Characterization of the peripheral blood transcriptome in a repeated measures design using a panel of healthy individuals

Abstract

A repeated measures microarray design with 22 healthy, non-smoking volunteers (aging 32±5years) was set up to study transcriptome profiles in whole blood samples. The results indicate that repeatable data can be obtained with high within-subject correlation. Probes that could discriminate between individuals are associated with immune and inflammatory functions. When investigating possible time trends in the microarray data, we have found no differential expression within a sampling period (within-season effect). Differential expression was observed between sampling seasons and the data suggest a weak response of genes related to immune system functioning. Finally, a high number of probes showed significant season-specific expression variability within subjects. Expression variability increased in springtime and there was an association of the probe list with immune system functioning. Our study suggests that the blood transcriptome of healthy individuals is reproducible over a time period of several months.

Effects of genetic and early environmental risk factors for depression on serotonin transporter expression and methylation profiles

“…Sustained alterations in SERT expression profiles may in turn relate to changes in serotonergic functioning and thus constitute a possible molecular pathway mediating disease vulnerability as a function of GxE. In accordance with genome-wide transcriptomics analyses, 46,47 preliminary evidence from our pilot study suggests that interindividual variability in SERT expression is substantially higher compared with intraindividual variation, thus highlighting the potential usefulness of this specific transcript as a biomarker. Although not without inconsistencies, 75, 76, 77 numerous studies indeed suggest that lower SERT expression in the brain and periphery associates with major depression, 14, 15, 16 treatment efficacy 14,78,79 and increased stress sensitivity.…”

“…Prior studies have generally confirmed a considerable intraindividual stability of genome-wide gene expression patterns over hours and months; however, they have also highlighted that stability varies across individual transcripts. 46,47 As intra- and interindividual variation in human SERT mRNA expression has, to the best of our knowledge, not explicitly been evaluated yet, we further conducted a small pilot study investigating respective patterns.…”

Genome-Wide Changes in Peripheral Gene Expression following Sports-Related Concussion

“…The concussed athlete, but not the uninjured teammate control, underwent repeat phlebotomy at the sub-acute time-point. Because prior studies have demonstrated the stability of gene transcription profiles among healthy adults sampled at intervals ranging from 1 week 15 to several months, 16 it was assumed that the mRNA expression among uninjured control athletes would not change significantly over the 6 days spanning the acute-to-sub-acute time period. Unlike the injured athletes, who ceased all physical exertion after concussion, there was no change in the exertional activities of controls between the acute and subacute time-points.…”

RNA-Seq analysis of seasonal and individual variation in blood transcriptomes of healthy managed bottlenose dolphins

“…Further development of blood transcriptomics as a tool for identifying signatures indicative of disease, exposures, or health status in wildlife requires knowledge of both the natural intra- and inter-animal variation in gene expression. For example, longitudinal studies of gene expression in human blood have found minimal intra-individual variation over the course of 1 month, but significant variability was observed by 3 to 6 months and this baseline variation must be taken into account [ 8 , 9 ]. Recent studies suggest that seasonal patterns in human behavior, physiology, and disease susceptibility may be related to underlying fluctuations in hematological parameters, as blood cell composition shows annual variation [ 10 ].…”