Abstract
Epidemiological studies have demonstrated that N-methylnicotinamide (MNA) may exert antithrombotic and anti-inflammatory effects on the endothelium. However, the exact role of MNA in endothelial function remains uncertain. Apolipoprotein E-deficient (apoE(-/-) ) mice fed with a high-fat, high-cholesterol diet (HCD) and human umbilical vein endothelial cells (HUVECs) were used to explore the role of MNA in endothelial function and its underlying mechanism. The endothelium-dependent vasorelaxation to acetylcholine in the aortas of low and high dose MNA-fed apoE(-/-) mice was improved by 24 and 36% (p < 0.05), respectively, compared with high-fat, HCD-fed control. MNA significantly increased nitric oxide/cyclic guanosinemonophosphate levels and decreased asymmetric dimethylarginine (ADMA) concentrations by induction of dimethylarginine dimethylaminohydrolase (DDAH)2 both in aorta and endothelial cells. Neither the activity nor the protein expression of DDAH1 was influenced upon MNA treatment. Then, DDAH2 depletion by RNA interference in HUVECs abolished the protective effect of MNA on endothelial function. Mechanically, this could be attributed to a direct modulation of the methylation level of DDAH2 gene promoter region by MNA. The present study reveals a novel mechanism through which MNA improves endothelial dysfunction and attenuates atherogenesis via the modulation of ADMA-DDAH axis.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
