Neuronatin Is Associated with an Anti-Inflammatory Role in the White Adipose Tissue

Neuronatin (NNAT) is known to regulate ion channels during brain development and plays a role in maintaining the structure of the nervous system. A previous in silico analysis showed that Nnat was overexpressed in the adipose tissue of an obese rodent model relative to the wild type. Therefore, the aim of the present study was to investigate the function of Nnat in the adipose tissue. Because obesity is known to systemically induce low-grade inflammation, the Nnat expression level was examined in the adipose tissue obtained from C57BL/6 mice administered lipopolysaccharide (LPS). Unexpectedly, the Nnat expression level decreased in the white adipose tissue after LPS administration. To determine the role of NNAT in inflammation, 3T3-L1 cells overexpressing Nnat were treated with LPS. The level of the p65 subunit of nuclear factor-kappa B (NF-κB) and the activity of NF-κB luciferase decreased following LPS treatment. These results indicate that NNAT plays an anti-inflammatory role in the adipose tissue.