8-hydroxy-2-(di-n-propylamino)tetralin intervenes with neural cell apoptosis following diffuse axonal injury

Previous studies have reported a neuroprotective effect of 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) against traumatic brain injury. In accordance with the Marmarou method, rat models of diffuse axonal injury were established. 8-OH-DPAT was intraperitoneally injected into model rats 8-OH-DPAT treated rats maintained at constant temperature served as normal temperature controls TUNEL results revealed that neural cell swelling, brain tissue necrosis and cell apoptosis occurred around the injured tissue. Moreover, the number of Bax-, Bcl-2- and caspase-3-positive cells increased at 6 hours after diffuse axonal injury, and peaked at 24 hours. However, brain injury was attenuated, the number of apoptotic cells reduced, Bax and caspase-3 expression decreased, and Bcl-2 expression increased at 6, 12, 24, 72 and 168 hours after diffuse axonal injury in normal temperature control and in 8-OH-DPAT-intervention rats. The difference was most significant at 24 hours. All indices in 8-OH-DPAT-intervention rats were better than those in the constant temperature group. These results suggest that 8-OH-DPAT inhibits Bax and caspase-3 expression, increases Bcl-2 expression, and reduces neural cell apoptosis, resulting in neuroprotection against diffuse axonal injury. This effect is associated with a decrease in brain temperature.     

Involvement of the Wnt signaling pathway and cell apoptosis in the rat hippocampus following cerebral ischemia/reperfusion injury

We investigated the role of the Wnt signaling pathway in cerebral ischemia/reperfusion injury by examining β-catenin and glycogen synthase kinase-3β protein expression in the rat hippocampal CA1 region following acute cerebral ischemia/reperfusion. Our results demonstrate that cell apoptosis increases in the CA1 region following ischemia/reperfusion. In addition, β-catenin and glycogen synthase kinase-3β protein expression gradually increases, peaking at 48 hours following reperfusion. Dickkopf-1 administration, after cerebral ischemia/reperfusion injury, results in decreased cell apoptosis, and β-catenin and glycogen synthase kinase-3β expression, in the CA1 region. This suggests that β-catenin and glycogen synthase kinase-3β, both components of the Wnt signaling pathway, participate in cell apoptosis following cerebral ischemia/reperfusion injury.     

Hippocampal ultrastructural changes and apoptotic cell death in rats following endurance training and acute exhaustive exercise

BACKGROUND： Exhaustive exercise can lead to apoptosis of skeletal muscle cells and myocardial cells as a result of pathological changes in the corresponding cellular ultrastructure. It is hypothesized that such changes could also occur in neurons. OBJECTIVE： To observe brain cell apoptosis and ultrastructural changes in hippocampal neurons in rats following endurance training and acute exhaustive exercise. DESIGN, TIME AND SETTING： A randomized, controlled, morphological analysis was performed at the Medical Laboratory Center of Zhengzhou University between July and November 2007. MATERIALS： Forty male, 8-week-old, Sprague Dawley rats were included in this study. METHODS： Endurance training consisted of treadmill running once a day, 6 days a week, for 4. weeks. For acute exhaustive exercise, graded treadmill running was conducted. Rats were exposed to exercise at an increasing speed （10 m/min, increasing to 20 and 36 m/min for moderate- and high-intensity exhaustive exercise, respectively, and then was continued until exhaustion）. A total of 40 rats were evenly distributed into the following 4. groups： Group A rats were not exercised; Group B rats were not trained but sacrificed 24 hours after acute exhaustive treadmill running exercise; Group C-rats were subjected to endurance training and sacrificed immediately after acute exhaustive treadmill running exercise; Group D rats were subjected to endurance training and sacrificed 24 hours after acute exhaustive treadmill running exercise. MAIN OUTCOME MEASURES： Apoptotic cell death was detected by the TUNEL method and hippocampal neuronal ultrastructural change was observed through using transmission electron microscopy. RESULTS： All 40 rats were included in the final analysis. Subsequent to exhaustive exercise, rat cerebral cortex and hippocampal neurons appeared contracted and degenerated. In addition, high amount of lipofuscin was visible in the hippocampal region, Necrotic neurons encased by glial cells appeared in the cerebral cortex and hip     

Effects of genistein on neuronal apoptosis, and expression of Bcl-2 and Bax proteins in the hippocampus of ovariectomized rats

Genistein is one of several isoflavones that has a structure similar to 17β-estradiol, has a strong antioxidant effect, and a high affinity to estrogen receptors. At 15 weeks after ovariectomy, the expression of Bcl-2 in the hippocampus of rats decreased and Bax expression increased, with an obvious upregulation of apoptosis. However, intraperitoneal injection of genistein or 17β-estradiol for 15 consecutive weeks from the second day after operation upregulated Bcl-2 protein expression downregulated Bax protein expression, and attenuated hippocampal neuron apoptosis. Our experimental findings indicate that long-term intervention with genistein can lead to a decrease in apoptosis in hippocampal neurons following ovariectomy, upregulate the expression of Bcl-2, and downregulate the expression of Bax. In addition, genistein and 17β-estradiol play equal anti-apoptotic and neuroprotective roles.     

Expression of netrin-1 and its receptors, deleted in colorectal cancer and uncoordinated locomotion-5 homolog B, in rat brain following focal cerebral ischemia reperfusion injury

Netrin-1 is currently one of the most highly studied axon guidance factors. Netrin-1 is widely expressed in the embryonic central nervous system, and together with the deleted in colorectal cancer and uncoordinated locomotion-5 homolog B receptors, netrin-1 plays a guiding role in the construction of neural conduction pathways and the directional migration of neuronal cells. In this study, we established a rat middle cerebral artery ischemia reperfusion model using the intraluminal thread technique. Immunofluorescence microscopy showed that the expression of netrin-1 and deleted in colorectal cancer in the ischemic penumbra was upregulated at 1 day after reperfusion, reached a peak at 14 days, and decreased at 21 days. There was no obvious change in the expression of uncoordinated locomotion-5 homolog B during this time period. Double immunofluorescence labeling revealed that netrin-1 was expressed in neuronal cells and around small vessels, but not in astrocytes and microglia, while deleted in colorectal cancer was localized in the cell membranes and protrusions of neurons and astrocytes. Our experimental findings indicate that netrin-1 may be involved in post-ischemic repair and neuronal protection via deleted in colorectal cancer receptors.     

Isoflurane-induced neuronal apoptosis in developing hippocampal neurons

We hypothesized that the P2X7 receptor may be the target of isoflurane, so we investigated the roles of the P2X7 receptor and inositol triphosphate receptor in calcium overload and neuronal apoptosis induced by isoflurane in cultured embryonic rat hippocampal neurons. Results showed that isoflurane induced widespread neuronal apoptosis and significantly increased cytoplasmic Ca 2+ . Blockade of P2X7 receptors or removal of extracellular Ca 2+ combined with blockade of inositol triphosphate receptors completely inhibited apoptosis or increase in cytoplasmic Ca 2+ . Removal of extracellular Ca 2+ or blockade of inositol triphosphate receptor alone could partly inhibit these effects of isoflurane. Isoflurane could directly activate P2X7-gated channels and induce inward currents, but did not affect the expression of P2X7 receptor protein in neurons. These findings indicate that the mechanism by which isoflurane induced neuronal apoptosis in rat developing brain was mediated by intracellular calcium overload, which was caused by P2X7 receptor mediated calcium influx and inositol triphosphate receptor mediated calcium release.     

The calmodulin-dependent protein kinase II inhibitor KN-93 protects rat cerebral cortical neurons from N-methyl-D-aspartic acid-induced injury

In this study, primary cultured cerebral cortical neurons of Sprague-Dawley neonatal rats were treated with 0.25, 0.5, and 1.0 μM calmodulin-dependent protein kinase II inhibitor KN-93 after 50 μM N-methyl-D-aspartic acid-induced injury. Results showed that, compared with N-methyl-D-aspartic acid-induced injury neurons, the activity of cells markedly increased, apoptosis was significantly reduced, leakage of lactate dehydrogenase decreased, and intracellular Ca(2+) concentrations in neurons reduced after KN-93 treatment. The expression of caspase-3, phosphorylated calmodulin-dependent protein kinase II and total calmodulin-dependent protein kinase II protein decreased after KN-93 treatment. And the effect was apparent at a dose of 1.0 μM KN-93. Experimental findings suggest that KN-93 can induce a dose-dependent neuroprotective effect, and that the underlying mechanism may be related to the down-regulation of caspase-3 and calmodulin-dependent protein kinase II expression.     

Ischemic preconditioning reduces ischemic brain injury by suppressing nuclear factor kappa B expression and neuronal apoptosis

Ischemic stroke induces a series of complex pathophysiological events including blood-brain barrier disruption, inflammatory response and neuronal apoptosis. Previous studies demonstrate that ischemic preconditioning attenuates ischemic brain damage via inhibiting blood-brain barrier disruption and the inflammatory response. Rats underwent transient (15 minutes) occlusion of the bilateral common carotid artery with 48 hours of reperfusion, and were subjected to permanent middle cerebral artery occlusion. This study explored whether ischemic preconditioning could reduce ischemic brain injury and relevant molecular mechanisms by inhibiting neuronal apoptosis. Results found that at 72 hours following cerebral ischemia, myeloperoxidase activity was enhanced, malondialdehyde levels increased, and neurological function was obviously damaged. Simultaneously, neuronal apoptosis increased, and nuclear factor-κB and cleaved caspase-3 expression was significantly increased in ischemic brain tissues. Ischemic preconditioning reduced the cerebral ischemia-induced inflammatory response, lipid peroxidation, and neurological function injury. In addition, ischemic preconditioning decreased nuclear factor-κB p65 and cleaved caspase-3 expression. These results suggested that ischemic preconditioning plays a protective effect against ischemic brain injury by suppressing the inflammatory response, reducing lipid peroxidation, and neuronal apoptosis via inhibition of nuclear factor-κB and cleaved caspase-3 expression.     

脑出血患者血肿周围组织神经元凋亡与Bcl-2、Bax蛋白表达关系的研究

目的探讨脑出血(ICH)患者血肿周围组织神经元凋亡与凋亡相关基因Bcl2、Bax蛋白表达的关系。方法采用缺口末端标记法、免疫组化法分别检测ICH患者血肿周围组织神经元凋亡率和Bcl2、Bax表达水平,分析神经元凋亡率与Bcl2、Bax表达及Bax/Bcl2值的关系;出血量与Bcl2、Bax表达及Bax/Bcl2值的关系,以及神经元凋亡率与出血量、病程、神经功能缺损程度评分(NDS)的关系。结果ICH患者血肿周围组织神经元凋亡率及Bcl2、Bax表达明显高于正常对照组(均P<0.01);血肿周围组织神经元凋亡率与Bcl2表达呈负相关(r=-0.682,P<0.01),与Bax、Bax/Bcl2值表达呈正相关(r=0.592、0.740,均P<0.01)。出血量与血肿周围组织Bcl2表达呈负相关(r=-0.677,P<0.01),与Bax表达及Bax/Bcl2值呈正相关(r=0.654、0.751,均P<0.01)。细胞凋亡率与出血量及NDS呈正相关(r=0.829、0.897,均P<0.01),与病程不相关。结论细胞凋亡机制参与了ICH后继发性神经元损伤;Bcl2、Bax蛋白及Bax/Bcl2值对凋亡具有调控作用。     

Low-intensity treadmill exercise and/or bright light promote neurogenesis in adult rat brain

The hippocampus is a brain region responsible for learning and memory functions. The purpose of this study was to investigate the effects of low-intensity exercise and bright light exposure on neurogenesis and brain-derived neurotrophic factor expression in adult rat hippocampus. Male Sprague-Dawley rats were randomly assigned to control, exercise, light, or exercise + light groups (n = 9 per group). The rats in the exercise group were subjected to treadmill exercise (5 days per week, 30 minutes per day, over a 4-week period), the light group rats were irradiated (5 days per week, 30 minutes per day, 10 000 lx, over a 4-week period), the exercise + light group rats were subjected to treadmill exercise in combination with bright light exposure, and the control group rats remained sedentary over a 4-week period. Compared with the control group, there was a significant increase in neurogenesis in the hippocampal dentate gyrus of rats in the exercise, light, and exercise + light groups. Moreover, the expression level of brain-derived neurotrophic factor in the rat hippocampal dentate gyrus was significantly higher in the exercise group and light group than that in the control group. Interestingly, there was no significant difference in brain-derived neurotrophic factor expression between the control group and exercise + light group. These results indicate that low-intensity treadmill exercise (first 5 minutes at a speed of 2 m/min, second 5 minutes at a speed of 5 m/min, and the last 20 minutes at a speed of 8 m/min) or bright-light exposure therapy induces positive biochemical changes in the brain. In view of these findings, we propose that moderate exercise or exposure to sunlight during childhood can be beneficial for neural development.     

Optimal time for subarachnoid transplantation of neural progenitor cells in the treatment of contusive spinal cord injury

This study aimed to identify the optimal neural progenitor cell transplantation time for spinal cord injury in rats via the subarachnoid space. Cultured neural progenitor cells from 14-day embryonic rats, constitutively expressing enhanced green fluorescence protein, or media alone, were injected into the subarachnoid space of adult rats at 1 hour (acute stage), 7 days (subacute stage) and 28 days (chronic stage) after contusive spinal cord injury. Results showed that grafted neural progenitor cells migrated and aggregated around the blood vessels of the injured region, and infiltrated the spinal cord parenchyma along the tissue spaces in the acute stage transplantation group. However, this was not observed in subacute and chronic stage transplantation groups. O4- and glial fibrillary acidic protein-positive cells, representing oligodendrocytes and astrocytes respectively, were detected in the core of the grafted cluster attached to the cauda equina pia surface in the chronic stage transplantation group 8 weeks after transplantation. Both acute and subacute stage transplantation groups were negative for O4 and glial fibrillary acidic protein cells. Basso, Beattie and Bresnahan scale score comparisons indicated that rat hind limb locomotor activity showed better recovery after acute stage transplantation than after subacute and chronic transplantation. Our experimental findings suggest that the subarachnoid route could be useful for transplantation of neural progenitor cells at the acute stage of spinal cord injury. Although grafted cells survived only for a short time and did not differentiate into astrocytes or neurons, they were able to reach the parenchyma of the injured spinal cord and improve neurological function in rats. Transplantation efficacy was enhanced at the acute stage in comparison with subacute and chronic stages.     

Treadmill exercise attenuates 3,4‐methylenedioxymethamphetamine‐induced memory impairment through a decrease apoptosis in male rat hippocampus

3,4‐methylenedioxymethamphetamine (MDMA) leads to apoptosis in the hippocampus with consequent induction of learning and memory impairment. In this study, we have investigated the effects of treadmill exercise on memory in relation to apoptosis and oxidative stress in the hippocampi of MDMA‐treated rats. Male Wistar rats received multiple intraperitoneal (IP) injections of MDMA (10 mg/kg) and exercised for one month on a treadmill (simultaneously or asynchronously with MDMA). We assessed memory function with the Morris water maze (MWM) test. Lipid peroxidation (LPO) and expression of caspase 3, Bax, and Bcl‐2 were examined by the thiobarbituric acid assay (TBA) and western blot, respectively. Our results showed that asynchronous treadmill exercise could significantly improve MDMA‐induced memory impairment in the MWM test. Caspase 3 expression decreased in the exercise group compared to the MDMA group. Although MDMA treatment caused an increase in the Bax/Bcl‐2 ratio, the treadmill exercise reduced this ratio. Simultaneous exercise caused a reduction in lipid peroxidation in the hippocampus. This data suggests that treadmill exercise can be a useful strategy for treating memory impairment in persons with neurodegenerative disease and stimulant drug users. © 2017 Wiley Periodicals, Inc.     

Carbenoxolone pretreatment and treatment of posttraumatic epilepsy

Gap junction blocking agents can inhibit spontaneous discharge frequency in cells. We established a rat model of posttraumatic epilepsy induced using ferric ions. Rats were intraperitoneally injected with carbenoxolone, 20 mg/kg, prior to and 30 minutes after model establishment, once a day for 14 consecutive days. Immunohistochemistry showed glial cell proliferation around a cortical focus and significantly increased connexin expression in posttraumatic epilepsy. However, carbenoxolone pretreatment or treatment significantly reduced connexin expression in the cortex, inhibited glial fibrillary acidic protein expression and ameliorated seizure degree in rats. These findings indicate that large amounts of glial cell proliferation and abnormal gap junction generation play a role in posttraumatic epilepsy, and that carbenoxolone may prevent and treat this disease.     

Endogenous adult neurogenesis and cognitive function recovery following traumatic brain injury in the rat hippocampus

BACKGROUND:Endogenous neural progenitor cells play a beneficial role for cognitive recovery following traumatic brain injury.However,there are few classification-control studies aimed at varying graded brain trauma.OBJECTIVE:To observe the effects of adult endogenous neurogenesis on cognitive function repair and regeneration of neural progenitor cells following varying graded traumatic hippocampal injury to determine the significance of endogenous neurogenesis in the repair of brain injury.DESIGN,TIME AND SETTING:A randomized,controlled,animal experiment was performed at the Key Laboratory of Injuries,Variations and Regeneration of Nervous System,Tianjin Medical University General Hospital,from February to October 2009.MATERIALS:Mouse anti-rat 5-bromodeoxyuridine (BrdU) and neuronal nuclei (NeuN) monoclonal antibodies were purchased from Millipore Corporation,USA.METHODS:A total of 45 Wistar rats were randomly assigned to three groups.Mild and severe injury groups were respectively subjected to (182 ± 2) kPa and (284 ± 4) kPa lateral fluid percussion to establish models of brain injury,and the control group was subjected to surgery with no lateral fluid percussion.MAIN OUTCOME MEASURES:Cognitive function was estimated using the Morris water maze.Proliferation,survival,and differentiation of newly generated cells in the injured hippocampus were observed through the use of immunofluorescent staining.RESULTS:At 7 days post-injury,the number of BrdU+ cells in the hippocampal dentate gyrus significantly increased in the mild and severe injury groups compared with the control group (P<0.01).At 61 days post-injury,the number of BrdU7NeuN+ cells in the hippocampal dentate gyrus was significantly greater in the mild injury group compared with the severe injury and control groups (P< 0.01).In addition,the control group exhibited the greatest proportion of surviving cells that differentiated into mature neurons compared with the injury groups (P< 0.01).Moreover,at 61 days post-injury,cognitive function in rats with mild injury recovered to normal levels,whereas the severe injury group exhibited cognitive deficits (P< 0.01).CONCLUSION:Traumatic brain injury may be a stimulation factor for proliferation of neural progenitor cells in the adult hippocampus but severe brain trauma does not lead to an increased number of newly generated cells.Endogenous adult neurogenesis repairs neurological functions to an extent.However,recovery of neurological function remains limited following severe traumatic brain injury.     

Effect of compound preparation Tongqiao Jiannao capsules on neural cell apoptosis and Bcl-2 and Bax protein levels in a rat model of brain ischemia/reperfusion injury

BACKGROUND:Pharmacological studies have demonstrated that compound preparation Tongqiao Jiannao capsules composed of Zexie, Baizhu, Honghua, Danshen, and Shexiang can supplement qi, activate blood circulation, relieve blood stasis, induce resuscitation for alleviating pain, relieve pain, and dilate blood vessels. OBJECTIVE: To observe the effects of Tongqiao Jiannao capsules on the levels of the anti-apoptotic protein Bcl-2 and the proapoptotic protein Bax, and verify the mechanism of action. DESIGN, TIME A...     

Effect of compound preparation Tongqiao Jiannao capsules on neural cell apoptosis and Bcl-2 and Bax protein levels in a rat model of brain ischemia/reperfusion injury★

BACKGROUND：Pharmacological studies have demonstrated that compound preparation Tongqiao Jiannao capsules composed of Zexie, Baizhu, Honghua, Danshen, and Shexiang can supplement qi, activate blood circulation, relieve blood stasis, induce resuscitation for alleviating pain, relieve pain, and dilate blood vessels. OBJECTIVE： To observe the effects of Tongqiao Jiannao capsules on the levels of the anti-apoptotic protein Bcl-2 and the proapoptotic protein Bax, and verify the mechanism of action. DESIGN, TIME AND SETTING： Randomized, controlled animal experiment, performed in the Laboratory of Biochemistry and Molecular Biology, Shanxi Medical University between June 2001 and December 2002. MATERIALS： The right middle cerebral arteries of 24 healthy adult Sprague Dawley rats were occluded by the suture method. The primary Chinese herbal medicinal ingredients of Tongqiao Jiannao capsules are Zexie, Baizhu, Honghua, Danshen, and Shexiang, which were purchased from Shanxi Provincial Medicinal Material Company, China, and prepared into condensed granules in the Room for Chinese Herbal Medicine Preparation, Second Hospital, Shanxi Medical University. Bcl-2 and Bax immunohistochemical staining kits, a 3,3-diaminobenzidine（DAB） kit, and an in situ apoptosis detection kit were purchased from Wuhan Boster Bioengineering Co., Ltd., China. METHODS： Twenty-four rats were randomly and evenly divided into three groups： （1） sham-operated rats in which sutures were inserted and immediately pulled out; （2） Tongqiao Jiannao capsule-treated rats that were intragastrically administered 6.5 g/kg/d Tongqiao Jiannao capsule preparation for seven successive days prior to middle cerebral artery occlusion （MCAO）; and （3） MCAO rats without any other treatments. MAIN OUTCOME MEASURES： The levels of neural cell apoptosis and Bcl-2 and Bax proteins at 24 hours post-surgery. RESULTS： In the MCAO group, the numbers of apoptotic cells and Bax-positive cells were significantly increased, while the numbers of Bcl-2-     

Chloride channel blocker 4,4-diisothiocyanatostilbene-2,2’-disulfonic acid inhibits nitric oxide-induced apoptosis in cultured rat hippocampal neurons

Apoptosis in cultured rat hippocampal neurons was induced using the nitric oxide donor 3-morpholinosydnonimine, and cells were treated with the chloride channel blocker, 4,4-diisothiocyanatostilbene-2,2’-disulfonic acid. Results showed that the survival rate of neurons was significantly increased after treatment with 4,4-diisothiocyanatostilbene-2,2’-disulfonic acid, and the rate of apoptosis decreased. In addition, the expression of the apoptosis-related proteins poly(adenosine diphosphate-ribose)polymerase-1 and apoptosis-inducing factor were significantly reduced. Our experimental findings indicate that the chloride channel blocker 4,4- diisothiocyanatostilbene-2,2’-disulfonic acid can antagonize apoptotic cell death of hippocampal neurons by inhibiting the expression of the apoptosis-related proteins poly(adenosine diphosphate-ribose)polymerase-1 and apoptosis-inducing factor.     

Expression of synaptosomal-associated protein-25 in the rat brain after subarachnoid hemorrhage

Synaptosomal-associated protein-25 is an important factor for synaptic functions and cognition. In this study, subarachnoid hemorrhage models with spatial learning disorder were established through a b...