The Relation Between The Symptoms Characteristics Of Post-traumatic Stress Disorder Like Model,Telomere And Insulin-like Growth Factors

Part ⅠTelomere Length and Telomere Repeating Factors:Cellular Markers for PTSDObjectiveThe aim of the present study was to explore the telomere length of peripheral blood leukocytes from a rat model of post-traumatic stress disorder (PTSD), as well as the expression level of telomere-binding protein in the hippocampal CA1 region.MethodsThe PTSD model was established with 42 adult male Wistar rats. The relative telomere length of the leukocytes was measured by real-time fluorescence quantitative polymerase chain reaction, and the expression levels of telomere repeating factor 1 (TRF1) and telomere repeating factor 2 (TRF2) in the hippocampal CA1 region of the PTSD rat model were determined by immunofluorescence (IF) technology.ResultsThe shortening speed of telomere length significantly accelerated in rats after Single Prolonged Stress (SPS) stimulation (P< 0.05). The expression levels of TRF1 and TRF2 increased with the progress of PTSD, and the expression peak was shown in day 14, which was significantly different from the control group (P< 0.05).ConclusionThe shortening speed of the telomere length of peripheral blood leukocytes accelerated in PTSD rats, and the expression levels of TRF1 and TRF2 increased in hippocampus, both of which were closely associated with the pathological progress of PTSD and unfavorable prognosis.Part IIThe Significates of IGF-1 and IGF-1R in Reducing PTSD Cognitive Function SymptomsObjectiveTo study the expressions of insulin-like growth factor-1 (IGF-1) and IGF-1 receptor in the hippocampal CA1 region of post-traumatic stress disorder (PTSD) rats.MethodsForty healthy adult male Wistar rats were adopted. The internationally established single prolonged stress (SPS) method was used to set up the PTSD rat model, and the immunohistochemical (IHC) method was applied to detect the expressions of IGF-1 and its receptor in the hippocampal CA1 region of PTSD rats.ResultsAfter SPS stimulus, the expression of IGF-1 protein in the rat hippocampal CA1 region increased with the development of PTSD, and reached the maximum on the 14th day, which is statistically different from that of the control group (P<0.05); While the expression of IGF-1 receptor protein showed no significant difference on the 1st day and 7th day before and after stress (P>0.05), but slightly decreased on the 14th day and 28th day than before (P<0.05).ConclusionAfter stress, the expression of IGF-1 receptor didn’t grow in pace with that of IGF-1 accordingly, but slightly lowered instead. This indicates that IGF-1 receptor may affect the positive role of IGF-1 to some degree, and meanwhile involve the pathophysiological process of cognitive changes of PTSD.