cytochrome-c-t and Stress-Disorders--Post-Traumatic

Post-traumatic stress disorder (PTSD) is an anxiety disorder that develops after exposure to a life-threatening traumatic experience. Meta-analyses of the brainstem showed that midsagittal area of the pons was significantly reduced in patients with PTSD, suggesting a potential apoptosis in dorsal raphe nucleus after single-prolonged stress (SPS). The aim of this study is to investigate whether SPS induces apoptosis in dorsal raphe nucleus in PTSD rats, which may be a possible mechanism of reduced volume of pons and density of gray matter.. In this study, rats were randomly divided into 1d, 7d and 14d groups after SPS along with the control group. The apoptosis rate was determined using annexin V-FITC/PI double-labeled flow cytometry (FCM). Levels of Cytochrome c (Cyt-C) was examined by Western blotting. Expression of Cyt-C on mitochondria in the dorsal raphe nucleus neuron was determined by enzymohistochemistry under transmission electron microscopy (TEM). The change of thiamine monophosphatase (TMP) levels was assessed by enzymohistochemistry under light microscope and TEM. Morphological changes of the ultrastructure of the dorsal raphe nucleus neuron were determined by TEM.. Apoptotic morphological alterations were observed in dorsal raphe nucleus neuron for all SPS-stimulate groups of rats. The apoptosis rates were significantly increased in dorsal raphe nucleus neuron of SPS rats, along with increased release of cytochrome c from the mitochondria into the cytoplasm, increased expression of Cyt-C and TMP levels in the cytoplasm, which reached to the peak of increase 7 days of SPS.. The results indicate that SPS induced Cyt-C released from mitochondria into cytosol and apoptosis in dorsal raphe nucleus neuron of rats. Increased TMP in cytoplasm facilitated the clearance of apoptotic cells. We propose that this presents one of the mechanisms that lead to reduced volume of pons and gray matter associated with PTSD.

Topics: Animals; Apoptosis; Blotting, Western; Cytochromes c; Disease Models, Animal; Flow Cytometry; Microscopy, Electron, Transmission; Mitochondria; Neurons; Phosphoric Monoester Hydrolases; Raphe Nuclei; Rats; Rats, Wistar; Restraint, Physical; Stress Disorders, Post-Traumatic; Time Factors

The purpose of this study was to provide a novel insight into the mechanism of how amygdala might participate in PTSD by investigating the changes of cytochrome c oxidase (COX), caspase-9, and caspase-3 in the amygdala of single-prolonged stress (SPS) rats. A total of 80 healthy, male Wistar rats were selected for this study. The models of post-traumatic stress disorder (PTSD) were created by SPS, which is an established animal model for PTSD. The change of COX was detected by light microscope and transmission electron microscopy (TEM). The expression of caspase-9 and caspase-3 in the basolateral amygdala was examined by immunofluorescence and reverse transcription-polymerase chain reaction (RT-PCR). SPS exposure resulted in a significant change of COX in the SPS model groups compared with the normal control group. Evaluation by enzymohistochemistry indicated translocation of COX from mitochondria to cytoplasm. The expression of both caspase-9 and caspase-3 significantly increased 1 day after SPS stimulation, then gradually increased and peaked at SPS 7d. This findings suggest changes of COX, caspase-9, and caspase-3 in the amygdala of SPS rats, which may play important roles in the pathogenesis of PTSD.

Topics: Amygdala; Animals; Apoptosis; Caspase 3; Caspase 9; Cytochromes c; Disease Models, Animal; Enzyme Activation; Male; Rats; Rats, Wistar; Signal Transduction; Stress Disorders, Post-Traumatic; Stress, Psychological; Time Factors

Post-traumatic stress disorder (PTSD) is a stress-related mental disorder caused by experience of a traumatic event, and presents with characteristic symptoms including intrusive memories, hyperarousal, and avoidance. Recently, structural neuroimaging studies showed that hippocampal volumes were relatively low in PTSD patients. However, the mechanisms that cause such atrophy are not well understood. The aim of this study was to reveal the possible mechanisms involved in apoptosis induced by single-prolonged stress (SPS) in hippocampus of PTSD rats. SPS is one of the animal models proposed for PTSD. Rats exposure to SPS showed enhanced inhibition of the hypothalamo-pituitary-adrenal (HPA) axis, which has been reliably reproduced in patients with PTSD. Wistar rats were killed at 1, 4, 7, 14 and 28 days after exposure to SPS. Expression of caspase-9, caspase-3, cytochrome c, Bcl-2 and Bax was detected by immunohistochemistry, immunofluorescence, Western blotting and electron microscopy. Apoptotic cells were assessed by TUNEL method. Our results showed apoptotic cells were significantly increased in hippocampus of SPS rats, accompanied by release of cytochrome c from the mitochondria into the cytosol, increase of caspase-9 and caspase-3 expression and decrease of the Bcl-2/Bax ratio. The results indicate that SPS-induced apoptosis in hippocampus of PTSD rats, and the mitochondrial pathway was involved in the process of SPS-induced apoptosis.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Blotting, Western; Caspase 3; Caspase 9; Cytochromes c; Disease Models, Animal; Fluorescent Antibody Technique; Hippocampus; Immunohistochemistry; In Situ Nick-End Labeling; Male; Microscopy, Electron, Transmission; Mitochondria; Rats; Rats, Wistar; Stress Disorders, Post-Traumatic; Stress, Psychological