Impact of meditation on gene exoression and their methylation
Thirty experienced meditators and 30 age- and gender-matched non-mediators participated in this case-control study. RNA and DNA were extracted from blood samples. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) with GAPDH normalization was used to measure the expression of eight inflammation-related genes (IFNG, IL6, CCL2, CCR7, TNF, NFKB1, CXCL8, and PTGS2). Additionally, bisulfite-specific PCR and Sanger sequencing were performed to assess the methylation status of five of these genes (IL6, TNF, IFNG, PTGS2, and CXCL8) in their promoter regions. The mean age of participants was 43.83 ± 9.92 years, and 63.34% in each group were male. Compared to controls, meditators showed significantly lower relative gene expression for IFNG (Fold change (FC)=7, p=0.045), IL6 (FC=3.6, p=0.045), TNF (FC=2.73, p=0.038), NF?B1 (FC=3.2, p=0.045), CXCL8 (FC=3.3, p=0.047), and PTGS2 (FC=9.5, p=0.013). Furthermore, meditators exhibited significantly higher promoter region methylation in IL6 (p < 0.001) and CXCL8 (p = 0.001). The methylation level at specific CpG sites showed that four out of 16 sites in IL6 and five out of twelve sites in the CXCL8 gene had significantly higher methylation in meditators. Although no significant difference in the overall methylation level in the promoter regions of TNF and IFNG genes was detected, two out of 12 sites and one out of 27 sites in the TNF and IFNG genes, respectively, showed significantly higher methylation in meditators. These findings suggest that long-term meditation practice may contribute to reduced inflammation by downregulating the expression of specific inflammatory pathway genes and increasing their promoter methylation.