Gentisic acid prevents colorectal cancer metastasis via blocking GPR81-mediated DEPDC5 degradation.

BACKGROUND: Metastasis driven by epithelial-mesenchymal transition (EMT) remains a significant contributor to the poor prognosis of colorectal cancer (CRC), and requires more effective interventions. GPR81 signaling has been linked to tumor metastasis, while lacks an efficient specific inhibitor. PURPOSE: Our study aimed to investigate the effect and mechanism of Gentisic acid on colorectal cancer (CRC) metastasis. STUDY DESIGN: A lung metastasis mouse model induced by tail vein injection and a subcutaneous graft tumor model were used. Gentisic acid (GA) was administered by an intraperitoneal injection. HCT116 was treated with lactate to establish an in vitro model. METHODS: MC38 cells with mCherry fluorescent protein were injected into tail vein to investigate lung metastasis ability in vivo. GA was administered by intraperitoneal injection for 3 weeks. The therapeutic effect was evaluated by survival rates, histochemical analysis, RT-qPCR and live imaging. The mechanism was explored using small interfering RNA (siRNA), Western blotting, RT-qPCR and immunofluorescence. RESULTS: GA had a therapeutic effect on CRC metastasis and improved survival rates and pathological changes in dose-dependent manner. GA emerged as an GPR81 inhibitor, effectively suppressed EMT and mTOR signaling in CRC induced by lactate both in vivo and in vitro. Mechanistically, GA halted lactate-induce degradation of DEPDC5 through impeding the activation of Chaperone-mediated autophagy (CMA). CONCLUSION: CMA-mediated DEPDC5 degradation is crucial for lactate/GPR81-induced CRC metastasis, and GA may be a promising candidate for metastasis by inhibiting GPR81 signaling.

Vanillic acid restores homeostasis of intestinal epithelium in colitis through inhibiting CA9/STIM1-mediated ferroptosis.

The damage of integrated epithelial epithelium is a key pathogenic factor and closely associated with the recurrence of ulcerative colitis (UC). Here, we reported that vanillic acid (VA) exerted potent therapeutic effects on DSS-induced colitis by restoring intestinal epithelium homeostasis via the inhibition of ferroptosis. By the CETSA assay and DARTS assay, we identified carbonic anhydrase IX (CAIX, CA9) as the direct target of VA. The binding of VA to CA9 causes insulin-induced gene-2 (INSIG2) to interact with stromal interaction molecule 1 (STIM1), rather than SREBP cleavage-activating protein (SCAP), leading to the translocation of SCAP-SREBP1 from the endoplasmic reticulum (ER) to the Golgi apparatus for cleavage into mature SREBP1. The activation of SREBP1 induced by VA then significantly facilitated the transcription of stearoyl-CoA desaturase 1 (SCD1) to exert an inhibitory effect on ferroptosis. By inhibiting the excessive death of intestinal epithelial cells caused by ferroptosis, VA effectively preserved the integrity of intestinal barrier and prevented the progression of unresolved inflammation. In conclusion, our study demonstrated that VA could alleviate colitis by restoring intestinal epithelium homeostasis through CA9/STIM1-mediated inhibition of ferroptosis, providing a promising therapeutic candidate for UC.

Inhibiting sorting nexin 10 promotes mucosal healing through SREBP2-mediated stemness restoration of intestinal stem cells.

Intestinal stem cell (ISC) is a promising therapeutic target for inflammatory bowel disease. Cholesterol availability is critical for ISC stemness. Low plasma cholesterol is a typical feature of Crohn's disease (CD); however, its impact on mucosal healing remains unclear. Here, we identified an essential role of sorting nexin 10 (SNX10) in maintaining the stemness of ISCs. SNX10 expression in intestinal tissues positively correlates with the severity of human CD and mouse colitis. Conditional SNX10 knockout in intestinal epithelial cells or ISCs promotes intestinal mucosal repair by maintaining the ISC population associated with increased intracellular cholesterol synthesis. Disassociation of ERLIN2 with SCAP by SNX10 deletion enhances the activation of SREBP2, resulting in increased cholesterol biosynthesis. DC-SX029, a small-molecule inhibitor of SNX10, was used to verify the druggable potential of SNX10 for the treatment of patients with CD. Our study provides a strategy for mucosal healing through SREBP2-mediated stemness restoration of ISCs.

Paeoniflorin prevents aberrant proliferation and differentiation of intestinal stem cells by controlling C1q release from macrophages in chronic colitis.

The pathological features of inflammatory bowel disease necessitate therapeutic strategies aimed at restoring intestinal mucosal barrier function in addition to controlling inflammation. Paeoniflorin, a bioactive herbal constituent isolated from the root of Paeonia albiflora Pall, has been reported to protect against acute colitis in mice. However, the direct molecular target of paeoniflorin in preventing colitis remains elusive. Here, we evaluated the therapeutical effects of Paeoniflorin using IL-10-/- chronic colitis model, and explored the precise mechanism of action involved. Our results demonstrated that intragastric administration of Paeoniflorin significantly ameliorated inflammatory response and restored the aberrant intestinal proliferation and differentiation in IL-10-/-colitis mice. By utilizing a chemical biology approach, we identified C1qa, a crucial component of C1q, is the direct target of Paeoniflorin. Binding of Paeoniflorin to C1qa prevented the cleavage of C1q on macrophages, resulting in the aggregation of surface membrane-anchored C1q and the diminished C1q secretion. The excessive surface membrane-anchored C1q significantly enhanced the phagocytic capability of macrophages and promoted the elimination of infiltrated bacteria and inflammatory cells in mouse colon. The reduced C1q secretion conferred by Paeoniflorin dampened Wnt/ß-catenin signaling activation, thereby rectifying the aberrant proliferation and differentiation of intestinal stem cells (ISCs). In summary, our study demonstrates that Paeoniflorin can orchestrate mucosal healing and intestinal inflammation elimination through C1q-bridged macrophage-ISCs crosstalk, highlighting a novel strategy to treat chronic colitis by restoring mucosal homeostasis via targeting C1q.

Total glucosides of Paeony restores intestinal barrier function through inhibiting Lyn/Snail signaling pathway in colitis mice.

BACKGROUND: Inflammatory bowel disease (IBD) is an autoimmune disease. The pathogenesis of IBD is complicated and intestinal mucosal barrier damage is considered as the trigger factor for the initiation and recurrence of IBD. Total Glucosides of Paeony (TGP) has shown good inhibitory effects on immune-inflammation in clinic studies. However, its effect and mechanism on IBD are largely unknown. PURPOSE: The purpose of this study is to evaluate the effect and mechanism of TGP on IBD. STUDY DESIGN: DSS-induced colitis mouse model was used. TGP was given by gavage. Caco-2 cells were stimulated by outer membrane vesicles (OMV) to establish an in vitro model. METHODS: C57BL/6 mice were divided into normal control group, model group, mesalazine group, paeoniflorin (PA) group, high-dose group of TGP, and low-dose group of TGP. The model was induced with 2.5% DSS for 7 days, and TGP was intragastrically administered for 10 days. The therapeutic effect of TGP was evaluated by symptoms, histochemical analysis, RT-qPCR and ELISA. The mechanism was explored by intestinal permeability, Western blot and immunofluorescence in vivo and in vitro. RESULTS: Our results showed that TGP could significantly improve the symptoms and pathological changes, with reduced levels of TNF-α, IL-17A, IL-23 and IFN-γ in the colon tissues and serum under a dose-dependent manner. TGP also reduced the intestinal permeability and restored the protein expression of tight junction and adherens junction proteins of intestinal epithelial cells in vivo and in vitro. Furthermore, TGP could inhibit the expression of p-Lyn and Snail and prevent Snail nuclear localization, thereby maintaining tight and adherens junctions. CONCLUSION: TGP effectively improves the symptoms of DSS-induced colitis in mice, protects the intestinal epithelial barrier by inhibiting the Lyn/Snail signaling pathway, and maybe a promise therapeutic agent for IBD treatment.