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Anacker A, Esser KH, Lenarz T, Paasche G. Purification of Fibroblasts From the Spiral Ganglion. Front Neurol 2022; 13:877342. [PMID: 35493807 PMCID: PMC9051338 DOI: 10.3389/fneur.2022.877342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 03/21/2022] [Indexed: 11/15/2022] Open
Abstract
Using cultures of freshly isolated spiral ganglion cells (SGC) is common to investigate the effect of substances on spiral ganglion neurons (SGN) in vitro. As these cultures contain more cell types than just neurons, and it might be beneficial to have cochlear fibroblasts available to further investigate approaches to reduce the growth of fibrous tissue around the electrode array after cochlear implantation, we aimed at the purification of fibroblasts from the spiral ganglion in the current study. Subcultivation of the primary SGC culture removed the neurons from the culture and increased the fibroblast to glial cell ratio in the preparations, which was revealed by staining for vimentin, the S100B-protein, and the 200-kD neurofilament. We performed direct immunolabeling for the Thy1-glycoprotein and the p75NGFR-enabled fluorescence-based cell sorting. This procedure resulted in a cell culture of cochlear fibroblasts with a purity of more than 99%. The received fibroblasts can be subcultivated for up to 10 passages before proliferation rates drop. Additionally, 80% of the cells survived the first attempt of cryopreservation and exhibited a fibroblast-specific morphology. Using the described approach provides a purified preparation of cochlear fibroblasts, which can now be used in vitro for further investigations.
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Affiliation(s)
- Annett Anacker
- Department of Otolaryngology, Hannover Medical School, Hannover, Germany
| | | | - Thomas Lenarz
- Department of Otolaryngology, Hannover Medical School, Hannover, Germany
- Cluster of Excellence Hearing4all, Hannover Medical School, Hannover, Germany
| | - Gerrit Paasche
- Department of Otolaryngology, Hannover Medical School, Hannover, Germany
- Cluster of Excellence Hearing4all, Hannover Medical School, Hannover, Germany
- *Correspondence: Gerrit Paasche
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Moon SK, Woo JI, Lim DJ. Involvement of TNF-α and IFN-γ in Inflammation-Mediated Cochlear Injury. Ann Otol Rhinol Laryngol 2019; 128:8S-15S. [DOI: 10.1177/0003489419837689] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Objectives: Inflammation is crucial for the pathogenesis of acquired sensorineural hearing loss, but the precise mechanism involved remains elusive. Among a number of inflammatory mediators, tumor necrosis factor-alpha (TNF-α) plays a pivotal role in cisplatin ototoxicity. However, TNF-α alone is cytotoxic to cochlear sensory cells only at the extremely high concentrations, suggesting the involvement of other factors that may sensitize cells to TNF-α cytotoxicity. Since interferon gamma (IFN-γ) importantly contributes to the cochlear inflammatory processes, we aim to determine whether and how IFN-γ affects TNF-α cytotoxicity to cochlear sensory cells. Methods: TNF-α expression was determined with western blotting in RSL cells and immunolabeling of mouse temporal bone sections. HEI-OC1 cell viability was determined with MTT assays, cytotoxicity assays, and cytometric analysis with methylene blue staining. Cochlear sensory cell injury was determined in the organotypic culture of the mouse organ of Corti. Results: Spiral ligament fibrocytes were shown to upregulate TNF-α in response to pro-inflammatory stimulants. We demonstrated IFN-γ increases the susceptibility of HEI-OC1 cells to TNF-α cytotoxicity via JAK1/2-STAT1 signaling. TNFR1-mediated Caspase-1 activation was found to mediate the sensitization effect of IFN-γ on TNF-α cytotoxicity. The combination of IFN-γ and TNF-α appeared to augment cisplatin cytotoxicity to cochlear sensory cells ex vivo. Conclusions: Taken together, these findings suggest the involvement of IFN-γ in the sensitization of cochlear cells to TNF-α cytotoxicity, which would enable us to better understand the complex mechanisms underlying inflammation-mediated cochlear injury.
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Affiliation(s)
- Sung K. Moon
- Department of Head and Neck Surgery, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - Jeong-Im Woo
- Department of Head and Neck Surgery, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - David J. Lim
- Department of Head and Neck Surgery, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
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Mwangi M, Kil SH, Phak D, Park HY, Lim DJ, Park R, Moon SK. Interleukin-10 Attenuates Hypochlorous Acid-Mediated Cytotoxicity to HEI-OC1 Cochlear Cells. Front Cell Neurosci 2017; 11:314. [PMID: 29056901 PMCID: PMC5635053 DOI: 10.3389/fncel.2017.00314] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 09/22/2017] [Indexed: 12/20/2022] Open
Abstract
Inflammatory reaction plays a crucial role in the pathophysiology of acquired hearing loss such as ototoxicity and labyrinthitis. In our earlier work, we showed the pivotal role of otic fibrocytes in cochlear inflammation and the critical involvement of proinflammatory cytokines in cisplatin ototoxicity. We also demonstrated that otic fibrocytes inhibit monocyte chemoattractant protein 1 (CCL2) upregulation in response to interleukin-10 (IL-10) via heme oxygenase 1 (HMOX1) signaling, resulting in suppression of cochlear inflammation. However, it is still unclear how IL-10 affects inflammation-mediated cochlear injury. Here we aim to determine how hypochlorous acid, a model inflammation mediator affects cochlear cell viability and how IL-10 affects hypochlorous acid-mediated cochlear cell injury. NaOCl, a sodium salt of hypochlorous acid (HOCl) was found to induce cytotoxicity of HEI-OC1 cells in a dose-dependent manner. Combination of hydrogen peroxide and myeloperoxidase augmented cisplatin cytotoxicity, and this synergism was inhibited by N-Acetyl-L-cysteine and ML-171. The rat spiral ligament cell line (RSL) appeared to upregulate the antioxidant response element (ARE) activities upon exposure to IL-10. RSL cells upregulated the expression of NRF2 (an ARE ligand) and NR0B2 in response to CoPP (a HMOX1 inducer), but not to ZnPP (a HMOX1 inhibitor). Adenovirus-mediated overexpression of NR0B2 was found to suppress CCL2 upregulation. IL-10-positive cells appeared in the mouse stria vascularis 1 day after intraperitoneal injection of lipopolysaccharide (LPS). Five days after injection, IL-10-positive cells were observed in the spiral ligament, spiral limbus, spiral ganglia, and suprastrial area, but not in the stria vascularis. IL-10R1 appeared to be expressed in the mouse organ of Corti as well as HEI-OC1 cells. HEI-OC1 cells upregulated Bcl-xL expression in response to IL-10, and IL-10 was shown to attenuate NaOCl-induced cytotoxicity. In addition, HEI-OC1 cells upregulated IL-22RA upon exposure to cisplatin, and NaOCl cytotoxicity was inhibited by IL-22. Taken together, our findings suggest that hypochlorous acid is involved in cochlear injury and that IL-10 potentially reduces cochlear injury through not only inhibition of inflammation but also enhancement of cochlear cell viability. Further studies are needed to determine immunological characteristics of intracochlear IL-10-positive cells and elucidate molecular mechanisms involved in the otoprotective activity of IL-10.
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Affiliation(s)
- Martin Mwangi
- Department of Head and Neck Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Sung-Hee Kil
- Department of Head and Neck Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - David Phak
- Department of Head and Neck Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Hun Yi Park
- Department of Otolaryngology, Ajou University School of Medicine, Suwon, South Korea
| | - David J Lim
- Department of Head and Neck Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Raekil Park
- Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Sung K Moon
- Department of Head and Neck Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
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Woo JI, Kil SH, Oh S, Lee YJ, Park R, Lim DJ, Moon SK. IL-10/HMOX1 signaling modulates cochlear inflammation via negative regulation of MCP-1/CCL2 expression in cochlear fibrocytes. THE JOURNAL OF IMMUNOLOGY 2015; 194:3953-61. [PMID: 25780042 DOI: 10.4049/jimmunol.1402751] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 02/16/2015] [Indexed: 12/19/2022]
Abstract
Cochlear inflammatory diseases, such as tympanogenic labyrinthitis, are associated with acquired sensorineural hearing loss. Although otitis media is extremely frequent in children, tympanogenic labyrinthitis is not commonly observed, which suggests the existence of a potent anti-inflammatory mechanism modulating cochlear inflammation. In this study, we aimed to determine the molecular mechanism involved in cochlear protection from inflammation-mediated tissue damage, focusing on IL-10 and hemoxygenase-1 (HMOX1) signaling. We demonstrated that IL-10Rs are expressed in the cochlear lateral wall of mice and rats, particularly in the spiral ligament fibrocytes (SLFs). The rat SLF cell line was found to inhibit nontypeable Haemophilus influenzae (NTHi)-induced upregulation of monocyte chemotactic protein-1 (MCP-1; CCL2) in response to IL-10. This inhibition was suppressed by silencing IL-10R1 and was mimicked by cobalt Protoporphyrin IX and CO-releasing molecule-2. In addition, IL-10 appeared to suppress monocyte recruitment through reduction of NTHi-induced rat SLF cell line-derived chemoattractants. Silencing of HMOX1 was found to attenuate the inhibitory effect of IL-10 on NTHi-induced MCP-1/CCL2 upregulation. Chromatin immunoprecipitation assays showed that IL-10 inhibits NTHi-induced binding of p65 NF-κB to the distal motif in the promoter region of MCP-1/CCL2, resulting in suppression of NTHi-induced NF-κB activation. Furthermore, IL-10 deficiency appeared to significantly affect cochlear inflammation induced by intratympanic injections of NTHi. Taken together, our results suggest that IL-10/HMOX1 signaling is involved in modulation of cochlear inflammation through inhibition of MCP-1/CCL2 regulation in SLFs, implying a therapeutic potential for a CO-based approach for inflammation-associated cochlear diseases.
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Affiliation(s)
- Jeong-Im Woo
- Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095
| | - Sung-Hee Kil
- Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095
| | - Sejo Oh
- Division of Clinical and Translational Research, House Research Institute, Los Angeles, CA 90057; and
| | - Yoo-Jin Lee
- Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095
| | - Raekil Park
- Department of Microbiology and Center for Metabolic Function Regulation, Wonkwang University School of Medicine, Iksan, Jeonbuk 570-749, South Korea
| | - David J Lim
- Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095
| | - Sung K Moon
- Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095;
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Sun GW, Fujii M, Matsunaga T. Functional interaction between mesenchymal stem cells and spiral ligament fibrocytes. J Neurosci Res 2012; 90:1713-22. [DOI: 10.1002/jnr.23067] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Revised: 03/03/2012] [Accepted: 03/20/2012] [Indexed: 01/15/2023]
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Oh S, Woo JI, Lim DJ, Moon SK. ERK2-dependent activation of c-Jun is required for nontypeable Haemophilus influenzae-induced CXCL2 upregulation in inner ear fibrocytes. THE JOURNAL OF IMMUNOLOGY 2012; 188:3496-505. [PMID: 22379036 DOI: 10.4049/jimmunol.1103182] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The inner ear, composed of the cochlea and the vestibule, is a specialized sensory organ for hearing and balance. Although the inner ear has been known as an immune-privileged organ, there is emerging evidence indicating an active immune reaction of the inner ear. Inner ear inflammation can be induced by the entry of proinflammatory molecules derived from middle ear infection. Because middle ear infection is highly prevalent in children, middle ear infection-induced inner ear inflammation can impact the normal development of language and motor coordination. Previously, we have demonstrated that the inner ear fibrocytes (spiral ligament fibrocytes) are able to recognize nontypeable Haemophilus influenzae, a major pathogen of middle ear infection, and upregulate a monocyte-attracting chemokine through TLR2-dependent NF-κB activation. In this study, we aimed to determine the molecular mechanism involved in nontypeable H. influenzae-induced cochlear infiltration of polymorphonuclear cells. The rat spiral ligament fibrocytes were found to release CXCL2 in response to nontypeable H. influenzae via activation of c-Jun, leading to the recruitment of polymorphonuclear cells to the cochlea. We also demonstrate that MEK1/ERK2 signaling pathway is required for nontypeable H. influenzae-induced CXCL2 upregulation in the rat spiral ligament fibrocytes. Two AP-1 motifs in the 5'-flanking region of CXCL2 appeared to function as a nontypeable H. influenzae-responsive element, and the proximal AP-1 motif was found to have a higher binding affinity to nontypeable H. influenzae-activated c-Jun than that of the distal one. Our results will enable us better to understand the molecular pathogenesis of middle ear infection-induced inner ear inflammation.
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Affiliation(s)
- Sejo Oh
- Division of Clinical and Translational Research, House Research Institute, Los Angeles, CA 90057, USA
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Spiral ligament fibrocyte-derived MCP-1/CCL2 contributes to inner ear inflammation secondary to nontypeable H. influenzae-induced otitis media. BMC Infect Dis 2010; 10:314. [PMID: 21029462 PMCID: PMC2988798 DOI: 10.1186/1471-2334-10-314] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Accepted: 10/28/2010] [Indexed: 12/20/2022] Open
Abstract
Background Otitis media (OM), one of the most common pediatric infectious diseases, causes inner ear inflammation resulting in vertigo and sensorineural hearing loss. Previously, we showed that spiral ligament fibrocytes (SLFs) recognize OM pathogens and up-regulate chemokines. Here, we aim to determine a key molecule derived from SLFs, contributing to OM-induced inner ear inflammation. Methods Live NTHI was injected into the murine middle ear through the tympanic membrane, and histological analysis was performed after harvesting the temporal bones. Migration assays were conducted using the conditioned medium of NTHI-exposed SLFs with and without inhibition of MCP-1/CCL2 and CCR2. qRT-PCR analysis was performed to demonstrate a compensatory up-regulation of alternative genes induced by the targeting of MCP-1/CCL2 or CCR2. Results Transtympanic inoculation of live NTHI developed serous and purulent labyrinthitis after clearance of OM. THP-1 cells actively migrated and invaded the extracellular matrix in response to the conditioned medium of NTHI-exposed SLFs. This migratory activity was markedly inhibited by the viral CC chemokine inhibitor and the deficiency of MCP-1/CCL2, indicating that MCP-1/CCL2 is a main attractant of THP-1 cells among the SLF-derived molecules. We further demonstrated that CCR2 deficiency inhibits migration of monocyte-like cells in response to NTHI-induced SLF-derived molecules. Immunolabeling showed an increase in MCP-1/CCL2 expression in the cochlear lateral wall of the NTHI-inoculated group. Contrary to the in vitro data, deficiency of MCP-1/CCL2 or CCR2 did not inhibit OM-induced inner ear inflammation in vivo. We demonstrated that targeting MCP-1/CCL2 enhances NTHI-induced up-regulation of MCP-2/CCL8 in SLFs and up-regulates the basal expression of CCR2 in the splenocytes. We also found that targeting CCR2 enhances NTHI-induced up-regulation of MCP-1/CCL2 in SLFs. Conclusions Taken together, we suggest that NTHI-induced SLF-derived MCP-1/CCL2 is a key molecule contributing to inner ear inflammation through CCR2-mediated recruitment of monocytes. However, deficiency of MCP-1/CCL2 or CCR2 alone was limited to inhibit OM-induced inner ear inflammation due to compensation of alternative genes.
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Moon SK, Woo JI, Lee HY, Park R, Shimada J, Pan H, Gellibolian R, Lim DJ. Toll-like receptor 2-dependent NF-kappaB activation is involved in nontypeable Haemophilus influenzae-induced monocyte chemotactic protein 1 up-regulation in the spiral ligament fibrocytes of the inner ear. Infect Immun 2007; 75:3361-72. [PMID: 17452470 PMCID: PMC1932924 DOI: 10.1128/iai.01886-06] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Inner ear dysfunction secondary to chronic otitis media (OM), including high-frequency sensorineural hearing loss or vertigo, is not uncommon. Although chronic middle ear inflammation is believed to cause inner ear dysfunction by entry of OM pathogen components or cytokines from the middle ear into the inner ear, the underlying mechanisms are not well understood. Previously, we demonstrated that the spiral ligament fibrocyte (SLF) cell line up-regulates monocyte chemotactic protein 1 (MCP-1) expression after treatment with nontypeable Haemophilus influenzae (NTHI), one of the most common OM pathogens. We hypothesized that the SLF-derived MCP-1 plays a role in inner ear inflammation secondary to OM that is responsible for hearing loss and dizziness. The purpose of this study was to investigate the signaling pathway involved in NTHI-induced MCP-1 up-regulation in SLFs. Here we show for the first time that NTHI induces MCP-1 up-regulation in the SLFs via Toll-like receptor 2 (TLR2)-dependent activation of NF-kappaB. TLR2(-/-)- and MyD88(-/-)-derived SLFs revealed involvement of TLR2 and MyD88 in NTHI-induced MCP-1 up-regulation. Studies using chemical inhibitors and dominant-negative constructs demonstrated that it is mediated by the IkappaKbeta-dependent IkappaBalpha phosphorylation and NTHI-induced NF-kappaB nuclear translocation. Furthermore, we demonstrated that the binding of NF-kappaB to the enhancer region of MCP-1 is involved in this up-regulation. In addition, we have identified a potential NF-kappaB motif that is responsive and specific to certain NTHI molecules or ligands. Further studies are necessary to reveal specific ligands of NTHI that activate host receptors. These results may provide us with new therapeutic strategies for prevention of inner ear dysfunction secondary to chronic middle ear inflammation.
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Affiliation(s)
- Sung K Moon
- The Gonda Department of Cell and Molecular Biology, House Ear Institute, 2100 West 3rd Street, Los Angeles, CA 90057, USA
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