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Cerebral palsy (CP) is the most common neuromuscular disorder in children with no effective therapeutic methods. To examine CP, a large variety of methods and animal models was developed, the most popular are the hypoxic-ischemic (HI) injury and/or LPS injection in mice. In the presented work, HI and LPS were applied on the postnatal day 9 to humanized immunodeficiency mouse pups, thereupon 3 behavioral tests were performed in 8 weeks later. Both HI and LPS caused significant behavioral deficits assessed in the Rotarod test. In gait dynamics and open-field tests, HI and LPS caused significant behavioral deficits reported by some parameters, and the effect of HI was more severe. Additionally, HI and LPS produced the different effects on gait dynamics of the fore and hind paws. Thus, both HI and LPS induced the behavioral disorders in mice, but HI was more suitable for the development of humanized immunodeficiency mouse model of CP. [ABSTRACT FROM AUTHOR]

Hypoxia-inducible factor 1α (HIF1α) is a key regulator of oxygen homeostasis, and its target genes mediate adaptive, protective, and pathological processes. The role of HIF1α in neuronal survival is controversial and the brain maturation stage is important in determining its function in brain ischemia or hypoxia-ischemia (HI). In this study, we used neuron-specific HIF1α knockout mice at postnatal day 9 (P9), and immature cortical neurons (days 7-8 in vitro) treated with the HIF1α inhibitor 2-methoxyestradiol (2ME2) or stabilizer dimethyloxalylglycine (DMOG), to examine the function of neuronal HIF1α in neonatal HI in vivo (Vannucci model) and in vitro (oxygen glucose deprivation, OGD). Inhibition of HIF1α with 2ME2 in primary neurons or deletion of neuronal HIF1α in P9 mice increased both necrotic and apoptotic cell death following HI, as evaluated by the protein levels of 145/150-kDa and 120-kDa spectrin breakdown products 24 h after HI. DMOG attenuated neuronal death right after OGD. Acute pharmacological manipulation of HIF1α synchronously regulated the expression of its targets, vascular endothelial growth factor (VEGF) and erythropoietin (Epo), in the same manner. The in vivo findings agree with our previous data using the same HIF1α-deficient mice at an earlier age. This study confirms the role of neuronal HIF1α signaling in the endogenous protective responses following HI in the developing brain.

Introduction: Nerve growth factor (NGF) is a pleiotropic molecule acting on different cell types in physiological and pathological conditions. However, the effect of NGF on the survival, differentiation and maturation of oligodendrocyte precursor cells (OPCs) and oligodendrocytes (OLs), the cells responsible for myelin formation, turnover, and repair in the central nervous system (CNS), is still poorly understood and heavily debated. Methods: Here we used mixed neural stem cell (NSC)-derived OPC/astrocyte cultures to clarify the role of NGF throughout the entire process of OL differentiation and investigate its putative role in OPC protection under pathological conditions. Results: We first showed that the gene expression of all the neurotrophin receptors (TrkA, TrkB, TrkC, and p75NTR) dynamically changes during the differentiation. However, only TrkA and p75NTR expression depends on T3-differentiation induction, as Ngf gene expression induction and protein secretion in the culture medium. Moreover, in the mixed culture, astrocytes are the main producer of NGF protein, and OPCs express both TrkA and p75NTR. NGF treatment increases the percentage of mature OLs, while NGF blocking by neutralizing antibody and TRKA antagonist impairs OPC differentiation. Moreover, both NGF exposure and astrocyte-conditioned medium protect OPCs exposed to oxygenglucose deprivation (OGD) from cell death and NGF induces an increase of AKT/pAKT levels in OPCs nuclei by TRKA activation. Discussion: This study demonstrated that NGF is implicated in OPC differentiation, maturation, and protection in the presence of metabolic challenges, also suggesting implications for the treatment of demyelinating lesions and diseases. [ABSTRACT FROM AUTHOR]

Human umbilical cord mesenchymal stem cells (hUCMSC) have shown promising potential in ameliorating brain injury, but the mechanism is unclear. We explore the role of NogoA/NgR/Rho pathway in mediating hUCMSC to improve neurobehavioral status and alleviate brain injury in hypoxia/ischemia-induced CP (cerebral palsy) rat model in order to promote the clinical application of stem cell therapy in CP. The injury model of HT22 cells was established after 3 h hypoxia, and then co-cultured with hUCMSC. The rat model of CP was established by ligation of the left common carotid artery for 2.5 h. Subsequently, hUCMSC was administered via the tail vein once a week for a total of four times. The neurobehavioral status of CP rats was determined by behavioral experiment, and the pathological brain injury was determined by pathological staining method. The mRNA and protein expressions of NogoA, NgR, RhoA, Rac1, and CDC42 in brain tissues of rats in all groups and cell groups were detected by real-time quantitative polymerase chain reaction (RT-qPCR), Western blot, and immunofluorescence. The CP rats exhibited obvious motor function abnormalities and pathological damage. Compared with the control group, hUCMSC transplantation could significantly improve the neurobehavioral situation and attenuate brain pathological injury in CP rats. The relative expression of NogoA, NgR, RhoA mRNA, and protein in brain tissues of rats in the CP group was significantly higher than the rats in the sham and CP+hUCMSC group. The relative expression of Rac1, CDC42 mRNA, and protein in brain tissues of rats in the CP group was significantly lower than the rats in the sham and CP+hUCMSC group. The animal experiment results were consistent with the experimental trend of hypoxic injury of HT22 cells. This study confirmed that hUCMSC can efficiently improve neurobehavioral status and alleviate brain injury in hypoxia/ischemia-induced CP rat model and HT22 cell model through downregulating the NogoA/NgR/Rho pathway. [ABSTRACT FROM AUTHOR]

IntroductionNerve growth factor (NGF) is a pleiotropic molecule acting on different cell types in physiological and pathological conditions. However, the effect of NGF on the survival, differentiation and maturation of oligodendrocyte precursor cells (OPCs) and oligodendrocytes (OLs), the cells responsible for myelin formation, turnover, and repair in the central nervous system (CNS), is still poorly understood and heavily debated.MethodsHere we used mixed neural stem cell (NSC)-derived OPC/astrocyte cultures to clarify the role of NGF throughout the entire process of OL differentiation and investigate its putative role in OPC protection under pathological conditions.ResultsWe first showed that the gene expression of all the neurotrophin receptors (TrkA, TrkB, TrkC, and p75NTR) dynamically changes during the differentiation. However, only TrkA and p75NTR expression depends on T3-differentiation induction, as Ngf gene expression induction and protein secretion in the culture medium. Moreover, in the mixed culture, astrocytes are the main producer of NGF protein, and OPCs express both TrkA and p75NTR. NGF treatment increases the percentage of mature OLs, while NGF blocking by neutralizing antibody and TRKA antagonist impairs OPC differentiation. Moreover, both NGF exposure and astrocyte-conditioned medium protect OPCs exposed to oxygenglucose deprivation (OGD) from cell death and NGF induces an increase of AKT/pAKT levels in OPCs nuclei by TRKA activation.DiscussionThis study demonstrated that NGF is implicated in OPC differentiation, maturation, and protection in the presence of metabolic challenges, also suggesting implications for the treatment of demyelinating lesions and diseases.

The N-methyl-d-aspartate-type glutamate receptor (NMDAR)-associated multiprotein complexes are indispensable for synaptic plasticity and cognitive functions. While purification and proteomic analyses of these signaling complexes have been performed in adult rodent and human brain, much less is known about the protein composition of NMDAR complexes in the developing brain and their modifications by neonatal hypoxic-ischemic (HI) brain injury. In this study, the postsynaptic density proteins were prepared from postnatal day 9 naïve, sham-operated and HI-injured mouse cortex. The GluN2B-containing NMDAR complexes were purified by immunoprecipitation with a mouse GluN2B antibody and subjected to mass spectrometry analysis for determination of the GluN2B binding partners. A total of 71 proteins of different functional categories were identified from the naïve animals as native GluN2B-interacting partners in the developing mouse brain. Neonatal HI reshaped the postsynaptic GluN2B interactome by recruiting new proteins, including multiple kinases, into the complexes; and modifying the existing associations within 1h of reperfusion. The early responses of postsynaptic NMDAR complexes and their related signaling networks may contribute to molecular processes leading to cell survival or death, brain damage and/or neurological disorders in term infants with neonatal encephalopathy.

Hypoxia-inducible factor 1α (HIF1α) is a key regulator of oxygen homeostasis, and its target genes mediate adaptive, protective, and pathological processes. The role of HIF1α in neuronal survival is controversial and the brain maturation stage is important in determining its function in brain ischemia or hypoxia-ischemia (HI). In this study, we used neuron-specific HIF1α knockout mice at postnatal day 9 (P9), and immature cortical neurons (days 7-8 in vitro) treated with the HIF1α inhibitor 2-methoxyestradiol (2ME2) or stabilizer dimethyloxalylglycine (DMOG), to examine the function of neuronal HIF1α in neonatal HI in vivo (Vannucci model) and in vitro (oxygen glucose deprivation, OGD). Inhibition of HIF1α with 2ME2 in primary neurons or deletion of neuronal HIF1α in P9 mice increased both necrotic and apoptotic cell death following HI, as evaluated by the protein levels of 145/150-kDa and 120-kDa spectrin breakdown products 24 h after HI. DMOG attenuated neuronal death right after OGD. Acute pharmacological manipulation of HIF1α synchronously regulated the expression of its targets, vascular endothelial growth factor (VEGF) and erythropoietin (Epo), in the same manner. The in vivo findings agree with our previous data using the same HIF1α-deficient mice at an earlier age. This study confirms the role of neuronal HIF1α signaling in the endogenous protective responses following HI in the developing brain.

Scutellarin (Scu), a flavonoid from herbal Erigeron breviscapus (Vaniot) Hand-Mazz, exerts neuroprotective effects against cerebral ischemia. However, whether the effects of Scu are related to mitochondrial protection needs further investigation. In this study, we aimed to clarify the mechanisms of Scu against HT22 cells injury caused by oxygen-glucose deprivation and reperfusion (OGD/R). Our results proved that Scu significantly reduced the overload of intracellular reactive oxygen species (cellar ROS) and mitochondria reactive oxygen species (mito-ROS), ameliorating oxidative stress damage. TUNEL positive rate, Caspase-3 activity, and Cytochrome c (Cyto-c) expression remarkably decreased following Scu treatment. Meanwhile, Scu could maintain mitochondrial morphology and reverse ultrastructure changes. And mitochondrial membrane potential (MMP), oxygen consumption rate (OCR), adenosine triphosphate (ATP) production and Na+/K+-ATPase activity were obviously promoted. Additionally, Scu was found to stimulate mitophagy level by increasing the expression of LC3, Beclin1, PINK1 and Parkin proteins, as well as promoting the degradation of p62. More importantly, the regulatory effects of Scu on mito-ROS, MMP, ATP, Na+/K+-ATPase, cell viability and lactate dehydrogenase (LDH) were markedly limited by Mdivi-1 (a mitophagy inhibitor). Of note, the inhibitor also reversed Scu-mediated apoptosis suppression, evidenced by the diminished apoptosis rate, the down-regulated expression activities of Cyto-c, Bax and cleaved Caspase-3, as well as the elevated level of Bcl-2 protein. Collectively, Scu could improve mitochondrial dysfunction and inhibit apoptosis by stimulating mitophagy, thereby attenuating OGD/R-induced HT22 cells injury. [Display omitted] • Scu displays neuroprotection by maintaining mitochondrial integrity and improving mitochondrial energy metabolism. • Scu can alleviate mitochondrial dysfunction and apoptosis through mitophagy induction. • Scu is expected to be a promising agent for mitochondrial protection against cerebral ischemia. [ABSTRACT FROM AUTHOR]

Proteomics of the synapses and postsynaptic densities (PSDs) have provided a deep understanding of protein composition and signal networks in the adult brain, which underlie neuronal plasticity and neurodegenerative or psychiatric disorders. However, there is a paucity of knowledge about the architecture and organization of PSDs in the immature brain, and how it is modified by brain injury in an early developing stage. Mass spectrometry (MS)-based proteomic analysis was performed on PSDs prepared from cortices of postnatal day 9 naïve mice or pups which had suffered hypoxic-ischemic (HI) brain injury. 512 proteins of different functional groups were identified from PSDs collected 1 h after HI injury, among which 60 have not been reported previously. Seven newly identified proteins involved in neural development were highlighted. HI injury increased the yield of PSDs at early time points upon reperfusion, and multiple proteins were recruited into PSDs following the insult. Quantitative analysis was performed using spectral counting, and proteins whose relative expression was more than 50% up- or downregulated compared to the sham animals 1 h after HI insult were reported. Validation with Western blotting demonstrated changes in expression and phosphorylation of the N-methyl-D-aspartate receptor, activation of a series of postsynaptic protein kinases and dysregulation of scaffold and adaptor proteins in response to neonatal HI insult. This work, along with other recent studies of synaptic protein profiling in the immature brain, builds a foundation for future investigation on the molecular mechanisms underlying developing plasticity. Furthermore, it provides insights into the biochemical changes of PSDs following early brain hypoxia-ischemia, which is helpful for understanding not only the injury mechanisms, but also the process of repair or replenishment of neuronal circuits during recovery from brain damage.

Abstract Background Neonatal encephalopathy often leads to lifelong disabilities with limited treatments currently available. The brain vasculature is an important factor in many neonatal neurological disorders but there is a lack of diagnostic tools to evaluate the brain vascular dysfunction of neonates in the clinical setting. Measurement of blood–brain barrier tight-junction (TJ) proteins have shown promise as biomarkers for brain injury in the adult. Here we tested the biomarker potential of tight-junctions in the context of neonatal brain injury. Methods The levels of TJ-proteins (occluding, claudin-5, and zonula occludens protein 1) in both blood plasma and cerebrospinal fluid (CSF) as well as blood–brain barrier function via 14C-sucrose (342 Da) and Evans blue extravasation were measured in a hypoxia/ischemia brain-injury model in neonatal rats. Results Time-dependent changes of occludin and claudin-5 levels could be measured in blood and CSF after hypoxia/ischemia with males generally having higher levels than females. The levels of claudin-5 in CSF correlated with the severity of the brain injury at 24 h post- hypoxia/ischemia. Simultaneously, we detected early increase in blood–brain barrier-permeability at 6 and 24 h after hypoxia/ischemia. Conclusions Levels of circulating claudin-5 and occludin are increased after hypoxic/ischemic brain injuries and blood–brain barrier-impairment and have promise as early biomarkers for cerebral vascular dysfunction and as a tool for risk assessment of neonatal brain injuries.

Experimental models for chronic skin lesions are excision and pressure ulcer, defined as "open" and "closed" lesions, respectively, only the latter characterized by tissue hypoxia. Moreover, systemic diseases, such as diabetes mellitus, affect wound repair. Thus, models for testing new therapies should be carefully selected according to the expected targets. In this study, we present an extensive and comparative histological, immunohistochemical, and molecular characterization of these two lesions in diabetic (db/db) and non-diabetic (C57BL/6 J) mice. In db/db mice, we found significant reduction in PGP9.5-IR innervation, reduction of capillary network, and reduced expression of NGF receptors. We found an increase in VEGF receptor Kdr expression, and the PI3K-Akt signaling pathway at the core of the altered molecular network. Db/db mice with pressure ulcers showed an impairment in the molecular regulation of hypoxia-related genes (Hif1a, Flt1, and Kdr), while extracellular matrix encoding genes (Itgb3, Timp1, Fn1, Col4a1) were upregulated by hyperglycemia and lesions. Overall, the molecular analysis suggests that db/db mice have a longer inflammatory phase of the wound repair process, delaying the progression toward the proliferation and remodeling phases. [ABSTRACT FROM AUTHOR]

We aimed to evaluate the effects of Panax notoginseng saponin on neuronal apoptosis and neuroprotection based on oxygen-glucose deprivation/reoxygenation in rats with focal cerebral ischemia. 100 rats were randomly divided into sham operation, middle cerebral artery occlusion model, low-dose Panax notoginseng saponin (10 mg/kg), medium-dose Panax notoginseng saponin (25 mg/kg) and high-dose Panax notoginseng saponin (50 mg/kg) groups. The model of focal cerebral ischemia was established by middle cerebral artery occlusion. For sham group, the right common, external and internal carotid arteries were only dissociated, without ligation or insertion. After modeling, Panax notoginseng saponin groups were intraperitoneally injected with Panax notoginseng saponin. Hippocampal neurons isolated from normal rats were randomly divided into control, oxygen-glucose deprivation/reoxygenation model, 1 μmol/l, 5 μmol/l and 20 μmol/l oxygen-glucose deprivation/reoxygenation+Panax notoginseng saponin groups. Neurological function was scored by Longa method and neuron morphology was observed. Neuronuclear antigen and neuroepithelial stem protein in brain tissues were detected by immunohistochemistry. The survival rate of neurons, lactate dehydrogenase leakage, neuronal apoptosis and expression levels of protein kinase B, phosphorylatedprotein kinase B and apoptosis-related proteins B-cell lymphoma 2, Bcl-2-associated X protein and caspase-3 were examined by cell counting kit-8 assay, lactate dehydrogenase kit, Hoechst 33 342 staining and Western blotting, respectively. Compared with model group, Panax notoginseng saponin groups had significantly lower neurological function scores (p<0.05). Panax notoginseng saponin significantly relieved neuronal injury and increased neuronuclear and neuroepithelial stem protein-positive cells (p<0.05). It significantly raised the survival rate of neurons, reduced lactate dehydrogenase leakage and inhibited neuronal apoptosis dose-dependently. Panax notoginseng saponin up-regulated the protein expressions of phosphorylated-protein kinase B/protein kinase B and B-cell lymphoma 2 and down-regulated those of Bcl2-associated X protein and caspase-3 dose-dependently. It can protect against and repair neuronal injury caused by oxygen-glucose deprivation/reoxygenation, probably by activating the phosphatidylinositol 3-kinase/protein kinase B signaling pathway to suppress neuronal apoptosis. [ABSTRACT FROM AUTHOR]

Rosmarinic acid, a common ester extracted from Rosemary, Perilla frutescens, and Salvia miltiorrhiza Bunge, has been shown to have protective effects against various diseases. This is an investigation into whether rosmarinic acid can also affect the changes of white matter fibers and cognitive deficits caused by hypoxic injury. The right common carotid artery of 3-day-old rats was ligated for 2 hours. The rats were then prewarmed in a plastic container with holes in the lid, which was placed in 37°C water bath for 30 minutes. Afterwards, the rats were exposed to an atmosphere with 8% O2 and 92% N2 for 30 minutes to establish the perinatal hypoxia/ischemia injury models. The rat models were intraperitoneally injected with rosmarinic acid 20 mg/kg for 5 consecutive days. At 22 days after birth, rosmarinic acid was found to improve motor, anxiety, learning and spatial memory impairments induced by hypoxia/ischemia injury. Furthermore, rosmarinic acid promoted the proliferation of oligodendrocyte progenitor cells in the subventricular zone. After hypoxia/ischemia injury, rosmarinic acid reversed to some extent the downregulation of myelin basic protein and the loss of myelin sheath in the corpus callosum of white matter structure. Rosmarinic acid partially slowed down the expression of oligodendrocyte marker Olig2 and myelin basic protein and the increase of oligodendrocyte apoptosis marker inhibitors of DNA binding 2. These data indicate that rosmarinic acid ameliorated the cognitive dysfunction after perinatal hypoxia/ischemia injury by improving remyelination in corpus callosum. This study was approved by the Animal Experimental Ethics Committee of Xuzhou Medical University, China (approval No. 20161636721) on September 16, 2017.

Peroxisome proliferator-activated receptor (PPAR) β/δ belongs to the family of hormone and lipid-activated nuclear receptors, which are involved in metabolism of long-chain fatty acids, cholesterol, and sphingolipids. Similar to PPAR-α and PPAR-γ, PPAR-β/δ also acts as a transcription factor activated by dietary lipids and endogenous ligands, such as long-chain saturated and polyunsaturated fatty acids, and selected lipid metabolic products, such as eicosanoids, leukotrienes, lipoxins, and hydroxyeicosatetraenoic acids. Together with other PPARs, PPAR-β/δ displays transcriptional activity through interaction with retinoid X receptor (RXR). In general, PPARs have been shown to regulate cell differentiation, proliferation, and development and significantly modulate glucose, lipid metabolism, mitochondrial function, and biogenesis. PPAR-β/δ appears to play a special role in inflammatory processes and due to its proangiogenic and anti-/pro-carcinogenic properties, this receptor has been considered as a therapeutic target for treating metabolic syndrome, dyslipidemia, carcinogenesis, and diabetes. Until now, most studies were carried out in the peripheral organs, and despite of its presence in brain cells and in different brain regions, its role in neurodegeneration and neuroinflammation remains poorly understood. This review is intended to describe recent insights on the impact of PPAR-β/δ and its novel agonists on neuroinflammation and neurodegenerative disorders, including Alzheimer's and Parkinson's, Huntington's diseases, multiple sclerosis, stroke, and traumatic injury. An important goal is to obtain new insights to better understand the dietary and pharmacological regulations of PPAR-β/δ and to find promising therapeutic strategies that could mitigate these neurological disorders. [ABSTRACT FROM AUTHOR]

Background: Neonatal encephalopathy often leads to lifelong disabilities with limited treatments currently available. The brain vasculature is an important factor in many neonatal neurological disorders but there is a lack of diagnostic tools to evaluate the brain vascular dysfunction of neonates in the clinical setting. Measurement of blood–brain barrier tight-junction (TJ) proteins have shown promise as biomarkers for brain injury in the adult. Here we tested the biomarker potential of tight-junctions in the context of neonatal brain injury. Methods: The levels of TJ-proteins (occluding, claudin-5, and zonula occludens protein 1) in both blood plasma and cerebrospinal fluid (CSF) as well as blood–brain barrier function via 14C-sucrose (342 Da) and Evans blue extravasation were measured in a hypoxia/ischemia brain-injury model in neonatal rats. Results: Time-dependent changes of occludin and claudin-5 levels could be measured in blood and CSF after hypoxia/ischemia with males generally having higher levels than females. The levels of claudin-5 in CSF correlated with the severity of the brain injury at 24 h post- hypoxia/ischemia. Simultaneously, we detected early increase in blood–brain barrier-permeability at 6 and 24 h after hypoxia/ischemia. Conclusions: Levels of circulating claudin-5 and occludin are increased after hypoxic/ischemic brain injuries and blood–brain barrier-impairment and have promise as early biomarkers for cerebral vascular dysfunction and as a tool for risk assessment of neonatal brain injuries. [ABSTRACT FROM AUTHOR]

Each year, 1 million children die due to perinatal asphyxia; however, there are no effective drugs to protect the neonatal brain against hypoxic/ischemic damage. In this study, we demonstrated for the first time the neuroprotective capacity of 3,3'-diindolylmethane (DIM) in an in vivo model of rat perinatal asphyxia, which has translational value and corresponds to hypoxic/ischemic episodes in human newborns. Posttreatment with DIM restored the weight of the ipsilateral hemisphere and normalized cell number in the brain structures of rats exposed to perinatal asphyxia. DIM also downregulated the mRNA expression of HIF1A-regulated Bnip3 and Hif1a which is a hypoxic marker, and the expression of miR-181b which is an indicator of perinatal asphyxia. In addition, DIM inhibited apoptosis and oxidative stress accompanying perinatal asphyxia through: downregulation of FAS, CASP-3, CAPN1, GPx3 and SOD-1, attenuation of caspase-9 activity, and upregulation of anti-apoptotic Bcl2 mRNA. The protective effects of DIM were accompanied by the inhibition of the AhR and NMDA signaling pathways, as indicated by the reduced expression levels of AhR, ARNT, CYP1A1, GluN1 and GluN2B, which was correlated with enhanced global DNA methylation and the methylation of the Ahr and Grin2b genes. Because our study provided evidence that in rat brain undergoing perinatal asphyxia, DIM predominantly targets AhR and NMDA, we postulate that compounds that possess the ability to inhibit their signaling are promising therapeutic tools to prevent stroke. [ABSTRACT FROM AUTHOR]

Objectives: A drastic reduction in myocardial cell apoptosis plays a crucial role in the treatment/management of myocardial infarction, a major cardiovascular health challenge confronting the world, especially the Western world. Accumulating evidence indicates that the cardiotoxicity caused by the apoptotic machinery is partly regulated by miRNAs. The aim of this research is to investigate the role of miR-138-5p on hypoxia/reperfusion-induced heart injury. Methods: The expression of miR-138-5p was determined in heart tissue from myocardial infarction patients and rats. Rats were transfection with a miR-138-5p inhibitor to silence miR-138-5p. The cardiac function of rats was detected via echocardiography. SIRT1 and PGC-1α expression in cardiac infarction was detected via quantitative Real-time PCR (qPCR) and Western blot analysis, while the TUNEL assay was used to determine myocardial apoptosis. Results: Our observations showed that miR-138-5p expression was upregulated after the induction of myocardial infarction. The miR-138-5p inhibitor significantly improved cardiac function, increased the expression of SIRT1 and PGC-1α, and decreased the rate of myocardial apoptosis, whereas siRNA-SIRT1 reversed these protective effects. Conclusions: In conclusion, our study demonstrated that miR-138-5p could promote cardiac ischemia injury via inhibition of the silent information regulator 1 and peroxisome proliferator-initiated receptor gamma and coactivator 1 alpha (SIRT1–PGC-1α) axis. [ABSTRACT FROM AUTHOR]

The water contents of individual organs are maintained in a narrow range, but altered in morbidity owing to a disturbance of water equilibrium. The present study investigated the tissue water contents of major organs with regard to the cause of death in serial autopsy cases within 3 days postmortem (n = 329; 223 males, 106 females; age range, 1-100 years). Individual tissue water contents differed markedly across organs, but no significant postmortem or survival-period dependence, gender-related difference, or age dependence was observed. However, the lung water contents were higher in drowning cases, especially in saltwater cases (p < 0.05), and in strangulation among the acute mechanical asphyxiation cases. The brain water contents were higher in hypothermia cases (cold exposure) and tended to be higher in hyperthermia cases (heatstroke). The kidney water contents were higher in drowning and acute cardiac cases than in fatal intoxication and fire fatality cases, but tended to be higher in fresh- and bathwater drowning cases than in saltwater cases (p > 0.05). The spleen water contents were higher in bathwater drowning than in saltwater and freshwater cases, but did not differ among other the causes of death. These findings suggest that the postmortem tissue water content of individual organs, especially the lungs and/or kidney, depends on the cause of death and particularly contributes to differentiation between saltwater and freshwater drowning, respectively. This work therefore provides insight into the investigation of varied tissue water imbalances during the death process. In conclusion, we recommend the measurement of tissue water content because it is easy to perform and appears to be useful for evaluating the pathophysiology of systemic circulatory failure. [ABSTRACT FROM AUTHOR]

This study aimed to characterize the pathophysiology, including possible correlations, of clock gene expression and erythropoietin (EPO) production in the acute stage of blood hemorrhage. Specimens of human cortical tissues (right and left kidneys) and cardiac blood were collected at autopsy from 52 cases following mortality due to acute-stage blood hemorrhage following sharp instrument injury. BMAL1 and PER2 mRNA levels were determined by reverse transcription-polymerase chain reaction; BMAL1 and PER2 protein levels were assessed using immunohistochemistry; BMAL1 protein levels were quantitatively measured by western blotting; and serum EPO levels were measured by chemiluminescent enzyme immunoassay. Separately, a rat model of hemorrhagic conditions was generated and used to confirm the results obtained with autopsy-derived specimens. A positive correlation was observed between BMAL1 protein and serum EPO levels, but not between BMAL1 mRNA levels and serum EPO levels. We also noted that Per2 mRNA expression became elevated in humans who survived for > 3 h after acute hemorrhagic events, with subsequent decreases in serum EPO levels. The rat model showed that even short (30-min) intervals of blood loss yielded increases in both Bmal1 mRNA and serum EPO levels; longer (60-min) intervals resulted in increases in Per2 mRNA expression along with decreases in serum EPO. Thus, the acute-stage human hemorrhage cases and the rat hemorrhage model yielded similar tendencies for clock gene expression and EPO secretion. In conclusion, our results indicated that clock genes are involved in the regulation of EPO production during the early stages of hypoxia/ischemia resulting from the acute hemorrhagic events. [ABSTRACT FROM AUTHOR]

Background/Aims: Ginsenoside Rb1 (GS-Rb1) is one of the most important active pharmacological extracts of the Traditional Chinese Medicine ginseng, with extensive evidence of its cardioprotective properties. Mir-208 has been shown to act as a biomarker of acute myocardial infarction in vivo studies including man. However the impact of miR-208 on the protective effect of GS-Rb1 in hypoxia/ischemia injured cardiomyocytes remains unclear. The current study aims to investigate the target gene of miR-208 and the impact on the protective effect of GS-Rb1 in hypoxia/ischemia (H/I) injuried cardiomyocytes. Materials and Methods: Primary cultures of neonatal rat cardiomyocytes (NRCMs) was subjected to the H/I conditions with or without GS-Rb1. Cell viability was calculated by MTT assay and confirmed by flow cytometry analysis. Mir-208 was then detected by qRT-PCR. Luciferase reporter assay was carried out to detect the target gene of Mir-208. Then the NRCMs were transfected with miR-208 mimics and inhibitors to evaluate the impact on cardioprotective properties of Rb1. Results: The miR-208 expression level was clearly upregulated in the H/I treated NRCMs accompanied by the percentage of the apoptotic cells which could be reversed by GS-Rb1 pretreatment. The nemo-like kinase (NLK) mRNA and protein expression levels were decreased in H/I group measured by RT-PCR and western blotting. Luciferase activity assay was then carried out to identify that NLK may be a direct target of mir-208. MTT assay showed that miR-208 inhibitor slightly decreased the protective effect of Rb1 on the H/I impaired NRCMs. However, results showed no statistical difference. Conclusions: These findings proved that NLK was a direct target of mir-208 and miR-208 act indirectly during Rb1 protecting H/I impaired NRCMs and further researches were needed to explore the relationship that microRNAs and other signal pathways in the protective effect of GS-Rb1 on the hypoxia/ischemia injuries in cardiomyocytes.

Omega-3 polyunsaturated fatty acids (n‐3 PUFAs) have been shown to protect the neonatal brain against hypoxic/ischemic (H/I) injury. However, the mechanism of n‐3 PUFA-afforded neuroprotection is not well understood. One major determinant of H/I vulnerability is the permeability of the blood–brain barrier (BBB). Therefore, we examined the effects of n‐3 PUFAs on BBB integrity after neonatal H/I. Female rats were fed a diet with or without n‐3 PUFA enrichment from day 2 of pregnancy to 14 days after parturition. H/I was introduced in 7 day-old offspring. We observed relatively rapid BBB penetration of the small molecule cadaverine (640 Da) at 4 h post-H/I and a delayed penetration of larger dextrans (3 kD–40 kD) 24–48 h after injury. Surprisingly, the neonatal BBB was impermeable to Evans Blue or 70 kD dextran leakage for up to 48 h post-H/I, despite evidence of IgG extravasation at this time. As expected, n‐3 PUFAs ameliorated H/I-induced BBB damage, as shown by reductions in tracer efflux and IgG extravasation, preservation of BBB ultrastructure, and enhanced tight junction protein expression. Furthermore, n‐3 PUFAs prevented the elevation in matrix metalloproteinase (MMP) activity in the brain and blood after H/I. Thus, n‐3 PUFAs may protect neonates against BBB damage by blunting MMPs activation after H/I.

Liver hypoxia/ischemia injury leads to acute liver injury, delayed graft dysfunction, and failure during liver transplantation. Previous studies showed that autophagy is involved in liver hypoxia/ischemia injury. Our and others' studies have found that the damage-regulated autophagy modulator (DRAM) could induce the autophagic apoptosis. However, the role of DRAM regulating autophagy in liver hypoxia/ischemia injury remains unclear. The aim of this study was to determine whether DRAM is involved in oxygen-glucose deprivation (OGD)- induced hepatocyte autophagic apoptosis. Normal hepatocytes (HL-7702) were treated with OGD while Balb/c mice underwent surgery to induce 70% liver ischemia. To evaluate the role of DRAM in hypoxia/ischemiainduced hepatic injury, DRAM siRNA was used to knockdown DRAM expression in cultured hepatocytes and a recombinant adenovirus vector expressing DRAM was used to overexpress DRAM in cultured hepatocytes in vitro and in the liver in vivo. Hepatic injury was analyzed by histopathological methods and measurement of hepatocyte enzyme release. Cell apoptosis was analyzed by flow cytometry and TUNEL staining. Several autophagic biomarkers were observed by western blot analysis. OGD and 70% hepatic ischemia significantly induced cell autophagy, apoptosis and DRAM expression in hepatocytes in vitro and in vivo. OGD-induced autophagic apoptosis was inhibited by 3-Methyladenine (3-MA). OGD-induced injury and autophagy in HL-7702 cells were significantly attenuated by DRAM knockdown but aggravated by DRAM overexpression in vitro. Similarly, DRAM overexpression increased ischemia-induced liver injury and hepatic apoptosis in vivo. Our data demonstrate that hypoxia/ischemia induces hepatic injury through a DRAM-dependent autophagic apoptosis pathway. These data also suggest that DRAM plays an important role in ischemia-induced liver injury and hepatocyte apoptosis. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract The endocannabinoid system exerts a crucial neuromodulatory role in many brain areas that is essential for proper regulation of neuronal activity. The role of cannabinoid signalling controlling neuronal activity in the adult brain is also evident when considering its contribution to adult brain insults or neurodegenerative diseases. In the context of brain genetic or acquired encephalopathies administration of cannabinoid-based molecules has demonstrated to exert symptomatic relief and hence, they are proposed as new potential therapeutic compounds. This review article summarizes the main evidences indicating the beneficial action of cannabinoid-derived molecules in preclinical models of neonatal hypoxia/ischemic damage. In a second part, we discuss the available evidences of therapeutic actions of cannabidiol in children with refractory epilepsy syndromes. Finally, we discuss the current view of cannabinoid signalling mechanisms active in the immature brain that affect in neural cell fate and can contribute to long-term neural cell plasticity. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: The precise mechanisms of the inflammatory responses after cerebral ischemia in vivo are difficult to elucidate because of the complex nature of multiple series of interactions between cells and molecules. This study explored temporal patterns of secretion of 30 cytokines and chemokines from Sprague Dawley rat astrocytes in primary culture in order to elucidate signaling pathways that are triggered by astrocytes during anoxia. Methods: Primary cultures of rat brain astrocytes were incubated for periods of 2–24 hr in the absence of oxygen (anoxia) or under normal partial pressure of oxygen (controls). Simultaneous detection of 29 cytokines and chemokines in the samples was performed using a rat cytokine array panel, while the temporal pattern of angiopoietin‐1 (Ang‐1) secretion was determined separately using ELISA. Wilcoxon–Mann–Whitney test was used to compare normoxic and anoxic samples and the Hodge–Lehman estimator with exact 95% confidence intervals was computed to assess the size of differences in cytokine secretion. The obtained data were imported into the Core Analysis tool of Ingenuity Pathways Analysis software in order to relate changes in secretion of cytokines and chemokines from astrocytes during anoxia to potential molecular signal networks. Results: With the exception of Ang‐1, concentrations of all cytokines/chemokines in samples collected after anoxia exposure were either the same, or higher, than in control groups. No clear pattern of changes could be established for groups of cytokines with similar effects (i.e., pro‐ or anti‐inflammatory cytokines). The pattern of changes in cytokine secretion during anoxia was associated with the HIF‐1α‐mediated response, as well as cytokines IL‐1β and cathepsin S pathways, which are related to initiation of inflammation and antigen presentation, respectively, and to ciliary neurotrophic factor. Conclusions: These in vitro findings suggest that astrocytes may play a role in triggering inflammation during anoxia/ischemia of the brain. [ABSTRACT FROM AUTHOR]

Aim: to study characteristics of electrophysiological cardiac activity in children of risk groups and to assess possibilities of Holter-electrocardiography (H-ECG) in revealing of cardiac dysfunction during the period of early adaptation. Patients and methods: 250 newborns were examined. The main group consisted of 200 children with cerebral ischemia (CI). This group was divided into 2 subgroups: 100 full-term and 100 premature (at various gestation age) infants. Control group contained 50 children born at 38–40th weeks of gestation with physiological course of pregnancy and delivery, APGAR score of 8–9 points. Complex examination included H-ECG according the standard technic with evaluation of the hearth rate (HR) during sleep and wakefulness; HRmin, HRmax; arrhythmias, conductivity disorders, duration of the intervals; rhythm variability. Results: according to the ECG children with CI, especially premature ones, and children delivered via Cesarean section more often had ST-T disturbances, arrhythmias (sinus tachycardia, less often — sinus bradycardia) and conductivity disorders, Q-Tc prolongation. H-EGC revealed decrease of sleep HR, HRmin and HRmax in children with CI especially in delivered via Cesarean section. The most common arrhythmia was supraventricular extrasystole. Pauses in rhythms and variability were the highest in premature children delivered via Cesarean section. Conclusions: hypoxia/ischemia is a trigger for development of cardiovascular dysfuncion in newborns. Premature and children delivered via Cesarean section form a group of high risk. H-ECG widens possibilities of revealing of symptoms of cardiac dysfunction (disturbances at the basal level of functioning, of adaptation resources of the sinus node, electric instability of the myocardium and heart rate variability) in children of risk group for development of cardiovascular disorders.

Stimulation of endogenous neurogenesis and recruitment of neural progenitors from the subventricular zone (SVZ) neurogenic site may represent a useful strategy to improve regeneration in the ischemic cortex. Here, we tested whether transgenic overexpression of extracellular matrix metalloproteinase inducer (EMMPRIN), the regulator of matrix metalloproteinases (MMPs) expression, in endogenous neural progenitor cells (NPCs) in the subventricular zone (SVZ) could increase migration towards ischemic injury. For this purpose, we applied a lentivector-mediated gene transfer system. We found that EMMPRIN-transduced progenitors exhibited enhanced MMP-2 activity in vitro and showed improved motility in 3D collagen gel as well as in cortical slices. Using a rat model of neonatal ischemia, we showed that EMMPRIN overexpressing SVZ cells invade the injured cortical tissue more efficiently than controls. Our results suggest that EMMPRIN overexpression could be suitable approach to improve capacities of endogenous or transplanted progenitors to invade the injured cortex. [ABSTRACT FROM AUTHOR]

Dexamethasone, a synthetic glucocorticoid, has been widely used to prevent or ameliorate morbidity of chronic lung disease in preterm infants with respiratory distress syndrome. Despite its beneficial effect on neonatal lung function, growing concern has arisen about adverse effects of this clinical practice on fetal brain development. We demonstrated previously that neonatal dexamethasone (DEX) treatment may render the newborn brain to be more vulnerable to hypoxia/ischemia (HI)-induced gray matter injury. Here, we examined whether neonatal DEX treatment may also affect the extent of HI-induced subcortical white matter (WM) injury in the developing rat brain. Using a HI model of premature brain injury, we demonstrated that a 3-day tapering course (0.5, 0.3, and 0.1 mg/kg) of DEX treatment in rat pups on postnatal days 1-3 (P1-3) significantly reduced the number of all stages of the oligodendroglial lineage cells on P7 and exacerbated HI-induced WM injury. Neonatal DEX treatment also enhanced HI-induced oligodendroglial apoptosis and astrocyte activation in the developing WM on P14. Likewise, HI-induced reductions in myelin thickness, axon caliber, and function during WM development were exacerbated by neonatal DEX treatment. Furthermore, neonatal DEX treatment further aggravated HI-induced motor deficits as assessed in the rotarod test. We also found that the administration of β-lactam antibiotic ceftriaxone increased glutamate transporter-1 protein expression and significantly reduced HI-induced WM injury in neonatal DEX-treated rats. These results suggest that neonatal DEX treatment may lead the developing brain to be more vulnerable to subsequent HI-induced WM injury, which can be ameliorated by ceftriaxone administration. [ABSTRACT FROM AUTHOR]

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This review analyzes recent data on mechanisms of cerebral hypoxia and the protective methods of hypoxic and ischemic postconditioning, as well as their interrelationship with the key mechanisms responsible for neuroprotection and neuroplasticity. Upregulation of expression of antiapoptotic factors and neurotrophins and modulation of activity of several protein kinases and transcription factors such as hypoxia-inducible factor-1 (HIF-1) are considered as the most important aspects in the neuroprotective potential of postconditioning. The presented information indicates substantial transformative promise of the noninvasive techniques of hypoxic postconditioning as well as significant similarity between the adaptive pathways activated by various postconditioning methods, which are far from being fully understood. [ABSTRACT FROM AUTHOR]

A hypoxia/ischemia neuronal model was established in PC12 cells using oxygen-glucose deprivation (OGD). OGD-induced neuronal death, apoptosis, glutamate receptor subunit GluR2 expression, and potassium channel currents were evaluated in the present study to determine the effects of genistein in mediating the neuronal death and apoptosis induced by hypoxia and ischemia, as well as its underlying mechanism. OGD exposure reduced the cell viability, increased apoptosis, decreased the GluR2 expression, and decreased the voltage-activated potassium currents. Genistein partially reversed the effects induced by OGD. Therefore, genistein may prevent hypoxia/ischemic-induced neuronal apoptosis that is mediated by alterations in GluR2 expression and voltage-activated potassium currents. [ABSTRACT FROM AUTHOR]

Background/Aims: Ginsenoside Rb1 (GS-Rb1) is one of the most important active pharmacological extracts of the Traditional Chinese Medicine ginseng, with extensive evidence of its cardioprotective properties. Mir-208 has been shown to act as a biomarker of acute myocardial infarction in vivo studies including man. However the impact of miR-208 on the protective effect of GS-Rb1 in hypoxia/ischemia injured cardiomyocytes remains unclear. The current study aims to investigate the target gene of miR-208 and the impact on the protective effect of GS-Rb1 in hypoxia/ischemia (H/I) injuried cardiomyocytes. Materials and Methods: Primary cultures of neonatal rat cardiomyocytes (NRCMs) was subjected to the H/I conditions with or without GS-Rb1. Cell viability was calculated by MTT assay and confirmed by flow cytometry analysis. Mir-208 was then detected by qRT-PCR. Luciferase reporter assay was carried out to detect the target gene of Mir-208. Then the NRCMs were transfected with miR-208 mimics and inhibitors to evaluate the impact on cardioprotective properties of Rb1. Results: The miR-208 expression level was clearly upregulated in the H/I treated NRCMs accompanied by the percentage of the apoptotic cells which could be reversed by GS-Rb1 pretreatment. The nemo-like kinase (NLK) mRNA and protein expression levels were decreased in H/I group measured by RT-PCR and western blotting. Luciferase activity assay was then carried out to identify that NLK may be a direct target of mir-208. MTT assay showed that miR-208 inhibitor slightly decreased the protective effect of Rb1 on the H/I impaired NRCMs. However, results showed no statistical difference. Conclusions: These findings proved that NLK was a direct target of mir-208 and miR-208 act indirectly during Rb1 protecting H/I impaired NRCMs and further researches were needed to explore the relationship that microRNAs and other signal pathways in the protective effect of GS-Rb1 on the hypoxia/ ischemia injuries in cardiomyocytes. [ABSTRACT FROM AUTHOR]

CXCL10, the chemokine with potent chemotactic activity on immune cells and other non-immune cells expressing its receptor CXCR3, has been demonstrated to involve in myocardial infarction, which was resulted from hypoxia/ischemia. The cardiac microvascular endothelial cells (CMECs) are the first cell type which is implicated by hypoxia/ischemia. However, the potential molecular mechanism by which hypoxia/ischemia regulates the expression of CXCL10 in CMECs remains unclear. In the present study, the expression of CXCL10 was firstly examined by real-time PCR and ELISA analysis. Several potential binding sites (BS) for transcription factors including NF-kappaB (NFkB), HIF1 alpha (HIF1α) and FoxO3a were identified in the promoter region of CXCL10 gene from −2000 bp to −1 bp using bioinformatics software. Luciferase reporter gene vectors for CXCL10 promoter and for activation of above transcription factors were constructed. The activation of NFkB, hypoxia-inducible transcription factor-1 alpha (HIF-1α) and FoxO3a was also analyzed by Western blotting. It was shown that the production of CXCL10 in CMECs was significantly increased by hypoxia/ischemia treatment, in parallel with the activation of CXCL10 promoter examined by reporter gene vector system. Furthermore, transcription factors including NFkB, HIF1α and FoxO3a were activated by hypoxia/ischemia in CMECs. However, over-expression of NFkB, but not that of HIF1α or FoxO3a, significantly promoted the activation of CXCL10 promoter reporter gene. These findings indicated that CXCL10 production in CMECs was significantly increased by hypoxia/ischemia, at least in part, through activation of NFkB pathway and subsequently binding to CXCL10 promoter, finally promoted the transcription of CXCL10 gene. [ABSTRACT FROM AUTHOR]

CXCL10 is a chemokine with potent chemotactic activity for immune and non-immune cells expressing its receptor CXCR3. Previous studies have demonstrated that CXCL10 is involved in myocardial infarction. However, the role of CXCL10 in cardiac microvascular endothelial cell (CMEC) regulation and related mechanisms remains unclear. In this study, we investigated the effects of CXCL10 on the CMEC migration and explored its potential molecular mechanism by wound healing, cell proliferation and viability analysis. Furthermore, migration-related signaling pathways, including FAK, Erk, p38 and Smad, were examined by Western blotting. We found that CXCL10 significantly promotes CMEC migration under normal conditions and during hypoxia/ischemia. However, no significant differences in CMEC proliferation and viability were observed with or without CXCL10 treatment. CXCL10-mediated CMEC migration was greatly blocked by treatment with an anti-CXCR3 antibody. Although CXCL10 treatment promoted phosphorylation and activation of the FAK, Erk, and p38 pathways during hypoxia/ischemia, CXCL10-mediated CMEC migration was significantly blocked by p38 and FAK inhibitors, but not by an Erk inhibitor. Furthermore, CXCL10-mediated FAK activation was suppressed by the p38 inhibitor. These findings indicated that the CXCL10/CXCR3 pathway promotes the migration of CMECs under normal conditions and during hypoxia/ischemia in a proliferation-independent manner, at least in part, through regulation of the p38/FAK pathways. [ABSTRACT FROM AUTHOR]

Despite greater understanding and improved management, seizures continue to be a major problem in childhood. Neonatal seizures are often refractory to conventional antiepileptic drugs, and can result in later life epilepsy and cognitive deficits, conditions for which there are no specific treatments. Hypoxic and/or ischemic encephalopathy (HIE) is the most common cause for neonatal seizures, and accounts for more than two-thirds of neonatal seizure cases. A better understanding of the cellular and molecular mechanisms is essential for identifying new therapeutic strategies that control the neonatal seizures and its cognitive consequences. This heavily relies on animal models that play a critical role in discovering novel mechanisms underlying both epileptogenesis and associated cognitive impairments. To date, a number of animal models have provided a tremendous amount of information regarding the pathophysiology of HIE-induced neonatal seizures. This review provides an overview on the most important features of the main animal models of HIE-induced seizures. In particular, we focus on the methodology of seizure induction and the characterizations of post-HIE injury consequences. These aspects of HIE-induced seizure models are discussed in the light of the suitability of these models in studying human HIE-induced seizures. [ABSTRACT FROM AUTHOR]

The mitochondrial ATPase Inhibitory Factor 1 (hereafter referred to as IF 1 ) blocks the reversal of the F 1 F o -ATPsynthase to prevent detrimental consumption of cellular ATP and associated demise. Herein, we infer further its molecular physiology by assessing its protective function in neurons during conditions of challenged homeostatic respiration. By adopting in vitro and in vivo protocols of hypoxia/ischemia and re-oxygenation, we show that a shift in the IF 1 :F 1 F o -ATPsynthase expression ratio occurs in neurons. This increased IF 1 level is essential to induce accumulation of the PTEN-induced putative kinase 1 (PINK-1) and recruitment of the mitophagic ubiquitin ligase PARK-2 to promote autophagic “control” of the mitochondrial population. In IF 1 overexpressing neurons ATP depletion is reduced during hypoxia/ischemia and the mitochondrial membrane potential (Δ Y m ) resilient to re-oxygenation as well as resistant to electrogenic, Ca 2+ dependent depolarization. These data suggest that in mammalian neurons mitochondria adapt to respiratory stress by upregulating IF 1 , which exerts a protective role by coordinating pro-survival cell mitophagy and bioenergetics resilience. [ABSTRACT FROM AUTHOR]

Matrix metalloproteinases (MMPs) are important in injury and recovery in ischemic injury. They are proteolytic enzymes that degrade all components of the extracellular matrix (ECM). They are secreted in a latent form, protecting the cell from damage, but once activated induce injury prior to rapid inactivation by four tissue inhibitors to metalloproteinases (TIMPs). Normally the constitutive enzymes, MMP-2 and membrane type MMP (MMP-14), are activated in a spatially specific manner and act close to the site of activation, while the inducible enzymes, MMP-3 and MMP-9, become active through the action of free radicals and other enzymes during neuroinflammation. Because of the complex nature of the interactions with tissues during development, injury and repair, the MMPs have multiple roles, participating in the injury process in the early stages and contributing to recovery during the later stages. This dual role complicates the planning of treatment strategies. This article is part of a Special Issue entitled SI: Cell Interactions In Stroke . [ABSTRACT FROM AUTHOR]

Aims We aim to determine the significant effect of TPEN, a Zn2+ chelator, in mediating the pathophysiological cascade in neuron death/apoptosis induced by hypoxia/ischemia. Methods We conducted both in vivo and in vitro experiments in this study. PC12 cells were used to establish hypoxia/ischemia model by applying oxygen-glucose deprivation ( OGD). SHR- SP rats were used to establish an acute ischemic model by electrocoagulating middle cerebral artery occlusion. The effect of TPEN on neuron death/apoptosis was evaluated. In addition, the relative biomarks of excitotoxicity, oxidative stress, and inflammation reactions in hypoxia/ischemia PC12 cell model as well as in SHR- SP rat hypoxia/ischemia model were also assessed. Results TPEN significantly attenuates the neurological deficit, reduced the cerebral infarction area and the ratio of apoptotic neurons, and increased the expression of GluR2 in the rat hypoxia/ischemia brain. TPEN also increased blood SOD activity, decreased blood NOS activity and blood MDA and IL-6 contents in rats under hypoxia/ischemia. In addition, TPEN significantly inhibited the death and apoptosis of cells and attenuated the alteration of GluR2 and NR2 expression caused by OGD or OGD plus high Zn2+ treatments. Conclusions Zn2+ is involved in neural cell apoptosis and/or death caused by hypoxia/ischemia via mediating excitotoxicity, oxidative stress, and inflammation. [ABSTRACT FROM AUTHOR]

Stroke is a leading cause of death, disability, and socioeconomic loss worldwide. All attempts at pharmacological reduction of the complications of stroke (e.g. post-stroke seizure, and brain׳s vulnerability to hypoxic/ischemic injury) have failed. Endogenous opioids and nitric oxide (NO) overproduction has been documented in brain hypoxia/ischemia (H/I), which can exert pro-convulsive effects. In this study, we aimed to examine the possible involvement of opioidergic and nitrergic pathways in the pathogenesis of post-stroke seizure. H/I was induced by right common carotid ligation and sham-operated mice served as controls. We demonstrated that right common carotid ligation decreases the threshold for clonic seizures induced by pentylenetetrazole (PTZ), a GABA antagonist. Furthermore, pro-convulsive effect of H/I following right common carotid ligation was blocked by naltrexone (NTX) (3 mg/kg), NG-Nitro- l -arginine methyl ester ( l -NAME) (10 mg/kg), and aminoguanidine (AG) (100 mg/kg) administration ( P <0.001). Interestingly, co-administration of non-effective doses of NTX and l -NAME (1 and 0.5 mg/kg, respectively) reverses epileptogenesis of H/I ( P <0.001). In the same way, co-administration of non-effective doses of NTX and AG (1 and 5 mg/kg, respectively), reverses epileptogenesis of H/I ( P <0.001). Indeed, the histological studies performed on mice exposed to H/I confirmed our previous data. These findings suggest hyper-susceptibility to PTZ induced seizure following H/I is mediated by interaction of opioidergic, and iNOS/NO pathways. Therefore, our results identify new pharmacological targets and provide the rationale for a novel strategy to promote recovery after stroke and possibly other brain injuries. [ABSTRACT FROM AUTHOR]

Interventions to treat cerebral palsy should be initiated as soon as possible in order to restore the nervous system to the correct developmental trajectory. One drawback to this approach is that interventions have to undergo exceptionally rigorous assessment for both safety and efficacy prior to use in infants. Part of this process should involve research using animals but how good are our animal models? Part of the problem is that cerebral palsy is an umbrella term that covers a number of conditions. There are also many causal pathways to cerebral palsy, such as periventricular white matter injury in premature babies, perinatal infarcts of the middle cerebral artery, or generalized anoxia at the time of birth, indeed multiple causes, including intra-uterine infection or a genetic predisposition to infarction, may need to interact to produce a clinically significant injury. In this review, we consider which animal models best reproduce certain aspects of the condition, and the extent to which the multifactorial nature of cerebral palsy has been modeled. The degree to which the corticospinal system of various animal models human corticospinal system function and development is also explored. Where attempts have already been made to test early intervention in animal models, the outcomes are evaluated in light of the suitability of the model. [ABSTRACT FROM AUTHOR]

Background/Aims: Few studies address the long-term consequences of perinatal hypoxia (H), a frequent birth complication. Previously we described advanced reproductive senescence (premature loss of regular cyclicity) in female rats subjected to perinatal H or H plus unilateral ischemia (HI) associated with changes in the hypothalamic expression of estrogen and opioid receptors. Our aim is to explore whether hypothalamic inflammation and oxidative damage mediate these reproductive alterations. Methods: Female rats were subjected on postnatal day (PND) 7 to H (6.5% O2 for 50 min) or HI (H + right carotid artery ligature) and inflammation/oxidative damage markers, such as iNOS, nNOS, insulin-like growth factor (IGF) system expression, glial reaction and macrophage invasion in the medial basal hypothalamus-preoptic area (GFAP Western blot and immunohistochemistry, ED1 immunohistochemistry), were determined. The effect of antioxidant treatment with vitamin E (VE; 1.5 mg/rat on PND 4, 6 and 8) was also explored. Results: No significant cellular inflammatory reactions were observed although GFAP protein was significantly increased at early times after injury. Forty-eight hours after injury iNOS, nNOS and IGF-I mRNA decreased in the HI group, and nNOS in the H group. IGFBP-3 mRNA increased in HI rats at 48 h and 30 days, while it fell at 7 days postinjury in both groups. VE treatment prevented the effects of HI on oxidation/inflammation markers, but did not prevent the premature onset of reproductive senescence or the altered hormone receptors expression. Conclusion: These results suggest that the oxidative and inflammatory damage caused by perinatal H or HI may not be responsible for the late-onset reproductive abnormalities. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Hypoxia/ischemia and inflammation are two major mechanisms for cerebral palsy (CP) in preterm infants. Objective: To investigate whether hypoxia/ischemia- and infection-related events in the perinatal and neonatal periods had cumulative effects on CP risk in very-low-birth-weight (VLBW) premature infants. Methods: From 1995 to 2005, 5,807 VLBW preterm infants admitted to Taiwan hospitals were enrolled.The cumulative effects of hypoxic/ischemic and infectious events during the perinatal and neonatal periods on CP risk at corrected age 24 months were analyzed. Results: Of the 4,355 infants with 24-month follow-up, 457 (10.5%) had CP. The CP group had significantly higher incidences of hypoxia/ischemia-related events in the perinatal and neonatal periods, and sepsis in the neonatal period than the normal group. Three hypoxic/ischemic events, including birth cardiopulmonary resuscitation (OR 2.25; 95% CI 1.81-2.82), patent ductus arteriosus (PDA) ligation (2.94; 1.35-5.75) and chronic lung disease (3.14; 2.61-3.85) had the most significant contribution to CP. Relative to CP risk for infants with neither the three hypoxic/ischemic events nor sepsis, the CP odds increased 1.98-, 2.26- and 2.15-fold for infants with birth cardiopulmonary resuscitation, PDA ligation and chronic lung disease, respectively; while the combination with sepsis further increased the odds to 3.18-, 3.83- and 3.25-fold, respectively. Using the three hypoxic/ischemic events plus sepsis, CP rates were 10.0, 16.7, 26.7, 40.0 and 54.7% for infants with none, one, two, three and four events, respectively. Conclusions: Hypoxic/ischemic and infectious events across the perinatal and neonatal periods exerted cumulative effects on CP risk in VLBW premature infants. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]