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Bächinger D, O’Malley JT, Wolf M, Bérnhard S, Liberman MC, Tibbitt MW, Eckhard AH. Poly(Ethylene Glycols) to Facilitate Celloidin Removal for Immunohistochemical Studies on Archival Human Brain and Temporal Bone Sections. J Histochem Cytochem 2024; 72:419-433. [PMID: 39054648 PMCID: PMC11308191 DOI: 10.1369/00221554241266287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2024] [Accepted: 06/13/2024] [Indexed: 07/27/2024] Open
Abstract
Pathology repositories worldwide store millions of celloidin-processed human brain and temporal bone (TB) sections vital for studying central nervous system diseases and sensory organs. However, accessing these sections for modern molecular-pathological research, like immunohistochemistry, is hindered by the challenge of removing celloidin without damaging tissue. In this study, we explored the use of polyethylene glycols (PEGs), a class of non-hazardous, ethylene glycol oligomers, combined with an improved section mounting technique, to gently and effectively dissolve celloidin from sections archived for up to 40 years. Optimizing our protocol involved exploring celloidin dissolution kinetics in PEGs of varying molecular weights and terminations, as well as different temperatures. Low molecular weight PEGs, particularly PEG 200, were the most efficient celloidin solvent. Nuclear magnetic resonance (NMR) spectroscopy of celloidin-PEG 200 dissolution products revealed no chemical alterations, suggesting pure solvation without chemical modification. Because the solvation of celloidin in PEG was inhibited by proteins, we further developed a protein-free mounting protocol allowing complete celloidin removal in 30 to 60 minutes by immersing in PEG 200. In summary, our approach overcomes major methodological hurdles, rendering decades-old archival celloidin sections viable for immunohistochemical and other molecular biological techniques, while enhancing safety and workflow efficiency.
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Affiliation(s)
- David Bächinger
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Zurich, Zurich, Switzerland; University of Zurich, Zurich, Switzerland
| | - Jennifer T. O’Malley
- Otopathology Laboratory, Department of Otolaryngology, Massachusetts Eye and Ear, Boston, Massachusetts
- Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts
| | - Morris Wolf
- Macromolecular Engineering Laboratory, Institute of Energy and Process Engineering, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Stephane Bérnhard
- Macromolecular Engineering Laboratory, Institute of Energy and Process Engineering, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - M. Charles Liberman
- Otopathology Laboratory, Department of Otolaryngology, Massachusetts Eye and Ear, Boston, Massachusetts
- Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts
| | - Mark W. Tibbitt
- Macromolecular Engineering Laboratory, Institute of Energy and Process Engineering, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Andreas H. Eckhard
- Otopathology Laboratory, Department of Otolaryngology, Massachusetts Eye and Ear, Boston, Massachusetts
- Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts
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Ghosh S, Lewis MB, Walters BJ. Comparison of ethylenediaminetetraacetic acid and rapid decalcificier solution for studying human temporal bones by immunofluorescence. Laryngoscope Investig Otolaryngol 2020; 5:919-927. [PMID: 33134540 PMCID: PMC7585256 DOI: 10.1002/lio2.449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 07/21/2020] [Accepted: 08/03/2020] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVES The pervasiveness of hearing loss and the development of new potential therapeutic approaches have led to increased animal studies of the inner ear. However, translational relevance of such studies depends upon verification of protein localization data in human samples. Cadavers used for anatomical education provide a potential research resource, but are limiting due to difficulties in accessing sensory tissues from the dense temporal bones. This study seeks to reduce the often months-long process of decalcification and improve immunofluorescent staining of human cadaveric temporal bones for research use. METHODS Temporal bones were decalcified in either (a) hydrochloric acid-containing RDO solution for 2 days followed by 0.5 M ethylenediaminetetraacetic acid (EDTA) for 3 to 5 additional days, or (b) 0.5 M EDTA alone for 2 to 4 weeks. Image-iT FX signal enhancer (ISE) was used to improve immunofluorescent signal-to-noise ratios. RESULTS The data indicate that both methods speed decalcification and allow for immunolabeling of the extranuclear proteins neurofilament (heavy chain), myosin VIIa, oncomodulin and prestin. However, RDO decalcification was more likely to alter structural morphology of sensory tissues and hindered effective labeling of the nuclear proteins SRY-box transcription factor 2 and GATA binding protein 3. CONCLUSIONS Although both approaches allow for rapid decalcification, EDTA appears superior to RDO for preserving cytoarchitecture and immunogenicity. LEVEL OF EVIDENCE NA.
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Affiliation(s)
- Sumana Ghosh
- Department of Neurobiology and Anatomical SciencesUniversity of Mississippi Medical CenterJacksonMississippiUSA
| | - Mark B. Lewis
- Department of Neurobiology and Anatomical SciencesUniversity of Mississippi Medical CenterJacksonMississippiUSA
| | - Bradley J. Walters
- Department of Neurobiology and Anatomical SciencesUniversity of Mississippi Medical CenterJacksonMississippiUSA
- Department Otolaryngology—Head and Neck SurgeryUniversity of Mississippi Medical CenterJacksonMississippiUSA
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Seo YJ, Brown D. Experimental Animal Models for Meniere's Disease: A Mini-Review. J Audiol Otol 2020; 24:53-60. [PMID: 32248670 PMCID: PMC7141995 DOI: 10.7874/jao.2020.00115] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 03/10/2020] [Indexed: 12/11/2022] Open
Abstract
Several novel animal models that represent the pathophysiological process of endolymphatic hydrops (ELH) of Meniere's disease (MD) have been developed. Animal models are important to identify and characterize the pathophysiology of ELH and to corroborate molecular and genetic findings in humans. This review of the current animal models will be useful in understanding the pathophysiology of and developing proper treatments for MD. Surgical animal models will be replaced by medication-induced animal models. Study models previously developed in guinea pigs will be developed in several smaller animals for ease of conducting molecular analysis. In this review, we provided updated resources including our previous studies regarding the current and desirable animal models for MD.
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Affiliation(s)
- Young Joon Seo
- Department of Otorhinolaryngology, Yonsei University Wonju College of Medicine, Wonju, Korea.,Research Institute of Hearing Enhancement, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Daniel Brown
- School of Pharmacy and Biomedical Sciences, Curtin University, Bentley, WA, Australia
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Abstract
In this review, we provide a description of the recent methods used for immunohistochemical staining of the human inner ear using formalin-fixed frozen, paraffin and celloidin-embedded sections. We also show the application of these immunohistochemical methods in auditory and vestibular endorgans microdissected from the human temporal bone. We compare the advantages and disadvantages of immunohistochemistry (IHC) in the different types of embedding media. IHC in frozen and paraffin-embedded sections yields a robust immunoreactive signal. Both frozen and paraffin sections would be the best alternative in the case where celloidin-embedding technique is not available. IHC in whole endorgans yields excellent results and can be used when desiring to detect regional variations of protein expression in the sensory epithelia. One advantage of microdissection is that the tissue is processed immediately and IHC can be made within 1 week of temporal bone collection. A second advantage of microdissection is the excellent preservation of both morphology and antigenicity. Using celloidin-embedded inner ear sections, we were able to detect several antigens by IHC and immunofluorescence using antigen retrieval methods. These techniques, previously applied only in animal models, allow for the study of numerous important proteins expressed in the human temporal bone potentially opening up a new field for future human inner ear research.
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Abstract
HYPOTHESIS Investigation of differential protein expression will provide clues to pathophysiology in otosclerosis. BACKGROUND Otosclerosis is a bone remodeling disorder limited to the endochondral layer of the otic capsule within the temporal bone. Some authors have suggested an inflammatory etiology for otosclerosis resulting from persistent measles virus infection involving the otic capsule. Despite numerous genetic studies, implication of candidate genes in the otosclerotic process remains elusive. We employed liquid chromatography-mass spectrometry (LC-MS) analysis on formalin-fixed celloidin-embedded temporal bone tissues for postmortem investigation of otosclerosis. METHODS Proteomic analysis was performed using human temporal bones from a patient with severe otosclerosis and a control temporal bone. Sections were dissected under microscopy to remove otosclerotic lesions and normal otic capsule for proteomic analysis. Tandem 2D chromatography mass spectrometry was employed. Data analysis and peptide matching to FASTA human databases was done using SEQUEST and proteome discoverer software. RESULTS TGFβ1 was identified in otosclerosis but not in the normal control temporal bone specimen. Aside from TGFβ1, many proteins and predicted cDNA-encoded proteins were observed, with implications in cell death and/or proliferation pathways, suggesting a possible role in otosclerotic bone remodeling. Immunostaining using TGFβ1 monoclonal revealed marked staining of the spongiotic otosclerotic lesions. CONCLUSIONS Mechanisms involved in cochlear extension of otosclerosis are still unclear, but the implication of TGFβ1 is supported by the present proteomic data and immunostaining results. The established role of TGFβ1 in the chondrogenesis process supports the theory of a reaction targeting the globulae interossei within the otic capsule.
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Takahashi M, Kimura Y, Sawabe M, Kitamura K. Modified paraffin-embedding method for the human cochlea that reveals a fine morphology and excellent immunostaining results. Acta Otolaryngol 2010; 130:788-92. [PMID: 20082565 DOI: 10.3109/00016480903426626] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CONCLUSION A modified paraffin-embedding method could be applied to histopathological and immunohistochemical studies of the human cochlea. The complementary use of molecular and immunohistochemical techniques by means of this method is thus considered to be a valuable tool for the future study of the human inner ear. OBJECTIVE To propose a new paraffin-embedding method for the morphological and immunohistochemical study of the human cochlea. METHODS Five human temporal bones were harvested at autopsy. The temporal bone specimens were fixed in 20% buffered formalin, decalcified with EDTA, cropped to a cube of approximately 15 mm, embedded in paraffin, and then cut into 6 microm thick sections. The sections were stained with hematoxylin and eosin, and immunostained with anti-prestin and anti-neurofilament antibodies. RESULTS Although paraffin-embedded sections cannot show the excellent morphology of the delicate membranous labyrinth obtained with celloidin, this technique successfully preserved the morphology of the cochlea, especially the organ of Corti, thereby enabling us to obtain excellent immunostaining results.
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O'Malley JT, Burgess BJ, Jones DD, Adams JC, Merchant SN. Techniques of celloidin removal from temporal bone sections. Ann Otol Rhinol Laryngol 2009; 118:435-441. [PMID: 19663375 PMCID: PMC2758402 DOI: 10.1177/000348940911800606] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
OBJECTIVES We sought to determine whether the technique of celloidin removal influences the results of immunostaining in celloidin-embedded cochleae. METHODS We compared four protocols of celloidin removal, including those using clove oil, acetone, ether-alcohol, and methanol saturated with sodium hydroxide. By optimally fixing our tissue (perfused mice), and keeping constant the fixative type (formalin plus acetic acid), fixation time (25 hours), and decalcification time (ethylenediaminetetraacetic acid for 7 days), we determined whether the technique of celloidin removal influenced the immunostaining results. Six antibodies were used with each removal method: prostaglandin D synthase, sodium, potassium adenosine triphosphatase (Na+,K(+)-ATPase), aquaporin 1, connective tissue growth factor, tubulin, and 200 kd neurofilament. RESULTS Clove oil, acetone, and ether-alcohol resulted in incomplete removal of the celloidin, thereby negatively affecting the results of immunostaining. The methanol-sodium hydroxide method was effective in completely removing the celloidin; it produced the cleanest and most reproducible immunostaining for all six antibodies. CONCLUSIONS Freshly prepared methanol saturated with sodium hydroxide and diluted 1:2 with methanol was the best solvent for removing celloidin from mouse temporal bone sections, resulting in consistent and reproducible immunostaining with the six antibodies tested.
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Affiliation(s)
- Jennifer T O'Malley
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, 243 Charles St, Boston, MA 02114, USA
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O'Malley JT, Merchant SN, Burgess BJ, Jones DD, Adams JC. Effects of fixative and embedding medium on morphology and immunostaining of the cochlea. Audiol Neurootol 2008; 14:78-87. [PMID: 18827478 DOI: 10.1159/000158536] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2008] [Accepted: 06/26/2008] [Indexed: 12/20/2022] Open
Abstract
The localization of proteins by immunostaining is a powerful method to investigate otologic disorders. However, the use of fixatives and embedding media (necessary for the preservation of morphology) can obscure antigens, making it difficult to perform immunoassays. We performed a systematic investigation of the effects of fixative and embedding medium on morphology and immunostaining of the mouse cochlea. Three different fixative solutions [4% formaldehyde (F), 4% formaldehyde + 1% acetic acid (FA), and 4% formaldehyde + 1% acetic acid + 0.1% glutaraldehyde (FGA)] and 3 different embedding media (paraffin, polyester wax, and celloidin) were used. Morphology was assessed using light microscopy. Immunostaining was studied using a panel of 6 antibodies (to prostaglandin D synthase, aquaporin 1, connective tissue growth factor, 200-kDa neurofilament, tubulin and Na(+),K(+)-ATPase). Preservation of morphology was suboptimal with paraffin, adequate with polyester wax and superb with celloidin. Immunostaining was successful using all 6 antibodies in all 3 fixatives and all 3 embedding media. While there were differences in strength of signal and localization of antigen between the 3 fixatives, overall, FA and FGA gave the most uniform results. For a given fixative and antibody, there was surprisingly little difference in the quality of immunostaining between celloidin and paraffin, while results in polyester wax were not as good in some cases. These results suggest that celloidin may be the embedding medium of choice for both morphological and pathological studies, including immunostaining when morphology must be optimized.
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Technical report: Immunofluorescence and TUNEL staining of celloidin embedded human temporal bone tissues. Hear Res 2008; 241:1-6. [DOI: 10.1016/j.heares.2008.04.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2008] [Revised: 04/22/2008] [Accepted: 04/24/2008] [Indexed: 11/23/2022]
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Merchant SN, Burgess B, O'Malley J, Jones D, Adams JC. Polyester wax: a new embedding medium for the histopathologic study of human temporal bones. Laryngoscope 2006; 116:245-9. [PMID: 16467713 PMCID: PMC2563155 DOI: 10.1097/01.mlg.0000192171.85406.47] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Celloidin and paraffin are the two common embedding mediums used for histopathologic study of the human temporal bone by light microscopy. Although celloidin embedding permits excellent morphologic assessment, celloidin is difficult to remove, and there are significant restrictions on success with immunostaining. Embedding in paraffin allows immunostaining to be performed, but preservation of cellular detail within the membranous labyrinth is relatively poor. OBJECTIVES/HYPOTHESIS Polyester wax is an embedding medium that has a low melting point (37 degrees C), is soluble in most organic solvents, is water tolerant, and sections easily. We hypothesized that embedding in polyester wax would permit good preservation of the morphology of the membranous labyrinth and, at the same time, allow the study of proteins by immunostaining. METHODS Nine temporal bones from individuals aged 1 to 94 years removed 2 to 31 hours postmortem, from subjects who had no history of otologic disease, were used. The bones were fixed using 10% formalin, decalcified using EDTA, embedded in polyester wax, and serially sectioned at a thickness of 8 to 12 mum on a rotary microtome. The block and knife were cooled with frozen CO2 (dry ice) held in a funnel above the block. Sections were placed on glass slides coated with a solution of 1% fish gelatin and 1% bovine albumin, followed by staining of selected sections with hematoxylin and eosin (H&E). Immunostaining was also performed on selected sections using antibodies to 200 kD neurofilament and Na-K-ATPase. RESULTS Polyester wax-embedded sections demonstrated good preservation of cellular detail of the organ of Corti and other structures of the membranous labyrinth, as well as the surrounding otic capsule. The protocol described in this paper was reliable and consistently yielded sections of good quality. Immunostaining was successful with both antibodies. CONCLUSION The use of polyester wax as an embedding medium for human temporal bones offers the advantage of good preservation of morphology and ease of immunostaining. We anticipate that in the future, polyester wax embedding will also permit other molecular biologic assays on temporal bone sections such as the retrieval of nucleic acids and the study of proteins using mass spectrometry-based proteomic analysis.
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Affiliation(s)
- Saumil N Merchant
- Otopathology Laboratory and the Department of Otolaryngology, MA Eye and Ear Infirmary, and the Department of Otology and Laryngology, Harvard Medical School, Boston, Massachusetts 02114, USA.
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Keithley EM, Harris B, Desai K, Linthicum F, Fischel-Ghodsian N. Mitochondrial cytochrome oxidase immunolabeling in aged human temporal bones. Hear Res 2001; 157:93-9. [PMID: 11470189 DOI: 10.1016/s0378-5955(01)00281-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Presbycusis, an age-related hearing loss, is accompanied by histopathological cochlear changes including variable amounts of degeneration of the auditory receptors, neurons and the stria vascularis. The causes of degeneration are unknown, although acoustic trauma and exposure to ototoxic agents are certainly contributors to the cellular degeneration. Acquired mitochondrial DNA defects are postulated as important determinants of aging in neuromuscular tissues. The cochlear neurons are highly metabolic and are, therefore, likely to be affected by mitochondrial DNA defects. Sequence analysis has demonstrated a significant number of acquired mutations in the cytochrome oxidase gene in the neurons from aged human cochleas. The current study used immunohistochemical labeling of cytochrome oxidase in the neuronal cell bodies in archival celloidin sections to evaluate relationships among label density, hearing loss, number of neurons and mitochondrial DNA changes within individual cochleas. Label density was less in many aged temporal bones, but not all. There was no relationship among any other variables. It is concluded that while there may be a decrease in the amount of cytochrome oxidase expression in aged spiral ganglion cell bodies, there are many other factors that contribute to hearing loss and cellular degeneration.
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Affiliation(s)
- E M Keithley
- Department of Surgery, University of California, San Diego, La Jolla, 92093, USA.
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Keithley EM, Truong T, Chandronait B, Billings PB. Immunohistochemistry and microwave decalcification of human temporal bones. Hear Res 2000; 148:192-6. [PMID: 10978836 DOI: 10.1016/s0378-5955(00)00153-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Processing of human temporal bones is a long, expensive process and the resulting celloidin sections are difficult to use for immunohistochemistry. We tested the ability of immunohistochemical assays to work in human temporal bones that were decalcified using a microwave oven. Tissue was trimmed to an approximate cube (1.5-2 cm/side) containing only the cochlea and immersed in fresh EDTA with paraformaldehyde every 6 h. This sized block required 190-400 h to decalcify. The decalcified tissue was embedded in paraffin and sectioned. Sections were immunoassayed with anti-cytochrome c oxidase, anti-neurofilament or anti-peripherin. All three antibodies labeled the appropriate structures. This procedure may stimulate advancement in the understanding of human inner ear pathology.
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Affiliation(s)
- E M Keithley
- Department of Surgery, Division of Otolaryngology, Head and Neck Surgery, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0666, USA.
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