Pre-ischemic exercise reduces apoptosis in hippocampal CA3 cells after cerebral ischemia by modulation of the Bax/Bcl-2 proteins ratio and prevention of caspase-3 activation

Aerobic exercise attenuates LPS-induced cognitive dysfunction by reducing oxidative stress, glial activation, and neuroinflammation

Physical activity has been considered an important non-medication intervention in preserving mnemonic processes during aging. However, how aerobic exercise promotes such benefits for human health remains unclear. In this study, we aimed to explore the neuroprotective and anti-inflammatory effects of aerobic exercise against lipopolysaccharide (LPS)-induced amnesic C57BL/6J mice and BV-2 microglial cell models. In the in vivo experiment, the aerobic exercise training groups were allowed to run on a motorized treadmill 5 days/week for 4 weeks at a speed of 10 rpm/min, with LPS (0.1 mg/kg) intraperitoneally injected once a week for 4 weeks. We found that aerobic exercise ameliorated memory impairment and cognitive deficits among the amnesic mice. Correspondingly, aerobic exercise significantly increased the protein expressions of FNDC5, which activates target neuroprotective markers BDNF and CREB, and antioxidant markers Nrf2/HO-1, leading to inhibiting microglial-mediated neuroinflammation and reduced the expression of BACE-1 in the hippocampus and cerebral cortex of amnesic mice. We estimated that aerobic exercise inhibited neuroinflammation in part through the action of FNDC5/irisin on microglial cells. Therefore, we explored the anti-inflammatory effects of irisin on LPS-stimulated BV-2 microglial cells. In the in vitro experiment, irisin treatment blocked NF-κB/MAPK/IRF3 signaling activation concomitantly with the significantly lowered levels of the LPS-induced iNOS and COX-2 elevations and promotes the Nrf2/HO-1 expression in the LPS-stimulated BV-2 microglial cells. Together, our findings suggest that aerobic exercise can improve the spatial learning ability and cognitive functions of LPS-treated mice by inhibiting microglia-mediated neuroinflammation through its effect on the expression of BDNF/FNDC5/irisin.

Impact of Exercise Training on Survival Rate and Neural Cell Death in Sepsis Through the Maintenance of Redox Equilibrium

PURPOSE

Sepsis-related deaths occur during both the early proinflammatory and the late immunosuppressive phases of the condition. The balance of pro- and anti-inflammatory responses is influenced by damaged cells that die via either proinflammatory necroptosis or anti-inflammatory apoptosis. Both forms of cell death may be mediated by reactive oxygen species (ROS) generated during the proinflammatory response. Recent evidence suggests that exercise training boosts antioxidative capacity and could offer protection against sepsis. Given these findings, we aimed to examine the impact of exercise training on neural cell death in the context of sepsis.

METHODS

We assessed the effectiveness of exercise in reducing ROS production and the inflammatory response using a cecal ligation and puncture (CLP)-induced sepsis model. Forty C57BL/6N male mice were randomly divided into 2 groups: control (CLP-Con; n=20) and experimental (CLP-Ex; n=20). Before the induction of sepsis by CLP, the CLP-Ex mice underwent interval training on a treadmill 3 days per week for 8 weeks. Each day involved 10 cycles of 2 minutes at 8 m/min and 2 minutes at 15 m/min. After the CLP procedure, we monitored the survival of 10 mice from each group over a 30-hour period.

RESULTS

The findings indicated that exercise training increased the survival rate among mice with CLP-induced sepsis by enhancing antioxidative capacity and delaying the transition from a hyperdynamic to an immunosuppressive state.

CONCLUSION

Exercise training may delay the progression from the hyperdynamic state to the hypodynamic phase of sepsis by increasing antioxidant capacity and reducing apoptotic cell death.

Integrated transcriptome and metabolome analysis to investigate the mechanism of intranasal insulin treatment in a rat model of vascular dementia

Introduction: Insulin has an effect on neurodegenerative diseases. However, the role and mechanism of insulin in vascular dementia (VD) and its underlying mechanism are unknown. In this study, we aimed to investigate the effects and mechanism of insulin on VD. Methods: Experimental rats were randomly assigned to control (CK), Sham, VD, and insulin (INS) + VD groups. Insulin was administered by intranasal spray. Cognitive function was evaluated using the Morris's water maze. Nissl's staining and immunohistochemical staining were used to assess morphological alterations. Apoptosis was evaluated using TUNEL-staining. Transcriptome and metabolome analyses were performed to identify differentially expressed genes (DEGs) and differentially expressed metabolites (DEMs), respectively. Results: Insulin significantly improved cognitive and memory functions in VD model rats (p < 0.05). Compared with the VD group, the insulin + VD group exhibited significantly reduced the number of Nissl's bodies numbers, apoptosis level, GFAP-positive cell numbers, apoptosis rates, and p-tau and tau levels in the hippocampal CA1 region (p < 0.05). Transcriptomic analysis found 1,257 and 938 DEGs in the VD vs. CK and insulin + VD vs. VD comparisons, respectively. The DEGs were mainly enriched in calcium signaling, cAMP signaling, axon guidance, and glutamatergic synapse signaling pathways. In addition, metabolomic analysis identified 1 and 14 DEMs between groups in negative and positive modes, respectively. KEGG pathway analysis indicated that DEGs and DEMs were mostly enriched in metabolic pathway. Conclusion: Insulin could effectively improve cognitive function in VD model rats by downregulating tau and p-tau expression, inhibiting astrocyte inflammation and neuron apoptosis, and regulating genes involved in calcium signaling, cAMP signaling, axon guidance, and glutamatergic synapse pathways, as well as metabolites involved in metabolic pathway.

Involvement of TRPM2 Channel on Doxorubicin-Induced Experimental Cardiotoxicity Model: Protective Role of Selenium

Doxorubicin (DOXR) is an important chemotherapeutic drug used in cancer treatment for many years. Several studies reported that the use of DOXR increased toxicity by causing an increase in oxidative stress (OS), especially in the heart. In this study, we investigated the protective effect of selenium (Se) and the role of transient receptor potential melastatin-2 (TRPM2) channel activation by using N-(p-amylcinnamoyl) anthranilic acid (ACA) in a model of DOXR-induced cardiotoxicity. Sixty female rats were equally divided into the control, dimethyl sulfoxide (DMSO), DOXR, DOXR + Se, DOXR + ACA, and DOXR + Se + ACA groups. Glutathione (GSH), glutathione peroxidase (GSH-Px), caspases (Cas) 3 and 9, interleukin 1β (IL-1β), tumor necrosis factor-α (TNF-α), reactive oxygen species (ROS), poly [ADP-ribose] polymerase 1 (PARP-1), and TRPM2 channel levels were measured by ELISA. In addition, histopathological examination was performed in cardiac tissues and TNF-α, caspase 3, and TRPM2 channel expression levels were determined immunohistochemically. The levels of GSH, GSH-Px, caspases 3 and 9, IL-1β, TNF-α, ROS, PARP-1, and TRPM2 channel in serum, and cardiac tissue in the DOXR group were higher than in the control and DMSO groups (p < 0.05). However, these parameters in Se and/or ACA treatment groups were lower than in the DOXR group (p < 0.05). Also, we determined that Se and/or ACA treatment together with DOXR application decreased the TNF-α, Cas-3, and TRPM2 channel expression levels in the cardiac tissue. The data showed that administration of Se and/or ACA treatment together with DOXR may be used as a therapeutic agent in preventing DOXR-induced cardiotoxicity.

Preventive effect of quercetin-Loaded nanophytosome against autistic-like damage in maternal separation model: The possible role of Caspase-3, Bax/Bcl-2 and Nrf2

The autism is an abnormality in the neuronal advance which starts before age 3 recognized by defective behaviors. This study aimed to make quercetin-loaded nanophytosomes (QNP) on behavioral deficits, cerebellar oxidative stress and apoptosis in an autistic-like model caused by maternal separation (MS). The newborn rats are randomly categorized into seven groups, including control, positive control, disease, and diseases treated with quercetin (10 and 40 mg/kg) and QNP (10 and 40 mg/kg). Pups exposed to MS for 3 h per day from postnatal days (PND) 1-9 showed behavioral impairment in adult rats compared to control group. The oral administration of quercetin and QNP was constantly started after the lactation period (21 postnatal days) for three weeks. Autistic-like behaviors, antioxidant parameters, and Nrf2, Bax/Bcl-2, and Caspase-3 expressions were surveyed in the cerebellum. Quercetin (40 mg/kg) treated improved some behavioral disorders. Also, the improvement of oxidative stress parameters, Nrf2 and apoptotic factors gene expression was observed in the cerebellum of quercetin (40 mg/kg) treated (p < 0.01). QNP treatment (10 and 40 mg/kg) significantly ameliorated anxiety-like behaviors, line crossing, and grooming index (p < 0.001), lipid peroxidation (p < 0.001), and increased catalase (CAT) (p < 0.001), superoxide dismutase (SOD) (p < 0.001), glutathione peroxidase (GPx) (p < 0.001) activity, and glutathione (GSH) levels (p < 0.05). Moreover, QNP significantly reduced Caspase-3 and Bax expression (p < 0.001), but increased Bcl-2, and Nrf2 expressions (p < 0.001). These findings indicated that QNP due to its high bioavailability was more effective than quercetin can be reduced autistic-like behavior, oxidative and apoptotic damages in the model of MS rats.

Pre-ischemic exercise prevents inflammation and apoptosis by inhibiting MAPK pathway in ischemic stroke

Introduction

Mitogen-activated protein kinase (MAPK) pathway is a major mechanism of acute brain damage in ischemic stroke. Pre-ischemic exercise is an effective method to reduce ischemic injury. However, the regulation by pre-ischemic exercise of MAPK pathway and associated mechanisms in animal models remains unclear.

Materials and methods

In this study, Male SD rats were randomly divided into sham group, middle cerebral artery occlusion (MCAO) group, and exercise plus MCAO (EX + MCAO) group for 21 days, and then was established by MCAO. Longa score was used to measure neurological deficits at 0, 1, 2, and 3 days after MCAO. Hematoxylin and eosin staining was used to observe the brain injury. The expression of MAPK pathway was quantified by western blot. The M1 microglia protein was quantified by western blot and immunofluorescence, and the level of inflammatory factor was measured by enzyme-linked immunosorbent assay. TUNEL staining and western blot were used to measure apoptosis.

Results

In the current study, we observed that pre-ischemic exercise effectively decreased infarct volume, neurological deficit score and brain injury in MCAO rats through suppressing the activation of p-JNK and p-ERK1/2. Further investigation revealed that pre-ischemic exercise decreased M1 microglia activation and the serum level of TNF-α and IL-1β. In addition, the increased number of TUNEL-positive cells and Bax/Bcl-2 ratio also were reversed by pre-ischemic exercise.

Conclusions

Pre-ischemic exercise can alleviate inflammatory response and apoptosis by inhibiting the MAPK pathway in MCAO rats.

Melatonin attenuates cerebral hypoperfusion-induced hippocampal damage and memory deficits in rats by suppressing TRPM7 channels

This study was conducted to examine if modulating transporters like transient receptor potential cation channels, subfamily M, member 7 (TRPM7) underlies the hippocampal neuroprotection afforded by melatonin (Mel) in rats exposed to cerebral hypoperfusion (CHP). Experimental groups included control, Mel-treated (1.87 g/kg), CHP, and CHP + Mel (1.87 g/kg)-treated rats. CHP was induced by the permanent bilateral occlusion of the common carotid arteries (2VO) method and treatments were conducted for 7 days, orally. Mel prevented the damage of the dental gyrus and memory loss in CHP rats and inhibited the hippocampal reactive oxygen species (ROS), lipid peroxidation levels of tumor necrosis factor-α (TNF-α), interleukine-6 (IL-6), interleukine-1 beta (IL-1β), and prostaglandin E2 (PGE2). It also reduced the hippocampal transcription of the TRPM7 channels and lowered levels of calcium (Ca²⁺) and zinc (Zn²⁺). Mel Also enhanced the levels of total glutathione (GSH) and superoxide dismutase (SOD) in the hippocampus of the control and CHP-treated rats. In conclusion, downregulation of TRPM7 seems to be one mechanism underlying the neuroprotective effect of Mel against global ischemia and is triggered by its antioxidant potential.

Mechanisms of Preconditioning Exercise-Induced Neurovascular Protection in Stroke

Ischemic stroke is a leading cause of death and disability. Tissue plasminogen activator is the only U.S. Food and Drug Administration approved thrombolytic therapy for ischemic stroke patients till date. However, its use is limited due to increased risk of bleeding and narrow therapeutic window. Most of the preclinically tested pharmacological agents failed to be translated to the clinic. This drives the need for alternative therapeutic approaches that not only provide enhanced neuroprotection, but also reduce the risk of stroke. Physical exercise is a sort of preconditioning that provides the body with brief ischemic episodes that can protect the body from subsequent severe ischemic attacks like stroke. Physical exercise is known to improve cardiovascular health. However, its role in providing neuroprotection in stroke is not clear. Clinical observational studies showed a correlation between regular physical exercise and reduced risk and severity of ischemic stroke and better outcomes after stroke. However, the underlying mechanisms through which prestroke exercise can reduce the stroke injury and improve the outcomes are not completely understood. The purpose of this review is to: demonstrate the impact of exercise on stroke outcomes and show the potential role of exercise in stroke prevention and recovery; uncover the underlying mechanisms through which exercise reduces the neurovascular injury and improves stroke outcomes aiming to develop novel therapeutic approaches.

Exercise Factors Released by the Liver, Muscle, and Bones Have Promising Therapeutic Potential for Stroke

Stroke is one of the leading causes of death and disability in the world. Stroke not only affects the patients, but also their families who serve as the primary caregivers. Discovering novel therapeutic targets for stroke is crucial both from a quality of life perspective as well as from a health economic perspective. Exercise is known to promote neuroprotection in the context of stroke. Indeed, exercise induces the release of blood-borne factors that promote positive effects on the brain. Identifying the factors that mediate the positive effects of exercise after ischemic stroke is crucial for the quest for novel therapies. This approach will yield endogenous molecules that normally cross the blood brain barrier (BBB) and that can mimic the effects of exercise. In this minireview, we will discuss the roles of exercise factors released by the liver such as beta-hydroxybutyrate (DBHB), by the muscle such as lactate and irisin and by the bones such as osteocalcin. We will also address their therapeutic potential in the context of ischemic stroke.

Treadmill Exercise during Pregnancy Decreased Vulnerability to Neonatal Hypoxia-Ischemia through Reducing Inflammation and Increasing Antiapoptotic Gene Expressions and Antioxidant Capacity in Rats

Background

The purpose of present study was to assess the impact of maternal treadmill exercise during pregnancy on inflammation, oxidative stress, expression of Bax and Bcl-2 genes, and brain-derived neurotrophic factor (BDNF) level in neonatal rat brain after the hypoxia-ischemia injury. Material and Methods. A total of 24 female Wistar rats were utilized in this research. Two groups are randomly considered for rats: (1) not exercised through pregnancy and (2) exercised during pregnancy. Offsprings were divided into four groups including after delivery: (1) sham, (2) sham/exercise (sham/EX), (3) HI, and (4) HI+exercise. HI was induced in pups at postnatal day 8. Neurobehavioral tests were done seven days after HI induction. Then, the brain tissue was taken from the skull to estimate Bcl-2 and Bax gene expressions, BDNF, cerebral edema, infarct volume, inflammatory factors, oxidative stress, and neurological function.

Results

The BDNF level in the HI+exercise group was considerably higher than the HI, sham, and sham/EX groups. Tumor necrosis factor (TNF-α), C-reactive protein (CRP), and the whole oxidant capacity (TOC) levels in the HI group were significantly higher than the sham and sham/EX groups. TNF-α, CRP, and TOC levels in the HI+exercise group were significantly lower than the HI group. Total antioxidant capacity (TAC) level in the HI+exercise group was significantly higher than the HI group. Infarct volume and edema percent in the HI+exercise group were significantly lower than the HI group. Neurological function in the HI+exercise group was significantly better than the HI group. Bax expression in the HI+exercise group was significantly lower than the HI group. Bcl-2 expression in the HI+exercise group was significantly higher than the HI group. In the sham group, BDNF, TNF-α, CRP, TAC, TOC, edema levels, and neurological function had no significant difference with the sham/EX group.

Conclusion

It appears that the maternal treadmill exercise during pregnancy exerts a supportive impact against neonatal HI brain injury through increasing antioxidant capacity, Bcl-2 expression, and BDNF levels and decreasing inflammation that is resulted in the lower infarct volume and sensorimotor dysfunction.

Bag-1L Protects against Cell Apoptosis in an In Vitro Model of Lung Ischemia-Reperfusion Injury through the C-Terminal "Bag" Domain

Bcl-2-associated athanogene 1 (Bag-1) is a multifunctional and antiapoptotic protein that binds to the antiapoptosis regulator Bcl-2 and promotes cell survival. To investigate the protective function of Bag-1, we examined the effects of Bag-1L, one isoform of Bag-1, in an in vitro cell culture model of lung ischemia-reperfusion injury (LIRI) generated by treatment of A549 cells with hypoxia/reoxygenation. Overexpression of full-length Bag-1L increased the viability of A549 cells and reduced cell apoptosis in response to 6 h of hypoxia/reoxygenation treatment. Furthermore, Bag-1L overexpression enhanced the heat shock protein 70 (HSP70) and Bcl-2 protein levels, increased the phosphorylation of AKT, decreased Bax and cleaved caspase-3 levels, and was able to overcome cell cycle arrest. These effects were not observed in A549 cells overexpressing a truncated form of Bag-1L lacking the "Bag domain," denoted Bag-1L△C. The "Bag domain" is the C-terminal 47 amino acids. Taken together, the results of this study suggest that Bag-1L overexpression can protect against oxidative stress and apoptosis in an in vitro LIRI model, with a dependence on the Bag domain.

Anti-apoptotic effect of silymarin-loaded chitosan nanoparticles on hippocampal caspase-3 and Bcl-2 expression following cerebral ischemia/reperfusion injury

BACKGROUND

Cerebral ischemia/reperfusion (I/R) causes memory and learning impairments and apoptosis in the hippocampus. The aim of present study aimed to investigate the anti-apoptotic effects of silymarin-loaded chitosan nanoparticles (SM-CS-NPs) on the expression of Bcl-2 and Caspase-3 genes in hippocampal neurons after I/R injury.

MATERIAL AND METHODS

SM and SM-CS-NPs were orally administered (15 mg/kg) for 14 days, and then cerebral I/R injury was induced by the bilateral common carotid artery occlusion (BCCAO). One day after I/R induction, memory and learning impairments and various biochemical estimations were assessed.

RESULTS

Our results indicated that SM-CS-NPs improved I/R-induced memory and learning impairments and oxidative damage in the hippocampal region. The qRT-PCR analysis indicated that SM-CS-NPs pretreatment inhibited I/R-induced neuronal apoptosis by increasing the expression of Bcl-2 and decreasing the expression of Caspase-3 in the hippocampus.

CONCLUSION

These findings suggest that SM-CS-NPs exert neuroprotective effects, and the neuroprotection is likely to be associated with the regulation of Bcl-2 and Caspase-3, leading to inhibition of apoptotic cell death in hippocampal neurons.

Protective effect of hypoxia inducible factor-1α gene therapy using recombinant adenovirus in cerebral ischaemia-reperfusion injuries in rats

Context: Hypoxia-inducible factor-1α (HIF-1α)-induced genes can improve blood circulation.Objective: To investigate brain protective effect of recombinant adenovirus-mediated HIF-1α (AdHIF-1α) expression and its mechanism.Materials and methods: Male SD rats were used to establish focal cerebral ischaemia-reperfusion (CIR) injury models and randomly divided into normal, sham, CIR, Ad and AdHIF-1α groups. Ad or AdHIF-1α (10⁸ pfu/10 µL) were administered into lateral ventricle of rats in Ad and AdHIF-1α groups. Modified neurological severity score (mNSS), brain water content (BWC) and cerebral infarct volumes (CIVs) were analyzed, and HE staining was performed using the brain tissues. Furthermore, the expression of caspase-3 and HSP90 was analyzed using qRT-PCR and Western blotting.Results: Compared to CIR (mNSS, 8.52 ± 0.52; CIV, 0.22 ± 0.01) and Ad groups (mNSS, 8.83 ± 0.41; CIV, 0.22 ± 0.02), mNSS and CIV were significantly decreased in AdHIF-1α group (mNSS, 6.03 ± 0.61; CIV, 0.11 ± 0.01) at 72 h (p < 0.05). With prolonged reperfusion time (6 h to 72 h), BWC of all rats increased gradually, although the increase was markedly less in AdHIF-1α group (78.15 ± 0.16 to 87.01 ± 0.31) compared to that in CIR (78.77 ± 0.60 to 89.74 ± 0.34) and Ad groups (78.77 ± 0.35 to 89.71 ± 0.27) (p < 0.01). There were significantly greater pathological changes in the neurons in AdHIF-1α group at 72 h following CIR. Furthermore, expression of caspase-3 (p < 0.01) down-regulated and HSP90 up-regulated (p < 0.05) at mRNA and protein levels in AdHIF-1α group.Discussion and conclusions: HIF‑1α gene therapy is neuroprotective towards the CIR rat model. HIF-1α may be a candidate gene for the treatment of ischaemic brain injury.

Comparison of the protective effects of curcumin and caffeic acid phenethyl ester against doxorubicin-induced testicular toxicity

Whether testicular toxicity is mediated by matrix metalloproteinases (MMPs) is an important question that has not been examined. This study investigated the suppressive effect of curcumin and caffeic acid phenethyl ester (CAPE) on oxidative stress, apoptosis, and whether MMPs mediate doxorubicin (DOX)-induced testicular injury. Male rats were randomly divided into eight groups (n = 8 per group). The groups were as follows: sham, dimethyl sulphoxide (100 µL), DOX (3 mg/kg), CAPE (2.68 mg/kg), curcumin (30 mg/kg), DOX+CAPE (3 mg/kg DOX and 2.68 mg/kg CAPE), DOX+curcumin (3 mg/kg DOX and 30 mg/kg curcumin) and DOX+CAPE+curcumin (3 mg/kg DOX, 2.68 mg/kg CAPE and 30 mg/kg curcumin). Injections were administered daily for 21 days. The oxidative stress, MMPs, proinflammatory cytokines and apoptotic markers in the DOX group were higher than the sham group (p < .05); these measures were lower in the groups treated with CAPE and curcumin together with DOX compared with the DOX group (p < .05). The results showed that MMPs mediated DOX-induced testicular injury, but CAPE and especially curcumin suppressed testis injury and cell apoptosis by suppressing DOX-induced increases in MMPs, oxidative stress and proinflammatory cytokines. However, curcumin exhibited more pronounced effects than CAPE in terms of all studied parameters.

Usnic acid improves memory impairment after cerebral ischemia/reperfusion injuries by anti-neuroinflammatory, anti-oxidant, and anti-apoptotic properties

Objective(s):

Cerebral ischemia/reperfusion causes complex pathological mechanisms that lead to brain tissue damage. Usnic acid is a lichen secondary metabolite that has many different biological properties including anti-inflammatory and anti-oxidant activities. Therefore, the objective of the current study was to investigate the neuroprotective effects of usnic acid on apoptotic cell death, neuroinflammation, anti-oxidant enzyme activities, and oxidative stress levels after transient cerebral ischemia/reperfusion.

Materials and Methods:

Forty-two male Wistar rats were randomly assigned to three groups (sham, ischemia/reperfusion, and ischemia/reperfusion+usnic acid). Ischemia was induced by 20 min occlusion of common carotid arteries. Injection of usnic acid (25 mg/kg, intraperitoneally) and saline was done at the beginning of reperfusion time. Morris water maze was applied to assess spatial memory. The protein expression amount was measured using immunohistochemical and immunofluorescence staining. Spectrophotometric assay was performed to determine the levels of anti-oxidant enzymes.

Results:

Usnic acid significantly reduced caspase-3, glial fibrillary acidic protein- positive and ionized calcium-binding adaptor molecule 1-positive cells (P<0.001) and enhanced spatial memory disorders (P<0.05) due to brain ischemia. In addition, treatment with usnic acid improves effects in the antioxidant system following cerebral ischemia (P<0.05).

Conclusion:

Our findings indicate that usnic acid has neuroprotective properties, which possibly is applicable as a promising candidate for cerebral injuries caused by ischemia.

The effect of preconditioning with high-intensity training on tissue levels of G-CSF, its receptor and C-kit after an acute myocardial infarction in male rats

BACKGROUND

Exercise training is known as a practical way to increase cardioprotection against stress, and it seems that stem cell recruitment is one of its mechanisms. The purpose of the present study was to investigate the effect of preconditioning with High-intensity interval training (HIIT) on tissue levels of G-CSF, its receptor and C-Kit following acute myocardial infarction in male rats.

METHODS

Twenty Male Wistar rats were randomly divided into 4 groups of control, MI, HIIT, and HIIT+MI. Training groups performed 2 weeks of high intensity interval training in 4 sections. The first section consisted training in 3 days and 2 sessions in each day (4 × 2 min with 35-40 m/min and 3 × 2 min with 25-30 m/min between high intervals. The second part included 2 days of training (4 × 2 min with 40 to 45 m/min and 3 × 2 min with 28 to 32 m /min). The third part was performed in 3 days with one more repetition. The fourth section consisted 2 days of training and with one more repetition compared to section 3. For induction of myocardial infarction, subcutaneous injection of isoprenaline was used. CK, total CK, LDH, and troponin T were measured in serum and G-CSF, G-CSFR and C-Kit proteins were measured by the Western Blot method in the heart tissue.

RESULTS

The results of this study showed that enzymes of CK, total CK, LDH, troponin T had a significant increase in both MI and HIIT+MI groups compared to the other two groups (P < 0.001) and these indices in the MI group were significantly higher than the HIIT+MI group. Also, the results demonstrated that G-CSF, G-CSFR and C-Kit protein expression in the heart tissue significantly increased after MI. As well as, 2 weeks of HIIT training significantly increased G-CSF and C-kit in the training group compared to the control group, but the training caused that these proteins does not increase in HIIT+MI group as much as MI group.

CONCLUSIONS

Along with other protective pathways, high intensity interval training can increase cardioprotection and decrease heart injuries through the increase in G-CSF, G-CSFR and C-kit level.

Effects of preconditioning exercise on nitric oxide and antioxidants in hippocampus of epileptic seizure

The mechanism of epileptic seizure has not been identified clearly. Exercise can play a role of antioxidants against oxidative stress. In the present study, the neuroprotective effects of preconditioning exercise on epileptic seizure were investigated with focusing on antioxidants activity in the hippocampus. Rats were allocated to the following groups: saline control group, kainic acid control group, and previous exercise and kainic acid group. Rats in the previous exercise and kainic acid group were subjected to treadmill exercise 5 days a week for 4 weeks. After 48 hr of exercise period, rats in the kainic acid control group and previous exercise and kainic acid group were injected with kainic acid. The number of neuronal nitric oxide synthase-positive cells and the level of nitrite in hippocampus were increased and the expressions of superoxide dismutase-1, superoxide dismutase-2, and catalase in hippocampus were reduced in kainic acid control group compared with saline control group. By contrast, in the previous exercise and kainic acid group, the number of neuronal nitric oxide synthase-positive cells and the level of nitrite were decreased and the expressions of superoxide dismutase-1, superoxide dismutase-2, and catalase were increased compared with the kainic acid control group. Preconditioning exercise may have neuroprotective effects against oxidative stress via increased antioxidant activity in the hippocampus of epileptic seizure.

Modulating effects of preconditioning exercise in the expression of ET-1 and BNP via HIF-1α in ischemically injured brain

It is well-known that in ischemia-induced hypoxia, hypoxia-inducible factor -1α (HIF-1α) is critical in triggering expression of its downstream target genes to produce several products, such as erythropoietin (EPO), vascular endothelial growth factor (VEGF), nitric oxide synthesis (NOS), glucose transportor-1 (GLUT-1), insulin-like growth factor (IGF), which further promote erythropoiesis, angiogenesis, vasodilation and capitalization of glucose to overcome hypoxia. Meanwhile, as the factors with opposite effects on blood vessels, endothelin-1 (ET-1) and brain natriuretic peptide (BNP) also stand out strikingly in ischemic pathophysiology. To this day, several preconditioning manners have been used to induce tolerance to ischemia. During our research, exercise preconditioning was applied and it was demonstrated that HIF-1α triggered expression of ET-1 and BNP, which confirmed their downstream target genes for HIF-1α. And ET-1 may influcence expression of BNP to some degree but not the only factor which regulates BNP expression. Therefore, our findings suggest exercise preconditioning may provide protection to the ischemic brain tissue via HIF-1α which in turn increases expression of BNP to cause vasodilation in cooperation with some other factors, such as VEGF and EPO, to increase the blood flow in the ischemic area and then relieve the injuries induced by ischemia.

PET imaging of cardiomyocyte apoptosis in a rat myocardial infarction model

Cardiomyocyte apoptosis has been observed in several cardiovascular diseases and contributes to the subsequent cardiac remodeling processes and progression to heart failure. Consequently, apoptosis imaging is helpful for noninvasively detecting the disease progression and providing treatment guidance. Here, we tested ¹⁸F-labeled 2-(5-fluoropentyl)-2-methyl-malonic acid (¹⁸F-ML-10) and ¹⁸F-labeled 2-(3-fluoropropyl)-2-methyl-malonic acid (¹⁸F-ML-8) for apoptosis imaging in rat models of myocardial infarction (MI) and compared them with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG). MI was induced in Sprague-Dawley rats by permanent left coronary artery ligation. Procedural success was confirmed by echocardiography and positron emission tomography (PET) imaging with ¹⁸F-FDG. In vivo PET imaging with ¹⁸F-ML-10 and ¹⁸F-ML-8 was performed in the MI models at different time points after operation. Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assays and immunohistochemical analyses were used to evaluate myocardial apoptosis. In vitro cell binding assays were performed to validate ¹⁸F-ML-8 binding to apoptotic cardiomyocytes. PET imaging demonstrated high ¹⁸F-ML-10 and ¹⁸F-ML-8 uptake where ¹⁸F-FDG uptake was absent. The focal accumulation of the two tracers was high on days 1 and 3 but was not notable on days 5 and 7 after surgery. The infarct-to-lung uptake ratio was 4.29 ± 0.30 for ¹⁸F-ML-10 and 3.51 ± 0.18 for ¹⁸F-ML-8 (n = 6, analyzed by averaging the uptake ratios on postoperative days 1 and 3, P < 0.05). The TUNEL results showed that myocardial cell apoptosis was closely related to the focal uptake of the apoptotic tracers in the infarct area. In addition, the apoptosis rates calculated from the TUNEL results were better correlated with ¹⁸F-ML-8 uptake than with ¹⁸F-ML-10 uptake. Ex vivo cell binding assays demonstrated that ¹⁸F-ML-8 accumulated in apoptotic cells but not in necrotic or normal cells. PET imaging using ¹⁸F-ML-10 or ¹⁸F-ML-8 allows the noninvasive detection of myocardial apoptosis in the early phase. In addition, ¹⁸F-ML-8 may be better than ¹⁸F-ML-10 for apoptosis imaging. We propose that PET imaging with ¹⁸F-ML-10 or ¹⁸F-ML-8 combined with ¹⁸F-FDG is an alternative for detecting and assessing MI.

Endogenous neuroprotective potential due to preconditioning exercise in stroke

Stroke is a leading cause of serious long-term physical disability due to insufficient neurorepair mechanisms. In general, physical activity is an important modifiable risk factor, particularly for stroke and cardiovascular diseases. Physical exercise has shown to be neuroprotective in both animal experiments and clinical settings. Exercise can be considered a mild stressor and follows the prototypical preconditioning stimulus. It has beneficial effects on brain health and cognitive function. Preconditioning exercise, which is prophylactic exercise prior to ischemia, can protect the brain from subsequent serious injury through promotion of angiogenesis, mediation of inflammatory responses, inhibition of glutamate over-activation, protection of the blood-brain barrier, and inhibition of apoptosis. Preconditioning exercise appears to induce brain ischemic tolerance and it has been shown to exert beneficial effects. It is clinically safe and feasible and represents an exciting new paradigm in endogenous neuroprotection for patients with acute stroke. In this review, we describe the neuroprotective potential of preconditioning exercise and clinical applications in patients with acute ischemic stroke.

Protective Effects of Nucleobinding-2 After Cerebral Ischemia Via Modulating Bcl-2/Bax Ratio and Reducing Glial Fibrillary Acid Protein Expression

Introduction

Nucleobinding-2 (NUCB2) or nesfatin-1, a newly identified anorexigenic peptide, has antioxidant, anti-inflammatory, and anti-apoptotic properties. Brain ischemiareperfusion induces irreversible damages, especially in the hippocampus area. However, the therapeutic effects of NUCB2 have not been well investigated in cerebral ischemia. This study was designed for the first time to investigate the protective effects of NUCB2/Nesfatin-1 on the expression of apoptosis-related proteins and reactive astrogliosis level in the CA1 area of hippocampus in an experimental model of transient global cerebral ischemia.

Methods

The male Wistar rats were randomly allocated into 4 groups (sham, NUCB2, ischemia-reperfusion, and ischemia-reperfusion+NUCB21) (n =7). The model of cerebral ischemia was prepared by common carotid arteries occlusion for 20 minutes. Nesfatin-1 (20 μg/kg) and saline (as a vehicle) were injected (intraperitoneally) at the beginning of the reperfusion period. The assessment of the protein expression levels was performed by immunofluorescence and immunohistochemical staining.

Results

NUCB2 significantly reduced the Bax and GFAP protein levels in the CA1 area after ischemia (P<0.05). Also, NUCB2 increased Bcl-2 protein level (P<0.05). NUCB2 exerted protective effects against ischemic injury by the inhibition of astrocytes activation as an inflammatory response and decreased neuronal cell apoptosis.

Conclusion

The present study provides the possible neuroprotective view of nesfatin-1 in the treatment of ischemia injury model in rat hippocampus.

Tetrahydroxystilbene Glucoside Suppresses NAPDH Oxidative Stress to Mitigate Apoptosis and Autophagy Induced by Cerebral Ischemia/Reperfusion Injury in Mice

Tetrahydroxystilbene glucoside (TSG) is the active ingredient extracted from the traditional Chinese medicine Fallopia multiflora, which has extensive pharmacological activities. The current study aimed to observe the neuroprotective mechanism of TSG in the ischemia/reperfusion (I/R) brain injury-induced apoptosis and autophagy from the point of view of oxidative stress (OS). The middle cerebral artery occlusion (MCAO) model was prepared through the suture-occluded method, and TSG was administered through tail vein injection at the time of reperfusion at the doses of 3.0, 6.0, and 12.0 mg/kg. Compared with sham group, the neurological score in I/R mice was increased (P<0.05), along with remarkably elevated cerebral infarct volume (P<0.05); while TSG administration could reduce the neurological score and cerebral infarct volume (P<0.05) and improve the neuronal damage in ischemic cortex and hippocampus (P<0.05). The expression of NOX4, activated caspase-3(9), and Beclin 1 (P<0.05), as well as the LC3BII/I ratio, had been markedly elevated (P<0.05), while TSG administration could effectively suppress the expression of the above-mentioned proteins (P<0.05). In conclusion, TSG shows obvious protection against brain injury in I/R mice, and its mechanism may be related to suppressing the NADPH-induced OS and reducing neuronal apoptosis as well as autophagy.

Preischemic treadmill exercise improves short-term memory by inhibiting hypoperfusion-induced disruption of blood-brain barrier after bilateral common carotid arteries occlusion

Bilateral common carotid arteries occlusion (BCCAO) causes an abrupt reduction of cerebral blood flow, and this method has been used to investigate the effects of chronic cerebral hypoperfusion on vascular dementia and neuronal injuries. Chronic cerebral hypoperfusion leads to functional changes in the hippocampus and then results in a cognitive impairment. We investigated the effect of preischemic treadmill exercise on short-term memory and blood-brain barrier integration following cerebral hypoperfusion caused by BCCAO. The rats in the preischemic treadmill exercise and BCCAO group were made to run on a treadmill for 30 min once a day for 4 weeks. At 4 weeks after performing treadmill exercise, right carotid artery was ligated, and 1 week after, left common carotid artery was ligated. At 20 days after BCCAO, short-term memory was evaluated. Half of the rats were sacrificed 2 days after BCCAO and the other rats were sacrificed at 3 weeks after BCCAO. Immunohistochemistry and western blot were performed. Preischemic treadmill exercise alleviated impairment of short-term memory in the step-down avoidance task. Preischemic treadmill exercise reduced microvascular injury in the hippocampus. Preischemic treadmill exercise prevented the reduction of zonula occludens-1 in the hippocampus and inhibited the activation of matrix metalloproteinase-9. Therefore, pre-conditioning treadmill exercise might be used as a therapeutic strategy for the prevention of stroke in patients.

The balance of apoptosis and autophagy via regulation of the AMPK signal pathway in aging rat striatum during regular aerobic exercise

The objective was to analyze the effects of aerobic exercise on aging striatum stress resistance, and the adaptive mechanisms related to neurodegenerative diseases, and the occurrence, and development of neural degeneration. The 10-weeks of regular moderate-intensity aerobic exercise intervention were carried out in the aerobic exercise runner Sprague-Dawley rats. Apoptotic nuclei appeared in the striatum of aged rats, showing a tendency to relate to aging. The apoptotic index of the striatum in young, middle-aged, and old-aged rats of the aerobic exercise groups increased by 205.56%, 57%, and 68.24%. Autophagy markers Beclin l and LC 3-II expression, AMPKα1 and pAMPKα1 expression increased significantly in all age-exercise groups. The ratio of AMPKα1/pAMPKα1 increased after exercise, and the tendency of exercise to alter autophagy and cell apoptosis increased with aging. Then SirT2 mRNA was significantly upregulated in the aerobic exercise runner groups. In conclusion, we showed that the balance of autophagy and apoptosis were closely regulated by regular aerobic exercise, which affected the development of aging, and via regulation of the AMPK/SirT2 signaling pathway.

Neuroprotective effects of different frequency preconditioning exercise on neuronal apoptosis after focal brain ischemia in rats

OBJECTIVE

Preconditioning exercise can exert neuroprotective effects after stroke; however, the effects of exercise intensity, frequency, duration are unknown. We investigated the neuroprotective effect of different frequency preconditioning exercise on neuronal apoptosis after cerebral ischemia in rats.

METHODS

Rats were divided into the following five groups: 5 times a week of exercise (5/w-Ex) group, 3 times a week of exercise (3/w-Ex) group, once a week of exercise (1/w-Ex) group, no exercise (No-Ex) group, and intact control (control) group. Rats were made to run on a treadmill for 30 min per day at a speed of 25 m/min for 3 weeks. After the running program, the rats were subjected to 60-min left middle cerebral artery occlusion. Two days after ischemia, the cerebral infarct volume, neurological and motor function, Bcl-2-associated X protein (Bax)/B-cell lymphoma 2 (Bcl-2) ratio, expression of caspase-3, and TUNEL positive cells were examined in the cerebral cortex surrounding the ischemic zone.

RESULTS

The 3/w-Ex and 5/w-Ex groups showed significantly reduced infarct volumes compared with the No-Ex group, but the 1/w-Ex group did not. In addition, the 3/w-Ex and 5/w-Ex groups had improved neurological scores and sensorimotor function compared with the No-Ex group. The Bax/Bcl-2 ratio, expression of caspase-3, and TUNEL-positive cells significantly decreased in the penumbra area in the 3/w-Ex or 5/w-Ex groups compared with the No-Ex group.

DISCUSSION

Our findings suggested that three times or more per week of high-intensity preconditioning exercise exert neuroprotective effects through the downregulation of the Bax/Bcl-2 ratio and caspase-3 activation after stroke.

ABBREVIATIONS

TUNEL: terminal deoxynucleotidyl transferase-mediated biotinylated dUTP nick and labeling; MCAO:middle cerebral artery occlusion; BAX:Bcl-2-associated X protein; Bcl-2: B-cell lymphoma 2; TTC: 2,3,5-triphenyltetrazorlium chloride.

Effect of intravenous injection of antagomiR-1 on brain ischemia

Stroke is one of the leading causes of death in the world, but the underlying molecular mechanism of this disease remains elusive, thus it will be great challenges to finding appropriate protection. MicroRNAs are short, single-stranded, non-coding RNAs and recent studies have shown that they are aberrantly expressed in ischemic condition. Due to the fact that miR-1 has harmful effects on neural damages during brain ischemia, limited miR-1 has been proven to be protective in middle cerebral artery occlusion (MCAO). Here, the possible positive effect of intravenous injection of antagomiR-1 as a post-ischemic treatment on neurological deficits, infarct volume, brain edema and blood-brain barrier (BBB) permeability was evaluated. The rats were divided randomly into three experimental groups, each with 21 animals. MCAO surgery was performed on all groups and one hour later, 0.1 ml normal saline, 0.1 ml rapamycin and 300 pmol/g miR-1 antagomir (soluble in 0.1 ml normal saline), were injected intravenously into control, positive control and treatment group, respectively. After 24 h, neurologic deficits score, infarct volume, brain edema and BBB permeability were measured. The results indicated that post-treatment with miR-1 antagomir significantly improved neurological deficits and reduced infarction volume, brain edema, and BBB permeability. These data proved that there is a positive effects of antagomiR-1 on ischemic neuronal injury and neurological impairment. Due to the fact that microRNAs are able to protect the brain, it would be a promising therapeutic approach to stroke treatment.

Protective effects of Nesfatin-1 peptide on cerebral ischemia reperfusion injury via inhibition of neuronal cell death and enhancement of antioxidant defenses

Nesfatin-1 is a novel peptide with anorexigenic and anti-hyperglycemic properties. According to previous studies, this multi-functional peptide protects dopaminergic cells against neurotoxicity via anti-apoptotic effects. In addition, Nesfatin-1 protects myocardial tissue after myocardial infarction via anti-inflammatory and anti-apoptotic mechanisms. In this study, we investigated the neuroprotective effects of nesfatin-1 against cerebral ischemia reperfusion injury in the CA1 area of hippocampus in rats. 56 male Wistar rats (240-270 g) were randomly selected and allocated into four groups: (1) sham, (2) nesfatin-1, (3) ischemia/reperfusion, (4) ischemia/reperfusion+nesfatin-1. Cerebral ischemia induced by the occlusion of the common carotid arteries for 20 min was followed by reperfusion. Saline as a vehicle and nesfatin-1 (20 μg/kg) were injected intraperitoneally (IP) at the start of cerebral reperfusion. Apoptotic and necrotic cell death was detected by TUNEL and Nissl staining. Malondialdehyde (MDA) and antioxidant enzymes (GSH and SOD) levels were measured by the ELISA method. The results showed that cerebral ischemia increased the apoptotic and necrotic cell death in the CA1 area of hippocampus, while, treatment with nesfatin-1significantly reduced apoptotic and necrotic cell death. Moreover, the MDA levels of the hippocampus in ischemic rats were higher, whereas in nesfatin-1-treated rats the MDA levels were decreased. Furthermore, the SOD and GSH levels in the ischemic rats were decreased, whilst in ischemic rats treated with nesfatin-1, the SOD and GSH levels were increased. This study for the first time found that nesfatin-1 treatment improves CA1 hippocampus injuries after cerebral ischemia through preventing neuronal cell death and enhancement of antioxidant defenses.

Long-term exposure to low level of fluoride induces apoptosis via p53 pathway in lymphocytes of aluminum smelter workers

Long-term occupational exposure to low level of fluoride can induce oxidative stress and apoptosis in many cells, including lymphocyte. However, the underlying mechanism remains unclear. Hence, this study was designed to explore the potential oxidative stress and apoptosis of long-term occupational exposure to low level of fluoride in aluminum smelter workers. A total of 120 aluminum smelter workers were recruited in control, low-, middle-, and high-fluoride exposure groups with 30 workers for each group. The peripheral blood samples were collected, centrifuged, and isolated to obtain serum and lymphocyte suspensions. The air and serum fluoride concentrations were detected by fluoride ion-selective electrode method. The lymphocytic apoptosis rate, DNA damage, oxidative stress, and mRNA levels of p53, Bcl-2, and Bax were assessed by Annexin V/PI staining, comet assay, attenuated total reflectance Fourier transform infrared spectroscopy and real-time polymerase chain reaction, respectively. Results showed that the air and serum fluoride concentrations of fluoride-exposed groups were higher than those of the control group (p < 0.05). Fluoride exposure might induce apoptosis, DNA damage and oxidative stress in a dose-dependent manner in lymphocytes (p < 0.05). The expression levels of p53 and Bax were increased with fluoride exposure in lymphocytes (p < 0.05), whereas the Bcl-2 expression was decreased but not significantly. Taken together, these observations indicate that long-term occupational exposure to low level of fluoride may lead to oxidative stress and induce apoptosis through the p53-dependent pathway in peripheral blood lymphocytes of aluminum smelter workers. Serum fluoride level may be the potential biomarker of fluoride exposure.

Preconditioning exercise reduces brain damage and neuronal apoptosis through enhanced endogenous 14-3-3γ after focal brain ischemia in rats

14-3-3γ is an important early ischemia-inducible protective factor against ischemic cell death in cerebral cortical neurons. We investigated the anti-apoptosis mechanism of enhanced 14-3-3γ mediated by preconditioning exercise-induced brain ischemic tolerance after stroke. Rats were assigned to four groups: exercise and ischemia (Ex group), ischemia and no exercise (No-Ex group), exercise and no ischemia (Ex-only group), and no exercise and ischemia (control group). Rats were trained on a treadmill for 5 days a week for 3 weeks (running speed, 25 m/min; running duration, 30 min/day). After the exercise program, stroke was induced by left middle cerebral artery occlusion. The infarct volume, neurological deficits, and motor function, as well as expression levels of hypoxia-induced factor-1α (HIF-1α), 14-3-3γ, P2X7 receptors, p-β-catenin Ser37, Bax, and caspase 3 were evaluated by immunohistochemistry and western blotting. The expression of HIF-1α and 14-3-3γ significantly increased in neurons and astrocytes in the Ex-only group. HIF-1α was co-expressed with P2X7 receptor- and GFAP-positive astrocytes. After stroke, the Ex group had significantly reduced brain infarction. HIF-1α and 14-3-3γ significantly increased in the Ex group compared to the No-Ex group. In addition, p-β-catenin Ser37 significantly increased following elevated 14-3-3γ; in contrast, Bax and caspase 3 were significantly reduced in the Ex group. Our findings suggest that preconditioning exercise prior to ischemia induces neuron- and astrocyte-mediated brain ischemic tolerance through increased expression of HIF-1α and 14-3-3γ, which are intrinsic protective factors; the upregulated 14-3-3γ induced by preconditioning exercise reduces ischemic neuronal cell death through the 14-3-3γ/p-β-catenin Ser37/Bax/caspase 3 anti-apoptotic pathway.

The role of adenosine in up-regulation of p38 MAPK and ERK during limb ischemic preconditioning-induced brain ischemic tolerance

Our previous studies have demonstrated that limb ischemic preconditioning (LIP) induced brain ischemic tolerance and up-regulated the expression of p38 MAPK and ERK in the hippocampal CA1 region in rats. The present study was undertaken to investigate the role of adenosine in brain protection and up-regulation of p38 MAPK and ERK induced by LIP. It was found that adenosine A1 receptor antagonist DPCPX dose-dependently inhibited the protective effect of LIP. The up-regulation of p38 MAPK and ERK induced by LIP could be blocked by DPCPX. Furthermore, we observed the effect of adenosine on the brain ischemia. The results showed that pre-administration of adenosine could partly mimic the neuroprotective effect on the brain, up-regulate the expression of p38 MAPK and ERK. Based on the above results, it can be concluded that adenosine participated in brain protection and up-regulation of the expression of p38 MAPK and ERK during the induction of brain ischemic tolerance after LIP.

Silencing of Xeroderma Pigmentosum Group D Gene Promotes Hepatoma Cell Growth by Reducing P53 Expression

BACKGROUND This study investigated the effect of xeroderma pigmentosum group D (XPD) silencing on the growth of hepatoma cells and assessed the mechanisms. MATERIAL AND METHODS XPD gene was silenced by siRNA in hepatoma cells. The experiments were randomly divided into a control group, a liposome control group, a negative control (NC) group, an XPD siRNA group, and an XPD siRNA + P53 inhibitor group. 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) was used to detect cell viability 24 h after gene silencing and treatments. Terminal deoxynucleotidyl transferases (TdT)-mediated dUTP nick-end labeling (TUNEL) and flow cytometry were used to detect apoptosis. Invasive ability was detected by Transwell assay. Additionally, the expression of mouse double-minute 2 homolog (Mdm2), mouse double-minute 4 homolog (Mdm4), CyclinD1, P21, Bax, P53, C-sis, and Bcl-2 was detected by real-time polymerase chain reaction and Western blotting. RESULTS Compared with the NC group, XPD siRNA significantly reduced XPD expression at both mRNA and protein levels. XPD siRNA significantly promoted cell proliferation, reduced apoptosis, and promoted cell invasive ability. Expression of CyclinD1, Bcl-2, and C-sis increased significantly after XPD silencing, while the expression of P21, Mdm2, Mdm4, Bax, and P53 significantly decreased (vs. NC, P<0.05). Importantly, P53 inhibitor (1 μM bpV) further enhanced the effect of XPD silencing (vs. XPD silencing, P<0.05). CONCLUSIONS Our data revealed that XPD silencing promoted growth of hepatoma cells by reducing P53 expression.

Effect of hydrogen-rich saline on apoptosis induced by hepatic ischemia reperfusion upon laparoscopic hepatectomy in miniature pigs

Hepatic ischemia reperfusion injury (HIRI) occurs commonly in liver surgery and liver transplantation. Hydrogen, a safe and effective antioxidant, exerts a protective effect against liver injury. In this study, we investigated the role of hydrogen-rich saline (HRS) in apoptosis in a miniature pig model of laparoscopic HIRI upon hepatectomy. Bama miniature pigs were randomly assigned to sham, I/R and HRS groups. The pigs received 10 mL/kg HRS by portal venous injection 10 min before reperfusion and at 1 d, 2 d, and 3 d after surgery. The results showed that HRS treatment significantly decreased serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bilirubin (TBIL) activity and TUNEL-positive cells. Upon HRS treatment, the expression of P53 and Bax mRNA and protein by RT-qPCR and Western blot was markedly decreased, whereas the expression of bcl-2 mRNA and protein was significantly increased. Moreover, Caspase-3 and Caspase-9 activities were significantly decreased upon treatment with HRS. In conclusion, the results indicate that HRS could alleviate liver injury and improve liver function via inhibiting apoptosis after laparoscopic HIRI and hepatectomy injury in miniature pigs.

Hypoxic preconditioning reduces propofol-induced neuroapoptosis via regulation of Bcl-2 and Bax and downregulation of activated caspase-3 in the hippocampus of neonatal rats

OBJECTIVE

 Evidence has shown that propofol may cause widespread apoptotic neurodegeneration. Hypoxic preconditioning (HPC) was previously demonstrated to provide neuroprotection and brain recovery from either acute or chronic neurodegeneration in several cellular and animal models. Therefore, the present study was designed to investigate the protective effects of hypoxic preconditioning on apoptosis caused by propofol in neonatal rats.

METHODS

Propofol (100 mg/kg) was given to 7-day-old (P7) Sprague Dawley pups. Before the propofol injection, hypoxic preconditioning was administered by subjecting rats to five cycles of 10 min of hypoxia (8% O2) and 10 min of normoxia (21% O2), then 2 h of room air. We detected neuronal structure changes and apoptosis by hematoxylin and eosin (HE) staining and TUNEL assay, respectively. Bcl-2, Bax and cleaved-caspase-3 levels were quantified using Western blotting and immunohistochemistry.

RESULT

 After treatment with propofol, Bcl-2 levels decreased and Bax and cleaved-caspase-3 levels increased. However, our results suggest that hypoxic preconditioning could reverse this change. Conclusion: Our results indicate that pretreatment with hypoxic preconditioning prevents propofol-induced neuroapoptosis by increasing the levels of Bcl-2 and decreasing the levels of Bax and cleaved-caspase-3.

Time-course investigation of blood-brain barrier permeability and tight junction protein changes in a rat model of permanent focal ischemia

Permanent middle cerebral artery occlusion (pMCAO) is an animal model that is widely used to simulate human ischemic stroke. However, the timing of the changes in the expression of tight junction (TJ) proteins and synaptic proteins associated with pMCAO remain incompletely understood. Therefore, to further explore the characteristics and mechanisms of blood-brain barrier (BBB) damage during cerebral ischemic stroke, we used a pMCAO rat model to define dynamic changes in BBB permeability within 120 h after ischemia in order to examine the expression levels of the TJ proteins claudin-5 and occludin and the synaptic proteins synaptophysin (SYP) and postsynaptic density protein 95 (PSD95). In our study, Evans blue content began to increase at 4 h and was highest at 8 and 120 h after ischemia. TTC staining showed that cerebral infarction was observed at 4 h and that the percentage of infarct volume increased with time after ischemia. The expression levels of claudin-5 and occludin began to decline at 1 h and were lowest at 8 and 120 h after ischemia. The expression levels of SYP and PSD95 decreased from 12 to 120 h after ischemia. GFAP, an astrocyte marker, gradually increased in the cortex penumbra over time post-ischemia. Our study helps clarify the characteristics of pMCAO models and provides evidence supporting the translational potential of animal stroke models.

Correlation of expression levels of caspase-3 and Bcl-2 in alveolar lavage fluid in neonatal respiratory distress syndrome and prognosis

This study was designed to investigate the correlation between expression levels of cysteine aspartic protease-3 (caspase-3) and B-cell lymphoma gene-2 (Bcl-2) proteins in alveolar lavage fluid and the prognosis of infants with neonatal respiratory distress syndrome (RDS). A total of 150 infants with neonatal RDS undergoing alveolar lavages were divided into four groups: RDS1 (group A, n=42), RDS2 (group B, n=38), RDS3 (group C, n=38) and RDS4 (group D, n=32) according to their thoracic X-ray film grading. The oxygen uptake score, oxygenation saturation, mean airway pressure and expression levels of caspase-3 and Bcl-2 in alveolar lavage fluid of the infants in the four groups were measured and compared. Our results showed higher grading by thoracic X-rays in patients with increased oxygen uptake score, oxygenation index, mean airway pressure, caspase-3 expression level, hospital stay, complications and death rates in all groups; however, the expression levels of Bcl-2 were decreased in those cases, and the differences had statistical significance among the four groups (P<0.05). Analyses for correlation showed a caspase-3 positive area that was positively correlated with oxygen uptake score, oxygenation index and mean airway pressure (P<0.05); and a Bcl-2 expression level that was negatively correlated with oxygen uptake score, oxygenation index and mean airway pressure (P<0.05). Based on our findings, the severity of neonatal RDS is positively correlated with the concentration of caspase-3 in alveolar lavage fluid, and negatively correlated with the expression level of Bcl-2.

Simvastatin inhibits the apoptosis of hippocampal cells in a mouse model of Alzheimer's disease

Alzheimer's disease is associated with cognitive impairments that affect memory and executive functions. Simvastatin is a cholesterol-lowering statin drug that is used to control levels of cholesterol in the blood, particularly in cases of hypercholesterolemia, and may be used in the treatment of aneurysmal subarachnoid hemorrhage. Previous results have indicated that the apoptosis of hippocampal cells may serve a critical role in the progression of Alzheimer's disease. In the present study, it was determined whether Simvastatin inhibited the apoptosis of hippocampal cells in vitro and in vivo. The therapeutic effects of Simvastatin were evaluated in 24-month-old triple-transgenic Alzheimer's disease (3×Tg-AD) mice, and the efficacy of Simvastatin in attenuating memory and cognitive impairment was investigated. Levels of apoptosis-related gene expression in the hippocampus and hippocampal cells of experimental mice were also detected. In addition, neuron excitability was assessed in the functionally relevant brain regions in the hippocampus. The data indicated that Simvastatin significantly suppressed the apoptosis of hippocampal cells in 3×Tg-AD model mice compared with controls (P<0.01). Furthermore, treatment with Simvastatin improved the dementia status of 3×Tg-AD mice, as determined by a learning task in which mice exhibited significantly reduced attention impairment, impulsivity and compulsivity (P<0.01). In addition, results demonstrated that Simvastatin significantly inhibited hippocampal damage and significantly improved neuronal loss in hippocampal structures classically associated with attentional performance when compared with untreated mice (P<0.01). Thus, Simvastatin prevented cognitive impairment by decreasing hippocampal cell apoptosis and improving learning-memory ability. Simvastatin treatment also increased the expression of anti-apoptotic genes and decreased the expression pro-apoptotic genes (P<0.01), which may have been associated with improved motor attention and cognitive competence in 3×Tg-AD mice. Collectively, these preclinical data indicated that Simvastatin was efficient in attenuating memory lapse and hippocampal cell apoptosis in a 3×Tg-AD mouse model. Thus, Simvastatin may be useful in improving the clinical outcome of patients with Alzheimer's disease.

Treatment with Enriched Environment Reduces Neuronal Apoptosis in the Periinfarct Cortex after Cerebral Ischemia/Reperfusion Injury

Background/Aims: Enriched environment (EE) has been reported to exert neuroprotective effect in animal models of ischemic stroke. However, the underlying mechanism remains unclear. The purpose of this study was to investigate the effect of EE treatment on neuronal apoptosis in the periinfarct cortex after cerebral ischemia/reperfusion (I/R) injury. Methods: The cerebral I/R injury was established by middle cerebral artery occlusion (MCAO). A set of behavioral tests including the modified neurological severity score (mNSS), limb-placing test and foot-fault test were conducted. The infarct volume and the neuronal survival rate were evaluated by Nissl staining. The morphology and ultrastructure of ischemic neurons was examined by transmission electron microscopy. Neuronal apoptosis was assessed by double labeling of TdT-mediated dUTP-biotin nick end labeling (TUNEL) with NeuN. The expressions of apoptosis-related proteins were tested by western blotting and immunohistochemical labeling. Results: EE treatment improved neurological function, reduced infarct volume, increased neuronal survival rate and alleviated the morphological and ultrastructural damage of neurons (especially mitochondria) after I/R injury. EE treatment reduced the neuronal apoptosis, increased B cell lymphoma/leukemia-2 (Bcl-2) protein levels while decreased Bcl-2-associated X protein (Bax), cytochrome c, caspase-3 expressions and Bax/Bcl-2 ratio in the periinfarct cortex after cerebral I/R injury. Conclusion: Our findings suggest that EE treatment inhibits neuronal apoptosis in the periinfarct cortex after focal cerebral I/R injury, which may be one of the possible mechanisms underlying the neuroprotective effects of EE.

The role of erythropoietin in remote renal preconditioning on hippocampus ischemia/reperfusion injury

Remote ischemic preconditioning (RIPC) is an intriguing approach which exposes a remote organ/tissue to a non-lethal transient ischemia/reperfusion (I/R) in order to potentiate the resistance of the desired organ/tissue against the next unwanted I/R. It has been suggested that RIPC exerts its effect through neuronal and hormonal pathways. The underlying mechanisms of RIPC are obscure and should be elucidated. In this study, we induced RIPC in mice using 3 cycles of 5 min ischemia alternating with 5 min reperfusion of the left renal artery. Renal failure was induced in mice by intra-peritoneal (i.p.) injection of 200 mg/kg body weight of gentamicin twice per day for 4 consecutive days. Global hippocampal ischemia reperfusion (I/R) was performed by bilateral carotid artery occlusion for 20 min followed by reperfusion for 72 h. Moreover, the retention trial of passive avoidance test was determined 72 h after global ischemia. Histopathological changes of hippocampus neurons were observed using Nissl staining to detect neuronal loss. Finally, terminal deoxynucleotidyl transferase mediated dUTP nick end-labeling (TUNEL) was performed to assess the status of apoptotic cells in the hippocampus. The results of this study suggest that renal ischemic preconditioning is a good candidate for prevention of I/R-induced hippocampal injury. However, RRPC (remote renal preconditioning) failed to exert a neuroprotective effect in mice with renal failure (RF), indicating the probable role of a humoral factor which is released from kidneys in response to ischemia. In agreement with this hypothesis, treatment of mice with rhEPO (5000 IU/kg intraperitoneal) before induction of RRPC restored the neuroprotective effects of RRPC in RF mice. Accordingly, it is plausible to expect that erythropoietin is released from kidneys to act as a mediator for RRPC-induced neuroprotective effects. Renal ischemic preconditioning prevents I/R-induced hippocampal injury. In contrast, renal failure hampers protective effects of RRPC, while exogenous administration of erythropoietin (EPO) significantly prevents the inhibiting effects of renal failure.

Neuroprotective Effects of Exercise on Brain Edema and Neurological Movement Disorders Following the Cerebral Ischemia and Reperfusion in Rats

Introduction:

Cerebral ischemia and reperfusion causes physiological and biochemical changes in the neuronal cells that will eventually lead to cell damage. Evidence indicates that exercise reduces the ischemia and reperfusion-induced brain damages in animal models of stroke. In the present study, the effect of exercise preconditioning on brain edema and neurological movement disorders following the cerebral ischemia and reperfusion in rats was investigated.

Methods:

Twenty-one adult male wistar rats (weighing 260–300 g) were randomly divided into three groups: sham operated, exercise plus ischemia, and ischemia group (7 rats per group). The rats in exercise group were trained to run on a treadmill 5 days a week for 4 weeks. Transient focal cerebral ischemia and reperfusion were induced by middle cerebral artery occlusion (MCAO) for 60 minutes, followed by reperfusion for 23 hours. After 24 hours ischemia, movement disorders were tested by a special neurological examination. Also, cerebral edema was assessed by determining the brain water content.

Results:

The results showed that pre-ischemic exercise significantly reduced brain edema (P<0.05). In addition, exercise preconditioning decreased the neurological movement disorders caused by brain ischemia and reperfusion (P<0.05).

Conclusion:

Preconditioning by exercise had neuroprotective effects against brain ischemia and reperfusion-induced edema and movement disorders. Thus, it could be considered as a useful strategy for prevention of ischemic injuries, especially in people at risk.

Notch signaling in cerebrovascular diseases (Review)

The Notch signaling pathway is a crucial regulator of numerous fundamental cellular processes. Increasing evidence suggests that Notch signaling is involved in inflammation and oxidative stress, and thus in the progress of cerebrovascular diseases. In addition, Notch signaling in cerebrovascular diseases is associated with apoptosis, angiogenesis and the function of blood-brain barrier. Despite the contradictory results obtained to date as to whether Notch signaling is harmful or beneficial, the regulation of Notch signaling may provide a novel strategy for the treatment of cerebrovascular diseases.

Upregulated Expression of Karyopherin α2 is Involved in Neuronal Apoptosis Following Intracerebral Hemorrhage in Adult Rats

Karyopherin α2 (KPNA2) plays a central role in nucleocytoplasmic transport. It is involved in controlling the flow of genetic information and the modulation of diverse cellular activities. Here we explored the KPNA2's roles during the pathophysiological processes of intracerebral hemorrhage (ICH). An ICH rat model was built and evaluated according to behavioral testing. Using Western blot, immunohistochemistry, and immunofluorescence, significant upregulation of KPNA2 was found in neurons in brain areas surrounding the hematoma following ICH. Increasing KPNA2 level was found to be accompanied by the upregulation of active caspase-3, Bax, and decreased expression of Bcl-2. Besides, KPNA2 co-localized well with active caspase-3 in neurons, indicating its potential role in neuronal apoptosis. What's more, knocking down KPNA2 by RNA-interference in PC12 cells reduced active caspase-3 expression. Thus, KPNA2 may play a role in promoting the brain secondary damage following ICH.

Neuroprotective Effect of Resveratrol on Acute Brain Ischemia Reperfusion Injury by Measuring Annexin V, p53, Bcl-2 Levels in Rats

Background

Cerebral ischemia is as a result of insufficient cerebral blood flow for cerebral metabolic functions. Resveratrol is a natural phytoalexin that can be extracted from grape's skin and had potent role in treating the cerebral ischemia. Apoptosis, a genetically programmed cellular event which occurs after ischemia and leads to biochemical and morphological changes in cells. There are some useful markers for apoptosis like Bcl-2, bax, and p53. The last reports, researchers verify the apoptosis with early markers like Annexin V.

Methods

We preferred in this experimental study a model of global cerebral infarction which was induced by bilateral common carotid artery occlusion method. Rats were randomly divided into 4 groups : sham, ischemia-reperfusion (I/R), I/R plus 20 mg/kg resveratrol and I/R plus 40 mg/kg resveratrol. Statistical analysis was performed using Sigmastat 3.5 ve IBM SPSS Statistics 20. We considered a result significant when p<0.001.

Results

After administration of resveratrol, Bcl-2 and Annexin levels were significantly increased (p<0.001). Depending on the dose of resveratrol, Bcl2 levels increased, p53 levels decreased but Annexin V did not effected. P53 levels were significantly increased in ishemia group, so apoptosis is higher compared to other groups.

Conclusion

In the acute period, Annexin V levels misleading us because the apoptotic cell counts could not reach a certain level. Therefore we should support our results with bcl-2 and p53.