1
|
Schiel V, Xia A, Santa Maria PL. Influence of CX3CR1 Deletion on Cochlear Hair Cell Survival and Macrophage Expression in Chronic Suppurative Otitis Media. Otol Neurotol 2023; 44:605-610. [PMID: 37315234 PMCID: PMC10275455 DOI: 10.1097/mao.0000000000003884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
OBJECTIVE Our objective was to determine whether the receptor CX3CR1 is necessary for the recruitment of macrophages to the cochlea in chronic suppurative otitis media (CSOM) and if its deletion can prevent hair cell loss in CSOM. BACKGROUND CSOM is a neglected disease that afflicts 330 million people worldwide and is the most common cause of permanent hearing loss among children in the developing world. It is characterized by a chronically discharging infected middle ear. We have previously demonstrated that CSOM causes macrophage associated sensory hearing loss. The receptor CX3CR1 is expressed on macrophages, which have been shown to be increased at the time point of outer hair cell (OHC) loss in CSOM. METHODS In this report, we examine the influence of CX3CR1 deletion (CX3CR1-/-) in a validated model of Pseudomonas aeruginosa (PA) CSOM. RESULTS The data show no difference in OHC loss between the CX3CR1-/- CSOM group and CX3CR1+/+ CSOM group (p = 0.28). We observed partial OHC loss in the cochlear basal turn, no OHC loss in the middle and apical turns in both CX3CR1-/- and CX3CR1+/+ CSOM mice at 14 days after bacterial inoculation. No inner hair cell (IHC) loss was found in all cochlear turns in all groups. We also counted F4/80 labeled macrophages in the spiral ganglion, spiral ligament, stria vascularis and spiral limbus of the basal, middle, and apical turn in cryosections. We did not find a significant difference in the total number of cochlear macrophages between CX3CR1-/- mice and CX3CR1+/+ mice (p = 0.97). CONCLUSION The data did not support a role for CX3CR1 macrophage associated HC loss in CSOM.
Collapse
Affiliation(s)
- Viktoria Schiel
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Palo Alto, California
| | | | | |
Collapse
|
2
|
Kaufman AC, Bacacao BS, Berkay B, Sharma D, Mishra A, O’Toole GA, Saunders JE, Xia A, Bekale LA, Maria PLS. Povidone-Iodine Fails to Eradicate Chronic Suppurative Otitis Media and Demonstrates Ototoxic Risk in Mice. Otol Neurotol 2022; 43:e1121-e1128. [PMID: 36240734 PMCID: PMC10244885 DOI: 10.1097/mao.0000000000003726] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [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: 01/07/2023]
Abstract
HYPOTHESIS Commercially available povidone-iodine solution can eliminate biofilms and persister cells rapidly in in vivo achievable concentrations without inducing ototoxicity. BACKGROUND Chronic suppurative otitis media (CSOM) is a substantial global problem. Current treatment options often induce a temporary remission without leading to a permanent cessation of symptoms secondary to the treatments' inability to eliminate persister cells. Povidone-iodine has been shown to be able to clear biofilm and planktonic cells in in vitro assays, but there are reports of ototoxic effects limiting its clinical utility. METHODS Bacterial and biofilm growth with quantification by spectrophotomer, murine auditory brainstem response (ABR), and distortion product otoacoustic emissions, immunohistochemistry, in vivo povidone-iodine treatment of murine CSOM, persister cell assay. RESULTS Commercially available 10% povidone-iodine solution is able to completely eradicate multiple clinical strains of Pseudomonas aeruginosa and Staphylococcus aureus in vitro with 10 minutes of exposure. Mice that have received a transtympanic injection of 1% povidone-iodine solution did not have significantly different auditory brainstem response or distortion product otoacoustic emission results compared with the control. Mice that received a povidone-iodine scrub or 10% povidone-iodine solution had significantly worsened hearing (25- and 13-dB increase in threshold, respectively; p < 0.05). In vivo CSOM infection recurred in all mice after the completion of treatment with 10% povidone-iodine solution, and there was no improvement in the bacterial load after treatment, indicating in vivo failure of therapy. CONCLUSION Povidone-iodine solution is effective at eliminating biofilm and persister cells in vitro at in vivo achievable concentrations but fails in vivo most likely because of kinetics of distribution in vivo. Even if drug distribution could be improved, the therapeutic window is likely to be too small given that the diluted solution does not have ototoxic potential, whereas while the scrub variant, which contains detergents, and the undiluted solution are ototoxic after a single treatment.
Collapse
Affiliation(s)
- Adam C. Kaufman
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Palo Alto, California
| | - Brian S. Bacacao
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Palo Alto, California
| | - Betul Berkay
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Palo Alto, California
| | - Devesh Sharma
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Palo Alto, California
| | - Anupam Mishra
- Department of Otorhinolaryngology, Head and Neck Surgery, King George’s Medical University, Lucknow, India
| | - George A. O’Toole
- Department of Microbiology and Immunology, Dartmouth University, Hanover, New Hampshire
| | - James E. Saunders
- Department of Microbiology and Immunology, Dartmouth University, Hanover, New Hampshire
| | - Anping Xia
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Palo Alto, California
| | - Laurent A. Bekale
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Palo Alto, California
| | - Peter L. Santa Maria
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Palo Alto, California
| |
Collapse
|
3
|
Zhao YQ, Xia A, Zhang MH, Li JL, Zhu GD, Tang JX. [Microbiota structure and diversity in Aedes albopictus at different developmental stages]. Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi 2022; 34:475-483. [PMID: 36464263 DOI: 10.16250/j.32.1374.2022144] [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] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
OBJECTIVE To investigate the diversity and composition of microflora in laboratory-reared Aedes albopictus at different developmental stages and larval habitat waters. METHODS The larval habitat waters and different developmental stages of laboratory-reared A. albopictus were collected, and the V3 and V4 regions of the bacterial 16S rRNA gene were sequenced using Illumina Miseq next-generation sequencing. The abundance and diversity of the microflora were examined using alpha diversity index in A. albopictus at different developmental stages, and the difference in the microflora compositions was compared in A. albopictus at different developmental stages using principal component analysis (PCA). In addition, the species composition and relative abundance of microflora in A. albopictus at different developmental stages were described using histograms and Venn diagrams. RESULTS A total of 16 phyla, 30 classes, 72 orders, 129 families and 224 genera of bacteria were detected in larval habitat waters and different developmental stages of A. albopictus. The highest bacterial diversity was seen in larval A. albopictus, with Chao index of 125.20 ± 30.48 and Shannon diversity index of 2.04 ± 0.39, which were comparable to those (Chao index of 118.52 ± 15.07 and Shannon diversity index of 2.15 ± 0.30) in larval habitat waters (t = 0.35 and -0.41, both P values > 0.05). The bacterial abundance and evenness were significantly greater in female adults than in male adults (Chao index: 42.50 ± 3.54 vs. 18.50 ± 2.13, t = 8.23, P < 0.05; Shannon diversity index: 1.25 ± 1.67 vs. 0.50 ± 0.05, t = 6.00, P < 0.05). Proteobacteria, Bacteroidota, Actinobacteriota and Finnicutes were four common phyla of bacteria at each developmental stage of A. albopictus, with Proteobacteria dominated at the pupal stage (90.36%), Bacteroidota dominated at the adult stage (46.01% in female adults and 86.11% in male adults), and Actinobacteriota dominated at the larval stage (32.10%). Elizabethkingia and Rahnella 1 were common dominant genera of bacteria at each developmental stage of A. albopictus, with Rahnellal as the major component at the pupal stage (87.56%), Elizabethkingia as the main component at the adult stage (46.01% in female adults and 86.11% in male adults, respectively), and Microbacteria as the dominant bacterial genus at the larval stage (12.11%). In addition, Delftia, Elizabethkingia, Romboutsia, Serratia, Rahnella 1, Enterococcus and Microbacterium were common genera of bacteria at each developmental stage of A. albopictus, with Edaphobaculum dominated at the larval stage (17.54%) and Sphingobacterium dominated in larval habitat waters (13.93%). CONCLUSIONS There are differences in the composition of symbiotic bacteria at different developmental stages of A. albopictus; however, similar microflora diversity is maintained at the phylum level. The microflora diversity is comparable in larvae and larval habitat waters of A. albopictus.
Collapse
Affiliation(s)
- Y Q Zhao
- School of Public Health, Nanjing Medical University, Nanjing, Jiangsu 211166, China
- Key Laboratory of National Health Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu 214064, China
| | - A Xia
- School of Public Health, Nanjing Medical University, Nanjing, Jiangsu 211166, China
- Key Laboratory of National Health Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu 214064, China
| | - M H Zhang
- Key Laboratory of National Health Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu 214064, China
| | - J L Li
- Key Laboratory of National Health Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu 214064, China
| | - G D Zhu
- School of Public Health, Nanjing Medical University, Nanjing, Jiangsu 211166, China
- Key Laboratory of National Health Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu 214064, China
| | - J X Tang
- School of Public Health, Nanjing Medical University, Nanjing, Jiangsu 211166, China
- Key Laboratory of National Health Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu 214064, China
| |
Collapse
|
4
|
Xia A, Udagawa T, Quiñones PM, Atkinson PJ, Applegate BE, Cheng AG, Oghalai JS. The impact of targeted ablation of one row of outer hair cells and Deiters' cells on cochlear amplification. J Neurophysiol 2022; 128:1365-1373. [PMID: 36259670 PMCID: PMC9678430 DOI: 10.1152/jn.00501.2021] [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: 11/15/2021] [Revised: 10/13/2022] [Accepted: 10/17/2022] [Indexed: 11/22/2022] Open
Abstract
The mammalian cochlea contains three rows of outer hair cells (OHCs) that amplify the basilar membrane traveling wave with high gain and exquisite tuning. The pattern of OHC loss caused by typical methods of producing hearing loss in animal models (noise, ototoxic exposure, or aging) is variable and not consistent along the length of the cochlea. Thus, it is difficult to use these approaches to understand how forces from multiple OHCs summate to create normal cochlear amplification. Here, we selectively removed the third row of OHCs and Deiters' cells in adult mice and measured cochlear amplification. In the mature cochlear epithelia, expression of the Wnt target gene Lgr5 is restricted to the third row of Deiters' cells, the supporting cells directly underneath the OHCs. Diphtheria toxin administration to Lgr5DTR-EGFP/+ mice selectively ablated the third row of Deiters' cells and the third row of OHCs. Basilar membrane vibration in vivo demonstrated disproportionately lower reduction in cochlear amplification by about 13.5 dB. On a linear scale, this means that the 33% reduction in OHC number led to a 79% reduction in gain. Thus, these experimental data describe the impact of reducing the force of cochlear amplification by a specific amount. Furthermore, these data argue that because OHC forces progressively and sequentially amplify the traveling wave as it travels to its peak, the loss of even a relatively small number of OHCs, when evenly distributed longitudinally, will cause a substantial reduction in cochlear amplification.NEW & NOTEWORTHY Normal cochlear physiology involves force production from three rows of outer hair cells to amplify and tune the traveling wave. Here, we used a genetic approach to target and ablate the third row of outer hair cells in the mouse cochlea and found it reduced cochlear amplification by 79%. This means that the loss of even a relatively small number of OHCs, when evenly distributed, causes a substantial reduction in cochlear amplification.
Collapse
Affiliation(s)
- Anping Xia
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California
| | - Tomokatsu Udagawa
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California
- Department of Otorhinolaryngology, The Jikei University School of Medicine, Tokyo, Japan
| | - Patricia M Quiñones
- Caruso Department of Otolaryngology-Head & Neck Surgery, University of Southern California, Los Angeles, California
| | - Patrick J Atkinson
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California
| | - Brian E Applegate
- Caruso Department of Otolaryngology-Head & Neck Surgery, University of Southern California, Los Angeles, California
- Department of Biomedical Engineering, Denney Research Center (DRB) 140, University of Southern California, Los Angeles, California
| | - Alan G Cheng
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California
| | - John S Oghalai
- Caruso Department of Otolaryngology-Head & Neck Surgery, University of Southern California, Los Angeles, California
- Department of Biomedical Engineering, Denney Research Center (DRB) 140, University of Southern California, Los Angeles, California
| |
Collapse
|
5
|
Kashfi Sadabad R, Xia A, Benkafadar N, Faniku C, Preciado D, Yang S, Valdez TA. Topical Delivery of Elastic Liposomal Vesicles for Treatment of Middle and Inner Ear Diseases. ACS Appl Bio Mater 2022; 5:4849-4859. [PMID: 36179346 DOI: 10.1021/acsabm.2c00569] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We present a topical drug delivery mechanism through the ear canal to the middle and inner ear using liposomal nanoparticles without disrupting the integrity of the tympanic membrane. The current delivery method provides a noninvasive and safer alternative to transtympanic membrane injections, ear tubes followed by ear drops administration, and systemic drug formulations. We investigate the capability of liposomal NPs, particularly transfersomes (TLipo), used as drug delivery vesicles to penetrate the tympanic membrane (TM) and round window membrane (RWM) with high affinity, specificity, and retention time. The TLipo is applied to the ear canal and found to pass through the tympanic membrane quickly in 3 h post drug administration. They are identified in the middle ear cavity 6 h and in the inner ear 24 h after drug administration. We performed cytotoxicity in vitro and ototoxicity in vivo studies. Cell viability shows no significant difference between the applied TLipo concentration and control. Furthermore, auditory brainstem response (ABR) reveals no hearing loss in 1 week and 1 month post-administration. Immunohistochemistry results demonstrate no evidence of hair cell loss in the cochlea at 1 month following TLipo administration. Together, the data suggested that TLipo can be used as a vehicle for topical drug delivery to the middle ear and inner ear.
Collapse
Affiliation(s)
- Raana Kashfi Sadabad
- Department of Otolaryngology─Head & Neck Surgery Divisions, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Anping Xia
- Department of Otolaryngology─Head & Neck Surgery Divisions, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Nesrine Benkafadar
- Department of Otolaryngology─Head & Neck Surgery Divisions, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Chrysovalantou Faniku
- Department of Otolaryngology─Head & Neck Surgery Divisions, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Diego Preciado
- Division of Pediatric Otolaryngology, Children's National Health System, 111 Michigan Avenue NW, Washington, District of Columbia 20310, United States
| | - Stella Yang
- Department of Otolaryngology─Head & Neck Surgery Divisions, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Tulio A Valdez
- Department of Otolaryngology─Head & Neck Surgery Divisions, Stanford University School of Medicine, Stanford, California 94305, United States
| |
Collapse
|
6
|
Xia A, Thai A, Cao Z, Chen X, Chen J, Bacacao B, Bekale LA, Schiel V, Bollyky PL, Maria PLS. Chronic suppurative otitis media causes macrophage-associated sensorineural hearing loss. J Neuroinflammation 2022; 19:224. [PMID: 36096817 PMCID: PMC9465898 DOI: 10.1186/s12974-022-02585-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 08/23/2022] [Indexed: 11/10/2022] Open
Abstract
Background Chronic suppurative otitis media (CSOM) is the most common cause of permanent hearing loss in children in the developing world. A large component of the permanent hearing loss is sensory in nature and our understanding of the mechanism of this has so far been limited to post-mortem human specimens or acute infection models that are not representative of human CSOM. In this report, we assess cochlear injury in a validated Pseudomonas aeruginosa (PA) CSOM mouse model. Methods We generated persisters (PCs) and inoculated them into the mouse middle ear cavity. We tracked infection with IVIS and detected PA using RT-PCR. We assessed cochlear damage and innate immunity by Immunohistochemistry. Finally, we evaluated cytokines with multiplex assay and quantitative real-time PCR. Results We observed outer hair cell (OHC) loss predominantly in the basal turn of the cochlear at 14 days after bacterial inoculation. Macrophages, not neutrophils are the major immune cells in the cochlea in CSOM displaying increased numbers and a distribution correlated with the observed cochlear injury. The progression of the morphological changes suggests a transition from monocytes into tissue macrophages following infection. We also show that PA do not enter the cochlea and live bacteria are required for cochlear injury. We characterized cytokine activity in the CSOM cochlea. Conclusions Taken together, this data shows a critical role for macrophages in CSOM-mediated sensorineural hearing loss (SNHL). Supplementary Information The online version contains supplementary material available at 10.1186/s12974-022-02585-w.
Collapse
|
7
|
Cao Z, Chen X, Chen J, Xia A, Bacacao B, Tran J, Sharma D, Bekale LA, Santa Maria PL. Gold nanocluster adjuvant enables the eradication of persister cells by antibiotics and abolishes the emergence of resistance. Nanoscale 2022; 14:10016-10032. [PMID: 35796201 PMCID: PMC9578678 DOI: 10.1039/d2nr01003h] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Persister cells are responsible for relapses of infections common in cystic fibrosis and chronic suppurative otitis media (CSOM). Yet, there are no Food and Drug Administration (FDA) approved antibiotics to eradicate persister cells. Frustratingly, the global preclinical bacterial pipeline does not contain antibacterial agents targeting persister cells. Therefore, we report a nontraditional antimicrobial chemotherapy strategy based on gold nanoclusters adjuvant to eradicate persister cells by existing antibiotics belonging to that different class. Compared to killing with antibiotics alone, combining antibiotics and AuNC@CPP sterilizes persister cells and biofilms. Enhanced killing of up to 4 orders of magnitude in a validated mouse model of CSOM with Pseudomonas aeruginosa infection was observed when combining antibiotics and AuNC@CPP, informing a potential approach to improve the treatment of CSOM. We established that the mechanism of action of AuNC@CPP is due to disruption of the proton gradient and membrane hyperpolarization. The method presented here could compensate for the lack of new antibiotics to combat persister cells. This method could also benefit the current effort to slow resistance development because AuNC@CPP abolished the emergence of drug-resistant strains induced by antibiotics.
Collapse
Affiliation(s)
- Zhixin Cao
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA 94305-5739, USA.
- Department of Pathology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, China
| | - Xiaohua Chen
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA 94305-5739, USA.
- Department of Otolaryngology-Head and Neck Surgery, the First Affiliated Hospital, Zhengzhou University, Zhengzhou 450000, China
| | - Jing Chen
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA 94305-5739, USA.
| | - Anping Xia
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA 94305-5739, USA.
| | - Brian Bacacao
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA 94305-5739, USA.
| | - Jessica Tran
- The Protein and Nucleic Acid Biotechnology Facility, Beckman Center Stanford University, 279 Campus Drive, West Stanford, CA 94305, USA
| | - Devesh Sharma
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA 94305-5739, USA.
| | - Laurent A Bekale
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA 94305-5739, USA.
| | - Peter L Santa Maria
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA 94305-5739, USA.
| |
Collapse
|
8
|
Kouhi A, Xia A, Khomtchouk K, Santa Maria PL. Minimally invasive trans-tympanic eustachian tube occlusion animal model. Int J Pediatr Otorhinolaryngol 2022; 156:111070. [PMID: 35228098 DOI: 10.1016/j.ijporl.2022.111070] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 01/27/2022] [Accepted: 02/12/2022] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Eustachian tube dysfunction is believed to be involved in the pathogenesis of many middle ear diseases including chronic suppurative otitis media. We aimed to describe a simple and reliable animal model of Eustachian Tube obstruction to further research into middle ear disorders. STUDY DESIGN Prospective cohort study in animals. SETTING University laboratory. SUBJECTS AND METHODS 30 mice C57Bl/6J (n = 15) and CBA/CaJ (n = 15) aged 6-8 weeks received transtympanic Eustachian tube occlusion on left ear trough an acute tympanic membrane perforation using thermoplastic latex used in dental procedures (gutta percha). Control mice (n = 6) received tympanic membrane perforation only. At two and four weeks, the mice were observed for signs of Eustachian tube dysfunction and compared to control ears. ET dysfunction was defined as presence of effusion in the middle ear. RESULTS 100% (n = 30) of the treated ears had otoscopic signs of Eustachian tube dysfunction at two weeks and the endpoint time of four weeks, compared to 0% in control mice (0/6). Temporary head tilt lasting up to 2 days were observed in 3 mice (10%). No other potential adverse events were recorded. No bacterial growth was determined in the middle ear fluid. CONCLUSION We describe a technically easy and reliable method for Eustachian tube occlusion in mice with an excellent success rate and minimal morbidity.
Collapse
Affiliation(s)
- Ali Kouhi
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, USA; Otorhinolaryngology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Anping Xia
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, USA
| | - Kelly Khomtchouk
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, USA
| | - Peter Luke Santa Maria
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, USA.
| |
Collapse
|
9
|
Santa Maria PL, Kaufman AC, Bacacao B, Thai A, Chen X, Xia A, Cao Z, Fouad A, Bekale LA. Topical Therapy Failure in Chronic Suppurative Otitis Media is Due to Persister Cells in Biofilms. Otol Neurotol 2021; 42:e1263-e1272. [PMID: 34149028 DOI: 10.1097/mao.0000000000003222] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Chronic suppurative otitis media (CSOM) is characterized by a chronically draining middle ear. CSOM is typically treated with multiple courses of antibiotics or antiseptics which are successful in achieving quiescence; however, the disease is prone to relapse. Understanding why these treatment failures occur is essential. STUDY DESIGN The minimum inhibitory concentration (MIC), minimal biofilm eradication concentration, and the inhibitory zone were determined for ototopicals and ofloxacin for the laboratory strains and CSOM-derived isolates. The percentage of persister cells and bacterial biofilm formation were measured. Disease eradication was tested in a validated in-vivo model of CSOM after treatment with ofloxacin. SETTING Microbiology Laboratory. METHODS Basic science experiments were performed to measure the effectiveness of a number of compounds against CSOM bacteria in a number of distinct settings. RESULTS The minimal biofilm eradication concentration is higher than is physiologically achievable with commercial preparations, except for povo-iodine. Clincial isolates of CSOM have equivalent biofilm-forming ability but increased proportions of persister cells. Ofloxacin can convert to inactive disease temporarily but fails to eradicate disease in an in-vivo model. CONCLUSIONS Higher percentages of persister cells in clinical CSOM isolates are associated with resistance to ototopicals. Current ototopicals, except povo-iodine, have limited clinical effectiveness; however, it is unknown what the maximum achievable concentration is and there are ototoxicity concerns. Fluoroquinolones, while successful in producing inactive disease in the short term, have the potential to encourage antimicrobial resistance and disease recalcitrance and do not achieve a permanent remission. Given these limitations, clinicians should consider surgery earlier or use of clinically safe concentrations of povo-iodine earlier into the treatment algorithm.
Collapse
Affiliation(s)
- Peter L Santa Maria
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, California, USA
| | - Adam C Kaufman
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, California, USA
| | - Brian Bacacao
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, California, USA
| | - Anthony Thai
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, California, USA
| | - Xiaohua Chen
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, California, USA
- Department of Otolaryngology, Head and Neck Surgery, First Affiliated Hospital of Zhengzhou University, Henan, China
| | - Anping Xia
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, California, USA
| | - Zhixin Cao
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, California, USA
- Department of Pathology, Shandong Provincial Hospital Affiliated to Shandong University, Ji'nan, China
| | - Ayman Fouad
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, California, USA
- Department of Otolaryngology, Head and Neck Surgery, Tanta University, Tanta, Eqypt
| | - Laurent A Bekale
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, California, USA
| |
Collapse
|
10
|
Ding BJ, Liu L, Li MJ, Xia A, Song XW, Zhou KS, Zhou J, Xu PP, Liu JP, Zhou H, Song YP. [Cyclic thrombocytopenia: a case report and literature review]. Zhonghua Xue Ye Xue Za Zhi 2021; 42:770. [PMID: 34753235 PMCID: PMC8607038 DOI: 10.3760/cma.j.issn.0253-2727.2021.09.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- B J Ding
- Department of Hematology, Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou 450008, China
| | - L Liu
- Department of Hematology, First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - M J Li
- Department of Hematology, Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou 450008, China
| | - A Xia
- Department of Hematology, Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou 450008, China
| | - X W Song
- Department of Hematology, Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou 450008, China
| | - K S Zhou
- Department of Hematology, Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou 450008, China
| | - J Zhou
- Department of Hematology, Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou 450008, China
| | - P P Xu
- Department of Hematology, Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou 450008, China
| | - J P Liu
- Department of Hematology, Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou 450008, China
| | - H Zhou
- Department of Hematology, Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou 450008, China
| | - Y P Song
- Department of Hematology, Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou 450008, China
| |
Collapse
|
11
|
Liu X, Chen G, He J, Wan G, Shen D, Xia A, Chen F. Transcriptomic analysis reveals the inhibition of reproduction in rice brown planthopper, Nilaparvata lugens, after silencing the gene of MagR (IscA1). Insect Mol Biol 2021; 30:253-263. [PMID: 33410574 DOI: 10.1111/imb.12692] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 12/18/2020] [Accepted: 12/29/2020] [Indexed: 06/12/2023]
Abstract
MagR (IscA1) is a member of the iron-sulphur cluster assembly proteins, which plays vital roles in many physiological processes, such as energy metabolism, electron transfer, iron homeostasis, heme biosynthesis and physiologically magnetic response. Its deletion leads to the loss of mitochondrial DNA, inactivation of iron-sulphur proteins and abnormal embryonic development in organisms. However, the physiological roles of MagR in insects are unclear. This study characterized the effects and molecular regulatory mechanism of MagR gene silencing on the reproduction of brachypterous female adults of Nilaparvata lugens. After silencing the MagR gene using RNAi approach, the duration of reproductive period was shortened and the fecundity and hatchability reduced significantly. A total of 479 differentially expressed genes (DEGs) were identified for female adults after 2 days of dsRNA injection through RNA-sequencing technology, including 352 significantly upregulated DEGs and 127 significantly downregulated DEGs, among which 44 DEGs were considered the key genes involved in the effects of NlMagR silencing on the reproduction, revealing the regulatory mechanism of MagR at RNA transcription level and providing a new strategy for the control of N. lugens.
Collapse
Affiliation(s)
- X Liu
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - G Chen
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - J He
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - G Wan
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - D Shen
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - A Xia
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - F Chen
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| |
Collapse
|
12
|
Xu PP, Ding BJ, Li MJ, Liu JP, Liu L, Xia A, Liu WQ, Zhou KS, Zhao HF, Zhou H, Song YP. [Hereditary coagulation factor XIII deficiency: three cases report and literaure review]. Zhonghua Xue Ye Xue Za Zhi 2021; 42:256-258. [PMID: 33910314 PMCID: PMC8081941 DOI: 10.3760/cma.j.issn.0253-2727.2021.03.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- P P Xu
- Department of Hematology, The Affiliated Cancer Hospital of Zhengzhou University (Henan Cancer Hospital), Zhengzhou 450008, China
| | - B J Ding
- Department of Hematology, The Affiliated Cancer Hospital of Zhengzhou University (Henan Cancer Hospital), Zhengzhou 450008, China
| | - M J Li
- Department of Hematology, The Affiliated Cancer Hospital of Zhengzhou University (Henan Cancer Hospital), Zhengzhou 450008, China
| | - J P Liu
- Department of Hematology, The Affiliated Cancer Hospital of Zhengzhou University (Henan Cancer Hospital), Zhengzhou 450008, China
| | - L Liu
- Department of Hematology, First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - A Xia
- Department of Hematology, The Affiliated Cancer Hospital of Zhengzhou University (Henan Cancer Hospital), Zhengzhou 450008, China
| | - W Q Liu
- Department of Intensive Care Units, Henan Provincial People's Hospital, Zhengzhou 450003, China
| | - K S Zhou
- Department of Hematology, The Affiliated Cancer Hospital of Zhengzhou University (Henan Cancer Hospital), Zhengzhou 450008, China
| | - H F Zhao
- Department of Hematology, The Affiliated Cancer Hospital of Zhengzhou University (Henan Cancer Hospital), Zhengzhou 450008, China
| | - H Zhou
- Department of Hematology, The Affiliated Cancer Hospital of Zhengzhou University (Henan Cancer Hospital), Zhengzhou 450008, China
| | - Y P Song
- Department of Hematology, The Affiliated Cancer Hospital of Zhengzhou University (Henan Cancer Hospital), Zhengzhou 450008, China
| |
Collapse
|
13
|
Yim JJ, Singh SP, Xia A, Kashfi-Sadabad R, Tholen M, Huland DM, Zarabanda D, Cao Z, Solis-Pazmino P, Bogyo M, Valdez TA. Short-Wave Infrared Fluorescence Chemical Sensor for Detection of Otitis Media. ACS Sens 2020; 5:3411-3419. [PMID: 33175516 DOI: 10.1021/acssensors.0c01272] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Otitis media (OM) or middle ear infection is one of the most common diseases in young children around the world. The diagnosis of OM is currently performed using an otoscope to detect middle ear fluid and inflammatory changes manifested in the tympanic membrane. However, conventional otoscopy cannot visualize across the tympanic membrane or sample middle ear fluid. This can lead to low diagnostic certainty and overdiagnoses of OM. To improve the diagnosis of OM, we have developed a short-wave infrared (SWIR) otoscope in combination with a protease-cleavable biosensor, 6QC-ICG, which can facilitate the detection of inflammatory proteases in the middle ear with an increase in contrast. 6QC-ICG is a fluorescently quenched probe, which is activated in the presence of cysteine cathepsin proteases that are up-regulated in inflammatory immune cells. Using a preclinical model and custom-built SWIR otomicroscope in this proof-of-concept study, we successfully demonstrated the feasibility of robustly distinguishing inflamed ears from controls (p = 0.0006). The inflamed ears showed an overall signal-to-background ratio of 2.0 with a mean fluorescence of 81 ± 17 AU, while the control ear exhibited a mean fluorescence of 41 ± 11 AU. We envision that these fluorescently quenched probes in conjunction with SWIR imaging tools have the potential to be used as an alternate/adjunct tool for objective diagnosis of OM.
Collapse
Affiliation(s)
- Joshua J. Yim
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Surya Pratap Singh
- Department of Otolaryngology−Head & Neck Surgery Divisions, Stanford University School of Medicine, Stanford, California 94305, United States
- Department of Biosciences and Bioengineering, Indian Institute of Technology Dharwad, Dharwad, Karnataka 580011, India
| | - Anping Xia
- Department of Otolaryngology−Head & Neck Surgery Divisions, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Raana Kashfi-Sadabad
- Department of Otolaryngology−Head & Neck Surgery Divisions, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Martina Tholen
- Department of Pathology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - David M. Huland
- Molecular Imaging Program at Stanford, Department of Radiology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - David Zarabanda
- Department of Otolaryngology−Head & Neck Surgery Divisions, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Zhixin Cao
- Department of Otolaryngology−Head & Neck Surgery Divisions, Stanford University School of Medicine, Stanford, California 94305, United States
- Department of Pathology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China
| | - Paola Solis-Pazmino
- Department of Otolaryngology−Head & Neck Surgery Divisions, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Matthew Bogyo
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California 94305, United States
- Department of Pathology, Stanford University School of Medicine, Stanford, California 94305, United States
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Tulio A. Valdez
- Department of Otolaryngology−Head & Neck Surgery Divisions, Stanford University School of Medicine, Stanford, California 94305, United States
| |
Collapse
|
14
|
Chen J, Bekale LA, Khomtchouk KM, Xia A, Cao Z, Ning S, Knox SJ, Santa Maria PL. Locally administered heparin-binding epidermal growth factor-like growth factor reduces radiation-induced oral mucositis in mice. Sci Rep 2020; 10:17327. [PMID: 33060741 PMCID: PMC7567084 DOI: 10.1038/s41598-020-73875-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 09/21/2020] [Indexed: 01/28/2023] Open
Abstract
Oral mucositis refers to lesions of the oral mucosa observed in patients with cancer being treated with radiation with or without chemotherapy, and can significantly affect quality of life. There is a large unmet medical need to prevent oral mucositis that can occur with radiation either alone or in combination with chemotherapy. We investigated the efficacy of locally administered heparin-binding epidermal growth factor-like growth factor (HB-EGF), a potent epithelial proliferation and migration stimulator of the oral mucosa as a potential therapy to prevent radiation induced oral mucositis. Using a single dose (20 Gy) of radiation to the oral cavity of female C57BL/6 J mice, we evaluated the efficacy of HB-EGF treatment (5 µl of 10 µg/ml) solution. The results show that HB-EGF delivered post radiation, significantly increased the area of epithelial thickness on the tongue (dorsal tongue (42,106 vs 53,493 µm2, p < 0.01), ventral tongue (30,793 vs 39,095 µm2, *p < 0.05)) compared to vehicle control, enhanced new epithelial cell division, and increased the quality and quantity of desmosomes in the oral mucosa measured in the tongue and buccal mucosa. This data provides the proof of concept that local administration of HB-EGF has the potential to be developed as a topical treatment to mitigate oral mucositis following radiation.
Collapse
Affiliation(s)
- Jing Chen
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA, 94305-5739, USA
| | - Laurent A Bekale
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA, 94305-5739, USA.
| | - Kelly M Khomtchouk
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA, 94305-5739, USA
| | - Anping Xia
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA, 94305-5739, USA
| | - Zhixin Cao
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA, 94305-5739, USA
- Department of Pathology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021, Shandong, China
| | - Shoucheng Ning
- Department of Radiation Oncology, Stanford University, Stanford, CA, 94305, USA
| | - Susan J Knox
- Department of Radiation Oncology, Stanford University, Stanford, CA, 94305, USA
| | - Peter L Santa Maria
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA, 94305-5739, USA.
| |
Collapse
|
15
|
Khomtchouk KM, Kouhi A, Xia A, Bekale LA, Massa SM, Sweere JM, Pletzer D, Hancock RE, Bollyky PL, Santa Maria PL. A novel mouse model of chronic suppurative otitis media and its use in preclinical antibiotic evaluation. Sci Adv 2020; 6:eabc1828. [PMID: 32851190 PMCID: PMC7428333 DOI: 10.1126/sciadv.abc1828] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 07/02/2020] [Indexed: 05/06/2023]
Abstract
Chronic suppurative otitis media (CSOM) is a neglected pediatric disease affecting 330 million worldwide for which no new drugs have been introduced for over a decade. We developed a mouse model with utility in preclinical drug evaluation and antimicrobial discovery. Our model used immune-competent mice, tympanic membrane perforation and inoculation with luminescent Pseudomonas aeruginosa that enabled bacterial abundance tracking in real-time for 100 days. The resulting chronic infection exhibited hallmark features of clinical CSOM, including inhibition of tympanic membrane healing and purulent ear discharge. We evaluated the standard care fluoroquinolone ofloxacin and demonstrated that this therapy resulted in a temporary reduction of bacterial burden. These data are consistent with the clinical problem of persistent infection in CSOM and the need for therapeutic outcome measures that assess eradication post-therapeutic endpoint. We conclude that this novel mouse model of CSOM has value in investigating new potential therapies.
Collapse
Affiliation(s)
- Kelly M. Khomtchouk
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, CA, USA
| | - Ali Kouhi
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, CA, USA
- Department of Otolaryngology, Head and Neck Surgery, Tehran University of Medical Sciences, Tehran, Iran
| | - Anping Xia
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, CA, USA
| | - Laurent Adonis Bekale
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, CA, USA
| | - Solange M. Massa
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, CA, USA
| | - Jolien M. Sweere
- Department of Medicine, Infectious Diseases, Stanford University, Stanford, CA, USA
| | - Daniel Pletzer
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Robert E. Hancock
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Paul L. Bollyky
- Department of Medicine, Infectious Diseases, Stanford University, Stanford, CA, USA
| | - Peter L. Santa Maria
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, CA, USA
- Corresponding author.
| |
Collapse
|
16
|
Abstract
AIMS To use both quantitative and qualitative approaches to characterize the diabetes distress profile of Chinese-Canadians with Type 2 diabetes and to better understand their experience of living with diabetes. METHODS We recruited 40 Chinese-Canadian adults with Type 2 diabetes who completed a Mandarin- or Cantonese-language diabetes education programme in Richmond, British Columbia. Using a mixed-methods sequential explanatory research design, participants first completed a 15-item Chinese version of the Diabetes Distress Scale, which included three subscales: emotional burden, regimen-related distress, and physician distress. The self-report survey was followed by a semi-structured interview that addressed the following diabetes-related topics: perspectives towards the healthcare team, emotional health, diabetes-related concerns and stressors, diabetes diagnosis experience, and sources of social support and diabetes education. RESULTS The mean (sd) scores for total distress 1.5 (0.5), emotional burden 1.7 (0.7), regimen-related distress 1.4 (0.5), and physician distress 1.4 (0.9), fell within the 'low distress' range (< 2.0). Qualitative analysis of semi-structured interviews showed that some participants were dissatisfied with diabetes care providers and experienced emotional challenges, particularly early in their diagnosis. Other themes that emerged included eating distress, fear of complications, language barriers, and medication concerns. CONCLUSIONS Not only did the qualitative findings from semi-structured interviews capture aspects of diabetes distress that were not included in the quantitative survey, it also uncovered inconsistencies between the two datasets. To more accurately understand the diabetes distress experience of any ethnic community, both quantitative and qualitative approaches contribute unique value.
Collapse
Affiliation(s)
- A Xia
- School of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - K W Yau
- Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - T S Tang
- Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
17
|
Chen CA, Wang W, Pedersen SE, Raman A, Seymour ML, Ruiz FR, Xia A, van der Heijden ME, Wang L, Yin J, Lopez J, Rech ME, Lewis RA, Wu SM, Liu Z, Pereira FA, Pautler RG, Zoghbi HY, Schaaf CP. Nr2f1 heterozygous knockout mice recapitulate neurological phenotypes of Bosch-Boonstra-Schaaf optic atrophy syndrome and show impaired hippocampal synaptic plasticity. Hum Mol Genet 2020; 29:705-715. [PMID: 31600777 PMCID: PMC7104670 DOI: 10.1093/hmg/ddz233] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/17/2019] [Accepted: 09/23/2019] [Indexed: 01/08/2023] Open
Abstract
Bosch-Boonstra-Schaaf optic atrophy syndrome (BBSOAS) has been identified as an autosomal-dominant disorder characterized by a complex neurological phenotype, with high prevalence of intellectual disability and optic nerve atrophy/hypoplasia. The syndrome is caused by loss-of-function mutations in NR2F1, which encodes a highly conserved nuclear receptor that serves as a transcriptional regulator. Previous investigations to understand the protein's role in neurodevelopment have mostly used mouse models with constitutive and tissue-specific homozygous knockout of Nr2f1. In order to represent the human disease more accurately, which is caused by heterozygous NR2F1 mutations, we investigated a heterozygous knockout mouse model and found that this model recapitulates some of the neurological phenotypes of BBSOAS, including altered learning/memory, hearing defects, neonatal hypotonia and decreased hippocampal volume. The mice showed altered fear memory, and further electrophysiological investigation in hippocampal slices revealed significantly reduced long-term potentiation and long-term depression. These results suggest that a deficit or alteration in hippocampal synaptic plasticity may contribute to the intellectual disability frequently seen in BBSOAS. RNA-sequencing (RNA-Seq) analysis revealed significant differential gene expression in the adult Nr2f1+/- hippocampus, including the up-regulation of multiple matrix metalloproteases, which are known to be critical for the development and the plasticity of the nervous system. Taken together, our studies highlight the important role of Nr2f1 in neurodevelopment. The discovery of impaired hippocampal synaptic plasticity in the heterozygous mouse model sheds light on the pathophysiology of altered memory and cognitive function in BBSOAS.
Collapse
Affiliation(s)
- Chun-An Chen
- Department of Human and Molecular Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, USA
| | - Wei Wang
- Department of Human and Molecular Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, USA
| | - Steen E Pedersen
- Department of Molecular Physiology and Biophysics-Cardiovascular Sciences Track, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA
- Department of Physiology and Biochemistry, Ross University School of Medicine, Portsmouth, Commonwealth of Dominica
| | - Ayush Raman
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, USA
- Graduate Program in Quantitative and Computational Biosciences, Baylor College of Medicine, Houston, TX, USA
| | - Michelle L Seymour
- Huffington Center on Aging and Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Fernanda R Ruiz
- Huffington Center on Aging and Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Anping Xia
- Huffington Center on Aging and Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Meike E van der Heijden
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Li Wang
- Department of Human and Molecular Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, USA
| | - Jiani Yin
- Department of Human and Molecular Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, USA
| | - Joanna Lopez
- Department of Human and Molecular Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, USA
| | - Megan E Rech
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, USA
| | - Richard A Lewis
- Department of Human and Molecular Genetics, Baylor College of Medicine, Houston, TX, USA
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
| | - Samuel M Wu
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
| | - Zhandong Liu
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Fred A Pereira
- Huffington Center on Aging and Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Robia G Pautler
- Department of Molecular Physiology and Biophysics-Cardiovascular Sciences Track, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA
| | - Huda Y Zoghbi
- Department of Human and Molecular Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX, USA
| | - Christian P Schaaf
- Department of Human and Molecular Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, USA
- Institute of Human Genetics, Heidelberg University, Heidelberg, Germany
| |
Collapse
|
18
|
Dewey JB, Xia A, Müller U, Belyantseva IA, Applegate BE, Oghalai JS. Mammalian Auditory Hair Cell Bundle Stiffness Affects Frequency Tuning by Increasing Coupling along the Length of the Cochlea. Cell Rep 2019; 23:2915-2927. [PMID: 29874579 PMCID: PMC6309882 DOI: 10.1016/j.celrep.2018.05.024] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 04/24/2018] [Accepted: 05/08/2018] [Indexed: 01/15/2023] Open
Abstract
The stereociliary bundles of cochlear hair cells convert mechanical vibrations into the electrical signals required for auditory sensation. While the stiffness of the bundles strongly influences mechanotransduction, its influence on the vibratory response of the cochlear partition is unclear. To assess this, we measured cochlear vibrations in mutant mice with reduced bundle stiffness or with a tectorial membrane (TM) that is detached from the sensory epithelium. We found that reducing bundle stiffness decreased the high-frequency extent and sharpened the tuning of vibratory responses obtained postmortem. Detaching the TM further reduced the high-frequency extent of the vibrations but also lowered the partition’s resonant frequency. Together, these results demonstrate that the bundle’s stiffness and attachment to the TM contribute to passive longitudinal coupling in the cochlea. We conclude that the stereociliary bundles and TM interact to facilitate passive wave propagation to more apical locations, possibly enhancing active wave amplification in vivo. The mechanical properties of the cochlear partition determine its vibratory response to sound. Dewey et al. demonstrate that the outer hair cell stereociliary bundles’ stiffness and attachment to the tectorial membrane influence the partition’s passive vibratory response. The stereociliary bundles facilitate the propagation of cochlear waves to more apical regions.
Collapse
Affiliation(s)
- James B Dewey
- The Caruso Department of Otolaryngology - Head & Neck Surgery, University of Southern California, Los Angeles, CA 90033, USA
| | - Anping Xia
- Department of Otolaryngology - Head & Neck Surgery, Stanford University, Stanford, CA 94305, USA
| | - Ulrich Müller
- The Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
| | | | - Brian E Applegate
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
| | - John S Oghalai
- The Caruso Department of Otolaryngology - Head & Neck Surgery, University of Southern California, Los Angeles, CA 90033, USA.
| |
Collapse
|
19
|
Singh SP, Xia A, Tusty M, Victorovich Malkovskiy A, Easwaran M, Zarabanda D, Valdez TA. Identification of early inflammatory changes in the tympanic membrane with Raman spectroscopy. Analyst 2019; 144:6721-6728. [PMID: 31612878 DOI: 10.1039/c9an01772k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The tympanic membrane (TM) is a dynamic structure that separates the middle ear from the external auditory canal. It is also integral for the transmission of sound waves. In this study, we demonstrate the feasibility of using Raman spectroscopy to identify early chemical changes resulting from inflammation in the TM that can serve as an indicator of acute otitis media. Bacterial lipopolysaccharide (LPS) was injected trans-tympanicaly in a murine model. Presence of inflammatory response was assessed with binocular microscopy, confirmed with histopathology and immunofluorescence staining. Successful discrimination suggesting spectral differences among the control and LPS treated groups was achieved using principal component analysis. Raman imaging revealed major differences in collagen distribution and nucleic acid content. Image segmentation analysis on the trichrome stained tissue sections was performed to corroborate the Raman spectra. The spectral co-localization study suggests changes in the expression of collagen IV specific signals in LPS treated samples. The overall findings of the study support prospective application of RS in the diagnosis and therapeutic monitoring of otitis media.
Collapse
Affiliation(s)
- S P Singh
- Department of Otolaryngology and Head and Neck Surgery, School of Medicine, Stanford University, Palo Alto, CA 94305, USA.
| | - Anping Xia
- Department of Otolaryngology and Head and Neck Surgery, School of Medicine, Stanford University, Palo Alto, CA 94305, USA.
| | - Mahbuba Tusty
- Department of Otolaryngology and Head and Neck Surgery, School of Medicine, Stanford University, Palo Alto, CA 94305, USA.
| | | | - Meena Easwaran
- Department of Otolaryngology and Head and Neck Surgery, School of Medicine, Stanford University, Palo Alto, CA 94305, USA.
| | - David Zarabanda
- Department of Otolaryngology and Head and Neck Surgery, School of Medicine, Stanford University, Palo Alto, CA 94305, USA.
| | - Tulio A Valdez
- Department of Otolaryngology and Head and Neck Surgery, School of Medicine, Stanford University, Palo Alto, CA 94305, USA.
| |
Collapse
|
20
|
Ma RQ, Xia A, Zhai XC, Chen F, Xu HB. [A single-center clinical analysis of 65 cases of pseudomyxoma peritonei from appendiceal origin in the early stage]. Zhonghua Zhong Liu Za Zhi 2019; 41:698-702. [PMID: 31550861 DOI: 10.3760/cma.j.issn.0253-3766.2019.09.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To analyze the efficacy and safety of cytoreduction surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) for pseudomyxoma peritonei (PMP) in the early stage. Methods: The clinical data, including pathological features, recurrence and survival of 65 PMP patients in the early stage underwent CRS combined with HIPEC in Aerospace Center Hospital from January, 2011 to December, 2018 were retrospectively analyzed. Results: 65 patients with early stage PMP underwent CRS+ HIPEC. Among these patients, 25 were males and 40 were females, and the mean age was 52.5 years. The median peritoneal cancer index was 3 (0-16). The score of completeness of cytoreduction (CC) of 63 patients (96.9%) was 0, and 2 patients (3.1%) was 1. No perioperative death occurred, the incidence of surgical complications above grade 3 was 3.1%. Three patients relapsed during the follow-up period, including 1 patient with low-grade PMP, 1 patient with high-grade PMP, and 1 patient with high-grade PMP accompanied by signet ring cell. The 5-year disease-free survival rate of the whole group was 92.4%. Conclusions: PMP patients in the early stage treated by CRS combined with HIPEC can achieve benefit and safety. A close long-term follow-up is necessary.
Collapse
Affiliation(s)
- R Q Ma
- Department of myxoma, Aerospace Central Hospital, Beijing 100049, China
| | | | | | | | | |
Collapse
|
21
|
Mohammadjavadi M, Ye PP, Xia A, Brown J, Popelka G, Pauly KB. Elimination of peripheral auditory pathway activation does not affect motor responses from ultrasound neuromodulation. Brain Stimul 2019; 12:901-910. [PMID: 30880027 DOI: 10.1016/j.brs.2019.03.005] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Revised: 01/28/2019] [Accepted: 03/04/2019] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Recent studies in a variety of animal models including rodents, monkeys, and humans suggest that transcranial focused ultrasound (tFUS) has considerable promise for non-invasively modulating neural activity with the ability to target deep brain structures. However, concerns have been raised that motor responses evoked by tFUS may be due to indirect activation of the auditory pathway rather than direct activation of motor circuits. OBJECTIVE In this study, we sought to examine the involvement of peripheral auditory system activation from tFUS stimulation applied to elicit motor responses. The purpose was to determine to what extent ultrasound induced auditory artifact could be a factor in ultrasound motor neuromodulation. METHODS In this study, tFUS-induced electromyography (EMG) signals were recorded and analyzed in wild-type (WT) normal hearing mice and two strains of genetically deaf mice to examine the involvement of the peripheral auditory system in tFUS-stimulated motor responses. In addition, auditory brainstem responses (ABRs) were measured to elucidate the effect of the tFUS stimulus envelope on auditory and motor responses. We also varied the tFUS stimulation duration to measure its effect on motor response duration. RESULTS We show, first, that the sharp edges in a tFUS rectangular envelope stimulus activate the peripheral afferent auditory pathway and, second, that smoothing these edges eliminates the auditory responses without affecting the motor responses in normal hearing WT mice. We further show that by eliminating peripheral auditory activity using two different strains of deaf knockout mice, motor responses are the same as in normal hearing WT mice. Finally, we demonstrate a high correlation between tFUS pulse duration and EMG response duration. CONCLUSION These results support the concept that tFUS-evoked motor responses are not a result of stimulation of the peripheral auditory system.
Collapse
Affiliation(s)
| | | | - Anping Xia
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, CA, USA
| | - Julian Brown
- Howard Hughes Medical Institute, Department of Neurobiology, Stanford University, Stanford, CA, USA
| | - Gerald Popelka
- Department of Radiology, Stanford University, Stanford, CA, USA; Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, CA, USA
| | - Kim Butts Pauly
- Department of Radiology, Stanford University, Stanford, CA, USA; Department of Bioengineering, Stanford University, Stanford, CA, USA; Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| |
Collapse
|
22
|
|
23
|
Dong W, Xia A, Raphael PD, Puria S, Applegate B, Oghalai JS. Organ of Corti vibration within the intact gerbil cochlea measured by volumetric optical coherence tomography and vibrometry. J Neurophysiol 2018; 120:2847-2857. [PMID: 30281386 DOI: 10.1152/jn.00702.2017] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
There is indirect evidence that the mammalian cochlea in the low-frequency apical and the more commonly studied high-frequency basal regions function in fundamentally different ways. Here, we directly tested this hypothesis by measuring sound-induced vibrations of the organ of Corti (OoC) at three turns of the gerbil cochlea using volumetric optical coherence tomography vibrometry (VOCTV), an approach that permits noninvasive imaging through the bone. In the apical turn, there was little frequency selectivity, and the displacement-vs.-frequency curves had low-pass filter characteristics with a corner frequency of ~0.5-0.9 kHz. The vibratory magnitudes increased compressively with increasing stimulus intensity at all frequencies. In the middle turn, responses were similar except for a slight peak in the response at ~2.5 kHz. The gain was ~50 dB at the peak and 30-40 dB at lower frequencies. In the basal turn, responses were sharply tuned and compressively nonlinear, consistent with observations in the literature. These data demonstrated that there is a transition of the mechanical response of the OoC along the length of the cochlea such that frequency tuning is sharper in the base than in the apex. Because the responses are fundamentally different, it is not appropriate to simply frequency shift vibratory data measured at one cochlear location to predict the cochlear responses at other locations. Furthermore, this means that the number of hair cells stimulated by sound is larger for low-frequency stimuli and smaller for high-frequency stimuli for the same intensity level. Thus the mechanisms of central processing of sounds must vary with frequency. NEW & NOTEWORTHY A volumetric optical coherence tomography and vibrometry system was used to probe cochlear mechanics within the intact gerbil cochlea. We found a gradual transition of the mechanical response of the organ of Corti along the length of the cochlea such that tuning at the base is dramatically sharper than that at the apex. These data help to explain discrepancies in the literature regarding how the cochlea processes low-frequency sounds.
Collapse
Affiliation(s)
- Wei Dong
- VA Loma Linda Healthcare System, Loma Linda, California.,Department of Otolaryngology - Head and Neck Surgery, Loma Linda University Health , Loma Linda, California
| | - Anping Xia
- Department of Otolaryngology - Head and Neck Surgery, Stanford University , Stanford, California
| | - Patrick D Raphael
- Department of Otolaryngology - Head and Neck Surgery, Stanford University , Stanford, California
| | - Sunil Puria
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary and Harvard Medical School , Boston, Massachusetts
| | - Brian Applegate
- Department of Biomedical Engineering, Texas A&M University , College Station, Texas
| | - John S Oghalai
- Caruso Department of Otolaryngology - Head and Neck Surgery, University of Southern California , Los Angeles, California
| |
Collapse
|
24
|
Abstract
Traumatic noise causes hearing loss by damaging sensory hair cells and their auditory synapses. There are no treatments. Here, we investigated mice exposed to a blast wave approximating a roadside bomb. In vivo cochlear imaging revealed an increase in the volume of endolymph, the fluid within scala media, termed endolymphatic hydrops. Endolymphatic hydrops, hair cell loss, and cochlear synaptopathy were initiated by trauma to the mechanosensitive hair cell stereocilia and were K+-dependent. Increasing the osmolality of the adjacent perilymph treated endolymphatic hydrops and prevented synaptopathy, but did not prevent hair cell loss. Conversely, inducing endolymphatic hydrops in control mice by lowering perilymph osmolality caused cochlear synaptopathy that was glutamate-dependent, but did not cause hair cell loss. Thus, endolymphatic hydrops is a surrogate marker for synaptic bouton swelling after hair cells release excitotoxic levels of glutamate. Because osmotic stabilization prevents neural damage, it is a potential treatment to reduce hearing loss after noise exposure.
Collapse
Affiliation(s)
- Jinkyung Kim
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, CA 94305
| | - Anping Xia
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, CA 94305
| | - Nicolas Grillet
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, CA 94305
| | - Brian E Applegate
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843
| | - John S Oghalai
- Caruso Department of Otolaryngology-Head and Neck Surgery, University of Southern California, Los Angeles, CA 90033
| |
Collapse
|
25
|
Barbour AD, Luczak MJ, Xia A. Multivariate approximation in total variation, I: Equilibrium distributions of Markov jump processes. ANN PROBAB 2018. [DOI: 10.1214/17-aop1204] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
26
|
|
27
|
Xia A, Liu X, Raphael PD, Applegate BE, Oghalai JS. Hair cell force generation does not amplify or tune vibrations within the chicken basilar papilla. Nat Commun 2016; 7:13133. [PMID: 27796310 PMCID: PMC5095595 DOI: 10.1038/ncomms13133] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 09/07/2016] [Indexed: 12/22/2022] Open
Abstract
Frequency tuning within the auditory papilla of most non-mammalian species is electrical, deriving from ion-channel resonance within their sensory hair cells. In contrast, tuning within the mammalian cochlea is mechanical, stemming from active mechanisms within outer hair cells that amplify the basilar membrane travelling wave. Interestingly, hair cells in the avian basilar papilla demonstrate both electrical resonance and force-generation, making it unclear which mechanism creates sharp frequency tuning. Here, we measured sound-induced vibrations within the apical half of the chicken basilar papilla in vivo and found broadly-tuned travelling waves that were not amplified. However, distortion products were found in live but not dead chickens. These findings support the idea that avian hair cells do produce force, but that their effects on vibration are small and do not sharpen tuning. Therefore, frequency tuning within the apical avian basilar papilla is not mechanical, and likely derives from hair cell electrical resonance. The avian auditory papilla has many similarities to the mammalian cochlea but whether force generation by hair cells amplifies the travelling wave, as it does in mammals, remains unknown. Here the authors show that the chicken basilar papilla does not have a ‘cochlear amplifier' and that sharp frequency tuning does not derive from mechanical vibrations.
Collapse
Affiliation(s)
- Anping Xia
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, California 94305, USA
| | - Xiaofang Liu
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, California 94305, USA.,Department of Anorectal Surgery, the First Affiliated hospital of China Medical University, 155 NanjingBei Street, ShenYang, LiaoNing Province 110001, China
| | - Patrick D Raphael
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, California 94305, USA
| | - Brian E Applegate
- Department of Biomedical Engineering, Texas A&M University, 5059 Emerging Technology Building, 3120 TAMU, College Station, Texas 77843, USA
| | - John S Oghalai
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, California 94305, USA
| |
Collapse
|
28
|
Chen K, Wang X, Zhang L, Xia A, Chen F, Wang J. P-174CLINICAL FEATURES AND PROGNOSIS OF PATIENTS WITH DIFFERENT CHARACTERISTIC LUNG CANCERS AS THE SECONDARY PRIMARY MALIGNANCY. Interact Cardiovasc Thorac Surg 2016. [DOI: 10.1093/icvts/ivw260.172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
29
|
Abstract
Empirical point processes of exceedances play an important role in extreme value theory, and their limiting behaviour has been extensively studied. Here, we provide explicit bounds on the accuracy of approximating an exceedance process by a compound Poisson or Poisson cluster process, in terms of a Wasserstein metric that is generally more suitable for the purpose than the total variation metric. The bounds only involve properties of the finite, empirical sequence that is under consideration, and not of any limiting process. The argument uses Bernstein blocks and Lindeberg's method of compositions.
Collapse
|
30
|
Abstract
Let n points be placed uniformly at random in a subset A of the plane. A point is said to be maximal in the configuration if no other point is larger in both coordinates. We show that, for large n and for many sets A, the number of maximal points is approximately normally distributed. The argument uses Stein's method, and is also applicable in higher dimensions.
Collapse
|
31
|
Heckel A, Weiler M, Xia A, Ruetters M, Pham M, Bendszus M, Heiland S, Baeumer P. Peripheral Nerve Diffusion Tensor Imaging: Assessment of Axon and Myelin Sheath Integrity. PLoS One 2015; 10:e0130833. [PMID: 26114630 PMCID: PMC4482724 DOI: 10.1371/journal.pone.0130833] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 05/26/2015] [Indexed: 12/15/2022] Open
Abstract
Purpose To investigate the potential of diffusion tensor imaging (DTI) parameters as in-vivo biomarkers of axon and myelin sheath integrity of the median nerve in the carpal tunnel as validated by correlation with electrophysiology. Methods MRI examinations at 3T including DTI were conducted on wrists in 30 healthy subjects. After manual segmentation of the median nerve quantitative analysis of fractional anisotropy (FA) as well as axial, radial and mean diffusivity (AD, RD, and MD) was carried out. Pairwise Pearson correlations with electrophysiological parameters comprising sensory nerve action potential (SNAP) and compound muscle action potential (CMAP) as markers of axon integrity, and distal motor latency (dml) and sensory nerve conduction velocity (sNCV) as markers of myelin sheath integrity were computed. The significance criterion was set at P=0.05, Bonferroni corrected for multiple comparisons. Results DTI parameters showed a distinct proximal-to-distal profile with FA, MD, and RD extrema coinciding in the center of the carpal tunnel. AD correlated with CMAP (r=0.50, p=0.04, Bonf. corr.) but not with markers of myelin sheath integrity. RD correlated with sNCV (r=-0.53, p=0.02, Bonf. corr.) but not with markers of axon integrity. FA correlated with dml (r=-0.63, p=0.002, Bonf. corr.) and sNCV (r=0.68, p=0.001, Bonf. corr.) but not with markers of axon integrity. Conclusion AD reflects axon integrity, while RD (and FA) reflect myelin sheath integrity as validated by correlation with electrophysiology. DTI parameters consistently indicate a slight decrease of structural integrity in the carpal tunnel as a physiological site of median nerve entrapment. DTI is particularly sensitive, since these findings are observed in healthy participants. Our results encourage future studies to evaluate the potential of DTI in differentiating axon from myelin sheath injury in patients with manifest peripheral neuropathies.
Collapse
Affiliation(s)
- A Heckel
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany; Department of Diagnostic Radiology, Freiburg University Hospital, Freiburg, Germany
| | - M Weiler
- Department of Neurology, Heidelberg University Hospital, Heidelberg, Germany; Clinical Cooperation Unit Neurooncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - A Xia
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - M Ruetters
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - M Pham
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - M Bendszus
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - S Heiland
- Section of Experimental Neuroradiology, Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - P Baeumer
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| |
Collapse
|
32
|
|
33
|
Bäumer P, Xia A, Weiler M, Heckel A, Schwarz D, Pham M, Jäger D, Bendszus M, Apostolidis L. Oxaliplatin-induzierte Polyneuropathie: Detektion und quantitative Charakterisierung der Pathophysiologie mittels MR Neurografie. ROFO-FORTSCHR RONTG 2015. [DOI: 10.1055/s-0035-1550764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
34
|
Bäumer P, Xia A, Kele H, Dombert T, Staub F, Bendszus M, Pham M. Interosseus-posterior-Neuropathie: Proximale faszikulär-inflammatorische Läsion versus fokale Kompression. ROFO-FORTSCHR RONTG 2015. [DOI: 10.1055/s-0035-1551244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
35
|
Maass JC, Gu R, Basch ML, Waldhaus J, Lopez EM, Xia A, Oghalai JS, Heller S, Groves AK. Changes in the regulation of the Notch signaling pathway are temporally correlated with regenerative failure in the mouse cochlea. Front Cell Neurosci 2015; 9:110. [PMID: 25873862 PMCID: PMC4379755 DOI: 10.3389/fncel.2015.00110] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 03/10/2015] [Indexed: 12/20/2022] Open
Abstract
Sensorineural hearing loss is most commonly caused by the death of hair cells in the organ of Corti, and once lost, mammalian hair cells do not regenerate. In contrast, other vertebrates such as birds can regenerate hair cells by stimulating division and differentiation of neighboring supporting cells. We currently know little of the genetic networks which become active in supporting cells when hair cells die and that are activated in experimental models of hair cell regeneration. Several studies have shown that neonatal mammalian cochlear supporting cells are able to trans-differentiate into hair cells when cultured in conditions in which the Notch signaling pathway is blocked. We now show that the ability of cochlear supporting cells to trans-differentiate declines precipitously after birth, such that supporting cells from six-day-old mouse cochlea are entirely unresponsive to a blockade of the Notch pathway. We show that this trend is seen regardless of whether the Notch pathway is blocked with gamma secretase inhibitors, or by antibodies against the Notch1 receptor, suggesting that the action of gamma secretase inhibitors on neonatal supporting cells is likely to be by inhibiting Notch receptor cleavage. The loss of responsiveness to inhibition of the Notch pathway in the first postnatal week is due in part to a down-regulation of Notch receptors and ligands, and we show that this down-regulation persists in the adult animal, even under conditions of noise damage. Our data suggest that the Notch pathway is used to establish the repeating pattern of hair cells and supporting cells in the organ of Corti, but is not required to maintain this cellular mosaic once the production of hair cells and supporting cells is completed. Our results have implications for the proposed used of Notch pathway inhibitors in hearing restoration therapies.
Collapse
Affiliation(s)
- Juan C Maass
- Department of Neuroscience, Baylor College of Medicine Houston, TX, USA ; Department of Otolaryngology, Hospital Clínico Universidad de Chile Santiago, Chile ; Interdisciplinary Program of Physiology and Biophysics, ICBM Universidad de Chile Santiago, Chile ; Department of Otolaryngology, Clínica Alemana de Santiago, Facultad de Medicina Clínica Alemana-Universidad del Desarrollo Santiago, Chile
| | - Rende Gu
- Department of Neuroscience, Baylor College of Medicine Houston, TX, USA
| | - Martin L Basch
- Department of Neuroscience, Baylor College of Medicine Houston, TX, USA
| | - Joerg Waldhaus
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine Palo Alto, CA, USA
| | | | - Anping Xia
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine Palo Alto, CA, USA
| | - John S Oghalai
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine Palo Alto, CA, USA
| | - Stefan Heller
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine Palo Alto, CA, USA
| | - Andrew K Groves
- Department of Neuroscience, Baylor College of Medicine Houston, TX, USA ; Department of Molecular and Human Genetics, Baylor College of Medicine Houston, TX, USA ; Program in Developmental Biology, Baylor College of Medicine Houston, TX, USA
| |
Collapse
|
36
|
Song Y, Xia A, Lee HY, Wang R, Ricci AJ, Oghalai JS. Activity-dependent regulation of prestin expression in mouse outer hair cells. J Neurophysiol 2015; 113:3531-42. [PMID: 25810486 DOI: 10.1152/jn.00869.2014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 03/19/2015] [Indexed: 12/11/2022] Open
Abstract
Prestin is a membrane protein necessary for outer hair cell (OHC) electromotility and normal hearing. Its regulatory mechanisms are unknown. Several mouse models of hearing loss demonstrate increased prestin, inspiring us to investigate how hearing loss might feedback onto OHCs. To test whether centrally mediated feedback regulates prestin, we developed a novel model of inner hair cell loss. Injection of diphtheria toxin (DT) into adult CBA mice produced significant loss of inner hair cells without affecting OHCs. Thus, DT-injected mice were deaf because they had no afferent auditory input despite OHCs continuing to receive normal auditory mechanical stimulation and having normal function. Patch-clamp experiments demonstrated no change in OHC prestin, indicating that loss of information transfer centrally did not alter prestin expression. To test whether local mechanical feedback regulates prestin, we used Tecta(C1509G) mice, where the tectorial membrane is malformed and only some OHCs are stimulated. OHCs connected to the tectorial membrane had normal prestin levels, whereas OHCs not connected to the tectorial membrane had elevated prestin levels, supporting an activity-dependent model. To test whether the endocochlear potential was necessary for prestin regulation, we studied Tecta(C1509G) mice at different developmental ages. OHCs not connected to the tectorial membrane had lower than normal prestin levels before the onset of the endocochlear potential and higher than normal prestin levels after the onset of the endocochlear potential. Taken together, these data indicate that OHC prestin levels are regulated through local feedback that requires mechanoelectrical transduction currents. This adaptation may serve to compensate for variations in the local mechanical environment.
Collapse
Affiliation(s)
- Yohan Song
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, California
| | - Anping Xia
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, California
| | - Hee Yoon Lee
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, California
| | - Rosalie Wang
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, California
| | - Anthony J Ricci
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, California
| | - John S Oghalai
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, California
| |
Collapse
|
37
|
Liang J, Sharakhova MV, Lan Q, Zhu H, Sharakhov IV, Xia A. A standard cytogenetic map for Anopheles sinensis and chromosome arm homology between the subgenera Anopheles and Cellia. Med Vet Entomol 2014; 28 Suppl 1:26-32. [PMID: 25171604 PMCID: PMC4156234 DOI: 10.1111/mve.12048] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 11/21/2013] [Accepted: 11/26/2013] [Indexed: 06/03/2023]
Abstract
Anopheles sinensis (Diptera: Culicidae) is an important vector of Plasmodium vivax in Southeast Asia. To facilitate population genetic and genomic studies of An. sinensis, we developed a standard cytogenetic photomap for this species. The polytene chromosomes were straightened and divided into 39 numbered divisions and 116 lettered subdivisions. The chromosomal localizations of 13 DNA probes were determined by fluorescent in situ hybridization. A comparison of the physical map for An. sinensis with the genome map for Anopheles gambiae revealed a whole-arm autosomal translocation between the two species. Specifically, the 2R arm of An. gambiae corresponds to the 3R arm of An. sinensis and the pattern of correspondence of the other chromosome arms remains regular. We mapped the breakpoints of the polymorphic paracentric chromosomal inversion 3Ra to subdivisions 28A and 31A. The standard cytogenetic map developed in this study will be useful for detailed comparative genome mapping and population genetic studies of An. sinensis.
Collapse
Affiliation(s)
- J Liang
- Department of Entomology, Nanjing Agricultural University, Nanjing, China
| | | | | | | | | | | |
Collapse
|
38
|
Xia A, Song Y, Wang R, Gao SS, Clifton W, Raphael P, Chao SI, Pereira FA, Groves AK, Oghalai JS. Prestin regulation and function in residual outer hair cells after noise-induced hearing loss. PLoS One 2013; 8:e82602. [PMID: 24376553 PMCID: PMC3869702 DOI: 10.1371/journal.pone.0082602] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 10/25/2013] [Indexed: 12/27/2022] Open
Abstract
The outer hair cell (OHC) motor protein prestin is necessary for electromotility, which drives cochlear amplification and produces exquisitely sharp frequency tuning. TectaC1509G transgenic mice have hearing loss, and surprisingly have increased OHC prestin levels. We hypothesized, therefore, that prestin up-regulation may represent a generalized response to compensate for a state of hearing loss. In the present study, we sought to determine the effects of noise-induced hearing loss on prestin expression. After noise exposure, we performed cytocochleograms and observed OHC loss only in the basal region of the cochlea. Next, we patch clamped OHCs from the apical turn (9–12 kHz region), where no OHCs were lost, in noise-exposed and age-matched control mice. The non-linear capacitance was significantly higher in noise-exposed mice, consistent with higher functional prestin levels. We then measured prestin protein and mRNA levels in whole-cochlea specimens. Both Western blot and qPCR studies demonstrated increased prestin expression after noise exposure. Finally, we examined the effect of the prestin increase in vivo following noise damage. Immediately after noise exposure, ABR and DPOAE thresholds were elevated by 30–40 dB. While most of the temporary threshold shifts recovered within 3 days, there were additional improvements over the next month. However, DPOAE magnitudes, basilar membrane vibration, and CAP tuning curve measurements from the 9–12 kHz cochlear region demonstrated no differences between noise-exposed mice and control mice. Taken together, these data indicate that prestin is up-regulated by 32–58% in residual OHCs after noise exposure and that the prestin is functional. These findings are consistent with the notion that prestin increases in an attempt to partially compensate for reduced force production because of missing OHCs. However, in regions where there is no OHC loss, the cochlea is able to compensate for the excess prestin in order to maintain stable auditory thresholds and frequency discrimination.
Collapse
MESH Headings
- Animals
- Cochlear Microphonic Potentials
- Evoked Potentials, Auditory, Brain Stem
- Gene Expression Regulation
- Hair Cells, Auditory, Outer/metabolism
- Hair Cells, Auditory, Outer/pathology
- Hearing Loss, Noise-Induced/metabolism
- Hearing Loss, Noise-Induced/pathology
- Hearing Loss, Noise-Induced/physiopathology
- Mice
- Models, Biological
- Molecular Motor Proteins/genetics
- Molecular Motor Proteins/metabolism
- Noise
- Otoacoustic Emissions, Spontaneous
- Patch-Clamp Techniques
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
Collapse
Affiliation(s)
- Anping Xia
- Department of Otolaryngology–Head and Neck Surgery, Stanford University, Stanford, California, United States of America
| | - Yohan Song
- Department of Otolaryngology–Head and Neck Surgery, Stanford University, Stanford, California, United States of America
| | - Rosalie Wang
- Department of Otolaryngology–Head and Neck Surgery, Stanford University, Stanford, California, United States of America
| | - Simon S. Gao
- Department of Otolaryngology–Head and Neck Surgery, Stanford University, Stanford, California, United States of America
- Department of Bioengineering, Rice University, Houston, Texas, United States of America
| | - Will Clifton
- Bobby R. Alford Department of Otolaryngology – Head and Neck Surgery, Baylor College of Medicine, Houston, Texas, United States of America
| | - Patrick Raphael
- Department of Otolaryngology–Head and Neck Surgery, Stanford University, Stanford, California, United States of America
| | - Sung-il Chao
- Department of Otolaryngology–Head and Neck Surgery, Stanford University, Stanford, California, United States of America
- Department of Otolaryngology–Head and Neck Surgery, Chosun University, Gwangju, South Korea
| | - Fred A. Pereira
- Bobby R. Alford Department of Otolaryngology – Head and Neck Surgery, Baylor College of Medicine, Houston, Texas, United States of America
| | - Andrew K. Groves
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - John S. Oghalai
- Department of Otolaryngology–Head and Neck Surgery, Stanford University, Stanford, California, United States of America
- * E-mail:
| |
Collapse
|
39
|
Probst FJ, Corrigan RR, del Gaudio D, Salinger AP, Lorenzo I, Gao SS, Chiu I, Xia A, Oghalai JS, Justice MJ. A point mutation in the gene for asparagine-linked glycosylation 10B (Alg10b) causes nonsyndromic hearing impairment in mice (Mus musculus). PLoS One 2013; 8:e80408. [PMID: 24303013 PMCID: PMC3841196 DOI: 10.1371/journal.pone.0080408] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 10/02/2013] [Indexed: 01/10/2023] Open
Abstract
The study of mouse hearing impairment mutants has led to the identification of a number of human hearing impairment genes and has greatly furthered our understanding of the physiology of hearing. The novel mouse mutant neurological/sensory 5 (nse5) demonstrates a significantly reduced or absent startle response to sound and is therefore a potential murine model of human hearing impairment. Genetic analysis of 500 intercross progeny localized the mutant locus to a 524 kilobase (kb) interval on mouse chromosome 15. A missense mutation in a highly-conserved amino acid was found in the asparagine-linked glycosylation 10B gene (Alg10b), which is within the critical interval for the nse5 mutation. A 20.4 kb transgene containing a wildtype copy of the Alg10b gene rescued the mutant phenotype in nse5/nse5 homozygous animals, confirming that the mutation in Alg10b is responsible for the nse5/nse5 mutant phenotype. Homozygous nse5/nse5 mutants had abnormal auditory brainstem responses (ABRs), distortion product otoacoustic emissions (DPOAEs), and cochlear microphonics (CMs). Endocochlear potentials (EPs), on the other hand, were normal. ABRs and DPOAEs also confirmed the rescue of the mutant nse5/nse5 phenotype by the wildtype Alg10b transgene. These results suggested a defect in the outer hair cells of mutant animals, which was confirmed by histologic analysis. This is the first report of mutation in a gene involved in the asparagine (N)-linked glycosylation pathway causing nonsyndromic hearing impairment, and it suggests that the hearing apparatus, and the outer hair cells in particular, are exquisitely sensitive to perturbations of the N-linked glycosylation pathway.
Collapse
Affiliation(s)
- Frank J. Probst
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Rebecca R. Corrigan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Daniela del Gaudio
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Andrew P. Salinger
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Isabel Lorenzo
- Genetically Engineered Mouse Shared Resource, Baylor College of Medicine, Houston, Texas, United States of America
| | - Simon S. Gao
- Department of Bioengineering, Rice University, Houston, Texas, United States of America
| | - Ilene Chiu
- Department of Otolaryngology-Head and Neck Surgery, Baylor College of Medicine, Houston, Texas, United States of America
| | - Anping Xia
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, California, United States of America
| | - John S. Oghalai
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, California, United States of America
| | - Monica J. Justice
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- * E-mail:
| |
Collapse
|
40
|
Cho SI, Gao SS, Xia A, Wang R, Salles FT, Raphael PD, Abaya H, Wachtel J, Baek J, Jacobs D, Rasband MN, Oghalai JS. Mechanisms of hearing loss after blast injury to the ear. PLoS One 2013; 8:e67618. [PMID: 23840874 PMCID: PMC3698122 DOI: 10.1371/journal.pone.0067618] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 05/20/2013] [Indexed: 12/21/2022] Open
Abstract
Given the frequent use of improvised explosive devices (IEDs) around the world, the study of traumatic blast injuries is of increasing interest. The ear is the most common organ affected by blast injury because it is the body's most sensitive pressure transducer. We fabricated a blast chamber to re-create blast profiles similar to that of IEDs and used it to develop a reproducible mouse model to study blast-induced hearing loss. The tympanic membrane was perforated in all mice after blast exposure and found to heal spontaneously. Micro-computed tomography demonstrated no evidence for middle ear or otic capsule injuries; however, the healed tympanic membrane was thickened. Auditory brainstem response and distortion product otoacoustic emission threshold shifts were found to be correlated with blast intensity. As well, these threshold shifts were larger than those found in control mice that underwent surgical perforation of their tympanic membranes, indicating cochlear trauma. Histological studies one week and three months after the blast demonstrated no disruption or damage to the intra-cochlear membranes. However, there was loss of outer hair cells (OHCs) within the basal turn of the cochlea and decreased spiral ganglion neurons (SGNs) and afferent nerve synapses. Using our mouse model that recapitulates human IED exposure, our results identify that the mechanisms underlying blast-induced hearing loss does not include gross membranous rupture as is commonly believed. Instead, there is both OHC and SGN loss that produce auditory dysfunction.
Collapse
Affiliation(s)
- Sung-Il Cho
- Department of Otolaryngology–Head and Neck Surgery, Stanford University, Stanford, California, United States of America
- Department of Otolaryngology–Head and Neck Surgery, Chosun University, Gwangju, South Korea
| | - Simon S. Gao
- Department of Otolaryngology–Head and Neck Surgery, Stanford University, Stanford, California, United States of America
- Department of Bioengineering, Rice University, Houston, Texas, United States of America
| | - Anping Xia
- Department of Otolaryngology–Head and Neck Surgery, Stanford University, Stanford, California, United States of America
| | - Rosalie Wang
- Department of Otolaryngology–Head and Neck Surgery, Stanford University, Stanford, California, United States of America
| | - Felipe T. Salles
- Department of Otolaryngology–Head and Neck Surgery, Stanford University, Stanford, California, United States of America
| | - Patrick D. Raphael
- Department of Otolaryngology–Head and Neck Surgery, Stanford University, Stanford, California, United States of America
| | - Homer Abaya
- Department of Otolaryngology–Head and Neck Surgery, Stanford University, Stanford, California, United States of America
| | - Jacqueline Wachtel
- Department of Otolaryngology–Head and Neck Surgery, Stanford University, Stanford, California, United States of America
| | - Jongmin Baek
- Department of Computer Science, Stanford University, Stanford, California, United States of America
| | - David Jacobs
- Department of Computer Science, Stanford University, Stanford, California, United States of America
| | - Matthew N. Rasband
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, United States of America
| | - John S. Oghalai
- Department of Otolaryngology–Head and Neck Surgery, Stanford University, Stanford, California, United States of America
- * E-mail:
| |
Collapse
|
41
|
Jan TA, Chai R, Sayyid ZN, van Amerongen R, Xia A, Wang T, Sinkkonen ST, Zeng YA, Levin JR, Heller S, Nusse R, Cheng AGL. Tympanic border cells are Wnt-responsive and can act as progenitors for postnatal mouse cochlear cells. Development 2013; 140:1196-206. [PMID: 23444352 DOI: 10.1242/dev.087528] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Permanent hearing loss is caused by the irreversible damage of cochlear sensory hair cells and nonsensory supporting cells. In the postnatal cochlea, the sensory epithelium is terminally differentiated, whereas tympanic border cells (TBCs) beneath the sensory epithelium are proliferative. The functions of TBCs are poorly characterized. Using an Axin2(lacZ) Wnt reporter mouse, we found transient but robust Wnt signaling and proliferation in TBCs during the first 3 postnatal weeks, when the number of TBCs decreases. In vivo lineage tracing shows that a subset of hair cells and supporting cells is derived postnatally from Axin2-expressing TBCs. In cochlear explants, Wnt agonists stimulated the proliferation of TBCs, whereas Wnt inhibitors suppressed it. In addition, purified Axin2(lacZ) cells were clonogenic and self-renewing in culture in a Wnt-dependent manner, and were able to differentiate into hair cell-like and supporting cell-like cells. Taken together, our data indicate that Axin2-positive TBCs are Wnt responsive and can act as precursors to sensory epithelial cells in the postnatal cochlea.
Collapse
Affiliation(s)
- Taha Adnan Jan
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Gao SS, Raphael PD, Wang R, Park J, Xia A, Applegate BE, Oghalai JS. In vivo vibrometry inside the apex of the mouse cochlea using spectral domain optical coherence tomography. Biomed Opt Express 2013. [PMID: 23411442 DOI: 10.1364/boe.4.000230] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Sound transduction within the auditory portion of the inner ear, the cochlea, is a complex nonlinear process. The study of cochlear mechanics in large rodents has provided important insights into cochlear function. However, technological and experimental limitations have restricted studies in mice due to their smaller cochlea. These challenges are important to overcome because of the wide variety of transgenic mouse strains with hearing loss mutations that are available for study. To accomplish this goal, we used spectral domain optical coherence tomography to visualize and measure sound-induced vibrations of intracochlear tissues. We present, to our knowledge, the first vibration measurements from the apex of an unopened mouse cochlea.
Collapse
Affiliation(s)
- Simon S Gao
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA 94305, USA ; Department of Bioengineering, Rice University, 6100 Main Street, Houston, TX 77005, USA
| | | | | | | | | | | | | |
Collapse
|
43
|
Gao SS, Raphael PD, Wang R, Park J, Xia A, Applegate BE, Oghalai JS. In vivo vibrometry inside the apex of the mouse cochlea using spectral domain optical coherence tomography. Biomed Opt Express 2013; 4:230-40. [PMID: 23411442 PMCID: PMC3567710 DOI: 10.1364/boe.4.00230] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Revised: 01/11/2013] [Accepted: 01/14/2013] [Indexed: 05/03/2023]
Abstract
Sound transduction within the auditory portion of the inner ear, the cochlea, is a complex nonlinear process. The study of cochlear mechanics in large rodents has provided important insights into cochlear function. However, technological and experimental limitations have restricted studies in mice due to their smaller cochlea. These challenges are important to overcome because of the wide variety of transgenic mouse strains with hearing loss mutations that are available for study. To accomplish this goal, we used spectral domain optical coherence tomography to visualize and measure sound-induced vibrations of intracochlear tissues. We present, to our knowledge, the first vibration measurements from the apex of an unopened mouse cochlea.
Collapse
Affiliation(s)
- Simon S. Gao
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA 94305, USA
- Department of Bioengineering, Rice University, 6100 Main Street, Houston, TX 77005, USA
| | - Patrick D. Raphael
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA 94305, USA
| | - Rosalie Wang
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA 94305, USA
| | - Jesung Park
- Department of Biomedical Engineering, Texas A&M University, 337 Zachry Engineering Center, 3120 TAMU, College Station, TX 77843, USA
| | - Anping Xia
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA 94305, USA
| | - Brian E. Applegate
- Department of Biomedical Engineering, Texas A&M University, 337 Zachry Engineering Center, 3120 TAMU, College Station, TX 77843, USA
| | - John S. Oghalai
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA 94305, USA
- Department of Bioengineering, Rice University, 6100 Main Street, Houston, TX 77005, USA
| |
Collapse
|
44
|
|
45
|
Gueta R, Levitt J, Xia A, Katz O, Oghalai JS, Rousso I. Structural and mechanical analysis of tectorial membrane Tecta mutants. Biophys J 2011; 100:2530-8. [PMID: 21575588 DOI: 10.1016/j.bpj.2011.04.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2010] [Revised: 03/15/2011] [Accepted: 04/04/2011] [Indexed: 11/18/2022] Open
Abstract
The tectorial membrane (TM) is an extracellular matrix of the cochlea whose prominent role in hearing has been demonstrated through mutation studies. The C1509G mutation of the Tecta gene, which encodes for the α-tectorin protein, leads to hearing loss. The heterozygote TM only attaches to the first row of outer hair cells (OHCs), and the homozygote TM does not attach to any OHCs. Here we measured the morphology and mechanical properties of wild-type, heterozygous, and homozygous Tecta TMs. Morphological analyses conducted with second- and third-harmonic imaging, scanning electron microscopy, and immunolabeling revealed marked changes in the collagen architecture and stereocilin-labeling patterns of the mutant TMs. The mechanical properties of the mutant TM were measured by force spectroscopy. Whereas the axial Young's modulus of the low-frequency (apical) region of Tecta mutant TM samples was similar to that of wild-type TMs, it significantly decreased in the basal region to a value approaching that found at the apex. Modeling simulations suggest that a reduced TM Young's modulus is likely to reduce OHC stereociliary deflection. These findings argue that the heterozygote C1509G mutation results in a lack of attachment of the TM to the OHCs, which in turn reduces both the overall number of OHCs that are involved in mechanotransduction and the degree of mechanotransduction exhibited by the OHCs that remain attached to the TM.
Collapse
Affiliation(s)
- Rachel Gueta
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | | | | | | | | | | |
Collapse
|
46
|
Gao SS, Xia A, Yuan T, Raphael PD, Shelton RL, Applegate BE, Oghalai JS. Quantitative imaging of cochlear soft tissues in wild-type and hearing-impaired transgenic mice by spectral domain optical coherence tomography. Opt Express 2011; 19:15415-28. [PMID: 21934905 PMCID: PMC3482885 DOI: 10.1364/oe.19.015415] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Human hearing loss often occurs as a result of damage or malformations to the functional soft tissues within the cochlea, but these changes are not appreciable with current medical imaging modalities. We sought to determine whether optical coherence tomography (OCT) could assess the soft tissue structures relevant to hearing using mouse models. We imaged excised cochleae with an altered tectorial membrane and during normal development. The soft tissue structures and expected anatomical variations were visible using OCT, and quantitative measurements confirmed the ability to detect critical changes relevant to hearing.
Collapse
Affiliation(s)
- Simon S. Gao
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA 94305,
USA
- Department of Bioengineering, Rice University, 6100 Main Street, Houston, TX 77005,
USA
| | - Anping Xia
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA 94305,
USA
| | - Tao Yuan
- Department of Otolaryngology-Head and Neck Surgery, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030,
USA
| | - Patrick D. Raphael
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA 94305,
USA
| | - Ryan L. Shelton
- Department of Biomedical Engineering, Texas A&M University, 337 Zachry Engineering Center, 3120 TAMU, College Station, TX 77843
USA
| | - Brian E. Applegate
- Department of Biomedical Engineering, Texas A&M University, 337 Zachry Engineering Center, 3120 TAMU, College Station, TX 77843
USA
| | - John S. Oghalai
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, CA 94305,
USA
- Department of Bioengineering, Rice University, 6100 Main Street, Houston, TX 77005,
USA
| |
Collapse
|
47
|
Chai R, Xia A, Wang T, Jan TA, Hayashi T, Bermingham-McDonogh O, Cheng AGL. Dynamic expression of Lgr5, a Wnt target gene, in the developing and mature mouse cochlea. J Assoc Res Otolaryngol 2011; 12:455-69. [PMID: 21472479 DOI: 10.1007/s10162-011-0267-2] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Accepted: 03/17/2011] [Indexed: 12/11/2022] Open
Abstract
The Wnt signaling pathway is a recurring theme in tissue development and homeostasis. Its specific roles during inner ear development are just emerging, but few studies have characterized Wnt target genes. Lgr5, a member of the G protein-coupled receptor family, is a Wnt target in the gastrointestinal and integumentary systems. Although its function is unknown, its deficiency leads to perinatal lethality due to gastrointestinal distension. In this study, we used a knock-in reporter mouse to examine the spatiotemporal expression of Lgr5 in the cochlear duct during embryonic and postnatal periods. In the embryonic day 15.5 (E15.5) cochlear duct, Lgr5-EGFP is expressed in the floor epithelium and overlapped with the prosensory markers Sox2, Jagged1, and p27(Kip1). Nascent hair cells and supporting cells in the apical turn of the E18.5 cochlear duct express Lgr5-EGFP, which becomes downregulated in hair cells and subsets of supporting cells in more mature stages. In situ hybridization experiments validated the reporter expression, which gradually decreases until the second postnatal week. Only the third row of Deiters' cells expresses Lgr5-EGFP in the mature organ of Corti. Normal cochlear development was observed in Lgr5(EGFP/EGFP) and Lgr5(EGFP/+) mice, which exhibited normal auditory thresholds. The expression pattern of Lgr5 contrasts with another Wnt target gene, Axin2, a feedback inhibitor of the Wnt pathway. Robust Axin2 expression was found in cells surrounding the embryonic cochlear duct and becomes restricted to tympanic border cells below the basilar membrane in the postnatal cochlea. Both Lgr5 and Axin2 act as Wnt targets in the cochlea because purified Wnt3a promoted and Wnt antagonist suppressed their expression. Their differential expression among cell populations highlights the dynamic but complex distribution of Wnt-activated cells in and around the embryonic and postnatal cochlea.
Collapse
Affiliation(s)
- Renjie Chai
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, CA 94305, USA
| | | | | | | | | | | | | |
Collapse
|
48
|
Xia A, Gao SS, Yuan T, Osborn A, Bress A, Pfister M, Maricich SM, Pereira FA, Oghalai JS. Deficient forward transduction and enhanced reverse transduction in the alpha tectorin C1509G human hearing loss mutation. Dis Model Mech 2010; 3:209-23. [PMID: 20142329 DOI: 10.1242/dmm.004135] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Most forms of hearing loss are associated with loss of cochlear outer hair cells (OHCs). OHCs require the tectorial membrane (TM) for stereociliary bundle stimulation (forward transduction) and active feedback (reverse transduction). Alpha tectorin is a protein constituent of the TM and the C1509G mutation in alpha tectorin in humans results in autosomal dominant hearing loss. We engineered and validated this mutation in mice and found that the TM was shortened in heterozygous Tecta(C1509G/+) mice, reaching only the first row of OHCs. Thus, deficient forward transduction renders OHCs within the second and third rows non-functional, producing partial hearing loss. Surprisingly, both Tecta(C1509G/+) and Tecta(C1509G/C1509G) mice were found to have increased reverse transduction as assessed by sound- and electrically-evoked otoacoustic emissions. We show that an increase in prestin, a protein necessary for electromotility, in all three rows of OHCs underlies this phenomenon. This mouse model demonstrates a human hearing loss mutation in which OHC function is altered through a non-cell-autonomous variation in prestin.
Collapse
Affiliation(s)
- Anping Xia
- The Bobby R. Alford Department of Otolaryngology - Head and Neck Surgery, Baylor College of Medicine, Houston, TX 77030, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Osborn A, Xia A, Gao S, Maricich S, Pereira F, Oghalai J. Altered tectorial membrane development and outer hair cell physiology in an α-tectorintransgenic mouse. Laryngoscope 2009. [DOI: 10.1002/lary.21556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
50
|
Xia A, Wooltorton JRA, Palmer DJ, Ng P, Pereira FA, Eatock RA, Oghalai JS. Functional prestin transduction of immature outer hair cells from normal and prestin-null mice. J Assoc Res Otolaryngol 2008; 9:307-20. [PMID: 18506528 DOI: 10.1007/s10162-008-0121-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2007] [Accepted: 04/04/2008] [Indexed: 10/22/2022] Open
Abstract
Prestin is a membrane protein in the outer hair cell (OHC) that has been shown to be essential for electromotility. OHCs from prestin-null mice do not express prestin, do not have a nonlinear capacitance (the electrical signature of electromotility), and are smaller in size than wild-type OHCs. We sought to determine whether prestin-null OHCs can be transduced to incorporate functional prestin protein in a normal fashion. A recombinant helper-dependent adenovirus expressing prestin and green fluorescent protein (HDAd-prestin-GFP) was created and tested in human embryonic kidney cells (HEK cells). Transduced HEK cells demonstrated membrane expression of prestin and nonlinear capacitance. HDAd-prestin-GFP was then applied to cochlear sensory epithelium explants harvested from wild-type and prestin-null mice at postnatal days 2-3, the age at which native prestin is just beginning to become functional in wild-type mice. At postnatal days 4-5, we investigated transduced OHCs for (1) their prestin expression pattern as revealed by immunofluorescence; (2) their cell surface area as measured by linear capacitance; and (3) their prestin function as indicated by nonlinear capacitance. HDAd-prestin-GFP efficiently transduced OHCs of both genotypes and prestin protein localized to the plasma membrane. Whole-cell voltage clamp studies revealed a nonlinear capacitance in transduced wild-type and prestin-null OHCs, but not in non-transduced cells of either genotype. Prestin transduction did not increase the linear capacitance (cell surface area) for either genotype. In peak nonlinear capacitance, voltage at peak nonlinear capacitance, charge density of the nonlinear capacitance, and shape of the voltage-capacitance curves, the transduced cells of the two genotypes resembled each other and previously reported data from adult wild-type mouse OHCs. Thus, prestin introduced into prestin-deficient OHCs segregates normally to the cell membrane and generates a normal nonlinear capacitance, indicative of normal prestin function.
Collapse
Affiliation(s)
- Anping Xia
- Bobby R. Alford Department of Otolaryngology, Head and Neck Surgery, Baylor College of Medicine, One Baylor Plaza, NA102, Houston, TX 77030, USA
| | | | | | | | | | | | | |
Collapse
|