Eun Hye Lee1, Kwang-Il Park2, Kwang-Youn Kim2, Ju-Hee Lee3, Eun Jeong Jang4, Sae Kwang Ku4, Sang Chan Kim4, Ho Young Suk5, Ji Young Park1, Su Youn Baek6, Young Woo Kim7. 1. Department of Pathology, School of Medical Science, Kyungpook National University, Daegu 41566, South Korea. 2. Korea Institute of Oriental Medicine, Daegu 41062, South Korea. 3. College of Korean Medicine, Dongguk University, Gyeongju 38066, South Korea. 4. College of Oriental Medicine, Daegu Haany University, Gyeongsan 38610, South Korea. 5. Yeungnam University, Gyeongsan 38541, South Korea. 6. College of Oriental Medicine, Daegu Haany University, Gyeongsan 38610, South Korea. Electronic address: rhodeus@dhu.ac.kr. 7. College of Korean Medicine, Dongguk University, Gyeongju 38066, South Korea; College of Oriental Medicine, Daegu Haany University, Gyeongsan 38610, South Korea. Electronic address: ywkim@dhu.ac.kr.
Abstract
BACKGROUND: Recent reports highlighted the possibility that Yes-associated protein (YAP) and transforming growth factor-β1 (TGF-β1) can act as critical regulators of hepatic stellate cells (HSCs) activation; therefore, it is natural for compounds targeting Hippo/YAP and TGF-β1/Smad signaling pathways to be identified as potential anti-fibrotic candidates. PURPOSE: Liquiritigenin (LQ) is an aglycone of liquiritin and has been reported to protect the liver from injury. However, its effects on the Hippo/YAP and TGF-β1/Smad pathways have not been identified to date. METHODS: We conducted a series of experiments using CCl4-induced fibrotic mice and cultured LX-2 cells. RESULT: LQ significantly inhibited liver fibrosis, as indicated by decreases in regions of hepatic degeneration, inflammatory cell infiltration, and the intensity of α-smooth muscle actin (α-SMA) staining in mice. Moreover, LQ blocked the TGF-β1-induced phosphorylation of Smad 3, and the transcript levels of plasminogen activator inhibitor-1 (PAI-1) and matrix metalloproteinase-2 (MMP-2) in LX-2 cells, which is similar with resveratrol and oxyresveratrol (positive controls). Furthermore, LQ increased activation of large tumor suppressor kinase 1 (LATS1) with the induction of YAP phosphorylation, thereby preventing YAP transcriptional activity and suppressing the expression of exacerbated TGF-β1/Smad signaling molecules. CONCLUSION: These results clearly show that LQ ameliorated experimental liver fibrosis by acting on the TGF-β1/Smad and Hippo/YAP pathways, indicating that LQ has the potential for effective treatment of liver fibrosis.
BACKGROUND: Recent reports highlighted the possibility that Yes-associated protein (YAP) and transforming growth factor-β1 (TGF-β1) can act as critical regulators of hepatic stellate cells (HSCs) activation; therefore, it is natural for compounds targeting Hippo/YAP and TGF-β1/Smad signaling pathways to be identified as potential anti-fibrotic candidates. PURPOSE:Liquiritigenin (LQ) is an aglycone of liquiritin and has been reported to protect the liver from injury. However, its effects on the Hippo/YAP and TGF-β1/Smad pathways have not been identified to date. METHODS: We conducted a series of experiments using CCl4-induced fibrotic mice and cultured LX-2 cells. RESULT: LQ significantly inhibited liver fibrosis, as indicated by decreases in regions of hepatic degeneration, inflammatory cell infiltration, and the intensity of α-smooth muscle actin (α-SMA) staining in mice. Moreover, LQ blocked the TGF-β1-induced phosphorylation of Smad 3, and the transcript levels of plasminogen activator inhibitor-1 (PAI-1) and matrix metalloproteinase-2 (MMP-2) in LX-2 cells, which is similar with resveratrol and oxyresveratrol (positive controls). Furthermore, LQ increased activation of large tumor suppressor kinase 1 (LATS1) with the induction of YAP phosphorylation, thereby preventing YAP transcriptional activity and suppressing the expression of exacerbated TGF-β1/Smad signaling molecules. CONCLUSION: These results clearly show that LQ ameliorated experimental liver fibrosis by acting on the TGF-β1/Smad and Hippo/YAP pathways, indicating that LQ has the potential for effective treatment of liver fibrosis.