Effects of earthquake and related environmental factors on relationship of posttraumatic stress disorder with LDLR rs5925

Suicidal ideation in adolescents with adiponectin receptor 2 rs12342 polymorphism affected by Wenchuan earthquake

PURPOSE

The present study was to investigate prevalence of suicidal ideation and its associations with biological and environmental factors in adolescents with different genotypes of rs12342 at adiponectin receptor 2 gene (ADIPOR2).

METHODS

Suicidal ideation, biological and environmental factors were evaluated by questionnaires in 669 high school students after Wenchuan earthquake in China. ADIPOR2 rs12342 was genotyped by polymerase chain reaction-restriction fragment length polymorphism and verified by DNA sequencing.

RESULTS

Female adolescents had higher prevalence of suicidal ideation than male students in AG heterozygote and GG homozygote, but not AA homozygote. Prevalence of suicidal ideation was different in male, but not female, subjects with different genotypes. Genotype and allele frequencies were significantly different between male students with and without suicidal ideation, but not the female counterparts. Family history of mental disorders, extent of damage to property, carbohydrate intake and protein intake were associated with suicidal ideation in female subjects, while ADIPOR2 rs12342, father's educational level and previous trauma experience were associated with suicidal ideation in male subjects.

CONCLUSION

ADIPOR2 rs12342 is associated with and has potential to interact with environmental factors on suicidal ideation in a gender-dependent manner in youth. These findings pave a novel way and perspective for precision inferences of suicidal ideation in subjects with different genetic backgrounds. ADIPOR2 rs12342 needs to be considered when intervening suicidal ideation, especially in adolescents.

Post-Traumatic Stress Disorder Is Associated with Elevated Plasma Cholesterol in Female TT Homozygotes of LDLR rs5925

To explore the mechanism of inconsistent relationships between plasma lipid profiles and post-traumatic stress disorder (PTSD) reported before, we hypothesized that interplays might exist between PTSD and a variation of rs5925 at low-density lipoprotein receptor (LDLR) gene on plasma lipid profiles. To test our hypothesis, we analyzed the plasma lipid profiles of 709 high school pupils with various genotypes of LDLR rs5925 and with or without PTSD. The results demonstrated that PTSD prevalence in the C allele carriers was higher than that in the TT homozygotes regardless of gender. The C allele carriers had higher levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), ratios of TC to high-density lipoprotein cholesterol (TC/HDL-C) and LDL-C/HDL-C than the TT homozygotes in the male controls, and only higher TC in the female controls, but no differences in the male or female PTSD subjects. PTSD increased TC in the female TT homozygotes but not in the female C allele carriers. PTSD increased TC/HDL-C in the male TT homozygotes but not in the C allele carriers. These results suggest interactions between PTSD and LDLR rs5925 on plasma lipid profiles, which may be among the explanations for previously reported inconsistent relationships between LDLR rs5925 or PTSD and plasma lipid profiles, and facilitate the development of precision medicine interferences in hypercholesterolemia in individuals with different genetic backgrounds and psychiatric status. Psychiatric care or drug supplement may particularly be needed by female hypercholesterolemic subjects with the TT genotype of LDLR rs5925 in Chinese adolescents.

Apolipoprotein E Isoform-specific changes related to stress and trauma exposure

Post-Traumatic Stress Disorder (PTSD) is a highly prevalent mental health disorder. Due to the high level of variability in susceptibility and severity, PTSD therapies are still insufficient. In addition to environmental exposures, genetic risks play a prominent role and one such factor is apolipoprotein E. The protein (apoE) is functionally involved in cholesterol transport and metabolism and exists as 3 major isoforms in humans: E2, E3, and E4. To model the role of apolipoprotein E isoform in stress-related changes in behavior and cognition, female and male mice (3-5 months of age) expressing E2, E3, or E4 were used. Mice were either placed into control groups or exposed to chronic variable stress (CVS), which has been shown to induce PTSD-like behavioral and neuroendocrine changes. E2 mice showed a unique response to CVS compared to E3 and E4 mice that included impaired spatial learning and memory, increased adrenal gland weight, and no increase in glucocorticoid receptor protein levels (normalized to apoE levels). In addition, the cholesterol metabolite 7-ketocholesterol was elevated in the cortex after CVS in E3 and E4, but not E2 female mice. E2 confers unique changes in behavioral, cognitive, and biomarker profiles after stress exposure and identify 7-ketocholesterol as a possible novel biomarker of the traumatic stress response. We further explored the relationship between E2 and PTSD in an understudied population by genotyping 102 patients of Cambodian and Vietnamese ethnicity. E2 carriers demonstrated a higher odds ratio of having a PTSD diagnosis compared to E3/E3 carriers, supporting that the E2 genotype is associated with PTSD diagnosis after trauma exposure in this population.