Hck Promotes Neuronal Apoptosis Following Intracerebral Hemorrhage

The hematopoietic cell kinase (Hck) is a member of the Src family protein kinases which regulates many signal transduction pathways including cell growth, proliferation, differentiation, migration, and apoptosis. However, the expression and function of Hck after intracerebral hemorrhage (ICH) are unknown. Western blot, immunohistochemistry, and immunofluorescence showed that Hck was obviously up-regulation in neurons adjacent to the hematoma after ICH. In addition, the temporary raise of Hck expression was paralleled with the expression of p53, Bax, and active caspase-3, suggesting that Hck was involved in neuronal apoptosis. Hck siRNA dramatically decrease hemin-induced expression of p53, Bax, and active caspase-3 as well as the amount of apoptotic SH-SY5Y cells in vitro. Furthermore, Hck interacted with p53. Hence, Hck might promote neuronal apoptosis via p53 signaling pathway after ICH.     

MEKK1 Associated with Neuronal Apoptosis Following Intracerebral Hemorrhage

The JNKs have been implicated in a variety of biological functions in mammalian cells, including apoptosis and the responses to stress. However, the physiological role of these pathways in the intracerebral hemorrhage (ICH) has not been fully elucidated. In this study, we identified a MAPK kinase kinase (MAPKKK), MEKK1, may be involved in neuronal apoptosis in the processes of ICH through the activation of JNKs. From the results of western blot, immunohistochemistry and immunofluorescence, we obtained a significant up-regulation of MEKK1 in neurons adjacent to the hematoma following ICH. Increasing MEKK1 level was found to be accompanied with the up-regulation of p-JNK 3, p53, and c-jun. Besides, MEKK1 co-localized well with p-JNK in neurons, indicating its potential role in neuronal apoptosis. What’s more, our in vitro study, using MEKK1 siRNA interference in PC12 cells, further confirmed that MEKK1 might exert its pro-apoptotic function on neuronal apoptosis through extrinsic pathway. Thus, MEKK1 may play a role in promoting the brain damage following ICH.     

Retraction Note to: Up-Regulation of KPNB1 Involves in Neuronal Apoptosis Following Intracerebral Hemorrhage in Adult Rats

Neurochemical Research -     

Up-Regulation of Interferon Regulatory Factor 3 Involves in Neuronal Apoptosis After Intracerebral Hemorrhage in Adult Rats

Interferon regulatory factor 3 (IRF3) is a member of IRF family which plays a significant role in the innate immune response, apoptosis, and oncogenesis. Mounting evidence has demonstrated that IRF3 was involved in central nervous system disease such as cerebral ischemic injury through promoting neuronal apoptosis. However, it remains unclear about the underlying mechanisms of IRF3 upon neuronal apoptosis following intracerebral hemorrhage (ICH). In the present study, we established an adult rat ICH model by injecting autologous whole blood into the right basal ganglia and evaluated their neurological deficits by behavioral tests. IRF3 protein level was up-regulated adjacent to the hematoma following ICH when compared with the sham brain cortex by western blot and immunohistochemistry. Immunofluorescent staining indicated IRF3 was mainly localized in neurons, a few in astrocytes. In addition, we also detected that IRF3 co-localized with active caspase-3 which is a neuronal apoptosis marker. Furthermore, in vitro study, knocking down IRF3 by using IRF3 interference in primary cortical neurons reduced the expression of active caspase-3 and Bax while increased Bcl-2. In conclusion, we speculated that IRF3 might exert pro-apoptotic function in neurons after ICH.     

IDH1 Associated with Neuronal Apoptosis in Adult Rats Brain Following Intracerebral Hemorrhage

Isocitrate dehydrogenase 1 (IDH1), one member of the IDH family can convert isocitrate to α-ketoglutarate (α-KG) via oxidative decarboxylation. IDH1 and IDH2 mutations have been identified in multiple tumor types and the mutations confer neomorphic activity in the mutant protein, resulting in the conversion of α-KG to the oncometabolite, D-2-hydroxyglutarate (2-HG). The subsequent accumulation of 2-HG results in epigenetic dysregulation via inhibition of α-KG-dependent histone and DNA demethylase. And the glutamate levels are reduced in IDH mutant cells compared to wild-type. We have known that diffuse gliomas contain a high frequency of mutations in the IDH1 gene. However, the expression of IDH1 and its roles in Intracranial hemorrhage (ICH) remain largely unknown. We observed increased expression of IDH1 in neurons after intracerebral hemorrhage. Up-regulation of IDH1 was found to be accompanied by the increased expression of active caspase-3 and pro-apoptotic Bcl-2-associated X protein and decreased expression of anti-apoptotic protein B cell lymphoma-2 in vivo and vitro studies. So we hypothesized that IDH1 was involved in the regulation of neuronal apoptosis. The present research for the first time detected the expression and variation of IDH1 surrounding the hematoma, and all data proved the involvement of IDH1 in neuronal apoptosis following ICH.     

EP3, Prostaglandin E2 Receptor Subtype 3, Associated with Neuronal Apoptosis Following Intracerebral Hemorrhage

EP3 is prostaglandin E2 receptor subtype 3 and mediates the activation of several signaling pathways, changing in cAMP levels, calcium mobilization, and activation of phospholipase C. Previous studies demonstrated a direct role for EP3 in various neurodegenerative disorders, such as stroke and Alzheimer disease. However, the distribution and function of EP3 in ICH diseases remain unknown. Here, we demonstrate that EP3 may be involved in neuronal apoptosis in the processes of intracerebral hemorrhage (ICH). From the results of Western blot and immunohistochemistry, we obtained a significant up-regulation of EP3 in neurons adjacent to the hematoma following ICH. Up-regulation of EP3 was found to be accompanied by the increased expression of active caspase-3 and pro-apoptotic Bcl-2-associated X protein (Bax) and decreased expression of anti-apoptotic protein B cell lymphoma-2 (Bcl-2) in vivo and vitro studies. Furthermore, the expression of these three proteins reduced active caspase-3 and Bax expression, while increased Bcl-2 were changed after knocking down EP3 by RNA interference in PC12 cells, further confirmed that EP3 might exert its pro-apoptotic function on neuronal apoptosis. Thus, EP3 may play a role in promoting the neuronal apoptosis following ICH.     

Increased Expression of Ubiquitin-Specific Protease 4 Participates in Neuronal Apoptosis After Intracerebral Hemorrhage in Adult Rats

Ubiquitinating enzymes catalyze protein ubiquitination, a reversible process countered by deubiquitinating enzyme (DUB) action. Ubiquitin-specific protease 4 (USP4) is a member of the ubiquitin-specific protease (USP) family of DUBs that has a role in spliceosome regulation. In the present study, we demonstrated that USP4 may be involved in neuronal apoptosis in the processes of intracerebral hemorrhage (ICH). We obtained a significant up-regulation of USP4 in neurons adjacent to the hematoma following ICH by the results of Western blot, immunohistochemistry, and immunofluorescence. Increasing USP4 level was found to be accompanied by the up-regulation of active caspase-3, γH2AX, Bax, and decreased expression of Bcl-2. In addition, USP4 co-localized well with γH2AX in the nucleus in the ICH model and hemin-induced apoptosis model. Moreover, in vitro study, knocking down USP4 by USP4-specific siRNA in PC12 cells reduced active caspase-3 expression. All these results above suggested that USP4 may be involved in neuronal apoptosis after ICH.     

Up-Regulation of TAB3 Is Involved in Neuronal Apoptosis After Intracerebral Hemorrhage

Human transforming growth factor β-activated kinase (TAK1)-binding protein 3 (TAB3) is a regulator of NF-κB which has been mainly found in a variety of cancers. While TAB3 is highly expressed in brain tissue, little is known about the function of TAB3 in central nervous system. Our group established an animal ICH model with autologous whole blood injected into brain, and also a cell ICH model with hemin stimulation. Our Western blot result showed up-regulation of TAB3 during neuronal apoptosis in the model of intracerebral hemorrhage (ICH), which was also approved by immunofluorescence and immunohistochemistry result. Besides, increasing TAB3 level was accompanied by the increased expression of active-caspase-3, active-caspase-8, and decreased expression of Bcl-2. Furthermore, in in vitro study, the level of neuronal apoptosis was decreased by applying TAB3- RNA interference in PC12 cells. All the results above suggested that TAB3 probably participates in the process of neuronal apoptosis following ICH.     

Up-Regulation of Podoplanin Involves in Neuronal Apoptosis in LPS-Induced Neuroinflammation

Podoplanin (PDPN) is a mucin-type transmembrane sialoglycoprotein expressed in multiple tissues in adult animals, including the brain, lungs, kidney, and lymphoid organs. Studies of this molecule have demonstrated its great importance in tumor metastasis, platelet aggregation, and lymphatic vessel formation. However, information regarding its regulation and possible function in the central nervous system is still limited. In this study, we performed a neuroinflammatory model by lipopolysaccharide (LPS) lateral ventral injection in adult rats and detected increased expression of PDPN in the brain cortex. Immunofluorescence indicated that PDPN was located in the neurons, but not astrocytes. Moreover, there was a concomitant up-regulation of active caspase-3, cyclin D1, and CDK4 in vivo and vitro studies. In addition, the expression of these three proteins in cortical primary neurons was decreased after knocking down PDPN by siRNA. Collectively, all these results suggested that the up-regulation of PDPN might be involved in neuronal apoptosis in neuroinflammation after LPS injection.     

Upregulated Expression of SSTR1 is Involved in Neuronal Apoptosis and is Coupled to the Reduction of bcl-2 Following Intracerebral Hemorrhage in Adult Rats

Somatostatins are peptide hormones that regulate diverse cellular processes, such as neurotransmission, cell proliferation, apoptosis, and endocrine signaling as well as inhibiting the release of many hormones and other secretory proteins. SSTR1 is a member of the superfamily of somatostatin receptors possessing seven-transmembrane segments. Aberrant expression of SSTR1 has been implicated in several human diseases, including pseudotumor cerebri, and oncogenic osteomalacia. In this study, we investigated a potential role of SSTR1 in the regulation of neuronal apoptosis in the course of intracerebral hemorrhage (ICH). A rat ICH model in the caudate putamen was established and subjected to behavioral tests. Western blot and immunohistochemistry indicated a remarkable up-regulation of SSTR1 expression surrounding the hematoma after ICH. Double-labeled immunofluorescence showed that SSTR1 was mostly co-localized with neurons, and was rarely distributed in activated astrocytes and microglia. Additionally, SSTR1 co-localized with active-caspase-3 and bcl-2 around the hematoma. The expression of active-caspase-3 was parallel with that of SSTR1 in a time-dependent manner. In addition, SSTR1 knockdown specifically resulted in reduced neuronal apoptosis in PC12 cells. All our findings suggested that up-regulated SSTR1 contributed to neuronal apoptosis after ICH, which was accompanied with reduced expression of bcl-2.     

Nemo-like Kinase (NLK) Involves in Neuronal Apoptosis after Traumatic Brain Injury

Traumatic brain injury (TBI) consists of two phases: an immediate phase in which damage is caused as a direct result of the mechanical impact: and a late phase of altered biochemical events that results in delayed tissue damage and is therefore amenable to therapeutic treatment. Because the molecular mechanisms of delayed post-traumatic neuronal cell death are still poorly understood, we investigated whether nemo-like kinase (NLK), an evolutionarily conserved serine/threonine kinase involved in neuronal apoptosis following TBI. In the model of TBI, western blot analysis, double immunofluorescent staining and immunohistochemistry were used to analyze the role of NLK in the process. The results showed a significant down-regulation of NLK and a concomitant up-regulation of caspase-3 during the early stage of TBI. In the model of glutamate inducing PC12 apoptosis, we analyzed the effect of over-expression of NLK on the neuronal cell line PC12 apoptosis by cck-8, western blot and TUNEL assays. Together with previous reports. We hypothesize NLK was related to the down-regulation of caspase-3 expression after TBI, and such an event may be associated with neuronal apoptosis.     

铁离子在脑出血后继发性脑损害中的作用

脑出血(intracerebral hemorrhage,ICH)是一种高致残率和高死亡率的急症.研究表明凝血酶的形成,红血球的溶解以及铁离子的毒性在脑出血的病程中都起作用,尤其是铁离子在其后的继发性脑损害中扮演重要角色.铁离子在血肿处的高浓度促使了急性脑水肿的形成,以及迟发性脑萎缩的发生,而铁螯合荆能够减轻其损伤.本文就脑出血后有关铁离子的脑损伤机制进行综述.     

Up-regulation of TRAF2 Suppresses Neuronal Apoptosis after Rat Spinal Cord Injury

Tumor necrosis factor receptor-associated factor 2 (TRAF2) for signal transduction of the cell death receptor is well established. However, the role of TRAF2 in spinal cord injury (SCI) remains unclear. In this study, we detected the dynamic change patterns of TRAF2 expression using an acute spinal cord contusion (SCC) model in adult rats. Western blot analysis and immunohistochemistry identified significant upregulation of TRAF2 after SCI. Double-immunofluorescent staining demonstrated that the upregulated TRAF2 was found predominantly in neurons. Moreover, colocalization of TRAF2 with active caspase-3/-8 was detected in NeuN-positive cells. In vitro, we analyzed the association of TRAF2 with active caspase-3/8 on PC12 cells by western blot analysis, which paralleled the in vivo data. Knockdown ofTRAF2 with siRNA demonstrated its probable anti-apoptotic role in the process of neuronal apoptosis after SCI. To summarize, we have revealed for the first time the temporal and spatial expression profile of TRAF2 in SCI. Our data suggest that upregulation of TRAF2 triggered by trauma plays an important role in suppressing neuronal apoptosis after SCI.     

Gabapentin Alleviates Brain Injury in Intracerebral Hemorrhage Through Suppressing Neuroinflammation and Apoptosis

Neurochemical Research - Neuroinflammation plays an important role in brain tissue injury during intracerebral hemorrhage. Gabapentin can reduce inflammation and oxidative stress through inhibiting...     

Up-regulation of MCM3 Relates to Neuronal Apoptosis After Traumatic Brain Injury in Adult Rats

Minichromosome maintenance complex component 3, one of the minichromosome maintenance proteins, functions as a part of pre-replication complex to initiate DNA replication in eukaryotes. Minichromosome maintenance complex component 3 (MCM3) was mainly implied in cell proliferation and tumorigenesis. In addition, MCM3 might play an important role in neuronal apoptosis. However, the functions of MCM3 in central nervous system are still with limited acquaintance. In this study, we performed a traumatic brain injury (TBI) model in adult rats. Western blot and immunohistochemistry staining showed up-regulation of MCM3 in the peritrauma brain cortex. The expression patterns of active caspase-3 and Bax, Bcl-2 were parallel with that of MCM3. Immunofluorescent staining and terminal deoxynucleotidyl transferase-mediated biotinylated-dUTP nick-end labeling suggested that MCM3 was involved in neuronal apoptosis. In conclusion, our data indicated that MCM3 might play an important role in neuronal apoptosis following TBI. Further understanding of these insights could serve as the basis for broadening the therapeutic scope against TBI.