ABSTRACT
Background and objectives: A recent exploratory study of transcriptional effects of long-term practice of Transcendental Meditation (TM) technologies found evidence for altered expression of genes associated with health and disease. In the present secondary analysis of those data, we test the more specific hypothesis that this sample of long-term practitioners shows a significant reduction in markers of the "Conserved Transcriptional Response to Adversity" (CTRA), an RNA profile characterized by up-regulated inflammation and down-regulated Type I interferon (IFN) activity. Materials and methods: Data come from a previously published study providing genome-wide transcriptional profiles of peripheral blood mononuclear cells (PBMC) from healthy, 38-year practitioners of TM technologies and matched controls (n = 12, mean age 65). The current analysis specifically tests for differential expression of a previously established CTRA indicator gene score, with cross-validation by promoter-based bioinformatic analysis of CTRA-typical differences in transcription factor activity and monocyte subset cellular origins. Results: Compared to controls, the TM group showed lower expression of a pre-specified set of CTRA indicator genes. These effects were accompanied by genome-wide indications of down-regulated pro-inflammatory transcription factor activity (NF-κB, AP-1), up-regulated activity of Interferon Response Factors (IRF) and reduced transcriptional activity of classical monocytes. Conclusions: A sample of long-term practitioners of TM showed reduced CTRA gene expression in PBMC compared to matched controls, supporting the likely value of further research to evaluate causality and specificity of this potential mechanism of health benefits in meditators.
ABSTRACT
Background and Objectives: Stress can overload adaptive mechanisms, leading to epigenetic effects harmful to health. Research on the reversal of these effects is in its infancy. Early results suggest some meditation techniques have health benefits that grow with repeated practice. This study focused on possible transcriptomic effects of 38 years of twice-daily Transcendental Meditation® (TM®) practice. Materials and Methods: First, using Illumina® BeadChip microarray technology, differences in global gene expression in peripheral blood mononuclear cells (PBMCs) were sought between healthy practitioners and tightly matched controls (n = 12, age 65). Second, these microarray results were verified on a subset of genes using quantitative polymerase chain reaction (qPCR) and were validated using qPCR in larger TM and control groups (n = 45, age 63). Bioinformatics investigation employed Ingenuity® Pathway Analysis (IPA®), DAVID, Genomatix, and R packages. Results: The 200 genes and loci found to meet strict criteria for differential expression in the microarray experiment showed contrasting patterns of expression that distinguished the two groups. Differential expression relating to immune function and energy efficiency were most apparent. In the TM group, relative to the control, all 49 genes associated with inflammation were downregulated, while genes associated with antiviral and antibody components of the defense response were upregulated. The largest expression differences were shown by six genes related to erythrocyte function that appeared to reflect a condition of lower energy efficiency in the control group. Results supporting these gene expression differences were obtained with qPCR-measured expression both in the well-matched microarray groups and in the larger, less well-matched groups. Conclusions: These findings are consistent with predictions based on results from earlier randomized trials of meditation and may provide evidence for stress-related molecular mechanisms underlying reductions in anxiety, post-traumatic stress disorder (PTSD), cardiovascular disease (CVD), and other chronic disorders and diseases.
