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Global proteomic analysis of brain tissues in transient ischemia brain damage in rats.

Chen JH, Kuo HC, Lee KF, Tsai TH - Int J Mol Sci (2015)

Bottom Line: It mediated the effects of SAM administration on the apoptotic and ER stress pathways.Our results demonstrate that the ischemic injury of neuronal cells increased cell cytoxicity and apoptosis, which were accompanied by sustained activation of the IRE1-alpha/TRAF2, JNK1/2, and p38 MAPK pathways.Based on these results, we also provide the molecular evidence supporting the ischemia-reperfusion-related neuronal injury.

View Article: PubMed Central - PubMed

Affiliation: Institute of Traditional Medicine, School of Medicine, National Yang-Ming University, Taipei 112, Taiwan. chenjiannhwa@yahoo.com.tw.

ABSTRACT
Ischemia-reperfusion injury resulting from arterial occlusion or hypotension in patients leads to tissue hypoxia with glucose deprivation, which causes endoplasmic reticulum (ER) stress and neuronal death. A proteomic approach was used to identify the differentially expressed proteins in the brain of rats following a global ischemic stroke. The mechanisms involved the action in apoptotic and ER stress pathways. Rats were treated with ischemia-reperfusion brain injuries by the bilateral occlusion of the common carotid artery. The cortical neuron proteins from the stroke animal model (SAM) and the control rats were separated using two-dimensional gel electrophoresis (2-DE) to purify and identify the protein profiles. Our results demonstrated that the SAM rats experienced brain cell death in the ischemic core. Fifteen proteins were expressed differentially between the SAM rats and control rats, which were assayed and validated in vivo and in vitro. Interestingly, the set of differentially expressed, down-regulated proteins included catechol O-methyltransferase (COMT) and cathepsin D (CATD), which are implicated in oxidative stress, inflammatory response and apoptosis. After an ischemic stroke, one protein spot, namely the calretinin (CALB2) protein, showed increased expression. It mediated the effects of SAM administration on the apoptotic and ER stress pathways. Our results demonstrate that the ischemic injury of neuronal cells increased cell cytoxicity and apoptosis, which were accompanied by sustained activation of the IRE1-alpha/TRAF2, JNK1/2, and p38 MAPK pathways. Proteomic analysis suggested that the differential expression of CALB2 during a global ischemic stroke could be involved in the mechanisms of ER stress-induced neuronal cell apoptosis, which occurred via IRE1-alpha/TRAF2 complex formation, with activation of JNK1/2 and p38 MAPK. Based on these results, we also provide the molecular evidence supporting the ischemia-reperfusion-related neuronal injury.

No MeSH data available.


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Schematic presentation of the signaling pathways involved in OGD-induced cells apoptosis in N2a cells. The effect of ischemic stroke on the ER stress triggering production of ROS activates IRE1-alpha/TRAF2 complex formation and phosphorylation of JNK1/2 and p38 MAPK pathways, which induces the calretinin up-regulation and increases the apoptosis cascade.
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ijms-16-11873-f007: Schematic presentation of the signaling pathways involved in OGD-induced cells apoptosis in N2a cells. The effect of ischemic stroke on the ER stress triggering production of ROS activates IRE1-alpha/TRAF2 complex formation and phosphorylation of JNK1/2 and p38 MAPK pathways, which induces the calretinin up-regulation and increases the apoptosis cascade.

Mentions: The induction of apoptosis in neuronal cells after ischemic stroke is a critical feature of oxidative stress [22]. Oxidative stress occurs when the generation of reactive oxygen species (ROS) or their products with excessive uncontrolled antioxidant protection, contributes to the neurodegenerative disorders and the pathological changes in ischemic brain injury. Ischemia reperfusion impedes BBB effects on oxygen consumption and glucose in neuronal morphology and function, including the survival and the plasticity of the neurons. These factors accumulate the peroxidative damage of particular proteins’ reactions, which are important regulators of intracellular signaling [21,22]. In this study, we demonstrated the target of stroke injury. Increased expression in CALB2, along with apoptosis initiated via the activation of JNK1/2, p38 MAPK signaling and ROS, triggers modules in OGD-treated N2a neuron cells (Figure 5, Table 2). Interestingly, CALB2, a calcium-binding or calcium-buffering protein that has been used as a distinguishing marker destined to be modified in ER, functions in maintaining calcium hemostasis and in leading neuron apoptosis injury. Among Ca2+ binding protein, calretinin is believed to play an important role in calcium homeostasis. Calretinin (CALB2) is a Ca2+ binding protein present in various populations of neurons distributed in the central and peripheral nervous systems. Previous study of deficient (−/−) mice has shown that regulation of the [Ca2+] ion plays a crucial role in information processing in the cerebellar cortex and is involved in the induction of synaptic plasticity [12]. To validate these findings, further study using CALB2 ablation is needed to determine whether there are mediated actions to induce ischemic stroke neuron injury in calretinin knock-out mice [26,27]. Many studies have shown that lower calcium can promote apoptotic injury in neurons, while ROS can target ER resident proteins, chaperones and calcium channels, leading to the release of calcium from the ER into the cytosol and ER-stress signaling to correlate with increased neuronal death [19,20,21]. In addition, we suggest that these activation effects result from a downstream gene of IRE1α/TRAF2 illustration after the OGD periods and that these effects occur in response to ER stress signaling (Figure 6). It has been shown previously that the activation of c-Jun N-terminal kinases (JNK) and p38 mitogen-activated protein kinase (p38/MAPK), also called stress-activated protein kinases, has been implicated in many cellular processes such as the neuronal death associated with cerebral ischemia [17,18]. Our results showed that OGD expression of differentially displayed CALB2 proteins had an effect on the cytotoxicity of neuron cells by activating the JNK1/2 and p38 MAPK pathway, which is preceded by the association of IRE1α/TRAF2, an induction of ROS (Figure 7).


Global proteomic analysis of brain tissues in transient ischemia brain damage in rats.

Chen JH, Kuo HC, Lee KF, Tsai TH - Int J Mol Sci (2015)

Schematic presentation of the signaling pathways involved in OGD-induced cells apoptosis in N2a cells. The effect of ischemic stroke on the ER stress triggering production of ROS activates IRE1-alpha/TRAF2 complex formation and phosphorylation of JNK1/2 and p38 MAPK pathways, which induces the calretinin up-regulation and increases the apoptosis cascade.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4490420&req=5

ijms-16-11873-f007: Schematic presentation of the signaling pathways involved in OGD-induced cells apoptosis in N2a cells. The effect of ischemic stroke on the ER stress triggering production of ROS activates IRE1-alpha/TRAF2 complex formation and phosphorylation of JNK1/2 and p38 MAPK pathways, which induces the calretinin up-regulation and increases the apoptosis cascade.
Mentions: The induction of apoptosis in neuronal cells after ischemic stroke is a critical feature of oxidative stress [22]. Oxidative stress occurs when the generation of reactive oxygen species (ROS) or their products with excessive uncontrolled antioxidant protection, contributes to the neurodegenerative disorders and the pathological changes in ischemic brain injury. Ischemia reperfusion impedes BBB effects on oxygen consumption and glucose in neuronal morphology and function, including the survival and the plasticity of the neurons. These factors accumulate the peroxidative damage of particular proteins’ reactions, which are important regulators of intracellular signaling [21,22]. In this study, we demonstrated the target of stroke injury. Increased expression in CALB2, along with apoptosis initiated via the activation of JNK1/2, p38 MAPK signaling and ROS, triggers modules in OGD-treated N2a neuron cells (Figure 5, Table 2). Interestingly, CALB2, a calcium-binding or calcium-buffering protein that has been used as a distinguishing marker destined to be modified in ER, functions in maintaining calcium hemostasis and in leading neuron apoptosis injury. Among Ca2+ binding protein, calretinin is believed to play an important role in calcium homeostasis. Calretinin (CALB2) is a Ca2+ binding protein present in various populations of neurons distributed in the central and peripheral nervous systems. Previous study of deficient (−/−) mice has shown that regulation of the [Ca2+] ion plays a crucial role in information processing in the cerebellar cortex and is involved in the induction of synaptic plasticity [12]. To validate these findings, further study using CALB2 ablation is needed to determine whether there are mediated actions to induce ischemic stroke neuron injury in calretinin knock-out mice [26,27]. Many studies have shown that lower calcium can promote apoptotic injury in neurons, while ROS can target ER resident proteins, chaperones and calcium channels, leading to the release of calcium from the ER into the cytosol and ER-stress signaling to correlate with increased neuronal death [19,20,21]. In addition, we suggest that these activation effects result from a downstream gene of IRE1α/TRAF2 illustration after the OGD periods and that these effects occur in response to ER stress signaling (Figure 6). It has been shown previously that the activation of c-Jun N-terminal kinases (JNK) and p38 mitogen-activated protein kinase (p38/MAPK), also called stress-activated protein kinases, has been implicated in many cellular processes such as the neuronal death associated with cerebral ischemia [17,18]. Our results showed that OGD expression of differentially displayed CALB2 proteins had an effect on the cytotoxicity of neuron cells by activating the JNK1/2 and p38 MAPK pathway, which is preceded by the association of IRE1α/TRAF2, an induction of ROS (Figure 7).

Bottom Line: It mediated the effects of SAM administration on the apoptotic and ER stress pathways.Our results demonstrate that the ischemic injury of neuronal cells increased cell cytoxicity and apoptosis, which were accompanied by sustained activation of the IRE1-alpha/TRAF2, JNK1/2, and p38 MAPK pathways.Based on these results, we also provide the molecular evidence supporting the ischemia-reperfusion-related neuronal injury.

View Article: PubMed Central - PubMed

Affiliation: Institute of Traditional Medicine, School of Medicine, National Yang-Ming University, Taipei 112, Taiwan. chenjiannhwa@yahoo.com.tw.

ABSTRACT
Ischemia-reperfusion injury resulting from arterial occlusion or hypotension in patients leads to tissue hypoxia with glucose deprivation, which causes endoplasmic reticulum (ER) stress and neuronal death. A proteomic approach was used to identify the differentially expressed proteins in the brain of rats following a global ischemic stroke. The mechanisms involved the action in apoptotic and ER stress pathways. Rats were treated with ischemia-reperfusion brain injuries by the bilateral occlusion of the common carotid artery. The cortical neuron proteins from the stroke animal model (SAM) and the control rats were separated using two-dimensional gel electrophoresis (2-DE) to purify and identify the protein profiles. Our results demonstrated that the SAM rats experienced brain cell death in the ischemic core. Fifteen proteins were expressed differentially between the SAM rats and control rats, which were assayed and validated in vivo and in vitro. Interestingly, the set of differentially expressed, down-regulated proteins included catechol O-methyltransferase (COMT) and cathepsin D (CATD), which are implicated in oxidative stress, inflammatory response and apoptosis. After an ischemic stroke, one protein spot, namely the calretinin (CALB2) protein, showed increased expression. It mediated the effects of SAM administration on the apoptotic and ER stress pathways. Our results demonstrate that the ischemic injury of neuronal cells increased cell cytoxicity and apoptosis, which were accompanied by sustained activation of the IRE1-alpha/TRAF2, JNK1/2, and p38 MAPK pathways. Proteomic analysis suggested that the differential expression of CALB2 during a global ischemic stroke could be involved in the mechanisms of ER stress-induced neuronal cell apoptosis, which occurred via IRE1-alpha/TRAF2 complex formation, with activation of JNK1/2 and p38 MAPK. Based on these results, we also provide the molecular evidence supporting the ischemia-reperfusion-related neuronal injury.

No MeSH data available.


Related in: MedlinePlus