Fig. 1: Sympathetic remodeling in metaplastic pancreatic lesions requires DCC.

a, Illustration showing the progression of pancreatic ductal adenocarcinoma (PDAC). Acinar cells are the main components of the exocrine pancreas responsible for the production of digestive enzymes. Injury or inflammation causes acinar cells to transdifferentiate into duct-like cells by a process called acinar-to-ductal metaplasia (ADM), which can be identified by markers such as SOX9 or CK19. Metaplasia is a reversible process that allows the regeneration of the pancreatic acinar tissue. However, in the presence of oncogenic Kras mutations, particularly G12D, ADM progresses to pancreatic intraepithelial neoplasia (PanIN) pre-cancerous lesions. PanINs show varying degrees of neoplasia, ranging from low to high-grade carcinoma in situ.

b, Protocol for the induction of ADM in chronic pancreatitis induced by repeated cerulein injections. Green arrows indicate the days of cerulein administration, with mice receiving hourly injections eight times on the treatment day. Samples were collected 2 days after the last cerulein dose.

c-d, Representative immunohistochemistry (IHC) staining for TH (a marker for sympathetic neurons) and F4/80 (a pan-macrophage marker) on sections of the exocrine pancreas from healthy (untreated) mice and cerulein-treated mice. Cerulein-induced metaplasia, identified by SOX9 staining (d’), showed increased sympathetic innervation and macrophage infiltration compared to the adjacent asymptomatic tissue (d) or healthy pancreas. Insets in d’ provide a zoomed-in view of individual staining. DAPI for nuclear staining. Scale bar: 50 μm, 25 μm (insets).

e, Quantification of TH⁺ sympathetic axon density in the exocrine pancreas of healthy mice (H), metaplastic lesions (M), and adjacent exocrine tissue (A) of cerulein-treated mice (Cer). Data are expressed as mean ± SEM. n = 36 ROIs from 6 healthy mice, 44 metaplastic, and 31 adjacent ROIs from 6 cerulein-treated mice. p values indicated (ns: p > 0.05) (Kruskal–Wallis test).

f-g, Representative IHC staining for TH and DCC on sections of the exocrine pancreas from healthy and cerulein-treated mice. DAPI for nuclear staining. Scale bar: 20 μm.

h, Quantification of the ratio of TH⁺ sympathetic axons co-labeled for DCC in healthy (H) and cerulein-treated (Cer) pancreas. Data are presented as mean ± SEM. n = 20 sections from 3 mice per group. p values indicated (unpaired t-test).

i-j, Representative RNAscope in situ hybridization for Th mRNA and Dcc mRNA in sections of the celiac superior mesenteric ganglia (CSMG) of healthy (H) and cerulein-treated mice (Cer). Higher magnification insets highlight individual sympathetic neuronal cell bodies. Scale bars: 20 μm and 5 μm (insets).

k, Quantification of Dcc mRNA (dots) in CSMG sympathetic neurons from healthy (H) and cerulein-treated (Cer) mice. Data are presented as mean ± SEM. n = 9 sections from 3 healthy mice and 8 sections from 3 cerulein-treated mice. p values indicated (unpaired t-test).

l, Experimental design for tamoxifen injection time points and cerulein treatment used in Th-CreERT2–Dcc ^lox/lox and control Cre-negative Dcc^lox/lox mice.

m-n, Representative IHC staining for TH and SOX9 in metaplastic pancreatic lesions (m’ and n’) and adjacent exocrine tissue (m and n) of cerulein-treated control and Th-CreERT2–Dcc ^lox/lox mice. DAPI for nuclear staining. Scale bar: 25 μm.

o, Quantification of TH⁺ sympathetic axon density in metaplastic pancreatic lesions (M) and adjacent tissues (A) of cerulein-treated control (ctr) and Th-CreERT2–Dcc ^lox/lox (cKO) mice. Data are presented as mean ± SEM. n = 21 metaplastic and 11 adjacent ROIs from 3 control mice; 23 metaplastic and 12 adjacent ROIs from 3 cKO mice. p values indicated (ns: p > 0.05) (Kruskal–Wallis test).