In this symposium, we introduce our recent studies regarding new actions of diet-derived nitric oxide (NO) and bone marrow-derived NO. 
A new pathway in which NO is synthesized from NO metabolites; nitrite and nitrate (NOx), is recently discovered. However, whether dietary NOx deficiency causes diseases remains to be clarified. We demonstrated that long-term low NOx diet caused metabolic syndrome, vascular dysfunction, and cardiovascular death in mice. These results indicate that dietary NOx plays a pivotal role in the prevention of those disorders (Diabetologia 2017).
NO, synthesized by NOSs (nNOS, iNOS, and eNOS), plays a role in the development of pulmonary hypertension. However, the role of NO/NOSs in bone marrow cells in pulmonary hypertension remains elusive. We showed that transplantation of n/i/eNOSs-deficient bone marrow significantly aggravated hypoxia-induced pulmonary hypertension in wild-type mice, and transplantation of wild-type bone marrow significantly ameliorated hypoxia-induced pulmonary hypertension in n/i/eNOSs-deficient mice. These results show that myelocytic n/i/eNOSs play a crucial protective role in the pathogenesis of pulmonary hypertension (Am J Respir Crit Care Med 2018).