1
|
The protective role of curcumin in human dental pulp stem cells stimulated by lipopolysaccharide via inhibiting NF-κB p65 phosphorylation to suppress NLRP3 inflammasome activation. Clin Oral Investig 2023:10.1007/s00784-023-04885-8. [PMID: 36735089 DOI: 10.1007/s00784-023-04885-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Accepted: 01/26/2023] [Indexed: 02/04/2023]
Abstract
OBJECTIVES This study aims to investigate the anti-inflammatory effect of curcumin and underlying mechanisms regarding the modulation of the nod-like receptor pyrin domain containing 3 (NLRP3) inflammasome in human dental pulp stem cells (hDPSCs). MATERIALS AND METHODS The impact of curcumin on the viability of hDPSCs was evaluated. The effect of curcumin on the expression of IL-1β and NLRP3 in hDPSCs stimulated by lipopolysaccharide (LPS) was assessed. Then, LPS-primed hDPSCs were pre-treated with curcumin before ATP triggering NLRP3 inflammasome activation, and NLRP3 inflammasome-related mediators were assessed. The mechanism of curcumin inactivation of LPS plus ATP-induced inflammasome associated with NF-κB pathway was explored. The NF-κB pathway related pro-inflammatory mediators at mRNA and protein levels were evaluated. The expression of NF-κB p65 and phosphorylation p65 was visualized after curcumin or NF-κB inhibitor administrating respectively in hDPSCs with an activated NLRP3 inflammasome. Statistical analysis was performed. RESULTS While curcumin at the concentration of 0.5-5 μM showed no obvious impact on the viability of hDPSCs, it significantly decreased IL-1β and NLRP3 mRNA expression in LPS-induced hDPSCs in a dose-dependent manner. Curcumin significantly inhibited the LPS plus ATP-primed NLRP3 inflammasome activation in hDPSCs (NLRP3, ASC, caspase-1, and IL-1β). Curcumin evidently attenuated the LPS plus ATP-induced expression of NF-κB pathway-related pro-inflammatory mediators (IL-6, IL-8, TNF-α, and COX-2). Furthermore, curcumin effectively reduced p65 phosphorylation, which acts as an NF-κB inhibitor in hDPSCs with an activated NLRP3 inflammasome. CONCLUSIONS Curcumin pre-treatment may exert an anti-inflammatory role via inactivation of the NLRP3 inflammasome by inhibiting NF-κB p65 phosphorylation in cultured hDPSCs. CLINICAL RELEVANCE Curcumin may have therapeutic potential in pulp inflammation.
Collapse
|
2
|
Wang Y, Hu Z, Liu H, Gu Y, Ye M, Lu Q, Lu X, Huang C. Adolescent microglia stimulation produces long-lasting protection against chronic stress-induced behavioral abnormalities in adult male mice. Brain Behav Immun 2022; 105:44-66. [PMID: 35781008 DOI: 10.1016/j.bbi.2022.06.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 06/05/2022] [Accepted: 06/28/2022] [Indexed: 11/18/2022] Open
Abstract
Our previous studies had reported that microglia activation one day before stress exposure prevented the behavioral abnormalities induced by chronic stress in adult mice, and a 10-day interval between microglia stimulation and stress exposure can abolish the prophylactic effect of LPS preinjection on the behavioral abnormalities induced by chronic stress, which, however, could be rescued by repeated LPS injection. This suggests that increased stimulation of microglia results in animals developing a strong ability to prevent deleterious stress stimuli. Because microglia in the adolescent brain exhibit flexible immunological plasticity, we hypothesize that a single low-dose LPS injection during adolescence may provide long-lasting protection against behavioral abnormalities induced by chronic stress in adult mice. As expected, our results showed that a single injection of LPS (100 μg/kg) at post-natal day 28 (PND 28) prevented the development of abnormal behaviors and shifted neuroinflammatory responses toward an anti-inflammatory phenotype in adult mice treated with CSDS at their different stages of the age (PND 56, 140, and 252). Moreover, pretreatment with minocycline or PLX3397 to inhibit microglial activation abolished the prophylactic effect of LPS preinjection after PND 28 on behavioral abnormalities and neuroinflammatory responses induced by CSDS in adult mice at their different stages of the age, PND 56, 140, and 252. These results indicate that stimulation of microglia in adolescence may confer long-lasting protection against neuroinflammatory responses and behavioral abnormalities induced by chronic stress in adult mice. This may offer the potential for the development of a "vaccine-like strategy" to prevent mental disorders.
Collapse
Affiliation(s)
- Yue Wang
- Department of Pharmacology, School of Pharmacy, Nantong University, #19 Qixiu Road, Nantong 226001, Jiangsu, China
| | - Zhichao Hu
- Department of Pharmacology, School of Pharmacy, Nantong University, #19 Qixiu Road, Nantong 226001, Jiangsu, China
| | - Huijun Liu
- Department of Pharmacy, Yancheng First Hospital, the Fourth Affiliated Hospital of Nantong University, #66 Renmin South Road, Yancheng 224006, Jiangsu, China
| | - Yue Gu
- Department of Pharmacology, School of Pharmacy, Nantong University, #19 Qixiu Road, Nantong 226001, Jiangsu, China
| | - Minxiu Ye
- Department of Pharmacology, School of Pharmacy, Nantong University, #19 Qixiu Road, Nantong 226001, Jiangsu, China
| | - Qun Lu
- Department of Pharmacy, Nantong Third Hospital Affiliated to Nantong University, #60 Middle Qingnian Road, Nantong 226006, Jiangsu, China
| | - Xu Lu
- Department of Pharmacology, School of Pharmacy, Nantong University, #19 Qixiu Road, Nantong 226001, Jiangsu, China
| | - Chao Huang
- Department of Pharmacology, School of Pharmacy, Nantong University, #19 Qixiu Road, Nantong 226001, Jiangsu, China.
| |
Collapse
|
3
|
Alghamdi SS, Suliman RS, Aljammaz NA, Kahtani KM, Aljatli DA, Albadrani GM. Natural Products as Novel Neuroprotective Agents; Computational Predictions of the Molecular Targets, ADME Properties, and Safety Profile. PLANTS (BASEL, SWITZERLAND) 2022; 11:549. [PMID: 35214883 PMCID: PMC8878483 DOI: 10.3390/plants11040549] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 01/20/2022] [Accepted: 02/15/2022] [Indexed: 06/14/2023]
Abstract
Neurodegenerative diseases (NDs) are one of the most challenging public health issues. Despite tremendous advances in our understanding of NDs, little progress has been made in establishing effective treatments. Natural products may have enormous potential in preventing and treating NDs by targeting microglia; yet, there have been several clinical concerns about their usage, primarily due to a lack of scientific evidence for their efficacy, molecular targets, physicochemical properties, and safety. To solve this problem, the secondary bioactive metabolites derived from neuroprotective medicinal plants were identified and selected for computational predictions for anti-inflammatory activity, possible molecular targets, physicochemical properties, and safety evaluation using PASS online, Molinspiration, SwissADME, and ProTox-II, respectively. Most of the phytochemicals were active as anti-inflammatory agents as predicted using the PASS online webserver. Moreover, the molecular target predictions for some phytochemicals were similar to the reported experimental targets. Moreover, the phytochemicals that did not violate important physicochemical properties, including blood-brain barrier penetration, GI absorption, molecular weight, and lipophilicity, were selected for further safety evaluation. After screening 54 neuroprotective phytochemicals, our findings suggest that Aromatic-turmerone, Apocynin, and Matrine are the most promising compounds that could be considered when designing novel neuroprotective agents to treat neurodegenerative diseases via modulating microglial polarization.
Collapse
Affiliation(s)
- Sahar Saleh Alghamdi
- College of Pharmacy, King Saud bin Abdulaziz University for Health Sciences, Riyadh 11481, Saudi Arabia; (R.S.S.); (N.A.A.); (K.M.K.); (D.A.A.)
- King Abdullah International Medical Research Centre (KAIMRC), Ministry of National Guard Health Affairs, Riyadh 11481, Saudi Arabia
| | - Rasha Saad Suliman
- College of Pharmacy, King Saud bin Abdulaziz University for Health Sciences, Riyadh 11481, Saudi Arabia; (R.S.S.); (N.A.A.); (K.M.K.); (D.A.A.)
- King Abdullah International Medical Research Centre (KAIMRC), Ministry of National Guard Health Affairs, Riyadh 11481, Saudi Arabia
| | - Norah Abdulaziz Aljammaz
- College of Pharmacy, King Saud bin Abdulaziz University for Health Sciences, Riyadh 11481, Saudi Arabia; (R.S.S.); (N.A.A.); (K.M.K.); (D.A.A.)
| | - Khawla Mohammed Kahtani
- College of Pharmacy, King Saud bin Abdulaziz University for Health Sciences, Riyadh 11481, Saudi Arabia; (R.S.S.); (N.A.A.); (K.M.K.); (D.A.A.)
| | - Dimah Abdulqader Aljatli
- College of Pharmacy, King Saud bin Abdulaziz University for Health Sciences, Riyadh 11481, Saudi Arabia; (R.S.S.); (N.A.A.); (K.M.K.); (D.A.A.)
| | - Ghadeer M. Albadrani
- Department of Biology, College of Science, Princess Nourah bint Abdulrahman University, Riyadh 11474, Saudi Arabia;
| |
Collapse
|
4
|
Li F, Lu X, Ma Y, Gu Y, Ye T, Huang C. Monophosphoryl Lipid A Tolerance Against Chronic Stress-Induced Depression-Like Behaviors in Mice. Int J Neuropsychopharmacol 2022; 25:399-411. [PMID: 35015863 PMCID: PMC9154281 DOI: 10.1093/ijnp/pyab097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 11/29/2021] [Accepted: 01/06/2022] [Indexed: 11/27/2022] Open
Abstract
BACKGROUNDS Our recent studies reported that a single injection with lipopolysaccharide (LPS) before stress exposure prevents depression-like behaviors in stressed mice. Monophosphoryl lipid A (MPL) is a derivative of LPS that lacks the undesirable properties of LPS. We hypothesize that MPL can exert a prophylactic effect on depression. METHODS The experimental mice were pre-injected with MPL before stress exposure. Depression in mice was induced through chronic social defeat stress (CSDS). Behavioral tests were conducted to identify depression-like behaviors. Real-time polymerase chain reaction and biochemical assays were performed to examine the gene and protein expression levels of pro-inflammatory cytokines. RESULTS A single MPL injection 1 day before stress exposure at the dosages of 400, 800, and 1600 μg/kg but not 200 μg/kg prevented CSDS-induced depression-like behaviors in mice. This effect of MPL, however, vanished with the extension of the interval time between drug injection and stress exposure from 1 day or 5 days to 10 days, which was rescued by a second MPL injection 10 days after the first MPL injection or by a 4× MPL injection 10 days before stress exposure. A single MPL injection (800 μg/kg) before stress exposure prevented CSDS-induced increases in the gene expression levels of pro-inflammatory cytokines in the hippocampus and prefrontal cortex. Pre-inhibiting the innate immune stimulation by minocycline pretreatment (40 mg/kg) abrogated the preventive effect of MPL on CSDS-induced depression-like behaviors and neuroinflammatory responses in animal brains. CONCLUSIONS MPL, through innate immune stimulation, prevents stress-induced depression-like behaviors in mice by preventing neuroinflammatory responses.
Collapse
Affiliation(s)
| | | | | | | | - Ting Ye
- Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, Jiangsu, China
| | - Chao Huang
- Correspondence: Chao Huang, Department of Pharmacology, School of Pharmacy, Nantong University, #19 Qixiu Road, Nantong 226001, Jiangsu Province, China ()
| |
Collapse
|
5
|
Li F, Xiang H, Gu Y, Ye T, Lu X, Huang C. Innate immune stimulation by monophosphoryl lipid A prevents chronic social defeat stress-induced anxiety-like behaviors in mice. J Neuroinflammation 2022; 19:12. [PMID: 34996472 PMCID: PMC8742352 DOI: 10.1186/s12974-021-02377-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 12/29/2021] [Indexed: 02/06/2023] Open
Abstract
Background Innate immune pre-stimulation can prevent the development of depression-like behaviors in chronically stressed mice; however, whether the same stimulation prevents the development of anxiety-like behaviors in animals remains unclear. We addressed this issue using monophosphoryl lipid A (MPL), a derivative of lipopolysaccharide (LPS) that lacks undesirable properties of LPS but still keeps immune-enhancing activities. Methods The experimental mice were pre-injected intraperitoneally with MPL before stress exposure. Depression was induced through chronic social defeat stress (CSDS). Behavioral tests were conducted to identify anxiety-like behaviors. Real-time polymerase chain reaction (PCR) and biochemical assays were employed to examine the gene and protein expression levels of pro-inflammatory markers. Results A single MPL injection at the dose of 400 and 800 μg/kg 1 day before stress exposure prevented CSDS-induced anxiety-like behaviors, and a single MPL injection (400 μg/kg) five but not 10 days before stress exposure produced similar effect. The preventive effect of MPL on anxiety-like behaviors was also observed in CSDS mice who received a second MPL injection 10 days after the first MPL injection or a 4 × MPL injection 10 days before stress exposure. MPL pre-injection also prevented the production of pro-inflammatory cytokines in the hippocampus and medial prefrontal cortex in CSDS mice, and inhibiting the central immune response by minocycline pretreatment abrogated the preventive effect of MPL on CSDS-induced anxiety-like behaviors and pro-inflammatory cytokine productions in the brain. Conclusions Pre-stimulation of the innate immune system by MPL can prevent chronic stress-induced anxiety-like behaviors and neuroinflammatory responses in the brain in mice.
Collapse
Affiliation(s)
- Fu Li
- Department of Pharmacy, Changzhou Geriatric Hospital Affiliated to Soochow University, Changzhou No.7 People's Hospital, 288# Yanling East Road, Changzhou, 213000, Jiangsu, China
| | - Haitao Xiang
- Department of Neurosurgery, Suzhou Kowloon Hospital, Shanghai Jiaotong University School of Medicine, #118 Wansheng Street, Suzhou, 215028, Jiangsu, China
| | - Yue Gu
- Department of Pharmacology, School of Pharmacy, Nantong University, #19 Qixiu Road, Jiangsu, 226001, Nantong, China
| | - Ting Ye
- Department of Pharmacology, School of Pharmacy, Nantong University, #19 Qixiu Road, Jiangsu, 226001, Nantong, China
| | - Xu Lu
- Department of Pharmacology, School of Pharmacy, Nantong University, #19 Qixiu Road, Jiangsu, 226001, Nantong, China.
| | - Chao Huang
- Department of Pharmacology, School of Pharmacy, Nantong University, #19 Qixiu Road, Jiangsu, 226001, Nantong, China.
| |
Collapse
|
6
|
Zhou M, Zhang T, Zhang B, Zhang X, Gao S, Zhang T, Li S, Cai X, Lin Y. A DNA Nanostructure-Based Neuroprotectant against Neuronal Apoptosis via Inhibiting Toll-like Receptor 2 Signaling Pathway in Acute Ischemic Stroke. ACS NANO 2021; 16:1456-1470. [PMID: 34967217 DOI: 10.1021/acsnano.1c09626] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Ischemic stroke is a main cause of cognitive neurological deficits and disability worldwide due to a plethora of neuronal apoptosis. Unfortunately, numerous neuroprotectants for neurons have failed because of biological toxicity, severe side effects, and poor efficacy. Tetrahedral framework nucleic acids (tFNAs) possess excellent biocompatibility and various biological functions. Here, we tested the efficacy of a tFNA for providing neuroprotection against neuronal apoptosis in ischemic stroke. The tFNA prevented apoptosis of neurons (SHSY-5Y cells) caused by oxygen-glucose deprivation/reoxygenation through interfering with ischemia cascades (excitotoxicity and oxidative stress) in vitro. It effectively ameliorated the microenvironment of the ischemic hemisphere by upregulating expression of erythropoietin and inhibiting inflammation, which reversed neuronal loss, alleviated cell apoptosis, significantly shrank the infarction volume from 33.9% to 2.7%, and attenuated neurological deficits in transient middle cerebral artery occlusion (tMCAo) rat models in vivo. In addition, blocking the TLR2-MyD88-NF-κB signaling pathway is a potential mechanism of the neuroprotection by tFNA in ischemic stroke. These findings indicate that tFNA is a safe pleiotropic nanoneuroprotectant and a promising therapeutic strategy for ischemic stroke.
Collapse
Affiliation(s)
- Mi Zhou
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, People’s Republic of China
| | - Tianxu Zhang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, People’s Republic of China
| | - Bowen Zhang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, People’s Republic of China
| | - Xiaolin Zhang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, People’s Republic of China
| | - Shaojingya Gao
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, People’s Republic of China
| | - Tao Zhang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, People’s Republic of China
| | - Songhang Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, People’s Republic of China
| | - Xiaoxiao Cai
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, People’s Republic of China
| | - Yunfeng Lin
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, People’s Republic of China
- College of Biomedical Engineering, Sichuan University, Chengdu 610041, People’s Republic of China
| |
Collapse
|
7
|
Petrisko TJ, Konat GW. Peripheral viral challenge increases c-fos level in cerebral neurons. Metab Brain Dis 2021; 36:1995-2002. [PMID: 34406561 DOI: 10.1007/s11011-021-00819-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 08/05/2021] [Indexed: 12/01/2022]
Abstract
Peripheral viral infection can substantially alter brain function. We have previously shown that intraperitoneal (i.p.) injection of a viral mimetic, polyinosinic-polycytidylic acid (PIC), engenders hyperexcitability of cerebral neurons. Because neuronal activity is invariably associated with their expression of the Cfos gene, the present study was undertaken to determine whether PIC challenge also increases neuronal c-fos protein level. Female C57BL/6 mice were i.p. injected with PIC, and neuronal c-fos was analyzed in the motor cortex by immunohistochemistry. PIC challenge instigated a robust increase in the number of c-fos-positive neurons. This increase reached approximately tenfold over control at 24 h. Also, the c-fos staining intensity of individual neurons increased. AMG-487, a specific inhibitor of the chemokine receptor CXCR3, profoundly attenuated the accumulation of neuronal c-fos, indicating the activation of CXCL10/CXCR3 axis as the trigger of the process. Together, these results show that the accumulation of c-fos is a viable readout to assess the response of cerebral neurons to peripheral PIC challenge, and to elucidate the underlying molecular mechanisms.
Collapse
Affiliation(s)
- Tiffany J Petrisko
- Department of Biochemistry, Department of Neuroscience and Rockefeller Neuroscience Institute, West Virginia University School of Medicine, Morgantown, WV, 26506, USA
| | - Gregory W Konat
- Department of Biochemistry, Department of Neuroscience and Rockefeller Neuroscience Institute, West Virginia University School of Medicine, Morgantown, WV, 26506, USA.
- Department of Biochemistry, West Virginia University School of Medicine, 4052 HSCN, P.O. Box 9128, Morgantown, WV, 26506-9128, USA.
| |
Collapse
|
8
|
Ashayeri Ahmadabad R, Mirzaasgari Z, Gorji A, Khaleghi Ghadiri M. Toll-Like Receptor Signaling Pathways: Novel Therapeutic Targets for Cerebrovascular Disorders. Int J Mol Sci 2021; 22:ijms22116153. [PMID: 34200356 PMCID: PMC8201279 DOI: 10.3390/ijms22116153] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 06/02/2021] [Accepted: 06/04/2021] [Indexed: 12/11/2022] Open
Abstract
Toll-like receptors (TLRs), a class of pattern recognition proteins, play an integral role in the modulation of systemic inflammatory responses. Cerebrovascular diseases (CVDs) are a group of pathological conditions that temporarily or permanently affect the brain tissue mostly via the decrease of oxygen and glucose supply. TLRs have a critical role in the activation of inflammatory cascades following hypoxic-ischemic events and subsequently contribute to neuroprotective or detrimental effects of CVD-induced neuroinflammation. The TLR signaling pathway and downstream cascades trigger immune responses via the production and release of various inflammatory mediators. The present review describes the modulatory role of the TLR signaling pathway in the inflammatory responses developed following various CVDs and discusses the potential benefits of the modulation of different TLRs in the improvement of functional outcomes after brain ischemia.
Collapse
Affiliation(s)
- Rezan Ashayeri Ahmadabad
- Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran 1996835911, Iran; (R.A.A.); (Z.M.)
| | - Zahra Mirzaasgari
- Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran 1996835911, Iran; (R.A.A.); (Z.M.)
- Department of Neurology, Iran University of Medical Sciences, Tehran 1593747811, Iran
| | - Ali Gorji
- Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran 1996835911, Iran; (R.A.A.); (Z.M.)
- Epilepsy Research Center, Westfälische Wilhelms-Universität, 48149 Münster, Germany
- Neuroscience Research Center, Mashhad University of Medical Sciences, Mashhad 9177948564, Iran
- Department of Neurosurgery, Westfälische Wilhelms-Universität, 48149 Münster, Germany;
- Department of Neurology, Westfälische Wilhelms-Universität Münster, 48149 Münster, Germany
- Correspondence: ; Tel.: +49-251-8355564; Fax: +49-251-8347479
| | | |
Collapse
|
9
|
TLR4 Signaling Selectively and Directly Promotes CGRP Release from Vagal Afferents in the Mouse. eNeuro 2021; 8:ENEURO.0254-20.2020. [PMID: 33318075 PMCID: PMC7877464 DOI: 10.1523/eneuro.0254-20.2020] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 12/03/2020] [Accepted: 12/03/2020] [Indexed: 12/14/2022] Open
Abstract
There has been a long-standing debate regarding the role of peripheral afferents in mediating rapid-onset anorexia among other responses elicited by peripheral inflammatory insults. Thus, the current study assessed the sufficiency of peripheral afferents expressing toll-like receptor 4 (TLR4) to the initiation of the anorexia caused by peripheral bacterial lipopolysaccharide (LPS). We generated a Tlr4 null (Tlr4LoxTB) mouse in which Tlr4 expression is globally disrupted by a loxP-flanked transcription blocking (TB) cassette. This novel mouse model allowed us to restore the endogenous TLR4 expression in specific cell types. Using Zp3-Cre and Nav1.8-Cre mice, we produced mice that express TLR4 in all cells (Tlr4LoxTB X Zp3-Cre) and in peripheral afferents (Tlr4LoxTB X Nav1.8-Cre), respectively. We validated the Tlr4LoxTB mice, which were phenotypically identical to previously reported global TLR4 knock-out mice. Contrary to our expectations, the administration of LPS did not cause rapid-onset anorexia in mice with Nav1.8-restricted TLR4. The later result prompted us to identify Tlr4-expressing vagal afferents using in situ hybridization (ISH). In vivo, we found that Tlr4 mRNA was primarily enriched in vagal Nav1.8 afferents located in the jugular ganglion that co-expressed calcitonin gene-related peptide (CGRP). In vitro, the application of LPS to cultured Nav1.8-restricted TLR4 afferents was sufficient to stimulate the release of CGRP. In summary, we demonstrated using a new mouse model that vagally-expressed TLR4 is selectively involved in stimulating the release of CGRP but not in causing anorexia.
Collapse
|
10
|
Toll-like receptors in Alzheimer's disease. J Neuroimmunol 2020; 348:577362. [DOI: 10.1016/j.jneuroim.2020.577362] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/04/2020] [Accepted: 08/15/2020] [Indexed: 02/07/2023]
|
11
|
Serial Systemic Injections of Endotoxin (LPS) Elicit Neuroprotective Spinal Cord Microglia through IL-1-Dependent Cross Talk with Endothelial Cells. J Neurosci 2020; 40:9103-9120. [PMID: 33051350 DOI: 10.1523/jneurosci.0131-20.2020] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 09/13/2020] [Accepted: 09/17/2020] [Indexed: 12/12/2022] Open
Abstract
Microglia are dynamic immunosurveillance cells in the CNS. Whether microglia are protective or pathologic is context dependent; the outcome varies as a function of time relative to the stimulus, activation state of neighboring cells in the microenvironment or within progression of a particular disease. Although brain microglia can be "primed" using bacterial lipopolysaccharide (LPS)/endotoxin, it is unknown whether LPS delivered systemically can also induce neuroprotective microglia in the spinal cord. Here, we show that serial systemic injections of LPS (1 mg/kg, i.p., daily) for 4 consecutive days (LPSx4) consistently elicit a reactive spinal cord microglia response marked by dramatic morphologic changes, increased production of IL-1, and enhanced proliferation without triggering leukocyte recruitment or overt neuropathology. Following LPSx4, reactive microglia frequently contact spinal cord endothelial cells. Targeted ablation or selective expression of IL-1 and IL-1 receptor (IL-1R) in either microglia or endothelia reveal that IL-1-dependent signaling between these cells mediates microglia activation. Using a mouse model of ischemic spinal cord injury in male and female mice, we show that preoperative LPSx4 provides complete protection from ischemia-induced neuron loss and hindlimb paralysis. Neuroprotection is partly reversed by either pharmacological elimination of microglia or selective removal of IL-1R in microglia or endothelia. These data indicate that spinal cord microglia are amenable to therapeutic reprogramming via systemic manipulation and that this potential can be harnessed to protect the spinal cord from injury.SIGNIFICANCE STATEMENT Data in this report indicate that a neuroprotective spinal cord microglia response can be triggered by daily systemic injections of LPS over a period of 4 d (LPSx4). The LPSx4 regimen induces morphologic transformation and enhances proliferation of spinal cord microglia without causing neuropathology. Using advanced transgenic mouse technology, we show that IL-1-dependent microglia-endothelia cross talk is necessary for eliciting this spinal cord microglia phenotype and also for conferring optimal protection to spinal motor neurons from ischemic spinal cord injury (ISCI). Collectively, these novel data show that it is possible to consistently elicit spinal cord microglia via systemic delivery of inflammogens to achieve a therapeutically effective neuroprotective response against ISCI.
Collapse
|
12
|
Ohgomori T, Jinno S. Modulation of neuropathology and cognitive deficits by lipopolysaccharide preconditioning in a mouse pilocarpine model of status epilepticus. Neuropharmacology 2020; 176:108227. [PMID: 32634527 DOI: 10.1016/j.neuropharm.2020.108227] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/15/2020] [Accepted: 06/29/2020] [Indexed: 02/06/2023]
Abstract
Recent studies indicate that microglia may play a critical role in epileptogenesis during the early post-status epilepticus (SE) period. In this study, we aimed to elucidate the effects of preconditioning of microglia with lipopolysaccharide (LPS) on neuropathology and cognitive deficits in a mouse pilocarpine model of SE. Mice were treated with an intraperitoneal injection of LPS 24 h before SE induction. The open field test at 13 days after SE showed that LPS preconditioning suppressed SE-induced hyperactivity. The Y-maze test at 14 days after SE showed that LPS preconditioning ameliorated SE-induced working memory impairment. The extent of neuronal damage was decreased by LPS preconditioning in the hippocampus of mice euthanized at 15 days after SE. Gene profile analysis of hippocampal microglia at 15 days after SE showed that the expression level of interleukin-1β was increased by SE induction but decreased by LPS preconditioning. By contrast, SE induction increased the expression levels of phagocytosis-related genes, and LPS preconditioning further enhanced their expression. Interestingly, LPS preconditioning increased the numerical density of hippocampal microglia expressing the 5D4 keratan sulfate epitope, a population of cells known to be involved in phagocytosis. The voxel density of glutamatergic synapses was increased by SE induction but decreased by LPS preconditioning, while GABAergic synapses were not affected by these procedures. Our findings indicate that LPS preconditioning may in part alleviate SE-related abnormal synaptogenesis and cognitive deficits, and also suggest that modulation of microglial activation during the early post-SE period may be a novel strategy for epilepsy treatment.
Collapse
Affiliation(s)
- Tomohiro Ohgomori
- Department of Anatomy and Neuroscience, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan; Department of Rehabilitation, Faculty of Rehabilitation, Osaka Kawasaki Rehabilitation University, Kaizuka, 597-0104, Japan
| | - Shozo Jinno
- Department of Anatomy and Neuroscience, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan.
| |
Collapse
|
13
|
Ashayeri Ahmadabad R, Khaleghi Ghadiri M, Gorji A. The role of Toll-like receptor signaling pathways in cerebrovascular disorders: the impact of spreading depolarization. J Neuroinflammation 2020; 17:108. [PMID: 32264928 PMCID: PMC7140571 DOI: 10.1186/s12974-020-01785-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 03/24/2020] [Indexed: 02/08/2023] Open
Abstract
Cerebral vascular diseases (CVDs) are a group of disorders that affect the blood supply to the brain and lead to the reduction of oxygen and glucose supply to the neurons and the supporting cells. Spreading depolarization (SD), a propagating wave of neuroglial depolarization, occurs in different CVDs. A growing amount of evidence suggests that the inflammatory responses following hypoxic-ischemic insults and after SD plays a double-edged role in brain tissue injury and clinical outcome; a beneficial effect in the acute phase and a destructive role in the late phase. Toll-like receptors (TLRs) play a crucial role in the activation of inflammatory cascades and subsequent neuroprotective or harmful effects after CVDs and SD. Here, we review current data regarding the pathophysiological role of TLR signaling pathways in different CVDs and discuss the role of SD in the potentiation of the inflammatory cascade in CVDs through the modulation of TLRs.
Collapse
Affiliation(s)
- Rezan Ashayeri Ahmadabad
- Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran, Iran
- Department of Neurosurgery, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | | | - Ali Gorji
- Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran, Iran.
- Department of Neurosurgery, Westfälische Wilhelms-Universität Münster, Münster, Germany.
- Epilepsy Research Center, Westfälische Wilhelms-Universität Münster, Münster, Germany.
- Department of Neurology, Westfälische Wilhelms-Universität Münster, Münster, Germany.
- Neuroscience research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
| |
Collapse
|
14
|
Eslami M, Alizadeh L, Morteza-Zadeh P, Sayyah M. The effect of Lipopolysaccharide (LPS) pretreatment on hippocampal apoptosis in traumatic rats. Neurol Res 2020; 42:91-98. [PMID: 31914902 DOI: 10.1080/01616412.2019.1709139] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Objectives: Traumatic brain injury (TBI) is a serious medical problem that affects the quality of life. Apoptosis is a form of programmed cell death that happens after trauma. Effector caspases are responsible for initiating apoptosis.Methods: In the present study, we examined the effect of LPS preconditioning (0.1 and 0.5 mg/kg, ip; 5 days prior controlled cortical injury) on apoptosis, 4 and 12 hours after trauma. We investigated possible mechanisms on the expression of caspase3 and caspase7 in hippocampal CA1 and CA3 areas by using immunohistochemistry and Western blotting techniques and also TUNEL-positive cells.Results: Higher expression of caspase3 and caspase7 were accompanied by a higher number of dead neurons in traumatic rats 4 and 12 hours after trauma(P < 0.05). LPS preconditioning decreased caspase3 and caspase7over-expression and the number of dead neurons in the hippocampus(P < 0.05).Discussion: Our data indicate that LPS preconditioning inhibits neural damage and apoptosis induced by trauma in the hippocampus.
Collapse
Affiliation(s)
- Mansoureh Eslami
- Department of Basic Sciences, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Leila Alizadeh
- Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran, Iran
| | | | - Mohammad Sayyah
- Department of Physiology and Pharmacology, Pasteur Institute of Iran, Tehran, Iran
| |
Collapse
|
15
|
Preconditioning with toll-like receptor agonists attenuates seizure activity and neuronal hyperexcitability in the pilocarpine rat model of epilepsy. Neuroscience 2019; 408:388-399. [DOI: 10.1016/j.neuroscience.2019.04.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 04/06/2019] [Accepted: 04/08/2019] [Indexed: 01/24/2023]
|
16
|
Neuroprotective and anti-inflammatory effects of isoliquiritigenin in kainic acid-induced epileptic rats via the TLR4/MYD88 signaling pathway. Inflammopharmacology 2019; 27:1143-1153. [DOI: 10.1007/s10787-019-00592-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 03/29/2019] [Indexed: 10/26/2022]
|
17
|
Xu M, Liu PP, Li H. Innate Immune Signaling and Its Role in Metabolic and Cardiovascular Diseases. Physiol Rev 2019; 99:893-948. [PMID: 30565509 DOI: 10.1152/physrev.00065.2017] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The innate immune system is an evolutionarily conserved system that senses and defends against infection and irritation. Innate immune signaling is a complex cascade that quickly recognizes infectious threats through multiple germline-encoded cell surface or cytoplasmic receptors and transmits signals for the deployment of proper countermeasures through adaptors, kinases, and transcription factors, resulting in the production of cytokines. As the first response of the innate immune system to pathogenic signals, inflammatory responses must be rapid and specific to establish a physical barrier against the spread of infection and must subsequently be terminated once the pathogens have been cleared. Long-lasting and low-grade chronic inflammation is a distinguishing feature of type 2 diabetes and cardiovascular diseases, which are currently major public health problems. Cardiometabolic stress-induced inflammatory responses activate innate immune signaling, which directly contributes to the development of cardiometabolic diseases. Additionally, although the innate immune elements are highly conserved in higher-order jawed vertebrates, lower-grade jawless vertebrates lack several transcription factors and inflammatory cytokine genes downstream of the Toll-like receptors (TLRs) and retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs) pathways, suggesting that innate immune signaling components may additionally function in an immune-independent way. Notably, recent studies from our group and others have revealed that innate immune signaling can function as a vital regulator of cardiometabolic homeostasis independent of its immune function. Therefore, further investigation of innate immune signaling in cardiometabolic systems may facilitate the discovery of new strategies to manage the initiation and progression of cardiometabolic disorders, leading to better treatments for these diseases. In this review, we summarize the current progress in innate immune signaling studies and the regulatory function of innate immunity in cardiometabolic diseases. Notably, we highlight the immune-independent effects of innate immune signaling components on the development of cardiometabolic disorders.
Collapse
Affiliation(s)
- Meng Xu
- Department of Cardiology, Renmin Hospital of Wuhan University , Wuhan , China ; Medical Research Center, Zhongnan Hospital of Wuhan University , Wuhan , China ; Animal Experiment Center, Wuhan University , Wuhan , China ; Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa, Ontario , Canada
| | - Peter P Liu
- Department of Cardiology, Renmin Hospital of Wuhan University , Wuhan , China ; Medical Research Center, Zhongnan Hospital of Wuhan University , Wuhan , China ; Animal Experiment Center, Wuhan University , Wuhan , China ; Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa, Ontario , Canada
| | - Hongliang Li
- Department of Cardiology, Renmin Hospital of Wuhan University , Wuhan , China ; Medical Research Center, Zhongnan Hospital of Wuhan University , Wuhan , China ; Animal Experiment Center, Wuhan University , Wuhan , China ; Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa, Ontario , Canada
| |
Collapse
|
18
|
Liu JX, Li X, Yan FG, Pan QJ, Yang C, Wu MY, Li G, Liu HF. Protective effect of forsythoside B against lipopolysaccharide-induced acute lung injury by attenuating the TLR4/NF-κB pathway. Int Immunopharmacol 2019; 66:336-346. [DOI: 10.1016/j.intimp.2018.11.033] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Revised: 10/27/2018] [Accepted: 11/19/2018] [Indexed: 12/28/2022]
|
19
|
Monophosphoryl Lipid A and Pam3Cys Prevent the Increase in Seizure Susceptibility and Epileptogenesis in Rats Undergoing Traumatic Brain Injury. Neurochem Res 2018; 43:1978-1985. [PMID: 30173323 DOI: 10.1007/s11064-018-2619-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 07/23/2018] [Accepted: 08/18/2018] [Indexed: 12/19/2022]
Abstract
Five percent of all epilepsy cases are attributed to traumatic brain injury (TBI), which are known as post-traumatic epilepsy (PTE). Finding preventive strategies for PTE is valuable. Remarkable feature of TBI is activation of microglia and subsequent neuroinflammation, which provokes epileptogenesis. The toll-like receptor agonists monophosphoryl lipid A (MPL) and tri-palmitoyl-S-glyceryl-cysteine (Pam3Cys) are safe, well-tolerated and effective adjuvants existing in prophylactic human vaccines. We examined the impact of early injection of MPL and Pam3Cys to rats, on the rate of kindled seizures acquisition following TBI. Rats received a single dose (1 µg/rat) of MPL or Pam3Cys through intracerebroventricular injection. 5 days later, trauma was exerted to temporo-parietal cortex of rats by controlled cortical impact device. After 24 h, traumatic rats underwent amygdala kindling. Brain level of the inflammatory cytokine tumor necrosis factor-alpha (TNF-α) was also measured in traumatic rats by immunoblotting. Compared to non-traumatic (sham-operated) rats, traumatic rats showed three times lower seizure threshold (133 ± 5 µA vs. 416.3 ± 16 µA, p < 0.001); about three times less number of stimuli to become kindled (5 ± 1 vs. 14 ± 2, p < 0.01); longer duration of kindled seizure parameters including entire seizure behavior, generalized seizures, and afterdischarges (p < 0.001); and a two times increase in the TNF-α level. MPL and Pam3Cys did not change kindling rate and the seizure parameters in sham-operated rats. The MPL- and Pam3Cys-pretreated traumatic rats displayed seizure threshold, speed of kindling, and duration of kindled seizure parameters, similar to the non-traumatic rats. Pretreatment by MPL and Pam3Cys prevented the increase in TNF-α level by trauma. Given that MPL and Pam3Cys currently have clinical use as well-tolerated vaccines with reliable safety, they have the potential to be used in prevention of PTE.
Collapse
|
20
|
Yu Y, Shen Q, Lai Y, Park SY, Ou X, Lin D, Jin M, Zhang W. Anti-inflammatory Effects of Curcumin in Microglial Cells. Front Pharmacol 2018; 9:386. [PMID: 29731715 PMCID: PMC5922181 DOI: 10.3389/fphar.2018.00386] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Accepted: 04/04/2018] [Indexed: 11/26/2022] Open
Abstract
Lipoteichoic acid (LTA) induces neuroinflammatory molecules, contributing to the pathogenesis of neurodegenerative diseases. Therefore, suppression of neuroinflammatory molecules could be developed as a therapeutic method. Although previous data supports an immune-modulating effect of curcumin, the underlying signaling pathways are largely unidentified. Here, we investigated curcumin’s anti-neuroinflammatory properties in LTA-stimulated BV-2 microglial cells. Inflammatory cytokine tumor necrosis factor-α [TNF-α, prostaglandin E2 (PGE2), and Nitric Oxide (NO] secretion in LTA-induced microglial cells were inhibited by curcumin. Curcumin also inhibited LTA-induced inducible NO synthases (iNOS) and cyclooxygenase-2 (COX-2) expression. Subsequently, our mechanistic studies revealed that curcumin inhibited LTA-induced phosphorylation of mitogen-activated protein kinase (MAPK) including ERK, p38, Akt and translocation of NF-κB. Furthermore, curcumin induced hemeoxygenase (HO)-1HO-1 and nuclear factor erythroid 2-related factor 2 (Nrf-2) expression in microglial cells. Inhibition of HO-1 reversed the inhibition effect of HO-1 on inflammatory mediators release in LTA-stimulated microglial cells. Taken together, our results suggest that curcumin could be a potential therapeutic agent for the treatment of neurodegenerative disorders via suppressing neuroinflammatory responses.
Collapse
Affiliation(s)
- Yangyang Yu
- Shenzhen University Health Science Center, Shenzhen, China
| | - Qian Shen
- Shenzhen University Health Science Center, Shenzhen, China
| | - Yihong Lai
- Shenzhen University Health Science Center, Shenzhen, China
| | - Sun Y Park
- Bio-IT Fusion Technology Research Institute, Pusan National University, Busan, South Korea
| | - Xingmei Ou
- Shenzhen University Health Science Center, Shenzhen, China
| | - Dongxu Lin
- Shenzhen University Health Science Center, Shenzhen, China
| | - Meiling Jin
- Shenzhen University Health Science Center, Shenzhen, China
| | - Weizhen Zhang
- Shenzhen University Health Science Center, Shenzhen, China
| |
Collapse
|
21
|
Jin M, Park SY, Shen Q, Lai Y, Ou X, Mao Z, Lin D, Yu Y, Zhang W. Anti-neuroinflammatory effect of curcumin on Pam3CSK4-stimulated microglial cells. Int J Mol Med 2017; 41:521-530. [PMID: 29115589 DOI: 10.3892/ijmm.2017.3217] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 10/24/2017] [Indexed: 11/05/2022] Open
Abstract
Curcumin is the main curcuminoid present in Curcuma longa and it has been previously reported to exhibit a wide range of pharmacological activities. In the present study, the inhibitory effects of curcumin on the inflammatory mediators released by Pam3CSK4-stimulated BV-2 microglial cells were investigated. The production of pro-inflammatory mediators and cytokines, including tumor necrosis factor-α (TNF-α) and prostaglandin E2 (PGE2), were measured by enzyme‑linked immunosorbent assay (ELISA). The expression of inflammatory genes, including inducible nitric oxide synthase and cyclooxygenase-2, were further investigated using reverse transcription-quantitative polymerase chain reaction. The effects of curcumin on heme oxygenase-1 (HO-1), nuclear factor (erythroid-derived 2)-like 2 (Nrf2), mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling pathways were analyzed by western blotting. The results revealed that curcumin dose-dependently inhibited Pam3CSK4-induced nitric oxide, PGE2, and TNF-α secretion. Curcumin suppressed the secretion of inflammatory mediators through an increase in the expression of HO-1. Curcumin induced HO-1 transcription and translation through the Nrf2/antioxidant response element signaling pathway. Inhibitory experiments revealed that HO-1 was required for the anti-inflammatory effects of curcumin. Further mechanistic studies demonstrated that curcumin inhibited neuroinflammation by suppressing NF-κB and MAPK signaling pathways in Pam3CSK4-activated microglial cells. The results of the present study suggest that curcumin may be a novel treatment for neuroinflammation-mediated neurodegenerative disorders.
Collapse
Affiliation(s)
- Meiling Jin
- Center for Diabetes, Obesity and Metabolism, Department of Physiology, Shenzhen University Health Science Center, Shenzhen, Guangdong 518060, P.R. China
| | - Sun Young Park
- Bio-IT Fusion Technology Research Institute, Pusan National University, Busan 609-735, Republic of Korea
| | - Qian Shen
- Center for Diabetes, Obesity and Metabolism, Department of Physiology, Shenzhen University Health Science Center, Shenzhen, Guangdong 518060, P.R. China
| | - Yihong Lai
- Center for Diabetes, Obesity and Metabolism, Department of Physiology, Shenzhen University Health Science Center, Shenzhen, Guangdong 518060, P.R. China
| | - Xingmei Ou
- Center for Diabetes, Obesity and Metabolism, Department of Physiology, Shenzhen University Health Science Center, Shenzhen, Guangdong 518060, P.R. China
| | - Zhuo Mao
- Center for Diabetes, Obesity and Metabolism, Department of Physiology, Shenzhen University Health Science Center, Shenzhen, Guangdong 518060, P.R. China
| | - Dongxu Lin
- Center for Diabetes, Obesity and Metabolism, Department of Physiology, Shenzhen University Health Science Center, Shenzhen, Guangdong 518060, P.R. China
| | - Yangyang Yu
- Center for Diabetes, Obesity and Metabolism, Department of Physiology, Shenzhen University Health Science Center, Shenzhen, Guangdong 518060, P.R. China
| | - Weizhen Zhang
- Center for Diabetes, Obesity and Metabolism, Department of Physiology, Shenzhen University Health Science Center, Shenzhen, Guangdong 518060, P.R. China
| |
Collapse
|
22
|
Park SY, Jin ML, Kang NJ, Park G, Choi YW. Anti-inflammatory effects of novel polygonum multiflorum compound via inhibiting NF-κB/MAPK and upregulating the Nrf2 pathways in LPS-stimulated microglia. Neurosci Lett 2017; 651:43-51. [DOI: 10.1016/j.neulet.2017.04.057] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 04/13/2017] [Accepted: 04/27/2017] [Indexed: 01/29/2023]
|
23
|
Involvement of Toll Like Receptor 2 Signaling in Secondary Injury during Experimental Diffuse Axonal Injury in Rats. Mediators Inflamm 2017; 2017:1570917. [PMID: 28293064 PMCID: PMC5331293 DOI: 10.1155/2017/1570917] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 12/17/2016] [Accepted: 01/04/2017] [Indexed: 12/16/2022] Open
Abstract
Treatment of diffuse axonal injury (DAI) remains challenging in clinical practice due to the unclear pathophysiological mechanism. Uncontrolled, excessive inflammation is one of the most recognized mechanisms that contribute to the secondary injury after DAI. Toll like receptor 2 (TLR2) is highlighted for the initiation of a vicious self-propagating inflammatory circle. However, the role and detailed mechanism of TLR2 in secondary injury is yet mostly unknown. In this study, we demonstrated the expression of TLR2 levels in cortex, corpus callosum, and internal capsule and the localization of TLR2 in neurons and glial cells in rat DAI models. Intracerebral knockdown of TLR2 significantly downregulated TLR2 expression, attenuated cortical apoptosis, lessened glial response, and reduced the secondary axonal and neuronal injury in the cortex by inhibiting phosphorylation of mitogen-activated protein kinases (MAPK) including Erk, JNK, and p38, translocation of NF-κB p65 from the cytoplasm to the nucleus, and decreasing levels of proinflammatory cytokines including interleukin-6, interleukin-1β, and tumor necrosis factor-α. On the contrary, administration of TLR2 agonist to DAI rats achieved an opposite effect. Collectively, we demonstrated that TLR2 was involved in mediating secondary injury after DAI by inducing inflammation via the MAPK and NF-κB pathways.
Collapse
|
24
|
Hossain MJ, Tanasescu R, Gran B. Innate immune regulation of autoimmunity in multiple sclerosis: Focus on the role of Toll-like receptor 2. J Neuroimmunol 2016; 304:11-20. [PMID: 28007303 DOI: 10.1016/j.jneuroim.2016.12.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 12/11/2016] [Indexed: 02/06/2023]
Abstract
Innate immunity relies on a set of germline-encoded receptors including Toll-like receptors (TLRs) that enable the host to discriminate between self and non-self. Multiple sclerosis (MS) is an autoimmune inflammatory demyelinating disease of the central nervous system (CNS). Infections are thought to play an important role in disease susceptibility. The role of innate immunity in MS has been recently appreciated. TLR2, a member of the TLR family, forms heterodimers with either TLR1 or TLR6 and detects a wide range of microbial as well as self-derived molecular structures. It may thus be important both in fighting infection and in activating autoimmunity. In this review, we discuss innate regulation of autoimmunity in MS with a focus on the role of TLR2 signaling.
Collapse
Affiliation(s)
- Md Jakir Hossain
- Division of Clinical Neuroscience, University of Nottingham, School of Medicine, Queen's Medical Centre, Nottingham NG7 2UH, United Kingdom
| | - Radu Tanasescu
- Division of Clinical Neuroscience, University of Nottingham, School of Medicine, Queen's Medical Centre, Nottingham NG7 2UH, United Kingdom; Department of Neurology, Neurosurgery and Psychiatry, University of Medicine and Pharmacy Carol Davila, Colentina Hospital, Bucharest, Romania
| | - Bruno Gran
- Division of Clinical Neuroscience, University of Nottingham, School of Medicine, Queen's Medical Centre, Nottingham NG7 2UH, United Kingdom; Department of Neurology, Nottingham University Hospitals NHS Trust, Nottingham NG7 2UH, United Kingdom.
| |
Collapse
|
25
|
Li W, Jiang D, Li Q, Yao S, Sun X, Yang Y, Meng Z, Liu W. Lipopolysaccharide–induced preconditioning protects against traumatic spinal cord injury by upregulating Nrf2 expression in rats. Life Sci 2016; 162:14-20. [DOI: 10.1016/j.lfs.2016.08.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Revised: 07/31/2016] [Accepted: 08/08/2016] [Indexed: 11/29/2022]
|
26
|
Acioglu C, Mirabelli E, Baykal AT, Ni L, Ratnayake A, Heary RF, Elkabes S. Toll like receptor 9 antagonism modulates spinal cord neuronal function and survival: Direct versus astrocyte-mediated mechanisms. Brain Behav Immun 2016; 56:310-24. [PMID: 27044334 DOI: 10.1016/j.bbi.2016.03.027] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 03/16/2016] [Accepted: 03/31/2016] [Indexed: 12/31/2022] Open
Abstract
Toll like receptors (TLRs) are expressed by cells of the immune system and mediate the host innate immune responses to pathogens. However, increasing evidence indicates that they are important contributors to central nervous system (CNS) function in health and in pathological conditions involving sterile inflammation. In agreement with this idea, we have previously shown that intrathecal administration of a TLR9 antagonist, cytidine-phosphate-guanosine oligodeoxynucleotide 2088 (CpG ODN 2088), ameliorates the outcomes of spinal cord injury (SCI). Although these earlier studies showed a marked effect of CpG ODN 2088 on inflammatory cells, the expression of TLR9 in spinal cord (SC) neurons and astrocytes suggested that the antagonist exerts additional effects through direct actions on these cells. The current study was undertaken to assess the direct effects of CpG ODN 2088 on SC neurons, astrocytes and astrocyte-neuron interactions, in vitro. We report, for the first time, that inhibition of TLR9 in cultured SC neurons alters their function and confers protection against kainic acid (KA)-induced excitotoxic death. Moreover, the TLR9 antagonist attenuated the KA-elicited endoplasmic reticulum (ER) stress response in neurons, in vitro. CpG ODN 2088 also reduced the transcript levels and release of chemokine (C-X-C) motif ligand 1 (CXCL1) and monocyte chemotactic protein 1 (MCP-1) by astrocytes and it diminished interleukin-6 (IL-6) release without affecting transcript levels in vitro. Conditioned medium (CM) of CpG ODN 2088-treated astroglial cultures decreased the viability of SC neurons compared to CM of vehicle-treated astrocytes. However, this toxicity was not observed when astrocytes were co-cultured with neurons. Although CpG ODN 2088 limited the survival-promoting effects of astroglia, it did not reduce neuronal viability compared to controls grown in the absence of astrocytes. We conclude that the TLR9 antagonist acts directly on both SC neurons and astrocytes. Neuronal TLR9 antagonism confers protection against excitotoxic death. It is likely that this neuroprotection is partly due to the attenuation of the ER stress response provoked by excitotoxicity. Although CpG ODN 2088 limits the supportive effects of astrocytes on neurons, it could potentially exert beneficial effects by decreasing the release of pro-inflammatory cytokines and chemokines by astroglia. These findings highlight the multiple roles of TLR9 in the SC and have implications for pathological conditions including SCI where excitotoxicity and neuroinflammation play a prominent role in neuronal degeneration.
Collapse
Affiliation(s)
- Cigdem Acioglu
- Department of Neurological Surgery, Reynolds Family Spine Laboratory, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, United States; Department of Molecular Biology and Genetics, Faculty of Arts and Sciences, Kilis 7 Aralik University, 79000 Kilis, Turkey
| | - Ersilia Mirabelli
- Department of Neurological Surgery, Reynolds Family Spine Laboratory, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, United States; Graduate School of Biomedical Sciences, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, United States
| | - Ahmet Tarik Baykal
- Department of Medical Biochemistry, School of Medicine, Acibadem University, 34752 Istanbul, Turkey
| | - Li Ni
- Department of Neurological Surgery, Reynolds Family Spine Laboratory, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, United States
| | - Ayomi Ratnayake
- Department of Neurological Surgery, Reynolds Family Spine Laboratory, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, United States
| | - Robert F Heary
- Department of Neurological Surgery, Reynolds Family Spine Laboratory, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, United States
| | - Stella Elkabes
- Department of Neurological Surgery, Reynolds Family Spine Laboratory, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, United States.
| |
Collapse
|
27
|
TLR2/4 deficiency prevents oxygen-induced vascular degeneration and promotes revascularization by downregulating IL-17 in the retina. Sci Rep 2016; 6:27739. [PMID: 27297042 PMCID: PMC4906284 DOI: 10.1038/srep27739] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 05/23/2016] [Indexed: 12/25/2022] Open
Abstract
Vascular degeneration is a critical pathological process in many human degenerative diseases, which need efficient ways to revascularization. However, little is known about cellular and molecular mechanisms that are used during vascular degeneration and revascularization. Here, we show that Toll-like receptor 2 and 4 (TLR2/4) double deficiency suppressed hyperoxia induced retinal vessel regression in an oxygen-induced retinopathy (OIR) model. Notably, the TLR2/4−/− mice experienced more revascularization after reduced vessel regression compared with wild-type mice, accompanied with less activation of glial cells. Mechanistically, TLR2/4 activation can tip the balance between Th17 cells and regulatory T cells towards Th17 cells, a critical source of the IL-17A. Less migration and infiltration of IL-17A-expressing proinflammatory cells but elevated regulatory T cells were observed in OIR-retinae from TLR2/4−/− mice. Coincidentally, TLR2/4 deficiency suppressed IL-17A production and increased expressions of anti-inflammatory genes. Furthermore, IL-17A promoted activation of glial cells. IL-17A blockade using a neutralizing antibody alleviated retinal cell apoptosis and glial activation in C57/B6-OIR mice, demonstrating the important role of IL-17A pathway in glial function during revascularization. Thus TLR2/4-mediated IL-17A inflammatory signaling is involved in vessel degeneration and revascularization, indicating that modulation of the TLR2/4-IL-17A pathway may be a novel therapeutic strategy for degenerative diseases.
Collapse
|
28
|
Hu QP, Mao DA. Histone deacetylase inhibitor SAHA attenuates post-seizure hippocampal microglia TLR4/MYD88 signaling and inhibits TLR4 gene expression via histone acetylation. BMC Neurosci 2016; 17:22. [PMID: 27193049 PMCID: PMC4872358 DOI: 10.1186/s12868-016-0264-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 05/11/2016] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Epilepsy is a common neurological disorder characterized by recurrent unprovoked seizures. Seizure-induced TLR4/MYD88 signaling plays a critical role in activating microglia and triggering neuron apoptosis. SAHA is a histone deacetylase inhibitor that regulates gene expression by increasing chromatin histone acetylation. In this study, we investigated the role of SAHA in TLR4/MYD88 signaling in a rat seizure model. RESULTS Sprague-Dawley rats with kainic acid (KA)-induced seizures were treated with SAHA. The expression of TLR4, MYD88, NF-κB P65 and IL-1β in hippocampus was detected at hour 2 and 6 and day 1, 2, and 3 post seizure. SAHA pretreatment increased seizure latency and decreased seizure scores. The expression levels of TLR4, MYD88, NF-κB and IL-1β increased significantly in both activated microglia and apoptotic neurons after KA treatment. The effects were attenuated by SAHA. Chromatin immunoprecipitation assays indicated that the H3 histone acetylation levels significantly decreased while H3K9 levels significantly increased in the KA treatment group. The H3 and H3K9 acetylation levels returned to control levels after SAHA (50 mg/kg) pretreatment. There was a positive correlation between the expression of TLR4 and the acetylation levels of H3K9. CONCLUSIONS Histone deacetylase inhibitor SAHA can suppress seizure-induced TLR4/MYD88 signaling and inhibit TLR4 gene expression through histone acetylation regulation. This suggests that SAHA may protect against seizure-induced brain damage.
Collapse
Affiliation(s)
- Qing-Peng Hu
- Department of Pediatrics, The Second Xiang-Ya Hospital, Central South University, 139 Middle Renmin Road, Changsha, 410011, Hunan, China
| | - Ding-An Mao
- Department of Pediatrics, The Second Xiang-Ya Hospital, Central South University, 139 Middle Renmin Road, Changsha, 410011, Hunan, China.
| |
Collapse
|
29
|
Singer BH, Newstead MW, Zeng X, Cooke CL, Thompson RC, Singer K, Ghantasala R, Parent JM, Murphy GG, Iwashyna TJ, Standiford TJ. Cecal Ligation and Puncture Results in Long-Term Central Nervous System Myeloid Inflammation. PLoS One 2016; 11:e0149136. [PMID: 26862765 PMCID: PMC4749127 DOI: 10.1371/journal.pone.0149136] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 01/26/2016] [Indexed: 12/24/2022] Open
Abstract
Survivors of sepsis often experience long-term cognitive and functional decline. Previous studies utilizing lipopolysaccharide injection and cecal ligation and puncture in rodent models of sepsis have demonstrated changes in depressive-like behavior and learning and memory after sepsis, as well as evidence of myeloid inflammation and cytokine expression in the brain, but the long-term course of neuroinflammation after sepsis remains unclear. Here, we utilize cecal ligation and puncture with greater than 80% survival as a model of sepsis. We found that sepsis survivor mice demonstrate deficits in extinction of conditioned fear, but no acquisition of fear conditioning, nearly two months after sepsis. These cognitive changes occur in the absence of neuronal loss or changes in synaptic density in the hippocampus. Sepsis also resulted in infiltration of monocytes and neutrophils into the CNS at least two weeks after sepsis in a CCR2 independent manner. Cellular inflammation is accompanied by long-term expression of pro-inflammatory cytokine and chemokine genes, including TNFα and CCR2 ligands, in whole brain homogenates. Gene expression analysis of microglia revealed that while microglia do express anti-microbial genes and damage-associated molecular pattern molecules of the S100A family of genes at least 2 weeks after sepsis, they do not express the cytokines observed in whole brain homogenates. Our results indicate that in a naturalistic model of infection, sepsis results in long-term neuroinflammation, and that this sustained inflammation is likely due to interactions among multiple cell types, including resident microglia and peripherally derived myeloid cells.
Collapse
Affiliation(s)
- Benjamin H. Singer
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- * E-mail:
| | - Michael W. Newstead
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Xianying Zeng
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Christopher L. Cooke
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Robert C. Thompson
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Kanakadurga Singer
- Department of Pediatrics, Division of Endocrinology and Metabolism, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Ramya Ghantasala
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Jack M. Parent
- Department of Neurology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Geoffrey G. Murphy
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Theodore J. Iwashyna
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Center for Clinical Management Research, VA Ann Arbor Health System, Ann Arbor, Michigan, United States of America
| | - Theodore J. Standiford
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| |
Collapse
|
30
|
Eslami M, Sayyah M, Soleimani M, Alizadeh L, Hadjighassem M. Lipopolysaccharide preconditioning prevents acceleration of kindling epileptogenesis induced by traumatic brain injury. J Neuroimmunol 2015; 289:143-51. [PMID: 26616884 DOI: 10.1016/j.jneuroim.2015.11.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 10/31/2015] [Accepted: 11/03/2015] [Indexed: 02/08/2023]
Abstract
10-20% of symptomatic epilepsies are post-traumatic. We examined effect of LPS preconditioning on epileptogenesis after controlled cortical impact (CCI). LPS (0.01, 0.1 and 0.5 mg/kg) was injected i.p. to rats 5 days before induction of CCI to parieto-temporal cortex. Kindling started 24h after CCI by i.p. injection of 30 mg/kg of pentylenetetrazole every other day until manifestation of 3 consecutive generalized seizures. CCI injury accelerated the rate of kindled seizures acquisition. LPS (0.1 and 0.5 mg/kg) prevented the acceleration of kindling. LPS preconditioning significantly decreased IL-1β and TNF-α over-expression and the number of damaged neurons in the hippocampus of traumatic rats.
Collapse
Affiliation(s)
- Mansoureh Eslami
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran; Department of Neuroscience, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran; Department of Physiology and Pharmacology, Pasteur Institute of Iran, Tehran, Iran; Department of Basic Sciences, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Sayyah
- Department of Physiology and Pharmacology, Pasteur Institute of Iran, Tehran, Iran.
| | - Mansoureh Soleimani
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | | | - Mahmoudreza Hadjighassem
- Brain and Spinal cord injury Research Center, Neuroscience Institute, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran; Department of Neuroscience, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran.
| |
Collapse
|