Tumor necrosis factor alpha: a key component of the obesity-diabetes link.
Recent data have suggested a key role for tumor necrosis factor (TNF)-alpha in the insulin resistance of obesity and non-insulin-dependent diabetes mellitus (NIDDM). TNF-alpha expression is elevated in the adipose tissue of multiple experimental models of obesity. Neutralization of TNF-alpha in one of these models improves insulin sensitivity by increasing the activity of the insulin receptor tyrosine kinase, specifically in muscle and fat tissues. On a cellular level, TNF-alpha is a potent inhibitor of the insulin-stimulated tyrosine phosphorylations on the beta-chain of the insulin receptor and insulin receptor substrate-1, suggesting a defect at or near the tyrosine kinase activity of the insulin receptor. Given the clear link between obesity, insulin resistance, and diabetes, these results strongly suggest that TNF-alpha may play a crucial role in the systemic insulin resistance of NIDDM. This may allow for new treatments of disorders involving resistance to insulin.
Hotamisligil
G S
GS
Dana-Farber Cancer Institute, Boston, Massachusetts 02115.
Spiegelman
B M
BM
D000273:Adipose Tissue / Q000503:physiopathology; D000818:Animals; D003920:Diabetes Mellitus / Q000503:physiopathology*; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology; D009765:Obesity; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology*
D014409:Tumor Necrosis Factor-alpha