Epigenetic immune-modulation by Histone Deacetylase Activity (HDAC) of tissue and organ regeneration in Xenopus laevis

In the present work we propose to shed light on the epigenetic control of immune mechanisms involved during Xenopus tail regeneration. Here we show that the first 24 hour post amputation (hpa), which exclusively encompasses the first wave of myeloid differentiation, are crucial to epigenetically modulate the regenerative ability of Xenopus tadpoles. During this developmental window, HDAC activity was shown to be necessary for the proper establishment of myeloid cells dynamics in the regenerative bud, mainly contributing to modulate the behavior of monocytes/macrophages and neutrophils as well the mRNA expression pattern of the main myeloid markers, such as LURP, MPOX, Spib and mmp7. In addition, we functionally bridge the spatial and temporal dynamics of lipid droplets, the main platform of lipid mediators synthesis in myeloid cells during the inflammatory response, and the regenerative ability of Xenopus tadpoles showing that 15-LOX activity is a key player during tail regeneration. Taken together our results support a role for the epigenetic control of inflammatory response during tissue and organ regeneration, which may positively impact translational approaches for regenerative medicine.