1
|
Li C, Jiang M, Chen Z, Hu Q, Liu Z, Wang J, Yin X, Wang J, Wu M. The neuroprotective effects of normobaric oxygen therapy after stroke. CNS Neurosci Ther 2024; 30:e14858. [PMID: 39009510 PMCID: PMC11250159 DOI: 10.1111/cns.14858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Revised: 06/29/2024] [Accepted: 07/03/2024] [Indexed: 07/17/2024] Open
Abstract
BACKGROUND Stroke, including ischemic and hemorrhagic stroke, is a severe and prevalent acute cerebrovascular disease. The development of hypoxia following stroke can trigger a cascade of pathological events, including mitochondrial dysfunction, energy deficiency, oxidative stress, neuroinflammation, and excitotoxicity, all of which are often associated with unfavorable prognosis. Nonetheless, a noninvasive intervention, referred to as normobaric hyperoxia (NBO), is known to have neuroprotective effects against stroke. RESULTS NBO can exert neuroprotective effects through various mechanisms, such as the rescue of hypoxic tissues, preservation of the blood-brain barrier, reduction of brain edema, alleviation of neuroinflammation, improvement of mitochondrial function, mitigation of oxidative stress, reduction of excitotoxicity, and inhibition of apoptosis. These mechanisms may help improve the prognosis of stroke patients. CONCLUSIONS This review summarizes the mechanism by which hypoxia causes brain injury and how NBO can act as a neuroprotective therapy to treat stroke. We conclude that NBO has significant potential for treating stroke and may represent a novel therapeutic strategy.
Collapse
Affiliation(s)
- Chuan Li
- Department of Medical LaboratoryAffiliated Hospital of Jiujiang UniversityJiujiangJiangxiChina
| | - Min Jiang
- Jiujiang Clinical Precision Medicine Research CenterJiujiangJiangxiChina
| | - Zhiying Chen
- Department of NeurologyAffiliated Hospital of Jiujiang UniversityJiujiangJiangxiChina
| | - Qiongqiong Hu
- Department of NeurologyZhengzhou Central Hospital, Zhengzhou UniversityZhengzhouHenanChina
| | - Ziying Liu
- Department of Medical LaboratoryAffiliated Hospital of Jiujiang UniversityJiujiangJiangxiChina
| | - Junmin Wang
- Department of Human AnatomySchool of Basic Medical Sciences, Zhengzhou UniversityZhengzhouHenanChina
| | - Xiaoping Yin
- Department of NeurologyAffiliated Hospital of Jiujiang UniversityJiujiangJiangxiChina
| | - Jian Wang
- Department of Human AnatomySchool of Basic Medical Sciences, Zhengzhou UniversityZhengzhouHenanChina
| | - Moxin Wu
- Department of Medical LaboratoryAffiliated Hospital of Jiujiang UniversityJiujiangJiangxiChina
- Jiujiang Clinical Precision Medicine Research CenterJiujiangJiangxiChina
| |
Collapse
|
2
|
Wang Y, Ni P, Zhuang D, Zhou P, Zhu F, Yin D, Zhu R, Mei B, Hu S. Early hyperbaric oxygen therapy through regulating the HIF-1α signaling pathway attenuates Neuroinflammation and behavioral deficits in a mouse model of Sepsis-associated encephalopathy. J Neuroimmunol 2024; 391:578367. [PMID: 38735091 DOI: 10.1016/j.jneuroim.2024.578367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 04/18/2024] [Accepted: 05/05/2024] [Indexed: 05/14/2024]
Abstract
BACKGROUND Sepsis-associated encephalopathy (SAE) presents a significant clinical challenge, associated with increased mortality and healthcare expenses. Hyperbaric oxygen therapy (HBOT), involving inhaling pure or highly concentrated oxygen under pressures exceeding one atmosphere, has demonstrated neuroprotective effects in various conditions. However, the precise mechanisms underlying its protective actions against sepsis-associated brain injury remain unclear. This study aimed to determine whether HBOT protects against SAE and to elucidate the impact of the hypoxia-inducible factor-1α (HIF-1α) signaling pathway on SAE. METHODS The experiment consisted of two parts. In the first part, C57BL/6 J male mice were divided into five groups using a random number table method: control group, sham surgery group, sepsis group, HBOT + sepsis group, and HBOT + sham surgery group. In the subsequent part, C57BL/6 J male mice were divided into four groups: sepsis group, HBOT + sepsis group, HIF-1α + HBOT + sepsis group, and HIF-1α + sepsis group. Sepsis was induced via cecal ligation and puncture (CLP). Hyperbaric oxygen therapy was administered at 1 h and 4 h post-CLP. After 24 h, blood and hippocampal tissue were collected for cytokine measurements. HIF-1α, TNF-α, IL-1β, and IL-6 expression were assessed via ELISA and western blotting. Microglial expression was determined by immunofluorescence. Blood-brain barrier permeability was quantified using Evans Blue. Barnes maze and fear conditioning were conducted 14 days post-CLP to evaluate learning and memory. RESULTS Our findings reveal that CLP-induced hippocampus-dependent cognitive deficits coincided with elevated HIF-1α and increased TNF-α, IL-1β, and IL-6 levels in both blood and hippocampus. Observable activation of microglial cells in the hippocampus and increased blood-brain barrier (BBB) permeability were also evident. HBOT mitigated HIF-1α, TNF-α, IL-1β, and IL-6 levels, attenuated microglial activation in the hippocampus, and significantly improved learning and memory deficits in CLP-exposed mice. Additionally, these outcomes were corroborated by injecting a lentivirus that overexpressed HIF-1α into the hippocampal region of the mice. CONCLUSION HIF-1α escalation induced peripheral and central inflammatory factors, promoting microglial activation, BBB impairment, and cognitive dysfunction. However, HBOT ameliorated these effects by reducing HIF-1α levels in Sepsis-Associated Encephalopathy.
Collapse
Affiliation(s)
- Yan Wang
- School of Nursing, Anhui Medical University, Hefei, Anhui Province, China; The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, China
| | - Ping Ni
- School of Nursing, Anhui Medical University, Hefei, Anhui Province, China
| | - Dongmei Zhuang
- School of Nursing, Anhui Medical University, Hefei, Anhui Province, China
| | - Peng Zhou
- The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, China
| | - Furong Zhu
- School of Nursing, Anhui Medical University, Hefei, Anhui Province, China
| | - Danqiao Yin
- The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, China
| | - Rui Zhu
- The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, China
| | - Bin Mei
- Department of Anesthesiology, the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, China.
| | - Shaohua Hu
- Department of Nursing, the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, China.
| |
Collapse
|
3
|
Clemons GA, Silva ACE, Acosta CH, Udo MSB, Tesic V, Rodgers KM, Wu CYC, Citadin CT, Lee RHC, Neumann JT, Allani S, Prentice H, Zhang Q, Lin HW. Protein arginine methyltransferase 4 modulates nitric oxide synthase uncoupling and cerebral blood flow in Alzheimer's disease. J Cell Physiol 2024; 239:e30858. [PMID: 36036549 PMCID: PMC9971360 DOI: 10.1002/jcp.30858] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 07/17/2022] [Accepted: 08/08/2022] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease (AD) is the leading cause of mortality, disability, and long-term care burden in the United States, with women comprising the majority of AD diagnoses. While AD-related dementia is associated with tau and amyloid beta accumulation, concurrent derangements in cerebral blood flow have been observed alongside these proteinopathies in humans and rodent models. The homeostatic production of nitric oxide synthases (NOS) becomes uncoupled in AD which leads to decreased NO-mediated vasodilation and oxidative stress via the production of peroxynitrite (ONOO-∙) superoxide species. Here, we investigate the role of the novel protein arginine methyltransferase 4 (PRMT4) enzyme function and its downstream product asymmetric dimethyl arginine (ADMA) as it relates to NOS dysregulation and cerebral blood flow in AD. ADMA (type-1 PRMT product) has been shown to bind NOS as a noncanonic ligand causing enzymatic dysfunction. Our results from RT-qPCR and protein analyses suggest that aged (9-12 months) female mice bearing tau- and amyloid beta-producing transgenic mutations (3xTg-AD) express higher levels of PRMT4 in the hippocampus when compared to age- and sex-matched C57BL6/J mice. In addition, we performed studies to quantify the expression and activity of different NOS isoforms. Furthermore, laser speckle contrast imaging analysis was indicative that 3xTg-AD mice have dysfunctional NOS activity, resulting in reduced production of NO metabolites, enhanced production of free-radical ONOO-, and decreased cerebral blood flow. Notably, the aforementioned phenomena can be reversed via pharmacologic PRMT4 inhibition. Together, these findings implicate the potential importance of PRMT4 signaling in the pathogenesis of Alzheimer's-related cerebrovascular derangement.
Collapse
Affiliation(s)
- Garrett A Clemons
- Department of Cellular Biology & Anatomy, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA
| | | | - Christina H Acosta
- Department of Cellular Biology & Anatomy, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA
| | - Mariana Sayuri Berto Udo
- Department of Neurology, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA
| | - Vesna Tesic
- Department of Neurology, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA
| | - Krista M Rodgers
- Department of Cellular Biology & Anatomy, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA
| | - Celeste Yin-Chieh Wu
- Department of Neurology, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA
| | - Cristiane T Citadin
- Department of Cellular Biology & Anatomy, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA
| | - Reggie Hui-Chao Lee
- Department of Neurology, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA
| | - Jake T Neumann
- Department of Biomedical Sciences, West Virginia School of Osteopathic Medicine, Lewisburg, West Virginia, USA
| | - Shailaja Allani
- Center for Molecular Biology and Biotechnology, Florida Atlantic University, Jupiter, Florida, USA
| | - Howard Prentice
- Department of Biomedical Sciences, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida, USA
| | - Quanguang Zhang
- Department of Neurology, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA
| | - Hung Wen Lin
- Department of Cellular Biology & Anatomy, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA
- Department of Neurology, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA
| |
Collapse
|
4
|
Quan H, Zhang R. Microglia dynamic response and phenotype heterogeneity in neural regeneration following hypoxic-ischemic brain injury. Front Immunol 2023; 14:1320271. [PMID: 38094292 PMCID: PMC10716326 DOI: 10.3389/fimmu.2023.1320271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 11/14/2023] [Indexed: 12/18/2023] Open
Abstract
Hypoxic-ischemic brain injury poses a significant threat to the neural niche within the central nervous system. In response to this pathological process, microglia, as innate immune cells in the central nervous system, undergo rapid morphological, molecular and functional changes. Here, we comprehensively review these dynamic changes in microglial response to hypoxic-ischemic brain injury under pathological conditions, including stroke, chronic intermittent hypoxia and neonatal hypoxic-ischemic brain injury. We focus on the regulation of signaling pathways under hypoxic-ischemic brain injury and further describe the process of microenvironment remodeling and neural tissue regeneration mediated by microglia after hypoxic-ischemic injury.
Collapse
Affiliation(s)
- Hongxin Quan
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, Yunnan, China
- Yunnan Key Laboratory of Primate Biomedical Research, Kunming, Yunnan, China
| | - Runrui Zhang
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, Yunnan, China
- Yunnan Key Laboratory of Primate Biomedical Research, Kunming, Yunnan, China
| |
Collapse
|
5
|
Lv J, Qi P, Bai LH, Yan XD, Zhang L. Review of the relationship and underlying mechanisms between the Qinghai-Tibet plateau and host intestinal flora. Front Microbiol 2022; 13:1055632. [PMID: 36523840 PMCID: PMC9745141 DOI: 10.3389/fmicb.2022.1055632] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 11/07/2022] [Indexed: 12/01/2023] Open
Abstract
The intestinal microbial community is the largest ecosystem in the human body, in which the intestinal flora plays a dominant role and has a wide range of biological functions. However, it is vulnerable to a variety of factors, and exposure to extreme environments at high altitudes, as seen on the Qinghai-Tibet plateau, may cause changes in the structure and function of the host intestinal flora. Conversely, the intestinal flora can help the host adapt to the plateau environment through a variety of ways. Herein, we review the relationship and underlying mechanism between the host intestinal flora and the plateau environment by discussing the characteristics of the plateau environment, its influence on the intestinal flora, and the important role of the intestinal flora in host adaptation to the plateau environment. This review aimed to provide a reference for maintaining the health of the plateau population.
Collapse
Affiliation(s)
- Jin Lv
- The First Clinical Medical College, Lanzhou University, Lanzhou, China
- Department of General Surgery, The First Hospital of Lanzhou University, Lanzhou, China
- Key Laboratory of Biotherapy and Regenerative Medicine of Gansu Province, The First Hospital of Lanzhou University, Lanzhou, China
| | - Ping Qi
- The First Clinical Medical College, Lanzhou University, Lanzhou, China
- Department of General Surgery, The First Hospital of Lanzhou University, Lanzhou, China
- Key Laboratory of Biotherapy and Regenerative Medicine of Gansu Province, The First Hospital of Lanzhou University, Lanzhou, China
| | - Liu-Hui Bai
- The First Clinical Medical College, Lanzhou University, Lanzhou, China
- Department of General Surgery, The First Hospital of Lanzhou University, Lanzhou, China
- Key Laboratory of Biotherapy and Regenerative Medicine of Gansu Province, The First Hospital of Lanzhou University, Lanzhou, China
| | - Xiang-Dong Yan
- The First Clinical Medical College, Lanzhou University, Lanzhou, China
- Department of General Surgery, The First Hospital of Lanzhou University, Lanzhou, China
- Key Laboratory of Biotherapy and Regenerative Medicine of Gansu Province, The First Hospital of Lanzhou University, Lanzhou, China
| | - Lei Zhang
- The First Clinical Medical College, Lanzhou University, Lanzhou, China
- Department of General Surgery, The First Hospital of Lanzhou University, Lanzhou, China
- Key Laboratory of Biotherapy and Regenerative Medicine of Gansu Province, The First Hospital of Lanzhou University, Lanzhou, China
| |
Collapse
|
6
|
Emamnejad R, Dass M, Mahlis M, Bozkurt S, Ye S, Pagnin M, Theotokis P, Grigoriadis N, Petratos S. Thyroid hormone-dependent oligodendroglial cell lineage genomic and non-genomic signaling through integrin receptors. Front Pharmacol 2022; 13:934971. [PMID: 36133808 PMCID: PMC9483185 DOI: 10.3389/fphar.2022.934971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 07/18/2022] [Indexed: 11/13/2022] Open
Abstract
Multiple sclerosis (MS) is a heterogeneous autoimmune disease whereby the pathological sequelae evolve from oligodendrocytes (OLs) within the central nervous system and are targeted by the immune system, which causes widespread white matter pathology and results in neuronal dysfunction and neurological impairment. The progression of this disease is facilitated by a failure in remyelination following chronic demyelination. One mediator of remyelination is thyroid hormone (TH), whose reliance on monocarboxylate transporter 8 (MCT8) was recently defined. MCT8 facilitates the entry of THs into oligodendrocyte progenitor cell (OPC) and pre-myelinating oligodendrocytes (pre-OLs). Patients with MS may exhibit downregulated MCT8 near inflammatory lesions, which emphasizes an inhibition of TH signaling and subsequent downstream targeted pathways such as phosphoinositide 3-kinase (PI3K)-Akt. However, the role of the closely related mammalian target of rapamycin (mTOR) in pre-OLs during neuroinflammation may also be central to the remyelination process and is governed by various growth promoting signals. Recent research indicates that this may be reliant on TH-dependent signaling through β1-integrins. This review identifies genomic and non-genomic signaling that is regulated through mTOR in TH-responsive pre-OLs and mature OLs in mouse models of MS. This review critiques data that implicates non-genomic Akt and mTOR signaling in response to TH-dependent integrin receptor activation in pre-OLs. We have also examined whether this can drive remyelination in the context of neuroinflammation and associated sequelae. Importantly, we outline how novel therapeutic small molecules are being designed to target integrin receptors on oligodendroglial lineage cells and whether these are viable therapeutic options for future use in clinical trials for MS.
Collapse
Affiliation(s)
- Rahimeh Emamnejad
- Department of Neuroscience, Central Clinical School, Monash University, Prahran, VIC, Australia
| | - Mary Dass
- Department of Neuroscience, Central Clinical School, Monash University, Prahran, VIC, Australia
| | - Michael Mahlis
- Department of Neuroscience, Central Clinical School, Monash University, Prahran, VIC, Australia
| | - Salome Bozkurt
- Department of Neuroscience, Central Clinical School, Monash University, Prahran, VIC, Australia
| | - Sining Ye
- Department of Neuroscience, Central Clinical School, Monash University, Prahran, VIC, Australia
| | - Maurice Pagnin
- Department of Neuroscience, Central Clinical School, Monash University, Prahran, VIC, Australia
| | - Paschalis Theotokis
- B’, Department of Neurology, Laboratory of Experimental Neurology and Neuroimmunology, AHEPA University Hospital, Thessaloniki, Greece
| | - Nikolaos Grigoriadis
- B’, Department of Neurology, Laboratory of Experimental Neurology and Neuroimmunology, AHEPA University Hospital, Thessaloniki, Greece
| | - Steven Petratos
- Department of Neuroscience, Central Clinical School, Monash University, Prahran, VIC, Australia
- *Correspondence: Steven Petratos,
| |
Collapse
|
7
|
Bonilla-Jaime H, Zeleke H, Rojas A, Espinosa-Garcia C. Sleep Disruption Worsens Seizures: Neuroinflammation as a Potential Mechanistic Link. Int J Mol Sci 2021; 22:12531. [PMID: 34830412 PMCID: PMC8617844 DOI: 10.3390/ijms222212531] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Revised: 11/16/2021] [Accepted: 11/18/2021] [Indexed: 12/13/2022] Open
Abstract
Sleep disturbances, such as insomnia, obstructive sleep apnea, and daytime sleepiness, are common in people diagnosed with epilepsy. These disturbances can be attributed to nocturnal seizures, psychosocial factors, and/or the use of anti-epileptic drugs with sleep-modifying side effects. Epilepsy patients with poor sleep quality have intensified seizure frequency and disease progression compared to their well-rested counterparts. A better understanding of the complex relationship between sleep and epilepsy is needed, since approximately 20% of seizures and more than 90% of sudden unexpected deaths in epilepsy occur during sleep. Emerging studies suggest that neuroinflammation, (e.g., the CNS immune response characterized by the change in expression of inflammatory mediators and glial activation) may be a potential link between sleep deprivation and seizures. Here, we review the mechanisms by which sleep deprivation induces neuroinflammation and propose that neuroinflammation synergizes with seizure activity to worsen neurodegeneration in the epileptic brain. Additionally, we highlight the relevance of sleep interventions, often overlooked by physicians, to manage seizures, prevent epilepsy-related mortality, and improve quality of life.
Collapse
Affiliation(s)
- Herlinda Bonilla-Jaime
- Departamento de Biología de la Reproducción, Área de Biología Conductual y Reproductiva, Universidad Autónoma Metropolitana-Iztapalapa, Ciudad de Mexico CP 09340, Mexico;
| | - Helena Zeleke
- Neuroscience and Behavioral Biology Program, College of Arts and Sciences, Emory University, Atlanta, GA 30322, USA;
| | - Asheebo Rojas
- Department of Pharmacology and Chemical Biology, School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Claudia Espinosa-Garcia
- Department of Pharmacology and Chemical Biology, School of Medicine, Emory University, Atlanta, GA 30322, USA
| |
Collapse
|
8
|
An evidence update on the protective mechanism of tangeretin against neuroinflammation based on network pharmacology prediction and transcriptomic analysis. Eur J Pharmacol 2021; 906:174094. [PMID: 34087222 DOI: 10.1016/j.ejphar.2021.174094] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 04/03/2021] [Accepted: 04/07/2021] [Indexed: 01/05/2023]
Abstract
Although the protective effects of tangeretin on neuroinflammation have been proven in cell and animal experiments, few studies explore its underlying molecular mechanism. In this study, we used the network pharmacology method combined with the transcriptome approach to investigate its underlying anti-inflammatory mechanism in human microglial cells. Based on network pharmacology analysis, four putative target proteins and ten potential pathways were identified. Among them, vascular endothelial growth factor A (VEGFA), epidermal growth factor receptor (EGFR) and the related phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT), the mitogen-activated protein kinase (MAPK), mechanistic target of rapamycin (mTOR) signaling pathway were well-supported by transcriptome data. Meanwhile, transcriptome analysis supplemented two crucial targets: the insulin receptor (InsR) and insulin-like growth factor-I (IGF-1) receptor. Subsequently, VEGFA, EGFR, IGF-1 receptor, and InsR were further verified on the protein level. Taken together, we assumed that tangeretin could exert protective effects on neuroinflammation by decreasing the expression of VEGFA, EGFR, InsR, and IGF-1 receptor in the PI3K-AKT, MAPK, mTOR signaling pathway. More importantly, it is for the first time to show that the anti-neuroinflammatory effects of tangeretin through VEGFA, EGFR, IGF-1 receptor, InsR, and mTOR signaling pathway. These works offer new insight into the anti-neuroinflammatory functions of tangeretin and propose novel information on further anti-inflammatory mechanism studies.
Collapse
|
9
|
VEGF/VEGFR-2 system exerts neuroprotection against Phoneutria nigriventer spider envenomation through PI3K-AKT-dependent pathway. Toxicon 2020; 185:76-90. [PMID: 32649934 DOI: 10.1016/j.toxicon.2020.06.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 06/23/2020] [Accepted: 06/23/2020] [Indexed: 01/19/2023]
Abstract
This study was undertaken to elucidate why VEGF/VEGFR-2 is elevated in the hippocampus of rats injected with Phoneutria nigriventer spider venom (PNV). PNV delays Na+ channels inactivation; blocks Ca2+ and K+ channels, increases glutamate release, causes blood-brain breakdown (BBBb), brain edema and severe excitotoxicity. Analytical FT-IR spectroscopy showed profound alteration in molecular biochemical state, with evidences for VEGFR-2 (KDR/Flk-1) signaling mediation. By blocking VEGF/VEGFR-2 binding via pre-treatment with itraconazole we demonstrated that animals' condition was deteriorated soon at 1-2 h post-PNV exposure concurrently with decreased expression of VEGF, BBB-associated proteins, ZO-1, β-catenin, laminin, P-gp (P-glycoprotein), Neu-N (neuron's viability marker) and MAPKphosphorylated-p38, while phosphorylated-ERK and Src pathways were increased. At 5 h and coinciding with incipient signs of animals' recuperation, the proteins associated with protection (HIF-1α, VEGF, VEGFR-1, VEGFR-2, Neu-N, occludin, β-catenin, laminin, P-gp efflux protein, phosphorylated-p38) increased thus indicating p38 pathway activation together with paracellular route strengthening. However, the BBB transcellular trafficking and caspase-3 increased (pro-apoptotic pathway activation). At 24 h, the transcellular route reestablished physiological state but the pro-survival pathway PI3K/(p-Akt) dropped in animals underwent VEGF/VEGFR-2 binding inhibition, whereas it was significantly activated at matched interval in PNV group without prior itraconazole; these results demonstrate impaired VEGF' survival effects at 24 h. The inhibition of VEGF/VEGFR-2 binding identified 5 h as turning point at which multi-level dynamic interplay was elicited to reverse hippocampal damage. Collectively, the data confirmed VEGFR-2 signaling via serine-threonine kinase Akt as neuroprotective pathway against PNV-induced damage. Further studies are needed to elucidate mechanisms underlying PNV effects.
Collapse
|
10
|
Luan P, Ding X, Xu J, Jiang L, Xu Y, Zhu Y, Li R, Zhang J. Salvianolate reduces neuronal apoptosis by suppressing OGD-induced microglial activation. Life Sci 2020; 260:118393. [PMID: 32898527 DOI: 10.1016/j.lfs.2020.118393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/29/2020] [Accepted: 09/01/2020] [Indexed: 12/22/2022]
Abstract
AIMS The aim of this study was to investigate the mechanism of pro-inflammatory phenotype transformation of microglia induced by oxygen-glucose deprivation (OGD), and how salvianolate regulates the polarization of microglia to exert neuroprotective effects. MAIN METHODS The immunofluorescence and western blot experiments were used to verify the injury effect on neuronal cells after inflammatory polarization of microglia. Secondly, immunofluorescence staining and western blot were analyzed inflammatory phenotype of microglia and TLR4 signaling pathway after salvianolate treatment. RT-qPCR and ELISA assays were showed the levels of RNA and proteins of inflammatory factors in microglia. Finally, flow cytometry and western blot assay proved that salvianolate had a certain protective effect on neuronal injury after inhibiting the phenotype of microglia. KEY FINDINGS The OGD condition could promote inflammation and activate of TLR4 signal pathway in microglia, and the polarization of microglia triggered caspase-3 signal pathway of neuronal cell. The optimal concentrations of salvianolate were incubated with microglia under OGD condition, which could reduce the reactive oxygen species (ROS) expression (P = 0.002) and also regulate the activity of SOD, CAT and GSH-px enzymes (P < 0.05). Moreover, salvianolate treatment could inhibit TLR4 signal pathway (P = 0.012), suppress the pro-inflammatory phenotype of microglia in OGD condition (P = 0.018), and reduce the expression of IL-6 and TNF-α (P < 0.05). Finally, neuronal damage induced by microglia under OGD condition was reversed after administration of the microglia supernatant after salvianolate treatment. SIGNIFICANCE Salvianolate, as an antioxidant, plays a neuroprotective role by inhibiting the pro-inflammatory phenotype and decreasing the expression of ROS in microglia.
Collapse
Affiliation(s)
- Pengwei Luan
- The Research Center of Chiral Drugs, Innovation Research Institute of Traditional, Chinese Medicine (IRI), Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China; School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Xinyue Ding
- The Research Center of Chiral Drugs, Innovation Research Institute of Traditional, Chinese Medicine (IRI), Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Jiazhen Xu
- The Research Center of Chiral Drugs, Innovation Research Institute of Traditional, Chinese Medicine (IRI), Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Lixian Jiang
- The Research Center of Chiral Drugs, Innovation Research Institute of Traditional, Chinese Medicine (IRI), Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yulan Xu
- The Research Center of Chiral Drugs, Innovation Research Institute of Traditional, Chinese Medicine (IRI), Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China; School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Yuying Zhu
- The Research Center of Chiral Drugs, Innovation Research Institute of Traditional, Chinese Medicine (IRI), Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Ruixiang Li
- The Research Center of Chiral Drugs, Innovation Research Institute of Traditional, Chinese Medicine (IRI), Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Jiange Zhang
- The Research Center of Chiral Drugs, Innovation Research Institute of Traditional, Chinese Medicine (IRI), Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
| |
Collapse
|
11
|
Heras-Garvin A, Danninger C, Eschlböck S, Holton JL, Wenning GK, Stefanova N. Signs of Chronic Hypoxia Suggest a Novel Pathophysiological Event in α-Synucleinopathies. Mov Disord 2020; 35:2333-2338. [PMID: 32881058 PMCID: PMC7818169 DOI: 10.1002/mds.28229] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 06/24/2020] [Accepted: 07/14/2020] [Indexed: 01/13/2023] Open
Abstract
Background Multiple system atrophy (MSA) and Parkinson's disease (PD) patients develop respiratory and cardiovascular disturbances including obstructive sleep apnea, orthostatic hypotension, and nocturnal stridor. We hypothesized that, associated with these respiratory and cardiovascular disturbances, hypoxic events may occur in MSA and PD brains that may play a role in disease progression. The objective of this study was to evaluate the presence of hypoxia in nonneurological controls and PD and MSA patients. Methods Molecular levels of hypoxia markers were measured in postmortem brain tissue from controls and PD and MSA cases. Results MSA brain showed signs of chronic hypoxia characterized by the significant accumulation of the hypoxic marker HIF2α as compared to PD patients and controls. We detected no differences between MSA subtypes. Signs of hypoxia were also observed in PD patients with a clinical presentation similar to the MSA cases. Conclusions The results obtained from this study suggest a new alternative pathway associated with α‐synucleinopathies that may contribute to the pathogenesis of these disorders. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society
Collapse
Affiliation(s)
- Antonio Heras-Garvin
- Division of Neurobiology, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Christoph Danninger
- Division of Neurobiology, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Sabine Eschlböck
- Division of Neurobiology, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Janice L Holton
- Division of Neuropathology, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Gregor K Wenning
- Division of Neurobiology, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Nadia Stefanova
- Division of Neurobiology, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| |
Collapse
|
12
|
Yao YY, Ling EA, Lu D. Microglia mediated neuroinflammation - signaling regulation and therapeutic considerations with special reference to some natural compounds. Histol Histopathol 2020; 35:1229-1250. [PMID: 32662061 DOI: 10.14670/hh-18-239] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Neuroinflammation plays a central role in multiple neurodegenerative diseases and neurological disorders such as Alzheimer's disease (AD), Parkinson's disease (PD), cerebral ischemic injury etc. In this connection, microglia, the key players in the central nervous system, mediate the inflammatory response process. In brain injuries, activated microglia can clear the cellular debris and invading pathogens and release neurotrophic factors; however, prolonged microglia activation may cause neuronal death through excessive release of inflammatory mediators. Therefore, it is of paramount importance to understand the underlying molecular mechanisms of microglia activation to design an effective therapeutic strategy to alleviate neuronal injury. Recent studies have shown that some natural compounds and herbal extracts possess anti-inflammatory properties that may suppress microglial activation and ameliorate neuroinflammation and hence are neuroprotective. In this review, we will update some of the common signaling pathways that regulate microglia activation. Among the various signaling pathways, the Notch-1, mitogen-activated protein kinases (MAPKs), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) have been reported to exacerbate microglia mediated neuroinflammation that is implicated in different neuropathological diseases. The search for natural compounds or agents, specifically those derived from natural herbal extracts such as Gastrodin, scutellarin, RG1 etc. has been the focus of many of our recent studies because they have been found to regulate microglia activation. The pharmacological effects of these agents and their potential mechanisms for regulating microglia activation are systematically reviewed here for a fuller understanding of their biochemical action and therapeutic potential for treatment of microglia mediated neuropathological diseases.
Collapse
Affiliation(s)
- Yue-Yi Yao
- Technology Transfer Center, Kunming Medical University, Kunming, China
| | - Eng-Ang Ling
- Department of Anatomy, Young Loo Lin School of Medicine, National University of Singapore, Singapore.
| | - Di Lu
- Technology Transfer Center, Kunming Medical University, Kunming, China.
| |
Collapse
|
13
|
Comparative transcriptomic and proteomic analyses provide insights into functional genes for hypoxic adaptation in embryos of Tibetan chickens. Sci Rep 2020; 10:11213. [PMID: 32641697 PMCID: PMC7343830 DOI: 10.1038/s41598-020-68178-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 04/22/2020] [Indexed: 12/11/2022] Open
Abstract
The Tibetan chicken is a unique breed that has adapted to the high-altitude hypoxic conditions of the Tibetan plateau. A number of positively selected genes have been reported in these chickens; however, the mechanisms of gene expression for hypoxia adaptation are not fully understood. In the present study, eggs from Tibetan and Chahua chickens were incubated under hypoxic and normoxic conditions, and vascularization in the chorioallantoic membrane (CAM) of embryos was observed. We found that the vessel density index in the CAM of Tibetan chickens was lower than in Chahua chickens under hypoxia conditions. Transcriptomic and proteomic analyses of CAM tissues were performed in Tibetan and Chahua chicken embryos under hypoxic incubation using RNA-Seq and iTRAQ. We obtained 160 differentially expressed genes and 387 differentially expressed proteins that were mainly enriched in angiogenesis, vasculature development, blood vessel morphogenesis, blood circulation, renin-angiotensin system, and HIF-1 and VEGF signaling pathways. Twenty-six genes involved in angiogenesis and blood circulation, two genes involved in ion transport, and six genes that regulated energy metabolism were identified as candidate functional genes in regulating hypoxic adaptation of chicken embryos. This research provided insights into the molecular mechanism of hypoxia adaptation in Tibetan chickens.
Collapse
|
14
|
Rhein Suppresses Neuroinflammation via Multiple Signaling Pathways in LPS-Stimulated BV2 Microglia Cells. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2020; 2020:7210627. [PMID: 32714414 PMCID: PMC7341424 DOI: 10.1155/2020/7210627] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 05/24/2020] [Accepted: 05/29/2020] [Indexed: 01/09/2023]
Abstract
As a bioactive absorbed compound of rhubarb, Rhein is applied for the treatment of brain injury. However, the underlying pharmacological mechanisms remain unclear. In this study, we aimed to explore antineuroinflammatory functions and underlying mechanisms of Rhein in vitro. BV2 microglia cells were chosen and irritated by LPS. The influence of Rhein on cell viability was determined using MTT assay. We finely gauged the proinflammatory cytokines of TNF-α and IL-1β through tests of immunofluorescence staining, ELISA, RT-qPCR, and western blot. Additionally, mediators including IL-6, IL-12, iNOS, and IL-10 were surveyed by ELISA. Furthermore, protein levels of the underlying signaling pathways (PI3K/Akt, p38, ERK1/2, and TLR4/NF-κB) were tested adopting western blot. We found that Rhein reduced the secretion of pivotal indicators including TNF-α and IL-1β, effectively restraining their mRNA and protein expression in LPS-activated BV2 microglial cells. Besides, Rhein treatment demoted the production of IL-6, IL-12, and iNOS and promoted the excretion of IL-10. Subsequent mechanistic experiments revealed that Rhein obviously downregulated the phosphorylation levels of PI3K, Akt, p38, and ERK1/2 and simultaneously upregulated the PTEN expression. In addition, Rhein antagonized the increase of TLR4, p-IκBα, and NF-κB. In summary, Rhein suppresses neuroinflammation via multiple signaling pathways (PI3K/Akt, p38, ERK1/2, and TLR4/NF-κB) in LPS-stimulated BV2 microglia cells. This study highlights a natural agent for prevention and treatment of neuroinflammation.
Collapse
|
15
|
Propofol Attenuates Hypoxia-Induced Inflammation in BV2 Microglia by Inhibiting Oxidative Stress and NF- κB/Hif-1 α Signaling. BIOMED RESEARCH INTERNATIONAL 2020; 2020:8978704. [PMID: 32420378 PMCID: PMC7204316 DOI: 10.1155/2020/8978704] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 04/11/2020] [Accepted: 04/17/2020] [Indexed: 01/29/2023]
Abstract
Hypoxia-induced neuroinflammation typically causes neurological damage and can occur during stroke, neonatal hypoxic-ischemic encephalopathy, and other diseases. Propofol is widely used as an intravenous anesthetic. Studies have shown that propofol has antineuroinflammatory effect. However, the underlying mechanism remains to be fully elucidated. Thus, we aimed to investigate the beneficial effects of propofol against hypoxia-induced neuroinflammation and elucidated its potential cellular and biochemical mechanisms of action. In this study, we chose cobalt chloride (CoCl2) to establish a hypoxic model. We found that propofol decreased hypoxia-induced proinflammatory cytokines (TNFα, IL-1β, and IL-6) in BV2 microglia, significantly suppressed the excessive production of reactive oxygen species, and increased the total antioxidant capacity and superoxide dismutase activity. Furthermore, propofol attenuated the hypoxia-induced decrease in mitochondrial membrane potential andy 2 strongly inhibited protein expression of nuclear factor-kappa B (NF-κB) subunit p65 and hypoxia inducible factor-1α (Hif-1α) in hypoxic BV2 cells. To investigate the role of NF-κB p65, specific small interfering RNA (siRNA) against NF-κB p65 were transfected into BV2 cells, followed by exposure to hypoxia for 24 h. Hypoxia-induced Hif-1α production was downregulated after NF-κB p65 silencing. Further, propofol suppressed Hif-1α expression by inhibiting the upregulation of NF-κB p65 after exposure to hypoxia in BV2 microglia. In summary, propofol attenuates hypoxia-induced neuroinflammation, at least in part by inhibiting oxidative stress and NF-κB/Hif-1α signaling.
Collapse
|
16
|
Lai SW, Lin HJ, Liu YS, Yang LY, Lu DY. Monocarboxylate Transporter 4 Regulates Glioblastoma Motility and Monocyte Binding Ability. Cancers (Basel) 2020; 12:cancers12020380. [PMID: 32045997 PMCID: PMC7073205 DOI: 10.3390/cancers12020380] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 01/31/2020] [Accepted: 02/05/2020] [Indexed: 12/31/2022] Open
Abstract
Glioblastoma (GBM) is characterized by severe hypoxic and acidic stress in an abnormal microenvironment. Monocarboxylate transporter (MCT)4, a pH-regulating protein, plays an important role in pH homeostasis of the glycolytic metabolic pathways in cancer cells. The present study showed that GBM exposure to hypoxic conditions increased MCT4 expression. We further analyzed the glioma patient database and found that MCT4 was significantly overexpressed in patients with GBM, and the MCT4 levels positively correlated with the clinico-pathological grades of gliomas. We further found that MCT4 knockdown abolished the hypoxia-enhanced of GBM cell motility and monocyte adhesion. However, the overexpression of MCT4 promoted GBM cell migration and monocyte adhesion activity. Our results also revealed that MCT4-regulated GBM cell motility and monocyte adhesion are mediated by activation of the serine/threonine-specific protein kinase (AKT), focal adhesion kinase (FAK), and epidermal growth factor receptor (EGFR) signaling pathways. Moreover, hypoxia mediated the acetylated signal transducer and activator of transcription (STAT)3 expression and regulated the transcriptional activity of hypoxia inducible factor (HIF)-1α in GBM cell lines. In a GBM mouse model, MCT4 was significantly increased in the tumor necrotic tissues. These findings raise the possibility for the development of novel therapeutic strategies targeting MCT4.
Collapse
Affiliation(s)
- Sheng-Wei Lai
- Graduate Institute of Basic Medical Science, China Medical University, Taichung 40402, Taiwan;
| | - Hui-Jung Lin
- Department of Pharmacology, School of Medicine, China Medical University, Taichung 40402, Taiwan; (H.-J.L.); (Y.-S.L.)
| | - Yu-Shu Liu
- Department of Pharmacology, School of Medicine, China Medical University, Taichung 40402, Taiwan; (H.-J.L.); (Y.-S.L.)
| | - Liang-Yo Yang
- Department of Physiology, School of Medicine, China Medical University, Taichung 40402, Taiwan
- Laboratory for Neural Repair and Research Center for Biotechnology, China Medical University Hospital, Taichung 40447, Taiwan
- Correspondence: (L.-Y.Y.); (D.-Y.L.); Tel.: +886-4-2205-3366 (ext. 2253) (D.-Y.L.)
| | - Dah-Yuu Lu
- Department of Pharmacology, School of Medicine, China Medical University, Taichung 40402, Taiwan; (H.-J.L.); (Y.-S.L.)
- Department of Photonics and Communication Engineering, Asia University, Taichung 41354, Taiwan
- Correspondence: (L.-Y.Y.); (D.-Y.L.); Tel.: +886-4-2205-3366 (ext. 2253) (D.-Y.L.)
| |
Collapse
|
17
|
CRISPR, Prime Editing, Optogenetics, and DREADDs: New Therapeutic Approaches Provided by Emerging Technologies in the Treatment of Spinal Cord Injury. Mol Neurobiol 2020; 57:2085-2100. [DOI: 10.1007/s12035-019-01861-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 12/15/2019] [Indexed: 02/07/2023]
|
18
|
Cappoli N, Mezzogori D, Tabolacci E, Coletta I, Navarra P, Pani G, Dello Russo C. The mTOR kinase inhibitor rapamycin enhances the expression and release of pro-inflammatory cytokine interleukin 6 modulating the activation of human microglial cells. EXCLI JOURNAL 2019; 18:779-798. [PMID: 31645839 PMCID: PMC6806201 DOI: 10.17179/excli2019-1715] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 09/02/2019] [Indexed: 02/06/2023]
Abstract
Emerging evidence suggests the potential use of rapamycin in treatment of several neurological disorders. The drug readily crosses the blood brain barrier and may exert direct immunomodulatory effects within the brain. Microglia are the main innate immune cells of the brain, thus critically involved in the initiation and development of inflammatory processes at this level. However, there are conflicting data from rodent studies about the pharmacological effects of rapamycin on microglial inflammatory responses. Considering that rodent microglia display relevant biochemical and pharmacological differences compared to human microglia, in the present study we studied the effects of rapamycin in an experimental model of human microglia, the human microglial clone 3 (HMC3) cell line. Rapamycin was tested in the nM range both under basal conditions and in cells activated with a pro-inflammatory cytokine cocktail, consisting in a mixture of interferon-γ and interleukin-1β (II). The drug significantly increased II stimulatory effect on interleukin-6 (IL-6) expression and release in the HMC3 cells, while reducing the production of free oxygen radicals (ROS) both under basal conditions and in cells activated with II. Consistently with its known molecular mechanism of action, rapamycin reduced the extent of activation of the so-called 'mechanistic' target of rapamycin complex 1 (mTORC1) kinase and the total amount of intracellular proteins. In contrast to rodent cells, rapamycin did not alter human microglial cell viability nor inhibited cell proliferation. Moreover, rapamycin did not exert any significant effect on the morphology of the HMC3 cells. All together these data suggest that the inhibition of mTORC1 in human microglia by rapamycin results in complex immunomodulatory effects, including a significant increase in the expression and release of the pro-inflammatory IL-6.
Collapse
Affiliation(s)
- Natalia Cappoli
- Institute of Pharmacology, Università Cattolica del S. Cuore, Roma
| | - Daniele Mezzogori
- Institute of Human Physiology, Università Cattolica del S. Cuore, Roma
| | - Elisabetta Tabolacci
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma -Institute of Genomic Medicine, Università Cattolica del S. Cuore, Roma
| | - Isabella Coletta
- Angelini RR&D (Research, Regulatory & Development) - Angelini S.p.A
| | - Pierluigi Navarra
- Pharmacology Unit, Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma -Institute of Pharmacology, Università Cattolica del S. Cuore, Roma
| | - Giovambattista Pani
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma - Institute of General Pathology, Università Cattolica del S. Cuore, Roma
| | - Cinzia Dello Russo
- Pharmacology Unit, Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma -Institute of Pharmacology, Università Cattolica del S. Cuore, Roma
| |
Collapse
|
19
|
Butturini E, Boriero D, Carcereri de Prati A, Mariotto S. STAT1 drives M1 microglia activation and neuroinflammation under hypoxia. Arch Biochem Biophys 2019; 669:22-30. [PMID: 31121156 DOI: 10.1016/j.abb.2019.05.011] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 05/07/2019] [Accepted: 05/15/2019] [Indexed: 12/25/2022]
Abstract
Microglia are resident immune cells that act as the first active defence in the central nervous system. These cells constantly monitor the tissue microenvironment and rapidly react in response to hypoxia, infection and injuries. Hypoxia in the brain has been detected in several neurodegenerative disorders such as Alzheimer's disease, amyotrophic lateral sclerosis, Parkinson's disease and Huntington's disease. Hypoxic conditions activate microglia cells towards M1 phenotype resulting in oxidative stress and the release of pro-inflammatory cytokines. Recently, we have demonstrated that oxidative stress induces S-glutathionylation of the STAT1 and hyper-activates its signaling in microglia BV2 cells pointing out the importance of this transcription factor in neuroinflammation. In this paper we analyse the cellular mechanisms that drive M1 microglia activation in BV2 cells in response to hypoxia correlating it to STAT1 activation. The analysis of the molecular mechanism of STAT1 signaling reveals that hypoxia generates oxidative stress and induces both phosphorylation and S-glutathionylation of STAT1 that are responsible of its aberrant activation. The silencing of STAT1 protein expression counteracts hypoxia-M1 microglia phenotype suggesting the strong link between hypoxia-STAT1 and STAT1-microglia activation.
Collapse
Affiliation(s)
- Elena Butturini
- Department of Neuroscience, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, Verona, Italy.
| | - Diana Boriero
- Department of Neuroscience, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, Verona, Italy
| | - Alessandra Carcereri de Prati
- Department of Neuroscience, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, Verona, Italy
| | - Sofia Mariotto
- Department of Neuroscience, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, Verona, Italy
| |
Collapse
|
20
|
Ostrowski RP, Zhang JH. The insights into molecular pathways of hypoxia-inducible factor in the brain. J Neurosci Res 2018; 98:57-76. [PMID: 30548473 DOI: 10.1002/jnr.24366] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 11/16/2018] [Accepted: 11/20/2018] [Indexed: 12/12/2022]
Abstract
The objectives of this present work were to review recent developments on the role of hypoxia-inducible factor (HIF) in the survival of cells under normoxic versus hypoxic and inflammatory brain conditions. The dual nature of HIF effects appears well established, based on the accumulated evidence of HIF playing both the role of adaptive factor and mediator of cell demise. Cellular HIF responses depend on pathophysiological conditions, developmental phase, comorbidities, and administered medications. In addition, HIF-1α and HIF-2α actions may vary in the same tissues. The multiple roles of HIF in stem cells are emerging. HIF not only regulates expression of target genes and thereby influences resultant protein levels but also contributes to epigenetic changes that may reciprocally provide feedback regulations loops. These HIF-dependent alterations in neurological diseases and its responses to treatments in vivo need to be examined alongside with a functional status of subjects involved in such studies. The knowledge of HIF pathways might be helpful in devising HIF-mimetics and modulating drugs, acting on the molecular level to improve clinical outcomes, as exemplified here by clinical and experimental data of selected brain diseases, occasionally corroborated by the data from disorders of other organs. Because of complex role of HIF in brain injuries, prospective therapeutic interventions need to differentially target HIF responses depending on their roles in the molecular mechanisms of neurologic diseases.
Collapse
Affiliation(s)
- Robert P Ostrowski
- Department of Experimental and Clinical Neuropathology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
| | - John H Zhang
- Departments of Anesthesiology and Physiology, School of Medicine, Loma Linda University, Loma Linda, California
| |
Collapse
|
21
|
Tao L, Zhang L, Gao R, Jiang F, Cao J, Liu H. Andrographolide Alleviates Acute Brain Injury in a Rat Model of Traumatic Brain Injury: Possible Involvement of Inflammatory Signaling. Front Neurosci 2018; 12:657. [PMID: 30294256 PMCID: PMC6158349 DOI: 10.3389/fnins.2018.00657] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 09/03/2018] [Indexed: 12/17/2022] Open
Abstract
Neuroinflammation plays an important role in secondary injury after traumatic brain injury (TBI). Andrographolide (Andro), a diterpenoid lactone isolated from Andrographis paniculata, has been demonstrated to exhibit anti-inflammatory activity in neurodegenerative disorders. This study therefore aimed to investigate the potential neuroprotective effects of Andro after TBI and explore the underlying mechanisms. In our study, we used a weight-dropped model to induce TBI in Sprague–Dawley rats, the neurological deficits were assessed using modified neurological severity scores, Fluoro-Jade B (FJB) and terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling (TUNEL) staining were employed to examine neuronal degeneration and apoptosis after TBI, immunofluorescence was designed to investigate microglial activation. Quantitative Real-time PCR and ELISA were conducted to detect the expression levels of pro-inflammatory cytokines, Western blot was used to examine the expression level of proteins of relative signaling pathway. Our results showed that after Andro administration, the neurological deficit was attenuated, and the cerebral edema and apoptosis in brain tissues were also decreased following TBI. Both microglial activation and the expression of pro-inflammatory cytokines were significantly inhibited by Andro after TBI. Moreover, Andro inhibited NF-κB p65 subunit translocation and decreased the expression levels of phosphorylated extracellular signal regulated kinase (ERK) and p38 MAPK after TBI. Altogether, this study suggests that Andro could improve neurobehavioral function by inhibiting NF-κB and MAPK signaling pathway in TBI, which might provide a new approach for treating brain injury.
Collapse
Affiliation(s)
- Li Tao
- Department of Pharmacy and Translational Medicine Center, Zhangjiagang First People's Hospital, Suzhou, China
| | - Li Zhang
- Department of Neurosurgery, Zhangjiagang First People's Hospital, Suzhou, China
| | - Rong Gao
- Department of Neurosurgery, Zhangjiagang First People's Hospital, Suzhou, China
| | - Feng Jiang
- Department of Neurosurgery, Zhangjiagang First People's Hospital, Suzhou, China
| | - Jianbo Cao
- Department of Pharmacy and Translational Medicine Center, Zhangjiagang First People's Hospital, Suzhou, China
| | - Huixiang Liu
- Department of Neurosurgery, Zhangjiagang First People's Hospital, Suzhou, China
| |
Collapse
|
22
|
Zhou T, Yuan Z, Tan S, Jin Y, Yang Y, Shi H, Wang W, Niu D, Gao L, Jiang W, Gao D, Liu Z. A Review of Molecular Responses of Catfish to Bacterial Diseases and Abiotic Stresses. Front Physiol 2018; 9:1113. [PMID: 30210354 PMCID: PMC6119772 DOI: 10.3389/fphys.2018.01113] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Accepted: 07/25/2018] [Indexed: 12/11/2022] Open
Abstract
Catfish is one of the major aquaculture species in the United States. However, the catfish industry is threatened by several bacterial diseases such as enteric septicemia of catfish (ESC), columnaris disease and Aeromonas disease, as well as by abiotic stresses such as high temperature and low oxygen. Research has been conducted for several decades to understand the host responses to these diseases and abiotic stresses. With the development of sequencing technologies, and the application of genome-wide association studies in aquaculture species, significant progress has been made. This review article summarizes recent progress in understanding the molecular responses of catfish after bacterial infection and stress challenges, and in understanding of genomic and genetic basis for disease resistance and stress tolerance.
Collapse
Affiliation(s)
- Tao Zhou
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, United States
| | - Zihao Yuan
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, United States
| | - Suxu Tan
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, United States
| | - Yulin Jin
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, United States
| | - Yujia Yang
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, United States
| | - Huitong Shi
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, United States
| | - Wenwen Wang
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, United States
| | - Donghong Niu
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, United States
| | - Lei Gao
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, United States
| | - Wansheng Jiang
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, United States
| | - Dongya Gao
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, United States
| | - Zhanjiang Liu
- Department of Biology, College of Art and Sciences, Syracuse University, Syracuse, NY, United States
| |
Collapse
|
23
|
Hypoxic Signaling and Cholesterol Lipotoxicity in Fatty Liver Disease Progression. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:2548154. [PMID: 29955245 PMCID: PMC6000860 DOI: 10.1155/2018/2548154] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 04/30/2018] [Accepted: 05/14/2018] [Indexed: 02/06/2023]
Abstract
Cholesterol is the only lipid whose absorption in the gastrointestinal tract is limited by gate-keeping transporters and efflux mechanisms, preventing its rapid absorption and accumulation in the liver and blood vessels. In this review, I explored the current data regarding cholesterol accumulation in liver cells and key mechanisms in cholesterol-induced fatty liver disease associated with the activation of deleterious hypoxic and nitric oxide signal transduction pathways. Although nonalcoholic fatty liver disease (NAFLD) affects both obese and nonobese individuals, the mechanism of NAFLD progression in lean individuals with healthy metabolism is puzzling. Lean NAFLD individuals exhibit normal metabolic responses, implying that liver damage is not associated with impaired metabolism per se and that direct lipotoxic effects are crucial for disease progression. Several redox and oxidant signaling pathways involving cholesterol are at play in fatty liver disease development. These include impairment of the mitochondrial and lysosomal function by cholesterol loading of the inner-cell membranes; formation of cholesterol crystals and hepatocyte degradation; and crown-like structures surrounding degrading hepatocytes, activating Kupffer cells, and evoking inflammation. The current review focuses on the induction of liver inflammation, fibrosis, and steatosis by free cholesterol via the hypoxia-inducible factor 1α (HIF-1α), a main oxygen-sensing transcription factor involved in all stages of NAFLD. Cholesterol loading in hepatocytes can result in chronic HIF-1α activity because of the decreased oxygen availability and excessive production of nitric oxide and mitochondrial reactive oxygen species.
Collapse
|
24
|
Luo XQ, Li A, Yang X, Xiao X, Hu R, Wang TW, Dou XY, Yang DJ, Dong Z. Paeoniflorin exerts neuroprotective effects by modulating the M1/M2 subset polarization of microglia/macrophages in the hippocampal CA1 region of vascular dementia rats via cannabinoid receptor 2. Chin Med 2018; 13:14. [PMID: 29560022 PMCID: PMC5859430 DOI: 10.1186/s13020-018-0173-1] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 03/13/2018] [Indexed: 02/07/2023] Open
Abstract
Background Cerebral hypoperfusion is a pivotal risk factor for vascular dementia (VD), for which effective therapy remains inadequate. Persistent inflammatory responses and excessive chemotaxis of microglia/macrophages in the brain may accelerate the progression of VD. Endocannabinoids are involved in neuronal protection against inflammation-induced neuronal injury. Cannabinoids acting at cannabinoid receptor 2 (CB2R) can decrease inflammation. Based on the identification of paeoniflorin (PF) as a CB2R agonist, we investigated the neuroprotective and microglia/macrophages M1 to M2 polarization promoting effects of PF in a permanent four-vessel occlusion rat model. Methods One week after surgery, PF was intraperitoneally administered at a dose of 40 mg/kg once a day for 28 successive days. The effects of PF on memory deficit were investigated by a Morris water maze test, and the effects of PF on hippocampal neuronal damage were evaluated by light microscope and electron microscope. The mRNA and protein expression levels of key molecules related to the M1/M2 polarization of microglia/macrophages were assessed by RT-qPCR and Western blotting, respectively. Results Administration of PF could significantly attenuate cerebral hypoperfusion-induced impairment of learning and memory and reduce the morphological and ultrastructural changes in the hippocampal CA1 region of rats. Moreover, PF promoted an M1 to M2 phenotype transition in microglia/macrophages in the hippocampus of rats. In addition to its inhibitory property against proinflammatory M1 mediator expression, such as IL-1β, IL-6, TNF-α and NO, PF dramatically up-regulated expression of anti-inflammatory cytokines IL-10 and TGF-β1. Importantly, CB2R antagonist AM630 abolished these beneficial effects produced by PF on learning, memory and hippocampus structure in rats, as well as the polarization of microglia/macrophages to the M2 phenotype. Additionally, PF treatment significantly inhibited cerebral hypoperfusion-induced mTOR/NF-κB proinflammatory pathway and enhanced PI3K/Akt anti-inflammatory pathway. Effects of PF on these signaling pathways were effectively attenuated when rats were co-treated with PF and AM630, indicating that the mTOR/NF-κB and PI3K/Akt signaling pathways were involved in the PF effects through CB2R activation. Conclusion These findings demonstrated PF exerts its neuroprotective effect and shifts the inflammatory milieu toward resolution by modulation of microglia/macrophage polarization via CB2R activation. Electronic supplementary material The online version of this article (10.1186/s13020-018-0173-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Xian-Qin Luo
- 1Chongqing Key Laboratory of Biochemistry and Molecular Pharmacology, School of Pharmacy, Chongqing Medical University, Chongqing, 400016 China
| | - Ao Li
- 2College of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, 400054 China
| | - Xue Yang
- 3Institute of Chinese Pharmacology and Toxicology, Chongqing Academy of Chinese Materia Medica, Chongqing, 400065 China
| | - Xiao Xiao
- 2College of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, 400054 China
| | - Rong Hu
- Drug Review Section, China Chongqing Technical Center for Drug Evaluation and Certification, Chongqing, 400014 China
| | - Tian-Wen Wang
- 3Institute of Chinese Pharmacology and Toxicology, Chongqing Academy of Chinese Materia Medica, Chongqing, 400065 China
| | - Xiao-Yun Dou
- 5Institute of Life Sciences, Chongqing Medical University, Chongqing, 400016 China
| | - Da-Jian Yang
- 3Institute of Chinese Pharmacology and Toxicology, Chongqing Academy of Chinese Materia Medica, Chongqing, 400065 China
| | - Zhi Dong
- 1Chongqing Key Laboratory of Biochemistry and Molecular Pharmacology, School of Pharmacy, Chongqing Medical University, Chongqing, 400016 China
| |
Collapse
|
25
|
Bok S, Kim YE, Woo Y, Kim S, Kang SJ, Lee Y, Park SK, Weissman IL, Ahn GO. Hypoxia-inducible factor-1α regulates microglial functions affecting neuronal survival in the acute phase of ischemic stroke in mice. Oncotarget 2017; 8:111508-111521. [PMID: 29340071 PMCID: PMC5762339 DOI: 10.18632/oncotarget.22851] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 11/16/2017] [Indexed: 01/12/2023] Open
Abstract
Cells universally adapt to ischemic conditions by turning on a transcription factor hypoxia-inducible factor (HIF), in which its role is known to differ widely across many different types of cells. Given that microglia have been reported as an essential mediator of neuroinflammation in many brain diseases, we examined the role of HIF in microglia in the progression of an acute phase of ischemic stroke by challenging our novel strains of myeloid-specific Hif-1α or Hif-2α knockout (KO) mice created by Cre-loxP system via middle cerebral artery occlusion (MCAO). We observed that Hif-1α but not Hif-2α KO mice exhibited an improved recovery compared to wild-type (WT) mice determined by behavioral tests. Immunostaining analyses revealed that there were increased numbers of both mature and immature neurons while microglia and apoptotic cells were significantly decreased in the dentate gyrus of Hif-1α KO mice following MCAO. By isolating microglia with fluorescence-activated cell sorter, we found that HIF-1α-deficient microglia were impaired in phagocytosis, reactive oxygen species (ROS) production, and tumor necrosis factor-α (TNF-α) secretion. We further observed a significant decrease in the expression of Cd36 and milk fat globule-epidermal growth factor 8 (Mfg-e8) genes, both of which contain hypoxia-responsive element (HRE). Knocking down either of these genes in BV2 microglial cells was sufficient to abrogate HIF-mediated increase in phagocytosis, production of intracellular ROS, or TNF-α secretion. Our results therefore suggest that HIF-1α in microglia is a novel therapeutic target to protect neuronal survival following an acute phase of ischemic stroke.
Collapse
Affiliation(s)
- Seoyeon Bok
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea.,Current/Present address: Department of Radiation Oncology, Yonsei University College of Medicine, Yonsei University Health System, Seoul 03722, Korea
| | - Young-Eun Kim
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Youngsik Woo
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Soeun Kim
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Suk-Jo Kang
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Yoontae Lee
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Sang Ki Park
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Irving L Weissman
- Stem Cell Institute and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - G-One Ahn
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| |
Collapse
|
26
|
de Oliveira GA, Cheng RYS, Ridnour LA, Basudhar D, Somasundaram V, McVicar DW, Monteiro HP, Wink DA. Inducible Nitric Oxide Synthase in the Carcinogenesis of Gastrointestinal Cancers. Antioxid Redox Signal 2017; 26:1059-1077. [PMID: 27494631 PMCID: PMC5488308 DOI: 10.1089/ars.2016.6850] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
SIGNIFICANCE Gastrointestinal (GI) cancer taken together constitutes one of the most common cancers worldwide with a broad range of etiological mechanisms. In this review, we have examined the impact of nitric oxide (NO) on the etiology of colon, colorectal, gastric, esophageal, and liver cancers. Recent Advances: Despite differences in etiology, initiation, and progression, chronic inflammation has been shown to be a common element within these cancers showing interactions of numerous pathways. NO generated at the inflammatory site contributes to the initiation and progression of disease. The amount of NO generated, time, and site vary and are an important determinant of the biological effects initiated. Among the nitric oxide synthase enzymes, the inducible isoform has the most diverse range, participating in numerous carcinogenic processes. There is emerging evidence showing that inducible nitric oxide synthase (NOS2) plays a central role in the process of tumor initiation and/or development. CRITICAL ISSUES Redox inflammation through NOS2 and cyclooxygenase-2 participates in driving the mechanisms of initiation and progression in GI cancers. FUTURE DIRECTIONS Understanding the underlying mechanism involved in NOS2 activation can provide new insights into important prevention and treatment strategies. Antioxid. Redox Signal. 26, 1059-1077.
Collapse
Affiliation(s)
- Graciele Almeida de Oliveira
- 1 Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Frederick, Maryland
| | - Robert Y S Cheng
- 1 Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Frederick, Maryland
| | - Lisa A Ridnour
- 1 Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Frederick, Maryland
| | - Debashree Basudhar
- 1 Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Frederick, Maryland
| | - Veena Somasundaram
- 1 Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Frederick, Maryland
| | - Daniel W McVicar
- 1 Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Frederick, Maryland
| | - Hugo Pequeno Monteiro
- 2 Laboratório de Sinalização Celular, Universidade Federal de São Paulo , São Paulo, Brazil
| | - David A Wink
- 1 Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Frederick, Maryland
| |
Collapse
|
27
|
Tan WSD, Liao W, Zhou S, Wong WSF. Is there a future for andrographolide to be an anti-inflammatory drug? Deciphering its major mechanisms of action. Biochem Pharmacol 2017; 139:71-81. [PMID: 28377280 DOI: 10.1016/j.bcp.2017.03.024] [Citation(s) in RCA: 114] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 03/30/2017] [Indexed: 11/18/2022]
Abstract
Andrographis paniculata has long been part of the traditional herbal medicine system in Asia and in Scandinavia. Andrographolide was isolated as a major bioactive constituent of A. paniculata in 1951, and since 1984, andrographolide and its analogs have been scrutinized with modern drug discovery approach for anti-inflammatory properties. With this accumulated wealth of pre-clinical data, it is imperative to review and consolidate different sources of information, to decipher the major anti-inflammatory mechanisms of action in inflammatory diseases, and to provide direction for future studies. Andrographolide and its analogs have been shown to provide anti-inflammatory benefits in a variety of inflammatory disease models. Among the diverse signaling pathways investigated, inhibition of NF-κB activity is the prevailing anti-inflammatory mechanism elicited by andrographolide. There is also increasing evidence supporting endogenous antioxidant defense enhancement by andrographolide through Nrf2 activation. However, the exact pathway leading to NF-κB and Nrf2 activation by andrographolide has yet to be elucidated. Validation and consensus on the major mechanistic actions of andrographolide in different inflammatory conditions are required before translating current findings into clinical settings. There are a few clinical trials conducted using andrographolide in fixed combination formulation which have shown anti-inflammatory benefits and good safety profile. A concerted effort is definitely needed to identify potent andrographolide lead compounds with improved pharmacokinetics and toxicological properties. Taken together, andrographolide and its analogs have great potential to be the next new class of anti-inflammatory agents, and more andrographolide molecules are likely moving towards clinical study stage in the near future.
Collapse
MESH Headings
- Animals
- Anti-Inflammatory Agents, Non-Steroidal/adverse effects
- Anti-Inflammatory Agents, Non-Steroidal/chemistry
- Anti-Inflammatory Agents, Non-Steroidal/pharmacology
- Anti-Inflammatory Agents, Non-Steroidal/therapeutic use
- Autoimmune Diseases/drug therapy
- Autoimmune Diseases/immunology
- Autoimmune Diseases/metabolism
- Autoimmune Diseases/prevention & control
- Chemical and Drug Induced Liver Injury/immunology
- Chemical and Drug Induced Liver Injury/metabolism
- Chemical and Drug Induced Liver Injury/prevention & control
- Dermatitis/drug therapy
- Dermatitis/immunology
- Dermatitis/metabolism
- Dermatitis/prevention & control
- Diterpenes/adverse effects
- Diterpenes/chemistry
- Diterpenes/pharmacology
- Diterpenes/therapeutic use
- Drug Design
- Drugs, Investigational/adverse effects
- Drugs, Investigational/chemistry
- Drugs, Investigational/pharmacology
- Drugs, Investigational/therapeutic use
- Hepatitis/drug therapy
- Hepatitis/immunology
- Hepatitis/metabolism
- Hepatitis/prevention & control
- Humans
- Hypoxia-Inducible Factor 1, alpha Subunit/antagonists & inhibitors
- Hypoxia-Inducible Factor 1, alpha Subunit/metabolism
- Liver Cirrhosis/drug therapy
- Liver Cirrhosis/immunology
- Liver Cirrhosis/metabolism
- Liver Cirrhosis/prevention & control
- Models, Biological
- NF-E2-Related Factor 2/agonists
- NF-E2-Related Factor 2/metabolism
- NF-kappa B p50 Subunit/antagonists & inhibitors
- NF-kappa B p50 Subunit/chemistry
- NF-kappa B p50 Subunit/metabolism
- Neurodegenerative Diseases/drug therapy
- Neurodegenerative Diseases/immunology
- Neurodegenerative Diseases/metabolism
- Neurodegenerative Diseases/prevention & control
- Oxidative Stress/drug effects
- Pneumonia/drug therapy
- Pneumonia/immunology
- Pneumonia/metabolism
- Protective Agents/chemistry
- Protective Agents/metabolism
- Protective Agents/therapeutic use
- Signal Transduction/drug effects
Collapse
Affiliation(s)
- W S Daniel Tan
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University Health System, 16 Medical Drive, Singapore 117600, Singapore
| | - Wupeng Liao
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University Health System, 16 Medical Drive, Singapore 117600, Singapore
| | - Shuo Zhou
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University Health System, 16 Medical Drive, Singapore 117600, Singapore
| | - W S Fred Wong
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University Health System, 16 Medical Drive, Singapore 117600, Singapore; Immunology Program, Life Science Institute, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore.
| |
Collapse
|
28
|
Kiernan EA, Smith SMC, Mitchell GS, Watters JJ. Mechanisms of microglial activation in models of inflammation and hypoxia: Implications for chronic intermittent hypoxia. J Physiol 2017; 594:1563-77. [PMID: 26890698 DOI: 10.1113/jp271502] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Accepted: 01/16/2016] [Indexed: 12/12/2022] Open
Abstract
Chronic intermittent hypoxia (CIH) is a hallmark of sleep apnoea, a condition associated with diverse clinical disorders. CIH and sleep apnoea are characterized by increased reactive oxygen species formation, peripheral and CNS inflammation, neuronal death and neurocognitive deficits. Few studies have examined the role of microglia, the resident CNS immune cells, in models of CIH. Thus, little is known concerning their direct contributions to neuropathology or the cellular mechanisms regulating their activities during or following pathological CIH. In this review, we identify gaps in knowledge regarding CIH-induced microglial activation, and propose mechanisms based on data from related models of hypoxia and/or hypoxia-reoxygenation. CIH may directly affect microglia, or may have indirect effects via the periphery or other CNS cells. Peripheral inflammation may indirectly activate microglia via entry of pro-inflammatory molecules into the CNS, and/or activation of vagal afferents that trigger CNS inflammation. CIH-induced release of damage-associated molecular patterns from injured CNS cells may also activate microglia via interactions with pattern recognition receptors expressed on microglia. For example, Toll-like receptors activate mitogen-activated protein kinase/transcription factor pathways required for microglial inflammatory gene expression. Although epigenetic effects from CIH have not yet been studied in microglia, potential epigenetic mechanisms in microglial regulation are discussed, including microRNAs, histone modifications and DNA methylation. Epigenetic effects can occur during CIH, or long after it has ended. A better understanding of CIH effects on microglial activities may be important to reverse CIH-induced neuropathology in patients with sleep disordered breathing.
Collapse
Affiliation(s)
- Elizabeth A Kiernan
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Stephanie M C Smith
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Gordon S Mitchell
- Department of Physical Therapy, University of Florida, Gainesville, FL, 32610, USA
| | - Jyoti J Watters
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53706, USA
| |
Collapse
|
29
|
Shi Q, Liu X, Wang N, Zheng X, Ran J, Liu Z, Fu J, Zheng J. 1400W ameliorates acute hypobaric hypoxia/reoxygenation-induced cognitive deficits by suppressing the induction of inducible nitric oxide synthase in rat cerebral cortex microglia. Behav Brain Res 2016; 319:188-199. [PMID: 27888018 DOI: 10.1016/j.bbr.2016.11.039] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 10/18/2016] [Accepted: 11/21/2016] [Indexed: 01/04/2023]
Abstract
Nitric oxide (NO) is involved in neuronal modifications, and overproduction of NO contributes to memory deficits after acute hypobaric hypoxia-reoxygenation. This study investigated the ability of the iNOS inhibitor 1400W to counteract spatial memory deficits following acute hypobaric hypoxia-reoxygenation, and to affect expression of NOS, NO, 3-NT and MDA production, and apoptosis in rat cerebral cortex. We also used primary rat microglia to investigate the effect of 1400W on expression of NOS, NO, 3-NT and MDA production, and apoptosis. Acute hypobaric hypoxia-reoxygenation impaired spatial memory, and was accompanied by activated microglia, increased iNOS expression, NO, 3-NT and MDA production, and neuronal cell apoptosis in rat cerebral cortex one day post-reoxygenation. 1400W treatment inhibited iNOS expression without affecting nNOS or eNOS. 1400W also reduced NO, 3-NT and MDA production, and prevented neuronal cell apoptosis in cerebral cortex, in addition to reversing spatial memory impairment after acute hypobaric hypoxia-reoxygenation. Hypoxia-reoxygenation activated primary microglia, and increased iNOS and nNOS expression, NO, 3-NT, and MDA production, and apoptosis. Treatment with 1400W inhibited iNOS expression without affecting nNOS, reduced NO, 3-NT and MDA production, and prevented apoptosis in primary microglia. Based on the above findings, we concluded that the highly selective iNOS inhibitor 1400W inhibited iNOS induction in microglial cells, and reduced generation of NO, thereby mitigating oxidative stress and neuronal cell apoptosis in the rat cerebral cortex, and improving the spatial memory dysfunction caused by acute hypobaric hypoxia-reoxygenation.
Collapse
Affiliation(s)
- Qinghai Shi
- Medical Research Center, Southwest Hospital, Third Military Medical University, Chongqing 400038, China; Clinical Laboratory Diagnostic Center, General Hospital of Xinjiang Military Region, Urumqi 830000, Xinjiang, China
| | - Xin Liu
- Medical Research Center, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
| | - Ning Wang
- Medical Research Center, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
| | - Xinchuan Zheng
- Medical Research Center, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
| | - Jihua Ran
- Clinical Laboratory Diagnostic Center, General Hospital of Xinjiang Military Region, Urumqi 830000, Xinjiang, China
| | - Zhengxiang Liu
- Clinical Laboratory Diagnostic Center, General Hospital of Xinjiang Military Region, Urumqi 830000, Xinjiang, China
| | - Jianfeng Fu
- Clinical Laboratory Diagnostic Center, General Hospital of Xinjiang Military Region, Urumqi 830000, Xinjiang, China
| | - Jiang Zheng
- Medical Research Center, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.
| |
Collapse
|
30
|
Hypoxic Adaptation in the Nervous System: Promise for Novel Therapeutics for Acute and Chronic Neurodegeneration. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 903:221-43. [PMID: 27343100 DOI: 10.1007/978-1-4899-7678-9_16] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Homeostasis is the process by which cells adapt to stress and prevent or repair injury. Unique programs have evolved to sense and activate these homeostatic mechanisms and as such, homeostatic sensors may be potent therapeutic targets. The hypoxic response mediated by hypoxia inducible factor (HIF) downstream of oxygen sensing by HIF prolyl 4-hydroxylases (PHDs) has been well-studied, revealing cell-type specific regulation of HIF stability, activity, and transcriptional targets. HIF's paradoxical roles in nervous system development, physiology, and pathology arise from its complex roles in hypoxic adaptation and normoxic biology. Understanding how to engage the hypoxic response so as to recapitulate the protective mechanism of ischemic preconditioning is a high priority. Indeed, small molecules that activate the hypoxic response provide broad neuroprotection in several clinically relevant injury models. Screens for PHD inhibitors have identified novel therapeutics for neuroprotection that are ready to proceed to clinical trials for ischemic stroke. Better understanding the mechanisms of how to engage hypoxic adaption without altering development or physiology may identify additional novel therapeutic targets for diverse acute and chronic neuropathologies.
Collapse
|
31
|
van Tilborg E, Heijnen CJ, Benders MJ, van Bel F, Fleiss B, Gressens P, Nijboer CH. Impaired oligodendrocyte maturation in preterm infants: Potential therapeutic targets. Prog Neurobiol 2015; 136:28-49. [PMID: 26655283 DOI: 10.1016/j.pneurobio.2015.11.002] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 11/02/2015] [Accepted: 11/18/2015] [Indexed: 12/20/2022]
Abstract
Preterm birth is an evolving challenge in neonatal health care. Despite declining mortality rates among extremely premature neonates, morbidity rates remain very high. Currently, perinatal diffuse white matter injury (WMI) is the most commonly observed type of brain injury in preterm infants and has become an important research area. Diffuse WMI is associated with impaired cognitive, sensory and psychological functioning and is increasingly being recognized as a risk factor for autism-spectrum disorders, ADHD, and other psychological disturbances. No treatment options are currently available for diffuse WMI and the underlying pathophysiological mechanisms are far from being completely understood. Preterm birth is associated with maternal inflammation, perinatal infections and disrupted oxygen supply which can affect the cerebral microenvironment by causing activation of microglia, astrogliosis, excitotoxicity, and oxidative stress. This intricate interplay of events negatively influences oligodendrocyte development, causing arrested oligodendrocyte maturation or oligodendrocyte cell death, which ultimately results in myelination failure in the developing white matter. This review discusses the current state in perinatal WMI research, ranging from a clinical perspective to basic molecular pathophysiology. The complex regulation of oligodendrocyte development in healthy and pathological conditions is described, with a specific focus on signaling cascades that may play a role in WMI. Furthermore, emerging concepts in the field of WMI and issues regarding currently available animal models are put forward. Novel insights into the molecular mechanisms underlying impeded oligodendrocyte maturation in diffuse WMI may aid the development of novel treatment options which are desperately needed to improve the quality-of-life of preterm neonates.
Collapse
Affiliation(s)
- Erik van Tilborg
- Laboratory of Neuroimmunology and Developmental Origins of Disease, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Cobi J Heijnen
- Laboratory of Neuroimmunology, Department of Symptom Research, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Manon J Benders
- Department of Neonatology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Frank van Bel
- Department of Neonatology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Bobbi Fleiss
- Inserm, Paris U1141, France; Université Paris Diderot, Sorbonne Paris Cité, UMRS, Paris 1141, France; Centre for the Developing Brain, Department of Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, United Kingdom
| | - Pierre Gressens
- Inserm, Paris U1141, France; Université Paris Diderot, Sorbonne Paris Cité, UMRS, Paris 1141, France; Centre for the Developing Brain, Department of Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, United Kingdom
| | - Cora H Nijboer
- Laboratory of Neuroimmunology and Developmental Origins of Disease, University Medical Center Utrecht, Utrecht, The Netherlands.
| |
Collapse
|
32
|
Radix Scrophulariae extracts (harpagoside) suppresses hypoxia-induced microglial activation and neurotoxicity. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 15:324. [PMID: 26370415 PMCID: PMC4570756 DOI: 10.1186/s12906-015-0842-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 09/01/2015] [Indexed: 01/13/2023]
Abstract
Background Hypoxia could lead to microglia activation and inflammatory mediators’ overproduction. These inflammatory molecules could amplify the neuroinflammatory process and exacerbate neuronal injury. The aim of this study is to find out whether harpagoside could reduce hypoxia-induced microglia activation. Methods In this study, primary microglia cells harvested from neonatal ICR mice were activated by exposure to hypoxia (1 % O2 for 3 h). Harpagoside had been shown to be no cytotoxicity on microglia cells by MTT assay. The scavenger effect of harpagoside on hypoxia-enhanced microglial cells proliferation, associated inflammatory genes expression (COX-II, IL-1β and IL-6 genes) and NO synthesis were also examined. Results Hypoxia enhances active proliferation of microglial cells, while harpagoside can scavenge this effect. We find that harpagoside could scavenge hypoxia-enhanced inflammatory genes expression (COX-2, IL-1β and IL-6 genes) and NO synthesis of microglial cells. Under 3 h’ hypoxic stimulation, the nuclear contents of p65 and hypoxia inducible factor-1α (HIF-1α) significantly increase, while the cytosol IκB-α content decreases; these effects can be reversed by 1 h’s pre-incubation of 10−8 M harpagoside. Harpagoside could decrease IκB-α protein phosphorylation and inhibit p65 protein translocation from the cytosol to the nucleus, thus suppress NF-κB activation and reduce the HIF-1α generation. Conclusion These results suggested that the anti-inflammatory mechanism of harpagoside might be associated with the NF-κB signaling pathway. Harpagoside protect against hypoxia-induced toxicity on microglial cells through HIF-α pathway.
Collapse
|
33
|
Verheijden S, Beckers L, Casazza A, Butovsky O, Mazzone M, Baes M. Identification of a chronic non-neurodegenerative microglia activation state in a mouse model of peroxisomal β-oxidation deficiency. Glia 2015; 63:1606-20. [PMID: 25846981 DOI: 10.1002/glia.22831] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 03/09/2015] [Accepted: 03/17/2015] [Indexed: 12/20/2022]
Abstract
The functional diversity and molecular adaptations of reactive microglia in the chronically inflamed central nervous system (CNS) are poorly understood. We previously showed that mice lacking multifunctional protein 2 (MFP2), a pivotal enzyme in peroxisomal β-oxidation, persistently accumulate reactive myeloid cells in the gray matter of the CNS. Here, we show that the increased numbers of myeloid cells solely derive from the proliferation of resident microglia and not from infiltrating monocytes. We defined the signature of Mfp2(-/-) microglia by gene expression profiling after acute isolation, which was validated by quantitative polymerase reaction (qPCR), immunohistochemical, and flow cytometric analysis. The features of Mfp2(-/-) microglia were compared with those from SOD1(G93A) mice, an amyotrophic lateral sclerosis model. In contrast to the neurodegenerative milieu of SOD1(G93A) spinal cord, neurons were intact in Mfp2(-/-) brain and Mfp2(-/-) microglia lacked signs of phagocytic and neurotoxic activity. The chronically reactive state of Mfp2(-/-) microglia was accompanied by the downregulation of markers that specify the unique microglial signature in homeostatic conditions. In contrast, mammalian target of rapamycin (mTOR) and downstream glycolytic and protein translation pathways were induced, indicative of metabolic adaptations. Mfp2(-/-) microglia were immunologically activated but not polarized to a pro- or anti-inflammatory phenotype. A peripheral lipopolysaccharide challenge provoked an exaggerated inflammatory response in Mfp2(-/-) brain, consistent with a primed state. Taken together, we demonstrate that chronic activation of resident microglia does not necessarily lead to phagocytosis nor overt neurotoxicity.
Collapse
Affiliation(s)
- Simon Verheijden
- Department of Pharmaceutical and Pharmacological Sciences, KU Leuven-University of Leuven, Cell Metabolism, Leuven, Belgium
| | - Lien Beckers
- Department of Pharmaceutical and Pharmacological Sciences, KU Leuven-University of Leuven, Cell Metabolism, Leuven, Belgium
| | - Andrea Casazza
- Department of Oncology, Laboratory of Molecular Oncology and Angiogenesis, KU Leuven-University of Leuven, Leuven, Belgium.,Laboratory of Molecular Oncology and Angiogenesis, VIB, Vesalius Research Center, Leuven, Belgium
| | - Oleg Butovsky
- Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Massimiliano Mazzone
- Department of Oncology, Laboratory of Molecular Oncology and Angiogenesis, KU Leuven-University of Leuven, Leuven, Belgium.,Laboratory of Molecular Oncology and Angiogenesis, VIB, Vesalius Research Center, Leuven, Belgium
| | - Myriam Baes
- Department of Pharmaceutical and Pharmacological Sciences, KU Leuven-University of Leuven, Cell Metabolism, Leuven, Belgium
| |
Collapse
|
34
|
Hypoxia-inducible factor-1α upregulation in microglia following hypoxia protects against ischemia-induced cerebral infarction. Neuroreport 2015; 25:1122-8. [PMID: 25089804 DOI: 10.1097/wnr.0000000000000236] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Activated microglia were considered to be the toxic inflammatory mediators that induce neuron degeneration after brain ischemia. Hypoxia can enhance the expression of hypoxia-inducible factor-1α (HIF-1α) in microglia and cause microglial activation. However, intermittent hypoxia has been reported recently to be capable of protecting the body from myocardial ischemia. We established a high-altitude environment as the hypoxic condition in this study. The hypoxic condition displayed a neuroprotective effect after brain ischemia, and mice exposed to this condition presented better neurological performance and smaller infarct size. At the same time, a high level of HIF-1α, low level of isoform of nitric oxide synthase, and a reduction in microglial activation were also seen in ischemic focus of hypoxic mice. However, this neuroprotective effect could be blocked by 2-methoxyestradiol, the HIF-1α inhibitor. Our finding suggested that HIF-1α expression was involved in microglial activation in vitro and was regulated by oxygen supply. The microglia were inactivated by re-exposure to hypoxia, which might be due to overexpression of HIF-1α. These results indicated that hypoxic conditions can be exploited to achieve maximum neuroprotection after brain ischemia. This mechanism possibly lies in microglial inactivation through regulation of the expression of HIF-1α.
Collapse
|
35
|
Xu L, Li Y, Fu Q, Ma S. Perillaldehyde attenuates cerebral ischemia-reperfusion injury-triggered overexpression of inflammatory cytokines via modulating Akt/JNK pathway in the rat brain cortex. Biochem Biophys Res Commun 2014; 454:65-70. [PMID: 25445600 DOI: 10.1016/j.bbrc.2014.10.025] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 10/07/2014] [Indexed: 11/17/2022]
Abstract
Perillaldehyde (PAH), one of the major oil components in Perilla frutescens, has anti-inflammatory effects. Few studies have examined the neuroprotective effect of PAH on stroke. So the aim of our study is to investigate the effect of PAH on ischemia-reperfusion-induced injury in the rat brain cortex. Middle cerebral artery occlusion (MCAO) model was selected to make cerebral ischemia-reperfusion injury. Rats were assigned randomly to groups of sham, MCAO, and two treatment groups by PAH at 36.0, 72.0mg/kg. Disease model was set up after intragastrically (i.g.) administering for 7 consecutive days. The neurological deficit, the cerebral infarct size, biochemical parameters and the relative mRNA and protein levels were examined. The results showed that the NO level, the iNOS activity, the neurological deficit scores, the cerebral infarct size and the expression of inflammatory cytokines including interleukin (IL)-1β, interleukin (IL)-6 and tumor necrosis factor (TNF)-α were significantly decreased by PAH treatment. PAH also increased the Phospho-Akt level and decrease the Phospho-JNK level by Western blot analysis. Meanwhile, the PAH groups exhibited a dramatically decrease of apoptosis-related mRNA expression such as Bax and caspase-3. Our findings shown that PAH attenuates cerebral ischemia/reperfusion injury in the rat brain cortex, and suggest its neuroprotective effect is relate to regulating the inflammatory response through Akt /JNK pathway. The activation of this signalling pathway eventually inhibits apoptotic cell death induced by cerebral ischemia-reperfusion.
Collapse
Affiliation(s)
- Lixing Xu
- Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing 210009, PR China
| | - Yuebi Li
- Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing 210009, PR China
| | - Qiang Fu
- Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing 210009, PR China.
| | - Shiping Ma
- Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing 210009, PR China.
| |
Collapse
|
36
|
Amiel E, Everts B, Fritz D, Beauchamp S, Ge B, Pearce EL, Pearce EJ. Mechanistic target of rapamycin inhibition extends cellular lifespan in dendritic cells by preserving mitochondrial function. THE JOURNAL OF IMMUNOLOGY 2014; 193:2821-30. [PMID: 25108022 DOI: 10.4049/jimmunol.1302498] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
TLR-mediated activation of dendritic cells (DCs) is associated with a metabolic transition in which mitochondrial oxidative phosphorylation is inhibited by endogenously synthesized NO and the cells become committed to glucose and aerobic glycolysis for survival. We show that inhibition of mechanistic target of rapamycin (mTOR) extends the lifespan of TLR-activated DCs by inhibiting the induction of NO production, thereby allowing the cells to continue to use their mitochondria to generate ATP, and allowing them the flexibility to use fatty acids or glucose as nutrients to fuel core metabolism. These data provide novel mechanistic insights into how mTOR modulates DC metabolism and cellular longevity following TLR activation and provide an explanation for previous findings that mTOR inhibition enhances the efficacy of DCs in autologous vaccination.
Collapse
Affiliation(s)
- Eyal Amiel
- Department of Medical Laboratory and Radiation Sciences, College of Nursing and Health Sciences, University of Vermont, Burlington, VT 05405; Trudeau Institute, Saranac Lake, NY 12983; and
| | - Bart Everts
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Daniel Fritz
- Department of Medical Laboratory and Radiation Sciences, College of Nursing and Health Sciences, University of Vermont, Burlington, VT 05405
| | - Saritha Beauchamp
- Department of Medical Laboratory and Radiation Sciences, College of Nursing and Health Sciences, University of Vermont, Burlington, VT 05405
| | - Burong Ge
- Department of Medical Laboratory and Radiation Sciences, College of Nursing and Health Sciences, University of Vermont, Burlington, VT 05405
| | - Erika L Pearce
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Edward J Pearce
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| |
Collapse
|
37
|
Xie R, Wang P, Cheng M, Sapolsky R, Ji X, Zhao H. Mammalian target of rapamycin cell signaling pathway contributes to the protective effects of ischemic postconditioning against stroke. Stroke 2014; 45:2769-76. [PMID: 25013017 DOI: 10.1161/strokeaha.114.005406] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Whether the mammalian target of rapamycin (mTOR) pathway is protective against brain injury from stroke or is detrimental is controversial, and whether it is involved in the protective effects of ischemic postconditioning (IPC) against stroke is unreported. Our study focuses on the protective role of mTOR against neuronal injury after stroke with and without IPC. METHODS We used both an in vitro oxygen-glucose deprivation model with a mixed neuronal culture and hypoxic postconditioning, as well as an in vivo stroke model with IPC. Rapamycin, a specific pharmacological inhibitor of mTOR, and mTOR short hairpin RNA lentiviral vectors were used to inhibit mTOR activity. A lentiviral vector expressing S6K1, a downstream molecule of mTOR, was used to confirm the protective effects of mTOR. Infarct sizes were measured and protein levels were examined by Western blot. RESULTS We report that stroke resulted in reduced levels of phosphorylated proteins in the mTOR pathway, including S6K1, S6, and 4EBP1, and that IPC increased these proteins. mTOR inhibition, both by the mTOR inhibitor rapamycin and by mTOR short hairpin RNA, worsened ischemic outcomes in vitro and in vivo and abolished the protective effects of hypoxic postconditioning and IPC on neuronal death in vitro and brain injury size in vivo. Overexpression of S6K1 mediated by lentiviral vectors significantly attenuated brain infarction. CONCLUSIONS mTOR plays a crucial protective role in brain damage after stroke and contributes to the protective effects of IPC.
Collapse
Affiliation(s)
- Rong Xie
- From the Departments of Neurosurgery (R.X., P.W., M.C., R.S., H.Z.) and Biological Sciences (M.C., R.S.), and Stanford Stroke Center (H.Z.), Stanford University, CA; Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China (R.X.); and Department of Neurosurgery, Xuanwu Hospital, Capital Medical School, Beijing, China (P.W., X.J.)
| | - Peng Wang
- From the Departments of Neurosurgery (R.X., P.W., M.C., R.S., H.Z.) and Biological Sciences (M.C., R.S.), and Stanford Stroke Center (H.Z.), Stanford University, CA; Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China (R.X.); and Department of Neurosurgery, Xuanwu Hospital, Capital Medical School, Beijing, China (P.W., X.J.)
| | - Michelle Cheng
- From the Departments of Neurosurgery (R.X., P.W., M.C., R.S., H.Z.) and Biological Sciences (M.C., R.S.), and Stanford Stroke Center (H.Z.), Stanford University, CA; Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China (R.X.); and Department of Neurosurgery, Xuanwu Hospital, Capital Medical School, Beijing, China (P.W., X.J.)
| | - Robert Sapolsky
- From the Departments of Neurosurgery (R.X., P.W., M.C., R.S., H.Z.) and Biological Sciences (M.C., R.S.), and Stanford Stroke Center (H.Z.), Stanford University, CA; Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China (R.X.); and Department of Neurosurgery, Xuanwu Hospital, Capital Medical School, Beijing, China (P.W., X.J.)
| | - Xunming Ji
- From the Departments of Neurosurgery (R.X., P.W., M.C., R.S., H.Z.) and Biological Sciences (M.C., R.S.), and Stanford Stroke Center (H.Z.), Stanford University, CA; Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China (R.X.); and Department of Neurosurgery, Xuanwu Hospital, Capital Medical School, Beijing, China (P.W., X.J.).
| | - Heng Zhao
- From the Departments of Neurosurgery (R.X., P.W., M.C., R.S., H.Z.) and Biological Sciences (M.C., R.S.), and Stanford Stroke Center (H.Z.), Stanford University, CA; Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China (R.X.); and Department of Neurosurgery, Xuanwu Hospital, Capital Medical School, Beijing, China (P.W., X.J.).
| |
Collapse
|
38
|
Ely BR, Lovering AT, Horowitz M, Minson CT. Heat acclimation and cross tolerance to hypoxia: Bridging the gap between cellular and systemic responses. Temperature (Austin) 2014; 1:107-14. [PMID: 27583292 PMCID: PMC4977168 DOI: 10.4161/temp.29800] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 07/01/2014] [Accepted: 07/01/2014] [Indexed: 11/29/2022] Open
Abstract
Recent research has suggested a potential for some of the physiological and cellular responses to heat acclimation to carry over to improved tolerance of the novel stresses of another environment. This cross-tolerance is evident in heat-acclimated animals that exhibit enhanced tolerance to either hypoxic or ischemic stress, and is primarily attributed to shared cellular stress response pathways. These pathways include Hypoxia-Inducible Factor-1 (HIF-1) and Heat Shock Proteins (HSP). Whether these shared cellular stress response pathways translate to systemic cross-tolerance (improved exercise tolerance, reduced risk of environment-associated illness) has not been clearly shown, particularly in humans. This review highlights the HIF-1 and HSP pathways and their relationship with systemic acclimation responses, and further examines the potential cellular and systemic adaptations that may result in cross-tolerance between hot and hypoxic environments.
Collapse
Affiliation(s)
- Brett R Ely
- University of Oregon; Department of Human Physiology; Eugene, OR USA
| | - Andrew T Lovering
- University of Oregon; Department of Human Physiology; Eugene, OR USA
| | - Michal Horowitz
- The Hebrew University of Jerusalem; Laboratory of Environmental Physiology; Faculty of Dental Medicine; Jerusalem, Israel
| | | |
Collapse
|
39
|
Kanngiesser M, Mair N, Lim HY, Zschiebsch K, Blees J, Häussler A, Brüne B, Ferreiròs N, Kress M, Tegeder I. Hypoxia-inducible factor 1 regulates heat and cold pain sensitivity and persistence. Antioxid Redox Signal 2014; 20:2555-71. [PMID: 24144405 DOI: 10.1089/ars.2013.5494] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
AIMS The present study assessed the functions of the transcription factor hypoxia-inducible factor (HIF) in sensory neurons in models of acute, inflammatory, ischemic, and neuropathic pain. The alpha subunit, HIF1α, was specifically deleted in neurons of the dorsal root ganglia by mating HIF1α(fl/fl) mice with SNScre mice. RESULTS SNS-HIF1α(-/-) mice were more sensitive to noxious heat and cold pain stimulation than were HIF1α(fl/fl) control mice. They also showed heightened first-phase nociceptive responses in the formalin and capsaicin tests with increased numbers of cFos-positive neurons in the dorsal horn, and intensified hyperalgesia in early phases after paw inflammation and hind limb ischemia/reperfusion. The behavioral cold and heat pain hypersensitivity was explained by increased calcium fluxes after transient receptor potential channel activation in primary sensory neurons of SNS-HIF1α(-/-) mice and lowered electrical activation thresholds of sensory fibers. SNS-HIF1α(-/-) mice however, developed less neuropathic pain after sciatic nerve injury, which was associated with an abrogation of HIF1-mediated gene up-regulation. INNOVATION The results suggest that HIF1α is protective in terms of acute heat and cold pain but in case of ongoing activation in injured neurons, it may promote the development of neuropathic pain. CONCLUSION The duality of HIF1 in pain regulation may have an impact on the side effects of drugs targeting HIF1, which are being developed, for example, as anticancer agents. Specifically, in patients with cancer neuropathy, however, temporary HIF1 inhibition might provide a welcome combination of growth and pain reduction.
Collapse
Affiliation(s)
- Maike Kanngiesser
- 1 Pharmazentrum Frankfurt/ZAFES, Institute of Clinical Pharmacology, Goethe-University Hospital Frankfurt , Frankfurt, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Kjell J, Codeluppi S, Josephson A, Abrams MB. Spatial and cellular characterization of mTORC1 activation after spinal cord injury reveals biphasic increase mainly attributed to microglia/macrophages. Brain Pathol 2014; 24:557-67. [PMID: 24576152 PMCID: PMC4347463 DOI: 10.1111/bpa.12135] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 02/17/2014] [Indexed: 01/07/2023] Open
Abstract
Mechanistic target of rapamycin complex 1 (mTORC1) is an intracellular kinase complex that regulates energy homeostasis and transcription. Modulation of mTORC1 has proven beneficial in experimental spinal cord injury, making this molecular target a candidate for therapeutic intervention in spinal cord injury. However, both inactivation and activation of mTORC1 have been reported beneficial for recovery. To obtain a more complete picture of mTORC1 activity, we aimed to characterize the spatiotemporal activation pattern of mTORC1 and identify activation in particular cell types after contusion spinal cord injury in rats. To be able to provide a spatial characterization of mTORC1 activation, we monitored activation of downstream target S6. We found robust mTORC1 activation both at the site of injury and in spinal segments rostral and caudal to the injury. There was constitutive mTORC1 activation in neurons that was biphasically reduced caudally after injury. We found biphasic mTORC1 activation in glial cells, primarily activated microglia/macrophages. Furthermore, we found mTORC1 activation in proliferating cells, suggesting this may be a function affected by mTORC1 modulation. Our results reveal potential windows of opportunity for therapeutic interference with mTORC1 signaling and immune cells as targets for inhibition of mTORC1 in spinal cord injury.
Collapse
Affiliation(s)
- Jacob Kjell
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | | | | | | |
Collapse
|
41
|
Huang BR, Chang PC, Yeh WL, Lee CH, Tsai CF, Lin C, Lin HY, Liu YS, Wu CYJ, Ko PY, Huang SS, Hsu HC, Lu DY. Anti-neuroinflammatory effects of the calcium channel blocker nicardipine on microglial cells: implications for neuroprotection. PLoS One 2014; 9:e91167. [PMID: 24621589 PMCID: PMC3951295 DOI: 10.1371/journal.pone.0091167] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2013] [Accepted: 02/11/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/OBJECTIVE Nicardipine is a calcium channel blocker that has been widely used to control blood pressure in severe hypertension following events such as ischemic stroke, traumatic brain injury, and intracerebral hemorrhage. However, accumulating evidence suggests that inflammatory processes in the central nervous system that are mediated by microglial activation play important roles in neurodegeneration, and the effect of nicardipine on microglial activation remains unresolved. METHODOLOGY/PRINCIPAL FINDINGS In the present study, using murine BV-2 microglia, we demonstrated that nicardipine significantly inhibits microglia-related neuroinflammatory responses. Treatment with nicardipine inhibited microglial cell migration. Nicardipine also significantly inhibited LPS plus IFN-γ-induced release of nitric oxide (NO), and the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Furthermore, nicardipine also inhibited microglial activation by peptidoglycan, the major component of the Gram-positive bacterium cell wall. Notably, nicardipine also showed significant anti-neuroinflammatory effects on microglial activation in mice in vivo. CONCLUSION/SIGNIFICANCE The present study is the first to report a novel inhibitory role of nicardipine on neuroinflammation and provides a new candidate agent for the development of therapies for inflammation-related neurodegenerative diseases.
Collapse
Affiliation(s)
- Bor-Ren Huang
- Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan
- Neurosurgery Department, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung, Taiwan
- School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Pei-Chun Chang
- Department of Bioinformatics, Asia University, Taichung, Taiwan
| | - Wei-Lan Yeh
- Department of Cell and Tissue Engineering, Changhua Christian Hospital, Changhua, Taiwan
| | - Chih-Hao Lee
- Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, United States of America
| | - Cheng-Fang Tsai
- Department of Biotechnology, Asia University, Taichung, Taiwan
| | - Chingju Lin
- Department of Physiology, School of Medicine, China Medical University, Taichung, Taiwan
| | - Hsiao-Yun Lin
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan
| | - Yu-Shu Liu
- Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan
| | - Caren Yu-Ju Wu
- Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan
| | - Pei-Ying Ko
- Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung, Taiwan
| | - Shiang-Suo Huang
- Department of Pharmacology and Institute of Medicine, College of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Horng-Chaung Hsu
- Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan
- Department of Orthopedic Surgery, China Medical University Hospital, Taichung, Taiwan
| | - Dah-Yuu Lu
- Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, Taiwan
| |
Collapse
|
42
|
Liao WL, Lin SC, Sunny Sun H, Tsai SJ. Hypoxia-induced tumor malignancy and drug resistance: Role of microRNAs. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.bgm.2014.01.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
43
|
Ye Z, Ye W, Deng Y, Wang J, Zhou G, Zhang X. HIF-1-modified BMSCs improve migration and reduce neuronal apoptosis after stroke in rats. ACTA ACUST UNITED AC 2013. [DOI: 10.1007/s11434-013-5936-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
44
|
Corcoran A, O'Connor JJ. Hypoxia-inducible factor signalling mechanisms in the central nervous system. Acta Physiol (Oxf) 2013; 208:298-310. [PMID: 23692777 DOI: 10.1111/apha.12117] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 04/01/2013] [Accepted: 05/16/2013] [Indexed: 12/22/2022]
Abstract
In the CNS, neurones are highly sensitive to the availability of oxygen. In conditions where oxygen availability is decreased, neuronal function can be altered, leading to injury and cell death. Hypoxia has been implicated in a number of central nervous system pathologies including stroke, head trauma and neurodegenerative diseases. Cellular responses to oxygen deprivation are complex and result in activation of short- and long-term mechanisms to conserve energy and protect cells. Failure of synaptic transmission can be observed within minutes following this hypoxia. The acute effects of hypoxia on synaptic transmission are primarily mediated by altering ion fluxes across membranes, pre-synaptic effects of adenosine and other actions at glutamatergic receptors. A more long-term feature of the response of neurones to hypoxia is the activation of transcription factors such as hypoxia-inducible factor. The activation of hypoxia-inducible factor is governed by a family of dioxygenases called hypoxia-inducible factor prolyl 4 hydroxylases (PHDs). Under hypoxic conditions, PHD activity is inhibited, thereby allowing hypoxia-inducible factor to accumulate and translocate to the nucleus, where it binds to the hypoxia-responsive element sequences of target gene promoters. Inhibition of PHD activity stabilizes hypoxia-inducible factor and other proteins thus acting as a neuroprotective agent. This review will focus on the response of neuronal cells to hypoxia-inducible factor and its targets, including the prolyl hydroxylases. We also present evidence for acute effects of PHD inhibition on synaptic transmission and plasticity in the hippocampus.
Collapse
Affiliation(s)
- A. Corcoran
- UCD School of Biomolecular and Biomedical Science; UCD Conway Institute of Biomolecular and Biomedical Research; UniversityCollege Dublin; Dublin; Ireland
| | - J. J. O'Connor
- UCD School of Biomolecular and Biomedical Science; UCD Conway Institute of Biomolecular and Biomedical Research; UniversityCollege Dublin; Dublin; Ireland
| |
Collapse
|
45
|
Effect of hypoxia/reoxygenation on the cytokine-induced production of nitric oxide and superoxide anion in cultured osteoarthritic synoviocytes. Osteoarthritis Cartilage 2013; 21:874-81. [PMID: 23523904 DOI: 10.1016/j.joca.2013.03.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 02/11/2013] [Accepted: 03/13/2013] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Hypoxia/reoxygenation (H/R) is an important feature in the osteoarthritis (OA) physiopathology. Nitric oxide (NO) is a significant proinflammatory mediator in the inflamed synovium. The purpose of this study was to investigate the effects of H/R on inducible NO synthase (iNOS) activity and expression in OA synoviocytes. In addition we studied the relationship between nitrosative stress and NADPH oxidase (NOX) in such conditions. METHODS Human cultured synoviocytes from OA patients were treated for 24 h with interleukin 1-β (IL-1β), tumour necrosis factor α (TNF-α) or neither; for the last 6 h, they were submitted to either normoxia or three periods of 1-h of hypoxia followed by 1-h of reoxygenation. ·NO metabolism (iNOS expression, nitrite and peroxynitrite measurements) was investigated. Furthermore, superoxide anion O2(·-) production, NOX subunit expression and nitrosylation were also assessed. RESULTS iNOS expression and nitrite (but not peroxynitrite) production were ~0.20 to ~0.12 nmol min(-1) mg proteins(-1) (P < 0.05), while NOXs' subunit expression and p47-phox phosphorylation were increased. NOXs and p47-phox were dramatically nitrosylated under H/R conditions (P < 0.05 vs normoxia). Using NOS inhibitors under H/R conditions, p47-phox nitrosylation was prevented and O2(·-) production was restored at normoxic levels (0.21 nmol min(-1) mg of proteins(-1)). CONCLUSIONS Our results provide evidence for an up-regulation of iNOS activity in OA synoviocytes under H/R conditions, associated to a down-regulation of NOX activity through nitrosylation. These findings highlight the importance of radical production to OA pathogenesis, and appraise the metabolic modifications of synovial cells under hypoxia.
Collapse
|
46
|
Brewster AL, Lugo JN, Patil VV, Lee WL, Qian Y, Vanegas F, Anderson AE. Rapamycin reverses status epilepticus-induced memory deficits and dendritic damage. PLoS One 2013; 8:e57808. [PMID: 23536771 PMCID: PMC3594232 DOI: 10.1371/journal.pone.0057808] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 01/26/2013] [Indexed: 12/27/2022] Open
Abstract
Cognitive impairments are prominent sequelae of prolonged continuous seizures (status epilepticus; SE) in humans and animal models. While often associated with dendritic injury, the underlying mechanisms remain elusive. The mammalian target of rapamycin complex 1 (mTORC1) pathway is hyperactivated following SE. This pathway modulates learning and memory and is associated with regulation of neuronal, dendritic, and glial properties. Thus, in the present study we tested the hypothesis that SE-induced mTORC1 hyperactivation is a candidate mechanism underlying cognitive deficits and dendritic pathology seen following SE. We examined the effects of rapamycin, an mTORC1 inhibitor, on the early hippocampal-dependent spatial learning and memory deficits associated with an episode of pilocarpine-induced SE. Rapamycin-treated SE rats performed significantly better than the vehicle-treated rats in two spatial memory tasks, the Morris water maze and the novel object recognition test. At the molecular level, we found that the SE-induced increase in mTORC1 signaling was localized in neurons and microglia. Rapamycin decreased the SE-induced mTOR activation and attenuated microgliosis which was mostly localized within the CA1 area. These findings paralleled a reversal of the SE-induced decreases in dendritic Map2 and ion channels levels as well as improved dendritic branching and spine density in area CA1 following rapamycin treatment. Taken together, these findings suggest that mTORC1 hyperactivity contributes to early hippocampal-dependent spatial learning and memory deficits and dendritic dysregulation associated with SE.
Collapse
Affiliation(s)
- Amy L. Brewster
- Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital and Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Joaquin N. Lugo
- Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital and Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Vinit V. Patil
- Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital and Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Wai L. Lee
- Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital and Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Yan Qian
- Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital and Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Fabiola Vanegas
- Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital and Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Anne E. Anderson
- Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital and Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Neurology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, United States of America
- * E-mail:
| |
Collapse
|
47
|
Wenker SD, Chamorro ME, Vittori DC, Nesse AB. Protective action of erythropoietin on neuronal damage induced by activated microglia. FEBS J 2013; 280:1630-42. [PMID: 23384249 DOI: 10.1111/febs.12172] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Revised: 12/22/2012] [Accepted: 01/22/2013] [Indexed: 11/30/2022]
Abstract
Inflammation is a physiological defense response, but may also represent a potential pathological process in neurological diseases. In this regard, microglia have a crucial role in either progression or amelioration of degenerative neuronal damage. Because of the role of hypoxia in pro-inflammatory mechanisms in the nervous system, and the potential anti-inflammatory protective effect of erythropoietin (Epo), we focused our investigation on the role of this factor on activation of microglia and neuroprotection. Activation of microglial cells (EOC-2) was achieved by chemical hypoxia induced by cobalt chloride (CoCl2 ) and characterized by increased levels of nitrite, tumor necrosis factor-α and reactive oxygen species production, as well as up-regulation of inducible nitric oxide synthase expression. Under these conditions, cell proliferation data and proliferating cell nuclear antigen (PCNA) staining demonstrated a mitogenic effect of chemical hypoxia. Even though pre-treatment with Epo did not prevent nitrite production, inducible nitric oxide synthase protein expression or tumor necrosis factor-α secretion, it prevented the oxidative stress induced by CoCl2 as well as cell proliferation. Neuronal cells (SH-SY5Y) cultured in the presence of conditioned medium from activated EOC-2 cells or macrophages (RAW 264.7) developed significant apoptosis, an effect that was abolished by Epo via Epo/Epo receptor activation. The results show that even though Epo did not exert a direct anti-inflammatory effect on microglia activation, it did increase the resistance of neurons to subsequent damage from pro-inflammatory agents. In addition to its anti-apoptotic ability, the Epo antioxidant effect may have an indirect influence on neuronal survival by modulation of the pro-inflammatory environment.
Collapse
Affiliation(s)
- Shirley D Wenker
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IQUIBICEN-CONICET (Instituto de Química Biológica, Facultad de Ciencias Exactas y Naturales-Consejo Nacional de Investigaciones Científicas y Técnicas), Buenos Aires, Argentina
| | | | | | | |
Collapse
|
48
|
Bao B, Azmi AS, Ali S, Ahmad A, Li Y, Banerjee S, Kong D, Sarkar FH. The biological kinship of hypoxia with CSC and EMT and their relationship with deregulated expression of miRNAs and tumor aggressiveness. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1826:272-96. [PMID: 22579961 PMCID: PMC3788359 DOI: 10.1016/j.bbcan.2012.04.008] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 04/25/2012] [Accepted: 04/28/2012] [Indexed: 12/13/2022]
Abstract
Hypoxia is one of the fundamental biological phenomena that are intricately associated with the development and aggressiveness of a variety of solid tumors. Hypoxia-inducible factors (HIF) function as a master transcription factor, which regulates hypoxia responsive genes and has been recognized to play critical roles in tumor invasion, metastasis, and chemo-radiation resistance, and contributes to increased cell proliferation, survival, angiogenesis and metastasis. Therefore, tumor hypoxia with deregulated expression of HIF and its biological consequence lead to poor prognosis of patients diagnosed with solid tumors, resulting in higher mortality, suggesting that understanding of the molecular relationship of hypoxia with other cellular features of tumor aggressiveness would be invaluable for developing newer targeted therapy for solid tumors. It has been well recognized that cancer stem cells (CSCs) and epithelial-to-mesenchymal transition (EMT) phenotypic cells are associated with therapeutic resistance and contribute to aggressive tumor growth, invasion, metastasis and believed to be the cause of tumor recurrence. Interestingly, hypoxia and HIF signaling pathway are known to play an important role in the regulation and sustenance of CSCs and EMT phenotype. However, the molecular relationship between HIF signaling pathway with the biology of CSCs and EMT remains unclear although NF-κB, PI3K/Akt/mTOR, Notch, Wnt/β-catenin, and Hedgehog signaling pathways have been recognized as important regulators of CSCs and EMT. In this article, we will discuss the state of our knowledge on the role of HIF-hypoxia signaling pathway and its kinship with CSCs and EMT within the tumor microenvironment. We will also discuss the potential role of hypoxia-induced microRNAs (miRNAs) in tumor development and aggressiveness, and finally discuss the potential effects of nutraceuticals on the biology of CSCs and EMT in the context of tumor hypoxia.
Collapse
Affiliation(s)
- Bin Bao
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Asfar S. Azmi
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Shadan Ali
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Aamir Ahmad
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Yiwei Li
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Sanjeev Banerjee
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Dejuan Kong
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Fazlul H. Sarkar
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
- Department of Oncology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| |
Collapse
|
49
|
Lin YM, Huang YL, Fong YC, Tsai CH, Chou MC, Tang CH. Hepatocyte growth factor increases vascular endothelial growth factor-A production in human synovial fibroblasts through c-Met receptor pathway. PLoS One 2012; 7:e50924. [PMID: 23209838 PMCID: PMC3508989 DOI: 10.1371/journal.pone.0050924] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Accepted: 10/26/2012] [Indexed: 11/19/2022] Open
Abstract
Background Angiogenesis is essential for the progression of osteoarthritis (OA). Hepatocyte growth factor (HGF) is an angiogenic mediator, and it shows elevated levels in regions of OA. However, the relationship between HGF and vascular endothelial growth factor (VEGF-A) in OA synovial fibroblasts (OASFs) is mostly unknown. Methodology/Principal Findings Here we found that stimulation of OASFs with HGF induced concentration- and time-dependent increases in VEGF-A expression. Pretreatment with PI3K inhibitor (Ly294002), Akt inhibitor, or mTORC1 inhibitor (rapamycin) blocked the HGF-induced VEGF-A production. Treatment of cells with HGF also increased PI3K, Akt, and mTORC1 phosphorylation. Furthermore, HGF increased the stability and activity of HIF-1 protein. Moreover, the use of pharmacological inhibitors or genetic inhibition revealed that c-Met, PI3K, Akt, and mTORC1 signaling pathways were potentially required for HGF-induced HIF-1α activation. Conclusions/Significance Taken together, our results provide evidence that HGF enhances VEGF-A expression in OASFs by an HIF-1α-dependent mechanism involving the activation of c-Met/PI3K/Akt and mTORC1 pathways.
Collapse
Affiliation(s)
- Yu-Min Lin
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan
- Department of Orthopedic Surgery, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Yuan-Li Huang
- Department of Biotechnology, College of Health Science, Asia University, Taichung, Taiwan
| | - Yi-Chin Fong
- Department of Orthopaedic Surgery, China Medical University Hospital, Taichung, Taiwan
- School of Chinese Medicine, China Medical University, Taichung, Taiwan
| | - Chun-Hao Tsai
- Department of Orthopaedic Surgery, China Medical University Hospital, Taichung, Taiwan
- Department of Medicine and Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan
| | - Ming-Chih Chou
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Chih-Hsin Tang
- Department of Pharmacology, School of Medicine, China Medical University, Taichung, Taiwan
- Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan
- * E-mail:
| |
Collapse
|
50
|
Dello Russo C, Lisi L, Feinstein DL, Navarra P. mTOR kinase, a key player in the regulation of glial functions: relevance for the therapy of multiple sclerosis. Glia 2012; 61:301-11. [PMID: 23044764 DOI: 10.1002/glia.22433] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 09/06/2012] [Accepted: 09/11/2012] [Indexed: 12/26/2022]
Abstract
The mammalian target of rapamycin (mTOR) is a serine/threonine protein kinase with a central role in the regulation of cell growth and proliferation, and several intracellular processes, such as mRNA transcription and translation, autophagy and cytoskeletal organization. The relevance of this pathway in the regulation of the immune system is well characterized. mTOR is essential for the proper activation and proliferation of effector T cells, restricts the development of regulatory T cells, and downregulates innate immune responses. Recently, a direct role of mTOR in the modulation of glial functions has also been recognized. Data from our group and others support the notion that mTOR is involved in microglial proinflammatory activation. The kinase regulates several intracellular processes in astrocytes, among which the rate of mRNA degradation of the inducible form of NO synthase. Therefore, the inhibition of mTOR kinase activity in glial cells results in anti-inflammatory actions, suggesting possible beneficial effects of mTOR inhibitors (like rapamycin) in the treatment of inflammatory-based pathologies of the central nervous system. In contrast, mTOR plays an important role in the regulation of oligodendrocyte development and myelination process as well as several neuronal functions, which may limit this therapeutic approach. Nevertheless, as reviewed here, there is robust evidence that rapamycin ameliorates the clinical course of both the relapsing-remitting and the chronic experimental autoimmune encephalomyelitis (EAE), and significantly reduces the hyperalgesia observed before clinical development of EAE. These findings may have important clinical implications for the therapy of multiple sclerosis.
Collapse
Affiliation(s)
- Cinzia Dello Russo
- Institute of Pharmacology, Catholic University Medical School, Rome, Italy.
| | | | | | | |
Collapse
|