Oxidative stress mediates hippocampal neuronal apoptosis through ROS/JNK/P53 pathway in rats with PTSD triggered by high-voltage electrical burn

Background: The pathogenesis of post-traumatic stress disorder (PTSD) triggered by high-voltage electrical burn (HVEB) remains unclear and the oxidative stress plays a role in this process. The purpose of this study is to investigate the underlying mechanism of oxidative stress mediates hippocampal neuronal apoptosis in rats with PTSD triggered by HVEB. Materials and methods: The PTSD rat model was developed by stimulating with high voltage electricity and screened using behavioral performance including Morris water maze (MWM), elevated plus-maze (EPM) and open-field test (OFT). The reactive oxygen species (ROS) generation was measured by DHE fluorescence staining or flow cytometry. Western blotting assay was used to detect the proteins of p-JNK, JNK, P53, PUMA, Bcl-2 and Bax in hippocampal tissue or HT22 cells treated with electrical stimulation. Results: The serum MDA and 8-OHdG levels were increased (P < 0.001), while the activities of SOD and CAT were decreased (P < 0.001) significantly in patients with HVEB. Behavioral test results showed that high-voltage electric stimulation induced the PTSD-like symptoms and the ROS-JNK-P53 pathway was involved in the neuronal apoptosis in rats with PTSD induced by HVEB. In vitro experiments further confirmed the electrical stimulation induced neuronal apoptosis through ROS/JNK/P53 signaling pathway and the antioxidant NAC could rescued the ROS generation, activation of JNK/P53 proteins and improved the cell apoptosis rate in HT22 cells. Finally, the JNK inhibitor SP600125 could significantly inhibited the percentage of HT22 cell apoptosis induced by electrical stimulation (P < 0.001). Conclusions: These results indicated that oxidative stress mediates hippocampal neuronal apoptosis through ROS/JNK/P53 pathway in rats with PTSD triggered by HVEB

Neuroprotective Effects of Pre-Treament with l-Carnitine and Acetyl-l-Carnitine on Ischemic Injury In Vivo and In Vitro

The therapeutic effect of stroke is hampered by the lack of neuroprotective drugs against ischemic insults beyond the acute phase. Carnitine plays important roles in mitochondrial metabolism and in modulating the ratio of coenzyme A (CoA)/acyl-CoA. Here, we investigate the neuroprotective effects of l-carnitine (LC) and Acetyl-l-carnitine (ALC) pre-treatment on ischemic insults under the same experimental conditions. We used a transient middle cerebral artery occlusion (MCAO) model to evaluate the protective roles of LC and ALC in acute focal cerebral ischemia in vivo and to understand the possible mechanisms using model of PC12 cell cultures in vitro. Results showed that ALC, but not LC, decreased infarction size in SD rats after MCAO in vivo. However, both LC and ALC pretreatment reduced oxygen-glucose deprivation (OGD)-induced cell injury and decreased OGD-induced cell apoptosis and death in vitro; at the same time, both of them increased the activities of super oxide dismutase (SOD) and ATPase, and decreased the concentration of malondialdehyde (MDA) in vitro. Thus, our findings suggested that LC and ALC pre-treatment are highly effective in the prevention of neuronal cell against ischemic injury in vitro, however, only ALC has the protective effect on neuronal cell injury after ischemia in vivo

Oxidative Stress Mediated-Alterations of the MicroRNA Expression Profile in Mouse Hippocampal Neurons

Oxidative stress plays a critical role in the etiology and pathogenesis of neurodegenerative disorders, and the molecular mechanisms that control the neuron response to ROS have been extensively studied. However, the oxidative stress-effect on miRNA expression in hippocampal neurons has not been investigated, and little is known on the effect of ROS-modulated miRNAs on cell function. In this study, H2O2 was used to stimulate the mouse primary hippocampal neurons to develop an oxidative stress cell model. The alterations of miRNAs expression were detected by microarray analysis and five miRNAs were validated by real-time RT-PCR. The bioinformatic analysis of deregulated miRNAs was performed to determine their potential roles in the pathogenesis of neurological disorders. We found that H2O2 mediated a total of 101 deregulated miRNAs, which mainly took part in the regulation of the MAPK pathway. Among them, miR-135b and miR-708 were up-regulated significantly and their targets were predicted to be involved in DNA recombination, protein ubiquitination, protein autophosphorylation and development of neurons. These results demonstrated that oxidative stress alters the miRNA expression profile of hippocampal neurons, and the deregulated miRNAs might play a potential role in the pathogenesis of neurodegenerative diseases, such as Alzheimer’s disease (AD)

Carboxymethylcellulose binds to human corneal epithelial cells and is a modulator of corneal epithelial wound healing

PURPOSE. In this study, the ability of carboxymethylcellulose (CMC), used in artificial tear formulations, to interact with corneal-epithelial-cells (HCECs) and facilitate corneal epithelial wound healing was investigated. METHODS. HCECS were incubated with fluorescein-labeled CMC (F-CMC). CMC-epithelial binding was measured by spectrophotometry. The effect on F-CMC binding by hyaluronic acid (HA) or glucose was measured after preincubation in HA, mAb to CD44, or glucose, or mAb to GluT-1. F-CMC binding to fibronectin or collagen was measured by incubating proteins with F-CMC. The wound widths were measured 18 hours after confluent HCECs were scratch wounded. The ability of CMC to induce cell chemotaxis, proliferation, or migration was measured by quantitative assay. The efficacy of CMC in promoting epithelial wound healing was also tested in a rabbit epithelial scrape-wound model. RESULTS. CMC remained bound to the HCECs for 2 hours. Preincubation of HCECs with glucose or mAb to GluT-1, but not with HA or mAb to CD44, reduced the binding of CMC to HCECs from 43.7% to 67.2% or 10.9% to 25.3%, respectively. CMC bound significantly to fibronectin (3.1-fold) or collagen (9.3-fold) compared with the control (BSA), and such binding enhanced cell adhesion. CMC stimulated re-epithelialization of HCECs scratched in vitro and in vivo rabbit cornea epithelial scrape wounds. CMC stimulated cell migration but not proliferation. CONCLUSIONS. CMC probably binds to HCECs through interaction of its glucopyranose subunits with glucose transporters. CMC binding to the matrix proteins stimulated HCEC attachment, migration, and re-epithelialization of corneal wounds.9 page(s

Using Regional Homogeneity to Reveal Altered Spontaneous Activity in Patients with Mild Cognitive Impairment

Most patients with mild cognitive impairment (MCI) are thought to be in an early stage of Alzheimer’s disease (AD). Resting-state functional magnetic resonance imaging reflects spontaneous brain activity and/or the endogenous/background neurophysiological process of the human brain. Regional homogeneity (ReHo) rapidly maps regional brain activity across the whole brain. In the present study, we used the ReHo index to explore whole brain spontaneous activity pattern in MCI. Our results showed that MCI subjects displayed an increased ReHo index in the paracentral lobe, precuneus, and postcentral and a decreased ReHo index in the medial temporal gyrus and hippocampus. Impairments in the medial temporal gyrus and hippocampus may serve as important markers distinguishing MCI from healthy aging. Moreover, the increased ReHo index observed in the postcentral and paracentral lobes might indicate compensation for the cognitive function losses in individuals with MCI

Oxidative stress mediated-alterations of the MicroRNA expression profile in mouse hippocampal neurons

Abstract: Oxidative stress plays a critical role in the etiology and pathogenesis of neurodegenerative disorders, and the molecular mechanisms that control the neuron response to ROS have been extensively studied. However, the oxidative stress-effect on miRNA expression in hippocampal neurons has not been investigated, and little is known on the effect of ROS-modulated miRNAs on cell function. In this study, H2O2 was used to stimulate the mouse primary hippocampal neurons to develop an oxidative stress cell model. The alterations of miRNAs expression were detected by microarray analysis and five miRNAs were validated by real-time RT-PCR. The bioinformatic analysis of deregulated miRNAs was performed to determine their potential roles in the pathogenesis of neurological disorders. We found that H2O2 mediated a total of 101 deregulated miRNAs, which mainly took part in the regulation of the MAPK pathway. Among them, Int. J. Mol. Sci. 2012, 13 16946 miR-135b and miR-708 were up-regulated significantly and their targets were predicted t

Carboxymethyl cellulose stimulates rabbit corneal epithelial wound healing

Purpose: Previously, we reported carboxymethyl cellulose (CMC) binding to human corneal epithelial cells and promoting corneal epithelial wound closure in vitro. Using an animal model, the efficacy of CMC in promoting corneal wound healing was examined. Materials and Methods: Following corneal epithelial wounding of NZ white rabbits, CMC (0.2% or 1.0%) or control vehicle (PBS) was administered topically (4 times daily for 3 days) to wounded and unwounded eyes with or without contact lens wear. Wound healing in response to the treatments was measured as percentage reduction of fluorescein-stained wound area 0 to 72 hr post-wounding. Corneas were examined histologically and expression of zonula occludens-1 (ZO-1) tight-junction was detected by immunohistochemistry. Results: Percentage wound reduction in CMC-treated groups was significantly greater than controls (p < 0.05) at 24 and 32 hr. Complete wound closure was observed by 48 hr in 100% of CMC-treated eyes compared to 45% of vehicle-treated eyes. CMC also promoted wound closure dose-dependently. Epithelial cells formed an intact layer following CMC-treatment whereas vehicle-treated cells were less ordered. Strong ZO-1 expression in corneal epithelia of CMC-treated eyes was observed at 72 hr. Contact lens wear appeared to delay wound closure compared to without lens wear during CMC-treatment (p = 0.001). Conclusions: CMC promoted dose-dependent corneal epithelial wound healing. CMC stimulated ZO-1 expression, indicating accelerated corneal epithelial resistance barrier regeneration.7 page(s