1
|
Zalewski CK, Sydlowski SA, King KA, Bianconi S, Dang Do A, Porter FD, Brewer CC. Auditory phenotype of Smith-Lemli-Opitz syndrome. Am J Med Genet A 2021; 185:1131-1141. [PMID: 33529473 DOI: 10.1002/ajmg.a.62087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 12/23/2020] [Accepted: 01/07/2021] [Indexed: 11/11/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive multiple congenital malformation and intellectual disability syndrome resulting from variants in DHCR7. Auditory characteristics of persons with SLOS have been described in limited case reports but have not been systematically evaluated. The objective of this study is to describe the auditory phenotype in SLOS. Age- and ability-appropriate hearing evaluations were conducted on 32 patients with SLOS. A subset of 21 had auditory brainstem response testing, from which an auditory neural phenotype is described. Peripheral or retrocochlear auditory dysfunction was observed in at least one ear of 65.6% (21) of the patients in our SLOS cohort. The audiometric phenotype was heterogeneous and included conductive, mixed, and sensorineural hearing loss. The most common presentation was a slight to mild conductive hearing loss, although profound sensorineural hearing loss was also observed. Abnormal auditory brainstem responses indicative of retrocochlear dysfunction were identified in 21.9% of the patients. Many were difficult to test behaviorally and required objective assessment methods to estimate hearing sensitivity. Individuals with SLOS are likely to have hearing loss that may impact communication, including speech and language development. Routine audiologic surveillance should be conducted to ensure prompt management of hearing loss.
Collapse
Affiliation(s)
| | - Sarah A Sydlowski
- NIDCD, National Institutes of Health, Bethesda, Maryland, USA.,Cleveland Clinic Head & Neck Institute, Cleveland, Ohio, USA
| | - Kelly A King
- NIDCD, National Institutes of Health, Bethesda, Maryland, USA
| | - Simona Bianconi
- NICHD, National Institutes of Health, Bethesda, Maryland, USA
| | - An Dang Do
- NICHD, National Institutes of Health, Bethesda, Maryland, USA
| | - Forbes D Porter
- NICHD, National Institutes of Health, Bethesda, Maryland, USA
| | - Carmen C Brewer
- NIDCD, National Institutes of Health, Bethesda, Maryland, USA
| |
Collapse
|
2
|
Wang H, Lin C, Yao J, Shi H, Zhang C, Wei Q, Lu Y, Chen Z, Xing G, Cao X. Deletion of OSBPL2 in auditory cells increases cholesterol biosynthesis and drives reactive oxygen species production by inhibiting AMPK activity. Cell Death Dis 2019; 10:627. [PMID: 31427568 PMCID: PMC6700064 DOI: 10.1038/s41419-019-1858-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Revised: 07/25/2019] [Accepted: 07/30/2019] [Indexed: 02/07/2023]
Abstract
Oxysterol-binding protein like 2 (OSBPL2) was identified as a novel causal gene for autosomal dominant nonsyndromic hearing loss. However, the pathogenesis of OSBPL2 deficits in ADNSHL was still unclear. The function of OSBPL2 as a lipid-sensing regulator in multiple cellular processes suggested that OSBPL2 might play an important role in the regulation of cholesterol-homeostasis, which was essential for inner ear. In this study the potential roles of OSBPL2 in cholesterol biosynthesis and ROS production were investigated in Osbpl2-KO OC1 cells and osbpl2b-KO zebrafish. RNA-seq-based analysis suggested that OSBPL2 was implicated in cholesterol biosynthesis and AMPK signaling pathway. Furthermore, Osbpl2/osbpl2b-KO resulted in a reduction of AMPK activity and up-regulation of Srebp2/srebp2, Hmgcr/hmgcr and Hmgcs1/hmgcs1, key genes in the sterol biosynthetic pathway and associated with AMPK signaling. In addition, OSBPL2 was also found to interact with ATIC, key activator of AMPK. The levels of total cholesterol and ROS in OC1 cells or zebrafish inner ear were both increased in Osbpl2/osbpl2b-KO mutants and the mitochondrial damage was detected in Osbpl2-KO OC1 cells. This study uncovered the regulatory roles of OSBPL2 in cellular cholesterol biosynthesis and ROS production. These founds might contribute to the deep understanding of the pathogenesis of OSBPL2 mutation in ADNSHL.
Collapse
Affiliation(s)
- Hongshun Wang
- Department of Medical Genetics, School of Basic Medical Science, Nanjing Medical University, Nanjing, China
| | - Changsong Lin
- Department of Medical Genetics, School of Basic Medical Science, Nanjing Medical University, Nanjing, China
| | - Jun Yao
- Department of Medical Genetics, School of Basic Medical Science, Nanjing Medical University, Nanjing, China.,Jiangsu Key Laboratory of Xenotransplantation, Nanjing Medical University, Nanjing, China
| | - Hairong Shi
- Department of Medical Genetics, School of Basic Medical Science, Nanjing Medical University, Nanjing, China
| | - Cui Zhang
- Department of Medical Genetics, School of Basic Medical Science, Nanjing Medical University, Nanjing, China
| | - Qinjun Wei
- Department of Medical Genetics, School of Basic Medical Science, Nanjing Medical University, Nanjing, China.,Jiangsu Key Laboratory of Xenotransplantation, Nanjing Medical University, Nanjing, China.,The Laboratory Center for Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Yajie Lu
- Department of Medical Genetics, School of Basic Medical Science, Nanjing Medical University, Nanjing, China.,Jiangsu Key Laboratory of Xenotransplantation, Nanjing Medical University, Nanjing, China
| | - Zhibin Chen
- Department of Otolaryngology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Guangqian Xing
- Department of Otolaryngology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Xin Cao
- Department of Medical Genetics, School of Basic Medical Science, Nanjing Medical University, Nanjing, China. .,Jiangsu Key Laboratory of Xenotransplantation, Nanjing Medical University, Nanjing, China. .,The Laboratory Center for Basic Medical Sciences, Nanjing Medical University, Nanjing, China.
| |
Collapse
|
3
|
OSBPL2-disrupted pigs recapitulate dual features of human hearing loss and hypercholesterolaemia. J Genet Genomics 2019; 46:379-387. [PMID: 31451425 DOI: 10.1016/j.jgg.2019.06.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 06/03/2019] [Accepted: 06/04/2019] [Indexed: 02/06/2023]
Abstract
Oxysterol binding protein like 2 (OSBPL2), an important regulator in cellular lipid metabolism and transport, was identified as a novel deafness-causal gene in our previous work. To resemble the phenotypic features of OSBPL2 mutation in animal models and elucidate the potential genotype-phenotype associations, the OSBPL2-disrupted Bama miniature (BM) pig model was constructed using CRISPR/Cas9-mediated gene editing, somatic cell nuclear transfer (SCNT) and embryo transplantation approaches, and then subjected to phenotypic characterization of auditory function and serum lipid profiles. The OSBPL2-disrupted pigs displayed progressive hearing loss (HL) with degeneration/apoptosis of cochlea hair cells (HCs) and morphological abnormalities in HC stereocilia, as well as hypercholesterolaemia. High-fat diet (HFD) feeding aggravated the development of HL and led to more severe hypercholesterolaemia. The dual phenotypes of progressive HL and hypercholesterolaemia resembled in OSBPL2-disrupted pigs confirmed the implication of OSBPL2 mutation in nonsydromic hearing loss (NSHL) and contributed to the potential linkage between auditory dysfunction and dyslipidaemia/hypercholesterolaemia.
Collapse
|
4
|
Deepika P, Rajeshwary A, Usha S, Goutham MK, Raghav S. Does dyslipidemia worsen the hearing level in diabetics? J Otol 2018; 12:198-201. [PMID: 29937856 PMCID: PMC6002627 DOI: 10.1016/j.joto.2017.07.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 07/18/2017] [Accepted: 07/20/2017] [Indexed: 02/02/2023] Open
Abstract
Objective To identify the effect of dyslipidemia on auditory function detected by Pure Tone Audiometry. To check if dyslipidemia worsens the hearing level in diabetics. Design This was a comparative study where 120 subjects between the age group of 20 and 50 years underwent pure tone audiometry, lipid profile and blood sugars. Group 1 consisted of 30 subjects with type 2 diabetes and dyslipidemia; Group 2 had 30 subjects with isolated diabetes; Group 3 had 30 with isolated dyslipidemia and Group 4 included 30 normal subjects as control. Results Significant hearing loss was seen only in the group with isolated diabetes (63%). The most common type of hearing loss was high frequency sensorineural hearing loss. When comparison was made between the combinations of different lipid profiles, no association was found to the level of hearing. Conclusions Diabetics are more prone to high frequency hearing loss. Altered lipid profile has no role in causing hearing loss.
Collapse
Affiliation(s)
- Pratap Deepika
- Dept of Otorhinolaryngology, KSHEMA, Nitte University, Mangalore 575018, India
| | - A Rajeshwary
- Dept of Otorhinolaryngology, KSHEMA, Nitte University, Mangalore 575018, India
| | - Shastri Usha
- Dept of Audiology and Speech Language Pathology, Nitte Institute of Speech and Hearing, Mangalore 575018, India
| | - M K Goutham
- Dept of Otorhinolaryngology, KSHEMA, Nitte University, Mangalore 575018, India
| | - Sharma Raghav
- Dept of Medicine, KSHEMA, Nitte University, Mangalore 575018, India
| |
Collapse
|
5
|
Malgrange B, Varela-Nieto I, de Medina P, Paillasse MR. Targeting cholesterol homeostasis to fight hearing loss: a new perspective. Front Aging Neurosci 2015; 7:3. [PMID: 25688206 PMCID: PMC4310297 DOI: 10.3389/fnagi.2015.00003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 01/08/2015] [Indexed: 01/01/2023] Open
Abstract
Sensorineural hearing loss (SNHL) is a major pathology of the inner ear that affects nearly 600 million people worldwide. Despite intensive researches, this major health problem remains without satisfactory solutions. The pathophysiological mechanisms involved in SNHL include oxidative stress, excitotoxicity, inflammation, and ischemia, resulting in synaptic loss, axonal degeneration, and apoptosis of spiral ganglion neurons. The mechanisms associated with SNHL are shared with other neurodegenerative disorders. Cholesterol homeostasis is central to numerous pathologies including neurodegenerative diseases and cholesterol regulates major processes involved in neurons survival and function. The role of cholesterol homeostasis in the physiopathology of inner ear is largely unexplored. In this review, we discuss the findings concerning cholesterol homeostasis in neurodegenerative diseases and whether it should be translated into potential therapeutic strategies for the treatment of SNHL.
Collapse
Affiliation(s)
- Brigitte Malgrange
- GIGA-Neurosciences, Developmental Neurobiology Unit, University of Liege , Liege , Belgium
| | - Isabel Varela-Nieto
- Instituto de Investigaciones Biomédicas "Alberto Sols", CSIC-UAM. IdiPAZ, CIBERER Instituto de Salud Carlos III. Arturo Duperier 4 , Madrid , Spain
| | | | | |
Collapse
|
6
|
Thomas PV, Cheng AL, Colby CC, Liu L, Patel CK, Josephs L, Duncan RK. Localization and proteomic characterization of cholesterol-rich membrane microdomains in the inner ear. J Proteomics 2014; 103:178-93. [PMID: 24713161 DOI: 10.1016/j.jprot.2014.03.037] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 03/25/2014] [Accepted: 03/26/2014] [Indexed: 12/14/2022]
Abstract
UNLABELLED Biological membranes organize and compartmentalize cell signaling into discrete microdomains, a process that often involves stable, cholesterol-rich platforms that facilitate protein-protein interactions. Polarized cells with distinct apical and basolateral cell processes rely on such compartmentalization to maintain proper function. In the cochlea, a variety of highly polarized sensory and non-sensory cells are responsible for the early stages of sound processing in the ear, yet little is known about the mechanisms that traffic and organize signaling complexes within these cells. We sought to determine the prevalence, localization, and protein composition of cholesterol-rich lipid microdomains in the cochlea. Lipid raft components, including the scaffolding protein caveolin and the ganglioside GM1, were found in sensory, neural, and glial cells. Mass spectrometry of detergent-resistant membrane (DRM) fractions revealed over 600 putative raft proteins associated with subcellular localization, trafficking, and metabolism. Among the DRM constituents were several proteins involved in human forms of deafness including those involved in ion homeostasis, such as the potassium channel KCNQ1, the co-transporter SLC12A2, and gap junction proteins GJA1 and GJB6. The presence of caveolin in the cochlea and the abundance of proteins in cholesterol-rich DRM suggest that lipid microdomains play a significant role in cochlear physiology. BIOLOGICAL SIGNIFICANCE Although mechanisms underlying cholesterol synthesis, homeostasis, and compartmentalization in the ear are poorly understood, there are several lines of evidence indicating that cholesterol is a key modulator of cochlear function. Depletion of cholesterol in mature sensory cells alters calcium signaling, changes excitability during development, and affects the biomechanical processes in outer hair cells that are responsible for hearing acuity. More recently, we have established that the cholesterol-modulator beta-cyclodextrin is capable of inducing significant and permanent hearing loss when delivered subcutaneously at high doses. We hypothesize that proteins involved in cochlear homeostasis and otopathology are partitioned into cholesterol-rich domains. The results of a large-scale proteomic analysis point to metabolic processes, scaffolding/trafficking, and ion homeostasis as particularly associated with cholesterol microdomains. These data offer insight into the proteins and protein families that may underlie cholesterol-mediated effects in sensory cell excitability and cyclodextrin ototoxicity.
Collapse
Affiliation(s)
- Paul V Thomas
- Kresge Hearing Research Institute, 5323 Medical Science Building I, 1150 West Medical Center Drive, The University of Michigan, Ann Arbor, MI 48109-5616, USA
| | - Andrew L Cheng
- Kresge Hearing Research Institute, 5323 Medical Science Building I, 1150 West Medical Center Drive, The University of Michigan, Ann Arbor, MI 48109-5616, USA
| | - Candice C Colby
- Kresge Hearing Research Institute, 5323 Medical Science Building I, 1150 West Medical Center Drive, The University of Michigan, Ann Arbor, MI 48109-5616, USA
| | - Liqian Liu
- Kresge Hearing Research Institute, 5323 Medical Science Building I, 1150 West Medical Center Drive, The University of Michigan, Ann Arbor, MI 48109-5616, USA
| | - Chintan K Patel
- Kresge Hearing Research Institute, 5323 Medical Science Building I, 1150 West Medical Center Drive, The University of Michigan, Ann Arbor, MI 48109-5616, USA
| | - Lydia Josephs
- Kresge Hearing Research Institute, 5323 Medical Science Building I, 1150 West Medical Center Drive, The University of Michigan, Ann Arbor, MI 48109-5616, USA
| | - R Keith Duncan
- Kresge Hearing Research Institute, 5323 Medical Science Building I, 1150 West Medical Center Drive, The University of Michigan, Ann Arbor, MI 48109-5616, USA.
| |
Collapse
|
7
|
Crumling MA, Liu L, Thomas PV, Benson J, Kanicki A, Kabara L, Hälsey K, Dolan D, Duncan RK. Hearing loss and hair cell death in mice given the cholesterol-chelating agent hydroxypropyl-β-cyclodextrin. PLoS One 2012; 7:e53280. [PMID: 23285273 PMCID: PMC3532434 DOI: 10.1371/journal.pone.0053280] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 11/28/2012] [Indexed: 11/18/2022] Open
Abstract
Cyclodextrins are sugar compounds that are increasingly finding medicinal uses due to their ability to complex with hydrophobic molecules. One cyclodextrin in particular, 2-hydroxypropyl-β-cyclodextrin (HPβCD), is used as a carrier to solubilize lipophilic drugs and is itself being considered as a therapeutic agent for treatment of Niemann-Pick Type C disease, due to its ability to mobilize cholesterol. Results from toxicological studies suggest that HPβCD is generally safe, but a recent study has found that it causes hearing loss in cats. Whether the hearing loss occurred via death of cochlear hair cells, rendering it permanent, was unexplored. In the present study, we examined peripheral auditory function and cochlear histology in mice after subcutaneous injection of HPβCD to test for hearing loss and correlate any observed auditory deficits with histological findings. On average, auditory brainstem response thresholds were elevated at 4, 16, and 32 kHz in mice one week after treatment with 8,000 mg/kg. In severely affected mice all outer hair cells were missing in the basal half of the cochlea. In many cases, surviving hair cells in the cochlear apex exhibited abnormal punctate distribution of the motor protein prestin, suggesting long term changes to membrane composition and integrity. Mice given a lower dose of 4,000 mg/kg exhibited hearing loss only after repeated doses, but these threshold shifts were temporary. Therefore, cyclodextrin-induced hearing loss was complex, involving cell death and other more subtle influences on cochlear physiology.
Collapse
Affiliation(s)
- Mark A. Crumling
- Kresge Hearing Research Institute, Department of Otolaryngology - Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Liqian Liu
- Kresge Hearing Research Institute, Department of Otolaryngology - Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Paul V. Thomas
- Kresge Hearing Research Institute, Department of Otolaryngology - Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Jennifer Benson
- Kresge Hearing Research Institute, Department of Otolaryngology - Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Ariane Kanicki
- Kresge Hearing Research Institute, Department of Otolaryngology - Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Lisa Kabara
- Kresge Hearing Research Institute, Department of Otolaryngology - Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Karin Hälsey
- Kresge Hearing Research Institute, Department of Otolaryngology - Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan, United States of America
| | - David Dolan
- Kresge Hearing Research Institute, Department of Otolaryngology - Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan, United States of America
| | - R. Keith Duncan
- Kresge Hearing Research Institute, Department of Otolaryngology - Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail:
| |
Collapse
|