From scRNA-seq to therapeutic targets: Unveiling the impact of activated mast cells on intestinal dysfunction in acute pancreatitis

Table 1 Key outcome summary

Key outcome	Observation in AP small intestine	Implication
Intestinal cellular heterogeneity	scRNA-seq of the small intestine identified 17 distinct cell clusters from > 33000 cells across the control, AP1, and AP2 samples	Provides a high-resolution atlas of the small-intestinal cell composition and reveals dynamic shifts during early AP
Intestinal MC activation	scRNA-seq showed an apparent reduction of MC recovery but immunofluorescence staining (c-Kit and toluidine blue) confirmed stable MC counts with degranulation	Highlights activation-induced MC fragility during dissociation and underscores MC mediator release as a driver of barrier dysfunction
CCL5 upregulation in intestinal MCs	scRNA-seq and flow cytometry demonstrated significant CCL5 overexpression in MCs in the AP1 and AP2 groups	Identifies CCL5 as a key chemokine, mediating neutrophil and macrophage recruitment to the gut barrier
Tight junction disruption in small intestine	IHC revealed decreased expression of ZO-1 and occludin in AP1 and AP2 intestinal epithelia	Confirms compromised epithelial barrier integrity at early stages of AP
Programmed cell death in enterocytes	IHC showed increase in cleaved caspase-3 (apoptosis) and p-MLKL (necroptosis) levels in intestinal enterocytes from the control to AP1 to AP2 group	Demonstrates enterocyte loss via multiple cell-death pathways contributing to barrier breakdown

AP: Acute pancreatitis; MC: Mast cell; IHC: Immunohistochemistry.

Table 2 Recommendations for future research

Recommendation	Specific approach (key points)
Longitudinal single-cell profiling	(1) Time points (post AP induction): Early (2 hours, 6 hours, and 24 hours), mid (3 days and 7 days) and late (14 days and 28 days); and (2) Assays: FITC-dextran permeability and serum LPS (barrier); histological score and IHC/FACS for neutrophil/macrophage infiltration along with IL-6/TGF-β (inflammation); Masson’s staining and Col1a1/Col3a1 mRNA (fibrosis); and 16S rRNA sequencing (microbiome recovery)
MC activation mechanisms	(1) Techniques: scATAC-seq + phospho-proteomics on sorted MCs; and (2) Targets: PAR2/tryptase, the FcεRI-independent pathway, and NF-κB/AP-1
Human spatial validation	(1) Samples: Ileal/jejunal biopsies (Ranson < 3 vs ≥ 3); (2) Platform: 10 × Visium or GeoMX DSP; and (3) Readouts: MC density, CCL5, and immune infiltrates
Preclinical intervention studies	(1) Drugs: Cromolyn sodium and Maraviroc; and (2) Endpoints: Gut histology, 16S rRNA, cytokines, and 72 hours survival

AP: Acute pancreatitis; MC: Mast cell; LPS: Lipopolysaccharide; IHC: Immunohistochemistry; FITC: Fluorescein isothiocyanate; FACS: Fluorescence-activated cell sorting; IL-6: Interleukin 6; TGF-β: Tumor growth factor β.