
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Receptor, Transforming Growth Factor-beta Type I