Gene expression changes reveal patterns of aging in the rat digestive tract

Similarly to other organs, the human digestive system is adversely affected by aging presenting physiologic manifestations that include compromised absorption and secretion, decreased motility, weakened mucosal barrier and as well as a high incidence of colon cancer. As biomedical advances enable the population to live longer, our understanding of molecular events that govern aging and disease states is enhanced through methodical analyses of temporal tissue-specific gene expression profiles. Recently, DNA microarray analyses have been employed to examine age-associated transcriptional profiles in the mammalian digestive tract. Gene expression patterns revealed that the magnitude and trend of age-associated changes differ in the rat colon and duodenum. Interestingly, the expression of genes involved in energy-generating metabolic pathways was decreased in the duodenum and increased in the colon. Microarray analyses detected modulations in expression of genes associated with compromised intestinal function and propensity for colon cancer in the aged population. Furthermore, altered expression was observed for certain genes implicated in governance of aging and lifespan in other organisms suggesting intriguing commonalities across species. Thus, these studies demonstrated feasibility and usefulness of DNA microarrays for identifying pathways involved in the molecular pathophysiology of the aging process and lifespan control in complex organisms.