Association of Bax and Bcl-2 Functional Polymorphisms and Protein Levels with Posttraumatic Stress Disorder

Background: Posttraumatic stress disorder (PTSD) is an anxiety disease influenced by both environmental and genetic factors, which affects a patient’s quality of life and social stability. Recent studies have shown that the pathogenesis of PTSD is associated with apoptosis;however, the molecular mechanisms that cause such damage are not well-understood. Also it is unclear whether these pathologic alterations are genetically determined or caused by other factors. The aim of this study was to investigate the genetic association of functional polymorphisms in genes coding for apoptosis-related Bcl-2 and Bax proteins with PTSD as well as proteins levels in the blood of affected subjects. Methods: The study groups consisted of 200 combat veterans with PTSD and an equal number of healthy subjects with no family- or past-history of any psychiatric disorders. Bax and Bcl-2 proteins levels in blood were measured by ELISA. DNA samples were genotyped for SNPs using PCR-SSP. Results: According to our results, PTSD patients are characterized by increased levels of apoptotic proteins and the imbalance in the Bax/Bcl-2 ratio compared to healthy subjects. Our results also demonstrate that rs956572*A minor allele of the BCL2 gene was overrepresented in patients with PTSD compared to healthy subjects. Conclusions: The results implicate Bcl-2 and Bax in pathogenesis of PTSD on genetic and protein levels, though further studies on enlarged cohort and in different populations are required.

Genetic Polymorphisms of Nervous System Development and the Risk of Posttraumatic Stress Disorder

Background: Posttraumatic stress disorder (PTSD) is a complex severe polygenic psychiatric disease, influenced by environmental and genetic factors. PTSD development and progression is characterized by cognitive impairment, which may result in altered processes of nervous system development and synaptic plasticity, where a number of growth factors and their receptors were shown to play important role. Since neurotrophins play an essential role in the development of central nervous system, it is widely implicated in psychiatric disorders. The aim of this study is to investigate the potential association functional polymorphisms of genes encoding netrin G1 (NTNG1), brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF) and its receptor (NGFR) with PTSD. Methods: Study groups consisted of 200 combat veterans with PTSD and an equal number of controls with no family or past history of any psychiatric disorders. The DNA samples were genotyped for NTNG1 rs62811;BDNF rs6265;NGF rs6330, rs4839435;NGFR rs11466155, rs734194 SNPs using polymerase chain reaction with sequence specific primers. Results: According to the results, NGF rs6330 was overrepresented in patients with PTSD compared to controls. Furthermore, negative association for BDNF rs6265, NGF rs4839435 and NGFR rs734194 was observed in PTSD patients. Conclusions: In summary, BDNF rs6265, NGF rs6330, rs4839435 and NGFR rs734194 are implicated in PTSD in Armenian population. However, further research is required to provide the definitive evidence of selected polymorphism association with gene expression.