29 results on '"Eli-Berchoer L"'
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2. sj-docx-1-jdr-10.1177_00220345211042830 ��� Supplemental material for ���� T Cells Differentially Regulate Bone Loss in Periodontitis Models
- Author
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Barel, O., Aizenbud, Y., Tabib, Y., Jaber, Y., Leibovich, A., Horev, Y., Zubeidat, K., Saba, Y., Eli-Berchoer, L., Heyman, O., Wilensky, A., Prinz, I., and Hovav, A.H.
- Subjects
110599 Dentistry not elsewhere classified ,FOS: Materials engineering ,FOS: Clinical medicine ,91299 Materials Engineering not elsewhere classified - Abstract
Supplemental material, sj-docx-1-jdr-10.1177_00220345211042830 for ���� T Cells Differentially Regulate Bone Loss in Periodontitis Models by O. Barel, Y. Aizenbud, Y. Tabib, Y. Jaber, A. Leibovich, Y. Horev, K. Zubeidat, Y. Saba, L. Eli-Berchoer, O. Heyman, A. Wilensky, I. Prinz and A.H. Hovav in Journal of Dental Research
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- 2021
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3. γδ T Cells Differentially Regulate Bone Loss in Periodontitis Models.
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Barel, O., Aizenbud, Y., Tabib, Y., Jaber, Y., Leibovich, A., Horev, Y., Zubeidat, K., Saba, Y., Eli-Berchoer, L., Heyman, O., Wilensky, A., Prinz, I., and Hovav, A.H.
- Abstract
γδ T cells are nonclassical T lymphocytes representing the major T-cell population at epithelial barriers. In the gingiva, γδ T cells are enriched in epithelial regions adjacent to the biofilm and are considered to regulate local immunity to maintain host-biofilm homeostatic interactions. This delicate balance is often disrupted resulting in the development of periodontitis. Previous studies in mice lacking γδ T cells from birth (Tcrd
-/- mice) examined the impact of these cells on ligature-induced periodontitis. Data obtained from those studies proposed either a protective effect or no impact to γδ T cells in this setting. Here, we addressed the role of γδ T cells in periodontitis using the recently developed Tcrd-GDL mice, enabling temporal ablation of γδ T cells. Specifically, the impact of γδ T cells during periodontitis was examined in 2 modalities: the ligature model and the oral infection model in which the pathogen Porphyromonas gingivalis was administrated via successive oral gavages. Ablation of γδ T cells during ligature-induced periodontitis had no impact on innate immune cell recruitment to the ligated gingiva. In addition, the number of osteoclasts and subsequent alveolar bone loss were unaffected. However, γδ T cells play a pathologic role during P. gingivalis infection, and their absence prevented alveolar bone loss. Further analysis revealed that γδ T cells were responsible for the recruitment of neutrophils and monocytes to the gingiva following the exposure to P. gingivalis. γδ T-cell ablation also downregulated osteoclastogenesis and dysregulated long-term immune responses in the gingiva. Collectively, this study demonstrates that whereas γδ T cells are dispensable to periodontitis induced by the ligature model, they play a deleterious role in the oral infection model by facilitating pathogen-induced bone-destructive immune responses. On a broader aspect, this study highlights the complex immunopathologic mechanisms involved in periodontal bone loss. [ABSTRACT FROM AUTHOR]- Published
- 2022
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4. Epithelial RANKL Limits Experimental Periodontitis via Langerhans Cells.
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Netanely Y, Barel O, Naamneh R, Jaber Y, Yacoub S, Saba Y, Zubeidat K, Saar O, Eli-Berchoer L, Yona S, Brand A, Capucha T, Wilensky A, Loser K, Clausen BE, and Hovav AH
- Abstract
Due to its capacity to drive osteoclast differentiation, the receptor activator of nuclear factor kappa-β ligand (RANKL) is believed to exert a pathological influence in periodontitis. However, RANKL was initially identified as an activator of dendritic cells (DCs), expressed by T cells, and exhibits diverse effects on the immune system. Hence, it is probable that RANKL, acting as a bridge between the bone and immune systems, plays a more intricate role in periodontitis. Using ligature-induced periodontitis (LIP), rapid alveolar bone loss was detected that was later halted even though the ligature was still present. This late phase of LIP was also linked with immunosuppressive conditions in the gingiva. Further investigation revealed that the ligature prompted an immediate migration of RANK-expressing Langerhans cells (LCs) and EpCAM
+ DCs, the antigen-presenting cells (APCs) of the gingival epithelium, to the lymph nodes, followed by an expansion of T regulatory (Treg) cells in the gingiva. Subsequently, the ligatured gingiva was repopulated by monocyte-derived RANK-expressing EpCAM+ DCs, while gingival epithelial cells upregulated RANKL expression. Blocking RANKL signaling with monoclonal antibodies significantly reduced the frequencies of Treg cells in the gingiva and prevented gingival immunosuppression. In addition, RANKL signaling facilitated the differentiation of LCs from bone marrow precursors. To further investigate the role of RANKL, we used K14-RANKL mice, in which RANKL is overexpressed by gingival epithelial cells. The elevated RANKL expression shifted the steady-state frequencies of LCs and EpCAM+ DCs within the epithelium, favoring LCs over EpCAM+ DCs. Following ligature placement, heightened levels of Treg cells were observed in the gingiva of K14-RANKL mice, and alveolar bone loss was significantly reduced. These findings suggest that RANKL-RANK interactions between gingival epithelial cells and APCs are crucial for suppressing gingival inflammation, highlighting a protective immunological role for RANKL in periodontitis that was overlooked due to its osteoclastogenic activity., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.- Published
- 2024
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5. Langerhans cells shape postnatal oral homeostasis in a mechanical-force-dependent but microbiota and IL17-independent manner.
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Jaber Y, Netanely Y, Naamneh R, Saar O, Zubeidat K, Saba Y, Georgiev O, Kles P, Barel O, Horev Y, Yosef O, Eli-Berchoer L, Nadler C, Betser-Cohen G, Shapiro H, Elinav E, Wilensky A, and Hovav AH
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- Adult, Humans, Interleukin-17, Homeostasis, Adaptive Immunity, Plaque, Amyloid, Langerhans Cells, Microbiota
- Abstract
The postnatal interaction between microbiota and the immune system establishes lifelong homeostasis at mucosal epithelial barriers, however, the barrier-specific physiological activities that drive the equilibrium are hardly known. During weaning, the oral epithelium, which is monitored by Langerhans cells (LC), is challenged by the development of a microbial plaque and the initiation of masticatory forces capable of damaging the epithelium. Here we show that microbial colonization following birth facilitates the differentiation of oral LCs, setting the stage for the weaning period, in which adaptive immunity develops. Despite the presence of the challenging microbial plaque, LCs mainly respond to masticatory mechanical forces, inducing adaptive immunity, to maintain epithelial integrity that is also associated with naturally occurring alveolar bone loss. Mechanistically, masticatory forces induce the migration of LCs to the lymph nodes, and in return, LCs support the development of immunity to maintain epithelial integrity in a microbiota-independent manner. Unlike in adult life, this bone loss is IL-17-independent, suggesting that the establishment of oral mucosal homeostasis after birth and its maintenance in adult life involve distinct mechanisms., (© 2023. Springer Nature Limited.)
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- 2023
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6. Porphyromonas gingivalis induction of TLR2 association with Vinculin enables PI3K activation and immune evasion.
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Pandi K, Angabo S, Gnanasekaran J, Makkawi H, Eli-Berchoer L, Glaser F, and Nussbaum G
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- Phosphatidylinositol 3-Kinases genetics, Phosphatidylinositol 3-Kinases metabolism, Immune Evasion, Vinculin metabolism, Base Composition, Phylogeny, RNA, Ribosomal, 16S, Sequence Analysis, DNA, Porphyromonas gingivalis genetics, Toll-Like Receptor 2 metabolism
- Abstract
Porphyromonas gingivalis is a Gram-negative anaerobic bacterium that thrives in the inflamed environment of the gingival crevice, and is strongly associated with periodontal disease. The host response to P. gingivalis requires TLR2, however P. gingivalis benefits from TLR2-driven signaling via activation of PI3K. We studied TLR2 protein-protein interactions induced in response to P. gingivalis, and identified an interaction between TLR2 and the cytoskeletal protein vinculin (VCL), confirmed using a split-ubiquitin system. Computational modeling predicted critical TLR2 residues governing the physical association with VCL, and mutagenesis of interface residues W684 and F719, abrogated the TLR2-VCL interaction. In macrophages, VCL knock-down led to increased cytokine production, and enhanced PI3K signaling in response to P. gingivalis infection, effects that correlated with increased intracellular bacterial survival. Mechanistically, VCL suppressed TLR2 activation of PI3K by associating with its substrate PIP2. P. gingivalis induction of TLR2-VCL led to PIP2 release from VCL, enabling PI3K activation via TLR2. These results highlight the complexity of TLR signaling, and the importance of discovering protein-protein interactions that contribute to the outcome of infection., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Pandi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
- Published
- 2023
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7. Microbiota-dependent and -independent postnatal development of salivary immunity.
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Zubeidat K, Jaber Y, Saba Y, Barel O, Naamneh R, Netanely Y, Horev Y, Eli-Berchoer L, Shhadeh A, Yosef O, Arbib E, Betser-Cohen G, Nadler C, Shapiro H, Elinav E, Aframian DJ, Wilensky A, and Hovav AH
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- Mice, Animals, Saliva, Salivary Glands, Immunoglobulin G, Receptors, Polymeric Immunoglobulin, Microbiota
- Abstract
While saliva regulates the interplay between the microbiota and the oral immune system, the mechanisms establishing postnatal salivary immunity are ill-defined. Here, we show that high levels of neutrophils and neonatal Fc receptor (FcRn)-transferred maternal IgG are temporarily present in the neonatal murine salivary glands in a microbiota-independent manner. During weaning, neutrophils, FcRn, and IgG decrease in the salivary glands, while the polymeric immunoglobulin receptor (pIgR) is upregulated in a growth arrest-specific 6 (GAS6)-dependent manner independent of the microbiota. Production of salivary IgA begins following weaning and relies on CD4-help, IL-17, and the microbiota. The weaning phase is characterized by a transient accumulation of dendritic cells capable of migrating from the oral mucosa to the salivary glands upon exposure to microbial challenges and activating T cells. This study reveals the postnatal mechanisms developed in the salivary glands to induce immunity and proposes the salivary glands as an immune inductive site., Competing Interests: Declaration of interests The authors declare no financial competing interests., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)
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- 2023
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8. Early antitumor activity of oral Langerhans cells is compromised by a carcinogen.
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Saba Y, Aizenbud I, Matanes D, Koren N, Barel O, Zubeidat K, Capucha T, David E, Eli-Berchoer L, Stoitzner P, Wilensky A, Amit I, Czerninski R, Yona S, and Hovav AH
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- 4-Nitroquinoline-1-oxide toxicity, Cell Line, Tumor, Dendritic Cells drug effects, Dendritic Cells pathology, Epithelial Cells metabolism, Epithelium drug effects, Epithelium pathology, Gene Expression Regulation, Neoplastic drug effects, Head and Neck Neoplasms genetics, Head and Neck Neoplasms immunology, Head and Neck Neoplasms pathology, Histones metabolism, Humans, Immunity drug effects, Langerhans Cells drug effects, Phagocytes drug effects, Phagocytes metabolism, Phagocytes pathology, Quinolones toxicity, Squamous Cell Carcinoma of Head and Neck genetics, Squamous Cell Carcinoma of Head and Neck immunology, Squamous Cell Carcinoma of Head and Neck pathology, T-Lymphocytes, Regulatory drug effects, T-Lymphocytes, Regulatory immunology, Tongue pathology, Transcriptome genetics, Antineoplastic Agents metabolism, Carcinogens toxicity, Langerhans Cells metabolism
- Abstract
Early diagnosis of oral squamous cell carcinoma (OSCC) remains an unmet clinical need. Therefore, elucidating the initial events of OSCC preceding tumor development could benefit OSCC prognosis. Here, we define the Langerhans cells (LCs) of the tongue and demonstrate that LCs protect the epithelium from carcinogen-induced OSCC by rapidly priming αβT cells capable of eliminating γH2AX
+ epithelial cells, whereas γδT and natural killer cells are dispensable. The carcinogen, however, dysregulates the epithelial resident mononuclear phagocytes, reducing LC frequencies, while dendritic cells (DCs), macrophages, and plasmacytoid DCs (pDCs) populate the epithelium. Single-cell RNA-sequencing analysis indicates that these newly differentiated cells display an immunosuppressive phenotype accompanied by an expansion of T regulatory (Treg) cells. Accumulation of the Treg cells was regulated, in part, by pDCs and precedes the formation of visible tumors. This suggests LCs play an early protective role during OSCC, yet the capacity of the carcinogen to dysregulate the differentiation of mononuclear phagocytes facilitates oral carcinogenesis., Competing Interests: The authors declare no competing interest., (Copyright © 2022 the Author(s). Published by PNAS.)- Published
- 2022
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9. Maturation of the neonatal oral mucosa involves unique epithelium-microbiota interactions.
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Koren N, Zubeidat K, Saba Y, Horev Y, Barel O, Wilharm A, Heyman O, Wald S, Eli-Berchoer L, Shapiro H, Nadler C, Elinav E, Wilensky A, Prinz I, Bercovier H, and Hovav AH
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- Animals, Animals, Newborn growth & development, Animals, Newborn microbiology, Interleukin-17 genetics, Mice, Mice, Inbred C57BL, Mice, Knockout, Mouth Mucosa cytology, Mouth Mucosa growth & development, Th17 Cells immunology, Bacterial Load, Mouth Mucosa immunology, Mouth Mucosa microbiology, Neutrophils immunology, Receptors, Antigen, T-Cell, gamma-delta immunology, Saliva microbiology
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Postnatal host-microbiota interplay governs mucosal homeostasis and is considered to have life-long health consequences. The intestine monolayer epithelium is critically involved in such early-life processes; nevertheless, the role of the oral multilayer epithelium remains ill defined. We demonstrate that unlike the intestine, the neonate oral cavity is immensely colonized by the microbiota that decline to adult levels during weaning. Neutrophils are present in the oral epithelium prenatally, and exposure to the microbiota postnatally further recruits them to the preamble neonatal epithelium by γδT17 cells. These neutrophils virtually disappear during weaning as the epithelium seals. The neonate and adult epithelium display distinct turnover kinetics and transcriptomic signatures, with neonate epithelium reminiscent of the signature found in germ-free mice. Microbial reduction during weaning is mediated by the upregulation of saliva production and induction of salivary antimicrobial components by the microbiota. Collectively, unique postnatal interactions between the multilayer epithelium and microbiota shape oral homeostasis., Competing Interests: Declaration of Interests The authors declare no financial competing interests. Dr. Eran Elinav serves as on the advisory board of this journal., (Copyright © 2020 Elsevier Inc. All rights reserved.)
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- 2021
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10. Niche rather than origin dysregulates mucosal Langerhans cells development in aged mice.
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Horev Y, Salameh R, Nassar M, Capucha T, Saba Y, Barel O, Zubeidat K, Matanes D, Leibovich A, Heyman O, Eli-Berchoer L, Hanhan S, Betser-Cohen G, Shapiro H, Elinav E, Bercovier H, Wilensky A, and Hovav AH
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- Age Factors, Aging physiology, Animals, Biomarkers, Bone Morphogenetic Protein 7 genetics, Bone Morphogenetic Protein 7 metabolism, Cellular Microenvironment genetics, Cellular Senescence genetics, Cellular Senescence immunology, Epidermal Cells immunology, Epidermal Cells metabolism, Epidermis immunology, Epidermis metabolism, Epidermis microbiology, Gene Expression, Gingiva immunology, Gingiva metabolism, Gingiva microbiology, Immunophenotyping, Langerhans Cells cytology, Mice, Microbiota, Mucous Membrane microbiology, Transforming Growth Factor beta1 genetics, Transforming Growth Factor beta1 metabolism, Cell Differentiation genetics, Cell Differentiation immunology, Cellular Microenvironment immunology, Langerhans Cells immunology, Langerhans Cells metabolism, Mucous Membrane immunology, Mucous Membrane metabolism
- Abstract
Unlike epidermal Langerhans cells (LCs) that originate from embryonic precursors and are self-renewed locally, mucosal LCs arise and are replaced by circulating bone marrow (BM) precursors throughout life. While the unique lifecycle of epidermal LCs is associated with an age-dependent decrease in their numbers, whether and how aging has an impact on mucosal LCs remains unclear. Focusing on gingival LCs we found that mucosal LCs are reduced with age but exhibit altered morphology with that observed in aged epidermal LCs. The reduction of gingival but not epidermal LCs in aged mice was microbiota-dependent; nevertheless, the impact of the microbiota on gingival LCs was indirect. We next compared the ability of young and aged BM precursors to differentiate to mucosal LCs. Mixed BM chimeras, as well as differentiation cultures, demonstrated that aged BM has intact if not superior capacity to differentiate into LCs than young BM. This was in line with the higher percentages of mucosal LC precursors, pre-DCs, and monocytes, detected in aged BM. These findings suggest that while aging is associated with reduced LC numbers, the niche rather than the origin controls this process in mucosal barriers.
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- 2020
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11. Intracellular Porphyromonas gingivalis Promotes the Tumorigenic Behavior of Pancreatic Carcinoma Cells.
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Gnanasekaran J, Binder Gallimidi A, Saba E, Pandi K, Eli Berchoer L, Hermano E, Angabo S, Makkawi HA, Khashan A, Daoud A, Elkin M, and Nussbaum G
- Abstract
Porphyromonas gingivalis is a member of the dysbiotic oral microbiome associated with oral inflammation and periodontal disease. Intriguingly, epidemiological studies link P. gingivalis to an increased risk of pancreatic cancer. Given that oral bacteria are detected in human pancreatic cancer, and both mouse and human pancreata harbor microbiota, we explored the involvement of P. gingivalis in pancreatic tumorigenesis using cell lines and a xenograft model. Live P. gingivalis induced proliferation of pancreatic cancer cells; however, surprisingly, this effect was independent of Toll-like receptor 2, the innate immune receptor that is engaged in response to P. gingivalis on other cancer and immune cells, and is required for P. gingivalis to induce alveolar bone resorption. Instead, we found that P. gingivalis survives inside pancreatic cancer cells, a trait that can be enhanced in vitro and is increased by hypoxia, a central characteristic of pancreatic cancer. Increased tumor cell proliferation was related to the degree of intracellular persistence, and infection of tumor cells with P. gingivalis led to enhanced growth in vivo. To the best of our knowledge, this study is the first to demonstrate the direct effect of exposure to P. gingivalis on the tumorigenic behavior of pancreatic cancer cell lines. Our findings shed light on potential mechanisms underlying the pancreatic cancer-periodontitis link.
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- 2020
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12. Myd88 plays a major role in the keratinocyte response to infection with Porphyromonas gingivalis.
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Polak D, Zigron A, Eli-Berchoer L, Shapira L, and Nussbaum G
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- Animals, Antimicrobial Cationic Peptides immunology, Bacterial Adhesion, Fusobacterium nucleatum, Keratinocytes immunology, Mice, Mice, Knockout, Bacteroidaceae Infections immunology, Keratinocytes microbiology, Myeloid Differentiation Factor 88 immunology, Porphyromonas gingivalis
- Abstract
Aim: To explore the role of keratinocyte myeloid differentiation primary response 88 (MyD88) expression in the adhesion of Porphyromonas gingivalis to the cells and its subsequent invasion and intracellular survival., Materials and Methods: Primary mouse keratinocytes from wild-type (WT) or Myd88
-/- mice were infected with P gingivalis alone or co-infected with Fusobacterium nucleatum. Bacterial adhesion and invasion were measured using fluorescent microscopy and flow cytometry, and intracellular survival in keratinocytes was quantified by an antibiotic protection assay. Keratinocyte expression of antimicrobial peptides was measured by real-time PCR., Results: In the absence of MyD88, P gingivalis adherence, invasion, and intracellular survival were enhanced compared with WT keratinocytes. The presence of F nucleatum during infection increased the adhesion of P gingivalis to WT keratinocytes but reduced the adhesion to Myd88-/- keratinocytes. Fusobacterium nucleatum improved mildly the invasion and survival of P gingivalis in both cell types. Baseline expression of beta-defensin 2, 3, 4 and RegIII-γ was elevated in Myd88-/- keratinocytes compared to WT cells; however, following infection beta-defensin expression was strongly induced in WT cells but decreased dramatically in the MyD88 deficient cells., Conclusion: In the absence of MyD88 expression, P gingivalis adhesion to keratinocytes is improved, and invasion and intracellular survival are increased. Furthermore, keratinocyte infection by P gingivalis induces antimicrobial peptide expression in a MyD88-dependent manner. Thus, MyD88 plays a key role in the interaction between P gingivalis and keratinocytes., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)- Published
- 2019
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13. Platelet-derived growth factor activates nociceptive neurons by inhibiting M-current and contributes to inflammatory pain.
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Barkai O, Puig S, Lev S, Title B, Katz B, Eli-Berchoer L, Gutstein HB, and Binshtok AM
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- Action Potentials drug effects, Action Potentials physiology, Animals, Ganglia, Spinal metabolism, Ganglia, Spinal physiopathology, Hyperalgesia metabolism, Hyperalgesia physiopathology, Male, Nociceptors drug effects, Pain metabolism, Pain physiopathology, Pain Measurement drug effects, Pain Measurement methods, Platelet-Derived Growth Factor pharmacology, Rats, Sprague-Dawley, Sensory Receptor Cells drug effects, Inflammation drug therapy, Nociceptors physiology, Platelet-Derived Growth Factor metabolism, Sensory Receptor Cells metabolism
- Abstract
Endogenous inflammatory mediators contribute to the pathogenesis of pain by acting on nociceptors, specialized sensory neurons that detect noxious stimuli. Here, we describe a new factor mediating inflammatory pain. We show that platelet-derived growth factor (PDGF)-BB applied in vitro causes repetitive firing of dissociated nociceptor-like rat dorsal root ganglion neurons and decreased their threshold for action potential generation. Injection of PDGF-BB into the paw produced nocifensive behavior in rats and led to thermal and mechanical pain hypersensitivity. We further detailed the biophysical mechanisms of these PDGF-BB effects and show that PDGF receptor-induced inhibition of nociceptive M-current underlies PDGF-BB-mediated nociceptive hyperexcitability. Moreover, in vivo sequestration of PDGF or inhibition of the PDGF receptor attenuates acute formalin-induced inflammatory pain. Our discovery of a new pain-facilitating proinflammatory mediator, which by inhibiting M-current activates nociceptive neurons and thus contributes to inflammatory pain, improves our understanding of inflammatory pain pathophysiology and may have important clinical implications for pain treatment.
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- 2019
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14. Mutual interplay between IL-17-producing γδT cells and microbiota orchestrates oral mucosal homeostasis.
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Wilharm A, Tabib Y, Nassar M, Reinhardt A, Mizraji G, Sandrock I, Heyman O, Barros-Martins J, Aizenbud Y, Khalaileh A, Eli-Berchoer L, Elinav E, Wilensky A, Förster R, Bercovier H, Prinz I, and Hovav AH
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- Animals, Biofilms, Gingiva immunology, Gingiva microbiology, Inflammation immunology, Mice, Homeostasis, Interleukin-17 biosynthesis, Microbiota, Mouth Mucosa microbiology, Receptors, Antigen, T-Cell, gamma-delta metabolism, T-Lymphocytes metabolism
- Abstract
γδT cells are a major component of epithelial tissues and play a role in tissue homeostasis and host defense. γδT cells also reside in the gingiva, an oral tissue covered with specialized epithelium that continuously monitors the challenging dental biofilm. Whereas most research on intraepithelial γδT cells focuses on the skin and intestine epithelia, our knowledge on these cells in the gingiva is still incomplete. In this study, we demonstrate that even though the gingiva develops after birth, the majority of gingival γδT cells are fetal thymus-derived Vγ6
+ cells, and to a lesser extent Vγ1+ and Vγ4+ cells. Furthermore, we show that γδT cells are motile and locate preferentially in the epithelium adjacent to the biofilm. Vγ6+ cells represent the major source of IL-17-producing cells in the gingiva. Chimeric mice and parabiosis experiments indicated that the main fraction of gingival γδT cells is radioresistant and tissue-resident, persisting locally independent of circulating γδT cells. Notably, gingival γδT cell homeostasis is regulated by the microbiota as the ratio of Vγ6+ and Vγ4+ cells was reversed in germ-free mice, and their activation state was decreased. As a consequence, conditional ablation of γδT cells results in elevated gingival inflammation and subsequent alterations of oral microbial diversity. Taken together, these findings suggest that oral mucosal homeostasis is shaped by reciprocal interplays between γδT cells and local microbiota., Competing Interests: The authors declare no conflict of interest.- Published
- 2019
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15. Cell-intrinsic regulation of murine epidermal Langerhans cells by protein S.
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Tabib Y, Jaber NS, Nassar M, Capucha T, Mizraji G, Nir T, Koren N, Aizenbud I, Maimon A, Eli-Berchoer L, Wilensky A, Burstyn-Cohen T, and Hovav AH
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- Animals, Bone Marrow metabolism, Calcium-Binding Proteins, Cell Differentiation physiology, Homeostasis physiology, Keratinocytes metabolism, Mice, Mice, Inbred C57BL, Monocytes metabolism, Proto-Oncogene Proteins metabolism, Receptor Protein-Tyrosine Kinases metabolism, Signal Transduction physiology, c-Mer Tyrosine Kinase metabolism, Carrier Proteins metabolism, Epidermis metabolism, Langerhans Cells metabolism, Protein S metabolism
- Abstract
AXL, a member of the TYRO3, AXL, and MERTK (TAM) receptor tyrosine kinase family, has been shown to play a role in the differentiation and activation of epidermal Langerhans cells (LCs). Here, we demonstrate that growth arrest-specific 6 (GAS6) protein, the predominant ligand of AXL, has no impact on LC differentiation and homeostasis. We thus examined the role of protein S (PROS1), the other TAM ligand acting primarily via TYRO3 and MERTK, in LC function. Genetic ablation of PROS1 in keratinocytes resulted in a typical postnatal differentiation of LCs; however, a significant reduction in LC frequencies was observed in adult mice due to increased apoptosis. This was attributed to altered expression of cytokines involved in LC development and tissue homeostasis within keratinocytes. PROS1 was then excised in LysM
+ cells to target LCs at early embryonic developmental stages, as well as in adult monocytes that also give rise to LCs. Differentiation and homeostasis of LCs derived from embryonic precursors was not affected following Pros1 ablation. However, differentiation of LCs from bone marrow (BM) precursors in vitro was accelerated, as was their capability to reconstitute epidermal LCs in vivo. These reveal an inhibitory role for PROS1 on BM-derived LCs. Collectively, this study highlights a cell-specific regulation of LC differentiation and homeostasis by TAM signaling., Competing Interests: The authors declare no conflict of interest.- Published
- 2018
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16. Multiple Regulatory Levels of Growth Arrest-Specific 6 in Mucosal Immunity Against an Oral Pathogen.
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Nassar M, Tabib Y, Capucha T, Mizraji G, Nir T, Saba F, Salameh R, Eli-Berchoer L, Wilensky A, Burstyn-Cohen T, and Hovav AH
- Abstract
Growth arrest-specific 6 (GAS6) expressed by oral epithelial cells and dendritic cells (DCs) was shown to play a critical role in the maintenance of oral mucosal homeostasis. In this study, we demonstrate that the induction of pathogen-specific oral adaptive immune responses is abrogated in Gas6
-/- mice. Further analysis revealed that GAS6 induces simultaneously both pro- and anti-inflammatory regulatory pathways upon infection. On one hand, GAS6 upregulates expression of adhesion molecules on blood vessels, facilitating extravasation of innate inflammatory cells to the oral mucosa. GAS6 also elevates expression of CCL19 and CCL21 chemokines and enhances migration of oral DCs to the lymph nodes. On the other hand, expression of pro-inflammatory molecules in the oral mucosa are downregulated by GAS6. Moreover, GAS6 inhibits DC maturation and reduces antigen presentation to T cells by DCs. These data suggest that GAS6 facilitates bi-directional trans-endothelial migration of inflammatory cells and DCs, whereas inhibiting mucosal activation and T-cell stimulation. Thus, the orchestrated complex activity of GAS6 enables the development of a rapid and yet restrained mucosal immunity to oral pathogens.- Published
- 2018
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17. Sequential BMP7/TGF-β1 signaling and microbiota instruct mucosal Langerhans cell differentiation.
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Capucha T, Koren N, Nassar M, Heyman O, Nir T, Levy M, Zilberman-Schapira G, Zelentova K, Eli-Berchoer L, Zenke M, Hieronymus T, Wilensky A, Bercovier H, Elinav E, Clausen BE, and Hovav AH
- Subjects
- Animals, Antigens, Surface genetics, Antigens, Surface metabolism, Bone Morphogenetic Protein 7 genetics, Bone Morphogenetic Protein Receptors, Type I metabolism, Cell Differentiation genetics, Cell Differentiation immunology, Humans, Immunity, Mucosal, Langerhans Cells cytology, Langerhans Cells metabolism, Lectins, C-Type deficiency, Lectins, C-Type genetics, Lectins, C-Type metabolism, Male, Mannose-Binding Lectins deficiency, Mannose-Binding Lectins genetics, Mannose-Binding Lectins metabolism, Mice, Mice, Inbred C57BL, Mice, Knockout, Mouth Mucosa cytology, Mouth Mucosa immunology, Receptor, Transforming Growth Factor-beta Type I metabolism, Signal Transduction immunology, Stem Cells cytology, Stem Cells immunology, Transcriptome, Transforming Growth Factor beta1 genetics, Up-Regulation, Bone Morphogenetic Protein 7 immunology, Langerhans Cells immunology, Microbiota immunology, Transforming Growth Factor beta1 immunology
- Abstract
Mucosal Langerhans cells (LCs) originate from pre-dendritic cells and monocytes. However, the mechanisms involved in their in situ development remain unclear. Here, we demonstrate that the differentiation of murine mucosal LCs is a two-step process. In the lamina propria, signaling via BMP7-ALK3 promotes translocation of LC precursors to the epithelium. Within the epithelium, TGF-β1 finalizes LC differentiation, and ALK5 is crucial to this process. Moreover, the local microbiota has a major impact on the development of mucosal LCs, whereas LCs in turn maintain mucosal homeostasis and prevent tissue destruction. These results reveal the differential and sequential role of TGF-β1 and BMP7 in LC differentiation and highlight the intimate interplay of LCs with the microbiota., (© 2018 Capucha et al.)
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- 2018
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18. Porphyromonas gingivalis Promotes Unrestrained Type I Interferon Production by Dysregulating TAM Signaling via MYD88 Degradation.
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Mizraji G, Nassar M, Segev H, Sharawi H, Eli-Berchoer L, Capucha T, Nir T, Tabib Y, Maimon A, Dishon S, Shapira L, Nussbaum G, Wilensky A, and Hovav AH
- Subjects
- Alveolar Bone Loss complications, Alveolar Bone Loss immunology, Alveolar Bone Loss pathology, Animals, Bacteroidaceae Infections complications, Bacteroidaceae Infections immunology, Bacteroidaceae Infections microbiology, Bone Resorption complications, Bone Resorption immunology, Bone Resorption pathology, Dendritic Cells immunology, Gingiva microbiology, Gingiva pathology, Humans, Interferon Type I metabolism, Leukocytes pathology, Lymph Nodes pathology, Mice, Mouth Mucosa microbiology, Mouth Mucosa pathology, Periodontitis immunology, Periodontitis microbiology, Periodontitis pathology, Interferon Type I biosynthesis, Myeloid Differentiation Factor 88 metabolism, Porphyromonas gingivalis physiology, Proteolysis, Receptors, Cell Surface metabolism, Signal Transduction
- Abstract
Whereas type I interferons (IFNs-I) were proposed to be elevated in human periodontitis, their role in the disease remains elusive. Using a bacterial-induced model of murine periodontitis, we revealed a prolonged elevation in IFN-I expression. This was due to the downregulation of TAM signaling, a major negative regulator of IFN-I. Further examination revealed that the expression of certain TAM components was reduced as a result of prolonged degradation of MYD88 by the infection. As a result of such prolonged IFN-I production, innate immunological functions of the gingiva were disrupted, and CD4
+ T cells were constitutively primed by dendritic cells, leading to elevated RANKL expression and, subsequently, alveolar bone loss (ABL). Blocking IFN-I signaling restored proper immunological function and prevented ABL. Importantly, a loss of negative regulation on IFN-I expression by TAM signaling was also evident in periodontitis patients. These findings thus suggest a role for IFN-I in the pathogenesis of periodontitis., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2017
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19. CX3CR1hi Monocyte/Macrophages Support Bacterial Survival and Experimental Infection-Driven Bone Resorption.
- Author
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Steinmetz O, Hoch S, Avniel-Polak S, Gavish K, Eli-Berchoer L, Wilensky A, and Nussbaum G
- Subjects
- Animals, Bacteroidaceae Infections immunology, Bacteroidaceae Infections microbiology, CX3C Chemokine Receptor 1, Host-Pathogen Interactions immunology, Mice, Mice, Inbred C57BL, Mice, Knockout, Neutrophils immunology, Periodontitis immunology, Periodontitis microbiology, Receptors, CCR2 genetics, Receptors, Chemokine genetics, Alveolar Bone Loss immunology, Alveolar Bone Loss microbiology, Macrophages immunology, Monocytes immunology, Porphyromonas gingivalis immunology, Porphyromonas gingivalis pathogenicity, Receptors, CCR2 metabolism, Receptors, Chemokine metabolism
- Abstract
Porphyromonas gingivalis,an anaerobic bacterium strongly linked to infection-driven inflammatory bone erosion, thrives within a highly inflamed milieu and disseminates to distant sites, such as atherosclerotic plaque. We examined the role of monocyte/macrophages in determining the outcome of infection with P. gingivalis. Surprisingly, transient monocyte/macrophage depletion led to greatly improved clearance of P. gingivalis. The chemokine receptors CCR2 and CX3CR1 play a major role in monocyte recruitment and differentiation to Ly6C(hi) vs CX3CR1(hi) subsets, respectively. To determine the contribution of particular monocyte/macrophage subsets to bacterial survival, we challenged chemokine receptor knockout mice and found that P. gingivalis clearance is significantly improved in the absence of CX3CR1. CX3CR1(hi) monocyte/macrophages promote P. gingivalis survival by downregulating neutrophil phagocytosis. Furthermore, CX3CR1 knockout mice resist bone resorption in the oral cavity following challenge with P. gingivalis Our findings provide an explanation for bacterial coexistence alongside an activate neutrophil infiltrate., (© The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.)
- Published
- 2016
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20. Second-generation Langerhans cells originating from epidermal precursors are essential for CD8+ T cell priming.
- Author
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Elnekave M, Furmanov K, Shaul Y, Capucha T, Eli-Berchoer L, Zelentsova K, Clausen BE, and Hovav AH
- Subjects
- Animals, CD11c Antigen metabolism, Cell Differentiation immunology, Chemokine CCL20 immunology, Clodronic Acid, Dendritic Cells metabolism, Heparin-binding EGF-like Growth Factor, Intercellular Signaling Peptides and Proteins genetics, Mice, Mice, Inbred C57BL, Mice, Knockout, Plasmids genetics, Receptors, CCR2 deficiency, Receptors, CCR2 genetics, Receptors, CCR2 immunology, Skin cytology, Skin immunology, CD8-Positive T-Lymphocytes immunology, Dendritic Cells immunology, Giant Cells, Langhans immunology, Lymphocyte Activation immunology
- Abstract
In vivo studies questioned the ability of Langerhans cells (LCs) to mediate CD8(+) T cell priming. To address this issue, we used intradermal immunization with plasmid DNA, a system in which activation of CD8(+) T cells depends on delayed kinetics of Ag presentation. We found that dendritic cells (DCs) located in the skin at the time of immunization have limited ability to activate CD8(+) T cells. This activity was mediated by a second generation of DCs that differentiated in the skin several days after immunization, as well as by lymph node-resident DCs. Intriguingly, CD8(+) T cell responses were not affected following treatment with clodronate liposomes, immunization of CCR2(-/-) mice, or local neutralization of CCL20. This suggests that local, rather than blood-derived, DC precursors mediate CD8(+) T cell priming. Analysis of DC differentiation in the immunized skin revealed a gradual increase in the number of CD11c(+) cells, which reached their maximum 2 wk after immunization. A similar differentiation kinetics was observed for LCs, with the majority of differentiating LCs proliferating in situ from epidermal precursors. By using B6/Langerin-diphtheria toxin receptor chimeric mice and LC ablation, we demonstrated that epidermal LCs were crucial for the elicitation of CD8(+) T cell responses in vivo. Furthermore, LCs isolated from lymph nodes 2 wk after immunization contained the immunization plasmid and directly activated Ag-specific CD8(+) T cells ex vivo. Thus, these results indicate that second-generation Ag-expressing LCs differentiating from epidermal precursors directly prime CD8(+) T cells and are essential for optimal cellular immune responses following immunization with plasmid DNA.
- Published
- 2014
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21. Diminished Memory T-Cell Expansion Due to Delayed Kinetics of Antigen Expression by Lentivectors.
- Author
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Furmanov K, Elnekave M, Sa'eed A, Segev H, Eli-Berchoer L, Kotton DN, Bachrach G, and Hovav AH
- Subjects
- Animals, Antigens, Viral immunology, CD8-Positive T-Lymphocytes cytology, Cell Proliferation, Kinetics, Lentivirus immunology, Mice, Mice, Inbred C57BL, CD8-Positive T-Lymphocytes immunology, Genetic Vectors, Immunologic Memory, Lentivirus genetics
- Abstract
Memory CD8(+) T lymphocytes play a central role in protective immunity. In attempt to increase the frequencies of memory CD8(+) T cells, repeated immunizations with viral vectors are regularly explored. Lentivectors have emerged as a powerful vaccine modality with relatively low pre-existing and anti-vector immunity, thus, thought to be ideal for boosting memory T cells. Nevertheless, we found that lentivectors elicited diminished secondary T-cell responses that did not exceed those obtained by priming. This was not due to the presence of anti-vector immunity, as limited secondary responses were also observed following heterologous prime-boost immunizations. By dissecting the mechanisms involved in this process, we demonstrate that lentivectors trigger exceptionally slow kinetics of antigen expression, while optimal activation of lentivector-induced T cells relays on durable expression of the antigen. These qualities hamper secondary responses, since lentivector-encoded antigen is rapidly cleared by primary cytotoxic T cells that limit its presentation by dendritic cells. Indeed, blocking antigen clearance by cytotoxic T cells via FTY720 treatment, fully restored antigen presentation. Taken together, while low antigen expression is expected during secondary immunization with any vaccine vector, our results reveal that the intrinsic delayed expression kinetics of lentiviral-encoded antigen, further dampens secondary CD8(+) T-cell expansion.
- Published
- 2013
- Full Text
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22. Langerhans cells down-regulate inflammation-driven alveolar bone loss.
- Author
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Arizon M, Nudel I, Segev H, Mizraji G, Elnekave M, Furmanov K, Eli-Berchoer L, Clausen BE, Shapira L, Wilensky A, and Hovav AH
- Subjects
- Alveolar Bone Loss etiology, Animals, Antigens, CD genetics, Antigens, CD immunology, Bacteroidaceae Infections complications, Bacteroidaceae Infections immunology, Base Sequence, CD4-Positive T-Lymphocytes immunology, DNA Primers genetics, Disease Models, Animal, Down-Regulation immunology, Heparin-binding EGF-like Growth Factor, Humans, Inflammation complications, Inflammation immunology, Intercellular Signaling Peptides and Proteins genetics, Intercellular Signaling Peptides and Proteins immunology, Interferon-gamma metabolism, Interleukin-10 metabolism, Interleukin-17 metabolism, Langerhans Cells classification, Lectins, C-Type genetics, Lectins, C-Type immunology, Lymphocyte Activation, Mannose-Binding Lectins genetics, Mannose-Binding Lectins immunology, Mice, Mice, Inbred C57BL, Mice, Transgenic, Porphyromonas gingivalis immunology, RANK Ligand metabolism, T-Lymphocytes, Regulatory immunology, Alveolar Bone Loss immunology, Alveolar Bone Loss prevention & control, Langerhans Cells immunology
- Abstract
Excessive bone resorption is frequently associated with chronic infections and inflammatory diseases. Whereas T cells were demonstrated to facilitate osteoclastogenesis in such diseases, the role of dendritic cells, the most potent activators of naive T cells, remains unclear. Using a model involving inflammation-driven alveolar bone loss attributable to infection, we showed that in vivo ablation of Langerhans cells (LCs) resulted in enhanced bone loss. An increased infiltration of B and T lymphocytes into the tissue surrounding the bone was observed in LC-ablated mice, including receptor activator of NF-κB ligand (RANKL)-expressing CD4(+) T cells with known capabilities of altering bone homeostasis. In addition, the absence of LCs significantly reduced the numbers of CD4(+)Foxp3(+) T-regulatory cells in the tissue. Further investigation revealed that LCs were not directly involved in presenting antigens to T cells. Nevertheless, despite their low numbers in the tissue, the absence of LCs resulted in an elevated activation of CD4(+) but not CD8(+) T cells. This activation involved elevated production of IFN-γ but not IL-17 or IL-10 cytokines. Our data, thus, reveal a protective immunoregulatory role for LCs in inflammation-induced alveolar bone resorption, by inhibiting IFN-γ secretion and excessive activation of RANKL(+)CD4(+) T cells with a capability of promoting osteoclastogenesis.
- Published
- 2012
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23. Physiological and molecular evidence of heat acclimation memory: a lesson from thermal responses and ischemic cross-tolerance in the heart.
- Author
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Tetievsky A, Cohen O, Eli-Berchoer L, Gerstenblith G, Stern MD, Wapinski I, Friedman N, and Horowitz M
- Subjects
- Animals, DNA-Binding Proteins genetics, DNA-Binding Proteins metabolism, Gene Expression Regulation, Genotype, Heart Ventricles pathology, Heart Ventricles physiopathology, Heat Shock Transcription Factors, Heat-Shock Proteins genetics, Heat-Shock Proteins metabolism, Male, Memory, Myocardial Infarction pathology, Myocardial Infarction physiopathology, Myocytes, Cardiac pathology, Phenotype, Phosphorylation, Rats, Time Factors, Transcription Factors genetics, Transcription Factors metabolism, bcl-X Protein genetics, bcl-X Protein metabolism, Acclimatization physiology, Heart physiopathology, Heat-Shock Response, Hot Temperature, Myocardial Ischemia physiopathology
- Abstract
Sporadic findings in humans suggest that reinduction of heat acclimation (AC) after its loss occurs markedly faster than that during the initial AC session. Animal studies substantiated that the underlying acclimatory processes are molecular. Here we test the hypothesis that faster reinduction of AC (ReAC) implicates "molecular memory." In vivo measurements of colonic temperature profiles during heat stress and ex vivo assessment of cross-tolerance to ischemia-reperfusion or anoxia insults in the heart demonstrated that ReAC only needs 2 days vs. the 30 days required for the initial development of AC. Stress gene profiling in the experimental groups highlighted clusters of transcriptionally activated genes (37%), which included heat shock protein (HSP) genes, antiapoptotic genes, and chromatin remodeling genes. Despite a return of the physiological phenotype to its preacclimation state, after a 1 mo deacclimation (DeAC) period, the gene transcripts did not resume their preacclimation levels, suggesting a dichotomy between genotype and phenotype in this system. Individual detection of hsp70 and hsf1 transcripts agreed with these findings. HSP72, HSF1/P-HSF1, and Bcl-xL protein profiles followed the observed dichotomized genomic response. In contrast, HSP90, an essential cytoprotective component mismatched transcriptional activation upon DeAC. The uniform activation of the similarly responding gene clusters upon De-/ReAC implies that reacclimatory phenotypic plasticity is associated with upstream denominators. During AC, DeAC, and ReAC, the maintenance of elevated/phosphorylated HSF1 protein levels and transcriptionally active chromatin remodeling genes implies that chromatin remodeling plays a pivotal role in the transcriptome profile and in preconditioning to rapid cytoprotective acclimatory memory.
- Published
- 2008
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24. Acclimatory-phase specificity of gene expression during the course of heat acclimation and superimposed hypohydration in the rat hypothalamus.
- Author
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Schwimmer H, Eli-Berchoer L, and Horowitz M
- Subjects
- Animals, Appetite Regulation genetics, Appetite Regulation physiology, Carrier Proteins genetics, Carrier Proteins physiology, Dehydration genetics, Energy Metabolism genetics, Energy Metabolism physiology, Heat Stress Disorders genetics, Heat Stress Disorders physiopathology, Hypothalamus chemistry, Ion Channels genetics, Ion Channels physiology, Male, Oligonucleotide Array Sequence Analysis, RNA, Messenger analysis, RNA, Messenger genetics, Rats, Rats, Inbred Strains, Receptors, G-Protein-Coupled genetics, Receptors, G-Protein-Coupled physiology, Synaptic Transmission genetics, Synaptic Transmission physiology, Acclimatization genetics, Acclimatization physiology, Dehydration physiopathology, Gene Expression Regulation physiology, Hot Temperature, Hypothalamus physiopathology
- Abstract
The induction of the heat-acclimated phenotype involves reprogramming the expression of genes encoding both constitutive and inducible proteins. In this investigation, we studied the global genomic response in the hypothalamus during heat acclimation, with and without combined hypohydration stress. Rats were acclimated for 2 days (STHA) or for 30 days (LTHA) at 34 degrees C. Hypohydration (10% decrease in body weight) was attained by water deprivation. 32P-labeled RNA samples from the hypothalamus were hybridized onto cDNA Atlas array (Clontech no. 1.2) membranes. Clustering and functional analyses of the expression profile of a battery of genes representing various central regulatory functions of body homeostasis demonstrated a biphasic acclimation profile with a transient upregulation of genes encoding ion channels, transporters, and transmitter signaling upon STHA. After LTHA, most genes returned to their preacclimation expression levels. In both STHA and LTHA, genes encoding hormones and neuropeptides, linked with metabolic rate and food intake, were downregulated. This genomic profile, demonstrating an enhanced transcription of genes linked with neuronal excitability during STHA and enhanced metabolic efficiency upon LTHA, is consistent with our previously established integrative acclimation model. The response to hypohydration was characterized by an upregulation of a large number of genes primarily associated with the regulation of ion channels, cell volume, and neuronal excitability. During STHA, the response was transiently desensitized, recovering upon LTHA. We conclude that hypohydration overrides the heat acclimatory status. It is notable that STHA and hypohydration gene profiles are analogous with the physiological profile described in the response to various types of brain injury.
- Published
- 2006
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- View/download PDF
25. Heat intolerance: does gene transcription contribute?
- Author
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Moran DS, Eli-Berchoer L, Heled Y, Mendel L, Schocina M, and Horowitz M
- Subjects
- Adult, Body Temperature, DNA-Binding Proteins genetics, DNA-Binding Proteins metabolism, Exercise physiology, HSP72 Heat-Shock Proteins genetics, HSP72 Heat-Shock Proteins metabolism, HSP90 Heat-Shock Proteins genetics, HSP90 Heat-Shock Proteins metabolism, Heat Shock Transcription Factors, Heat Stress Disorders genetics, Heat Stress Disorders physiopathology, Hot Temperature, Humans, Lymphocytes metabolism, Male, NF-kappa B genetics, NF-kappa B metabolism, RNA, Messenger metabolism, Transcription Factors genetics, Transcription Factors metabolism, Vasomotor System physiopathology, Gene Expression Regulation, Heat Stress Disorders metabolism, Transcription, Genetic
- Abstract
During exertion in the heat, heat-intolerant (HI) subjects have a physiological disability in metabolic heat dissipation. The HI state is either permanent or temporary, depending on whether it stems from transient predisposing factors or inherent thermoregulatory dysfunction. In this investigation, we studied protein levels of heat shock protein (HSP) 70 and HSP72, HSP90, bcl-2xL, glutathione S-transferase-p, heat shock factor-1, TATA-binding protein-associated factor, and NF-kappaB transcripts using Western blot and quantitative RT-PCR, respectively, in lymphocytes of HI and tolerant (T) male volunteers of similar anthropometric features. Measurements were made from blood drawn before, during the heat tolerance test (3.5 mph, 40 degrees C, 40% relative humidity, 2 h), and 1 h after recovery at 24 degrees C. Rectal and skin temperatures, as well as heart rate, were continuously recorded. Of 58 subjects, 7 were identified as HI, with a significantly higher physiological strain index than in the T group (6.3 +/- 0.9 vs. 3.8 +/- 0.6, P < 0.001). The responsiveness of the vasculature to thermal stimuli was decreased in the HI group, as indicated by rectal temperature minus skin temperature. The HSP72 level in the HI group dropped during the recovery session (P < 0.01), whereas that of the T group continued to rise. A significantly increased expression of the transcription factors in the T subjects and significantly decreased expression in the HI group (P < 0.009, 0.013, and 0.005 for heat shock factor-1, NF-kappaB, and TATA-binding protein-associated factor, respectively) points to impaired transcriptional processes in the HI group. Our data suggest that transcriptional malfunction and sluggishness of the vasculature to thermal stimuli are predisposing factors in the HI group.
- Published
- 2006
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- View/download PDF
26. HIF-1alpha-targeted pathways are activated by heat acclimation and contribute to acclimation-ischemic cross-tolerance in the heart.
- Author
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Maloyan A, Eli-Berchoer L, Semenza GL, Gerstenblith G, Stern MD, and Horowitz M
- Subjects
- Animals, Blotting, Western, Body Temperature, Caenorhabditis elegans, Cell Nucleus metabolism, Cytosol metabolism, Erythropoietin metabolism, Heart physiology, Heme Oxygenase-1 metabolism, Hot Temperature, Hypoxia metabolism, Immunohistochemistry, Immunoprecipitation, Ischemia metabolism, Kidney metabolism, Male, Microscopy, Confocal, Microscopy, Fluorescence, Models, Statistical, Myocardium metabolism, Myocardium pathology, RNA, Messenger metabolism, Rats, Receptors, Erythropoietin metabolism, Reperfusion Injury, Reverse Transcriptase Polymerase Chain Reaction, Subcellular Fractions metabolism, Temperature, Time Factors, Transcription, Genetic, Transcriptional Activation, Up-Regulation, Vascular Endothelial Growth Factor A metabolism, Hypoxia-Inducible Factor 1, alpha Subunit metabolism
- Abstract
Hypoxia-inducible factor-1 (HIF-1) is a key regulator of the cellular hypoxic response. We previously showed that HIF-1 activation is essential for heat acclimation (AC) in Caenorhabditis elegans. Metabolic changes in AC rat hearts indicate HIF-1alpha activation in mammals as well. Here we characterize the HIF-1alpha profile and the transcriptional activation of its target genes following AC and following heat stress (HS) in hearts from nonacclimated (C; 24 degrees C) and AC (34 degrees C, 1 mo) rats. We used Western blot and immunohistochemistry to measure HIF-1alpha levels and EMSA and RT-PCR/quantitative RT-PCR to detect expression of the HIF-1alpha-targeted genes, including vascular endothelial growth factor (Vegf), heme oxygenase-1 (HO1), erythropoietin (Epo), and Epo receptor (EpoR). EpoR and Epo mRNA levels were measured to determine systemic effects in the kidneys and cross-tolerance effects in C and AC ischemic hearts (Langendorff, 75% ischemia, 40 min). The results demonstrated that 1) after AC, HIF-1alpha protein levels were increased, 2) HS alone induced transient HIF-1alpha upregulation, and 3) VEGF and HO1 mRNA levels increased after HS, with greater magnitude in the AC hearts. Epo mRNA in AC kidneys and EpoR mRNA in AC hearts were also elevated. In AC hearts, EpoR expression was markedly higher after HS or ischemia. Hearts from AC rats were dramatically protected against infarction after ischemia-perfusion. We conclude that HIF-1 contributes to the acclimation-ischemia cross-tolerance mechanism in the heart by induction of both chronic and inducible adaptive components.
- Published
- 2005
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- View/download PDF
27. Stress-related genomic responses during the course of heat acclimation and its association with ischemic-reperfusion cross-tolerance.
- Author
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Horowitz M, Eli-Berchoer L, Wapinski I, Friedman N, and Kodesh E
- Subjects
- Animals, Heat Stress Disorders complications, Heat Stress Disorders immunology, Hot Temperature, Immunity, Innate immunology, Male, Rats, Reperfusion Injury complications, Reperfusion Injury immunology, Transcriptional Activation, Acclimatization, Gene Expression Regulation, Heat Stress Disorders physiopathology, Heat-Shock Proteins metabolism, Heat-Shock Response, Reperfusion Injury physiopathology
- Abstract
Acclimation to heat is a biphasic process involving a transient perturbed phase followed by a long lasting period during which acclimatory homeostasis is developed. In this investigation, we used cDNA stress microarray (Clontech Laboratory) to characterize the stress-related genomic response during the course of heat acclimation and to test the hypotheses that 1) heat acclimation influences the threshold of activation of protective molecular signaling, and 2) heat-acclimation-mediated ischemic-reperfusion (I/R) protection is coupled with reprogrammed gene expression leading to altered capacity or responsiveness of protective-signaling pathways shared by heat and I/R cytoprotective systems. Rats were acclimated at 34 degrees C for 0, 2, and 30 days. 32P-labeled RNA samples prepared from the left ventricles of rats before and after subjection to heat stress (HS; 2 h, 41 degrees C) or after I/R insult (ischemia: 75%, 45 min; reperfusion: 30 min) were hybridized onto the array membranes. Confirmatory RT-PCR of selected genes conducted on samples taken at 0, 30, and 60 min after HS or total ischemia was used to assess the promptness of the transcriptional response. Cluster analysis of the expressed genes indicated that acclimation involves a "two-tier" defense strategy: an immediate transient response peaking at the initial acclimating phase to maintain DNA and cellular integrity, and a sustained response, correlated with slowly developed adaptive, long-lasting cytoprotective signaling networks involving genes encoding proteins that are essential for the heat-shock response, antiapoptosis, and antioxidation. Gene activation was stress specific. Faster activation and suppression of signaling pathways shared by HS and I/R stressors probably contribute to heat-acclimation I/R cross-tolerance.
- Published
- 2004
- Full Text
- View/download PDF
28. Structural implications of the chemical modification of Cys(10) on actin.
- Author
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Eli-Berchoer L, Reisler E, and Muhlrad A
- Subjects
- Amino Acid Sequence, Animals, Binding Sites, Fluorescent Dyes, Macromolecular Substances, Microfilament Proteins metabolism, Models, Molecular, Muscle, Skeletal metabolism, Myosin Subfragments chemistry, Myosin Subfragments metabolism, Naphthalenesulfonates, Protein Structure, Secondary, Rabbits, Spectrometry, Fluorescence, Actins chemistry, Actins metabolism, Cysteine, Myosins chemistry, Myosins metabolism
- Abstract
Cys(10) is located in subdomain 1 of actin, which has an important role in the interaction of actin with myosin- and actin-binding proteins. Cys(10) was modified with fluorescence probes N-(iodoacetyl)N'-(5-sulfo-1-naphthyl)ethylene diamine (IAEDANS), 7-diethylamino-3-(4'-maleimidylphenyl)-4-methylcoumarin (CPM), or monobromo bimane (MBB) by the method of, J. Biol. Chem. 266:5508-5513). The specificity of Cys(10) modification was verified by showing that the 33-kDa subtilisin fragment of actin (residues 48-375), which contains all of the actin thiols but Cys(10), is not fluorescent. Cys(10) modification exposed a new site on actin to subtilisin cleavage. Edman degradation revealed this site to be between Ala(19) and Gly(20). The modification slightly increased the rate of epsilonATP-ATP exchange and decreased the rates of G-actin ATPase and polymerization. The activation of S1 ATPase by Cys(10)-modified F-actin showed small probe-dependent changes in the values of V(max) and K(M). The sliding speed of actin filaments in the in vitro motility assay remained unchanged upon modification of Cys(10). These results indicate that although the labeling of Cys(10) perturbs the structure of subdomain 1, the modified actin remains fully functional. The binding of S1 to actin filaments decreases the accessibility of Cys(10) probes to acrylamide and nitromethane quenchers. Because Cys(10) does not participate directly in either actin polymerization or S1 binding, our results indicate that actin-actin and actin-myosin interactions induce dynamic, allosteric changes in actin structure.
- Published
- 2000
- Full Text
- View/download PDF
29. Effect of intramolecular cross-linking between glutamine-41 and lysine-50 on actin structure and function.
- Author
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Eli-Berchoer L, Hegyi G, Patthy A, Reisler E, and Muhlrad A
- Subjects
- Actins chemistry, Actins drug effects, Adenosine Triphosphate metabolism, Animals, Binding Sites drug effects, Binding Sites physiology, Cell Movement drug effects, Cell Movement physiology, Deoxyribonuclease I chemistry, Deoxyribonuclease I drug effects, Deoxyribonuclease I metabolism, Glutamine chemistry, Lysine chemistry, Muscle Contraction drug effects, Muscle Contraction physiology, Myosins chemistry, Myosins drug effects, Myosins metabolism, Polymers metabolism, Protein Structure, Tertiary physiology, Rabbits, Subtilisins drug effects, Subtilisins metabolism, Transglutaminases pharmacology, Actins metabolism, Cross-Linking Reagents metabolism, Glutamine metabolism, Lysine metabolism
- Abstract
Subdomain 2 of actin is a dynamic segment of the molecule. The cross-linking of Gln-41 on subdomain 2 to Cys-374 on an adjacent monomer in F-actin inhibits actomyosin motility and force generation (Kim et al., 1998; Biochemistry 37, 17,801-17,809). To shed light on this effect, additional modifications of the Gln-41 site on actin were carried out. Both intact G-actin and G-actin cleaved by subtilisin between Met-47 and Gly-48 in the DNase 1 binding loop of subdomain 2 were treated with bacterial transglutaminase. According to the results of Edman degradation, transglutaminase introduced an intramolecular zero-length cross-linking between Gln-41 and Lys-50 in both intact and subtilisin cleaved actins. This cross-linking perturbs G-actin structure as shown by the inhibition of subtilisin and tryptic cleavage in subdomain 2, an allosteric inhibition of tryptic cleavage at the C-terminus and decrease of modification rate of Cys-374. The cross-linking increases while the subtilisin cleavage dramatically decreases the thermostability of F-actin. The Mg- and S1-induced polymerizations of both intact and subtilisin cleaved actins were only slightly influenced by the cross-linking. The activation of S1 ATPase by actin and the sliding speeds of actin filaments in the in vitro motility assays were essentially unchanged by the cross-linking. Thus, although intramolecular cross-linking between Gln-41 and Lys-50 perturbs the structure of the actin monomer, it has only a small effect on actin polymerization and its interaction with myosin. These results suggest that the new cross-linking does not alter the intermonomer interface in F-actin and that changes in actomyosin motility reported for the Gln-41-Cys-374 intrastrand cross-linked actin are not due to decreased flexibility of loop 38-52 but to constrains introduced into the F-actin structure and/or to perturbations at the actin's C-terminus.
- Published
- 2000
- Full Text
- View/download PDF
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