The association between methylation in specific cpg sites of slc6a4 gene promoter region and prognosis of acs patients with different level of burnout
Authors: Zhang H , Zhang M 
Published: October 2021

Abstract

Background
Given that psychosocial disorders like depression and burnout are top causes of disease burden, meanwhile have negative effect on the prognosis of acute coronary syndrome (ACS), many studies mounted on their pathogenesis. Recently, epigenetic modifications of stress-related genes like serotonin transporter gene (SLC6A4) have been found to be involved in these disease courses, but the study to investigate the influence of methylation of SLC6A4 gene on the association of these disorders and prognosis of ACS is not found.

Objectives
To investigate the association of methylation of SLC6A4 gene and prognosis of patients with ACS who were in different level of burnout.

Methods
Patients with first onset of ACS were enrolled, and their blood sample, demographic and clinical data were collected. Then they were evaluated baseline level of burnout, anxiety, depression, quality of life and heart rate variability (HRV) before discharge, by Copenhagen Burnout Inventory (CBI), Hospital Anxiety and Depression Scale (HADS), 8-item Short Form Generic Health-Related Quality-of-life Questionnaire (SF-8), Seattle Angina Questionnaire (SAQ) and ambulatory electrocardiogram (24h-AECG) respectively. At one-month and six-month's follow-up, their physical performance was evaluated by Short Physical Performance Battery (SPPB) and same indices above were assessed repeatedly. Genomic DNA was extracted from whole blood, and methylation level in 11 CpG sites of SLC6A4 gene promotor region were tested by bisulfite sequencing PCR (BSP) technique. Last, the associations among burnout, anxiety, depression, and their interactions with methylation were analyzed by IBM SPSS Statistics 24.0, so as the association of methylation and the prognosis of ACS.

Results
74 patients were enrolled. Chi-square test implied that methylation of CpG7 was more obvious in non-anxiety group compared to anxiety group. And log linear model was used to explore the association among burnout, anxiety, depression, and their interactions with methylation, only the interaction of non-methylation of CpG7 and anxiety was positively correlated to the distribution of frequency. Next, five CpG sites (CpG6–10) were included in generalized estimating equations (GEEs) to analyze the association of methylation and prognosis indices of ACS patients. Results showed that methylation of CpG7 was positively correlated to standard diviation of NN intervals (SDNN), square root of the mean squared differences of successive NN intervals (RMSSD), high frequency (HF), low frequency (LF), very low frequency (VLF), total power (TP), and no significant relations were found among the score of SPPB, SF-8, SAQ and methylation.

Conclusions
Methylation in CpG7 of SLC6A4 gene promotor region may foretell a good prognosis of ACS patients by being correlated to less anxiety. Epigenetic modifications could be promising biomarkers to help identifying people that need special rehabilitation strategy.

Funding Acknowledgement
Type of funding sources: Foundation. Main funding source(s): Nature Science Foundation of Yunnan Province; Yunnan Health Training Project of High Level Talents