eNOS phosphorylation on serine 1176 affects insulin sensitivity and adiposity

Area of Science:

• Biochemistry
• Physiology
• Metabolic Research

Background:

• Endothelial nitric oxide synthase (eNOS) activity is regulated by phosphorylation.
• The S1176 phosphorylation site is critical for eNOS function.
• Understanding eNOS phosphorylation's role in metabolism is crucial.

Purpose of the Study:

• To investigate the role of eNOS phosphorylation at S1176 in vivo.
• To determine the impact of specific eNOS mutations on vascular and metabolic functions.
• To explore eNOS as a potential therapeutic target for metabolic disorders.

Main Methods:

• Generation of knockin mice with phosphomimetic (SD) and unphosphorylatable (SA) eNOS mutations at S1176.
• Assessment of vascular reactivity and endothelial nitric oxide (NO) production.
• Evaluation of metabolic parameters including insulin sensitivity, adiposity, and weight gain on high-fat diet.

Main Results:

• The SA mutation led to hypertension, decreased vascular reactivity, insulin resistance, hyperinsulinemia, increased adiposity, and weight gain.
• The SD mutation increased basal and stimulated NO production, decreased insulin levels, and conferred resistance to high-fat-induced weight gain.
• S1176 phosphorylation significantly influences both vascular function and systemic metabolism.

Conclusions:

• eNOS phosphorylation at S1176 plays a critical role in regulating insulin sensitivity, energy metabolism, and body weight.
• Targeting eNOS phosphorylation offers a novel therapeutic strategy for obesity and insulin resistance.
• These findings highlight the interconnectedness of vascular health and metabolic regulation via eNOS.