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Yu R, Ma C, Li G, Xu J, Feng D, Lan X. Inhibition of Toll-Like Receptor 4 Signaling Pathway Accelerates the Repair of Avascular Necrosis of Femoral Epiphysis through Regulating Macrophage Polarization in Perthes Disease. Tissue Eng Regen Med 2023; 20:489-501. [PMID: 37041432 PMCID: PMC10219917 DOI: 10.1007/s13770-023-00529-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/18/2023] [Accepted: 02/13/2023] [Indexed: 04/13/2023] Open
Abstract
BACKGROUND Legg-Calvé-Perthes disease (LCPD) is still a refractory disease in children's orthopedics. With the introduction of the concept of "osteoimmunology", the immune-inflammatory mechanisms between bone and immune system have become a research focus of LCPD. However, few studies have reported on the pathological role of inflammation-related receptors such as toll-like receptors (TLRs) as well as immune cells such as macrophages in LCPD. This study was for investigating the mechanism of TLR4 signaling pathway on the direction of macrophage polarization and the repair of avascular necrosis of femoral epiphysis in LCPD. METHODS With GSE57614 and GSE74089, differentially expressed genes were screened. Through enrichment analysis and protein-protein interaction network, the functions of TLR4 were explored. Furthermore, immunohistochemistry, enzyme-linked immunosorbent assay (ELISA), hematoxylin & eosin (H&E) staining, micro-CT, tartrate-resistant acid phosphatase (TRAP) dyeing and western blotting were performed for determining the influences of TAK-242 (a TLR4 inhibitor) on the repair of avascular necrosis of femoral epiphysis in rat models. RESULTS Totally 40 co-expression genes were screened as well as enriched in TLR4 signaling pathway. Immunohistochemistry and ELISA analyses certified that TLR4 facilitated macrophage polarization toward the M1 phenotype and prevented macrophage polarization toward the M2 phenotype. Besides, the results of H&E and TRAP staining, micro-CT, and western blotting showed that TAK-242 can inhibit osteoclastogenesis and promote osteogenesis. CONCLUSION Inhibition of TLR4 signaling pathway accelerated the repair of avascular necrosis of femoral epiphysis by regulating macrophage polarization in LCPD.
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Affiliation(s)
- Ronghui Yu
- Department of Orthopedics, First Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Cong Ma
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Guoyong Li
- Department of Orthopedics, First Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Jianyun Xu
- Department of Orthopedics, First Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Dan Feng
- Department of General Surgery, Jiangxi Provincial Children's Hospital, Nanchang, 330046, Jiangxi, China
| | - Xia Lan
- Department of Orthopedics, First Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, China.
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Ma Q, Deng P, Lin M, Yang L, Li L, Guo L, Zhang L, He M, Lu Y, Pi H, Zhang Y, Yu Z, Chen C, Zhou Z. Long-term bisphenol A exposure exacerbates diet-induced prediabetes via TLR4-dependent hypothalamic inflammation. JOURNAL OF HAZARDOUS MATERIALS 2021; 402:123926. [PMID: 33254826 DOI: 10.1016/j.jhazmat.2020.123926] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 09/02/2020] [Accepted: 09/03/2020] [Indexed: 06/12/2023]
Abstract
Bisphenol A (BPA), an environmental endocrine-disrupting compound, has been revealed associated with metabolic disorders such as obesity, prediabetes, and type 2 diabetes (T2D). However, its underlying mechanisms are still not fully understood. Here, we provide new evidence that BPA is a risk factor for T2D from a case-control study. To explore the detailed mechanisms, we used two types of diet models, standard diet (SD) and high-fat diet (HFD), to study the effects of long-term BPA exposure on prediabetes in 4-week-old mice. We found that BPA exposure for 12 weeks exacerbated HFD-induced prediabetic symptoms. Female mice showed increased body mass, serum insulin level, and impaired glucose tolerance, while male mice only exhibited impaired glucose tolerance. No change was found in SD-fed mice. Besides, BPA exposure enhanced astrocyte-dependent hypothalamic inflammation in both male and female mice, which impaired proopiomelanocortin (POMC) neuron functions. Moreover, eliminating inflammation by toll-like receptor 4 (TLR4) knockout significantly abolished the effects of BPA on the hypothalamus and diet-induced prediabetes. Taken together, our data establish a key role for TLR4-dependent hypothalamic inflammation in regulating the effects of BPA on prediabetes.
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Affiliation(s)
- Qinlong Ma
- Department of Occupational Health, Army Medical University (Former Name: Third Military Medical University), Chongqing 400038, People's Republic of China
| | - Ping Deng
- Department of Occupational Health, Army Medical University (Former Name: Third Military Medical University), Chongqing 400038, People's Republic of China
| | - Min Lin
- Department of Occupational Health, Army Medical University (Former Name: Third Military Medical University), Chongqing 400038, People's Republic of China
| | - Lingling Yang
- Department of Occupational Health, Army Medical University (Former Name: Third Military Medical University), Chongqing 400038, People's Republic of China
| | - Le Li
- Department of Health Management Center, Southwest Hospital, Army Medical University (Former Name: Third Military Medical University), Chongqing 400038, People's Republic of China
| | - Lu Guo
- Department of Neurology, Daping Hospital, Army Medical University (Former Name: Third Military Medical University), Chongqing 400042, People's Republic of China
| | - Lei Zhang
- Department of Occupational Health, Army Medical University (Former Name: Third Military Medical University), Chongqing 400038, People's Republic of China
| | - Mindi He
- Department of Occupational Health, Army Medical University (Former Name: Third Military Medical University), Chongqing 400038, People's Republic of China
| | - Yonghui Lu
- Department of Occupational Health, Army Medical University (Former Name: Third Military Medical University), Chongqing 400038, People's Republic of China
| | - Huifeng Pi
- Department of Occupational Health, Army Medical University (Former Name: Third Military Medical University), Chongqing 400038, People's Republic of China
| | - Yanwen Zhang
- Department of Occupational Health, Army Medical University (Former Name: Third Military Medical University), Chongqing 400038, People's Republic of China
| | - Zhengping Yu
- Department of Occupational Health, Army Medical University (Former Name: Third Military Medical University), Chongqing 400038, People's Republic of China
| | - Chunhai Chen
- Department of Occupational Health, Army Medical University (Former Name: Third Military Medical University), Chongqing 400038, People's Republic of China.
| | - Zhou Zhou
- Department of Environmental Medicine, and Department of Emergency Medicine of First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China.
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Chen LC, Shibu MA, Liu CJ, Han CK, Ju DT, Chen PY, Viswanadha VP, Lai CH, Kuo WW, Huang CY. ERK1/2 mediates the lipopolysaccharide-induced upregulation of FGF-2, uPA, MMP-2, MMP-9 and cellular migration in cardiac fibroblasts. Chem Biol Interact 2019; 306:62-69. [PMID: 30980805 DOI: 10.1016/j.cbi.2019.04.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 03/08/2019] [Accepted: 04/08/2019] [Indexed: 12/31/2022]
Abstract
Myocardial fibrosis is a critical event during septic shock. Upregulation in the fibrosis signaling cascade proteins such as fibroblast growth factor (FGF), urokinase plasminogen activator (uPA), tissue plasminogen activator (tPA) and activation of matrix metalloproteinases (MMPs) are widely associated with the development of myocardial infarction, dilated cardiomyopathy, cardiac fibrosis and heart failure. However, evidences suggest that the common upstream mediators of fibrosis cascade play little role in cardiac fibrosis induced by LPS; further, it is unknown if LPS directly triggers the expressions and/or activity of FGF-2, uPA, tPA, MMP-2 and MMP-9 in cardiac fibroblasts. In the present study, we treated primary cultures of cardiac fibroblasts with LPS to explore whether LPS upregulates FGF-2, uPA, tPA, MMP-2, MMP-9 and enhance cellular migration. Further the precise molecular and cellular mechanisms behind these LPS induced responses were identified. Inhibition assays on MAPKs using U0126 (ERK1/2 inhibitor), SB203580 (p38 MAPK inhibitor), SP600125 (JNK1/2 inhibitor), CsA (calcineurin inhibitor) and QNZ (NFκB inhibitor) show that LPS-induced upregulation of FGF-2, uPA, MMP-2 and MMP-9 in cardiac fibroblasts was mediated through ERK1/2 signaling. Collectively, our results provide a link between LPS-induced cardiac dysfunction and ERK1/2 signaling pathway and thereby implies ERK1/2 as a possible target to regulate LPS induced upregulation of FGF-2, uPA, MMP-2, MMP-9 and cellular migration in cardiac fibroblasts.
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Affiliation(s)
- Liang-Chi Chen
- Department of Pathology, China Medical University Hospital, Taichung, Taiwan
| | - Marthandam Asokan Shibu
- Medical Research Center for Exosome and Mitochondria Related Diseases, China Medical University and Hospital, Taichung, Taiwan
| | - Chung-Jung Liu
- Division of Gastroenterology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Chien-Kuo Han
- Department of Biotechnology, Asia University, Taichung, Taiwan
| | - Da-Tong Ju
- Department of Neurological Surgery,Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Pei-Yu Chen
- Department of Pathology, China Medical University Hospital, Taichung, Taiwan
| | | | - Chao-Hung Lai
- Division of Cardiology, Department of Internal Medicine, Taichung Armed Force General Hospital, Taichung, Taiwan
| | - Wei-Wen Kuo
- Department of Biological Science and Technology, China Medical University, Taichung, Taiwan
| | - Chih-Yang Huang
- Department of Biotechnology, Asia University, Taichung, Taiwan; College of Medicine, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Tzu Chi University, Hualien, Taiwan; Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan.
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Koenig A, Buskiewicz I, Huber SA. Age-Associated Changes in Estrogen Receptor Ratios Correlate with Increased Female Susceptibility to Coxsackievirus B3-Induced Myocarditis. Front Immunol 2017; 8:1585. [PMID: 29201031 PMCID: PMC5696718 DOI: 10.3389/fimmu.2017.01585] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 11/03/2017] [Indexed: 01/01/2023] Open
Abstract
Sexual bias is a hallmark in various diseases. This review evaluates sexual dimorphism in clinical and experimental coxsackievirus B3 (CVB3) myocarditis, and how sex bias in the experimental disease changes with increased age. Coxsackieviruses are major causes of viral myocarditis, an inflammation of the heart muscle, which is more frequent and severe in men than women. Young male mice infected with CVB3 develop heart-specific autoimmunity and severe myocarditis. Females infected during estrus (high estradiol) develop T-regulatory cells and when infected during diestrus (low estradiol) develop autoimmunity similar to males. During estrus, protection depends on estrogen receptor alpha (ERα), which promotes type I interferon, activation of natural killer/natural killer T cells and suppressor cell responses. Estrogen receptor beta has opposing effects to ERα and supports pro-inflammatory immunity. However, the sexual dimorphism of the disease is significantly ameliorated in aged animals when old females become as susceptible as males. This correlates to a selective loss of the ERα that is required for immunosuppression. Therefore, sex-associated hormones control susceptibility in the virus-mediated disease, but their impact can alter with the age and physiological stage of the individual.
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Affiliation(s)
- Andreas Koenig
- Department of Pathology, University of Vermont, Burlington, VT, United States
| | - Iwona Buskiewicz
- Department of Pathology, University of Vermont, Burlington, VT, United States
| | - Sally A Huber
- Department of Pathology, University of Vermont, Burlington, VT, United States
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Chiu YH, Ku PM, Cheng YZ, Li Y, Cheng JT, Niu HS. Phosphorylation of signal transducer and activator of transcription 3 induced by hyperglycemia is different with that induced by lipopolysaccharide or erythropoietin via receptor‑coupled signaling in cardiac cells. Mol Med Rep 2017; 17:1311-1320. [PMID: 29115516 DOI: 10.3892/mmr.2017.7973] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 10/25/2017] [Indexed: 11/06/2022] Open
Abstract
The signal transducer and activator of transcription 3 (STAT3) is known to be involved in hypertrophy and fibrosis in cardiac dysfunction. The activation of STAT3 via the phosphorylation of STAT3 is required for the production of functional activity. It has been established that lipopolysaccharide (LPS)‑induced phosphorylation of STAT3 in cardiomyocytes primarily occurs through a direct receptor‑mediated action. This effect is demonstrated to be produced rapidly. STAT3 in cardiac fibrosis of diabetes is induced by high glucose through promotion of the STAT3‑associated signaling pathway. However, the time schedule for STAT3 activation between LPS and high glucose appears to be different. Therefore, the difference in STAT3 activation between LPS and hyperglycemia in cardiomyocytes requires elucidation. The present study investigated the phosphorylation of STAT3 induced by LPS and hyperglycemia in the rat cardiac cell line H9c2. Additionally, phosphorylation of STAT3 induced by erythropoietin (EPO) via receptor activation was compared. Then, the downstream signals for fibrosis, including the connective tissue growth factor (CTGF) and matrix metalloproteinase (MMP)‑9, were determined using western blotting, while the mRNA levels were quantified. LPS induced a rapid elevation of STAT3 phosphorylation in H9c2 cells within 30 min, similar to that produced by EPO. However, LPS or EPO failed to modify the mRNA level of STAT3, and/or the downstream signals for fibrosis. High glucose increased STAT3 phosphorylation to be stable after a long period of incubation. Glucose incubation for 24 h may augment the STAT3 expression in a dose‑dependent manner. Consequently, fibrosis‑associated signals, including CTGF and MMP‑9 protein, were raised in parallel. In the presence of tiron, an antioxidant, these changes by hyperglycemia were markedly reduced, demonstrating the mediation of oxidative stress. Therefore, LPS‑ or EPO‑induced STAT3 phosphorylation is different compared with that caused by high glucose in H9c2 cells. Sustained activation of STAT3 by hyperglycemia may promote the expression of fibrosis‑associated signals, including CTGF and MMP‑9, in H9c2 cells. Therefore, regarding the cardiac dysfunctions associated with diabetes and/or hyperglycemia, the identification of nuclear STAT3 may be more reliable compared with the assay of phosphorylated STAT3 in cardiac cells.
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Affiliation(s)
- Yu-Hsin Chiu
- Division of Infectious Diseases, Chi‑Mei Medical Center‑Liouying, Tainan 73601, Taiwan, R.O.C
| | - Po-Ming Ku
- Cardiovascular Center, Department of Internal Medicine, Chi‑Mei Medical Center‑Liouying, Tainan 73601, Taiwan, R.O.C
| | - Yung-Ze Cheng
- Department of Emergency Medicine, Chi‑Mei Medical Center, Tainan 71003, Taiwan, R.O.C
| | - Yingxiao Li
- Department of Medical Research, Chi‑Mei Medical Center, Tainan 71003, Taiwan, R.O.C
| | - Juei-Tang Cheng
- Department of Medical Research, Chi‑Mei Medical Center, Tainan 71003, Taiwan, R.O.C
| | - Ho-Shan Niu
- Department of Nursing, Tzu Chi University of Science and Technology, Hualien 97005, Taiwan, R.O.C
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Rokade S, Kishore U, Madan T. Surfactant protein D regulates murine testicular immune milieu and sperm functions. Am J Reprod Immunol 2017; 77. [PMID: 28054406 DOI: 10.1111/aji.12629] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 12/09/2016] [Indexed: 12/29/2022] Open
Abstract
PROBLEM Surfactant protein D (SP-D), a pattern recognition protein that regulates inflammation and immune homoeostasis, is expressed by testicular germ cells under the influence of testosterone. This study investigates the role of SP-D in testicular immune privilege and sperm functions. METHOD OF STUDY Testicular levels of cytokines and immunoregulatory molecules were evaluated in lipopolysaccharide (LPS)-challenged SP-D gene knockout mice (SP-D-/- ). Further, sperm functions were assessed by computer-assisted sperm analyser (CASA) and in vitro capacitation. The effect of a recombinant fragment of human SP-D (rhSP-D) on LPS-induced testicular inflammation and sperm motility was assessed in wild-type (WT) mice. RESULT Endogenous absence of SP-D led to significantly increased testicular levels of immunosuppressive molecules, viz. serpina3, TGF-β1 and IL-10, and reduced levels of immune cell activation markers, CD86, IL-2 and ITGAX. These compensatory mechanisms resulted in markedly blunted levels of TNF-α, IL-12p40, MIP-1α, G-CSF and IL-6 in response to LPS challenge. Notably, exogenous supplementation of rhSP-D salvaged the WT mice from LPS-induced pro-inflammatory immune response and impairment of sperm motility by upregulating the levels of TGF-β1 and IL-10. CONCLUSION The study highlights the involvement of SP-D in maintenance of testicular immune privilege and its indirect contribution to male fertility.
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Affiliation(s)
- Sushama Rokade
- Department of Innate Immunity, National Institute for Research in Reproductive Health (NIRRH), Indian Council of Medical Research (ICMR), Parel, Mumbai, India
| | - Uday Kishore
- Biosciences, College of Health and Life Sciences, Brunel University London, Uxbridge, UK
| | - Taruna Madan
- Department of Innate Immunity, National Institute for Research in Reproductive Health (NIRRH), Indian Council of Medical Research (ICMR), Parel, Mumbai, India
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Chen CW, Chen CC, Jian CY, Lin PH, Chou JC, Teng HS, Hu S, Lieu FK, Wang PS, Wang SW. Attenuation of exercise effect on inflammatory responses via novel role of TLR4/PI3K/Akt signaling in rat splenocytes. J Appl Physiol (1985) 2016; 121:870-877. [DOI: 10.1152/japplphysiol.00393.2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 08/16/2016] [Indexed: 01/07/2023] Open
Abstract
Moderate exercise diminishes proinflammation cytokine production in various types of immune cells, but the intracellular signaling pathways involved are not completely understood. Phosphoinositide 3-kinase (PI3K)/Akt, a crucial downstream protein of toll-like receptor 4 (TLR4), may modulate inflammation. The present study aimed to investigate the effects of exercises on lipopolysaccharide (LPS)-stimulated inflammatory response in splenocytes and to explore potential mechanisms of the PI3K/Akt pathway. Male rats were divided into sedentary and exercise groups. Animals in the exercise group underwent endurance training 30 min/day, 7 days/wk, at the speed of 20 m/min on a treadmill for 1 wk. Here, we showed that exercise 1) attenuated TLR4, 2) increased PI3K/phospho-Akt (p-Akt), and 3) diminished phospho-nuclear factor-κB (p-NF-κB) expression. In addition, administration of splenocytes isolated from trained rats with LPS in vitro showed 1) reduced tumor necrosis factor (TNF-α), interleukin 6 (IL-6), and nitric oxide secretion and 2) decreased splenocyte proliferation. The plasma corticosterone (CCS) level in the exercise group was higher than that in the sedentary group. We confirmed that CCS down-regulated TNF-α and IL-6 secretion in response to LPS in rat splenocytes. Dexamethasone also significantly attenuated LPS-evoked release of TNF-α and IL-6 in a dose-dependent manner. These findings suggested that exercise dampened the secretion of inflammation mediators probably through partial inhibition of TLR4 and p-NF-κB and activation of PI3K/p-Akt expression in the spleen.
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Affiliation(s)
- Chien-Wei Chen
- Department of Physiology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Chih-Chieh Chen
- Department of Physiology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Cai-Yun Jian
- Department of Physiology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Po-Han Lin
- Department of Physiology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Jou-Chun Chou
- Medical Center of Aging Research, China Medical University Hospital, Taichung, Taiwan
| | - Hsueh-Su Teng
- Department of Rehabilitation, Cheng Hsin General Hospital, Taipei, Taiwan
| | - Sindy Hu
- Aesthetic Medical Center, Department of Dermatology, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- Department of Medicine, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Fu-Kong Lieu
- Department of Rehabilitation, Cheng Hsin General Hospital, Taipei, Taiwan
| | - Paulus S. Wang
- Department of Physiology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Medical Center of Aging Research, China Medical University Hospital, Taichung, Taiwan
- Department of Biotechnology, College of Health Science, Asia University, Taichung, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan; and
| | - Shyi-Wu Wang
- Aesthetic Medical Center, Department of Dermatology, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- Department of Physiology and Pharmacology, College of Medicine, Chang Gung University, Taoyuan, Taiwan
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Marinelli C, Di Liddo R, Facci L, Bertalot T, Conconi MT, Zusso M, Skaper SD, Giusti P. Ligand engagement of Toll-like receptors regulates their expression in cortical microglia and astrocytes. J Neuroinflammation 2015; 12:244. [PMID: 26714634 PMCID: PMC4696218 DOI: 10.1186/s12974-015-0458-6] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 12/15/2015] [Indexed: 12/13/2022] Open
Abstract
Background Toll-like receptor (TLR) activation on microglia and astrocytes are key elements in neuroinflammation which accompanies a number of neurological disorders. While TLR activation on glia is well-established to up-regulate pro-inflammatory mediator expression, much less is known about how ligand engagement of one TLR may affect expression of other TLRs on microglia and astrocytes. Methods In the present study, we evaluated the effects of agonists for TLR2 (zymosan), TLR3 (polyinosinic-polycytidylic acid (poly(I:C)), a synthetic analogue of double-stranded RNA) and TLR4 (lipopolysaccaride (LPS)) in influencing expression of their cognate receptor as well as that of the other TLRs in cultures of rat cortical purified microglia (>99.5 %) and nominally microglia-free astrocytes. Elimination of residual microglia (a common contaminant of astrocyte cultures) was achieved by incubation with the lysosomotropic agent l-leucyl-l-leucine methyl ester (L-LME). Results Flow cytometric analysis confirmed the purity (essentially 100 %) of the obtained microglia, and up to 5 % microglia contamination of astrocytes. L-LME treatment effectively removed microglia from the latter (real-time polymerase chain reaction). The three TLR ligands robustly up-regulated gene expression for pro-inflammatory markers (interleukin-1 and interleukin-6, tumor necrosis factor) in microglia and enriched, but not purified, astrocytes, confirming cellular functionality. LPS, zymosan and poly(I:C) all down-regulated TLR4 messenger RNA (mRNA) and up-regulated TLR2 mRNA at 6 and 24 h. In spite of their inability to elaborate pro-inflammatory mediator output, the nominally microglia-free astrocytes (>99 % purity) also showed similar behaviours to those of microglia, as well as changes in TLR3 gene expression. LPS interaction with TLR4 activates downstream mitogen-activated protein kinase and nuclear factor-κB signalling pathways and subsequently causes inflammatory mediator production. The effects of LPS on TLR2 mRNA in both cell populations were antagonized by a nuclear factor-κB inhibitor. Conclusions TLR2 and TLR4 activation in particular, in concert with microglia and astrocytes, comprise key elements in the initiation and maintenance of neuropathic pain. The finding that both homologous (zymosan) and heterologous (LPS, poly(I:C)) TLR ligands are capable of regulating TLR2 gene expression, in particular, may have important implications in understanding the relative contributions of different TLRs in neurological disorders associated with neuroinflammation. Electronic supplementary material The online version of this article (doi:10.1186/s12974-015-0458-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Carla Marinelli
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Largo "E. Meneghetti" 2, 35131, Padua, Italy.
| | - Rosa Di Liddo
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Largo "E. Meneghetti" 2, 35131, Padua, Italy.
| | - Laura Facci
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Largo "E. Meneghetti" 2, 35131, Padua, Italy.
| | - Thomas Bertalot
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Largo "E. Meneghetti" 2, 35131, Padua, Italy.
| | - Maria Teresa Conconi
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Largo "E. Meneghetti" 2, 35131, Padua, Italy.
| | - Morena Zusso
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Largo "E. Meneghetti" 2, 35131, Padua, Italy.
| | - Stephen D Skaper
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Largo "E. Meneghetti" 2, 35131, Padua, Italy.
| | - Pietro Giusti
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Largo "E. Meneghetti" 2, 35131, Padua, Italy.
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LI FANGFANG, YUAN YUAN, LIU YUAN, WU QINGQING, JIAO RONG, YANG ZHENG, ZHOU MENGQIAO, TANG QIZHU. Pachymic acid protects H9c2 cardiomyocytes from lipopolysaccharide-induced inflammation and apoptosis by inhibiting the extracellular signal-regulated kinase 1/2 and p38 pathways. Mol Med Rep 2015; 12:2807-13. [DOI: 10.3892/mmr.2015.3712] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Accepted: 02/06/2015] [Indexed: 11/05/2022] Open
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Suresh Babu S, Joladarashi D, Jeyabal P, Thandavarayan RA, Krishnamurthy P. RNA-stabilizing proteins as molecular targets in cardiovascular pathologies. Trends Cardiovasc Med 2015; 25:676-83. [PMID: 25801788 DOI: 10.1016/j.tcm.2015.02.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 01/31/2015] [Accepted: 02/13/2015] [Indexed: 01/08/2023]
Abstract
The stability of mRNA has emerged as a key step in the regulation of eukaryotic gene expression and function. RNA stabilizing proteins (RSPs) contain several RNA recognition motifs, and selectively bind to adenylate-uridylate-rich elements in the 3' untranslated region of several mRNAs leading to altered processing, stability, and translation. These post-transcriptional gene regulations play a critical role in cellular homeostasis; therefore act as molecular switch between 'normal cell' and 'disease state.' Many mRNA binding proteins have been discovered to date, which either stabilize (HuR/HuA, HuB, HuC, HuD) or destabilize (AUF1, tristetraprolin, KSRP) the target transcripts. Although the function of RSPs has been widely studied in cancer biology, its role in cardiovascular pathologies is only beginning to evolve. The current review provides an overall understanding of the potential role of RSPs, specifically HuR-mediated mRNA stability in myocardial infarction, hypertension and hypertrophy. Also, the effect of RSPs on various cellular processes including inflammation, fibrosis, angiogenesis, cell-death, and proliferation and its relevance to cardiovascular pathophysiological processes is presented. We also discuss the potential clinical implications of RSPs as therapeutic targets in cardiovascular diseases.
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Affiliation(s)
- Sahana Suresh Babu
- Department of Cardiovascular Sciences, Center for Cardiovascular Regeneration, Houston Methodist Research Institute, Houston, TX
| | - Darukeshwara Joladarashi
- Department of Cardiovascular Sciences, Center for Cardiovascular Regeneration, Houston Methodist Research Institute, Houston, TX
| | - Prince Jeyabal
- Department of Cardiovascular Sciences, Center for Cardiovascular Regeneration, Houston Methodist Research Institute, Houston, TX
| | - Rajarajan A Thandavarayan
- Department of Cardiovascular Sciences, Center for Cardiovascular Regeneration, Houston Methodist Research Institute, Houston, TX
| | - Prasanna Krishnamurthy
- Department of Cardiovascular Sciences, Center for Cardiovascular Regeneration, Houston Methodist Research Institute, Houston, TX.
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