Correlation of gene expression with physiological functions: Examples of pulmonary blood vessel rheology, hypoxic hypertension, and tissue remodeling

Microarray gene chip technology is a powerful invention looking for applica tions. A general principle is proposed here to direct the power of the tech nology toward physiology, medicine, and pharmacology. Our principle is to m atch quantitative measures of gene expression with the trend of mathematica l parameters that describe biological functions. Mathematical parameterizat ion is the heart. The procedure is illustrated by lung physiology, includin g the hypoxic hypertension, rheological properties of the tissues, and the remodeling of the pulmonary arterial wall under hypertensive stress. We sho w first how to reduce the experimental results on these physiological funct ions into mathematical formulas, and how the parameters of these formulas d escribe the functional trends precisely. Then under the assumption that the microarray reveals gene activities quantitatively, we match the trends of the gene activity with the trends of the functional parameters. Genes whose trends do match are interpreted as relevant to the functions. Those that d o not match are considered irrelevant to the functions. The more functions we consider, the fewer will be the number of genes that are relevant to all functions. Thus we learn about the generality and specificity of the influ ence of genes on physiology.