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Kaya S, Paparella MM, Cureoglu S. Does Otosclerosis Affect Dark and Transitional Cells in the Human Vestibular Labyrinth? Otol Neurotol 2017; 38:234-238. [PMID: 27851656 DOI: 10.1097/mao.0000000000001272] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
HYPOTHESIS The density of vestibular dark cells (DCs) and vestibular transitional cells (TCs) can be quantitatively decreased in human temporal bones with otosclerosis. BACKGROUND Previous reports have shown that otosclerosis can lead to vestibular symptoms. METHODS We examined 61 human temporal bone specimens from 52 deceased donors with otosclerosis group-with and without endosteal involvement (EI), and with and without endolymphatic hydrops (EH)-versus 25 specimens from 18 age-matched controls. Using light microscopy, we evaluated the nonsensory epithelium of the lateral semicircular canal (LSC) and posterior semicircular canal (PSC) of the human vestibular labyrinth, focusing on the density of DCs and TCs. RESULTS In both the LSC and the PSC, as compared with the control group, the mean density of DCs significantly decreased in the EI (+) group, in the EI (+) and EH (+) subgroup, and in the EI (+) and EH (-) subgroup (p < 0.05). In addition, we found a significant difference in the mean density of DCs between the EI (+) group and the EI (-) group in the LSC and in the PSC (p < 0.05). But we found no significant difference in the mean density of TCs in any of the otosclerosis groups or subgroups as compared with the control group (p > 0.05). CONCLUSION We found a decrease in the density of DCs associated with EI in human temporal bone specimens with otosclerosis, regardless of the presence of EH. This decrease might cause damage in ion and water transportation, leading to vestibular symptoms.
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Affiliation(s)
- Serdar Kaya
- *Department of Otolaryngology, University of Minnesota, Minneapolis, Minnesota, U.S.A. †Department of Otolaryngology-Head and Neck Surgery, Gebze Fatih State Hospital, Gebze, Kocaeli, Turkey ‡Paparella Ear Head & Neck Institute, Minneapolis, Minnesota, U.S.A
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Uetsuka S, Ogata G, Nagamori S, Isozumi N, Nin F, Yoshida T, Komune S, Kitahara T, Kikkawa Y, Inohara H, Kanai Y, Hibino H. Molecular architecture of the stria vascularis membrane transport system, which is essential for physiological functions of the mammalian cochlea. Eur J Neurosci 2015; 42:1984-2002. [PMID: 26060893 DOI: 10.1111/ejn.12973] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 06/02/2015] [Accepted: 06/02/2015] [Indexed: 11/29/2022]
Abstract
Stria vascularis of the mammalian cochlea transports K(+) to establish the electrochemical property in the endolymph crucial for hearing. This epithelial tissue also transports various small molecules. To clarify the profile of proteins participating in the transport system in the stria vascularis, membrane components purified from the stria of adult rats were analysed by liquid chromatography tandem mass spectrometry. Of the 3236 proteins detected in the analysis, 1807 were membrane proteins. Ingenuity Knowledge Base and literature data identified 513 proteins as being expressed on the 'plasma membrane', these included 25 ion channels and 79 transporters. Sixteen of the former and 62 of the latter had not yet been identified in the stria. Unexpectedly, many Cl(-) and Ca(2+) transport systems were found, suggesting that the dynamics of these ions play multiple roles. Several transporters for organic substances were also detected. Network analysis demonstrated that a few kinases, including protein kinase A, and Ca(2+) were key regulators for the strial transports. In the library of channels and transporters, 19 new candidates for uncloned deafness-related genes were identified. These resources provide a platform for understanding the molecular mechanisms underlying the epithelial transport essential for cochlear function and the pathophysiological processes involved in hearing disorders.
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Affiliation(s)
- Satoru Uetsuka
- Department of Molecular Physiology, Niigata University School of Medicine, 1-757 Asahimachi-dori, Niigata, 951-8510, Japan.,Center for Transdisciplinary Research, Niigata University, Niigata, Japan.,Department of Otorhinolaryngology - Head and Neck Surgery, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Genki Ogata
- Department of Molecular Physiology, Niigata University School of Medicine, 1-757 Asahimachi-dori, Niigata, 951-8510, Japan.,Center for Transdisciplinary Research, Niigata University, Niigata, Japan
| | - Shushi Nagamori
- Division of Bio-system Pharmacology, Department of Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Noriyoshi Isozumi
- Division of Bio-system Pharmacology, Department of Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Fumiaki Nin
- Department of Molecular Physiology, Niigata University School of Medicine, 1-757 Asahimachi-dori, Niigata, 951-8510, Japan.,Center for Transdisciplinary Research, Niigata University, Niigata, Japan
| | - Takamasa Yoshida
- Department of Molecular Physiology, Niigata University School of Medicine, 1-757 Asahimachi-dori, Niigata, 951-8510, Japan.,Center for Transdisciplinary Research, Niigata University, Niigata, Japan.,Department of Otorhinolaryngology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Shizuo Komune
- Department of Otorhinolaryngology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Tadashi Kitahara
- Department of Otorhinolaryngology - Head and Neck Surgery, Graduate School of Medicine, Osaka University, Osaka, Japan.,Department of Otorhinolaryngology - Head and Neck Surgery, Nara Medical University, Nara, Japan
| | - Yoshiaki Kikkawa
- Mammalian Genetics Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Hidenori Inohara
- Department of Otorhinolaryngology - Head and Neck Surgery, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Yoshikatsu Kanai
- Division of Bio-system Pharmacology, Department of Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Hiroshi Hibino
- Department of Molecular Physiology, Niigata University School of Medicine, 1-757 Asahimachi-dori, Niigata, 951-8510, Japan.,Center for Transdisciplinary Research, Niigata University, Niigata, Japan
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Abstract
BACKGROUND The pathologic changes that occur as a result of diabetic microangiopathy have been well described for the kidneys and the eyes. Although many studies suggest an association between diabetes mellitus and hearing loss, the pathologic changes in the cochlea in association with the diabetic state remain to be clarified. AIM/OBJECTIVE The aim of this review is to determine the effects of diabetes mellitus on cochlear morphology. METHOD A comprehensive search for relevant articles was carried out on electronic databases of Ovid Medline, Ovid Medline in Process, PubMed, Ovid Embase,or Biosis Preview, The Cochrane Library, ISI Web of Science, and Scopus. Articles published in English between 1940 and June 2010 were eligible to be reviewed. Using predefined inclusion criteria, published articles on histologic changes occurring in the cochlea due to diabetes mellitus were selected and reviewed, and their findings were synthesized. RESULTS Changes were observed in the basement membrane of the capillaries of the stria vascularis and in the basilar membrane, which was remarkably thickened, giving rise to diabetic microangiopathy. Loss of spiral ganglion neurons, organ of Corti cells, and atrophic changes in the stria vascularis were varied and infrequent. CONCLUSION There seems to be variable vulnerability of different cochlear cell types to the DM state. Further studies are required to determine the factors responsible for the differences in the histopathologic observations of cochlear tissues.
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Cura AJ, Carruthers A. Role of monosaccharide transport proteins in carbohydrate assimilation, distribution, metabolism, and homeostasis. Compr Physiol 2013; 2:863-914. [PMID: 22943001 DOI: 10.1002/cphy.c110024] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The facilitated diffusion of glucose, galactose, fructose, urate, myoinositol, and dehydroascorbicacid in mammals is catalyzed by a family of 14 monosaccharide transport proteins called GLUTs. These transporters may be divided into three classes according to sequence similarity and function/substrate specificity. GLUT1 appears to be highly expressed in glycolytically active cells and has been coopted in vitamin C auxotrophs to maintain the redox state of the blood through transport of dehydroascorbate. Several GLUTs are definitive glucose/galactose transporters, GLUT2 and GLUT5 are physiologically important fructose transporters, GLUT9 appears to be a urate transporter while GLUT13 is a proton/myoinositol cotransporter. The physiologic substrates of some GLUTs remain to be established. The GLUTs are expressed in a tissue specific manner where affinity, specificity, and capacity for substrate transport are paramount for tissue function. Although great strides have been made in characterizing GLUT-catalyzed monosaccharide transport and mapping GLUT membrane topography and determinants of substrate specificity, a unifying model for GLUT structure and function remains elusive. The GLUTs play a major role in carbohydrate homeostasis and the redistribution of sugar-derived carbons among the various organ systems. This is accomplished through a multiplicity of GLUT-dependent glucose sensing and effector mechanisms that regulate monosaccharide ingestion, absorption,distribution, cellular transport and metabolism, and recovery/retention. Glucose transport and metabolism have coevolved in mammals to support cerebral glucose utilization.
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Affiliation(s)
- Anthony J Cura
- Department of Biochemistry & Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
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5
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Mazurek B, Amarjargal N, Haupt H, Fuchs J, Olze H, Machulik A, Gross J. Expression of genes implicated in oxidative stress in the cochlea of newborn rats. Hear Res 2011; 277:54-60. [PMID: 21447374 DOI: 10.1016/j.heares.2011.03.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Revised: 03/16/2011] [Accepted: 03/17/2011] [Indexed: 01/03/2023]
Abstract
Oxidative stress is an important mechanism inducing ototoxicity-, age- and noise-induced hearing loss. To better understand this phenomenon, we examined cochlear tissues for the expression of following genes involved directly or indirectly in the oxidative stress response: glyceraldehyde-3-phosphate dehydrogenase (Gapdh); solute carrier family-2 (facilitated glucose transporter), member-1 (Slc2a1); heme oxygenase-1 (Hmox1); heme oxygenase-2 (Hmox2); inducible nitric oxide synthase-2 (Nos2); transferrin (Tf); transferrin receptor (Tfrc); glutathione S-transferase A3 (Gsta3) and metallothionein-1a (Mt1a). Cochlear tissues were dissected from the p3-p5 Wistar rats, divided into the organ of Corti (OC), modiolus (MOD) and stria vascularis together with spiral ligament (SV + SL) and processed immediately or cultured under normoxic conditions or a short-term, mild hypoxia followed by re-oxygenation. After 24 h, explants were collected and total RNA isolated, transcribed and amplified in the real time RT-PCR. We found all genes listed above expressed in the freshly isolated cochlear tissues. In the OC and MOD, Slc2a1, Tf, and Mt1a were expressed on a lower level than in the SV + SL. In the OC, Hmox1 was expressed on a lower level than in the MOD and SV + SL. Hypoxic and normoxic cultures increased the transcript number of Gapdh, Slc2a1 and Hmox1 in all cochlear tissues. The expression of Nos2, Tf, Gsta3 and Mt1a increased in a tissue-specific manner. In the SV + SL, Mt1a expression decreased after normoxic and hypoxic conditions. Taken together, using real time RT-PCR, our results imply that oxidative stress may be an important component of cochlear injury during the developing period. In spite of the immaturity of the tissue, a differential response of antioxidant enzymes/proteins with respect to the pathway, the expression levels and regions was observed.
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Affiliation(s)
- Birgit Mazurek
- Molecular Biology Research Laboratory, Department of Otorhinolaryngology CCM, Charité-Universitätsmedizin Berlin, Berlin, Germany.
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Edamatsu M, Kondo Y, Ando M. Multiple expression of glucose transporters in the lateral wall of the cochlear duct studied by quantitative real-time PCR assay. Neurosci Lett 2010; 490:72-7. [PMID: 21182893 DOI: 10.1016/j.neulet.2010.12.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Revised: 12/02/2010] [Accepted: 12/11/2010] [Indexed: 11/20/2022]
Abstract
We have investigated the gene expression of the facilitated glucose transporter (GLUT), H+-coupled myo-inositol cotransporter (HMIT), and Na+ glucose cotransporter (SGLT) in the lateral wall of the cochlear duct by conventional RT-PCR and quantitative real-time PCR. The isoforms GLUT1, -3, -4, -5, -8, -10, -12 and HMIT were detected in both the stria vascularis and the spiral ligament, whereas no SGLT isoforms could be detected in these tissues. Quantitative real-time PCR analysis revealed significant differences in the gene expression of GLUT1, -4, -5, -10, and HMIT isoforms between the stria vascularis and the spiral ligament. This result reflects the tissue-dependent distributions of GLUT isoforms. These findings strongly suggest that a number of GLUT isoforms participate in glucose transport in the stria vascularis and the spiral ligament.
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Affiliation(s)
- Midori Edamatsu
- Laboratory of Cell Physiology, Department of Science Education, Graduate School of Education, Okayama University, Okayama 700-8530, Japan
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Roles of gap junctions in glucose transport from glucose transporter 1-positive to -negative cells in the lateral wall of the rat cochlea. Histochem Cell Biol 2008; 131:89-102. [PMID: 18787834 DOI: 10.1007/s00418-008-0502-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/26/2008] [Indexed: 01/23/2023]
Abstract
Despite the importance of glucose metabolism for auditory function, the mechanisms of glucose transport in the cochlea are not completely understood. We hypothesized that gap junctions mediate intercellular glucose transport in the cochlea in cooperation with facilitative glucose transporter 1 (GLUT1). Immunohistochemistry showed that GLUT1 and the tight junction protein occludin were expressed in blood vessels, and GLUT1, the gap junction proteins connexin26 and connexin30, and occludin were also present in strial basal cells in the lateral wall of the rat cochlea. Gap junctions were found among not only these GLUT1-positive strial basal cells but also GLUT1-negative fibrocytes in the spiral ligaments and strial intermediate cells. Glucose imaging using 6-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-6-deoxyglucose (6-NBDG, MW 342) together with Evans Blue Albumin (EBA, MW 68,000) showed that 6-NBDG was rapidly distributed throughout the stria vascularis and spiral ligament, whereas EBA was localized only in the vessels. The gap junctional uncouplers heptanol and carbenoxolone inhibited the distribution of 6-NBDG in the spiral ligament without decreasing the fluorescence of EBA in the blood vessels. These findings suggest that gap junctions mediate glucose transport from GLUT1-positive cells (strial basal cells) to GLUT1-negative cells (fibrocytes in the spiral ligament and strial intermediate cells) in the cochlea.
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8
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Stria vascularis and vestibular dark cells: characterisation of main structures responsible for inner-ear homeostasis, and their pathophysiological relations. The Journal of Laryngology & Otology 2008; 123:151-62. [DOI: 10.1017/s0022215108002624] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractThe regulation of inner-ear fluid homeostasis, with its parameters volume, concentration, osmolarity and pressure, is the basis for adequate response to stimulation. Many structures are involved in the complex process of inner-ear homeostasis. The stria vascularis and vestibular dark cells are the two main structures responsible for endolymph secretion, and possess many similarities. The characteristics of these structures are the basis for regulation of inner-ear homeostasis, while impaired function is related to various diseases. Their distinct morphology and function are described, and related to current knowledge of associated inner-ear diseases. Further research on the distinct function and regulation of these structures is necessary in order to develop future clinical interventions.
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Cellular localization of facilitated glucose transporter 1 (GLUT-1) in the cochlear stria vascularis: its possible contribution to the transcellular glucose pathway. Cell Tissue Res 2008; 331:763-9. [PMID: 18196278 DOI: 10.1007/s00441-007-0495-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2007] [Accepted: 08/02/2007] [Indexed: 10/22/2022]
Abstract
Immunoreactivity for the facilitated glucose transporter 1 (GLUT-1) has been found in the cochlear stria vascularis, but whether the strial marginal cells are immunopositive for GLUT-1 remains uncertain. To determine the cellular localization of GLUT-1 and to clarify the glucose pathway in the stria vascularis of rats and guinea pigs, immunohistochemistry was performed on sections, dissociated cells, and whole-tissue preparations. Immunoreactivity for GLUT-1 in sections was observed in the basal side of the strial tissue and in capillaries in both rats and guinea pigs. However, the distribution of the positive signals within the guinea pig strial tissue was more diffuse than that in rats. Immunostaining of dissociated guinea pig strial cells revealed GLUT-1 in the basal cells and capillary endothelial cells, but not in the marginal cells. These results indicated that GLUT-1 was not expressed in the marginal cells, and that another isoform of GLUT was probably expressed in these cells. Three-dimensional observation of whole-tissue preparations demonstrated that cytoplasmic prolongations from basal cells extended upward to the apical surface of the stria vascularis from rats and guinea pigs, and that the marginal cells were surrounded by these protrusions. We speculate that these upward extensions of basal cells have been interpreted as basal infoldings of marginal cells in previous reports from other groups. The three-dimensional relationship between marginal cells and basal cells might contribute to the transcellular glucose pathway from perilymph to intrastrial space.
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Davey KAB, Garlick PB, Warley A, Southworth R. Immunogold labeling study of the distribution of GLUT-1 and GLUT-4 in cardiac tissue following stimulation by insulin or ischemia. Am J Physiol Heart Circ Physiol 2006; 292:H2009-19. [PMID: 17189352 DOI: 10.1152/ajpheart.00663.2006] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Whereas glucose transporter 1 (GLUT-1) is thought to be responsible for basal glucose uptake in cardiac myocytes, little is known about its relative distribution between the different plasma membranes and cell types in the heart. GLUT-4 translocates to the myocyte surface to increase glucose uptake in response to a number of stimuli. The mechanisms underlying ischemia- and insulin-mediated GLUT-4 translocation are known to be different, raising the possibility that the intracellular destinations of GLUT-4 following these stimuli also differ. Using immunogold labeling, we describe the cellular localization of these two transporters and investigate whether insulin and ischemia induce differential translocation of GLUT-4 to different cardiac membranes. Immunogold labeling of GLUT-1 and GLUT-4 was performed on left ventricular sections from isolated hearts following 30 min of either insulin, ischemia, or control perfusion. In control tissue, GLUT-1 was predominantly (76%) localized in the capillary endothelial cells, with only 24% of total cardiac GLUT-1 present in myocytes. GLUT-4 was found predominantly in myocytes, distributed between sarcolemmal and T tubule membranes (1.84 +/- 0.49 and 1.54 +/- 0.33 golds/microm, respectively) and intracellular vesicles (127 +/- 18 golds/microm(2)). Insulin increased T tubule membrane GLUT-4 content (2.8 +/- 0.4 golds/microm, P < 0.05) but had less effect on sarcolemmal GLUT-4 (1.72 +/- 0.53 golds/microm). Ischemia induced greater GLUT-4 translocation to both membrane types (4.25 +/- 0.84 and 4.01 +/- 0.27 golds/microm, respectively P < 0.05). The localization of GLUT-1 suggests a significant role in transporting glucose across the capillary wall before myocyte uptake via GLUT-1 and GLUT-4. We demonstrate independent spatial translocation of GLUT-4 under insulin or ischemic stimulation and propose independent roles for T-tubular and sarcolemmal GLUT-4.
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Affiliation(s)
- Katherine A B Davey
- Division of Imaging Sciences, Guy's, King's, and St. Thomas' School of Medicine, King's College London, London, United Kingdom
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De Silva MG, Hildebrand MS, Christopoulos H, Newman MR, Bell K, Ritchie M, Smyth GK, Dahl HHM. Gene expression changes during step-wise differentiation of embryonic stem cells along the inner ear hair cell pathway. Acta Otolaryngol 2006; 126:1148-57. [PMID: 17050306 DOI: 10.1080/00016480600702118] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
CONCLUSION Our study outlines an alternative approach for the selection and investigation of genes involved in inner ear function. OBJECTIVE To gain understanding of the gene pathways involved in the development of the normal cochlea. MATERIALS AND METHODS Microarray technology currently offers the most efficient approach to investigate gene expression and identify pathways involved in cell differentiation. Epidermal growth factor (EGF) induces cultures derived from the organ of Corti to proliferate and produce new hair cells. Since pluripotent embryonic stem (ES) cells have the capacity to generate all tissues, we induced murine ES cells to differentiate towards ectodermal and neuroectodermal cell types and from there investigated their commitment towards the hair cell lineage in the presence of EGF. Cells were collected at three points along the differentiation pathway and their expression profiles were determined using the Soares NMIE mouse inner ear cDNA library printed in microarray format. RESULTS Three genes up-regulated after addition of EGF (serine (or cysteine) proteinase inhibitor, clade H, member 1 (Serpinh1), solute carrier family 2 (facilitated glucose transporter), member 10 (Slc2a10) and secreted acidic cysteine-rich glycoprotein (Sparc)) were selected for further analysis and characterization. Of the three genes, Serpinh1 and Slc2a10 have never been implicated in the hearing process.
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Affiliation(s)
- Michelle G De Silva
- Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Vic 3052, Australia.
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Mazurek B, Rheinländer C, Fuchs FU, Amarjargal N, Kuban RJ, Ungethüm U, Haupt H, Kietzmann T, Gross J. Einfluss von Ischämie/Hypoxie auf die HIF-1-Aktivität und Expression von hypoxieabhängigen Genen in der Kochlea der neugeborenen Ratte. HNO 2006; 54:689-97. [PMID: 16479386 DOI: 10.1007/s00106-005-1371-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND Transcription factor HIF-1 (hypoxia-inducible factor-1) regulates the expression of genes which are involved in glucose supply, growth, metabolism, redox reactions and blood supply. Hypoxia and ischemia play an important role in the pathogenesis of tinnitus and hearing loss. Therefore, HIF-1 activity and the expression of HIF-1 dependent genes in the cochlea were examined under ischemic and hypoxic conditions. MATERIAL AND METHODS For the HIF-1 analysis, single-cell cultures of the organ of Corti (OC), stria vascularis (SV) and modiolus (MOD) were used. mRNA expression was analyzed in the organotypic culture using a microarray technique (RN U34-chip, Affymetrix). RESULTS Ischemia (hypoxia without glucose) and pure hypoxia increase the HIF-1 activity identically, with the highest increase found in MOD and OC. The HIF-1 alpha mRNA levels were found to be higher in SV than in the OC and MOD. During culturing, there is a clear increase in HIF-1 alpha mRNA and the expression of a number of HIF-1 dependent genes, such as Gapdh/glyceraldehyde-3-phosphate dehydrogenase, Slc2a1/solute carrier family 2 (facilitated glucose transporter), member 1, Tf/transferrin and Tfrc/transferrin receptor, in all three regions. In SV, MOD and OC, increase in the expression of Hmox1/hemoxygenase 1, Nos2/nitric oxide synthase, inducible and Tfrc is particularly high. Hypoxia (5 h) results in an increased expression of Igf2/Insulin-like growth factor 2. CONCLUSION The present data underline the contribution of radical forming processes to the pathogenesis of inner ear diseases. For experimental research, it is important to note that organotypic culture may be coupled with hypoxia.
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Affiliation(s)
- B Mazurek
- Molekularbiologisches Forschungslabor der HNO-Klinik, Charité--Universitätsmedizin Berlin
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Bittar RSM, Bottino MA, Simoceli L, Venosa AR. Labirintopatia secundária aos distúrbios do metabolismo do açúcar: realidade ou fantasia? ACTA ACUST UNITED AC 2004. [DOI: 10.1590/s0034-72992004000600016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
As vestibulopatias atribuídas aos distúrbios do metabolismo do açúcar são ainda hoje um tema controverso na literatura pela falta de demonstração objetiva que relacione causa e efeito. OBJETIVO: Nosso objetivo é relatar os resultados seriados do Teste de Integração Sensorial no acompanhamento dos pacientes portadores de DMA tratados com dieta fracionada e restrição de glicose. FORMA DE ESTUDO: Retrospectivo, inclui um desenho de descrição de casos. MÉTODO: Foram avaliadas as respostas de 21 pacientes portadores de distúrbios do metabolismo do açúcar e tontura submetidos à dieta fracionada com restrição de glicose. A medição objetiva do equilíbrio corporal dos pacientes foi feita pela Posturografia Dinâmica Computadorizada, utilizando-se o protocolo do Teste de Integração Sensorial. RESULTADOS: Após a instituição da dieta, observou-se melhora objetiva significante nas condições que retratam a função vestibular e o equilíbrio corporal dos indivíduos estudados. CONCLUSÃO: Concluímos que o Teste de Integração Sensorial demonstrou ser uma ferramenta útil na documentação da melhora do equilíbrio corporal de pacientes portadores de DMA submetidos à dieta fracionada com restrição de glicose.
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Kawano H, Tono T, Kadomatsu K, Muramatsu T, Komune S. Expression of basigin, a member of the immunoglobulin superfamily, in the mouse cochlea. ORL J Otorhinolaryngol Relat Spec 2004; 65:327-31. [PMID: 14981325 DOI: 10.1159/000076050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2002] [Accepted: 09/30/2003] [Indexed: 11/19/2022]
Abstract
To elucidate the function of basigin (Bsg) in the mouse cochlea, its expression was investigated by reverse-transcription polymerase chain reaction (RT-PCR) and immunohistochemical staining. Amplification by RT-PCR of Bsg-specific primer pairs in total RNA extracted from the mouse cochlea revealed chain reaction products of the expected sizes. Sequence analysis confirmed that the product sequences were identical to sequences in known Bsg fragments. Although Bsg was negative in the capillaries within the cochlea, positive Bsg immunoreactivity was found in the capillaries of the auditory nerve and in the basal cells of the stria vascularis. These findings suggest that Bsg may play an important role in the maintenance of homeostasis, not only of the neural environment in the auditory nerve but also of cochlear fluid.
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Affiliation(s)
- Hirokazu Kawano
- Department of Otorhinolaryngology, Miyazaki Medical College, Kihara, Miyazaki, Japan.
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Kwun YS, Yeo SW, Ahn YH, Lim SW, Jung JY, Kim WY, Sands JM, Kim J. Immunohistochemical localization of urea transporters A and B in the rat cochlea. Hear Res 2003; 183:84-96. [PMID: 13679141 DOI: 10.1016/s0378-5955(03)00218-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Urea is present in the inner ear, and when it is administered, induces rapid changes in the volume and osmolality of the inner ear fluid. However, the regulating mechanisms are unknown. Two groups of urea transporters (UTs), the renal urea transporter (UT-A) and the erythrocyte urea transporter (UT-B) have been cloned recently. The aims of the current study were to investigate the cellular localization of UTs in the cochlea of male Sprague-Dawley rats by immunohistochemistry. Both UT-A1 and UT-B were expressed in the inner and outer pillar cells, inner and outer hair cells, Boettcher's cells, and Deiters' cells in the organ of Corti. Immunoreactivity for UT-A3 was localized only in the mesothelial cells underlying the basilar membrane. In the stria vascularis, UT-A1 was expressed only in the marginal cells, whereas UT-B was expressed only in the basal cells. In the spiral ganglion, most cells had strong UT-A1 immunoreactivity whereas UT-B was not expressed. In the spiral limbus, UT-B was expressed in the interdental cells whereas UT-A was not expressed. In the crista ampullaris, UT-A1 was expressed in the dark cells, and UT-B expressed in the apical membrane of supporting cells in the neuroepithelium. The distribution of UT-A and UT-B in the inner ear suggests that the cells that surround the inner ear fluids may be involved in urea transport and thus play an important role in fluid homeostasis in the inner ear. The expression of UT-A and UT-B in the hair cells raises the possibility that UTs may be involved in volume regulation in these cells and mediate hair cell turgor.
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Affiliation(s)
- Yong-Sig Kwun
- Department of Otolaryngology-Head and Neck Surgery, College of Medicine, The Catholic University of Korea, Seoul, South Korea
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Hurle B, Lane K, Kenney J, Tarantino LM, Bucan M, Brownstein BH, Ornitz DM. Physical mapping of the mouse tilted locus identifies an association between human deafness loci DFNA6/14 and vestibular system development. Genomics 2001; 77:189-99. [PMID: 11597144 DOI: 10.1006/geno.2001.6632] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The tilted (tlt) mouse carries a recessive mutation causing vestibular dysfunction. The defect in tlt homozygous mice is limited to the utricle and saccule of the inner ear, which completely lack otoconia. Genetic mapping of tlt placed it in a region orthologous with human 4p16.3-p15 that contains two loci, DFNA6 and DFNA14, responsible for autosomal dominant, nonsyndromic hereditary hearing impairment. To identify a possible relationship between tlt in mice and DFNA6 and DFNA14 in humans, we have refined the mouse genetic map, assembled a BAC contig spanning the tlt locus, and developed a comprehensive comparative map between mouse and human. We have determined the position of tlt relative to 17 mouse chromosome 5 genes with orthologous loci in the human 4p16.3-p15 region. This analysis identified an inversion between the mouse and human genomes that places tlt and DFNA6/14 in close proximity.
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Affiliation(s)
- B Hurle
- Department of Molecular Biology and Pharmacology, Washington University School of Medicine, 660 South Euclid Ave., St. Louis, Missouri 63110, USA
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