Fan Junfu, Tong Gaozan, Chen Xixi, Li Santie, Yu Ying, Zhu Shunan, Zhu Kunxuan, Hu Zijing, Dong Yonggan, Chen Rui, Zhu Junjie, Gong Wenjie, Hu Zhicheng, Zhou Bin, Chen Yiming, Jin Litai, Cong Weitao
School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, Zhejiang, China.
Department of Pharmacy, Taizhou Central Hospital (Taizhou University Hospital), Taizhou, Zhejiang, China.
Br J Pharmacol. 2023 Jan;180(1):44-61. doi: 10.1111/bph.15945. Epub 2022 Sep 29.
Liver fibrosis is a serious cause of morbidity and mortality worldwide characterized by accumulation of extracellular matrix produced by hepatic stellate cells (HSCs). The protein kinase CK2 is a pro-survival kinase overexpressed in human tumours. However, the biological role of CK2 in liver fibrosis is largely unknown. We aimed to investigate the mechanism by which CK2 promotes liver fibrosis.
In vitro, LX-2 cells were stimulated with transforming growth factor-β (TGF-β). HSCs were also isolated for research. In vivo, the adeno-associated virus AAV-sh-csnk2a1 was used to knockdown CK2α specifically in HSCs, and CX-4945 was used to pharmacologically inhibit the enzymatic activity of CK2 in murine models of fibrosis induced by carbon tetrachloride (CCl ) and a 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) diet. Histological and biochemical analyses were performed to study the involvement of CK2 in regulation of fibrogenic and fibrolytic factors as well as activation properties of HSCs.
HSC-specific genetic invalidation of CK2α or pharmacological inhibition of CK2 protected mice treated with CCl or fed a DDC diet against liver fibrosis and HSC accumulation. Mechanistically, CK2α, which bound to Smoothened (SMO), was a positive regulator of the Hedgehog signal transduction pathway. CK2 prevented ubiquitination and proteasomal degradation of SMO, which was abolished by knockdown of CK2α or pharmacological inhibition of CK2.
CK2 activation is critical to sustain the activated and fibrogenic phenotype of HSCs via SMO stabilization. Therefore, inactivation of CK2 by CX-4945 may be of therapeutic interest for liver fibrotic diseases.
肝纤维化是全球范围内导致发病和死亡的严重原因，其特征是肝星状细胞（HSCs）产生的细胞外基质积聚。蛋白激酶CK2是一种在人类肿瘤中过表达的促生存激酶。然而，CK2在肝纤维化中的生物学作用在很大程度上尚不清楚。我们旨在研究CK2促进肝纤维化的机制。
在体外，用转化生长因子-β（TGF-β）刺激LX-2细胞。也分离出肝星状细胞用于研究。在体内，腺相关病毒AAV-sh-csnk2a1用于在肝星状细胞中特异性敲低CK2α，并且在四氯化碳（CCl）和3,5-二乙氧基羰基-1,4-二氢可力丁（DDC）饮食诱导的纤维化小鼠模型中，使用CX-4945从药理学上抑制CK2的酶活性。进行组织学和生化分析以研究CK2在调节纤维化和纤溶因子以及肝星状细胞的激活特性中的作用。
CK2α的肝星状细胞特异性基因失活或CK2的药理学抑制保护用CCl处理或喂食DDC饮食的小鼠免受肝纤维化和肝星状细胞积聚的影响。从机制上讲，与平滑肌瘤（SMO）结合的CK2α是刺猬信号转导途径的正调节因子。CK2阻止了SMO的泛素化和蛋白酶体降解，CK2α的敲低或CK2的药理学抑制消除了这种降解。
CK2激活对于通过SMO稳定维持肝星状细胞的活化和纤维化表型至关重要。因此，CX-4945使CK2失活可能对肝纤维化疾病具有治疗意义。
