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In vivo hyperexpression of transforming growth factor-β1 in humans: Stimulation by cyclosporine
ELSEVIER
In Vivo Hyperexpression of Transforming Growth Factor-P, in Humans: Stimulation by Cyclosporine G.-T. Shin, A. Khanna, V.K. Sharma, R. Ding, S. Azizlerli,
S
TUDIES on the mechanisms of action of cyclosporine (CyA) have shown that the drug-cyclophilin complex binds and inhibits calcineurin, a calcium and calmodulindependent serine-threonine phosphatase. This inactivation prevents dephosphorylation of nuclear factor of activated T cells (NF-AT), the nuclear import of NF-AT, and the formation of a transcriptionally active NF-AT complex. The net consequence, inhibition of IL-2 gene expression at the transcriptional level, is considered to be the primary mechanism for the immunosuppressive activity of CyA.l We identified, for the first time, that CyA, in striking contrast to its inhibitory activity on IL-2 gene transcription, stimulates transforming growth factor-p, (TGF-0,) expression.2 We also found that CyA can inhibit new DNA synthesis in mammalian cells via a TGF-&-dependent mechanism.3 TGF-/3, is a potent immunosuppressant and a fibrogenic cytokine.495 Our previous studies demonstrating a stimulatory effect of CyA on TGF-/3, expression were all in vitro studies.2,3 We have determined herein whether CyA induces hyperexpression of TGF-/3, in vivo in humans. PATIENTS AND METHODS The in vivo effect of CyA on TGF-P, expression was investigated in living-donor renal allograft recipients preconditioned with a regimen of oral CyA, 6 mdkg per day, for 7 days’ pretransplantation. The patients did not receive any other immunosuppressive drug during CyA therapy. Sera (n = 18 samples), isolated from the venous blood obtained prior to and after completion of CyA therapy (and prior to transplantation), were tested for TGF-P, using a sandwich ELISA as described.3 RESULTS
All nine patients showed an increase in TGF-& protein concentration following CyA therapy; the mean 2 SEM of TGF-/3, protein concentration increased from 174 t 61
0041-1315/97/$17.00 PII SOO41-1345(96)00094-2
B. Li, and M. Suthanthiran
pg/mL to 354 2 65 pg/mL (P = .00.5 by paired t test) following CyA monotherapy. DISCUSSION
Our first demonstration of CyA’s stimulatory activity in vivo in humans lends credence to the hypothesis that CyA functions as an immunosuppressant not only by inhibiting the production of proinflammatory cytokines (eg, IL-2) but also by promoting the expression of TGF-P,, a potent immunosuppressive cytokine. The stimulatory activity of CyA also advances a mechanism for the interstitial fibrosis observed with the clinical use of CyA, since TGF-P, is a fibrogenic cytokine. The contribution of CyA-induced hyperexpression of TGF-P, to in vivo immunosuppression facilitating organ graft survival, and to renal fibrosis, needs to be explored in experiments where TGF-& expression is specifically downregulated (eg, TGF-&-specific antisense oligonucleotides). REFERENCES 1. Suthanthiran M, Morris RE, Strom TB: Am J Kidney Dis 1996:28, 1.59 2. Li B, Sehajpal P, Khanna A, et al: J Exp Med 1991:174, 1259 3. Khanna AK, Li B, Stenzel KH, et al: Transplantation 199457, 577 4. Roberts AB, Sporn MB: Growth Factors 8:1, 1993 5. Shull MM, Ormsby I, Kier AB, et al: Nature 359:693, 1992
From the Rogosin Institute, New York. This work was supported in part by an award from the National Institutes of Health (A126932). Address reprint requests to G.-T. Shin, the Rogosin Institute, Division of Nephrology, Department of Transplantation Medicine & Extracorporeal Therapy, New York Hospital-Cornell Medical Center, New York, NY 10021.
0 1997 by Elsevier Science Inc. 655 Avenue of the Americas, New York, NY 10010
284
Transplantation
Proceedings,
29, 284 (1997)
In Vivo Hyperexpression of Transforming Growth Factor-P, in Humans: Stimulation by Cyclosporine G.-T. Shin, A. Khanna, V.K. Sharma, R. Ding, S. Azizlerli,
S
TUDIES on the mechanisms of action of cyclosporine (CyA) have shown that the drug-cyclophilin complex binds and inhibits calcineurin, a calcium and calmodulindependent serine-threonine phosphatase. This inactivation prevents dephosphorylation of nuclear factor of activated T cells (NF-AT), the nuclear import of NF-AT, and the formation of a transcriptionally active NF-AT complex. The net consequence, inhibition of IL-2 gene expression at the transcriptional level, is considered to be the primary mechanism for the immunosuppressive activity of CyA.l We identified, for the first time, that CyA, in striking contrast to its inhibitory activity on IL-2 gene transcription, stimulates transforming growth factor-p, (TGF-0,) expression.2 We also found that CyA can inhibit new DNA synthesis in mammalian cells via a TGF-&-dependent mechanism.3 TGF-/3, is a potent immunosuppressant and a fibrogenic cytokine.495 Our previous studies demonstrating a stimulatory effect of CyA on TGF-/3, expression were all in vitro studies.2,3 We have determined herein whether CyA induces hyperexpression of TGF-/3, in vivo in humans. PATIENTS AND METHODS The in vivo effect of CyA on TGF-P, expression was investigated in living-donor renal allograft recipients preconditioned with a regimen of oral CyA, 6 mdkg per day, for 7 days’ pretransplantation. The patients did not receive any other immunosuppressive drug during CyA therapy. Sera (n = 18 samples), isolated from the venous blood obtained prior to and after completion of CyA therapy (and prior to transplantation), were tested for TGF-P, using a sandwich ELISA as described.3 RESULTS
All nine patients showed an increase in TGF-& protein concentration following CyA therapy; the mean 2 SEM of TGF-/3, protein concentration increased from 174 t 61
0041-1315/97/$17.00 PII SOO41-1345(96)00094-2
B. Li, and M. Suthanthiran
pg/mL to 354 2 65 pg/mL (P = .00.5 by paired t test) following CyA monotherapy. DISCUSSION
Our first demonstration of CyA’s stimulatory activity in vivo in humans lends credence to the hypothesis that CyA functions as an immunosuppressant not only by inhibiting the production of proinflammatory cytokines (eg, IL-2) but also by promoting the expression of TGF-P,, a potent immunosuppressive cytokine. The stimulatory activity of CyA also advances a mechanism for the interstitial fibrosis observed with the clinical use of CyA, since TGF-P, is a fibrogenic cytokine. The contribution of CyA-induced hyperexpression of TGF-P, to in vivo immunosuppression facilitating organ graft survival, and to renal fibrosis, needs to be explored in experiments where TGF-& expression is specifically downregulated (eg, TGF-&-specific antisense oligonucleotides). REFERENCES 1. Suthanthiran M, Morris RE, Strom TB: Am J Kidney Dis 1996:28, 1.59 2. Li B, Sehajpal P, Khanna A, et al: J Exp Med 1991:174, 1259 3. Khanna AK, Li B, Stenzel KH, et al: Transplantation 199457, 577 4. Roberts AB, Sporn MB: Growth Factors 8:1, 1993 5. Shull MM, Ormsby I, Kier AB, et al: Nature 359:693, 1992
From the Rogosin Institute, New York. This work was supported in part by an award from the National Institutes of Health (A126932). Address reprint requests to G.-T. Shin, the Rogosin Institute, Division of Nephrology, Department of Transplantation Medicine & Extracorporeal Therapy, New York Hospital-Cornell Medical Center, New York, NY 10021.
0 1997 by Elsevier Science Inc. 655 Avenue of the Americas, New York, NY 10010
284
Transplantation
Proceedings,
29, 284 (1997)