Tissue, Species, and Environmental Differences in Absolute Quantities of Murine mRNAs Coding for Alpha, Mu, Omega, Pi, and Theta Glutathione S-Transferases

Abstract

This article reports the first absolute quantitative analysis of expression patterns of murine transcripts ( Gsta1/2, Gsta3, Gsta4, Gstm1, Gstm2, Gstm3, Gsto1, Gstp1/2, Gstt1, Gstt2) coding for most glutathione S-transferases (GSTs) of alpha, mu, omega, pi, and theta classes. We examine how the steady-state numbers of transcripts are modulated in association with: three animal organs (liver, kidney, and lung) where extensive detoxification occurs; two species ( Mus musculus and Mus spretus) representing common laboratory and aboriginal mice; and two genetic and animal living conditions (wild-derived inbred animals and free-living mice). Moreover, quantitations performed examine how the pulmonary steady-state Gst mRNA amounts are affected in M. musculus by paraquat (a superoxide generator), and in M. spretus by dwelling at a polluted area. The results point to complex tissue-, species-, and life condition-dependent expression of the investigated transcripts. Among others, they show: i) the ubiquity of most transcripts, except Gstm3 mRNA that was virtually absent or at very low amounts (≤0.001 molecules/pg) in kidney and lung of M. spretus; ii) unique expression profiles for each transcript and mouse organ examined; iii) outstanding species-specific differences in basal amounts of most Gst mRNAs, this effect being most apparent in the case of Gsta1/2, Gsta3, Gstm2, Gsto1, Gstt1, and Gstt2; iv) paraquat-induced upregulation of most Gst mRNAs, with the notable exception of those coding for theta class GSTs; v) a tendency for mice dwelling at a wildlife reserve of having lower and more homogeneous Gsta3 mRNA levels than those collected in an anthropogenic environment.