Cheol-Gu Lee

The gene expression profile of the aging process was analyzed in skeletal muscle of mice. Use of high-density oligonucleotide arrays representing 6347 genes revealed that aging resulted in a differential gene expression pattern indicative of a marked stress response and lower expression of metabolic and biosynthetic genes. Most alterations were either completely or partially prevented by caloric restriction, the only intervention known to retard aging in mammals. Transcriptional patterns of calo

To provide a global analysis of gene expression in the aging heart, we monitored the expression of 9,977 genes simultaneously in 5- and 30-month-old male B6C3F(1) mice by using high-density oligonucleotide microarrays and several statistical techniques. Aging was associated with transcriptional alterations consistent with a metabolic shift from fatty acid to carbohydrate metabolism, increased expression of extracellular matrix genes, and reduced protein synthesis. Caloric restriction (CR) starte

To investigate the effects of electro-acupuncture (EA) treatment on regions remote from the application, we measured cellular, enzymatic, and transcriptional activities in various internal tissues of healthy rats. The EA was applied to the well-identified acupoint ST36 of the leg. After application, we measured the activity of natural killer cells in the spleen, gene expression in the hypothalamus, and the activities of antioxidative enzymes in the hypothalamus, liver and red blood cells. The EA

Rapamycin (RM), a drug that inhibits the mechanistic target of rapamycin (mTOR) pathway and responds to nutrient availability, seemingly mimics the effects of caloric restriction (CR) on healthy life span. However, the extent of the mechanistic overlap between RM and CR remains incompletely understood. Here, we compared the impact of CR and RM on cellular metabolic status. Both regimens maintained intracellular ATP through the chronological aging process and showed enhanced mitochondrial capacit

To characterize gene expression that is dependent on the strength of calorie restriction (CR), we obtained transcriptome at different levels of glucose, which is a major energy and carbon source for budding yeast. To faithfully mimic mammalian CR in yeast culture, we reconstituted and grew seeding yeast cells in fresh 2% YPD media before inoculating into 2%, 1%, 0.5% and 0.25% YPD media to reflect different CR strengths. We collected and characterized 160 genes that responded to CR strength base

Mitochondria play a crucial role in eukaryotic cells; the mitochondrial electron transport chain (ETC) generates adenosine triphosphate (ATP), which serves as an energy source for numerous critical cellular activities. However, the ETC also generates deleterious reactive oxygen species (ROS) as a natural byproduct of oxidative phosphorylation. ROS are considered the major cause of aging because they damage proteins, lipids, and DNA by oxidation. We analyzed the chronological life span, growth ph

Caloric restriction (CR) has been shown to extend lifespan and prevent cellular senescence in various species ranging from yeast to humans. Many effects of CR may contribute to extend lifespan. Specifically, CR prevents oxidative damage from reactive oxygen species (ROS) by enhancing mitochondrial function. In this study, we characterized 33 single electron transport chain (ETC) gene-deletion strains to identify CR-induced chronological lifespan (CLS) extension mechanisms. Interestingly, defects