Twenty 9O-substituted palmatine derivatives were prepared and tested for their biological effect against collagen α1 (I) (COL1A1) promotor in human hepatic stellate LX-2 cells. The structure−activity relationship (SAR) indicated that the introduction of a benzyl motif on the 9O atom was favorable for activity. Among them, compound 6c provided the highest inhibitory effect against COL1A1 with an IC50 value of 3.98 μM, and it also dose-dependently inhibited the expression of fibrogenic COL1A1, α-soomth muscle actin (α-SMA), matrix metalloprotein 2 (MMP2) in both mRNA and protein levels, indicating extensive inhibitory activity against fibrogenesis. A further primary mechanism study indicated that it might repress the hepatic fibrogenesis via inhibiting both canonical transforming growth factor-beta 1 (TGF-β1)/Smads and non-canonical janus-activated kinase 1 (JAK1)/singal transducer and activator of transcription 3 (STAT3) signaling pathways. Additionally, 6c owned a high safety profile with the LD50 value of over 1000 mg·kg−1 in mice. These results identified palmatine derivatives as a novel class of anti-fibrogenic agents, and provided powerful information for further structure optimization.
The farnesoid X receptor (FXR) plays a crucial role in regulating the metabolism of bile acids, lipids, and sugars. Consequently, it is implicated in the treatment of various diseases, including cholestasis, diabetes, hyperlipidemia, and cancer. The advancement of novel FXR modulators holds immense importance, especially in managing metabolic disorders. In this study, a series of oleanolic acid (OA) derivatives bearing 12β-O-(γ-glutamyl) groups were designed and synthesized. Using a yeast one-hybrid assay, we established a preliminary structure–activity relationship (SAR) and identified the most potent compound, 10b, which selectively antagonizes FXR over other nuclear receptors. Compound 10b can differentially modulate the downstream genes of FXR, including with the upregulation of the CYP7A1 gene. In vivo testing revealed that 10b (100 mg·Kg−1) not only effectively inhibits lipid accumulation in the liver but also prevents liver fibrosis in both BDL rats and HFD mice. Molecular modeling indicated that the branched substitution of 10b extends into the H11–H12 region of FXR-LBD, possibly accounting for its CYP7A1 upregulation, which is different from a known OA 12β-alkonate. These findings suggest that 12-glutamyl OA derivative 10b represents a promising candidate for the treatment of nonalcoholic steatohepatitis (NASH).
A promising therapeutic approach in oncology involves immune checkpoint blockade (ICB), which stimulates anti-tumor immune responses. Nevertheless, the effectiveness of this treatment in clinical settings remains limited, underscoring the need for complementary strategies. Recent studies highlight the potential of type I interferon (IFN-I) inducers to reprogram the tumor microenvironment and enhance ICB outcomes. Herein, through high-content screening of a natural compound library, we identified daurisoline (DS), a bioactive alkaloid extracted from the Chinese herbal medicine Rhizoma Menispermi, as a potent inducer of IFN-I signaling. Our findings indicated that DS up-regulates interferon responses and pro-inflammatory cytokine expression in a TANK-binding kinase 1 (TBK1)-dependent manner. In vivo, DS exhibited marked tumor growth inhibition by activating dendritic cells, macrophages, and CD8 + T cells, thereby enhancing anti-tumor immunity. Utilizing the LiP-SMap approach, we identified low-density lipoprotein receptor-related protein 1 (LRP1) as the direct target of DS. Mechanistically, the binding of DS to LRP1 substantially disrupted lysosomal function, which subsequently triggered 5′-azacytidine-induced protein 2-mediated TBK1 activation and IFN-I production. Furthermore, DS demonstrated synergistic effects with anti-programmed death 1 therapy and a stimulator of interferon genes agonist by remodeling the immunosuppressive microenvironment. Collectively, our findings establish LRP1 as a novel therapeutic target for cancer immunotherapy and highlight DS-driven immune reprogramming as a translatable strategy to potentiate ICB efficacy.
There exists a huge number of patients suffering from chronic liver disease worldwide. As a disease with high incidence and mortality worldwide, strengthening the research on the pathogenesis of chronic liver disease and the development of novel drugs is an important issue related to the health of all human beings. Phosphorylation modification of proteins plays a crucial role in cellular signal transduction, and phosphatases are involved in the development of liver diseases. Therefore, this article summarized the important role of protein phosphatases in chronic liver disease with the aim of facilitating the development of drugs targeting protein phosphatases for the treatment of chronic liver disease.