Peripheral gene expression profiling of CCK-4-induced panic in healthy subjects

Progress in understanding the genetic basis of panic attacks may extend current knowledge on susceptibility to panic and pathogenesis of panic disorder. In the present study we applied the microarray Illumina platform for whole genome expression profiling in healthy subjects participating in the CCK-4-induced panic test. The study sample consisted of 31 male and female healthy volunteers, who were categorized according to predefined criteria as "panickers" or "non-panickers" to a CCK-4 challenge. The gene expression profiles were measured on peripheral blood cells at baseline and at 120 min post-CCK-4 injection using Illumina Human-6 v2 BeadChips. The fold change was used to demonstrate rate of changes in average gene expressions between studied groups. Statistical analyses were performed using the false discovery rate (FDR). Gene expression profiling 2 hr post-CCK-4 challenge showed changes in transcriptional levels of 226 genes. A total of 61 genes were differentially expressed between panickers and non-panickers with most of them related to immune, enzymatic or stress regulation systems. Other distinctive mRNA transcripts were from the genes known to be related to phenotypes associated with increased occurrence of panic attacks, such as asthma, diabetes, or myocardial ischemia. Our findings provide preliminary evidence for genetic substrates of panic attacks on the transcriptional level and indicate potential biological proximity between acute panicogenesis and several somatic conditions.