Pirfenidone alleviates chronic pancreatitis via suppressing the activation of pancreatic stellate cells and the M1 polarization of macrophages

Abstract

In the realm of fibroinflammatory conditions, chronic pancreatitis (CP) stands out as a particularly challenging ailment, lacking a dedicated, approved treatment. The potential of Pirfenidone (PFD), a drug originally used for treating idiopathic pulmonary fibrosis (IPF), in addressing CP's fibrotic aspects has sparked new interest. This investigation focused on the role of PFD in diminishing fibrosis and immune response in CP, using a mouse model induced by caerulein. The research extended to in vitro studies examining the influence of PFD on pancreatic stellate cells' (PSCs) behavior and the polarization of macrophages into M1 and M2 types. Advanced techniques like RNA sequencing and comprehensive data analyses were employed to decode the molecular interactions of PFD with PSCs. Supplementary experiments using techniques such as quantitative real-time PCR, western blotting, and immunofluorescence were also implemented. Results showed a notable reduction in pancreatic damage in PFD-treated mice, manifested through decreased acinar cell atrophy, lower collagen deposition, and a reduction in macrophage presence. Further investigation revealed PFD's capacity to hinder PSCs' migration, growth, and activation, alongside a reduction in the production and secretion of extracellular matrix proteins. This effect is primarily achieved by interfering with signaling pathways such as TGF-β/Smad, Wnt/β-catenin, and JAK/STAT. Additionally, PFD selectively hampers M1 macrophage polarization through the STAT3 pathway, without impacting M2 polarization. These outcomes highlight PFD's dual mechanism in moderating PSC activity and M1 macrophage polarization, positioning it as a promising candidate for CP therapy.

Keywords: Chronic pancreatitis; Fibrosis; Macrophage; Pancreatic stellate cell; Pirfenidone.