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Chen J, Huang F, Fang X, Li S, Liang Y. Silencing TLR4 using an ultrasound-targeted microbubble destruction-based shRNA system reduces ischemia-induced seizures in hyperglycemic rats. Open Life Sci 2022; 17:1689-1697. [PMID: 36619717 PMCID: PMC9795576 DOI: 10.1515/biol-2022-0526] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 09/28/2022] [Accepted: 10/12/2022] [Indexed: 12/28/2022] Open
Abstract
The toll-like receptor 4 (TLR4) pathway is involved in seizures. We investigated whether ultrasound-targeted microbubble destruction (UTMD)-mediated delivery of short hairpin RNA (shRNA) targeting the TLR4 gene (shRNA-TLR4) can reduce ischemia-induced seizures in rats with hyperglycemia. A total of 100 male Wistar rats were randomly assigned to five groups: (1) Sham; (2) normal saline (NS); (3) shRNA-TLR4, where rats were injected with shRNA-TLR4; (4) shRNA-TLR4 + US, where rats were injected with shRNA-TLR4 followed by ultrasound (US) irradiation; and (5) shRNA-TLR4 + microbubbles (MBs) + US, where rats were injected with shRNA-TLR4 mixed with MBs followed by US irradiation. Western blot and immunohistochemical staining were used to measure TLR4-positive cells. Half of the rats in the NS group developed tonic-clonic seizures, and TLR4 expression in the CA3 region of the hippocampus was increased in these rats. In addition, the NS group showed an increased number of TLR4-positive cells compared with the Sham group, while there was a decreased number of TLR4-positive cells in the shRNA, shRNA + US, and shRNA + MBs + US groups. Our findings indicate that the TLR4 pathway is involved in the pathogenesis of ischemia-induced seizures in hyperglycemic rats and that UTMD technology may be a promising strategy to treat brain diseases.
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Affiliation(s)
- Jia Chen
- Department of Neurology, The Third Affiliated Hospital of Guangzhou Medical University, 63 Duobao Road, Liwan District, Guangzhou, 510150, China
| | - Fami Huang
- Department of Intensive Care Unit, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan, 511500, China
| | - Xiaobo Fang
- Department of Neurology, The Third Affiliated Hospital of Guangzhou Medical University, 63 Duobao Road, Liwan District, Guangzhou, 510150, China
| | - Siying Li
- Department of Neurology, The Third Affiliated Hospital of Guangzhou Medical University, 63 Duobao Road, Liwan District, Guangzhou, 510150, China
| | - Yanling Liang
- Department of Neurology, The Third Affiliated Hospital of Guangzhou Medical University, 63 Duobao Road, Liwan District, Guangzhou, 510150, China,Key Laboratory for Major Obstetric Diseases of Guangdong Province, Guangzhou, 510150, China
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Quercetin alleviates neonatal hypoxic-ischemic brain injury by inhibiting microglia-derived oxidative stress and TLR4-mediated inflammation. Inflamm Res 2020; 69:1201-1213. [PMID: 32944799 DOI: 10.1007/s00011-020-01402-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 09/10/2020] [Accepted: 09/14/2020] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVE AND DESIGN Microglia stimulated by oxygen glucose deprivation (OGD) were treated with quercetin to investigate the effect on oxidative stress and the inflammatory response and to explore whether toll-like receptor 4 (TLR4) signaling was involved. In addition, the effect of quercetin on the neurological functions of neonatal mice with hypoxic-ischemic brain injury (HIBI) was examined. MATERIALS AND SUBJECTS Mouse BV2 microglial cells and postnatal day 7 neonatal mice were used. TREATMENT A predetermined concentration of quercetin was used in cell experiments. Quercetin was injected i.p. (50 mg/kg) at three time points after HI insult: 0, 24, and 48 h. METHODS Cell viability assay, Western blotting, qRT-RCR, ELISA, HIBI model construction and behavioral tests. RESULTS This study first showed that quercetin protected BV2 cells from OGD-induced damage and reversed the changes in microglial oxidative stress-related molecules. Second, quercetin inhibited OGD-induced expression of inflammatory factors in BV2 cells and suppressed TLR4/MyD88/NF-κB signaling. Finally, quercetin was disclosed to be effective in mitigating cerebral infarct volume and cognitive and motor function deficits in HIBI mice. CONCLUSION These results suggest that the neuroprotective effect of quercetin in HIBI mice is partially due to the inhibition of oxidative stress and TLR4-mediated inflammatory responses in activated microglia.
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Le K, Wu S, Chibaatar E, Ali AI, Guo Y. Alarmin HMGB1 Plays a Detrimental Role in Hippocampal Dysfunction Caused by Hypoxia-Ischemia Insult in Neonatal Mice: Evidence from the Application of the HMGB1 Inhibitor Glycyrrhizin. ACS Chem Neurosci 2020; 11:979-993. [PMID: 32073822 DOI: 10.1021/acschemneuro.0c00084] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Hippocampal dysfunction related to cognitive impairment and emotional disorders in young children and adolescents caused by neonatal hypoxic-ischemic brain injury (HIBI) has attracted increasing attention in recent years. Crosstalk between the nervous and immune systems organized by hypoxia-ischemia (HI) insult may contribute to hippocampal dysfunction after HIBI. Extracellular HMGB1 functions as a damage-associated molecular pattern to instigate and amplify inflammatory responses, but whether this molecule is correlated with hippocampal dysfunction after HIBI is largely unknown. Therefore, this study examined hippocampal function after HMGB1 inhibition in an experimental HIBI model to verify the hypothesis that HMGB1 is a key mediator of hippocampal neuropathology in neonatal HIBI. By administering different doses of the HMGB1-specific inhibitor glycyrrhizin (GLY), we first found that GLY reversed the HI insult-induced loss of neurons and myelin in the hippocampal region and neurobehavioral impairments, partially in a dose-dependent manner, and based on this, we determined the optimal drug concentration to be 50 mg/kg. Subsequent analysis found that this neuroprotective effect was achieved through the inhibition of HMGB1 expression and nucleocytoplasmic translocation, a reduction in the abnormal expression of proteins associated with the downstream signaling pathway of HMGB1, a decrease in the inflammatory response, the suppression of increases in microglia/astrocytes, and the inhibition of hippocampal cell apoptosis. Collectively, our discoveries contribute to the rising appreciation of the role of HMGB1 in the neuropathology of hippocampal dysfunction and related behavioral outcomes following HIBI.
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Affiliation(s)
- Kai Le
- Department of Neurology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu Province 210009, China
- School of Medicine, Southeast University, Nanjing, Jiangsu Province 210009, China
| | - Shanshan Wu
- Department of Neurology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu Province 210009, China
- School of Medicine, Southeast University, Nanjing, Jiangsu Province 210009, China
| | - Enkhmurun Chibaatar
- Department of Neurology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu Province 210009, China
- School of Medicine, Southeast University, Nanjing, Jiangsu Province 210009, China
| | - Abdoulaye Idriss Ali
- Department of Neurology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu Province 210009, China
- School of Medicine, Southeast University, Nanjing, Jiangsu Province 210009, China
| | - Yijing Guo
- Department of Neurology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu Province 210009, China
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4
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Deng Y, Liu K, Pan Y, Ren J, Shang J, Chen L, Liu H. TLR2 antagonism attenuates the hippocampal neuronal damage in a murine model of sleep apnea via inhibiting neuroinflammation and oxidative stress. Sleep Breath 2020; 24:1613-1621. [PMID: 32170671 DOI: 10.1007/s11325-020-02030-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 01/28/2020] [Accepted: 02/05/2020] [Indexed: 12/22/2022]
Abstract
BACKGROUND Obstructive sleep apnea (OSA) in humans chronically promotes the neuronal damage in the hippocampus. Toll-like receptor 2 (TLR2) is pivotal for the development of numerous hippocampal diseases. Chronic intermittent hypoxia (CIH) is a prominent feature of OSA. Here in our study, the effects of TLR2 antagonism on the neural damage elicited by CIH were examined. METHODS Ortho-vanillin (O-vanillin) is an inhibitor of TLR2. Adult male mice were subjected to 8 h of intermittent hypoxia per day with or without O-vanillin for 28 days. Neuronal damage, the number of microglia, the interaction of TLR2 with its adapter protein myeloid differentiation factor 88 (MYD88), the expressions of inflammatory cytokines, and the oxidative stress were observed. RESULTS O-vanillin inhibited the increased interaction of TLR2 and MyD88, the activation of NFκB, the aggregation of microglia, the overexpression of proinflammatory agents, the elevation of oxidative stress, and hippocampal neuron cell apoptosis induced by CIH. CONCLUSIONS Our experiments indicate that TLR2 antagonism may alleviate the hippocampal neuronal damage caused by CIH via inhibiting neuroinflammation and oxidative stress.
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Affiliation(s)
- Yan Deng
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Huazhong University of Science and Technology, 1095 Jiefang Ave, Wuhan, 430030, Hubei, China
| | - Kui Liu
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Huazhong University of Science and Technology, 1095 Jiefang Ave, Wuhan, 430030, Hubei, China
| | - Yueying Pan
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Huazhong University of Science and Technology, 1095 Jiefang Ave, Wuhan, 430030, Hubei, China
| | - Jie Ren
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Huazhong University of Science and Technology, 1095 Jiefang Ave, Wuhan, 430030, Hubei, China
| | - Jin Shang
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Huazhong University of Science and Technology, 1095 Jiefang Ave, Wuhan, 430030, Hubei, China
| | - Lei Chen
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Huazhong University of Science and Technology, 1095 Jiefang Ave, Wuhan, 430030, Hubei, China
| | - Huiguo Liu
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Huazhong University of Science and Technology, 1095 Jiefang Ave, Wuhan, 430030, Hubei, China.
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Li W, Yu Y, Li D, Xu N, Fang J, Sun Y, Xu M, Wang X, Han X, Zhang X, Lv C, Han F. TLR2 deficiency attenuated chronic intermittent hypoxia-induced neurocognitive deficits. Int Immunopharmacol 2020; 81:106284. [PMID: 32058931 DOI: 10.1016/j.intimp.2020.106284] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/22/2020] [Accepted: 02/02/2020] [Indexed: 12/17/2022]
Abstract
Chronic intermittent hypoxia (CIH) is the main symptom of obstructive sleep apnea syndrome (OSAS) and causes neural damage and cognitive deficits via neuroinflammation. Toll-like receptors (TLRs), especially TLR2, play an important role in neuroinflammation. However, the mechanisms by which TLR2 participates in CIH-induced cognitive deficits remain unclear. In this study, wild-type (WT) and TLR2 knock out (KO) mice were exposed to CIH for 8 weeks, and their social novelty discrimination, spatial learning and memory were severely compromised. Additionally, seriously damaged neurons and abnormally activated glia were observed in the CA1 and dentate gyrus (DG) areas of the hippocampus. Mechanistically, knocking out the TLR2 gene significantly alleviated these pathological changes and improved the behavioral performance. Together, these findings demonstrate that the TLR2-MyD88 signaling pathway might play an important role in CIH-induced cognitive deficits.
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Affiliation(s)
- Wanting Li
- Binzhou Medical University, 346 Guanhai Road, YanTai 264003, China
| | - Yan Yu
- Binzhou Medical University, 346 Guanhai Road, YanTai 264003, China.
| | - Dongze Li
- Binzhou Medical University, 346 Guanhai Road, YanTai 264003, China
| | - Na Xu
- Binzhou Medical University, 346 Guanhai Road, YanTai 264003, China
| | - Jidong Fang
- Binzhou Medical University, 346 Guanhai Road, YanTai 264003, China
| | - Yeying Sun
- Binzhou Medical University, 346 Guanhai Road, YanTai 264003, China
| | - Maolei Xu
- Binzhou Medical University, 346 Guanhai Road, YanTai 264003, China
| | - Xi Wang
- Yantai Affiliated Hospital of Binzhou Medical University, 717 Jinbu Street, YanTai 264199, China
| | - Xin Han
- Binzhou Medical University, 346 Guanhai Road, YanTai 264003, China
| | - Xiuli Zhang
- Binzhou Medical University, 346 Guanhai Road, YanTai 264003, China
| | - Changjun Lv
- Binzhou Medical University, 346 Guanhai Road, YanTai 264003, China.
| | - Fang Han
- Binzhou Medical University, 346 Guanhai Road, YanTai 264003, China.
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6
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Le K, Chibaatar Daliv E, Wu S, Qian F, Ali AI, Yu D, Guo Y. SIRT1-regulated HMGB1 release is partially involved in TLR4 signal transduction: A possible anti-neuroinflammatory mechanism of resveratrol in neonatal hypoxic-ischemic brain injury. Int Immunopharmacol 2019; 75:105779. [PMID: 31362164 DOI: 10.1016/j.intimp.2019.105779] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/22/2019] [Accepted: 07/23/2019] [Indexed: 12/26/2022]
Abstract
Neonatal hypoxic-ischemic brain injury (HIBI) is a knotty disease that lacks appropriate treatment. Inflammation is an important contributor to brain damage, and microglia are responsible for eliciting early and pronounced inflammatory reactions in the immature brain after hypoxic-ischemic (HI) insult. Acetylated HMGB1 can be released from immune cells into the extracellular space, where it acts as a danger-associated molecular pattern molecule to activate TLR4 signalling-mediated inflammatory responses. Resveratrol has neuroprotective and anti-inflammatory effects against HIBI, but whether these effects involve the regulation of the TLR4 signalling pathway and whether HMGB1 participates in this process is still unclear. We investigated the anti-inflammatory effects of resveratrol in HIBI and the molecular mechanisms potentially involved in the effect. The in vivo and in vitro results indicated that the level of cytoplasmic HMGB1 in microglia increased after insult and that treating experimental animals or mouse BV2 microglial cells with resveratrol attenuated HI insult-induced neuroinflammation, which was characterized by improved behavioural defects, reduced microglial activation and TLR4/MyD88/NF-κB signalling, and attenuated primary neuronal damage; this was accompanied by the inhibition of HMGB1 nucleoplasmic transfer and extracellular release. EX527 pretreatment reversed these effects. In addition, co-immunoprecipitation confirmed that SIRT1 was directly involved in the HMGB1 acetylation process in BV2 cells after oxygen glucose deprivation. These data demonstrate that resveratrol plays a neuroprotective role in neonatal HIBI by activating SIRT1 to inhibit HMGB1/TLR4/MyD88/NF-κB signalling and subsequent neuroinflammatory responses.
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Affiliation(s)
- Kai Le
- Department of Neurology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu Province 210009, China; School of Medicine, Southeast University, Nanjing, Jiangsu Province 210009, China
| | - Enkhmurun Chibaatar Daliv
- Department of Neurology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu Province 210009, China; School of Medicine, Southeast University, Nanjing, Jiangsu Province 210009, China
| | - Shanshan Wu
- Department of Neurology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu Province 210009, China; School of Medicine, Southeast University, Nanjing, Jiangsu Province 210009, China
| | - Fangyuan Qian
- Department of Neurology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu Province 210009, China; School of Medicine, Southeast University, Nanjing, Jiangsu Province 210009, China
| | - Abdoulaye Idriss Ali
- Department of Neurology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu Province 210009, China; School of Medicine, Southeast University, Nanjing, Jiangsu Province 210009, China
| | - Dafan Yu
- Department of Neurology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu Province 210009, China; School of Medicine, Southeast University, Nanjing, Jiangsu Province 210009, China
| | - Yijing Guo
- Department of Neurology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu Province 210009, China.
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7
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Ko HR, Ahn SY, Chang YS, Hwang I, Yun T, Sung DK, Sung SI, Park WS, Ahn JY. Human UCB-MSCs treatment upon intraventricular hemorrhage contributes to attenuate hippocampal neuron loss and circuit damage through BDNF-CREB signaling. Stem Cell Res Ther 2018; 9:326. [PMID: 30463591 PMCID: PMC6249960 DOI: 10.1186/s13287-018-1052-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 10/02/2018] [Accepted: 10/17/2018] [Indexed: 12/15/2022] Open
Abstract
Background Human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) have been shown to prevent brain damage and improve neurocognition following intraventricular hemorrhage (IVH). However, the molecular mechanisms underlying the effects of hUCB-MSCs are still elusive. Thus, as the hippocampus is essential for learning, memory, and cognitive functions and is intimately involved in the ventricular system, making it a potential site of IVH-induced injury, we determined the molecular basis of the effects of hUCB-derived MSCs on hippocampal neurogenesis and the recovery of hippocampal neural circuits after IVH in a rodent model. Methods We inflicted severe IVH injury on postnatal day 4 (P4) in rats. After confirmation of successful induction of IVH using MRI (P5), intracerebroventricular administration of MSCs (ICV-MSC) was performed at 2 days post-injury (P6). For hippocampal synaptic determination, a rat entorhinal-hippocampus (EH) organotypic slice co-culture (OSC) was performed using day 3 post-IVH brains (P7) with or without ICV-MSCs. A similar strategy of experiments was applied to those rats receiving hUCB-MSC transfected with BDNF-Si-RNA for knockdown of BDNF or scrambled siRNA controls after IVH. The molecular mechanism of the MSCs effects on neurogenesis and the attenuation of neuron death was determined by evaluation of BDNF-TrkB-Akt-CREB signaling axis. Results We showed that treatment with hUCB-MSCs attenuated neuronal loss and promoted neurogenesis in the hippocampus, an area highly vulnerable to IVH-induced brain injury. hUCB-MSCs activate BDNF-TrkB receptor signaling, eliciting intracellular activation of Akt and/or Erk and subsequent phosphorylation of CREB, which is responsible for promoting rat BDNF transcription. In addition to the beneficial effects of neuroprotection and neurogenesis, hUCB-MSCs also contribute to the restoration of impaired synaptic circuits in the hippocampus and improve neurocognitive functions in IVH-injured neonatal rat through BDNF-TrkB-CREB signaling axis activation. Conclusions Our data suggest that hUCB-MSCs possess therapeutic potential for treating neuronal loss and neurocognitive dysfunction in IVH through the activation of intracellular TrkB-CREB signaling that is invoked by hUCB-MSC-secreted BDNF. Electronic supplementary material The online version of this article (10.1186/s13287-018-1052-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hyo Rim Ko
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, 2066, Seobu-ro, Jangan-gu, Suwon, 16419, South Korea.,Single Cell Network Research Center, Sungkyunkwan University School of Medicine, Suwon, 16419, South Korea
| | - So Yoon Ahn
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwonro, Gangnam-gu, Seoul, 06351, South Korea.,Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, South Korea.,Stem Cell and Regenerative Medicine Institute, Samsung Medical Center, Seoul, 06351, South Korea
| | - Yun Sil Chang
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwonro, Gangnam-gu, Seoul, 06351, South Korea.,Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, South Korea.,Stem Cell and Regenerative Medicine Institute, Samsung Medical Center, Seoul, 06351, South Korea
| | - Inwoo Hwang
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, 2066, Seobu-ro, Jangan-gu, Suwon, 16419, South Korea.,Single Cell Network Research Center, Sungkyunkwan University School of Medicine, Suwon, 16419, South Korea
| | - Taegwan Yun
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, 2066, Seobu-ro, Jangan-gu, Suwon, 16419, South Korea.,Single Cell Network Research Center, Sungkyunkwan University School of Medicine, Suwon, 16419, South Korea
| | - Dong Kyung Sung
- Stem Cell and Regenerative Medicine Institute, Samsung Medical Center, Seoul, 06351, South Korea
| | - Se In Sung
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwonro, Gangnam-gu, Seoul, 06351, South Korea.,Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, South Korea
| | - Won Soon Park
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwonro, Gangnam-gu, Seoul, 06351, South Korea. .,Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, South Korea. .,Stem Cell and Regenerative Medicine Institute, Samsung Medical Center, Seoul, 06351, South Korea.
| | - Jee-Yin Ahn
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, 2066, Seobu-ro, Jangan-gu, Suwon, 16419, South Korea. .,Single Cell Network Research Center, Sungkyunkwan University School of Medicine, Suwon, 16419, South Korea. .,Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwonro, Gangnam-gu, Seoul, 06351, South Korea. .,Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, South Korea. .,Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, 06351, South Korea.
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8
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Chen S, Lyu C, Zhou J, Huang S, Zhang Y, Liu G, Liu K, Chen D, Hu Y, Zhou L, Gu Y. TLR4 signaling pathway mediates the LPS/ischemia-induced expression of monocytechemotactic protein-induced protein 1 in microglia. Neurosci Lett 2018; 686:33-40. [PMID: 30179651 DOI: 10.1016/j.neulet.2018.08.052] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 08/24/2018] [Accepted: 08/31/2018] [Indexed: 12/11/2022]
Abstract
Monocytechemotactic protein-induced protein 1 (MCPIP1), a newly recognized mRNA endonuclease, can be induced by lipopolysaccharide (LPS) and ischemic attack, then exerts a negative feedback loop against neuroinflammatory injury, but the specific underlying signaling pathway of the induction is unclear. Toll-like receptors (TLRs) and receptor for advanced glycation end products (RAGE) signaling pathways are involved in LPS/ischemia-evoked inflammation. This study aims to explore which receptor signaling is mainly involved in the induction of MCPIP1 by LPS and ischemic attack. BV2 cells and mice were subjected to LPS stimulation or transient middle cerebral artery occlusion (MCAO) to examine the modulation of MCPIP1. Specific inhibitors for TLR4, TLR2 or RAGE were preadministered to explore the mechanisms of MCPIP1 expression. Results showed that MCPIP1 was significantly increased by LPS and ischemic stress both in vitro and in vivo in time and dose dependent manners. Inhibition of TLR4, rather than TLR2 or RAGE, downregulated the LPS/ischemia-induced expression of MCPIP1 and reduced the levels of TLR4, MyD88, phosphorylated-MAPK (p-P38), phosphorylated-IκBα (p-IκBα), as well as the translocation of NF-κB (p65). In conclusion, we firstly demonstrate that TLR4 signaling pathway, not TLR2 or RAGE, predominantly mediates the LPS/ischemia-induced expression of MCPIP1 in microglia.
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Affiliation(s)
- Shumin Chen
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - Chenfei Lyu
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - Junming Zhou
- Department of Continuing Education Management, The First People Hospital of Foshan, Affiliated Hospital of Sun Yat-Sen University, Foshan, Guangdong 528000, PR China
| | - Shaofei Huang
- Department of Neurology, Guangdong General Hospital's Nanhai Hospital, Foshan, Guangdong 528200, PR China
| | - Yongfang Zhang
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - Guanghui Liu
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - Kewei Liu
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - Danqi Chen
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - Yafang Hu
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - Liang Zhou
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, PR China.
| | - Yong Gu
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, PR China; Department of Encephalopathy, Hainan Province Hospital of Traditional Chinese Medicine, Haikou, Hainan 570203, PR China.
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9
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Anttila JE, Whitaker KW, Wires ES, Harvey BK, Airavaara M. Role of microglia in ischemic focal stroke and recovery: focus on Toll-like receptors. Prog Neuropsychopharmacol Biol Psychiatry 2017; 79:3-14. [PMID: 27389423 PMCID: PMC5214845 DOI: 10.1016/j.pnpbp.2016.07.003] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 06/20/2016] [Accepted: 07/02/2016] [Indexed: 12/21/2022]
Abstract
Stroke is the leading cause of disability in adults. Drug treatments that target stroke-induced pathological mechanisms and promote recovery are desperately needed. In the brain, an ischemic event triggers major inflammatory responses that are mediated by the resident microglial cells. In this review, we focus on the microglia activation after ischemic brain injury as a target of immunomodulatory therapeutics. We divide the microglia-mediated events following ischemic stroke into three categories: acute, subacute, and long-term events. This division encompasses the spatial and temporal dynamics of microglia as they participate in the pathophysiological changes that contribute to the symptoms and sequela of a stroke. The importance of Toll-like receptor (TLR) signaling in the outcomes of these pathophysiological changes is highlighted. Increasing evidence shows that microglia have a complex role in stroke pathophysiology, and they mediate both detrimental and beneficial effects on stroke outcome. So far, most of the pharmacological studies in experimental models of stroke have focused on neuroprotective strategies which are impractical for clinical applications. Post-ischemic inflammation is long lasting and thus, could provide a therapeutic target for novel delayed drug treatment. However, more studies are needed to elucidate the role of microglia in the recovery process from an ischemic stroke and to evaluate the therapeutic potential of modulating post-ischemic inflammation to promote functional recovery.
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Affiliation(s)
- Jenni E Anttila
- Institute of Biotechnology, P.O. Box 56, 00014, University of Helsinki, Finland
| | - Keith W Whitaker
- Intramural Research Program, National Institute on Drug Abuse, NIH, Baltimore, MD, USA; Human Research and Engineering Directorate, US Army Research Laboratory, Aberdeen, Proving Ground, MD 21005, USA
| | - Emily S Wires
- Intramural Research Program, National Institute on Drug Abuse, NIH, Baltimore, MD, USA
| | - Brandon K Harvey
- Intramural Research Program, National Institute on Drug Abuse, NIH, Baltimore, MD, USA
| | - Mikko Airavaara
- Institute of Biotechnology, P.O. Box 56, 00014, University of Helsinki, Finland.
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10
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Fang M, Jiang H, Ye L, Cai C, Hu Y, Pan S, Li P, Xiao J, Lin Z. Metformin treatment after the hypoxia-ischemia attenuates brain injury in newborn rats. Oncotarget 2017; 8:75308-75325. [PMID: 29088867 PMCID: PMC5650422 DOI: 10.18632/oncotarget.20779] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 07/30/2017] [Indexed: 12/15/2022] Open
Abstract
Neonatal hypoxic-ischemic (HI) brain injury is a devastating disease that often leads to death and detrimental neurological deficits. The present study was designed to evaluate the ability of metformin to provide neuroprotection in a model of neonatal hypoxic-ischemic brain injury and to study the associated molecular mechanisms behind these protective effects. Here, we found that metformin treatment remarkably attenuated brain infarct volumes and brain edema at 24 h after HI injury, and the neuroprotection of metformin was associated with inhibition of neuronal apoptosis, suppression of the neuroinflammation and amelioration of the blood brain barrier breakdown. Additionally, metformin treatment conferred long-term protective against brain damage at 7 d after HI injury. Our study indicates that metformin treatment protects against neonatal hypoxic-ischemic brain injury and thus has potential as a therapy for this disease.
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Affiliation(s)
- Mingchu Fang
- Department of Neonatology, The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Huai Jiang
- Department of Neonatology, The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Lixia Ye
- Department of Neonatology, The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Chenchen Cai
- Department of Neonatology, The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Yingying Hu
- Department of Neonatology, The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Shulin Pan
- Department of Neonatology, The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Peijun Li
- Center for Neuroscience Research, Children's National Health System, Washington, DC 20010, United States
| | - Jian Xiao
- Molecular Pharmacology Research Center, School of Pharmacy, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Zhenlang Lin
- Department of Neonatology, The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
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11
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He ML, Lv ZY, Shi X, Yang T, Zhang Y, Li TY, Chen J. Interleukin-10 release from astrocytes suppresses neuronal apoptosis via the TLR2/NFκB pathway in a neonatal rat model of hypoxic-ischemic brain damage. J Neurochem 2017; 142:920-933. [PMID: 28700093 DOI: 10.1111/jnc.14126] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 06/27/2017] [Accepted: 06/28/2017] [Indexed: 12/16/2022]
Abstract
The biological function of interleukin-10 (IL-10) and the relationship between IL-10 secretion and the Toll-like receptor 2 (TLR2) expression levels in the central nervous system following hypoxic-ischemic brain damage (HIBD) are poorly understood. Here, we intend to elucidate the biological function and mechanism of IL-10 secretion following HIBD. In this study, we used a neonatal rat model of HIBD and found that rats injected with adeno-associated virus-IL-10-shRNA (short hairpin RNA) exhibited partially impaired learning and memory function compared to rats administered adeno-associated virus-control-shRNA. In vitro oxygen-glucose deprivation (OGD) induced IL-10 release from astrocytes but not from neurons. Pretreatment with exogenous recombinant IL-10 alleviated OGD-mediated apoptosis of neurons but not astrocytes. In addition, we also observed that hypoxic injury induced a marked increase in IL-10 expression in astrocytes as a result of activation of the TLR2/phosphorylated nuclear factor kappa B (p-NFκB) p65 signaling cascade; furthermore, this effect disappeared upon small interfering RNA targeting rat TLR2 gene (siTLR2) treatment. Pyrrolidinedithiocarbamate, an inhibitor of NFκB activation, reduced the IL-10 expression levels in both OGD-injured astrocytes in vitro and the hippocampi of HIBD rats in vivo but did not significantly affect TLR2 expression. Furthermore, a luciferase assay revealed that p-NFκB p65 could bind the -1700/-1000 bp proximal region of the IL-10 gene promoter to regulate IL-10 secretion from astrocytes and that this interaction could be controlled by OGD treatment. These data suggest that HIBD induces IL-10 secretion from astrocytes to exert a paracrine-induced anti-apoptotic effect on injured neurons via the TLR2/NFκB signaling pathway, which may improve learning and memory dysfunction after ischemic injury.
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Affiliation(s)
- Mu Lan He
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, Chongqing, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China.,Chongqing Stem Cell Therapy Engineering Technical Center, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Ze Yu Lv
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, Chongqing, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China.,Chongqing Stem Cell Therapy Engineering Technical Center, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Xia Shi
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, Chongqing, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China.,Chongqing Stem Cell Therapy Engineering Technical Center, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Ting Yang
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, Chongqing, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China.,Chongqing Stem Cell Therapy Engineering Technical Center, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Yun Zhang
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, Chongqing, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China.,Chongqing Stem Cell Therapy Engineering Technical Center, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Ting-Yu Li
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, Chongqing, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China.,Chongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory Disorders, Chongqing, China
| | - Jie Chen
- Children's Nutrition Research Center, Children's Hospital of Chongqing Medical University, Chongqing, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China.,Chongqing Stem Cell Therapy Engineering Technical Center, Children's Hospital of Chongqing Medical University, Chongqing, China
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12
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Garton TP, He Y, Garton HJL, Keep RF, Xi G, Strahle JM. Hemoglobin-induced neuronal degeneration in the hippocampus after neonatal intraventricular hemorrhage. Brain Res 2016; 1635:86-94. [PMID: 26772987 DOI: 10.1016/j.brainres.2015.12.060] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 12/28/2015] [Accepted: 12/29/2015] [Indexed: 11/16/2022]
Abstract
Neuronal degeneration following neonatal intraventricular hemorrhage (IVH) is incompletely understood. Understanding the mechanisms of degeneration and cell loss may point toward specific treatments to limit injury. We evaluated the role of hemoglobin (Hb) in cell death after intraventricular injection in neonatal rats. Hb was injected into the right lateral ventricle of post-natal day 7 rats. Rats exposed to anesthesia were used for controls. The CA-1 region of the hippocampus was analyzed via immunohistochemistry, hematoxylin and eosin (H&E) staining, Fluoro-Jade C staining, Western blots, and double-labeling stains. Compared to controls, intraventricular injection of Hb decreased hippocampal volume (27% decrease; p<0.05), induced neuronal loss (31% loss; p<0.01), and increased neuronal degeneration (2.7 fold increase; p<0.01), which were all significantly reduced with the iron chelator, deferoxamine. Hb upregulated p-JNK (1.8 fold increase; p<0.05) and increased expression of the Hb/haptoglobin endocytotic receptor CD163 in neurons in vivo and in vitro (cultured cortical neurons). Hb induced expression of the CD163 receptor, which co-localized with p-JNK in hippocampal neurons, suggesting a potential pathway by which Hb enters the neuron to result in cell death. There were no differences in neuronal loss or degenerating neurons in Hb-injected animals that developed hydrocephalus versus those that did not. Intraventricular injection of Hb causes hippocampal neuronal degeneration and cell loss and increases brain p-JNK levels. p-JNK co-localized with the Hb/haptoglobin receptor CD163, suggesting a novel pathway by which Hb enters the neuron after IVH to result in cell death.
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Affiliation(s)
- Thomas P Garton
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | - Yangdong He
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | - Hugh J L Garton
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | - Richard F Keep
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | - Guohua Xi
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | - Jennifer M Strahle
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA; Department of Neurological Surgery, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, MO, USA.
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