Premium
STRESS AND SURVIVAL: POSSIBLE ROLE OF SIRT1 IN THE DIENCEPHALON DURING FASTING
Author(s) -
Sirivelu Madhu P,
Metzger Shana,
MohanKumar Puliyur S,
Ramachandran Ramesh
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.a1470-c
Subject(s) - diencephalon , endocrinology , medicine , messenger rna , caloric theory , biology , sirt2 , neuroprotection , hypothalamus , adipose tissue , endogeny , dopamine , nad+ kinase , sirtuin , gene , biochemistry , enzyme
Sirtuins (SIRT), a novel family of NAD‐dependent deacetylases, is known to mediate caloric restriction‐induced extension of life span. They have also been implicated in preventing oxidative damage during stress, thus conferring neuroprotection during times of adversity. Alternate day fasting has been shown to equal or better most beneficial effects observed with caloric restriction. We hypothesized that fasting‐induced beneficial effects could also be mediated through alterations in SIRT1 expression. To investigate this hypothesis, we fasted sexually mature female chicken (Hyline W36 strain) for 48 h. The diencephalon of the brain, which includes the hypothalamus, is known to mediate several of the beneficial effects of caloric restriction. We harvested the diencephalon and other non‐neuronal tissues such as the liver, pituitary and adipose tissue. SIRT1 mRNA expression was measured in these tissues using quantitative real time‐PCR. Fasting induced a significant increase (0.006±0.000025; p<0.05) in the relative SIRT1 mRNA expression normalized to β‐actin in the diencephalon when compared to ad‐libitum fed controls (0.004±0.000024). In contrast, SIRT1 mRNA expression decreased significantly in adipose tissue of fasted chicken compared to the controls. Fasting did not affect SIRT‐1 mRNA expression in the liver and pituitary. It is concluded that fasting‐induced augmentation of SIRT‐1 mRNA expression in the diencephalon might play a role in mediating the beneficial effects of fasting.