TY - JOUR
T1 - Cell-penetrating peptides selectively targeting SMAD3 inhibit profibrotic TGF-β signaling
AU - Kang, Jeong Han
AU - Jung, Mi Yeon
AU - Yin, Xueqian
AU - Andrianifahanana, Mahefatiana
AU - Hernandez, Danielle M.
AU - Leof, Edward B.
PY - 2017/6/30
Y1 - 2017/6/30
N2 - TGF-β is considered a master switch in the pathogenesis of organ fibrosis. The primary mediators of this activity are the SMAD proteins, particularly SMAD3. In the current study, we have developed a cell-penetrating peptide (CPP) conjugate of the HIV TAT protein that is fused to an aminoterminal sequence of sorting nexin 9 (SNX9), which was previously shown to bind phosphorylated SMAD3 (pSMAD3). We determined that specifically preventing the nuclear import of pSMAD3 using the TAT-SNX9 peptide inhibited profibrotic TGF-β activity in murine cells and human lung fibroblasts as well as in vivo with no demonstrable toxicity. TGF-β signaling mediated by pSMAD2, bone morphogenetic protein 4 (BMP4), EGF, or PDGF was unaffected by the TAT-SNX9 peptide. Furthermore, while the TAT-SNX9 peptide prevented TGF-β's profibrotic activity in vitro as well as in 2 murine treatment models of pulmonary fibrosis, a 3-amino acid point mutant that was unable to bind pSMAD3 proved ineffective. These findings indicate that specifically targeting pSMAD3 can ameliorate both the direct and indirect fibroproliferative actions of TGF-β.
AB - TGF-β is considered a master switch in the pathogenesis of organ fibrosis. The primary mediators of this activity are the SMAD proteins, particularly SMAD3. In the current study, we have developed a cell-penetrating peptide (CPP) conjugate of the HIV TAT protein that is fused to an aminoterminal sequence of sorting nexin 9 (SNX9), which was previously shown to bind phosphorylated SMAD3 (pSMAD3). We determined that specifically preventing the nuclear import of pSMAD3 using the TAT-SNX9 peptide inhibited profibrotic TGF-β activity in murine cells and human lung fibroblasts as well as in vivo with no demonstrable toxicity. TGF-β signaling mediated by pSMAD2, bone morphogenetic protein 4 (BMP4), EGF, or PDGF was unaffected by the TAT-SNX9 peptide. Furthermore, while the TAT-SNX9 peptide prevented TGF-β's profibrotic activity in vitro as well as in 2 murine treatment models of pulmonary fibrosis, a 3-amino acid point mutant that was unable to bind pSMAD3 proved ineffective. These findings indicate that specifically targeting pSMAD3 can ameliorate both the direct and indirect fibroproliferative actions of TGF-β.
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U2 - 10.1172/JCI88696
DO - 10.1172/JCI88696
M3 - Article
C2 - 28530637
AN - SCOPUS:85021729207
SN - 0021-9738
VL - 127
SP - 2541
EP - 2554
JO - Journal of Clinical Investigation
JF - Journal of Clinical Investigation
IS - 7
ER -