Endothelial nitric oxide synthase in the vascular wall: Mechanisms regulating its expression and enzymatic function

Association of endothelial nitric oxide synthase (NOS3) rs2070744 variant with advanced retinopathy of prematurity: a case-control study and meta-analysis

Despite advances in neonatal and ophthalmological care, retinopathy of prematurity (ROP) continues to be a leading cause of childhood blindness worldwide. Investigating gene variants associated with vascular responses in ROP may provide valuable insights into its pathogenesis and identify risk or protective factors. Nitric oxide (NO) and endothelin-1 (ET-1) play roles in vascular regulation, influencing processes relevant to ROP development. Functional variants of genes encoding endothelial NO sythetase (NOS3 rs1799983, rs2070744), endothelin-1 (EDN1 rs5370), and endothelin receptor A (EDNRA rs5335) may influence ROP development or progression. The results of our study support the role of the rs2070744 variant in ROP. We identified the protective effect of the rs2070744C allele against the development of ROP requiring treatment, also after adjusting for covariates. Meta-analysis including 298 patients and 397 controls confirmed this protective role. The rs2070744CC homozygous genotype exhibited an odds ratio (OR) of 0.42 (adjusted P = 0.036). Additional meta-analysis results for NOS3 rs1799983 are presented, suggesting potential risk in a recessive model. No associations were found between EDN1, EDNRA variants, and ROP. Exploring genetic predispositions in ROP, including vascular regulation genes, can lead to personalized prevention and treatment approaches. Our results need to be replicated in a larger sample of premature infants.

Potential role of eNOS and EDN-1 gene polymorphisms in the development and progression of retinopathy of prematurity

The aim of this study was to investigate the association between selected polymorphisms of nitric oxide synthetase (eNOS) and endothelin-1 (EDN-1) with the occurrence and progression of retinopathy of prematurity (ROP). A prospective study was conducted on 90 preterm infants (44 female), comparing 39 cases with ROP and 51 controls without ROP. Patients who developed ROP were further divided into two subgroups-those with spontaneous regression of the disease and those with ROP requiring treatment. We found that preterm infants with TT genotype eNOS 894G > T had a 12.8-fold higher risk of developing ROP requiring treatment (p = 0.02). Our results showed that allele T of eNOS894G > T polymorphism was significantly more prevalent in ROP patients requiring treatment (p = 0.029). We also investigated preterm infants with TC genotype eNOS - 786 T > C and found an 8.8-fold higher risk developing of ROP requiring treatment (p = 0.021). Our results didn't show any association between EDN-1 5665G > T polymorphism and ROP development. The eNOS polymorphisms appears to influence incidence of ROP requiring treatment in preterm infants. Future research on single nucleotide polymorphisms may provide important information about the pathogenetic mechanisms underlying the development of ROP.

Protective effects of Guanxin Shutong capsule drug-containing serum on tumor necrosis factor-α-induced endothelial dysfunction through nicotinamide adenine dinucleotide phosphate oxidase and the nitric oxide pathway

The Chinese medicinal formula Guanxin Shutong capsule (GXSTC) has been used for almost 10 years as a clinical treatment for chest pain, depression, palpitation and cardiovascular diseases. The aim of this study was to investigate the effects of GXSTC drug-containing serum on tumor necrosis factor-α (TNF-α)-stimulated endothelial cells. Cell viability was measured by MTT assay, and nitric oxide (NO) levels and NO synthase (NOS) activity were measured as standards of endothelial dysfunction. Malondialdehyde (MDA) levels and superoxide dismutase (SOD) activity were evaluated using commercial kits. In addition, the protein expression of endothelial NOS (eNOS), AKT and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunits was examined to evaluate the effect of GXSTC drug-containing serum on ECV304 cells. GXSTC significantly reversed the decrease in NO production induced by TNF-α (5 ng/ml) in ECV304 cells. The expression of NADPH oxidase subunits was increased by TNF-α treatment, but markedly inhibited by treatment with GXSTC in TNF-α-stimulated cells. In summary, GXSTC increased the production of NO in ECV304 cells and exerted a protective effect on ECV304 cells stimulated with TNF-α by upregulating the mRNA and protein expression of eNOS. This was accompanied by increased SOD activity and reduced MDA levels. These results suggested that GXSTC protects the endothelium via the NO pathway and exhibits antioxidant effects.