Salvianolic acid B suppresses hepatic fibrosis by inhibiting ceramide glucosyltransferase in hepatic stellate cells
作者:Zi-bo Li、Lin Jiang、Jia-dong Ni、Yuan-hang Xu、Fang Liu、Wen-ming Liu、Shao-gui Wang、Zhong-qiu Liu、Cai-yan Wang
DOI:10.1038/s41401-022-01044-9
日期:——
UDP-glucose ceramide glucosyltransferase (UGCG) is the first key enzyme in glycosphingolipid (GSL) metabolism that produces glucosylceramide (GlcCer). Increased UGCG synthesis is associated with cell proliferation, invasion and multidrug resistance in human cancers. In this study we investigated the role of UGCG in the pathogenesis of hepatic fibrosis. We first found that UGCG was over-expressed in fibrotic livers and activated hepatic stellate cells (HSCs). In human HSC-LX2 cells, inhibition of UGCG with PDMP or knockdown of UGCG suppressed the expression of the biomarkers of HSC activation (α-SMA and collagen I). Furthermore, pretreatment with PDMP (40âμM) impaired lysosomal homeostasis and blocked the process of autophagy, leading to activation of retinoic acid signaling pathway and accumulation of lipid droplets. After exploring the structure and key catalytic residues of UGCG in the activation of HSCs, we conducted virtual screening, molecular interaction and molecular docking experiments, and demonstrated salvianolic acid B (SAB) from the traditional Chinese medicine Salvia miltiorrhiza as an UGCG inhibitor with an IC50 value of 159âμM. In CCl4-induced mouse liver fibrosis, intraperitoneal administration of SAB (30âmgâ·âkgâ1â·âdâ1, for 4 weeks) significantly alleviated hepatic fibrogenesis by inhibiting the activation of HSCs and collagen deposition. In addition, SAB displayed better anti-inflammatory effects in CCl4-induced liver fibrosis. These results suggest that UGCG may represent a therapeutic target for liver fibrosis; SAB could act as an inhibitor of UGCG, which is expected to be a candidate drug for the treatment of liver fibrosis.
UDP-葡萄糖神经酰胺葡萄糖基转移酶(UGCG)是糖磷脂(GSL)代谢过程中产生葡萄糖基甘油酰胺(GlcCer)的第一个关键酶。UGCG 合成的增加与人类癌症的细胞增殖、侵袭和多药耐药性有关。在这项研究中,我们探讨了 UGCG 在肝纤维化发病机制中的作用。我们首先发现,UGCG 在纤维化肝脏和活化的肝星状细胞(HSCs)中过度表达。在人 HSC-LX2 细胞中,用 PDMP 抑制 UGCG 或敲除 UGCG 可抑制 HSC 活化生物标志物(δ-SMA 和胶原 I)的表达。此外,PDMP(40μM)还会破坏溶酶体的稳态,阻断自噬过程,导致维甲酸信号通路的激活和脂滴的积累。在探索了UGCG在激活造血干细胞过程中的结构和关键催化残基后,我们进行了虚拟筛选、分子相互作用和分子对接实验,证明中药丹参中的丹参酚酸B(SAB)是一种UGCG抑制剂,其IC50值为159δ¼M。此外,SAB对CCl4诱导的肝纤维化具有更好的抗炎作用。这些结果表明,UGCG可能是肝纤维化的治疗靶点;SAB可作为UGCG的抑制剂,有望成为治疗肝纤维化的候选药物。