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Di Vincenzo F, Yadid Y, Petito V, Emoli V, Masi L, Gerovska D, Araúzo-Bravo MJ, Gasbarrini A, Regenberg B, Scaldaferri F. Circular and Circulating DNA in Inflammatory Bowel Disease: From Pathogenesis to Potential Molecular Therapies. Cells 2023; 12:1953. [PMID: 37566032 PMCID: PMC10417561 DOI: 10.3390/cells12151953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 07/15/2023] [Accepted: 07/25/2023] [Indexed: 08/12/2023] Open
Abstract
Inflammatory bowel diseases (IBD), including Crohn's Disease (CD) and Ulcerative Colitis (UC) are chronic multifactorial disorders which affect the gastrointestinal tract with variable extent. Despite extensive research, their etiology and exact pathogenesis are still unknown. Cell-free DNAs (cfDNAs) are defined as any DNA fragments which are free from the origin cell and able to circulate into the bloodstream with or without microvescicles. CfDNAs are now being increasingly studied in different human diseases, like cancer or inflammatory diseases. However, to date it is unclear how IBD etiology is linked to cfDNAs in plasma. Extrachromosomal circular DNA (eccDNA) are non-plasmidic, nuclear, circular and closed DNA molecules found in all eukaryotes tested. CfDNAs appear to play an important role in autoimmune diseases, inflammatory processes, and cancer; recently, interest has also grown in IBD, and their role in the pathogenesis of IBD has been suggested. We now suggest that eccDNAs also play a role in IBD. In this review, we have comprehensively collected available knowledge in literature regarding cfDNA, eccDNA, and structures involving them such as neutrophil extracellular traps and exosomes, and their role in IBD. Finally, we focused on old and novel potential molecular therapies and drug delivery systems, such as nanoparticles, for IBD treatment.
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Affiliation(s)
- Federica Di Vincenzo
- IBD Unit, Centro di Malattie dell’Apparato Digerente (CeMAD), Medicina Interna e Gastroenterologia, Fondazione Policlinico Universitario “A. Gemelli” IRCCS, 00168 Rome, Italy; (F.D.V.); (L.M.); (A.G.); (F.S.)
- Dipartimento di Medicina e Chirurgia Traslazionale, Università Cattolica del Sacro Cuore, 00168 Rome, Italy; (Y.Y.); (V.E.)
| | - Ylenia Yadid
- Dipartimento di Medicina e Chirurgia Traslazionale, Università Cattolica del Sacro Cuore, 00168 Rome, Italy; (Y.Y.); (V.E.)
| | - Valentina Petito
- IBD Unit, Centro di Malattie dell’Apparato Digerente (CeMAD), Medicina Interna e Gastroenterologia, Fondazione Policlinico Universitario “A. Gemelli” IRCCS, 00168 Rome, Italy; (F.D.V.); (L.M.); (A.G.); (F.S.)
| | - Valeria Emoli
- Dipartimento di Medicina e Chirurgia Traslazionale, Università Cattolica del Sacro Cuore, 00168 Rome, Italy; (Y.Y.); (V.E.)
| | - Letizia Masi
- IBD Unit, Centro di Malattie dell’Apparato Digerente (CeMAD), Medicina Interna e Gastroenterologia, Fondazione Policlinico Universitario “A. Gemelli” IRCCS, 00168 Rome, Italy; (F.D.V.); (L.M.); (A.G.); (F.S.)
| | - Daniela Gerovska
- Computational Biology and Systems Biomedicine, Biodonostia Health Research Institute, Calle Doctor Begiristain s/n, 20014 San Sebastian, Spain; (D.G.); (M.J.A.-B.)
| | - Marcos Jesus Araúzo-Bravo
- Computational Biology and Systems Biomedicine, Biodonostia Health Research Institute, Calle Doctor Begiristain s/n, 20014 San Sebastian, Spain; (D.G.); (M.J.A.-B.)
- IKERBASQUE, Basque Foundation for Science, Calle María Díaz Harokoa 3, 48013 Bilbao, Spain
- Department of Cell Biology and Histology, Faculty of Medicine and Nursing, University of Basque Country (UPV/EHU), 48940 Leioa, Spain
| | - Antonio Gasbarrini
- IBD Unit, Centro di Malattie dell’Apparato Digerente (CeMAD), Medicina Interna e Gastroenterologia, Fondazione Policlinico Universitario “A. Gemelli” IRCCS, 00168 Rome, Italy; (F.D.V.); (L.M.); (A.G.); (F.S.)
- Dipartimento di Medicina e Chirurgia Traslazionale, Università Cattolica del Sacro Cuore, 00168 Rome, Italy; (Y.Y.); (V.E.)
| | - Birgitte Regenberg
- Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Universitetsparken 13, Room 426, DK-2100 Copenhagen, Denmark;
| | - Franco Scaldaferri
- IBD Unit, Centro di Malattie dell’Apparato Digerente (CeMAD), Medicina Interna e Gastroenterologia, Fondazione Policlinico Universitario “A. Gemelli” IRCCS, 00168 Rome, Italy; (F.D.V.); (L.M.); (A.G.); (F.S.)
- Dipartimento di Medicina e Chirurgia Traslazionale, Università Cattolica del Sacro Cuore, 00168 Rome, Italy; (Y.Y.); (V.E.)
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Tiwari RK, Moin A, Rizvi SMD, Shahid SMA, Bajpai P. Modulating neuroinflammation in neurodegeneration-related dementia: can microglial toll-like receptors pull the plug? Metab Brain Dis 2021; 36:829-847. [PMID: 33704660 DOI: 10.1007/s11011-021-00696-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 02/16/2021] [Indexed: 01/13/2023]
Abstract
Neurodegeneration-associated dementia disorders (NADDs), namely Alzheimer and Parkinson diseases, are developed by a significant portion of the elderly population globally. Extensive research has provided critical insights into the molecular basis of the pathological advancements of these diseases, but an efficient curative therapy seems elusive. A common attribute of NADDs is neuroinflammation due to a chronic inflammatory response within the central nervous system (CNS), which is primarily modulated by microglia. This response within the CNS is positively regulated by cytokines, chemokines, secondary messengers or cyclic nucleotides, and free radicals. Microglia mediated immune activation is regulated by a positive feedback loop in NADDs. The present review focuses on evaluating the crosstalk between inflammatory mediators and microglia, which aggravates both the clinical progression and extent of NADDs by forming a persistent chronic inflammatory milieu within the CNS. We also discuss the role of the human gut microbiota and its effect on NADDs as well as the suitability of targeting toll-like receptors for an immunotherapeutic intervention targeting the deflation of an inflamed milieu within the CNS.
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Affiliation(s)
- Rohit Kumar Tiwari
- Department of Biosciences, Integral University, Kursi Road, Lucknow, Uttar Pradesh, 226026, India
| | - Afrasim Moin
- Department of Pharmaceutics, College of Pharmacy, University of Hail, Hail, Kingdom of Saudi Arabia
| | - Syed Mohd Danish Rizvi
- Department of Pharmaceutics, College of Pharmacy, University of Hail, Hail, Kingdom of Saudi Arabia
| | - Syed Monowar Alam Shahid
- Department of Biochemistry, College of Medicine, University of Hail, Hail, Kingdom of Saudi Arabia
| | - Preeti Bajpai
- Department of Zoology, School of Life Sciences, Mahatma Gandhi Central University, Motihari, Bihar, 845401, India.
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3
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Sipos F, Kiss AL, Constantinovits M, Tulassay Z, Műzes G. Modified Genomic Self-DNA Influences In Vitro Survival of HT29 Tumor Cells via TLR9- and Autophagy Signaling. Pathol Oncol Res 2019; 25:1505-1517. [PMID: 30465163 DOI: 10.1007/s12253-018-0544-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Accepted: 11/16/2018] [Indexed: 02/08/2023]
Abstract
In relation of immunobiology, the consequence of the crosstalk between TLR9-signaling and autophagy is poorly documented in HT29 cancer cells. To assess the TLR9-mediated biologic effects of modified self-DNA sequences on cell kinetics and autophagy response HT29 cells were incubated separately with intact genomic (g), hypermethylated (m), fragmented (f), and hypermethylated/fragmented (m/f) self-DNAs. Cell viability, apoptosis, cell proliferation, colonosphere-formation were determined. Moreover, the relation of TLR9-signaling to autophagy response was assayed by real-time RT-PCR, immunocytochemistry and transmission electron microscopy (TEM). After incubation with g-, m-, and m/f-DNAs cell viability and proliferation decreased, while apoptosis increased. F-DNA treatment resulted in an increase of cell survival. Methylation of self-DNA resulted in decrease of TLR9 expression, while it did not influence the positive effect of DNA fragmentation on MyD88 and TRAF6 overexpression, and TNFα downregulation. Fragmentation of DNA abrogated the positive effect of methylation on IRAK2, NFκB and IL-8 mRNA upregulations. In case of the autophagy genes and proteins, g- and f-DNAs caused significant upregulation of Beclin1, Atg16L1, and LC3B. According to TEM analyses, autophagy was present in each group of tumor cells, but to a varying degree. Incubation with m-DNA suppressed tumor cell survival by inducing features of apoptotic cell death, and activated mitophagy. F-DNA treatment enhanced cell survival, and activated macroautophagy and lipophagy. Colonospheres were only present after m-DNA incubation. Our data provided evidence for a close existing interplay between TLR9-signaling and the autophagy response with remarkable influences on cell survival in HT29 cells subjected to modified self-DNA treatments.
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Affiliation(s)
- Ferenc Sipos
- 2nd Department of Internal Medicine, Semmelweis University, Szentkirályi street 46, Budapest, 1088, Hungary.
| | - Anna L Kiss
- Department of Human Morphology and Developmental Biology, Semmelweis University, Budapest, 1094, Hungary
| | - Miklós Constantinovits
- 2nd Department of Internal Medicine, Semmelweis University, Szentkirályi street 46, Budapest, 1088, Hungary
| | - Zsolt Tulassay
- 2nd Department of Internal Medicine, Semmelweis University, Szentkirályi street 46, Budapest, 1088, Hungary
- Molecular Medicine Research Unit, Hungarian Academy of Sciences, Budapest, 1051, Hungary
| | - Györgyi Műzes
- 2nd Department of Internal Medicine, Semmelweis University, Szentkirályi street 46, Budapest, 1088, Hungary
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Holm KL, Indrevaer RL, Myklebust JH, Kolstad A, Moskaug JØ, Naderi EH, Blomhoff HK. Myeloid cell leukaemia 1 has a vital role in retinoic acid-mediated protection of Toll-like receptor 9-stimulated B cells from spontaneous and DNA damage-induced apoptosis. Immunology 2016; 149:62-73. [PMID: 27278254 DOI: 10.1111/imm.12629] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 05/20/2016] [Accepted: 05/21/2016] [Indexed: 12/14/2022] Open
Abstract
Vitamin A is an essential anti-infective agent with pleiotropic effects on cells of the immune system. The goal of the present study was to unravel the impact of the vitamin A metabolite retinoic acid (RA) on B-cell survival related both to normal B-cell homeostasis and to the detrimental effects imposed by DNA-damaging agents. By combining RA with Toll-like receptor 9 (TLR9) ligands, we show that RA prevents spontaneous, irradiation- and doxorubicin-induced apoptosis of human B cells in an RA receptor-dependent manner. RA-mediated survival involved up-regulation of the anti-apoptotic protein myeloid cell leukemia 1 (MCL1) at the transcriptional level, and knock down of MCL1 by small interfering RNA partially reversed the effects of RA. To ensure that the combination of TLR9-ligands and RA would not promote the survival of malignant B cells, the combined effects of stimulation with RA and TLR9 ligands was assessed on cells from patients with B-cell malignancies. In contrast to the effects on normal B cells, the combination of TLR9 stimulation and RA neither enhanced the MCL1 levels nor inhibited the death of malignant B cells challenged by DNA-damaging agents. Taken together, the present results reveal a vital role of MCL1 in RA-mediated survival of normal B cells. Moreover, the findings suggest that RA in combination with TLR9 ligands might be useful adjuvants in the treatment of B-cell malignancies by selectively protecting normal and not malignant B cells from DNA-damage-induced cell death.
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Affiliation(s)
- Kristine L Holm
- Department of Molecular Medicine, Institute of Basic Medical Science, University of Oslo, Oslo, Norway
| | - Randi L Indrevaer
- Department of Molecular Medicine, Institute of Basic Medical Science, University of Oslo, Oslo, Norway
| | - June Helen Myklebust
- Department of Immunology, Institute for Cancer Research, Oslo University Hospital HF, Montebello, Oslo, Norway
| | - Arne Kolstad
- Department of Oncology, Division of Cancer Medicine, Surgery and Transplantation, Oslo University Hospital HF, Montebello, Oslo, Norway
| | - Jan Øivind Moskaug
- Department of Molecular Medicine, Institute of Basic Medical Science, University of Oslo, Oslo, Norway
| | - Elin H Naderi
- Department of Molecular Medicine, Institute of Basic Medical Science, University of Oslo, Oslo, Norway
| | - Heidi K Blomhoff
- Department of Molecular Medicine, Institute of Basic Medical Science, University of Oslo, Oslo, Norway
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5
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Su F, Bai F, Zhou H, Zhang Z. Reprint of: Microglial toll-like receptors and Alzheimer's disease. Brain Behav Immun 2016; 55:166-178. [PMID: 27255539 DOI: 10.1016/j.bbi.2016.05.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Revised: 10/09/2015] [Accepted: 10/15/2015] [Indexed: 01/04/2023] Open
Abstract
Microglial activation represents an important pathological hallmark of Alzheimer's disease (AD), and emerging data highlight the involvement of microglial toll-like receptors (TLRs) in the course of AD. TLRs have been observed to exert both beneficial and detrimental effects on AD-related pathologies, and transgenic animal models have provided direct and credible evidence for an association between TLRs and AD. Moreover, analyses of genetic polymorphisms have suggested interactions between genetic polymorphisms in TLRs and AD risk, further supporting the hypothesis that TLRs are involved in AD. In this review, we summarize the key evidence in this field. Future studies should focus on exploring the mechanisms underlying the potential roles of TLRs in AD.
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Affiliation(s)
- Fan Su
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu 210009, China
| | - Feng Bai
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu 210009, China.
| | - Hong Zhou
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu 210009, China
| | - Zhijun Zhang
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu 210009, China
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6
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Su F, Bai F, Zhou H, Zhang Z. Microglial toll-like receptors and Alzheimer's disease. Brain Behav Immun 2016; 52:187-198. [PMID: 26526648 DOI: 10.1016/j.bbi.2015.10.010] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Revised: 10/09/2015] [Accepted: 10/15/2015] [Indexed: 02/08/2023] Open
Abstract
Microglial activation represents an important pathological hallmark of Alzheimer's disease (AD), and emerging data highlight the involvement of microglial toll-like receptors (TLRs) in the course of AD. TLRs have been observed to exert both beneficial and detrimental effects on AD-related pathologies, and transgenic animal models have provided direct and credible evidence for an association between TLRs and AD. Moreover, analyses of genetic polymorphisms have suggested interactions between genetic polymorphisms in TLRs and AD risk, further supporting the hypothesis that TLRs are involved in AD. In this review, we summarize the key evidence in this field. Future studies should focus on exploring the mechanisms underlying the potential roles of TLRs in AD.
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Affiliation(s)
- Fan Su
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu 210009, China.
| | - Feng Bai
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu 210009, China.
| | - Hong Zhou
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu 210009, China.
| | - Zhijun Zhang
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu 210009, China.
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7
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Wu JY, Kuo CC. ADP-Ribosylation Factor 3 Mediates Cytidine-Phosphate-Guanosine Oligodeoxynucleotide-Induced Responses by Regulating Toll-Like Receptor 9 Trafficking. J Innate Immun 2015; 7:623-36. [PMID: 26067373 DOI: 10.1159/000430785] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 04/17/2015] [Indexed: 11/19/2022] Open
Abstract
Toll-like receptor 9 (TLR9) trafficking from the endoplasmic reticulum (ER) into endolysosomes is critical for eliciting cytidine-phosphate-guanosine (CpG) DNA-mediated immune responses. ADP-ribosylation factor 3 (ARF3) is a member of the Ras superfamily, which is crucial for a wide variety of cellular events including protein trafficking. In this study, we found that the inhibition of ARF3 by dominant mutants and siRNA impaired CpG oligodeoxynucleotide (ODN)-mediated responses whereas cells expressing the constitutively active ARF3 mutant enhanced CpG ODN-induced NF-x03BA;B activation and cytokine production. Further experiments with MyD88-overexpressing fibroblast cells transfected with a dominant-negative mutant and a constitutively active mutant of ARF3 demonstrated that ARF3 regulated CpG ODN-mediated signaling upstream of MyD88. Additional studies have shown that ARF3 inhibition impairs TLR9 trafficking from the ER into endolysosomes, thereby inhibiting the functional cleavage of TLR9, although it has no significant effect on CpG ODN uptake. Furthermore, activated ARF3 is associated with Unc93B1 and TLR9, suggesting that ARF3 conducts TLR9 trafficking by forming the TLR9-Unc93B1-ARF3 complex. Overall, our findings demonstrate that a novel ARF3 axis pathway mediates CpG ODN-induced responses by regulating TLR9 trafficking.
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Affiliation(s)
- Jing-Yiing Wu
- Institute of Cellular and System Medicine, National Health Research Institutes, Zhunan, Taiwan, ROC
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8
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Hiramatsu Y, Satho T, Hyakutake M, Irie K, Mishima K, Miake F, Kashige N. The anti-inflammatory effects of a high-frequency oligodeoxynucleotide from the genomic DNA of Lactobacillus casei. Int Immunopharmacol 2014; 23:139-47. [PMID: 25193776 DOI: 10.1016/j.intimp.2014.08.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 08/08/2014] [Accepted: 08/13/2014] [Indexed: 12/16/2022]
Abstract
Genomic DNA has been identified as an anti-inflammatory component of Lactobacillus species, the effects of which are mediated through toll-like receptor (TLR) 9. In this study, we identified 14 novel anti-inflammatory oligodeoxynucleotide (ODN) from the genomic DNA of Lactobacillus casei by measuring their effects on the secretion of interleukin (IL)-8 (CXCL8) in the human epithelial colorectal adenocarcinoma cell line Caco-2 cells. The ODN TTTTGCCG strongly decreased IL-8 secretion. In the genomic DNA of Lactobacillus species, the frequency of TTTTGCCG was highest in the genomic DNA of L. casei and similar among strains of L. casei. Decreases in inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 expressions in macrophage-like differentiated THP-1 cells confirmed the anti-inflammatory effect of TTTTGCCG. Furthermore, oral administration of TTTTGCCG ameliorated dextran sodium sulfate (DSS)-induced murine colitis and DSS-induced increased expression of inflammatory factor mRNAs, such as macrophage inflammatory protein (MIP)-2 (CXCL2), iNOS, and COX-2. The anti-inflammatory effect of TTTTGCCG was mainly regulated by an increase in heat shock protein (Hsp) 70 expression in the epithelium. TLR9 and Hsp90 may primarily mediate the anti-inflammatory effect of TTTTGCCG on Hsp70 signaling.
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Affiliation(s)
- Yukihiro Hiramatsu
- Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1, Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Tomomitsu Satho
- Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1, Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan.
| | - Mika Hyakutake
- Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1, Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Keiichi Irie
- Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1, Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Kenichi Mishima
- Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1, Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Fumio Miake
- Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1, Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Nobuhiro Kashige
- Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1, Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
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Wu HM, Zhang LF, Ding PS, Liu YJ, Wu X, Zhou JN. Microglial activation mediates host neuronal survival induced by neural stem cells. J Cell Mol Med 2014; 18:1300-12. [PMID: 24725889 PMCID: PMC4124015 DOI: 10.1111/jcmm.12281] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 02/12/2014] [Indexed: 12/19/2022] Open
Abstract
The rational of neural stem cells (NSCs) in the therapy of neurological disease is either to replace dead neurons or to improve host neuronal survival, the latter of which has got less attention and the underlying mechanism is as yet little known. Using a transwell co-culture system, we reported that, in organotypic brain slice cultures, NSCs significantly improved host neuronal viability. Interestingly, this beneficial effect of NSCs was abrogated by a microglial inhibitor minocycline, while it was mimicked by a microglial agonist, Toll-like receptor 9 (TLR9) ligand CpG-ODN, which supports the pro-vital mediation by microglia on this NSCs-improved neuronal survival. Moreover, we showed that NSCs significantly induced host microglial movement and higher expression of a microglial marker IBA-1, the latter of which was positively correlated with TLR9 or extracellular-regulated protein kinases 1/2 (ERK1/2) activation. Real-time PCR revealed that NSCs inhibited the expression of pro-inflammatory molecules, but significantly increased the expression of molecules associated with a neuroprotective phenotype such as CX3CR1, triggering receptor expressed on myeloid cells-2 (TREM2) and insulin growth factor 1 (IGF-1). Similarly, in the microglia cells, NSCs induced the same microglial response as that in the slices. Further treatment with TLR9 ligand CpG-ODN, TLR9 inhibitor chloroquine (CQ) or ERK1/2 inhibitor U0126 demonstrated that TLR9-ERK1/2 pathway was involved in the NSCs-induced microglial activation. Collectively, this study indicated that NSCs improve host neuronal survival by switching microglia from a detrimental to a neuroprotective phenotype in adult mouse brain, and the microglial TLR9-ERK1/2 pathway seems to participate in this NSCs-mediated rescue action.
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Affiliation(s)
- Hui-Mei Wu
- CAS Key Laboratory of Brain Function and Diseases, School of Life Science, University of Science and Technology of China, Hefei, Anhui, China; Anhui Geriatric Institute, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China
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10
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Yang B, Hosgood SA, Da Z, Harper SJF, Waller HL, Kay MD, Furness PN, Nicholson ML. Biomarkers assessing warm ischemic injury using an isolated porcine kidney hemoreperfusion model. Exp Biol Med (Maywood) 2013; 237:1462-73. [PMID: 23354405 DOI: 10.1258/ebm.2012.012050] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Prolonged warm ischemia (WI) occurring in marginal kidney donors together with reperfusion injury determines allograft survival, in which apoptosis and inflammation play crucial roles. There is no single valid biomarker, so far, to assess the degree of kidney donor injury. To define new biomarkers for detecting initial donor ischemic injury, caspase-3, caspase-7, apoptosis, inflammation, HSP70 and renal histological changes were examined in porcine kidneys subjected to 7- 15- 25- or 40-min WI, two-hour cold storage and six-hour hemoreperfusion. Caspase-3 activity was gradually increased by prolonged reperfusion, with a decrease trend against WI time. This result was verified by raised 17 kDa active caspase-3 in postreperfusion kidneys, with elevated 12 kDa active caspase-3 and lowered precursor at seven-minute WI. Active caspase-7 was also doubled by reperfusion with decreased precursor at seven-minute WI, but declined against prolonged WI. Apoptotic cells in tubular and interstitial areas were greatly increased by reperfusion at seven-minute WI, but decreased against prolonged WI. In addition, myeloperoxidase (MPO)+ cells were dramatically increased by reperfusion and presented as a bell-shape against WI time, while HSP70 was significantly increased at 7-min WI, but decreased at 40-min WI after reperfusion. In postreperfusion kidneys, tubular dilation and cell shedding were observed at 7- and 15-min WI, while tubular vacuolation and cell debris were found in tubular lumens at longer WI times. At 40-min WI, early nuclear pyknosis, tubular epithelia detachment and peri-tubular capillary dilation were detected. Furthermore, caspase-3, caspase-7, apoptosis, but not MPO+ cells or HSP70, were correlated with renal function. In conclusion, caspase-3, caspase-7 and apoptosis appear to be better biomarkers than MPO+ cells or HSP70 for assessing warm ischemic injury in donor kidneys. Hemoreperfusion activates caspase-3 and caspase-7, promotes apoptosis of damaged cells in kidneys only with limited WI, which might be beneficial to renal structural re-modeling and functional recovery.
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Affiliation(s)
- Bin Yang
- Transplant Surgery Group, Department of Infection, Immunity and Inflammation, University of Leicester, Leicester General Hospital, Leicester LE5 4PW, UK.
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Hancz A, Koncz G, Szili D, Sármay G. TLR9-mediated signals rescue B-cells from Fas-induced apoptosis via inactivation of caspases. Immunol Lett 2012; 143:77-84. [PMID: 22553782 DOI: 10.1016/j.imlet.2012.02.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The death receptor, CD95/Fas, serves to eliminate potentially dangerous, self-reactive B cells. Engagement of B-cell receptors (BCR) on mature B-cells mediates the escape from cell death resulting in the activation and expansion of antigen specific clones. In addition to the antigen receptors, the receptors of B-cell activating factor belong to the tumor necrosis factor (TNF) family (BAFFR); moreover, the pattern recognition receptor, TLR9 may also deliver survival signals inhibiting Fas-mediated death of B-cells. Our aim was to compare the mechanism of BCR-induced and the BAFFR- or TLR9-stimulated rescue of B-cells from CD95/Fas-mediated apoptosis. We have found that BAFFR and TLR9 collaborate with BCR to protect B-cells from Fas-induced elimination and the rescue is independent of protein synthesis. The results revealed that the TLR9- and BCR-triggered rescue signals are transmitted through partially overlapping pathways; the protein kinase C (PKC) and the abl kinase induced phosphorylation may inactivate caspases in both CpG and anti-IgG stimulated cells. However, PI3-K activation is crucial upon the BCR driven anti-apoptotic effect, while p38 MAPK-mediated inactivation of caspases seems to play essential role in TLR9-mediated protection against Fas-induced programmed cell death.
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Affiliation(s)
- Anikó Hancz
- Department of Immunology, Eötvös Loránd University, Budapest, Hungary
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12
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Campylobacter jejuni disrupts protective Toll-like receptor 9 signaling in colonic epithelial cells and increases the severity of dextran sulfate sodium-induced colitis in mice. Infect Immun 2012. [PMID: 22311925 DOI: 10.1128/iai.06066-] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Inflammatory bowel disease (IBD) is characterized by chronic intestinal inflammation associated with a dysregulated immune response to commensal bacteria in susceptible individuals. The relapse of IBD may occur following an infection with Campylobacter jejuni. Apical epithelial Toll-like receptor 9 (TLR9) activation by bacterial DNA is reported to maintain colonic homeostasis. We investigated whether a prior C. jejuni infection disrupts epithelial TLR9 signaling and increases the severity of disease in a model of mild dextran sulfate sodium (DSS) colitis in mice. In a further attempt to identify mechanisms, T84 monolayers were treated with C. jejuni followed by a TLR9 agonist. Transepithelial resistance (TER) and dextran flux across confluent monolayers were monitored. Immunohistochemistry, Western blotting, and flow cytometry were used to examine TLR9 expression. Mice colonized by C. jejuni lacked any detectable pathology; however, in response to low levels of DSS, mice previously exposed to C. jejuni exhibited significantly reduced weight gain and increased occult blood and histological damage scores. Infected mice treated with DSS also demonstrated a significant reduction in levels of the anti-inflammatory cytokine interleukin-25. In vitro studies indicated that apical application of a TLR9 agonist enhances intestinal epithelial barrier function and that this response is lost in C. jejuni-infected monolayers. Furthermore, infected cells secreted significantly more CXCL8 following the basolateral application of a TLR9 agonist. Surface TLR9 expression was reduced in C. jejuni-infected monolayers subsequently exposed to a TLR9 agonist. In conclusion, infection by C. jejuni disrupts TLR9-induced reinforcement of the intestinal epithelial barrier, and colonization by C. jejuni increases the severity of mild DSS colitis.
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Campylobacter jejuni disrupts protective Toll-like receptor 9 signaling in colonic epithelial cells and increases the severity of dextran sulfate sodium-induced colitis in mice. Infect Immun 2012; 80:1563-71. [PMID: 22311925 DOI: 10.1128/iai.06066-11] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Inflammatory bowel disease (IBD) is characterized by chronic intestinal inflammation associated with a dysregulated immune response to commensal bacteria in susceptible individuals. The relapse of IBD may occur following an infection with Campylobacter jejuni. Apical epithelial Toll-like receptor 9 (TLR9) activation by bacterial DNA is reported to maintain colonic homeostasis. We investigated whether a prior C. jejuni infection disrupts epithelial TLR9 signaling and increases the severity of disease in a model of mild dextran sulfate sodium (DSS) colitis in mice. In a further attempt to identify mechanisms, T84 monolayers were treated with C. jejuni followed by a TLR9 agonist. Transepithelial resistance (TER) and dextran flux across confluent monolayers were monitored. Immunohistochemistry, Western blotting, and flow cytometry were used to examine TLR9 expression. Mice colonized by C. jejuni lacked any detectable pathology; however, in response to low levels of DSS, mice previously exposed to C. jejuni exhibited significantly reduced weight gain and increased occult blood and histological damage scores. Infected mice treated with DSS also demonstrated a significant reduction in levels of the anti-inflammatory cytokine interleukin-25. In vitro studies indicated that apical application of a TLR9 agonist enhances intestinal epithelial barrier function and that this response is lost in C. jejuni-infected monolayers. Furthermore, infected cells secreted significantly more CXCL8 following the basolateral application of a TLR9 agonist. Surface TLR9 expression was reduced in C. jejuni-infected monolayers subsequently exposed to a TLR9 agonist. In conclusion, infection by C. jejuni disrupts TLR9-induced reinforcement of the intestinal epithelial barrier, and colonization by C. jejuni increases the severity of mild DSS colitis.
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Wu JY, Kuo CC. Pivotal role of ADP-ribosylation factor 6 in Toll-like receptor 9-mediated immune signaling. J Biol Chem 2011; 287:4323-34. [PMID: 22170068 DOI: 10.1074/jbc.m111.295113] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
CpG oligodeoxynucleotide (CpG ODN) cellular uptake into endosomes, the rate-limiting step of Toll-like receptor 9 (TLR9) signaling, is critical in eliciting innate immune responses. ADP-ribosylation factor 6 (ARF6) is a member of the Ras superfamily, which is critical to a wide variety of cellular events including endocytosis. Here, we found that inhibition of ARF6 by dominant mutants and siRNA impaired CpG ODN-mediated responses, whereas cells expressing the constitutively active ARF6 mutant enhanced CpG ODN-induced cytokine production. Inhibition of ARF6 impaired TLR9 trafficking into endolysosomes, thereby inhibiting proceed functional cleavage of TLR9. Additional studies showed that CpG ODN uptake was increased in ARF6-activated cells but impaired in ARF6-defective cells. Furthermore, cells pretreated with CpG ODN but not GpC ODN had increased CpG ODN uptake due to CpG ODN-induced ARF6 activity. Further studies with ARF6-defective and ARF6-activated cells demonstrated that class III phosphatidylinositol 3-kinases (PI3K) was required for downstream ARF6 regulation of CpG ODN uptake. Together, our findings demonstrate that a novel class III PI3K-ARF6 axis pathway mediates TLR9 signaling by regulating the cellular uptake of CpG ODN.
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Affiliation(s)
- Jing-Yiing Wu
- Institute of Cellular and System Medicine, National Health Research Institutes, Zhunan, Miaoli 35053, Taiwan
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Lim EJ, Park DW, Jeong TW, Chin BR, Bae YS, Baek SH. TRAIL is involved in CpG ODN-mediated anti-apoptotic signals. Oncol Rep 2011; 27:1213-8. [PMID: 22159760 PMCID: PMC3583470 DOI: 10.3892/or.2011.1579] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Accepted: 11/16/2011] [Indexed: 11/05/2022] Open
Abstract
Synthetic oligodeoxynucleotides (ODNs) with the CpG-motifs are recognized by toll-like receptor 9 (TLR9), which elicits an immune response. Serum starvation of Raw264.7 cells increased tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) expression. However, treatment with CpG ODN reduced TRAIL expression as well as apoptosis by serum starvation. In serum starved cells, TLR9 inhibitors recovered the decreasing TRAIL expression and sub-G1 accumulation by CpG ODN. CpG ODN-regulated anti-apoptotic signals which were dependent on the Akt-FoxO3a signaling pathway. CpG ODNs activated Akt and inactivated FoxO3a in serum starved cells. Knockdown of FoxO3a by siRNA decreased TRAIL expression and apoptosis in serum-starved cells. In contrast, FoxO3a overexpression increased apoptosis by serum starvation, and CpG ODNs blocked these effects through TRAIL expression. LY294002, a PI3K-Akt inhibitor, blocked the CpG ODN effect of TRAIL expression and the sub-G1 population in serum starved cells. In contrast, overexpression of wild-type Akt reduced additional sub-G1 cells both in non-CpG ODN- and CpG ODN-treated cells. Taken together, these results demonstrate the involvement of Akt-FoxO3a signaling in TLR9-mediated downregulation of TRAIL and anti-apoptotic signals.
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Affiliation(s)
- Eun-Jung Lim
- Department of Biochemistry and Molecular Biology, Aging-Associated Vascular Disease Research Center, College of Medicine, Yeungnam University, Daegu, Republic of Korea
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Saxena M, Busca A, Pandey S, Kryworuchko M, Kumar A. CpG protects human monocytic cells against HIV-Vpr-induced apoptosis by cellular inhibitor of apoptosis-2 through the calcium-activated JNK pathway in a TLR9-independent manner. THE JOURNAL OF IMMUNOLOGY 2011; 187:5865-78. [PMID: 22068233 DOI: 10.4049/jimmunol.1100115] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Monocytic cells survive HIV replication and consequent cytopathic effects because of their decreased sensitivity to HIV-induced apoptosis. However, the mechanism underlying this resistance to apoptosis remains poorly understood. Lymphocytic cells are exposed to microbial products because of their translocation from the gut in persons with chronic HIV infections or following coinfections. We hypothesized that activation of monocytic cells by such microbial products through interaction with corresponding TLRs may confer antiapoptotic signals. Using HIV-viral protein R (Vpr)(52-96) peptide as a model apoptosis-inducing agent, we demonstrated that unlike monocyte-derived macrophages, undifferentiated primary human monocytes and promonocytic THP-1 cells are highly susceptible to Vpr(52-96)-induced apoptosis. Interestingly, monocytes and THP-1 cells stimulated with TLR9 agonist CpG induced almost complete resistance to Vpr(52-96)-induced apoptosis, albeit through a TLR9-independent signaling pathway. Moreover, CpG selectively induced the antiapoptotic cellular inhibitor of apoptosis (c-IAP)-2 protein and inhibition of the c-IAP-2 gene by either specific small interfering RNA or synthetic second mitochondrial activator of caspases mimetic reversed CpG-induced resistance against Vpr(52-96)-mediated apoptosis. We demonstrated that c-IAP-2 is regulated by the JNK and calcium signaling pathway, in particular calmodulin-dependent protein kinase-II. Furthermore, inhibition of JNK and the calcium signaling including the calmodulin-dependent protein kinase-II by either pharmacological inhibitors or their specific small interfering RNAs reversed CpG-induced protection against Vpr(52-96)-mediated apoptosis. We also show that CpG induced JNK phosphorylation through activation of the calcium signaling pathway. Taken together, our results suggest that CpG-induced protection may be mediated by c-IAP-2 through the calcium-activated JNK pathway via what appeared to be TLR9-independent signaling pathways.
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Affiliation(s)
- Mansi Saxena
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada
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Yang B, Hosgood SA, Bagul A, Waller HL, Nicholson ML. Erythropoietin regulates apoptosis, inflammation and tissue remodelling via caspase-3 and IL-1β in isolated hemoperfused kidneys. Eur J Pharmacol 2011; 660:420-30. [DOI: 10.1016/j.ejphar.2011.03.044] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Revised: 03/07/2011] [Accepted: 03/28/2011] [Indexed: 10/18/2022]
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Kayama M, Nakazawa T, Thanos A, Morizane Y, Murakami Y, Theodoropoulou S, Abe T, Vavvas D, Miller JW. Heat shock protein 70 (HSP70) is critical for the photoreceptor stress response after retinal detachment via modulating anti-apoptotic Akt kinase. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 178:1080-91. [PMID: 21356360 DOI: 10.1016/j.ajpath.2010.11.072] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Revised: 10/25/2010] [Accepted: 11/09/2010] [Indexed: 02/08/2023]
Abstract
Photoreceptor apoptosis is a major cause of vision loss in many ocular diseases. Significant progress has been made to elucidate the molecular pathways involved in this process, yet little is known about proteins counteracting these apoptotic pathways. It is established that heat shock proteins (HSPs) function as molecular helper proteins (chaperones) by preventing protein aggregation and facilitating refolding of dysfunctional proteins, critical to the survival of all organisms. Here, we investigated the role of HSP70 on photoreceptor survival after experimental retinal detachment (RD) in mice and rats. We found that HSP70 was up-regulated after RD and associated with phosphorylated Akt, thereby preventing its dephosphorylation and further activation of cell death pathways. Administration of quercetin, which inhibits HSP70 and suppresses Akt phosphorylation significantly increased photoreceptor apoptosis. Similarly, RD-induced photoreceptor apoptosis was augmented in mice carrying hypomorphic mutations of the genes encoding HSP70. On the other hand, administration of geranylgeranylacetone, which induces an increase in HSP70 significantly decreased photoreceptor apoptosis after RD through prolonged activation of Akt pathway. Thus, HSP70 may be a favorable potential target to increase photoreceptor cell survival after RD.
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Affiliation(s)
- Maki Kayama
- Retina Service, Angiogenesis Laboratory, Massachusetts Eye and Ear Infirmary, and the Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02114, USA
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Lim EJ, Park DW, Lee JG, Lee CH, Bae YS, Hwang YC, Jeong JW, Chin BR, Baek SH. Toll-like receptor 9-mediated inhibition of apoptosis occurs through suppression of FoxO3a activity and induction of FLIP expression. Exp Mol Med 2011; 42:712-20. [PMID: 20739833 DOI: 10.3858/emm.2010.42.10.070] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Synthetic oligodeoxynucleotides (ODN) with a CpG-motif are recognized by Toll-like receptor 9 (TLR9) and pleiotropic immune responses are elicited. Stimulation of macrophages with TLR9 agonist prevented apoptosis induced by serum deprivation through increased expression of FLICE-like inhibitory protein (FLIP). CpG ODN-mediated anti-apoptosis depended on the TLR9-Akt-FoxO3a signaling pathway. Inhibition of TLR9 by small interfering (si) RNA or an inhibitor suppressed CpG ODN-mediated anti-apoptosis. Analysis of signaling pathways revealed that the anti-apoptotic effect of CpG ODN required phosphorylation of FoxO3a and its translocation from the nucleus to the cytosol. Overexpression of FoxO3a increased apoptosis induced by serum deprivation and CpG ODN blocked these effects through FLIP expression. In contrast, siRNA knock-down of FoxO3a decreased apoptosis by serum deprivation. In addition, Akt activation was involved in CpG ODN-induced phosphorylation of FoxO3a, expression of FLIP, and anti-apoptosis. Taken together, these results demonstrate the involvement of Akt-FoxO3a in TLR9-mediated anti-apoptosis and indicate that FoxO3a is a distinct regulator for FLIP expression.
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Affiliation(s)
- Eun-Jung Lim
- Aging-Associated Vascular Disease Research Center, Department of Biochemistry and Molecular Biology, College of Medicine, Yeungnam University, Daegu 705-802, Korea
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Leucocyte depletion improves renal function in porcine kidney hemoreperfusion through reduction of myeloperoxidase+ cells, caspase-3, IL-1β, and tubular apoptosis. J Surg Res 2010; 164:e315-24. [PMID: 20869081 DOI: 10.1016/j.jss.2010.07.044] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Revised: 06/17/2010] [Accepted: 07/12/2010] [Indexed: 11/21/2022]
Abstract
BACKGROUND Leucocytes play crucial roles in ischemia reperfusion injury that is inevitable in kidney transplantation. Leucocyte-depleted hemoreperfusion improved post-ischemic renal function was demonstrated in our previous study and its underlying mechanisms were further investigated in this study. METHODS Porcine kidneys were subjected to 7 min warm ischemia and 2 h cold storage, and preserved by hemoreperfusion with or without leucocyte depletion for 6 h on an isolated organ perfusion system. RESULTS Tubulointerstitial damage was improved by leucocyte depletion, which was accompanied by reduced myeloperoxidase+ cell infiltration up to 91%. Apoptotic cells in tubular and interstitial areas were increased by hemoreperfusion, but tubular apoptosis was decreased by leucocyte depletion. The raised caspase-3 activity by hemoreperfusion was almost completely abolished by leucocyte depletion. In addition, the expression of IL-1β active subunit was enhanced by hemoreperfusion, but partially reduced by leucocyte depletion, although IL-1β precursor and HSP70 were increased by hemoreperfusion regardless of leucocyte depletion. Furthermore, myeloperoxidase+ cells were associated with caspase-3 activity, both of which were positively correlated with tubular apoptosis, IL-1β active subunit, tubulointerstitial damage, and serum creatinine, while HSP70 was linked to renal blood flow. CONCLUSIONS Leucocyte depletion improved post-ischemic renal function and structure was mainly due to reduced infiltration of myeloperoxidase+ cells, which was associated with decreased apoptosis, caspase-3 activity and IL-1β activation.
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Ghadimi D, Vrese MD, Heller KJ, Schrezenmeir J. Effect of natural commensal-origin DNA on toll-like receptor 9 (TLR9) signaling cascade, chemokine IL-8 expression, and barrier integritiy of polarized intestinal epithelial cells. Inflamm Bowel Dis 2010; 16:410-27. [PMID: 19714766 DOI: 10.1002/ibd.21057] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND AIM The intestinal epithelium is constantly exposed to high levels of genetic material like bacterial DNA. Under normal physiological conditions, the intestinal epithelial monolayer as a formidable dynamic barrier with a high-polarity structure facilitates only a controlled and selective flux on components between the lumen and the underlining mucosa and even is able to facilitate structure-based macromolecules movement. The aim of this study was to test the effect of natural commensal-origin DNA on the TLR9 signaling cascade and the barrier integrity of polarized intestinal epithelial cells (IECs). METHODS : Polarized HT-29 and T84 cells were treated with TNF-alpha in the presence or absence of DNA from Lactobacillus rhamnosus GG (LGG) and Bifidobacterium longum. TLR9 and interleukin-8 (IL-8) mRNA expression was assessed by semiquantitative and TaqMan real-time reverse-transcription polymerase chain reaction. Expression of TLR9 protein, degradation of inhibitor of kappa B alpha (IkappaBalpha), and p38 mitogen-activated protein kinase (p38 MAP) phosphorylation were assessed by Western blotting. To further reveal the role of TLR9 signaling, the TLR9 gene was silenced by siRNA. IL-8 secretion was measured by an enzyme-linked immunosorbent assay. Nuclear factor-kappa B (NF-kappaB) activity was assessed by the electrophoretic mobility shift assay (EMSA) and NF-kappaB-dependent luciferase reporter gene assays. As an indicator of tight junction formation and monolayer integrity of epithelial cell monolayers, transepithelial electrical resistance (TER) was repetitively monitored. Transmonolayer movement of natural commensal-origin DNA across monolayers was monitored using qRT-PCR and nested PCR based on bacterial 16S rRNA genes. RESULTS In response to apically applied natural commensal-origin DNA, polarized HT-29 and T84 cells enhanced expression of TLR9 in a specific manner, which was subsequently associated with attenuation of TNF-alpha-induced NF-kappaB activation and NF-kappaB-mediated IL-8 expression. TLR9 silencing abolished this inhibitory effect. Apically applied LGG DNA attenuated TNF-alpha-enhanced NF-kappaB activity by reducing IkappaBalpha degradation and p38 phosphorylation. LGG DNA did not decrease the TER but rather diminished the TNF-alpha-induced TER reduction. Translocation of natural commensal-origin DNA into basolateral compartments did not occur under tested conditions. CONCLUSIONS Our study indicates that TLR9 signaling mediates, at least in part, the anti-inflammatory effects of natural commensal-origin DNA on the gut because TLR9 silencing abolished the inhibitory effect of natural commensal-origin DNA on TNF-alpha-induced IL-8 secretion in polarized IECs. The nature of the TLR9 agonist, the polarity of cells, and the tight junction integrity of IECs has to be taken into account in order to predict the outcome of TLR9 signaling. (Inflamm Bowel Dis 2010).
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Affiliation(s)
- Darab Ghadimi
- Department of Physiology and Biochemistry of Nutrition, Max Rubner-Institut, Kiel, Germany.
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CpG-ODNs induces up-regulated expression of chemokine CCL9 in mouse macrophages and microglia. Cell Immunol 2010; 260:113-8. [PMID: 19883904 DOI: 10.1016/j.cellimm.2009.10.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Revised: 10/01/2009] [Accepted: 10/06/2009] [Indexed: 11/24/2022]
Abstract
Unmethylated CpG oligodeoxynucleotides (CpG-ODNs) interact with Toll-like receptor (TLR) 9 to activate macrophage/microglia in central nervous system (CNS). Here, we investigated the potential involvement of the chemokine CCL9 and its receptor CCR1 in the effects of CpG-ODNs on macrophage/microglial cells. CpG-ODNs enhanced the expression of TLR9 mRNA of RAW264.7 macrophage and BV2 microglia cells time dependently. The expression of CCL9 of macrophages/microglia showed different responsiveness upon stimulation with a variety of CpG-ODN sequences. The CpG-ODNs-mediated induction of CCL9 was TLR9/MyD88 dependent and associated with activation of stress kinases, particularly ERK, p38 MAPK and PI3K. The expression of CCR1 was also significantly increased by CpG-ODNs that increased CCL9 expression. These results reveal the potential involvement of CCL9 and CCR1 in regulation of macrophage and microglial cells by CpG-ODNs and may help improving our understanding about the role of the chemokine/chemokine receptor pairs in macrophage/microglia under physiologic and pathologic conditions.
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Sugiura H, Yoshida T, Mitobe M, Yoshida S, Shiohira S, Nitta K, Tsuchiya K. Klotho reduces apoptosis in experimental ischaemic acute kidney injury via HSP-70. Nephrol Dial Transplant 2009; 25:60-8. [PMID: 19745103 DOI: 10.1093/ndt/gfp451] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND High Klotho expression has been detected in the kidney, and since the results of a recent study suggested that Klotho induction mitigates ischaemic damage in the kidney, in the present study we explored the mechanism by which Klotho expression reduces renal ischaemia-reperfusion injury (IRI). METHODS Male mice were subjected to bilateral renal ischaemia for 30 min and reperfusion for 24 h, or to a sham operation. Both the IRI group and the sham group were intravenously injected with an adenovirus harbouring the mouse Klotho gene (ad-kl) before renal IRI. In addition, mIMCD3 cells induced to overexpress Klotho by transferring the Klotho gene with ad-kl were analysed by DNA microarray and real-time PCR. Renal expression of Klotho and several genes selected by DNA microarray were assessed by real-time PCR or Western blotting, and TUNEL staining was performed to assess apoptosis. RESULTS Prior administration of ad-kl to the mice resulted in robust induction of Klotho mRNA in the kidney and liver. Ad-kl transfer improved the plasma creatinine values and mitigated the histological damage and apoptosis induced by IRI. Expression of several genes was altered in mIMCD3 cells as a result of the change in Klotho expression, and expression of heat shock protein 70 (HSP70), in particular, was up-regulated in ad-kl mouse kidneys and HK2 cells. CONCLUSION The results suggest that Klotho is involved in the pathophysiology of IRI. Klotho mitigates apoptosis in experimental ischaemic acute kidney injury via expression of HSP70.
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Affiliation(s)
- Hidekazu Sugiura
- Department of Medicine IV, Tokyo Women's Medical University, Tokyo, Japan
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Bekeredjian-Ding I, Doster A, Schiller M, Heyder P, Lorenz HM, Schraven B, Bommhardt U, Heeg K. TLR9-activating DNA up-regulates ZAP70 via sustained PKB induction in IgM+ B cells. THE JOURNAL OF IMMUNOLOGY 2009; 181:8267-77. [PMID: 19050243 DOI: 10.4049/jimmunol.181.12.8267] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
In the past, ZAP70 was considered a T cell-specific kinase, and its aberrant expression in B-CLL cells was interpreted as a sign of malignant transformation and dedifferentiation. It was only recently that ZAP70 was detected in normal human B cells. In this study, we show that TLR9-activated B cells resemble B-cell chronic lymphocytic leukemia cells with regard to CD5, CD23, CD25, and heat shock protein 90 expression. Furthermore, stimulatory CpG and GpC DNA oligonucleotides target CD27(+)IgM(+) and CD27(-)IgM(+) B cells (but not IgM(-) B cells) and enhance ZAP70 expression predominantly in the IgM(+)CD27(+) B cell subset. ZAP70 is induced via activation of TLR-7 or -9 in a MyD88-dependent manner, depends on protein kinase B (PKB)/mammalian target of rapamycin signaling and is rapamycin sensitive. Furthermore, ZAP70 expression levels correlate with induction of cyclin A2, prolonged B cell proliferation, and sustained induction of PKB. These events are not observed upon CD40 ligation. However, this deficit can be overcome by the expression of constitutively active PKB, given that CD40 ligation of PKB-transgenic B cells induces B cell proliferation and ZAP70 expression. These results highlight a major difference between CD40- and TLR-7/9-mediated B cell activation and suggest that ZAP70 expression levels in B cells give an estimate of the proliferative potential and the associated PKB availability.
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Affiliation(s)
- Isabelle Bekeredjian-Ding
- Department of Medical Microbiology and Hygiene, University Hospital Heidelberg, Heidelberg, Germany.
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TLR9 engagement on CD4 T lymphocytes represses gamma-radiation-induced apoptosis through activation of checkpoint kinase response elements. Blood 2007; 111:2704-13. [PMID: 18086870 DOI: 10.1182/blood-2007-07-104141] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
T cell-based therapies have much promise in cancer treatment. This approach may be enhanced if used in combination with radiotherapy provided that tumor-specific T cells can be protected against the effects of radiotherapy. Previously, we demonstrated that administration of TLR9 ligand into mice decreased activation- and serum deprivation-induced cell death in T cells. We hypothesized that TLR9 engagement on T lymphocytes decreased apoptosis after cellular stress. We show that TLR9 engagement on murine CD4 T cells reduces gamma-radiation-induced apoptosis as judged by decreased annexin-V/PI staining, caspase-3 activation, and PARP cleavage. TLR9-stimulated cells show heightened accumulation at the G2 cell-cycle phase and increased DNA repair rates. Irradiated, TLR9-engaged cells showed higher levels of phosphorylated Chk1 and Chk2. While the levels of activated ATM in response to IR did not differ between TLR9-stimulated and unstimulated cells, inhibition of ATM/ATR and Chk1/Chk2 kinases abolished the radioprotective effects in TLR9-stimulated cells. In vivo, TLR9-stimulated cells displayed higher radio resistance than TLR9-stimulated MyD88(-/-) T cells and responded to antigenic stimulation after total body irradiation. These findings show, for the first time, that TLR9 engagement on CD4 T cells reduces IR-induced apoptosis by influencing cell-cycle checkpoint activity, potentially allowing for combinatorial immunotherapy and radiotherapy.
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Jacobs AT, Marnett LJ. Heat Shock Factor 1 Attenuates 4-Hydroxynonenal-mediated Apoptosis. J Biol Chem 2007; 282:33412-33420. [PMID: 17873279 DOI: 10.1074/jbc.m706799200] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Lipid peroxidation is a consequence of both normal physiology and oxidative stress that generates various reactive metabolites, a principal end product being 4-hydroxynonenal (HNE). As a diffusible electrophile, HNE reacts extensively with cellular nucleophiles. Consequently, HNE alters cellular signaling and activates the intrinsic apoptotic cascade. We have previously demonstrated that in addition to promoting apoptosis, HNE activates stress response pathways, including the antioxidant, endoplasmic reticulum stress, DNA damage, and heat shock responses. Here we demonstrate that activation of the heat shock response by HNE is dependent on the expression and nuclear translocation of heat shock factor 1 (HSF1), which promotes the expression of heat shock protein 40 (Hsp40) and Hsp70-1. Ectopic expression and immunoprecipitation of c-Myc-tagged Hsp70-1 indicates that HNE disrupts the inhibitory interaction between Hsp70-1 and HSF1, leading to the activation heat shock gene expression. Using siRNA to silence HSF1 expression, we observe that HSF1 is necessary for the induction of Hsp40 and Hsp70-1 by HNE, and the lack of Hsp expression is correlated with an increase in apoptosis. Nrf2, the transcription factor that mediates the antioxidant response, was also silenced using siRNA. Silencing Nrf2 also enhanced the cytotoxicity of HNE, but not as effectively as HSF1. Silencing HSF1 expression facilitates the activation of JNK pro-apoptotic signaling and selectively decreases expression of the anti-apoptotic Bcl-2 family member Bcl-X(L). Overexpression of Bcl-X(L) attenuates HNE-mediated apoptosis in HSF1-silenced cells. Overall, activation of HSF1 and stabilization of Bcl-X(L) mediate a protective response that may contribute significantly to the cellular biology of lipid peroxidation.
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Affiliation(s)
- Aaron T Jacobs
- Department of Biochemistry, Vanderbilt Institute of Chemical Biology, Center in Molecular Toxicology, and Vanderbilt-Ingram Comprehensive Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| | - Lawrence J Marnett
- Department of Biochemistry, Vanderbilt Institute of Chemical Biology, Center in Molecular Toxicology, and Vanderbilt-Ingram Comprehensive Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146.
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Koido S, Hara E, Homma S, Mitsunaga M, Takahara A, Nagasaki E, Kawahara H, Watanabe M, Toyama Y, Yanagisawa S, Kobayashi S, Yanaga K, Fujise K, Gong J, Tajiri H. Synergistic Induction of Antigen-Specific CTL by Fusions of TLR-Stimulated Dendritic Cells and Heat-Stressed Tumor Cells. THE JOURNAL OF IMMUNOLOGY 2007; 179:4874-83. [PMID: 17878387 DOI: 10.4049/jimmunol.179.7.4874] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Dendritic cell (DC)/tumor cell fusion cells (FCs) can induce potent CTL responses. The therapeutic efficacy of a vaccine requires the improved immunogenicity of both DCs and tumor cells. The DCs stimulated with the TLR agonist penicillin-killed Streptococcus pyogenes (OK-432; OK-DCs) showed higher expression levels of MHC class I and II, CD80, CD86, CD83, IL-12, and heat shock proteins (HSPs) than did immature DCs. Moreover, heat-treated autologous tumor cells displayed a characteristic phenotype with increased expression of HSPs, carcinoembryonic Ag (CEA), MUC1, and MHC class I (HLA-A2 and/or A24). In this study, we have created four types of FC preparation by alternating fusion cell partners: 1) immature DCs fused with unheated tumor cells; 2) immature DCs fused with heat-treated tumor cells; 3) OK-DCs fused with unheated tumor cells; and 4) OK-DCs fused with heat-treated tumor cells. Although OK-DCs fused with unheated tumor cells efficiently enhanced CTL induction, OK-DCs fused with heat-treated tumor cells were most active, as demonstrated by: 1) up-regulation of multiple HSPs, MHC class I and II, CEA, CD80, CD86, CD83, and IL-12; 2) activation of CD4+ and CD8+ T cells able to produce IFN- gamma at higher levels; 3) efficient induction of CTL activity specific for CEA or MUC1 or both against autologous tumor; and 4) superior abilities to induce CD107+ IFN-gamma+ CD8+ T cells and CD154+ IFN-gamma+ CD4+ T cells. These results strongly suggest that synergism between OK-DCs and heat-treated tumor cells enhances the immunogenicity of FCs and provides a promising means of inducing therapeutic antitumor immunity.
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Affiliation(s)
- Shigeo Koido
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan.
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28
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Nagarajan G, Kuo CC, Liang CM, Chen CM, Liang SM. Effects of CpG-B ODN on the protein expression profile of swine PBMC. Vet Res 2007; 38:795-808. [PMID: 17727805 DOI: 10.1051/vetres:2007032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Accepted: 04/26/2007] [Indexed: 11/14/2022] Open
Abstract
The CpG motif within bacterial DNA is a potent immuno-stimulatory moiety. Here, using a 2-D electrophoretic approach, we investigated the effect of synthetic oligodeoxynucleotide containing a B type CpG motif (CpG-B ODN) on the protein expression profile of swine peripheral blood mononuclear cells (PBMC). We found that several proteins including spondin 1, N-acetolactate alpha linked acidic dipeptidase; V kappa light chain, T cell receptor variable alpha chain, heat shock protein (Hsp) 60, Hsp70, KIAA0857 protein, and PNAS-146 were up-regulated in PBMC by CpG-B ODN stimulation. Further studies showed that CpG-B ODN-mediated Hsp60, Hsp70 and Hsp90 expressions were closely associated with the TLR9 signalling pathway. Pretreatment with inhibitors of Hsp70, Hsp90 and TLR9 all blocked the CpG-B ODN-mediated anti-apoptotic effect in swine PBMC. These results suggest that CpG-B ODN treatment of swine PBMC may enhance the expression of biologically active proteins, notably spondin 1, V kappa light chain, T cell receptor variable alpha chain and Hsps, which may play an important role in CpG-B ODN-mediated activation of immune responses and enhancement of swine PBMC survival.
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Affiliation(s)
- Govindarajulu Nagarajan
- Agricultural Biotechnology Research Center, Academia Sinica, No 128, Academia Road, Sec 2, 11529, Taipei, Taiwan
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29
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Kuo CC, Liang CM, Lai CY, Liang SM. Involvement of heat shock protein (Hsp)90 beta but not Hsp90 alpha in antiapoptotic effect of CpG-B oligodeoxynucleotide. THE JOURNAL OF IMMUNOLOGY 2007; 178:6100-8. [PMID: 17475835 DOI: 10.4049/jimmunol.178.10.6100] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Unmethylated CpG oligodeoxynucleotides (CpG ODNs) activate immune responses in a TLR9-dependent manner. In this study, we found that stimulation of mouse macrophages and dendritic cells with B-type CpG ODN (CpG-B ODN) increased the cellular level of heat shock protein (Hsp) 90beta but not Hsp90alpha and prevented apoptosis induced by serum starvation or staurosporine treatment. The CpG-B ODN-induced Hsp90beta expression depended on TLR9, MyD88, and PI3K. Inhibition of Hsp90beta level by expressing small-interfering RNA suppressed not only Hsp90beta expression but also PI3K-dependent phosphorylation of Akt and CpG-B ODN-mediated antiapoptosis. Additional studies demonstrated that as described by other group in mast cells, Hsp90beta but not Hsp90alpha was associated with Bcl-2. Inhibition of Hsp90beta suppressed the CpG-B ODN-induced association of Hsp90beta with Bcl-2 and impaired the inhibitory effect of CpG-B ODN in the release of cytochrome c and activation of caspase-3. This study thus reveals the involvement of Hsp90beta but not Hsp90alpha in CpG-B ODN-mediated antiapoptotic response and that Hsp90beta is distinct from Hsp90alpha in regulation of the cellular function of immune cells.
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Affiliation(s)
- Cheng-Chin Kuo
- Agricultural Biotechnology Research Center, Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
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