Wound healing in periodontal disease induces macrophage polarization characterized by different arginine-metabolizing enzymes

In this study, we used ligature-removal periodontitis healing mouse model and demonstrated for the first time that inducible nitric oxide synthase (iNOS) and arginase-1 (Arg-1), arginine-metabolizing enzymes with contrasting functions, reflect the inflammation and healing responses in periodontal tissues through polarity switching of the macrophage phenotype. Briefly, iNOS expression increased during the progression phase, whereas Arg-1 expression increased during the healing phase.