Insulin >>> Cell Proliferation

[Guest guest]

This is an interesting paper:

Exp Gerontol. 2003 Jun;38(6):631-9.

" An in vitro model of caloric restriction. "

de Cabo R, Furer-Galban S, Anson RM, Gilman C, Gorospe M, Lane MA.

Laboratory of Experimental Gerontology, National Institute on Aging-

Intramural Research Program, National Institutes of Health, 5600

Shock Drive, Baltimore, MD 21224-6825, USA.

" The mechanisms underlying the ability of caloric restriction (CR) to

extend life span and enhance stress responsiveness remain elusive.

Progress in this area has been slow due to the complexities of using

animals for CR studies and assessing life span as the measure of CR

effectiveness. It is therefore of great interest to develop in vitro

models of CR. Here we use sera obtained from either Fisher 344 rats

or Rhesus monkeys that were fed ad libitum (AL) or CR diets to

culture various cell types. We show that treatment of cultured cells

with CR sera caused reduced cell proliferation, enhanced tolerance to

oxidants and heat, and heightened expression of stress-response

genes. These phenotypic features mirror the effects of CR in animals.

Supplementation of CR serum with insulin and insulin-like growth

factor (IGF)-1 partially restored the proliferative and stress-

response phenotype that was seen in cells cultured with AL serum,

indicating that reduced levels of insulin and IGF-1 likely contribute

to the CR-related effects. This in vitro cell culture model

recapitulates key in vivo proliferative and stress-response

phenotypic features of CR, and further suggests that endocrine

mechanisms contribute to the enhanced stress responsiveness observed

in CR animals. "

PMID: 12814798

Rodney.