Nmes1 is a novel regulator of mucosal response influencing intestinal healing potential.

The initiation of tissue remodeling following damage is a critical step in preventing the development of immune-mediated diseases. Several factors contribute to mucosal healing, leading to innovative therapeutic approaches for managing intestinal disorders. However, uncovering alternative targets and gaining mechanistic insights are imperative to enhance therapy efficacy and broaden its applicability across different intestinal diseases. Here we demonstrate that Nmes1, encoding for Normal Mucosa of Esophagus-Specific gene 1, also known as Aa467197, is a novel regulator of mucosal healing. Nmes1 influences the macrophage response to the tissue remodeling cytokine IL-4 in vitro. In addition, using two murine models of intestinal damage, each characterized by a type 2-dominated environment with contrasting functions, the ablation of Nmes1 results in decreased intestinal regeneration during the recovery phase of colitis, while enhancing parasitic egg clearance and reducing fibrosis during the advanced stages of Schistosoma mansoni infection. These outcomes are associated with alterations in CX3CR1+ macrophages, cells known for their wound-healing potential in the inflamed colon, hence promising candidates for cell therapies. All in all, our data indicate Nmes1 as a novel contributor to mucosal healing, setting the basis for further investigation into its potential as a new target for the treatment of colon-associated inflammation.

Apoptotic cell signals and heterogeneity in macrophage function: Fine-tuning for a healthy liver.

Functional heterogeneity in tissue macrophage populations has often been traced to developmental and spatial cues. Upon tissue damage, macrophages are exposed to soluble mediators secreted by activated cells, which shape their polarisation. Interestingly, macrophages are concomitantly exposed to a variety of different dying cells, which carry miscellaneous signals and that need to be recognised and promptly up-taken by professional phagocytes. This review discusses how differences in the nature of the dying cells, like their morphological and biochemical features as well as the specificity of phagocytic receptor usage on macrophages, might contribute to the transcriptional and functional heterogeneity observed in phagocytic cells in the tissue.