NOS2

NOS2 Full Name

nitric oxide synthase 2, inducible

NOS2 Introduction

Nitric oxide synthase is a key enzyme that catalyzes the production of nitric oxide (NO) from L-arginine, and participates in the defense against pathogens in the immune system by regulating macrophage polarization. This enzyme is associated with dysfunction of hepatic sinusoidal endothelial cells in non-alcoholic steatohepatitis, forming a vicious cycle through NO production and oxidative stress. Research has shown that NOS activation involves the NF κ B signaling pathway, and its product NO participates in the bone destruction process of psoriatic arthritis through the TNF α - IL-17 axis. The 2024 study revealed for the first time a new mechanism by which NOS regulates vascular inflammation through Septin2 thiol nitrosylation modification. In macrophage immunity against pathogens, the NOS mediated L-arginine metabolic pathway is the core link for interferon IFN - γ to activate macrophages [M (IFN - γ)]. The NO generated by NOS catalysis exerts direct bactericidal effect by forming peroxynitrite anions, while regulating Th1 type immune response.

Figure. Structure of nitric oxide synthase.

Related Diseases
1. Psoriatic arthritis: GWAS studies suggest that mutations in the NOS2 gene are associated with genetic susceptibility. iNOS promotes osteoclast differentiation through the TNF α - dependent pathway, and its expression level is positively correlated with the inflammatory cytokine network in synovial tissue.
2. Cardiovascular disease: During the formation of atherosclerotic plaque, inflammatory mediators induce abnormal activation of iNOS through NF-κB pathway.
3. Neurological injury: iNOS mediated neurotoxic NO production during cerebral ischemia-reperfusion is a key mechanism in stroke.

Nitric oxide synthase 2 (NOS2) is a member of the nitric oxide synthase family, responsible for synthesizing nitric oxide (NO), a crucial gas signaling molecule. As the name suggests, NOS2 is known for its strict transcriptional regulation; It is not constitutively expressed in most cells, but is induced by pro-inflammatory cytokines (such as interleukin-1 β, tumor necrosis factor - α, interferon - γ) and microbial products. Its main physiological function is innate immune defense, where it produces large and sustained amounts of NO to combat pathogens. However, in a wide range of autoimmune, chronic inflammatory, and degenerative diseases, its dysregulation or chronic expression is a key driving factor for pathological inflammation and tissue damage.

Alternate Names for NOS2

NOS2; nitric oxide synthase 2, inducible; iNOS; Nos-2; Nos2a; i-NOS; NOS-II; nitric oxide synthase, inducible; MAC-NOS; NOS type II