TY - JOUR
T1 - Persistence of cirrhosis is maintained by intrahepatic regulatory T cells that inhibit fibrosis resolution by regulating the balance of tissue inhibitors of metalloproteinases and matrix metalloproteinases
AU - Zhang, Xiaohui
AU - Feng, Min
AU - Liu, Xin
AU - Bai, Li
AU - Kong, Ming
AU - Chen, Yu
AU - Zheng, Sujun
AU - Liu, Shuang
AU - Wan, Yu-Jui Yvonne
AU - Duan, Zhongping
AU - Han, Yuan Ping
PY - 2016/3/1
Y1 - 2016/3/1
N2 - Fibrosis is the result of the abnormal accumulation of the extracellular matrix and ineffective clearance of fibroplasia. CD4+CD25+Foxp3+ regulatory T cells (Tregs) are immunosuppressive lymphocytes that are highly expressed in the fibrotic tissues and peripheral blood of patients with cirrhosis or hepatocellular carcinoma. The role of Tregs in the progression of liver fibrosis is not well understood. Our experiments reveal that abundant of Tregs was scattered around sites of fibroplasia. Conversely, the depletion of Tregs promoted the resolution of liver fibrosis. As a consequence of Tregs depletion, the expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) was altered; mmp9 and timp1 were reduced, whereas mmp2 and mmp14 were enhanced. The mmp9/timp1, mmp13/timp1, and mmp14/timp2 ratios were significantly increased in association with fibrosis resolution. Kupffer cells (KCs) are the main source of MMP. We observed that when KCs were cocultured with Tregs, the Tregs were able to inhibit MMP expression of KCs even at a low ratio; and anti-transforming growth factor-β (TGF-β) significantly reversed the inhibition of Tregs on MMP. Meanwhile, we also found that after Tregs depletion, TGF-β levels decreased in the mice liver, unlike in fibrosis. Furthermore, double depletion of both KCs and Tregs did not cause fiber resolution in mice. Thus, our results demonstrate that the persistence of liver cirrhosis is maintained by increased Tregs in the sites of fibroplasia and the subsequent regulation of the MMP/TIMP balance and that the suppression of KC-mediated MMP expression contributed to the regulatory process.
AB - Fibrosis is the result of the abnormal accumulation of the extracellular matrix and ineffective clearance of fibroplasia. CD4+CD25+Foxp3+ regulatory T cells (Tregs) are immunosuppressive lymphocytes that are highly expressed in the fibrotic tissues and peripheral blood of patients with cirrhosis or hepatocellular carcinoma. The role of Tregs in the progression of liver fibrosis is not well understood. Our experiments reveal that abundant of Tregs was scattered around sites of fibroplasia. Conversely, the depletion of Tregs promoted the resolution of liver fibrosis. As a consequence of Tregs depletion, the expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) was altered; mmp9 and timp1 were reduced, whereas mmp2 and mmp14 were enhanced. The mmp9/timp1, mmp13/timp1, and mmp14/timp2 ratios were significantly increased in association with fibrosis resolution. Kupffer cells (KCs) are the main source of MMP. We observed that when KCs were cocultured with Tregs, the Tregs were able to inhibit MMP expression of KCs even at a low ratio; and anti-transforming growth factor-β (TGF-β) significantly reversed the inhibition of Tregs on MMP. Meanwhile, we also found that after Tregs depletion, TGF-β levels decreased in the mice liver, unlike in fibrosis. Furthermore, double depletion of both KCs and Tregs did not cause fiber resolution in mice. Thus, our results demonstrate that the persistence of liver cirrhosis is maintained by increased Tregs in the sites of fibroplasia and the subsequent regulation of the MMP/TIMP balance and that the suppression of KC-mediated MMP expression contributed to the regulatory process.
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U2 - 10.1016/j.trsl.2015.10.008
DO - 10.1016/j.trsl.2015.10.008
M3 - Article
C2 - 26613891
AN - SCOPUS:84959307329
VL - 169
SP - 67
EP - 79
JO - Translational Research
JF - Translational Research
SN - 1931-5244
ER -