Disparate roles of zinc in chemical hypoxia-induced neuronal death

Kim, Sujeong,Seo, Jung-Woo,Oh, Shin Bi,Kim, So Hee,Kim, Inki,Suh, Nayoung,Lee, Joo-Yong Frontiers Media S.A. 2015 Frontiers in cellular neuroscience Vol.9 No.-

<P>Accumulating evidence has provided a causative role of zinc (Zn<SUP>2+</SUP>) in neuronal death following ischemic brain injury. Using a hypoxia model of primary cultured cortical neurons with hypoxia-inducing chemicals, cobalt chloride (1 mM CoCl<SUB>2</SUB>), deferoxamine (3 mM DFX), and sodium azide (2 mM NaN<SUB>3</SUB>), we evaluated whether Zn<SUP>2+</SUP> is involved in hypoxic neuronal death. The hypoxic chemicals rapidly elicited intracellular Zn<SUP>2+</SUP> release/accumulation in viable neurons. The immediate addition of the Zn<SUP>2+</SUP> chelator, CaEDTA or N,N,N’N’-tetrakis-(2-pyridylmethyl) ethylenediamine (TPEN), prevented the intracellular Zn<SUP>2+</SUP> load and CoCl<SUB>2</SUB>-induced neuronal death, but neither 3 hour later Zn<SUP>2+</SUP> chelation nor a non-Zn<SUP>2+</SUP> chelator ZnEDTA (1 mM) demonstrated any effects. However, neither CaEDTA nor TPEN rescued neurons from cell death following DFX- or NaN<SUB>3</SUB>-induced hypoxia, whereas ZnEDTA rendered them resistant to the hypoxic injury. Instead, the immediate supplementation of Zn<SUP>2+</SUP> rescued DFX- and NaN<SUB>3</SUB>-induced neuronal death. The iron supplementation also afforded neuroprotection against DFX-induced hypoxic injury. Thus, although intracellular Zn<SUP>2+</SUP> release/accumulation is common during chemical hypoxia, Zn<SUP>2+</SUP> might differently influence the subsequent fate of neurons; it appears to play a neurotoxic or neuroprotective role depending on the hypoxic chemical used. These results also suggest that different hypoxic chemicals may induce neuronal death via distinct mechanisms.</P>

백서의 심실세동성 심정지 모델에서 해마신경세포 손상에 대한 단백질 합성저해제의 효과

오동렬,채장성,박승현,김세경,최세민,박제영 대한응급의학회 2000 대한응급의학회지 Vol.11 No.4

Background: The goal of successful resuscitation is not only to stop the process of ischemia as soon as possible but also to overcome the secondary injury process after resuscitation, which involves a complex interplay of mechanisms. Brain damage accompanying cardiac arrest and resuscitation is frequent and devastating. Cells die by one of two mechanisms: necrosis or delayed neuronal death. Delayed neuronal death may require protein synthesis. Neurons in the CA1 subfield of the hippocampus are selectively vulnerable to death after injury by ischemia and reperfusion. Death of these neurons occurs after an interval of 1 or 2 days. We assessed the effects of a protein synthesis inhibitor, cycloheximide(CHX), on hippocampal neuronal death of rats by using the ventricular fibrillation cardiac arrest(VFCA) model. Methods: The effect of CHX(3 mg/kg, s.c.) on hippocampal neuronal death was studied in two groups of 18 rats each, one group being subjected to a 2-min VFCA and the other to a 3-min VFCA. Each group was divided into three subgroups: control(groupⅠ,Ⅱ) without subcutaneous injection of CHX, "esp-12" of group Ⅰ/Ⅱ treated with CHX 12 hours after return of spontaneous circulation (ROSC), and "exe-24" of group Ⅰ/Ⅱ treated with CHX 24 hours after ROSC. The coronal sections of the hippocampus levels were stained with hematoxylin-eosin after 72 hours of survival. The histologic damage score(HDS) was used to assign a score to the total number of damaged neurons counted in each of the hippocampal CA1 subfields. Results: 1. There were not significant differences in heart rates, blood pressures, blood sugar, and blood gas in group I & Ⅱ during the pre-arrest steady state or at 5 min and 30 min after ROSC. 2. In group I & Ⅱ, the HDS, were significantly reduced in rats(I exp-12, 1.1 ±0.6;Ⅰexp-24, 1.3 ±0.5;Ⅱ exp-12, 1.4±0.7; and Ⅱ exp-24, 1.8±0.8) treated with CHX 12 hours or 24 hours after ROSC than control rats(1,2.5 ±0.9;Ⅱ,2.9±0.8)(p<0.05). Conclusion: These results suggest that delayed hippocampal neuronal death from ischemic insult after ventricular fibrillation cardiac arrest followed by resuscitation can be prevented by a protein synthesis inhibitor, CHX. Further experimental studies of the action mechanism of protein synthesis inhibitors to delayed neuronal death and clinical applications are required.

Fate of Astrocytes in The Gerbil Hippocampus After Transient Global Cerebral Ischemia

Kim, Hyeyoung,Park, Joon Ha,Shin, Myoung Cheol,Cho, Jun Hwi,Lee, Tae-Kyeong,Kim, Hyunjung,Song, Minah,Park, Cheol Woo,Park, Young Eun,Lee, Jae-Chul,Ryoo, Sungwoo,Kim, Young-Myeong,Kim, Dae Won,Hwang, MDPI 2019 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.20 No.4

<P>Neuronal death and reactive gliosis are major features of brain tissue damage following transient global cerebral ischemia (tgCI). This study investigated long-term changes in neuronal death and astrogliosis in the gerbil hippocampus for 180 days after 5 min of tgCI. A massive loss of pyramidal neurons was found in the hippocampal CA1 area (CA1) area between 5 and 30 days after tgCI by Fluoro-Jade B (FJB, a marker for neuronal degeneration) histofluorescence staining, but pyramidal neurons in the CA2/3 area did not die. The reaction of astrocytes (astrogliosis) was examined by glial fibrillary acidic protein (GFAP) immunohistochemistry. Morphological change or degeneration (death) of the astrocytes was found in the CA1 area after tgCI, but, in the CA2/3 area, astrogliosis was hardly shown. GFAP immunoreactive astrocytes in the CA1 area was significantly increased in number with time and peaked at 30 days after tgCI, and they began to be degenerated or dead from 40 days after tgCI. The effect was examined by double immunofluorescence staining for FJB and GFAP. The number of FJB/GFAP<SUP>+</SUP> cells (degenerating astrocytes) was gradually increased with time after tgCI. At 180 days after tgCI, FJB/GFAP<SUP>+</SUP> cells were significantly decreased, but FJB<SUP>+</SUP> cells (dead astrocytes) were significantly increased. In brief, 5 min of tgCI induced a progressive degeneration of CA1 pyramidal neurons from 5 until 30 days with an increase of reactive astrocytes, and, thereafter, astrocytes were degenerated with time and dead at later times. This phenomenon might be shown due to the death of neurons.</P>

Gerbil 해마에서 일시적 대뇌허혈에 의한 신경세포의 Apotosis에 미치는 Zinc의 효과에 관한 면역조직학 및 전자현미경적 연구

임도선 ( Do Seon Lim ),배형준 ( Hyung Joon Bae ),김태전 ( Tae Jeon Kim ),강희규 ( Hee-gyu Kang ),양제훈 ( Je Hoon Yang ) 대한임상검사과학회 2003 대한임상검사과학회지(KJCLS) Vol.35 No.2

Zinc is one of the trace elements playing an important role in many fundamental biological process. The divalent cation zinc has been reported to possess several physiological properties such as blocking apoptotic cell death through an inhibitory effect on Ca²+, Mg²+ endonuclease activity, or modulating the neurotoxicity via glutamate receptor subtypes. In the present study, we investigated the effect of peripherally injected zinc on delayed neuronal cell death seen in the hippocampus after transient global ischemia, in order to elucidate a possible beneficial role on zinc in ischemic neuronal cell death. Forty adult Mongolian gerbils of male underwent transient bilateral clipping the common carotid arteries for 5 min. In the pretreated animals, ZnCl₂(20mg/kg) was injected subcutaneously once, 1hr before ischemia. Histological survey was carried out 4 days later by in situ DNA fragmentation method and hematoxylin-eosin staining by semiquantatively counting dead neurons in the CA1 sector. And ultrastructural study was also undertaken to determine the effect of zinc on the evolution of transient global ischemia-induced neuronal injury in the gerbil hippocampus. In histological and ultrastructural study, pretreatment of zinc significantly reduced the nuclear damage and subsequent neuronal death against ischemic damage. The result of the present study suggest that the pretreatment of zinc might be an effective tool for the treatment of cerebral ischemia.

Transient forebrain ischemia induces impairment in cognitive performance prior to extensive neuronal cell death in Mongolian gerbil (Meriones unguiculatus)

Tomohiro Kondo,Suguru Yoshida,Hiroaki Nagai,Ai Takeshita,Masaki Mino,Hiroshi Morioka,Takayuki Nakajima,Ken Takeshi Kusakabe,Toshiya Okada 대한수의학회 2018 Journal of Veterinary Science Vol.19 No.4

In Mongolian gerbils, bilateral common carotid artery occlusion (BCCAO) for several minutes induces ischemia, due to an incomplete circle of Willis, resulting in delayed neuronal cell death in the Cornet d’Ammon 1 (CA1) region of the hippocampus. Neuronal cell death in the hippocampus and changes in behavior were examined after BCCAO was performed for 5 min in the gerbils. One day after BCCAO, the pyramidal neurons of the CA1 region of the hippocampus showed degenerative changes (clumped chromatin in nuclei). At 5 and 10 days after BCCAO, extensive neuronal cell death was observed in the hippocampal CA1 region. Cognitive performance was evaluated by using the radial maze and passive avoidance tests. In the radial maze test, which examines win-stay performance, the number of errors was significantly higher in ischemic gerbils than in sham-operated gerbils on days 1 and 2 post-operation. In the passive avoidance test, the latency and freezing times were significantly shorter in ischemic gerbils than in sham-operated gerbils on the days 1, 2, and 4–6 post-operation. These results indicate that transient forebrain ischemia impairs cognitive performance, even immediately after the ischemic insult when there are only subtle signs of neuronal cell death.

흰쥐 해마에서 일시적 대뇌 허혈에 의한 glutamate 수용체 아형 유전자의 발현변동

이승한,김종근,배춘상,정윤영,조기현 全南大醫大 2001 전남의대학술지 Vol.37 No.3

Tumor necrosis factor receptor 2 is required for ischemic preconditioning-mediated neuroprotection in the hippocampus following a subsequent longer transient cerebral ischemia

Lee, Jae-Chul,Park, Chan Woo,Shin, Myoung Cheol,Cho, Jun Hwi,Lee, Hyang-Ah,Kim, Young-Myeong,Park, Joon Ha,Ahn, Ji Hyeon,Cho, Jeong Hwi,Tae, Hyun-Jin,Hwang, In Koo,Lee, Tae-Kyeong,Won, Moo-Ho,Kang, Il Elsevier 2018 Neurochemistry International Vol.118 No.-

<P><B>Abstract</B></P> <P>Tumor Necrosis Factor-α (TNF-α) is a proinflammatory cytokine implicated in neuronal damage in response to cerebral ischemia. Ischemic preconditioning (IPC) provides neuroprotection against a subsequent severer or longer transient ischemia by ischemic tolerance. Here, we focused on the role of TNF-α in IPC-mediated neuroprotection against neuronal death following a subsequent longer transient cerebral ischemia (TCI). Gerbils used in this study were randomly assigned to eight groups; sham group, TCI operated group, IPC plus (+) sham group, IPC + TCI operated group, sham + etanercept (an inhibitor of TNF-a) group, TCI + etanercept group, IPC + sham + etanercept group, and IPC + TCI + etanercept group. IPC was induced by a 2-min sublethal transient ischemia, which was operated 1 day prior to a longer (5-min) TCI. A significant death of neurons was found in the stratum pyramidale (SP) in the CA1 area (CA1) of the hippocampus 5 days after TCI; however, IPC protected SP neurons from TCI. We found that TNF-α immunoreactivity was significantly increased in CA1 pyramidal neurons in the TCI and IPC + TCI groups compared to the sham group. TNF-R1 expression in CA1 pyramidal neurons of the TCI group was also increased 1 and 2 days after TCI; however, in the IPC + TCI group, TNF-R1 expression was significantly lower than that in the TCI group. On the other hand, we did not detect TNF-R2 immunoreactivity in CA1 pyramidal neurons 1 and 2 days after TCI; meanwhile, in the IPC + TCI group, TNF-R2 expression was significantly increased compared to TNF-R2 expression at 1 and 2 days after TCI. In addition, in this group, TNF-R2 was newly expressed in pericytes, which are important cells in the blood brain barrier, from 1 day after TCI. When we treated etanercept to the IPC + TCI group, IPC-induced neuroprotection was significantly weakened. In brief, this study indicates that IPC confers neuroprotection against TCI by TNF-α signaling through TNF-R2 and suggests that the enhancement of TNF-R2 expression by IPC may be a legitimate strategy for a therapeutic intervention of TCI.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ischemic preconditioning (IPC) protects CA1 pyramidal neurons from ischemic damage. </LI> <LI> IPC attenuates TNF-α and TNF-R1 expressions in ischemic CA1 pyramidal neurons. </LI> <LI> IPC increases TNF-R2 expressions in pericytes in CA1 area after ischemic insult. </LI> <LI> IPC-mediated neuroprotective effect is reversed by etanercept (an inhibitor of TNF-a) treatment. </LI> </UL> </P>

Changes in the expression of DNA-binding/differentiation protein inhibitors in neurons and glial cells of the gerbil hippocampus following transient global cerebral ischemia

LEE, JAE-CHUL,CHEN, BAI HUI,CHO, JEONG-HWI,KIM, IN HYE,AHN, JI HYEON,PARK, JOON HA,TAE, HYUN-JIN,CHO, GEUM-SIL,YAN, BING CHUN,KIM, DAE WON,HWANG, IN KOO,PARK, JINSEU,LEE, YUN LYUL,CHOI, SOO YOUNG,WON, SPANDIDOS PUBLICATIONS 2015 MOLECULAR MEDICINE REPORTS Vol.11 No.4

<P>Inhibitors of DNA-binding/differentiation (ID) proteins bind to basic helix-loop-helix (bHLH) transcription factors, including those that regulate differentiation and cell-cycle progression during development, and regulate gene transcription. However, little is known about the role of ID proteins in the brain under transient cerebral ischemic conditions. In the present study, we examined the effects of ischemia-reperfusion (I-R) injury on the immunoreactivity and protein levels of IDs 1–4 in the gerbil hippocampus proper <I>Cornu Ammonis</I> regions CA1–3 following 5 min of transient cerebral ischemia. Strong ID1 immunoreactivity was detected in the nuclei of pyramidal neurons in the hippocampal CA1–3 regions; immunoreactivity was significantly changed following I-R in the CA1 region, but not in the CA2/3 region. Five days following I-R, ID1 immunoreactivity was not detected in the CA1 pyramidal neurons. ID1 immunoreactivity was detected only in GABAergic interneurons in the ischemic CA1 region. Weak ID4 immunoreactivity was detected in non-pyramidal cells, and immunoreactivity was again only changed in the ischemic CA1 region. Five days following I-R, strong ID4 immunoreactivity was detected in non-pyramidal cells, which were identified as microglia, and not astrocytes, in the ischemic CA1 region. Furthermore, changes in the protein levels of ID1 and ID4 in the ischemic CA1 region studied by western blot were consistent with patterns of immunoreactivity. In summary, these results indicate that immunoreactivity and protein levels of ID1 and ID4 are distinctively altered following transient cerebral ischemia only in the CA1 region, and that the changes in ID1 and ID4 expression may relate to the ischemia-induced delayed neuronal death.</P>

Pre- and post-treatments with escitalopram protect against experimental ischemic neuronal damage via regulation of BDNF expression and oxidative stress

Lee, Choong Hyun,Park, Joon Ha,Yoo, Ki-Yeon,Choi, Jung Hoon,Hwang, In Koo,Ryu, Pan Dong,Kim, Do-Hoon,Kwon, Young-Guen,Kim, Young-Myeong,Won, Moo-Ho Elsevier 2011 Experimental neurology Vol.229 No.2

<P><B>Abstract</B></P><P>Selective serotonin re-uptake inhibitors (SSRI) have been widely used in treatment of major depression because of their efficacy, safety, and tolerability. Escitalopram, an SSRI, is known to decrease oxidative stress in chronic stress animal models. In the present study, we examined the neuroprotective effects of pre- and post-treatments with 20mg/kg and 30mg/kg escitalopram in the gerbil hippocampal CA1 region (CA1) after transient cerebral ischemia. Pre-treatment with escitalopram protected against ischemia-induced neuronal death in the CA1 after ischemia/reperfusion (I/R). Post-treatment with 30mg/kg, not 20mg/kg, escitalopram had a neuroprotective effect against ischemic damage. In addition, 20mg/kg pre- and 30mg/kg post-treatments with escitalopram increased brain-derived neurotrophic factor (BDNF) protein levels in the ischemic CA1 compared to vehicle-treated ischemia animals. In addition, 20mg/kg pre- and 30mg/kg post-treatments with escitalopram reduced microglia activation and decreased 4-hydroxy-2-nonenal and Cu,Zn-superoxide dismutase immunoreactivity and their levels in the ischemic CA1 compared to vehicle-treated ischemia animals after transient cerebral ischemia. In conclusion, these results indicated that pre- and post-treatments with escitalopram can protect against ischemia-induced neuronal death in the CA1 induced by transient cerebral ischemic damage by increase of BDNF as well as decrease of microglia activation and oxidative stress.</P> <P><B>Research highlights</B></P><P>► Pre- and post-treatments with escitalopram protect against ischemia-induced neuronal death. ► Treatment with escitalopram increases BDNF immunoreactivity and protein levels after ischemic damage. ► Treatment with escitalopram attenuates microglia activation and oxidative stress.</P>

Astrogliosis Is a Possible Player in Preventing Delayed Neuronal Death

Jeong, Hey-Kyeong,Ji, Kyung-Min,Min, Kyoung-Jin,Choi, Insup,Choi, Dong-Joo,Jou, Ilo,Joe, Eun-Hye Korean Society for Molecular and Cellular Biology 2014 Molecules and cells Vol.37 No.4

Mitigating secondary delayed neuronal injury has been a therapeutic strategy for minimizing neurological symptoms after several types of brain injury. Interestingly, secondary neuronal loss appeared to be closely related to functional loss and/or death of astrocytes. In the brain damage induced by agonists of two glutamate receptors, N-ethyl-D-aspartic acid (NMDA) and kainic acid (KA), NMDA induced neuronal death within 3 h, but did not increase further thereafter. However, in the KA-injected brain, neuronal death was not obviously detectable even at injection sites at 3 h, but extensively increased to encompass the entire hemisphere at 7 days. Brain inflammation, a possible cause of secondary neuronal damage, showed little differences between the two models. Importantly, however, astrocyte behavior was completely different. In the NMDA-injected cortex, the loss of glial fibrillary acidic protein-expressing ($GFAP^+$) astrocytes was confined to the injection site until 7 days after the injection, and astrocytes around the damage sites showed extensive gliosis and appeared to isolate the damage sites. In contrast, in the KA-injected brain, $GFAP^+$ astrocytes, like neurons, slowly, but progressively, disappeared across the entire hemisphere. Other markers of astrocytes, including $S100{\beta}$, glutamate transporter EAAT2, the potassium channel Kir4.1 and glutamine synthase, showed patterns similar to that of GFAP in both NMDA- and KA-injected cortexes. More importantly, astrocyte disappearance and/or functional loss preceded neuronal death in the KA-injected brain. Taken together, these results suggest that loss of astrocyte support to neurons may be a critical cause of delayed neuronal death in the injured brain.