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Gartling G, Nakamura R, Sayce L, Kimball EE, Wilson A, Schneeberger S, Zimmerman Z, Garabedian MJ, Branski RC, Rousseau B. Acute Effects of Systemic Glucocorticoids on the Vocal Folds in a Pre-Clinical Model. Ann Otol Rhinol Laryngol 2024; 133:87-96. [PMID: 37497827 PMCID: PMC10818023 DOI: 10.1177/00034894231188571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
OBJECTIVES/HYPOTHESIS Systemic glucocorticoids (GC)s are employed to treat various voice disorders. However, GCs have varying pharmacodynamic properties with adverse effects ranging from changes in epithelial integrity, skeletal muscle catabolism, and altered body weight. We sought to characterize the acute temporal effects of systemic dexamethasone and methylprednisolone on vocal fold (VF) epithelial glucocorticoid receptor (GR) nuclear translocation, epithelial tight junction (ZO-1) expression, thyroarytenoid (TA) muscle fiber morphology, and body weight using an established pre-clinical model. We hypothesized dexamethasone and methylprednisolone will elicit changes in VF epithelial GR nuclear translocation, epithelial ZO-1 expression, TA muscle morphology, and body weight compared to placebo-treated controls. METHODS Forty-five New Zealand white rabbits received intramuscular injections of methylprednisolone (4.5 mg; n = 15), dexamethasone (450 µg; n = 15), or volume matched saline (n = 15) into the iliocostalis/longissimus muscle for 6 consecutive days. Vocal folds from 5 rabbits from each treatment group were harvested at 1-, 3-, or 7 days following the final injection and subjected to immunohistochemistry for ZO-1 and GR as well as TA muscle fiber cross-sectional area (CSA) measures. RESULTS Dexamethasone increased epithelial GR nuclear translocation and ZO-1 expression 1-day following injections compared to methylprednisolone (P = .024; P = .012). Dexamethasone and methylprednisolone increased TA CSA 1-day following injections (P = .011). Methylprednisolone decreased body weight 7 days following injections compared to controls (P = .004). CONCLUSIONS Systemic dexamethasone may more efficiently activate GR in the VF epithelium with a lower risk of body weight loss, suggesting a role for more refined approaches to GC selection for laryngeal pathology.
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Affiliation(s)
- Gary Gartling
- Communication Science and Disorders, University of Pittsburgh, Pittsburgh, PA, USA
- Rehabilitation Medicine, NYU Grossman School of Medicine, New York, NY, USA
| | - Ryosuke Nakamura
- Rehabilitation Medicine, NYU Grossman School of Medicine, New York, NY, USA
| | - Lea Sayce
- Communication Science and Disorders, University of Pittsburgh, Pittsburgh, PA, USA
| | - Emily E. Kimball
- Hearing and Speech Sciences, Vanderbilt University, Nashville, TN, USA
- Otolaryngology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Azure Wilson
- Communication Science and Disorders, University of Pittsburgh, Pittsburgh, PA, USA
| | - Steven Schneeberger
- Plastic and Reconstructive Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Zachary Zimmerman
- Communication Science and Disorders, University of Pittsburgh, Pittsburgh, PA, USA
| | - Michael J. Garabedian
- Microbiology, NYU Grossman School of Medicine, New York, NY, USA
- Department of Urology, NYU Grossman School of Medicine, New York, NY, USA
| | - Ryan C. Branski
- Rehabilitation Medicine, NYU Grossman School of Medicine, New York, NY, USA
- Otolaryngology-Head and Neck Surgery, NYU Grossman School of Medicine, New York, NY, USA
| | - Bernard Rousseau
- Doisy College of Health Sciences, Saint Louis University, St. Louis, MO, USA
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Gartling G, Nakamura R, Bing R, Branski RC. A Novel Method for Thyroarytenoid Myofiber Culture. Laryngoscope 2023; 133:3109-3115. [PMID: 37227163 DOI: 10.1002/lary.30756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/20/2023] [Accepted: 04/29/2023] [Indexed: 05/26/2023]
Abstract
OBJECTIVES/HYPOTHESIS Myofiber culture has been employed to investigate muscle physiology in vitro and is well-established in the rodent hind limb. Thyroarytenoid (TA) myofiber culture has not been described, providing an opportunity to employ this method to investigate distinct TA myofiber functions. The purpose of this study was to assess the feasibility of a TA myofiber culture model. STUDY DESIGN In vitro. METHODS TA muscles from five Sprague Dawley rats were independently isolated and digested for 90 min. A smooth-tip, wide-bored pipette dissociated TA myofibers from cartilage, and the fibers were distributed on collagen-coated dishes and incubated at 37°C, 5% CO2 for 2 h. Myofiber specificity was determined via immunolabeling for desmin and myosin heavy chain (MHC). Myofibers viability was assessed over 7 days via esterase assay. Additional myofibers were immunolabeled for satellite cell marker Pax-7. Glucocorticoid (GC) receptor (GR) was immunolabeled following GC treatment. RESULTS The harvest technique yielded ~120 myofibers per larynx. By day 7, ~60% of the fibers remained attached and were calcein AM-positive/ethidium homodimer-negative, indicating viability. Myofibers were positive for desmin and MHC, indicating muscle specificity. Cells surrounding myofibers were positive for Pax-7, indicating the presence of myogenic satellite cells. Myofibers also responded to GC treatment as determined by GR nuclear translocation. CONCLUSION TA myofibers remained viable in culture for at least 7 days with a predictable response to exogenous stimuli. This technique provides novel investigative opportunities regarding TA structure and function. LEVEL OF EVIDENCE N/A Laryngoscope, 133:3109-3115, 2023.
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Affiliation(s)
- Gary Gartling
- Rehabilitation Medicine, NYU Grossman School of Medicine, New York City, New York, USA
| | - Ryosuke Nakamura
- Rehabilitation Medicine, NYU Grossman School of Medicine, New York City, New York, USA
| | - Renjie Bing
- Rehabilitation Medicine, NYU Grossman School of Medicine, New York City, New York, USA
| | - Ryan C Branski
- Rehabilitation Medicine, NYU Grossman School of Medicine, New York City, New York, USA
- Otolaryngology-Head and Neck Surgery, NYU Grossman School of Medicine, New York City, New York, USA
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Gartling G, Nakamura R, Sayce L, Zimmerman Z, Slater A, Wilson A, Bing R, Branski RC, Rousseau B. Acute In Vitro and In Vivo Effects of Dexamethasone in the Vocal Folds: a Pilot Study. Laryngoscope 2023; 133:2264-2270. [PMID: 36317801 PMCID: PMC10149570 DOI: 10.1002/lary.30461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 09/29/2022] [Accepted: 10/06/2022] [Indexed: 11/06/2022]
Abstract
OBJECTIVES/HYPOTHESIS Glucocorticoids (GC)s are commonly employed to treat vocal fold (VF) pathologies. However, VF atrophy has been associated with intracordal GC injections. Dexamethasone-induced skeletal muscle atrophy is well-documented in other tissues and believed to be mediated by increased muscle proteolysis via upregulation of Muscle Ring Finger (MuRF)-1 and Atrogin-1. Mechanisms of dexamethasone-mediated VF atrophy have not been described. This pilot study employed in vitro and in vivo models to investigate the effects of dexamethasone on VF epithelium, thyroarytenoid (TA) muscle, and TA-derived myoblasts. We hypothesized that dexamethasone will increase atrophy-associated gene expression in TA muscle and myoblasts and decrease TA muscle fiber size and epithelial thickness. STUDY DESIGN In vitro, pre-clinical. METHODS TA myoblasts were isolated from a female Sprague-Dawley rat and treated with 1 μM dexamethasone for 24-h. In vivo, 15 New Zealand white rabbits were randomly assigned to three treatment groups: (1) bilateral intracordal injection of 40 μL dexamethasone (10 mg/ml; n = 5), (2) volume-matched saline (n = 5), and (3) untreated controls (n = 5). Larynges were harvested 7-days post-injection. Across in vivo and in vitro experimentation, MuRF-1 and Atrogin-1 mRNA expression were measured via RT-qPCR. TA muscle fiber cross-sectional area (CSA) and epithelial thickness were also quantified in vivo. RESULTS Dexamethasone increased MuRF-1 gene expression in TA myoblasts. Dexamethasone injection, however, did not alter atrophy-associated gene expression, TA CSA, or epithelial thickness in vivo. CONCLUSION Dexamethasone increased atrogene expression in TA myoblasts, providing foundational insight into GC induced atrophic gene transcription. Repeated dexamethasone injections may be required to elicit atrophy in vivo. LEVEL OF EVIDENCE NA Laryngoscope, 133:2264-2270, 2023.
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Affiliation(s)
- Gary Gartling
- Department of Rehabilitation Medicine, NYU Grossman School of Medicine, New York, NY
- Department of Communication Science and Disorders, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA
| | - Ryosuke Nakamura
- Department of Rehabilitation Medicine, NYU Grossman School of Medicine, New York, NY
| | - Lea Sayce
- Department of Communication Science and Disorders, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA
| | - Zachary Zimmerman
- Department of Communication Science and Disorders, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA
| | - Alysha Slater
- Department of Communication Science and Disorders, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA
| | - Azure Wilson
- Department of Communication Science and Disorders, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA
| | - Renjie Bing
- Department of Rehabilitation Medicine, NYU Grossman School of Medicine, New York, NY
| | - Ryan C. Branski
- Department of Rehabilitation Medicine, NYU Grossman School of Medicine, New York, NY
- Department of Otolaryngology-Head and Neck Surgery, NYU Grossman School of Medicine, New York, NY
| | - Bernard Rousseau
- Department of Communication Science and Disorders, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA
- Doisy College of Health Sciences, Saint Louis University, St. Louis, MO
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Wilson A, Sayce L, Li Z, Gartling G, Luo H, Rousseau B. Custom Laser-Cut Silastic® Implants for Type I Thyroplasty in a Preclinical Model. ORL J Otorhinolaryngol Relat Spec 2023; 85:294-298. [PMID: 37232013 PMCID: PMC10990462 DOI: 10.1159/000530419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 03/23/2023] [Indexed: 05/27/2023]
Abstract
This study aimed to produce customized silicone elastomer implants of varied size and shape for optimization of type I thyroplasty procedures in a rabbit model. Computer-aided design models of different implant designs were designed and used to program laser cutting of a medical-grade Silastic® sheet. Laser-cut implants were produced rapidly and cost-efficiently. Surgical implantation demonstrated vocal fold medialization and phonation in 5 test subjects. This technique may provide a low-cost alternative or adjunct method to hand-carving or commercial implants.
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Affiliation(s)
- Azure Wilson
- Department of Communication Science and Disorders, University of Pittsburgh, Pittsburgh, (Pennsylvania,) United States
| | - Lea Sayce
- Department of Communication Science and Disorders, University of Pittsburgh, Pittsburgh, (Pennsylvania,) United States
| | - Zheng Li
- Department of Mechanical Engineering, Vanderbilt University, Nashville, (TN,) United States
| | - Gary Gartling
- Department of Communication Science and Disorders, University of Pittsburgh, Pittsburgh, (Pennsylvania,) United States
| | - Haoxiang Luo
- Department of Mechanical Engineering, Vanderbilt University, Nashville, (TN,) United States
| | - Bernard Rousseau
- Department of Communication Science and Disorders, University of Pittsburgh, Pittsburgh, (Pennsylvania,) United States
- Doisy College of Health Sciences, St. Louis University, St. Louis, (MO,) United States
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Sayce L, Zimmerman Z, Gartling G, Rousseau B, Branski RC. Epithelial response to vocal fold microflap injury in a preclinical model. Laryngoscope 2023; 133:350-356. [PMID: 35538915 PMCID: PMC11066888 DOI: 10.1002/lary.30169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 04/01/2022] [Accepted: 04/05/2022] [Indexed: 01/19/2023]
Abstract
OBJECTIVES Functional outcomes following microflap surgery for vocal fold pathology are favorable. Although the stratified squamous epithelium appears to heal rapidly, persistent physiologic tissue alterations are likely. We sought to elucidate key biochemical processes including recruitment of immune cells, regulation of cellular junction proteins, and long-term alterations to epithelial tissue permeability following microflap with an eye toward enhanced clinical outcomes. METHODS Forty New Zealand rabbits were assigned to eight groups (n = 5/group): no-injury control or bilateral microflap with survival for 0 h, 12 h, 1 day, 3 days, 7 days, 30 days, and 60 days post-microflap. The epithelium was dissected from one vocal fold and transepithelial resistance was quantified. The contralateral fold was subjected to transmission electron microscopy. Images were evaluated by a blinded rater and paracellular space dilation was quantified using ImageJ. Immune cell infiltration was evaluated and recorded qualitatively. RESULTS Increased innate immune response was observed 12 h as well as 7 and 30 days after microflap. At 60 days following injury, decreased epithelial resistance was observed. Paracellular spaces were dilated at all time-points following injury. CONCLUSIONS The vocal fold epithelium was significantly altered at 60 days following microflap. The implications for this tissue phenotype are unclear. However, compromised epithelial barrier function is implicated in various diseases and may increase the risk of subsequent injury. LEVEL OF EVIDENCE NA Laryngoscope, 133:350-356, 2023.
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Affiliation(s)
- Lea Sayce
- Communication Science and Disorders, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A
| | - Zachary Zimmerman
- Communication Science and Disorders, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A
| | - Gary Gartling
- Communication Science and Disorders, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A
- Rehabilitation Medicine, NYU Grossman School of Medicine, New York, U.S.A
| | - Bernard Rousseau
- Communication Science and Disorders, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A
| | - Ryan C Branski
- Rehabilitation Medicine, NYU Grossman School of Medicine, New York, U.S.A
- Otolaryngology-Head and Neck Surgery, NYU Grossman School of Medicine, New York, U.S.A
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