• Title/Summary/Keyword: Hypoxic-ischemic

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Sertad1 Induces Neurological Injury after Ischemic Stroke via the CDK4/p-Rb Pathway

  • Li, Jianxiong;Li, Bin;Bu, Yujie;Zhang, Hailin;Guo, Jia;Hu, Jianping;Zhang, Yanfang
    • Molecules and Cells
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    • v.45 no.4
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    • pp.216-230
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    • 2022
  • SERTA domain-containing protein 1 (Sertad1) is upregulated in the models of DNA damage and Alzheimer's disease, contributing to neuronal death. However, the role and mechanism of Sertad1 in ischemic/hypoxic neurological injury remain unclear. In the present study, our results showed that the expression of Sertad1 was upregulated in a mouse middle cerebral artery occlusion and reperfusion model and in HT22 cells after oxygen-glucose deprivation/reoxygenation (OGD/R). Sertad1 knockdown significantly ameliorated ischemia-induced brain infarct volume, neurological deficits and neuronal apoptosis. In addition, it significantly ameliorated the OGD/R-induced inhibition of cell viability and apoptotic cell death in HT22 cells. Sertad1 knockdown significantly inhibited the ischemic/hypoxic-induced expression of p-Rb, B-Myb, and Bim in vivo and in vitro. However, Sertad1 overexpression significantly exacerbated the OGD/R-induced inhibition of cell viability and apoptotic cell death and p-Rb, B-Myb, and Bim expression in HT22 cells. In further studies, we demonstrated that Sertad1 directly binds to CDK4 and the CDK4 inhibitor ON123300 restores the effects of Sertad1 overexpression on OGD/R-induced apoptotic cell death and p-Rb, B-Myb, and Bim expression in HT22 cells. These results suggested that Sertad1 contributed to ischemic/hypoxic neurological injury by activating the CDK4/p-Rb pathway.

Imaging Hypoxic Myocardium (심근 저산소증 영상)

  • Bae, Sang-Kyun
    • The Korean Journal of Nuclear Medicine
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    • v.39 no.2
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    • pp.141-145
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    • 2005
  • Hypoxia (decreased tissue oxygen tension) is a component of many diseases such as tumors, cerebrovascular diseases and ischemic heart diseases. Although hypoxia can be secondary to a low inspired $pO_2$ or a variety of lung disorders, the most common cause is ischemia due to an oxygen demand greater than the local oxygen supply. In the heart tissue, hypoxia is often observed in persistent low-flow states, such as hibernating myocardium. Direct "hot spot" imaging of myocardial tissue hypoxia is potentially of great clinical importance because it may provide a means of identifying dysfunctional chronically ischemic but viable hibernating myocardium. A series of radiopharmaceuticals that incorporate nitroimidazole moieties have been synthesized to detect decreased local tissue pO2. In contrast to agents that localize in proportion to perfusion, these agents concentrate in hypoxic tissue. However, the ideal agents are not developed yet and the progress is very slow. Furthermore, the research focus is on tumor hypoxia nowadays. This review introduces the myocardial hypoxia imaging with summarizing the development of radiopharmaceuticals.

DENTAL TRAUMA FROM OROPHARYNGEAL AIRWAY IN CHILDREN WITH THE HYPOXIC ISCHEMIC ENCEPHALOPATHY : CASE REPORTS (저산소성 허혈성 뇌병변 환아에서 구인두 기도유지기에 의한 치아 손상 : 증례보고)

  • Lee, Mi-Yeon;Shin, Teo-Jeon;Hyun, Hong-Keun;Kim, Young-Jae;Kim, Jung-Wook;Jang, Ki-Taeg;Kim, Chong-Chul;Lee, Sang-Hoon
    • The Journal of Korea Assosiation for Disability and Oral Health
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    • v.9 no.2
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    • pp.127-130
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    • 2013
  • Hypoxic ischemic encephalopathy (HIE) is an important cause of permanent damage to central nervous system cells, most cases with oxygen deprivation in the nenonate due to birth asphyxia. Survival children with HIE develop problems such as cerebral palsy, mental retardation, learning difficulties, and other permanent neuro-developmental disabilities. This article report two cases of the children with HIE who had be traumatized on their teeth from oropharyngeal airway (OPA) in the emergency situation. The patients with the disease accompanying seizure or convulsion, needs special consideration for the prevention from dental trauma in emergency airway management.

Cognitive Dysfunction and Hippocampal Damage Induced by Hypoxic-Ischemic Brain Injury and Prolonged Febrile Convulsions in Immature Rats

  • Byeon, Jung Hye;Kim, Gun-Ha;Kim, Joo Yeon;Sun, Woong;Kim, Hyun;Eun, Baik-Lin
    • Journal of Korean Neurosurgical Society
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    • v.58 no.1
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    • pp.22-29
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    • 2015
  • Objective : Perinatal hypoxic-ischemic encephalopathy (HIE) and prolonged febrile seizures (pFS) are common neurologic problems that occur during childhood. However, there is insufficient evidence from experimental studies to conclude that pFS directly induces hippocampal injury. We studied cognitive function and histological changes in a rat model and investigated which among pFS, HIE, or a dual pathologic effect is most detrimental to the health of children. Methods : A rat model of HIE at postnatal day (PD) 7 and a pFS model at PD10 were used. Behavioral and cognitive functions were investigated by means of weekly open field tests from postnatal week (PW) 3 to PW7, and by daily testing with the Morris water maze test at PW8. Pathological changes in the hippocampus were observed in the control, pFS, HIE, and HIE+pFS groups at PW9. Results : The HIE priming group showed a seizure-prone state. The Morris water maze test revealed a decline in cognitive function in the HIE and HIE+pFS groups compared with the pFS and control groups. Additionally, the HIE and HIE+pFS groups showed significant hippocampal neuronal damage, astrogliosis, and volume loss, after maturation. The pFS alone induced minimal hippocampal neuronal damage without astrogliosis or volume loss. Conclusion : Our findings suggest that pFS alone causes no considerable memory or behavioral impairment, or cellular change. In contrast, HIE results in lasting memory impairment and neuronal damage, gliosis, and tissue loss. These findings may contribute to the understanding of the developing brain concerning conditions caused by HIE or pFS.

Curcumin targets vascular endothelial growth factor via activating the PI3K/Akt signaling pathway and improves brain hypoxic-ischemic injury in neonatal rats

  • Li, Jia;An, Yan;Wang, Jia-Ning;Yin, Xiao-Ping;Zhou, Huan;Wang, Yong-Sheng
    • The Korean Journal of Physiology and Pharmacology
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    • v.24 no.5
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    • pp.423-431
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    • 2020
  • This study aimed to evaluate the effect of curcumin on brain hypoxic-ischemic (HI) damage in neonatal rats and whether the phosphoinositide 3-kinase (PI3K)/Akt/vascular endothelial growth factor (VEGF) signaling pathway is involved. Brain HI damage models were established in neonatal rats, which received the following treatments: curcumin by intraperitoneal injection before injury, insulin-like growth factor 1 (IGF-1) by subcutaneous injection after injury, and VEGF by intracerebroventricular injection after injury. This was followed by neurological evaluation, hemodynamic measurements, histopathological assessment, TUNEL assay, flow cytometry, and western blotting to assess the expression of p-PI3K, PI3K, p-Akt, Akt, and VEGF. Compared with rats that underwent sham operation, rats with brain HI damage showed remarkably increased neurological deficits, reduced right blood flow volume, elevated blood viscosity and haematocrit, and aggravated cell damage and apoptosis; these injuries were significantly improved by curcumin pretreatment. Meanwhile, brain HI damage induced the overexpression of p-PI3K, p-Akt, and VEGF, while curcumin pretreatment inhibited the expression of these proteins. In addition, IGF-1 treatment rescued the curcumin-induced down-regulated expression of p-PI3K, p-Akt, and VEGF, and VEGF overexpression counteracted the inhibitory effect of curcumin on brain HI damage. Overall, pretreatment with curcumin protected against brain HI damage by targeting VEGF via the PI3K/Akt signaling pathway in neonatal rats.

The neuroprotective effect of recombinant human erythropoietin via an antiapoptotic mechanism on hypoxic-ischemic brain injury in neonatal rats

  • Kim, Moon-Sun;Seo, Yoo-Kyung;Park, Hye-Jin;Lee, Kye-Hyang;Lee, Kyung-Hoon;Choi, Eun-Jin;Kim, Jin-Kyung;Chung, Hai-Lee;Kim, Woo-Taek
    • Clinical and Experimental Pediatrics
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    • v.53 no.10
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    • pp.898-908
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    • 2010
  • Purpose: The neuroprotective effects of erythropoietin (EPO) have been recently shown in many animal models of brain injury, including hypoxic-ischemic (HI) encephalopathy, trauma, and excitotoxicity; however, limited data are available for such effects during the neonatal periods. Therefore, we investigated whether recombinant human EPO (rHuEPO) can protect against perinatal HI brain injury via an antiapoptotic mechanism. Methods: The left carotid artery was ligated in 7-day-old Sprague-Dawley (SD) rat pups ($in$ $vivo$ model). The animals were divided into 6 groups: normoxia control (NC), normoxia sham-operated (NS), hypoxia only (H), hypoxia+vehicle (HV), hypoxia+rHuEPO before a hypoxic insult (HE-B), and hypoxia+rHuEPO after a hypoxic insult (HE-A). Embryonic cortical neuronal cell culture of SD rats at 18 days gestation ($in$ $vitro$ model) was performed. The cultured cells were divided into 5 groups: normoxia (N), hypoxia (H), and 1, 10, and 100 IU/mL rHuEPO-treated groups. Results: In the $in$ $vivo$ model, Bcl-2 expressions in the H and HV groups were lower than those in the NC and NS groups, whereas those in the HE-A and HE-B groups were greater than those of the H and HV groups. The expressions of Bax and caspase-3 and the ratio of Bax/Bcl-2 were in contrast to those of Bcl-2. In the $in$ $vitro$ model, the patterns of Bcl-2, Bax, and caspase-3 expression and Bax/Bcl-2 ratio were similar to the results obtained in the in vivo model. Conclusion: rHuEPO exerts neuroprotective effect against perinatal HI brain injury via an antiapoptotic mechanism.

Upregulation of HIF-1α by Hypoxia Protect Neuroblastoma Cells from Apoptosis by Promoting Survivin Expression

  • Zhang, Bo;Yin, Cui-Ping;Zhao, Qian;Yue, Shou-Wei
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.19
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    • pp.8251-8257
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    • 2014
  • Apoptosis is one of main types of neural cell death and is reversible and is a major target of therapeutic interventions. However, detailed apoptotic cascades still need to be recognized. In present study, we determined the promotion of HIF-$1{\alpha}$ and survivin in brain samples of a mouse model of hypoxic-ischemia and in neuroblastoma SH-SY5Y cells post hypoxia treatment. Then gain-of-function and loss-of-function strategies were adopted to manipulate the HIF-$1{\alpha}$ in SH-SY5Y cells, and hypoxia-induced survivin upregulation and cell apoptosis were determined. Results demonstrated that the HIF-$1{\alpha}$ and survivin were significantly promoted in a mouse model of hypoxic-ischemia or in SH-SY5Y cells post hypoxia in vitro. Manually upregulated HIF-$1{\alpha}$ could promote the hypoxia-induced survivin upregulation and improve the hypoxia-induced SH-SY5Y cell apoptosis. On the other hand, the HIF-$1{\alpha}$ knockdown by RNAi reduced the hypoxia-induced survivin upregulation and cell apoptosis. Therefore, the present study confirmed the protective role of HIF-$1{\alpha}$ and survivin in the hypoxia-induced SH-SY5Y cell apoptosis, and the survivin upregulation by hypoxia is HIF-$1{\alpha}$-dependent. Promotion of HIF-$1{\alpha}$ and survivin might be a valuable stragegy for therapeutic intervention for hypoxic-ischemic encephalopathy.

Myoclonic status epilepticus in hypoxic ischemic encephalopathy which recurred after somatosensory evoked potential testing

  • Kim, Seongheon;Kim, Yeshin;Kim, Sunghun;Lee, Seo-Young
    • Annals of Clinical Neurophysiology
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    • v.19 no.2
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    • pp.136-140
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    • 2017
  • A 77-year-old male with amyotrophic lateral sclerosis had a hypoxic event. After resuscitation, generalized myoclonus appeared and resolved after two days. Five days after the hypoxic event, myoclonic seizures re-emerged right after performing a somatosensory evoked potential and persisted for ten days. Electroencephalogram revealed frequent bi-hemispheric synchronous spike and waves in the central areas. We suggest that somatosensory evoked potential testing may trigger myoclonic status epilepticus. Underlying cortical degeneration associated with amyotrophic lateral sclerosis could attribute to this phenomenon.