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Hearing Disorders: HELP
Articles by Prem Chapagain
Based on 4 articles published since 2010
(Why 4 articles?)
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Between 2010 and 2020, Prem Chapagain wrote the following 4 articles about Hearing Disorders.
 
+ Citations + Abstracts
1 Review Genetic basis of hearing loss in Spanish, Hispanic and Latino populations. 2018

Mittal, Rahul / Patel, Amit P / Nguyen, Desiree / Pan, Debbie R / Jhaveri, Vasanti M / Rudman, Jason R / Dharmaraja, Arjuna / Yan, Denise / Feng, Yong / Chapagain, Prem / Lee, David J / Blanton, Susan H / Liu, Xue Zhong. ·Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA. · Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, China. · Department of Physics and Biomolecular Sciences Institute, Florida International University, Miami, FL, USA. · Department of Public Health Sciences, University of Miami Miller School of Medicine, Miami, FL, USA. · Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA; Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genetics, University of Miami Miller School of Medicine, Miami, FL 33136, USA. · Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, China; Tsinghua University School of Medicine, Beijing 10084, China; Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genetics, University of Miami Miller School of Medicine, Miami, FL 33136, USA. Electronic address: xliu@med.miami.edu. ·Gene · Pubmed #29331482.

ABSTRACT: Hearing loss (HL) is the most common neurosensory disorder affecting humans. The screening, prevention and treatment of HL require a better understanding of the underlying molecular mechanisms. Genetic predisposition is one of the most common factors that leads to HL. Most HL studies include few Spanish, Hispanic and Latino participants, leaving a critical gap in our understanding about the prevalence, impact, unmet health care needs, and genetic factors associated with hearing impairment among Spanish, Hispanic and Latino populations. The few studies which have been performed show that the gene variants commonly associated with HL in non-Spanish and non-Hispanic populations are infrequently responsible for hearing impairment in Spanish as well as Hispanic and Latino populations (hereafter referred to as Hispanic). To design effective screening tools to detect HL in Spanish and Hispanic populations, studies must be conducted to determine the gene variants that are most commonly associated with hearing impairment in this racial/ethnic group. In this review article, we summarize gene variants and loci associated with HL in Spanish and Hispanic populations. Identifying new genetic variants associated with HL in Spanish and Hispanic populations will pave the way to develop effective screening tools and therapeutic strategies for HL.

2 Review Molecular Structure and Regulation of P2X Receptors With a Special Emphasis on the Role of P2X2 in the Auditory System. 2016

Mittal, Rahul / Chan, Brandon / Grati, M'hamed / Mittal, Jeenu / Patel, Kunal / Debs, Luca H / Patel, Amit P / Yan, Denise / Chapagain, Prem / Liu, Xue Zhong. ·Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida. · Department of Physics, Florida International University, Miami, Florida. · Biomolecular Science Institute, Florida International University, Miami, Florida. · Department of Human Genetics, University of Miami Miller School of Medicine, Miami, Florida. · Department of Biochemistry, University of Miami Miller School of Medicine, Miami, Florida. ·J Cell Physiol · Pubmed #26627116.

ABSTRACT: The P2X purinergic receptors are cation-selective channels gated by extracellular adenosine 5'-triphosphate (ATP). These purinergic receptors are found in virtually all mammalian cell types and facilitate a number of important physiological processes. Within the past few years, the characterization of crystal structures of the zebrafish P2X4 receptor in its closed and open states has provided critical insights into the mechanisms of ligand binding and channel activation. Understanding of this gating mechanism has facilitated to design and interpret new modeling and structure-function experiments to better elucidate how different agonists and antagonists can affect the receptor with differing levels of potency. This review summarizes the current knowledge on the structure, activation, allosteric modulators, function, and location of the different P2X receptors. Moreover, an emphasis on the P2X2 receptors has been placed in respect to its role in the auditory system. In particular, the discovery of three missense mutations in P2X2 receptors could become important areas of study in the field of gene therapy to treat progressive and noise-induced hearing loss. J. Cell. Physiol. 231: 1656-1670, 2016. © 2015 Wiley Periodicals, Inc.

3 Article A dominant variant in the PDE1C gene is associated with nonsyndromic hearing loss. 2018

Wang, Li / Feng, Yong / Yan, Denise / Qin, Litao / Grati, M'hamed / Mittal, Rahul / Li, Tao / Sundhari, Abhiraami Kannan / Liu, Yalan / Chapagain, Prem / Blanton, Susan H / Liao, Shixiu / Liu, Xuezhong. ·Institute of Medical Genetics, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, China. · Department of Otolaryngology (D-48), Miller School of Medicine, University of Miami, 1666 NW 12th Avenue, Miami, FL, 33136, USA. · Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, China. · Laboratory of Cell Structure and Dynamics, NIDCD, NIH, Bethesda, MD, 20892, USA. · Department of Physics, Florida International University, Miami, FL, USA. · Biomolecular Sciences Institute, Florida International University, Miami, FL, USA. · Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL, 33136, USA. · Department of Otolaryngology (D-48), Miller School of Medicine, University of Miami, 1666 NW 12th Avenue, Miami, FL, 33136, USA. xliu@med.miami.edu. · Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, China. xliu@med.miami.edu. · Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL, 33136, USA. xliu@med.miami.edu. ·Hum Genet · Pubmed #29860631.

ABSTRACT: Identification of genes with variants causing non-syndromic hearing loss (NSHL) is challenging due to genetic heterogeneity. The difficulty is compounded by technical limitations that in the past prevented comprehensive gene identification. Recent advances in technology, using targeted capture and next-generation sequencing (NGS), is changing the face of gene identification and making it possible to rapidly and cost-effectively sequence the whole human exome. Here, we characterize a five-generation Chinese family with progressive, postlingual autosomal dominant nonsyndromic hearing loss (ADNSHL). By combining population-specific mutation arrays, targeted deafness genes panel, whole exome sequencing (WES), we identified PDE1C (Phosphodiesterase 1C) c.958G>T (p.A320S) as the disease-associated variant. Structural modeling insights into p.A320S strongly suggest that the sequence alteration will likely affect the substrate-binding pocket of PDE1C. By whole-mount immunofluorescence on postnatal day 3 mouse cochlea, we show its expression in outer (OHC) and inner (IHC) hair cells cytosol co-localizing with Lamp-1 in lysosomes. Furthermore, we provide evidence that the variant alters the PDE1C hydrolytic activity for both cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). Collectively, our findings indicate that the c.958G>T variant in PDE1C may disrupt the cross talk between cGMP-signaling and cAMP pathways in Ca

4 Article ELMOD3, a novel causative gene, associated with human autosomal dominant nonsyndromic and progressive hearing loss. 2018

Li, Wu / Sun, Jie / Ling, Jie / Li, Jiada / He, Chufeng / Liu, Yalan / Chen, Hongsheng / Men, Meichao / Niu, Zhijie / Deng, Yuyuan / Li, Meng / Li, Taoxi / Wen, Jie / Sang, Shushan / Li, Haibo / Wan, Zhengqing / Richard, Elodie M / Chapagain, Prem / Yan, Denise / Liu, Xue Zhong / Mei, Lingyun / Feng, Yong. ·Department of Otolaryngology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan, China. · Province Key Laboratory of Otolaryngology Critical Diseases, Changsha, Hunan, China. · Department of Otolaryngology, The Eight Affiliated Hospital, Sun Yat-sen University, 3025 Shennan Middle Road, Shenzhen, Guangdong, China. · Institute of Precision Medicine, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan, China. · Center for Medical Genetics, Central South University, 110 Xiangya Road, Changsha, Hunan, China. · School of Life Sciences, Central South University of China, 110 Xiangya Road, Changsha, Hunan, China. · Health Management Center, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan, China. · Department of Ophthalmology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan, China. · Department of Otorhinolaryngology Head and Neck Surgery, School of Medicine, University of Maryland, Baltimore, MD, USA. · Department of Physics, Florida International University, Miami, Florida, USA. · Biomolecular Sciences Institute, Florida International University, Miami, FL, USA. · Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, USA. · Dr. John T. Macdonald Foundation, Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL, 33136, USA. · Department of Otolaryngology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan, China. entmly@163.com. · Province Key Laboratory of Otolaryngology Critical Diseases, Changsha, Hunan, China. entmly@163.com. · Department of Otolaryngology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan, China. fengyong_hn@hotmail.com. · Province Key Laboratory of Otolaryngology Critical Diseases, Changsha, Hunan, China. fengyong_hn@hotmail.com. ·Hum Genet · Pubmed #29713870.

ABSTRACT: Autosomal dominant nonsyndromic hearing loss (ADNSHL) is a highly genetically heterogeneous disorder. Up to date only approximately 37 ADNSHL-causing genes have been identified. The goal of this study was to determine the causative gene in a five-generation Chinese family with ADNSHL. A Chinese family was ascertained. Simultaneously, two affected individuals and one normal hearing control from the family were analyzed by whole exome capture sequencing. To assess the functional effect of the identified variant, in-vitro studies were performed. novel missense variant, c.512A>G (p.His171Arg) in exon 8 of the ELMO domain-containing 3 (ELMOD3) gene, was identified as a causative variant in this family affected by late-onset and progressive ADNSHL. The variant was validated by Sanger sequencing and found to co-segregate with the phenotype within the pedigree and was absent in 500 ethnically matched unrelated normal hearing control subjects. To our knowledge, this is the first report of a family with ADNSHL caused by ELMOD3 mutation. Western blots and immunofluorescence staining demonstrated that p.His171Arg resulted in abnormal expression levels of ELMOD3 and abnormal subcellular localization. Furthermore, the analysis of the stability of the wild-type (WT) and mutant ELMOD3 protein shows that the decay of p.His171Arg is faster than that of the WT, suggesting a shorter halflife of the c.512A > G variant. A novel variant in the ELMOD3 gene, encoding a member of the engulfment and cell motility (ELMO) family of GTPase-activating proteins, was identified for the first time as responsible for ADNSHL.