Increased oxidative stress impairs adipose tissue function in sphingomyelin synthase 1 null mice

Area of Science:

• Biochemistry
• Metabolic diseases
• Cell biology

Background:

• Sphingomyelin synthase 1 (SMS1) converts ceramide to sphingomyelin.
• SMS1's role in adipose tissue and its link to metabolic dysfunction are not fully understood.

Purpose of the Study:

• To investigate the function of SMS1 in white adipose tissue (WAT).
• To determine the impact of SMS1 deficiency on metabolic health and oxidative stress.

Main Methods:

• Analysis of SMS1 null mice and wild-type littermates.
• Assessment of plasma lipids, lipoprotein lipase (LPL) activity, and fatty acid uptake in WAT and liver.
• Evaluation of oxidative stress markers, gene expression, ATP content, and mitochondrial respiratory chain complexes in WAT.
• Treatment of mutant mice with N-acetyl cysteine (NAC).

Main Results:

• SMS1 null mice exhibited a lipodystrophic phenotype with reduced WAT and elevated plasma triglycerides.
• Fatty acid uptake in WAT was decreased in SMS1 null mice, accompanied by reduced LPL activity.
• WAT from mutant mice showed significant oxidative stress, altered gene expression (apoptosis, redox, mitochondrial stress), reduced ATP, and impaired mitochondrial function.
• NAC treatment partially reversed lipodystrophy and normalized triglyceride levels.

Conclusions:

• SMS1 is essential for maintaining WAT function and preventing oxidative stress.
• SMS1 deficiency leads to WAT damage and contributes to metabolic dysfunction.
• Targeting oxidative stress may offer therapeutic potential for SMS1-related metabolic disorders.