Neuroimmunomodulation in chronic wounds healing after treatment with photodynamic therapy: the Role of iNOS.

"Neuroimmunomodulation" defines the modulatory role of the nervous system in relation to immune functions, which reflects part of the bidirectional communication between the nervous system and the immune system. This phenomenon is possible due to the existence of receptors for neurotransmitters (for example norepinephrine or acetylcholine) on immune cells. In fact, these molecules are able to direct and modulate many of the events of the wound healing process. Among these we find nitric oxide (NO): neuromodulator involved in the control of vascular tone and blood pressure, which has a vasodilator and antimicrobial effect. Photodynamic treatments in venous leg ulcers have shown how this treatment stimulates the activity of immune cells involved in healing, which have, among their functions, that of releasing NO into the extracellular space. The experimental results, showed an increase in the expression of iNOS in PDT-treated lesions, underlining its central role in improving the clinical condition of the wound. Furthermore, these results can be associated with the same studies carried out on other neuromediators, confirming the neuroimmunomodulatory role of NO. Since INOS is almost ubiquitous, its over-expression can be observed in almost all tissues: this not only makes it easily detectable, but any treatments based on its capabilities could be valid on many tissues. In the light of such evidence, the versatility of this protein would therefore assume a key role in the definition of new clinical therapies, as well as in the study of the process of wound healing itself.