A reverse genetics cell-based evaluation of genes linked to healthy human tissue age

Abstract

We recently developed a binary (i.e., young vs. old) classifier using human muscle RNA profiles that accurately distinguished the age ofmultiple tissue types. Pathway analysis did not reveal regulators of these 150 genes, so we used reverse genetics and pharmacologic methods to explore regulation of gene expression. Using small interfering RNA, well-studied age-related factors (i.e., rapamycin, resveratrol, TNF-a, and staurosporine), quantitative real-timePCRand clustering analysis,westudiedgene-gene interactions inhumanskeletalmuscle andrenal epithelial cells. Individual knockdown of 10 different age genes yielded a consistent pattern of gene expression in muscle and renal cells, similar to in vivo. Potential epigenetic interactions included HIST1H3E knockdown, leading to decreased PHF19 and PCDH9, and increased ICAM5 in muscle and renal cells, while ICAM5 knockdown reduced HIST1H3E expression. Resveratrol, staurosporine, and TNF-a significantly regulated the in vivo aging genes, while only rapamycinperturbed thehealthy-age gene expression signature in amanner consistentwith in vivo. In vitro coordination of gene expression for this in vivo tissue age signature indicates a degree of direct coordination, andthe observed linkwith mTORactivity suggests a direct link between a robust biomarker of healthy neuromuscular age and a major axis of life span inmodel systems.-Crossland, H.,Atherton, P. J.,Stromberg,A.,Gustafsson,T.,Timmons, J.A.Areversegenetics cell-based evaluation of genes linked to healthy human tissue age. FASEB J. 31, 96-108 (2017). www.fasebj.org.