Chaihu shugan powder ameliorated chronic pancreatitis by reprogramming SMS2-mediated sphingolipid metabolism in M1 macrophages.

BACKGROUND

Chronic pancreatitis (CP) lacks targeted therapies. Its pathogenesis involves macrophage polarization-activated pancreatic stellate cells (PSCs), with sphingolipid metabolism playing an emerging role. The traditional formula Chaihu shugan powder (CSP) shows clinical potential for CP treatment.

PURPOSE: This study aimed to elucidate the role of CSP in CP and to identify the key components and underlying mechanisms involved in macrophage polarization-PSC activation crosstalk.

STUDY

DESIGN

We investigated the effects of CSP in vivo and in vitro, identified differentially altered sphingolipids and metabolic enzymes, and assessed their impact on macrophage polarization and PSC activation, followed by screening for the active components of CSP.

METHODS

CP was induced in mice by cerulein injections for four weeks, with CSP treatment given in the final two weeks. Bone marrow-derived macrophages and primary PSCs were isolated for in vitro studies. Underlying targets and mechanisms were explored using targeted sphingolipid analysis, scRNA-seq, flow cytometry and genetic knockdown, while molecular docking and molecular interaction helped identify active CSP components.

RESULTS

CSP significantly attenuated pancreatic fibrosis and M1 macrophage polarization, and restored sphingolipid metabolism in both serum and pancreas. Elevated sphingomyelin (18:1) and sphingomyelin synthase 2 (SMS2) in macrophages were identified as promoting PSC activation. Hesperetin in CSP bound to SMS2, inhibiting M1 macrophage polarization and PSC activation.

CONCLUSION

CSP ameliorates CP partially through hesperetin-targeted SMS2, reprograms sphingolipid metabolism, and suppresses M1 macrophage-induced PSC activation.