A brief bout of exercise alters gene expression and distinct gene pathways in peripheral blood mononuclear cells of early- and late-pubertal females

Abstract

Recent studies show that brief exercise alters circulating neutrophil and peripheral blood mononuclear cell (PBMC) gene expression, ranging from cell growth to both pro-and anti-inflammatory processes. These initial observations were made solely in males, but whether PBMC gene expression is altered by exercise in females is not known. Ten early-pubertal girls (8-11 yr old) and 10 late-pubertal girls (15-17 yr old) performed ten 2-min bouts of cycle ergometry ( approximately 90% peak heart rate) interspersed with 1-min rest intervals. Blood was obtained at rest and after exercise, and microarrays were performed in each individual subject. RNA was hybridized to Affymetrix U133+2.0 Arrays. Exercise induced significant changes in PBMC gene expression in early (1,320 genes)- and late (877 genes)-pubertal girls. The expression of 622 genes changed similarly in both groups. Exercise influenced a variety of established gene pathways (EASE < 0.04) in both older (6 pathways) and younger girls (11 pathways). Five pathways were the same in both groups and were functionally related to inflammation, stress, and apoptosis, such as natural killer cell-mediated cytotoxicity, antigen processing and presentation, B cell receptor signaling, and apoptosis. In summary, brief exercise alters PBMC gene expression in early- and late-pubertal girls. The pattern of change involves diverse genetic pathways, consistent with a global danger-type response, perhaps readying PBMCs for a range of physiological functions from inflammation to tissue repair that would be useful following a bout of physical activity.

Fig. 1.

Assessment of exercise intensity during the ten 2-min bouts used to gage the peripheral blood mononuclear cell (PBMC) genomic response in early (white bars)- and late (gray bars)-pubertal girls. The values represent the means ± SE of heart rate, work rate, and oxygen uptake (V̇o₂) expressed as percentage of the individual participant's peak values obtained in an earlier session from the progressive exercise protocol. As can be seen, the relative exercise intensity was virtually the same in the 2 groups. Lactate increased in both groups (*P < 0.05)

Fig. 2.

Effect of exercise on PBMCs in the early and late pubertal girls. Data represent the means ± SE before (white bars) and immediately after exercise (gray bars) for all leukocytes, lymphocytes, and monocytes. Hatched bars represent the late-pubertal girls. *Significant (P < 0.05) increase from before to after exercise.

Fig. 3.

Comparison of the effect of exercise on PBMC genes in early- and late-pubertal girls, showing the relative magnitude of the effect (circles) and the size of the overlap (shaded area). There were 622 PBMC genes that were significantly altered by exercise in both groups. Tables S1–S3 are available with the online version of this article.

Fig. 4.

Comparison of fold change in 622 PBMC genes that were significantly affected by exercise in both the early- and late-pubertal girls. Data points represent the mean fold change for each of the exercise-sensitive genes in both groups. The fold change in the 2 groups was highly correlated (r = 0.98).