Epigenetic alterations of the promoter region of the POMC gene in adolescent depressive disorder patients with non-suicidal self-injury behaviors
Abstract Background The incidence of non-suicidal self-injury (NSSI) behavior among adolescents increases year by year. Patients with a history of both depression and NSSI behaviors tend to have greater risk of suicide. At present, the mechanism of adolescent depressive disorder patients with NSSI behaviors is not clear, epigenetic mechanism may be involved. Proopiomelanocortin (POMC) gene may be associated with depressive disorder. The purpose of this study was to investigate deoxyribonucleic acid (DNA) methylation of POMC gene promoter region of adolescent depressive disorder patients with NSSI behaviors. Methods Bisulfite Sequencing PCR (BSP) was used to test the methylation level of POMC promoter of 15 adolescent depressive disorder patients with NSSI behaviors and 15 healthy controls (HC). The online software Methylation Share Rate (MSR) Calcalate was used to draw the lollipop model of the methylation state. Self-made questionnaires were used to collect clinical data of the case group and control group. Hamilton depression scale-24 (HAMD-24), Hamilton anxiety scale (HAMA), Symptom Checklist-90 (SCL-90) were used to evaluate the characteristics and severity of depressive, anxiety and psychotic symptoms. Adolescent self-injury questionnaire was used to assess NSSI behaviors and its severity. Results BSP analysis found that the POMC methylation level of cytosine-guanine dinucleotide 1 (CpG1) site was higher in adolescent depressive disorder patients with NSSI behaviors than that of HC (P < 0.05). Overall significance in POMC methylation at CpG1 sites between adolescent depressive disorder patients with NSSI behaviors and HC was gender-independent, methylation level at CpG1 sites was higher in both male and female patients than that in HC. The CpG1 methylation had correlation with the family history (P < 0.05). We also found that POMC methylation level at CpG17 sites in female patients was significantly higher than that of the female HC (P < 0.05). Conclusions There was abnormal methylation in the POMC promoter region of adolescent depressive disorder patients with NSSI behaviors, the methylation of CpG1 sites may act as epigenetic markers for those adolescents.