Sympathetic axonal sprouting induces changes in macrophage populations and protects against pancreatic cancer
Jérémy Guillot, Chloé Dominici, Adrien Lucchesi, Huyen Nguyen, Angélique Puget, Mélanie Hocine, Martha M. Rangel‐Sosa, Milesa Simic, Jérémy Nigri, Fabienne Guillaumond, Martin Bigonnet, Nelson Dusetti, Jimmy Perrot, Jonathan Lopez, Anders Etzerodt, Toby Lawrence, Pierre Pudlo, Florence Hubert, Jean‐Yves Scoazec, Serge A. van de Pavert, Richard Tomasini, Sophie Chauvet, Fanny Mann
Abstract
Abstract Neuronal nerve processes in the tumor microenvironment were highlighted recently. However, the origin of intra-tumoral nerves remains poorly known, in part because of technical difficulties in tracing nerve fibers via conventional histological preparations. Here, we employ three-dimensional (3D) imaging of cleared tissues for a comprehensive analysis of sympathetic innervation in a murine model of pancreatic ductal adenocarcinoma (PDAC). Our results support two independent, but coexisting, mechanisms: passive engulfment of pre-existing sympathetic nerves within tumors plus an active, localized sprouting of axon terminals into non-neoplastic lesions and tumor periphery. Ablation of the innervating sympathetic nerves increases tumor growth and spread. This effect is explained by the observation that sympathectomy increases intratumoral CD163 + macrophage numbers, which contribute to the worse outcome. Altogether, our findings provide insights into the mechanisms by which the sympathetic nervous system exerts cancer-protective properties in a mouse model of PDAC.