Serum TNF-alpha levels are increased and correlate negatively with free IGF-I in Alzheimer disease.
Tumor necrosis factor-alpha (TNF-alpha) and insulin-like growth factor-I (IGF-I) have been involved in the pathogenesis of Alzheimer's disease (AD) as neurotoxic and survival factors, respectively. Recent experimental studies suggest that the signalling pathways of TNF-alpha and IGF-I are functionally interrelated. In order to investigate the possible interaction of TNF-alpha and IGF-I in AD and mild cognitive impairment (MCI), the serum levels of total IGF-I, free IGF-I and TNF-alpha were determined in 141 AD patients, 56 MCI cases and 30 controls. As compared with controls, AD patients showed increased TNF-alpha and decreased IGF-I levels in serum, as well as a significant negative correlation between TNF-alpha and free IGF-I values. MCI patients also exhibited significantly higher TNF-alpha levels than controls. The present results suggest that increased TNF-alpha levels are involved in the pathogenesis of AD and MCI, and might antagonize the neurotrophic activity of IGF-I in these medical conditions. In addition, the combined determination of TNF-alpha and IGF-I might be useful to monitor anti-inflammatory and/or neurotrophic drug effects in AD.
EuroEspes Biomedical Research Center, 15166 A Coruña, Spain. xantonal@yahoo.es <xantonal@yahoo.es>
Antón
A
Alvarez
Ramón
R
Cacabelos
Carolina
C
Sanpedro
Manuel
M
García-Fantini
Manuel
M
Aleixandre
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000378:metabolism*; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000378:metabolism; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D013223:Statistics as Topic; D014409:Tumor Necrosis Factor-alpha / Q000097:blood*
D014409:Tumor Necrosis Factor-alpha; D007334:Insulin-Like Growth Factor I