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Retinal ischemia/reperfusion (I/R) injury can occur as a result of a number of ocular diseases or ischemic events in the brain, leading to possible vision loss if not treated properly. The overproduction of reactive oxygen species is important in the process of I/R injury. Edaravone, a free radical scavenger, has been demonstrated to have a neuroprotective effect in cerebral ischemia; however, its effect against retinal I/R injury remains to be fully elucidated. Therefore, the present study investigated the effects of edaravone on the oxidative parameters, retinal inflammation and apoptosis induced by I/R injury, and treated photoreceptor‑derived 661W cells with hydrogen peroxide (H2O2) and edaravone to examine the underlying mechanism. For the in vivo study, oxidative parameters (malondialdehyde, DNA fragmentation, total antioxidant status, superoxide dismutase and glutathione) in the retina, retinal thickness, and apoptotic index in the ganglionic cell layer and inner nuclear layer were measured. For the in vitro study, the effects of edaravone or nuclear factor erythroid‑2‑related factor 2 (Nrf2) small interfering RNA or phosphatidylinositol 3‑kinase (PI3K)/Akt inhibitors on cell viability, membrane integrity, levels of phosphorylated‑Akt, Akt and nuclear Nrf2 of H2O2‑treated 661W cells were examined. The results demonstrated that edaravone inhibited the oxidative injury in the retina induced by the retinal I/R procedure and increased retinal inflammation, and apoptosis. The results of the in vitro experiments demonstrated that edaravone effectively protected the viability and the membrane integrity of the H2O2‑treated 661W cells via the phosphatidylinositol 3‑kinase (PI3K)/Akt/Nrf2pathway. These results indicated the potential protective effect of edaravone against retinal I/R injury and provided a novel explanation for the protective effects of edaravone.

The proliferation of retinal pigment epithelium (RPE) cells following epithelial-mesenchymal transition (EMT) is critical in proliferative vitreoretinopathy (PVR), which results in retinal detachment and the loss of vision. The current study was conducted to examine the importance of transforming growth factor β-1 (TGF-β1)-activated kinase 1 (TAK1) inhibitor (LYTAK1) in regulating EMT and the proliferation of RPE cells. RPE cells were pre-treated with increasing concentrations of LYTAK1 prior to treatment with TGF-β1 for 24 h. The effect of LYTAK1 on RPE cell proliferation was examined using a Cell Counting kit-8 assay. The expression levels of TAK1, smooth muscle actin, fibronectin, p-Smad2, p-Smad3, nuclear factor (NF)-κB p65 and IκB kinase α were detected by western blotting. LYTAK1 suppressed the proliferation and migration of RPE cells. Additionally, LYTAK1 significantly prevented TGF-β1-induced EMT by decreasing the levels of fibronectin and α-smooth muscle actin. It was demonstrated that the effects of LYTAK1 were via the Smad signaling pathway. The present study also determined, that the underlying mechanism of the effects of LYTAK1 on EMT in RPE cells involves downregulation of the NF-κB signaling pathway. In conclusion, TAK1 transcription factor was shown to be important in TGF-β1-induced EMT in human RPE cells. Thus, the results of this study aid in elucidating the pathogenesis of human PVR. In addition, this study suggests that specific inhibition by LYTAK1 may provide a novel approach for the treatment and prevention of PVR.

Hypoxia is a type of cellular stress that may result in apoptosis and autophagy. The molecular mechanisms underlying the association between autophagy and apoptosis remain unclear, particularly in hypoxic conditions. Transmission electron microscope, AO-PI staining, flow cytometry and western blot were used to examine the crosstalk between autophagy and apoptosis in hypoxic conditions. Rat alveolar type II epithelial RLE-6TN cells were cultured in a long-term hypoxic environment established by cobalt (II) chloride. It was demonstrated that autophagy and apoptosis occurred in RLE-6TN cells under hypoxic conditions. Treatment of RLE-6TN cells with the autophagy inhibitor 3-methyladenine increased the generation of reactive oxygen species, mitochondrial damage and hypoxia-induced apoptosis. The expression of caspases, particularly caspase-9, increased and may have participated in these processes. The data indicated that the inhibition of autophagy enhanced apoptosis through the mitochondria-mediated intrinsic pathway. These findings provide important insight into the molecular mechanism of autophagy and apoptosis crosstalk. This may provide new insights into pulmonary disease surveillance, diagnosis and treatment.

The aim of the present study, was to investigate the involvement of the endoplasmic reticulum (ER) in post-traumatic stress disorder (PTSD) by detecting changes of ER chaperone protein 78 and ER-resident caspase 12 in the basolateral amygdala after exposure to single prolonged stress (SPS). The established rat model of PTSD was generated by exposure of the animals to SPS. The expression of glucose-regulated protein 78 (GRP78) was examined by immunofluorescence, western blot and reverse transcription-polymerase chain reaction (RT-PCR), and the expression of caspase 12 was examined by western blot and RT-PCR. The morphological changes of the ER were detected by transmission electron microscopy. The results showed that GRP78 expression significantly increased when compared to that in the control group 1 day after SPS exposure (P

The amygdalae are an important component of the human limbic system and exhibit a key role in emotional and behavioral reactions. Previous studies have demonstrated abnormal function and morphology in the amygdalae of post‑traumatic stress disorder (PTSD)‑like animal models, however the underlying molecular mechanisms remain elusive. The authors have previously demonstrated that PTSD induced increased apoptosis in the amygdala of PTSD‑like animals. Cyclin D1 and cyclin‑dependent kinase 4 (CDK4) are two important regulators of the cell cycle. The study explored the expression of cyclin D1 and CDK4 in the amygdala in PTSD. The single‑prolonged stress (SPS) rat model was used as a PTSD‑like model. Ultrastructural alterations of cells in the amygdala were observed using transmission electron microscopy (TEM). 4',6‑Diamidino‑2‑phenylindole (DAPI) fluorescence was employed to detect nuclear pycnosis. Cyclin D1 and CDK4 expression in the amygdala cells was examined using immunofluorescence, Western blotting and reverse transcription‑quantitative polymerase chain reaction. TEM revealed morphological alterations to the amygdala cells of the SPS rats. DAPI‑stained nuclear brightness levels differed between the control and SPS groups. Expression of cyclin D1 and CDK4 in the amygdala increased gradually 1 day and 4 days following SPS stimulation, and peaked 7 days following SPS stimulation at the protein and mRNA levels, in comparison with the control rats. These findings suggest that SPS resulted in increased cyclin D1 and CDK4 expression, which may accelerate cell apoptosis. This may be associated with SPS‑induced abnormal function and structure of the amygdala.

Post‑traumatic stress disorder (PTSD) is a stress‑accociated mental disorder that occurs as a result of exposure to a traumatic event, with characteristic symptoms, including intrusive memories, hyperarousal and avoidance. The medial prefrontal cortex (mPFC) is known to be significantly involved in emotional adjustment, particularly introspection, inhibition of the amygdala and emotional memory. Previous structural neuroimaging studies have revealed that the mPFC of PTSD patients was significantly smaller when compared with that of controls and their emotional adjustment function was weakened. However, the mechanisms that cause such atrophy remain to be elucidated. The aim of the present study was to elucidate the possible mechanisms involved in apoptosis induced by single‑prolonged stress (SPS) in the mPFC of PTSD rats. SPS is an animal model reflective of PTSD. Of the proposed animal models of PTSD, SPS is one that has been shown to be reliably reproducible in patients with PTSD. Wistar rats were sacrificed at 1, 4, 7 and 14 days after exposure to SPS. Apoptotic cells were assessed using electron microscopy and the TUNEL method. Expression of integrin αv, vinculin and connexin43 were detected using immunohistochemistry, western blotting and reverse transcription polymerase chain reaction. The present results demonstrated that apoptotic cells significantly increased in the mPFC of SPS rats, accompanied with changes in expression of integrin αv, vinculin and connexin43. The present results indicated that SPS‑induced apoptosis in the mPFC of PTSD rats and the mitochondrial pathway were involved in the process of SPS‑induced apoptosis.

Serious complications as a result of type 2 diabetes mellitus (T2DM) are becoming a major health concern. In the present study, it was hypothesized that telomerase activity is upregulated in vascular smooth muscle cells (VSMCs) during proliferation in T2DM and that the application of telomerase inhibitors impedes the proliferation of VSMCs in vitro. Male Wistar rats were randomly allocated into the normal control (NC) or diabetic (DM) group. Diabetes was induced by high‑fat feeding and a low dose of streptozotocin (STZ; 30 mg/kg). Primary VSMC cultures were exposed to normal (5.5 mM) or high (25 mM) glucose and insulin (100 nM) in the presence and absence of various concentrations of antisense oligoribonucleotides (ASODNs) for varying lengths of time. Telomerase activity and the proliferation of VSMCs were measured. Results showed that there was a significant increase in the levels of fasting glucose, insulin, triglycerides (TG) and free fatty acids (FFAs) in the diabetic group. Telomerase activity and the proliferation of VSMCs were significantly higher in the diabetic group in vivo and in the high glucose and insulin (HGI)-treated group in vitro (P

The tetraspanin CD9 has previously been shown to be involved in various cellular activities, including proliferation and migration. In addition, CD9 has been shown to be associated with epidermal growth factor receptor (EGFR). A common characteristic of glioblastoma multiforme histology is EGFR amplification, which affects signal transduction processes. The anti-proliferative effects of CD9 have been linked to EGFR signaling pathways, including phosphorylation of phosphoinositide-3-kinase (PI3K)/Akt and activation of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated protein kinase (Erk). The present study demonstrated that CD9 decreased the phosphorylation of EGFR at specific sites. In addition, CD9 attenuated EGFR signaling of PI3K/Akt and MAPK/Erk, which was associated with cell growth and proliferation. Conversely, small hairpin RNA-mediated knockdown of CD9 expression enhanced the activation of EGFR signal transduction pathways, including PI3K/Akt and MAPK/Erk. These results suggested that the mechanism underlying CD9-induced suppression of cell proliferation may involve the inhibition of phosphorylation of EGFR and the activity of PI3K/Akt and MAPK/Erk signaling pathways.

It is not clear whether or not the mineralocorticoid receptor (MR) is involved in post-traumatic stress disorder (PTSD). The purpose of this study was to provide novel insights into the mechanism(s) through which the medial prefrontal cortex (mPFC) plays a role in PTSD by investigating MR expression in the mPFC of rats exposed to single prolonged stress (SPS), which is an established animal model for PTSD. A total of 90 healthy, male Wistar rats were selected for this study and randomly divided into normal control and SPS groups of 1, 7, 14 and 28 days. This study investigated the changes in MR expression in the mPFC of rats after SPS, which revealed pathogenetic mechanisms. The expression of MR in the mPFC was examined by immunofluorescence, western blotting and reverse transcription-polymerase chain reaction (RT-PCR). SPS exposure resulted in a significant change in MR expression in the SPS model groups compared with the normal control group. The MR protein was found to be localized in the cytoplasm and its expression levels were significantly increased in SPS rats, peaking at SPS 7 days, followed by a gradual decrease; however, a positive expression revealed a restoratory increase in the SPS-28 day group. The results suggest that MR plays an important role in the pathology of PTSD.

Post-traumatic stress disorder (PTSD) is characterized mainly by symptoms of re-experiencing, avoidance and hyperarousal as a consequence of catastrophic and traumatic events that are distinguished from ordinary stressful life events. Single-prolonged stress (SPS) is an established animal model for post-traumatic stress disorder (PTSD). The dorsal raphe nucleus (DR)-serotonin (5-HT) system is markedly affected by swim stress and has been implicated in affective disorders. The 5-HT1A receptor (5-HT1AR) is critically involved in regulating mood and anxiety levels. In this study, we investigated changes in the expression of 5-HT1AR in the DR of rats after SPS that may reveal part of the pathogenesis of PTSD. 5-HT1AR expression in the DR was examined using immunohistochemistry, Western blotting and reverse transcription polymerase chain reaction. The expression of 5-HT1AR in the DR after SPS exposure was increased when compared to that in the control group (P

The extracellular signal-regulated kinase (ERK) signaling transduction pathway has been implicated in multiple physiological processes. It is not clear whether the ERK1/2 pathway participates in post-traumatic stress disorder (PTSD). The aim of this study was to provide novel insights into the mechanisms of how the amygdala participates in PTSD by investigating changes in the ERK1/2 pathway induced by single prolonged stress (SPS). The level of phosphorylated ERK1/2 (pERK1/2) protein was defined in a single-prolonged stress (SPS) animal model of post-traumatic stress disorder. A total of 100 male Wistar rats were randomly divided into a normal control group and SPS groups of 0, 30, 60 and 120 min. pERK1/2 distribution in the amygdala neurons was observed using immune electron microscopy. The expression of pERK1/2 was examined by immunohistochemistry and Western blotting. The pERK protein was located in some cell organelles, such as the mitochondria and neuraxon. Quantitatively, the expression of pERK protein level was significantly increased in the SPS rats. The results suggest that the ERK signal transduction pathway may play a crucial role in the pathology of PTSD.

Evidence suggests that the volume of the amygdala is significantly reduced in patients with post-traumatic stress disorder (PTSD), and that this may be related to neuronal apoptosis. However, the precise molecular mechanism of this decrease in amygdala volume during PTSD remains unclear. In this study, we investigated the relationship between the activity of the 5-HT1A receptor and amygdala neuronal apoptosis. Rats were exposed to a single-prolonged stress (SPS) procedure to create a PTSD rat model, with or without prior treatment with WAY100635, a 5-HT1A receptor antagonist. The expression of Bax, a pro-apoptotic protein, and Bcl-2, an anti-apoptotic protein, was examined by Western Blotting. TUNEL staining and flow cytometry (FCM) were employed for the detection of apoptotic cells in the amygdala. Our results indicate that SPS induces amygdala neuronal apoptosis, which was partially inhibited by WAY100635, and suggest that this apoptosis may be related to the activity of the 5-HT1A receptor.