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Tu H, Zhang A, Fu X, Xu S, Bai X, Wang H, Gao J. SMPX Deficiency Causes Stereocilia Degeneration and Progressive Hearing Loss in CBA/CaJ Mice. Front Cell Dev Biol 2021; 9:750023. [PMID: 34722533 PMCID: PMC8551870 DOI: 10.3389/fcell.2021.750023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 09/17/2021] [Indexed: 11/13/2022] Open
Abstract
The small muscle protein, x-linked (SMPX) encodes a small protein containing 88 amino acids. Malfunction of this protein can cause a sex-linked non-syndromic hearing loss, named X-linked deafness 4 (DFNX4). Herein, we reported a point mutation and a frameshift mutation in two Chinese families who developed gradual hearing loss with age. To explore the impaired sites in the hearing system and the mechanism of DFNX4, we established and validated an Smpx null mouse model using CRISPR-Cas9. By analyzing auditory brainstem response (ABR), male Smpx null mice showed a progressive hearing loss starting from high frequency at the 3rd month. Hearing loss in female mice was milder and occurred later compared to male mice, which was very similar to human beings. Through morphological analyses of mice cochleas, we found the hair cell bundles progressively degenerated from the shortest row. Cellular edema occurred at the end phase of stereocilia degeneration, followed by cell death. By transfecting exogenous fluorescent Smpx into living hair cells, Smpx was observed to be expressed in stereocilia. Through noise exposure, it was shown that Smpx might participate in maintaining hair cell bundles. This Smpx knock-out mouse might be used as a suitable model to explore the pathology of DFNX4.
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Affiliation(s)
- Hailong Tu
- School of Life Sciences, Shandong Provincial ENT Hospital, Shandong University, Jinan, China
| | - Aizhen Zhang
- School of Life Sciences, Shandong Provincial ENT Hospital, Shandong University, Jinan, China
| | - Xiaolong Fu
- School of Life Sciences, Shandong Provincial ENT Hospital, Shandong University, Jinan, China
| | - Shiqi Xu
- University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Haining, China
| | - Xiaohui Bai
- Otolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Jinan, China
| | - Haibo Wang
- School of Life Sciences, Shandong Provincial ENT Hospital, Shandong University, Jinan, China.,Otolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Jinan, China
| | - Jiangang Gao
- School of Life Sciences, Shandong Provincial ENT Hospital, Shandong University, Jinan, China
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Ghilardi A, Diana A, Bacchetta R, Santo N, Ascagni M, Prosperi L, Del Giacco L. Inner Ear and Muscle Developmental Defects in Smpx-Deficient Zebrafish Embryos. Int J Mol Sci 2021; 22:ijms22126497. [PMID: 34204426 PMCID: PMC8235540 DOI: 10.3390/ijms22126497] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/09/2021] [Accepted: 06/12/2021] [Indexed: 12/20/2022] Open
Abstract
The last decade has witnessed the identification of several families affected by hereditary non-syndromic hearing loss (NSHL) caused by mutations in the SMPX gene and the loss of function has been suggested as the underlying mechanism. In the attempt to confirm this hypothesis we generated an Smpx-deficient zebrafish model, pointing out its crucial role in proper inner ear development. Indeed, a marked decrease in the number of kinocilia together with structural alterations of the stereocilia and the kinocilium itself in the hair cells of the inner ear were observed. We also report the impairment of the mechanotransduction by the hair cells, making SMPX a potential key player in the construction of the machinery necessary for sound detection. This wealth of evidence provides the first possible explanation for hearing loss in SMPX-mutated patients. Additionally, we observed a clear muscular phenotype consisting of the defective organization and functioning of muscle fibers, strongly suggesting a potential role for the protein in the development of muscle fibers. This piece of evidence highlights the need for more in-depth analyses in search for possible correlations between SMPX mutations and muscular disorders in humans, thus potentially turning this non-syndromic hearing loss-associated gene into the genetic cause of dysfunctions characterized by more than one symptom, making SMPX a novel syndromic gene.
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Affiliation(s)
- Anna Ghilardi
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy; (A.G.); (A.D.); (L.P.)
| | - Alberto Diana
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy; (A.G.); (A.D.); (L.P.)
| | - Renato Bacchetta
- Department of Environmental Science and Policy, Università degli Studi di Milano, 20133 Milan, Italy;
| | - Nadia Santo
- Unitech NOLIMITS, Università degli Studi di Milano, 20133 Milan, Italy; (N.S.); (M.A.)
| | - Miriam Ascagni
- Unitech NOLIMITS, Università degli Studi di Milano, 20133 Milan, Italy; (N.S.); (M.A.)
| | - Laura Prosperi
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy; (A.G.); (A.D.); (L.P.)
| | - Luca Del Giacco
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy; (A.G.); (A.D.); (L.P.)
- Correspondence:
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3
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Guo Y, Hao Y, Zhang D, Xu H, Yu D, Lv J, Fu Z, Han S, Guo F, Bai J, Guan G. A novel missense mutation in SMPX causes a rare form of X-linked postlingual sensorineural hearing loss in a Chinese family. Transl Pediatr 2021; 10:378-387. [PMID: 33708524 PMCID: PMC7944167 DOI: 10.21037/tp-20-435] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND X-linked deafness-4 (DFNX4) caused by the functional loss of the SMPX gene is one form of nonsyndromic hearing loss with postlingual onset. This study aimed to investigate the cause of X-linked inherited sensorineural nonsyndromic hearing loss in a four-generation Chinese family and to explain the reason for extremely different hearing phenotypes between the proband and other family members. METHODS Whole-exome sequencing (WES) and co-segregation analysis were used to identify the pathogenic variants. Furthermore, methylation differences among the androgen receptor genes were utilized to investigate whether the severe phenotype of the proband is related to X-chromosome inactivation (Xi). RESULTS We described in detail the clinical characteristics of the family and identified a novel missense mutation (c.262C>G: p.Gln88Glu) in SMPX by WES. This variant was co-segregated with the postlingual hearing loss phenotype and was absent in 300 normal controls. Also, we found that the proband, a 4-year-old female, carries two new compound heterozygous mutations (c.9259G>A: p.Val3087Ile and c.8576G>A: p.Arg2859His) in the USH2A gene, but to date without any other symptoms except profound sensorineural hearing loss. Additionally, analysis of X-chromosome inactivation indicated moderate skewing in the proband, which is probably related to the heterogeneity of clinical characteristics. CONCLUSIONS This is the first study to report a missense mutation of SMPX in a Chinese family. Our findings have enriched the mutation and phenotypic spectrum of the SMPX gene.
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Affiliation(s)
- Yingyuan Guo
- Department of Otolaryngology, The Second Hospital of Jilin University, Changchun, China
| | - Yanru Hao
- Department of Otolaryngology, The Second Hospital of Jilin University, Changchun, China
| | - Dejun Zhang
- Department of Otolaryngology, The Second Hospital of Jilin University, Changchun, China
| | - Hongen Xu
- Precision Medicine Center, Academy of Medical Science, Zhengzhou University, Zhengzhou, China
| | - Duojiao Yu
- Department of Otolaryngology, The Second Hospital of Jilin University, Changchun, China
| | - Jingmao Lv
- Department of Spinal Surgery, Jilin Province People's Hospital, Changchun, China
| | - Zeming Fu
- Department of Otolaryngology, The Second Hospital of Jilin University, Changchun, China
| | - Shuang Han
- Department of Otolaryngology, The Second Hospital of Jilin University, Changchun, China
| | - Fang Guo
- Department of Otolaryngology, The Second Hospital of Jilin University, Changchun, China
| | - Jie Bai
- Department of Otolaryngology, The Second Hospital of Jilin University, Changchun, China
| | - Guofang Guan
- Department of Otolaryngology, The Second Hospital of Jilin University, Changchun, China
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Portrait of Tissue-Specific Coexpression Networks of Noncoding RNAs (miRNA and lncRNA) and mRNAs in Normal Tissues. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2019; 2019:9029351. [PMID: 31565069 PMCID: PMC6745163 DOI: 10.1155/2019/9029351] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 08/01/2019] [Accepted: 08/10/2019] [Indexed: 02/01/2023]
Abstract
Genes that encode proteins playing a role in more than one biological process are frequently dependent on their tissue context, and human diseases result from the altered interplay of tissue- and cell-specific processes. In this work, we performed a computational approach that identifies tissue-specific co-expression networks by integrating miRNAs, long-non-coding RNAs, and mRNAs in more than eight thousands of human samples from thirty normal tissue types. Our analysis (1) shows that long-non coding RNAs and miRNAs have a high specificity, (2) confirms several known tissue-specific RNAs, and (3) identifies new tissue-specific co-expressed RNAs that are currently still not described in the literature. Some of these RNAs interact with known tissue-specific RNAs or are crucial in key cancer functions, suggesting that they are implicated in tissue specification or cell differentiation.
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Lv Y, Gu J, Qiu H, Li H, Zhang Z, Yin S, Mao Y, Kong L, Liang B, Jiang H, Liu C. Whole-exome sequencing identifies a donor splice-site variant in SMPX that causes rare X-linked congenital deafness. Mol Genet Genomic Med 2019; 7:e967. [PMID: 31478598 PMCID: PMC6825843 DOI: 10.1002/mgg3.967] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 07/31/2019] [Accepted: 08/05/2019] [Indexed: 12/17/2022] Open
Abstract
Background X‐linked deafness‐4 (DFNX4) caused by functional loss of SMPX is a nonsyndromic form of progressive hearing loss with post‐lingual onset. Herein, we describe a male neonate from an ethnic Han Chinese family who presented with congenital deafness. Methods The proband and the family members were subjected to comprehensively hearing screen. Genetic testing was carried out using whole‐exome sequencing (WES). The result was verified by Sanger sequencing. Functional characterization of the identified variant was completed by reverse transcription PCR (RT‐PCR), Sanger sequencing, and fluorogenic quantitative PCR (qPCR). Results The proband was diagnosed with progressive sensorineural hearing loss. The proband's mother showed normal hearing at present. The proband's maternal grandmother exhibited mild HL since the age of 50. Using whole‐exome sequencing (WES), we identified a donor splice‐site variant (NM_014332.2: c.132 + 1G>A) in the SMPX gene in the proband. The mother and maternal grandmother were both carriers, which suggested a X‐linked inheritance of the condition in the family. RT‐PCR and Sanger sequencing revealed that four alternative splice pairs within intron 3 have led to four aberrant RNAs transcripts, including two non‐canonical splice‐pairs (GC‐AG and CT‐AG). The variant generated a novel frameshift variant, creating a premature termination codon (PTC) upstream of a newly formed splice site (p.Met45Glyfs*16). SMPX mRNA expression assay showed that the PTC has caused degradation of mRNA via nonsense‐mediated mRNA decay (NMD). Conclusion This is the first study to report a SMPX (DFNX4) splicing variant in a Chinese family. These findings, especially congenital deafness, contributed to existing knowledge regarding the genotypic and phenotypic spectrum of SMPX‐associated hearing loss.
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Affiliation(s)
- Yuan Lv
- Key Laboratory of Maternal-Fetal Medicine of Liaoning Province, Key Laboratory of Obstetrics and Gynecology of Higher Education of Liaoning Province, Liaoning Centre for Prenatal Diagnosis, Research Center of China Medical University Birth Cohort, Department of Gynecology & Obstetrics, Shengjing Hospital Affiliated to China Medical University, Shenyang, Liaoning, China
| | - Jia Gu
- Department of Otolaryngology, The First Hospital Affiliated to China Medical University, Shenyang, Liaoning, China
| | - Hao Qiu
- Basecare Medical Device Co., Ltd., Suzhou, Jiangsu, China
| | - Huan Li
- Key Laboratory of Maternal-Fetal Medicine of Liaoning Province, Key Laboratory of Obstetrics and Gynecology of Higher Education of Liaoning Province, Liaoning Centre for Prenatal Diagnosis, Research Center of China Medical University Birth Cohort, Department of Gynecology & Obstetrics, Shengjing Hospital Affiliated to China Medical University, Shenyang, Liaoning, China
| | - Zhitao Zhang
- Key Laboratory of Maternal-Fetal Medicine of Liaoning Province, Key Laboratory of Obstetrics and Gynecology of Higher Education of Liaoning Province, Liaoning Centre for Prenatal Diagnosis, Research Center of China Medical University Birth Cohort, Department of Gynecology & Obstetrics, Shengjing Hospital Affiliated to China Medical University, Shenyang, Liaoning, China
| | - Shaowei Yin
- Key Laboratory of Maternal-Fetal Medicine of Liaoning Province, Key Laboratory of Obstetrics and Gynecology of Higher Education of Liaoning Province, Liaoning Centre for Prenatal Diagnosis, Research Center of China Medical University Birth Cohort, Department of Gynecology & Obstetrics, Shengjing Hospital Affiliated to China Medical University, Shenyang, Liaoning, China
| | - Yan Mao
- Basecare Medical Device Co., Ltd., Suzhou, Jiangsu, China
| | - Lingyin Kong
- Basecare Medical Device Co., Ltd., Suzhou, Jiangsu, China
| | - Bo Liang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Hongkun Jiang
- Department of Pediatrics, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning, China
| | - Caixia Liu
- Key Laboratory of Maternal-Fetal Medicine of Liaoning Province, Key Laboratory of Obstetrics and Gynecology of Higher Education of Liaoning Province, Liaoning Centre for Prenatal Diagnosis, Research Center of China Medical University Birth Cohort, Department of Gynecology & Obstetrics, Shengjing Hospital Affiliated to China Medical University, Shenyang, Liaoning, China
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6
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Wu Y, Zhang J, Wang M, Yang L, Wang Y, Hu T, Liu A, Cheng Q, Fu Z, Zhang P, Cao L. Proteomics analysis indicated the protein expression pattern related to the development of fetal conotruncal defects. J Cell Physiol 2019; 234:13544-13556. [PMID: 30635921 DOI: 10.1002/jcp.28033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Accepted: 11/30/2018] [Indexed: 11/08/2022]
Abstract
Abnormal development of embryonic conus arteriosus could lead to conotruncal defects in fetal heart, and increase the incidence of fetal congenital heart disease. Tetralogy of Fallot (TOF) is one of the most common forms of congenital heart disease. It may be helpful for us to solve this clinical problem through exploring the molecular mechanisms of development in embryonic congenital heart disease. Proteomics has attracted much attention in understanding the development of human diseases during the past decades. However, there is still little information about the relationship between protein expression pattern and TOF. In this study, we aimed to explore the potential linkage of proteomics and TOF development. Briefly, 121 differentially expressed proteins were identified from a TOF group, compared with a control group. The expression levels of 34 of these proteins were significantly different (>1.5 absolute fold change, p < 0.05) between the two groups. Gene ontology (GO) and pathway analysis showed that these proteins were mainly associated with carbon metabolism, biosynthesis of antibodies, positive regulation of transcription from RNA polymerase II promoter, nucleus, ATP binding, and so on. The ingenuity pathway analysis (IPA) results indicated that 435 of upstream regulators were identified of these differentially expressed proteins, which might be involved in the development of TOF. Data of string analysis showed the protein-protein interaction network among the differentially expressed proteins and regulators, which are related to TOF. In conclusion, our study explored the protein expression pattern of TOF, which might provide new insights into understanding the mechanism of TOF development and afford potential targets for TOF diagnosis and therapy.
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Affiliation(s)
- Yun Wu
- Department of Echocardiography, Nanjing First Hospital, Nanjing Medical University, Nanjing, China.,Department of Ultrasonography, Women's Hospital of Nanjing Medical University (Nanjing Maternity and Child Health Care Hospital), Nanjing, China
| | - Jingjing Zhang
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University (Nanjing Maternity and Child Health Care Hospital), Nanjing, China
| | - Mei Wang
- Department of Pathology, Nanjing Hospital of Traditional Chinese Medicine, The Third Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Ling Yang
- Department of Ultrasonography, Women's Hospital of Nanjing Medical University (Nanjing Maternity and Child Health Care Hospital), Nanjing, China
| | - Yongmei Wang
- Department of Ultrasonography, Women's Hospital of Nanjing Medical University (Nanjing Maternity and Child Health Care Hospital), Nanjing, China
| | - Tao Hu
- Department of Ultrasonography, Women's Hospital of Nanjing Medical University (Nanjing Maternity and Child Health Care Hospital), Nanjing, China
| | - An Liu
- Department of Ultrasonography, Women's Hospital of Nanjing Medical University (Nanjing Maternity and Child Health Care Hospital), Nanjing, China
| | - Qing Cheng
- Department of Ultrasonography, Women's Hospital of Nanjing Medical University (Nanjing Maternity and Child Health Care Hospital), Nanjing, China
| | - Ziyi Fu
- Department of Ultrasonography, Women's Hospital of Nanjing Medical University (Nanjing Maternity and Child Health Care Hospital), Nanjing, China
| | - Pingyang Zhang
- Department of Echocardiography, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Li Cao
- Department of Ultrasonography, Women's Hospital of Nanjing Medical University (Nanjing Maternity and Child Health Care Hospital), Nanjing, China
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Gao S, Jiang Y, Wang G, Yuan Y, Huang S, Gao X, Li X, Zhang D, Wu J, Ji X, Deng T, Wang L, Kang D, Dai P. Skewed X-chromosome inactivation and next-generation sequencing to identify a novel SMPX variants associated with X-linked hearing loss in a Chinese family. Int J Pediatr Otorhinolaryngol 2018; 113:88-93. [PMID: 30174017 DOI: 10.1016/j.ijporl.2018.07.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 07/12/2018] [Accepted: 07/13/2018] [Indexed: 10/28/2022]
Abstract
OBJECTIVE Hereditary nonsyndromic hearing loss is extremely heterogeneous and an X-linked form accounts for 1-5% of all cases. The aim of this study was to identify the pathogenic variants in a nonsyndromic X-linked dominant hearing loss family, and explain the reason of different hearing phenotype in hearing between the two sisters with the same variant. METHODS Targeted gene capture and next-generation sequencing were used to study the genetic cause. What's more, methylation differences among the androgen receptor genes were used to investigate whether the different hearing levels of the two sisters is related to X-chromosome inactivation (Xi). RESULTS We identified SMPX c.29insA (p.Asn10Lysfs*3) as the novel variant causing deafness. The skewed X-chromosome inactivation was relevant to the hearing difference between the two sisters. CONCLUSION Targeted gene capture and NGS is an efficient way to identify pathogenic variants in genes. Analysis of X-chromosome inactivation is beneficial to the diagnosis and genetic counseling of X-linked dominant hearing loss families.
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Affiliation(s)
- Song Gao
- Department of Otolaryngology-Head and Neck Surgery, Chinese PLA General Hospital, Beijing, China; Department of Otolaryngology, The 175th Hospital of PLA, South-East Hospital Affiliated to Xiamen University, Zhangzhou, China
| | - Yi Jiang
- Department of Otolaryngology, Fujian Medical University ShengLi Clinical College, Fujian Provincial Hospital, Fuzhou, China
| | - Guojian Wang
- Department of Otolaryngology-Head and Neck Surgery, Chinese PLA General Hospital, Beijing, China
| | - Yongyi Yuan
- Department of Otolaryngology-Head and Neck Surgery, Chinese PLA General Hospital, Beijing, China
| | - Shasha Huang
- Department of Otolaryngology-Head and Neck Surgery, Chinese PLA General Hospital, Beijing, China
| | - Xue Gao
- Department of Otolaryngology, The General Hospital of the PLA Rocket Force, Beijing, China
| | - Xiaohong Li
- Department of Otolaryngology-Head and Neck Surgery, Chinese PLA General Hospital, Beijing, China
| | - Dejun Zhang
- Department of Otolaryngology-Head and Neck Surgery, Chinese PLA General Hospital, Beijing, China
| | - Jian Wu
- MyGenostics Inc., Beijing, China
| | | | - Tao Deng
- Beijing Capital Bio Independent Clinical Laboratory, Beijing, PR China
| | - Ligang Wang
- Beijing Capital Bio Independent Clinical Laboratory, Beijing, PR China
| | - Dongyang Kang
- Department of Otolaryngology-Head and Neck Surgery, Chinese PLA General Hospital, Beijing, China
| | - Pu Dai
- Department of Otolaryngology-Head and Neck Surgery, Chinese PLA General Hospital, Beijing, China.
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8
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A novel mutation in the SMPX gene associated with X-linked nonsyndromic sensorineural hearing loss in a Chinese family. J Hum Genet 2018; 63:723-730. [PMID: 29559740 DOI: 10.1038/s10038-018-0443-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Revised: 02/05/2018] [Accepted: 03/01/2018] [Indexed: 12/19/2022]
Abstract
X-linked inheritance is very rare and is estimated to account for only 1-5% of all nonsyndromic hearing loss cases. We found a multiplex family from China segregating with X-linked nonsyndromic hearing loss. After exclusive analysis of 10 common variations of three hearing loss-related genes, GJB2, mtDNA12srRNA and SLC26A4, a novel truncated variant of SMPX, c.87dupA (p.Gly30Argfs*12) (NCBI ClinVar Submission ID: SUB3136126), was identified by whole-exome sequencing. This variant was co-segregated with hearing loss in the entire family and was absent in 576 unrelated ethnically and geographically matched controls. We also detected a single nucleotide variation in two male controls with normal hearing, SMPX c.55A>G (p.Asn19Asp), which has been annotated as a rare variant in the Single Nucleotide Polymorphism (dbSNP) (rs759552778) and Exome Aggregation Consortium (ExAC) databases. This study has enriched the mutation spectrum of the SMPX gene.
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Mittal R, Patel AP, Nguyen D, Pan DR, Jhaveri VM, Rudman JR, Dharmaraja A, Yan D, Feng Y, Chapagain P, Lee DJ, Blanton SH, Liu XZ. Genetic basis of hearing loss in Spanish, Hispanic and Latino populations. Gene 2018; 647:297-305. [PMID: 29331482 PMCID: PMC5806531 DOI: 10.1016/j.gene.2018.01.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 01/02/2018] [Accepted: 01/06/2018] [Indexed: 12/13/2022]
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.
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Affiliation(s)
- Rahul Mittal
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Amit P Patel
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Desiree Nguyen
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Debbie R Pan
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Vasanti M Jhaveri
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Jason R Rudman
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Arjuna Dharmaraja
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Denise Yan
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Yong Feng
- Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, China
| | - Prem Chapagain
- Department of Physics and Biomolecular Sciences Institute, Florida International University, Miami, FL, USA
| | - David J Lee
- Department of Public Health Sciences, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Susan H Blanton
- 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
| | - Xue Zhong Liu
- 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.
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10
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Niu Z, Yan D, Bressler S, Mei L, Feng Y, Liu X. A novel splicing mutation in SMPX is linked to nonsyndromic progressive hearing loss. Int J Pediatr Otorhinolaryngol 2018; 104:47-50. [PMID: 29287879 DOI: 10.1016/j.ijporl.2017.10.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 10/25/2017] [Accepted: 10/25/2017] [Indexed: 10/18/2022]
Abstract
OBJECTIVE X-linked nonsyndromic hearing impairment is the rarest form of genetic hearing loss and represents only a minor fraction of all cases. The aim of this study was to investigate the cause of X-linked nonsyndromic sensorineural hearing loss in a three-generation American family. METHODS Whole-exome sequencing and co-segregation analysis were used to identify disease-causing genes. RESULTS In this study, we described in detail the clinical characteristics of the family and identified a novel frameshift mutation creating a premature stop codon (c.133-1 G > A, p.(Gly45fs*36)) of SMPX. The loss-of-function mutation was co-segregated with the progressive hearing loss phenotype and was absent in 200 normal controls. CONCLUSIONS We report the first SMPX (DFNX4) mutation in a North American family. Our findings contribute to the existing genotypic and phenotypic spectrum of SMPX associated hearing loss. Furthermore, our data suggest that exome sequencing is promising in the genetic diagnosis of hearing loss.
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Affiliation(s)
- Zhijie Niu
- Department of Otolaryngology-Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha 410008, China; Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Denise Yan
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Sara Bressler
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Lingyun Mei
- Department of Otolaryngology-Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Yong Feng
- Department of Otolaryngology-Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha 410008, China.
| | - Xuezhong Liu
- Department of Otolaryngology-Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha 410008, China; Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
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11
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Niu Z, Feng Y, Mei L, Sun J, Wang X, Wang J, Hu Z, Dong Y, Chen H, He C, Liu Y, Cai X, Liu X, Jiang L. A novel frameshift mutation of SMPX causes a rare form of X-linked nonsyndromic hearing loss in a Chinese family. PLoS One 2017; 12:e0178384. [PMID: 28542515 PMCID: PMC5444825 DOI: 10.1371/journal.pone.0178384] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 05/11/2017] [Indexed: 01/12/2023] Open
Abstract
X-linked hearing impairment is the rarest form of genetic hearing loss (HL) and represents only a minor fraction of all cases. The aim of this study was to investigate the cause of X-linked inherited sensorineural HL in a four-generation Chinese family. A novel duplication variant (c.217dupA, p.Ile73Asnfs*5) in SMPX was identified by whole-exome sequencing. The frameshift mutation predicted to result in the premature truncation of the SMPX protein was co-segregated with the HL phenotype and was absent in 295 normal controls. Subpopulation screening of the coding exons and flanking introns of SMPX was further performed for 338 Chinese patients with nonsydromic HL by Sanger sequencing, and another two potential causative substitutions (c.238C>A and c.55A>G) in SMPX were identified in additional sporadic cases of congenital deafness. Collectively, this study is the first to report the role of SMPX in Chinese population and identify a novel frameshift mutation in SMPX that causes not only nonsyndromic late-onset progressive HL, but also congenital hearing impairment. Our findings extend the mutation and phenotypic spectrum of the SMPX gene.
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Affiliation(s)
- Zhijie Niu
- Department of Otolaryngology-Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, PR China
- Key Laboratory of Otolaryngology Major Disease Research of Hunan Province, Changsha, PR China
- Department of Otolaryngology (D-48), University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - Yong Feng
- Department of Otolaryngology-Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, PR China
- Key Laboratory of Otolaryngology Major Disease Research of Hunan Province, Changsha, PR China
- State Key Laboratory of Medical Genetics, Central South University, Changsha, PR China
| | - Lingyun Mei
- Department of Otolaryngology-Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, PR China
- Key Laboratory of Otolaryngology Major Disease Research of Hunan Province, Changsha, PR China
| | - Jie Sun
- Department of Otolaryngology-Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, PR China
- Key Laboratory of Otolaryngology Major Disease Research of Hunan Province, Changsha, PR China
| | - Xueping Wang
- Department of Otolaryngology-Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, PR China
- Key Laboratory of Otolaryngology Major Disease Research of Hunan Province, Changsha, PR China
| | - Juncheng Wang
- Department of Otolaryngology-Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, PR China
- Key Laboratory of Otolaryngology Major Disease Research of Hunan Province, Changsha, PR China
| | - Zhengmao Hu
- State Key Laboratory of Medical Genetics, Central South University, Changsha, PR China
| | - Yunpeng Dong
- Department of Otolaryngology (D-48), University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - Hongsheng Chen
- Department of Otolaryngology-Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, PR China
- Key Laboratory of Otolaryngology Major Disease Research of Hunan Province, Changsha, PR China
| | - Chufeng He
- Department of Otolaryngology-Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, PR China
- Key Laboratory of Otolaryngology Major Disease Research of Hunan Province, Changsha, PR China
| | - Yalan Liu
- Department of Otolaryngology-Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, PR China
- Key Laboratory of Otolaryngology Major Disease Research of Hunan Province, Changsha, PR China
| | - Xinzhang Cai
- Department of Otolaryngology-Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, PR China
- Key Laboratory of Otolaryngology Major Disease Research of Hunan Province, Changsha, PR China
| | - Xuezhong Liu
- Department of Otolaryngology-Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, PR China
- Department of Otolaryngology (D-48), University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - Lu Jiang
- Department of Otolaryngology-Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, PR China
- Key Laboratory of Otolaryngology Major Disease Research of Hunan Province, Changsha, PR China
- * E-mail:
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12
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The nuclear receptor NOR-1 regulates the small muscle protein, X-linked (SMPX) and myotube differentiation. Sci Rep 2016; 6:25944. [PMID: 27181368 PMCID: PMC4867575 DOI: 10.1038/srep25944] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 04/25/2016] [Indexed: 01/12/2023] Open
Abstract
Recent works have highlighted the role of NOR-1 in both smooth and skeletal muscle, and have proposed this nuclear receptor as a nexus that coordinates muscle performance and metabolic capacity. However, no muscle specific genes regulated by NOR-1 have been identified so far. To identify NOR-1 target genes, we over-expressed NOR-1 in human vascular smooth muscle cells (VSMC). These cells subjected to sustained over-expression of supraphysiological levels of NOR-1 experienced marked phenotypic changes and up-regulated the skeletal muscle protein X-linked (SMPX), a protein typically expressed in striated muscle and associated to cell shape. By transcriptional studies and DNA-protein binding assays, we identified a non-consensus NBRE site in human SMPX promoter, critical for NOR-1 responsiveness. The expression of SMPX was higher in human skeletal muscle myoblasts (HSMM) than in human VSMC, and further increased in HSMM differentiated to myotubes. NOR-1 silencing prevented SMPX expression in HSMM, as well as their differentiation to myotubes, but the up-regulation of SMPX was dispensable for HSMM differentiation. Our results indicate that NOR-1 regulate SMPX in human muscle cells and acts as a muscle regulatory factor, but further studies are required to unravel its role in muscle differentiation and hypertrophy.
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13
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Egilmez OK, Kalcioglu MT. Genetics of Nonsyndromic Congenital Hearing Loss. SCIENTIFICA 2016; 2016:7576064. [PMID: 26989561 PMCID: PMC4775805 DOI: 10.1155/2016/7576064] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 01/19/2016] [Indexed: 06/05/2023]
Abstract
Congenital hearing impairment affects nearly 1 in every 1000 live births and is the most frequent birth defect in developed societies. Hereditary types of hearing loss account for more than 50% of all congenital sensorineural hearing loss cases and are caused by genetic mutations. HL can be either nonsyndromic, which is restricted to the inner ear, or syndromic, a part of multiple anomalies affecting the body. Nonsyndromic HL can be categorised by mode of inheritance, such as autosomal dominant (called DFNA), autosomal recessive (DFNB), mitochondrial, and X-linked (DFN). To date, 125 deafness loci have been reported in the literature: 58 DFNA loci, 63 DFNB loci, and 4 X-linked loci. Mutations in genes that control the adhesion of hair cells, intracellular transport, neurotransmitter release, ionic hemeostasis, and cytoskeleton of hair cells can lead to malfunctions of the cochlea and inner ear. In recent years, with the increase in studies about genes involved in congenital hearing loss, genetic counselling and treatment options have emerged and increased in availability. This paper presents an overview of the currently known genes associated with nonsyndromic congenital hearing loss and mutations in the inner ear.
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Affiliation(s)
- Oguz Kadir Egilmez
- Department of Otorhinolaryngology, Faculty of Medicine, Istanbul Medeniyet University, 34722 Istanbul, Turkey
| | - M. Tayyar Kalcioglu
- Department of Otorhinolaryngology, Faculty of Medicine, Istanbul Medeniyet University, 34722 Istanbul, Turkey
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14
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Eftestøl E, Alver TN, Gundersen K, Bruusgaard JC. Overexpression of SMPX in adult skeletal muscle does not change skeletal muscle fiber type or size. PLoS One 2014; 9:e99232. [PMID: 24936977 PMCID: PMC4060999 DOI: 10.1371/journal.pone.0099232] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 05/12/2014] [Indexed: 01/12/2023] Open
Abstract
Mechanical factors such as stretch are thought to be important in the regulation of muscle phenotype. Small muscle protein X-linked (SMPX) is upregulated by stretch in skeletal muscle and has been suggested to serve both as a transcription factor and a mechanosensor, possibly giving rise to changes in both fiber size and fiber type. We have used in vivo confocal imaging to study the subcellular localization of SMPX in skeletal muscle fibers of adult rats using a SMPX-EGFP fusion protein. The fusion protein was localized predominantly in repetitive double stripes flanking the Z-disc, and was excluded from all nuclei. This localization would be consistent with SMPX being a mechanoreceptor, but not with SMPX playing a role as a transcription factor. In vivo overexpression of ectopic SMPX in skeletal muscle of adult mice gave no significant changes in fiber type distribution or cross sectional area, thus a role of SMPX in regulating muscle phenotype remains unclear.
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Affiliation(s)
- Einar Eftestøl
- Department of Biosciences, University of Oslo, Oslo, Norway
| | | | | | - Jo C. Bruusgaard
- Department of Biosciences, University of Oslo, Oslo, Norway
- Atlantis Medical University College, Oslo, Norway
- * E-mail:
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15
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HOWELL MARK, GREEN RYAN, KILLEEN ALEXIS, WEDDERBURN LAMAR, PICASCIO VINCENT, RABIONET ALEJANDRO, PENG ZHENLING, LARINA MAYA, XUE BIN, KURGAN LUKASZ, UVERSKY VLADIMIRN. NOT THAT RIGID MIDGETS AND NOT SO FLEXIBLE GIANTS: ON THE ABUNDANCE AND ROLES OF INTRINSIC DISORDER IN SHORT AND LONG PROTEINS. J BIOL SYST 2013. [DOI: 10.1142/s0218339012400086] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Intrinsically disordered proteins or proteins with disordered regions are very common in nature. These proteins have numerous biological functions which are complementary to the biological activities of traditional ordered proteins. A noticeable difference in the amino acid sequences encoding long and short disordered regions was found and this difference was used in the development of length-dependent predictors of intrinsic disorder. In this study, we analyze the scaling of intrinsic disorder in eukaryotic proteins and investigate the presence of length-dependent functions attributed to proteins containing long disordered regions.
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Affiliation(s)
- MARK HOWELL
- Department of Molecular Medicine, College of Medicine, University of South Florida, Tampa, FL 33612, USA
| | - RYAN GREEN
- Department of Molecular Medicine, College of Medicine, University of South Florida, Tampa, FL 33612, USA
| | - ALEXIS KILLEEN
- Department of Molecular Medicine, College of Medicine, University of South Florida, Tampa, FL 33612, USA
| | - LAMAR WEDDERBURN
- Department of Molecular Medicine, College of Medicine, University of South Florida, Tampa, FL 33612, USA
| | - VINCENT PICASCIO
- Department of Molecular Medicine, College of Medicine, University of South Florida, Tampa, FL 33612, USA
| | - ALEJANDRO RABIONET
- Department of Molecular Medicine, College of Medicine, University of South Florida, Tampa, FL 33612, USA
| | - ZHENLING PENG
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada
| | - MAYA LARINA
- Department of Mathematics and Informatics, College of Medical Biochemistry, Volgograd State Medical University, 400131 Volgograd, Russia
| | - BIN XUE
- Department of Molecular Medicine, College of Medicine, University of South Florida, Tampa, FL 33612, USA
| | - LUKASZ KURGAN
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada
| | - VLADIMIR N. UVERSKY
- Department of Molecular Medicine, USF Health Byrd Alzheimer's Research Institute, College of Medicine, University of South Florida, Tampa, FL 33612, USA
- Institute for Biological Instrumentation, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia
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16
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Abdelfatah N, Merner N, Houston J, Benteau T, Griffin A, Doucette L, Stockley T, Lauzon JL, Young TL. A novel deletion in SMPX causes a rare form of X-linked progressive hearing loss in two families due to a founder effect. Hum Mutat 2012; 34:66-9. [PMID: 22911656 DOI: 10.1002/humu.22205] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Accepted: 07/31/2012] [Indexed: 12/31/2022]
Abstract
X-linked hearing loss is the rarest form of genetic hearing loss contributing to <1% of cases. We identified a multiplex family from Newfoundland (Family 2024) segregating X-linked hearing loss. Haplotyping of the X chromosome and sequencing of positional candidate genes revealed a novel point deletion (c.99delC) in SMPX which encodes a small muscle protein responsible for reducing mechanical stress during muscle contraction. This novel deletion causes a frameshift and a premature stop codon (p.Arg34GlufsX47). We successfully sequenced both SMPX wild-type and mutant alleles from cDNA of a lymphoblastoid cell line, suggesting that the mutant allele may not be degraded via nonsense-mediated mRNA decay. To investigate the role of SMPX in other subpopulations, we fully sequenced SMPX in 229 Canadian probands with hearing loss and identified a second Newfoundland Family (2196) with the same mutation, and a shared haplotype on the X chromosome, suggesting a common ancestor.
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Affiliation(s)
- Nelly Abdelfatah
- Faculty of Medicine, Memorial University, St John's, Newfoundland and Labrador, Canada
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17
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Schraders M, Haas SA, Weegerink NJD, Oostrik J, Hu H, Hoefsloot LH, Kannan S, Huygen PLM, Pennings RJE, Admiraal RJC, Kalscheuer VM, Kunst HPM, Kremer H. Next-generation sequencing identifies mutations of SMPX, which encodes the small muscle protein, X-linked, as a cause of progressive hearing impairment. Am J Hum Genet 2011; 88:628-34. [PMID: 21549342 DOI: 10.1016/j.ajhg.2011.04.012] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2011] [Revised: 04/07/2011] [Accepted: 04/18/2011] [Indexed: 01/12/2023] Open
Abstract
In a Dutch family with an X-linked postlingual progressive hearing impairment, a critical linkage interval was determined to span a region of 12.9 Mb flanked by the markers DXS7108 and DXS7110. This interval overlaps with the previously described DFNX4 locus and contains 75 annotated genes. Subsequent next-generation sequencing (NGS) detected one variant within the linkage interval, a nonsense mutation in SMPX. SMPX encodes the small muscle protein, X-linked (SMPX). Further screening was performed on 26 index patients from small families for which X-linked inheritance of nonsyndromic hearing impairment (NSHI) was not excluded. We detected a frameshift mutation in SMPX in one of the patients. Segregation analysis of both mutations in the families in whom they were found revealed that the mutations cosegregated with hearing impairment. Although we show that SMPX is expressed in many different organs, including the human inner ear, no obvious symptoms other than hearing impairment were observed in the patients. SMPX had previously been demonstrated to be specifically expressed in striated muscle and, therefore, seemed an unlikely candidate gene for hearing impairment. We hypothesize that SMPX functions in inner ear development and/or maintenance in the IGF-1 pathway, the integrin pathway through Rac1, or both.
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Affiliation(s)
- Margit Schraders
- Department of Otorhinolaryngology, Head and Neck Surgery, Nijmegen, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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18
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Huebner A, Gandia M, Frommolt P, Maak A, Wicklein E, Thiele H, Altmüller J, Wagner F, Viñuela A, Aguirre L, Moreno F, Maier H, Rau I, Gießelmann S, Nürnberg G, Gal A, Nürnberg P, Hübner C, del Castillo I, Kurth I. Nonsense mutations in SMPX, encoding a protein responsive to physical force, result in X-chromosomal hearing loss. Am J Hum Genet 2011; 88:621-7. [PMID: 21549336 DOI: 10.1016/j.ajhg.2011.04.007] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 04/08/2011] [Accepted: 04/11/2011] [Indexed: 01/12/2023] Open
Abstract
The fact that hereditary hearing loss is the most common sensory disorder in humans is reflected by, among other things, an extraordinary allelic and nonallelic genetic heterogeneity. X-chromosomal hearing impairment represents only a minor fraction of all cases. In a study of a Spanish family the locus for one of the X-chromosomal forms was assigned to Xp22 (DFNX4). We mapped the disease locus in the same chromosomal region in a large German pedigree with X-chromosomal nonsyndromic hearing impairment by using genome-wide linkage analysis. Males presented with postlingual hearing loss and onset at ages 3-7, whereas onset in female carriers was in the second to third decades. Targeted DNA capture with high-throughput sequencing detected a nonsense mutation in the small muscle protein, X-linked (SMPX) of affected individuals. We identified another nonsense mutation in SMPX in patients from the Spanish family who were previously analyzed to map DFNX4. SMPX encodes an 88 amino acid, cytoskeleton-associated protein that is responsive to mechanical stress. The presence of Smpx in hair cells and supporting cells of the murine cochlea indicates its role in the inner ear. The nonsense mutations detected in the two families suggest a loss-of-function mechanism underlying this form of hearing impairment. Results obtained after heterologous overexpression of SMPX proteins were compatible with this assumption. Because responsivity to physical force is a characteristic feature of the protein, we propose that long-term maintenance of mechanically stressed inner-ear cells critically depends on SMPX function.
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19
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Ren ZQ, Xiong YZ, Deng CY, Lei MG. Cloning and identification of porcine SMPX differentially expressed in F1 crossbreds and their parents. Acta Biochim Biophys Sin (Shanghai) 2006; 38:753-8. [PMID: 17091191 DOI: 10.1111/j.1745-7270.2006.00229.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
In order to investigate porcine heterosis on the molecular basis, Large White (L), a European purebred, and Meishan (M), a Chinese indigenous purebred, were hybridized directly and reciprocally to produce F1 hybrids, Large WhitexMeishan (LM) and MeishanxLarge White (ML) pigs. Using mRNA differential display, we found an expression sequence tag (EST) differentially expressed in F1 hybrids and their parents, designated as EST55, which was homologous to human and murine skeletal muscle protein (SMPX), and the full-length cDNA of porcine SMPX was cloned by the rapid amplification of cDNA end (RACE) method. Translation of the mRNA transcript revealed an open reading frame (ORF) of 86 amino acid residues encoding a nuclear location signal peptide, two overlapping casein kinase II phosphorylation sites and one N-glycosylation site with theoretical molecular weight of 9.3 kDa. Alignment analysis revealed that the deduced protein sequence shared 94%, 83% and 78% homology with that of its human, mouse and rat counterparts, respectively. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that it was expressed predominantly in skeletal and heart muscles, whereas at a moderate level in backfat, spleen, stomach and uterus tissues. Two single nucleotide polymorphism (SNPs), located in 5'- and 3'-untranslated region (UTR), respectively,were identified by PCR and sequencing. Phylogenetic tree and the secondary structure prediction were also performed. The possible relationship between porcine SMPX and heterosis was discussed.
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Affiliation(s)
- Zhu-Qing Ren
- Agricultural Ministry Key Laboratory of Swine Breeding and Genetics, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
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20
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Schindeler A, Lavulo L, Harvey RP. Muscle costameric protein, Chisel/Smpx, associates with focal adhesion complexes and modulates cell spreading in vitro via a Rac1/p38 pathway. Exp Cell Res 2005; 307:367-80. [PMID: 15893749 DOI: 10.1016/j.yexcr.2005.04.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2005] [Revised: 04/07/2005] [Accepted: 04/09/2005] [Indexed: 10/25/2022]
Abstract
The murine X-linked gene Chisel (Csl/Smpx) encodes a 9-kDa protein that associates in heart and skeletal muscle cells with the costameric cytoskeleton, implicated in maintaining muscle integrity and responses to biomechanical stress. After expression in C2C12 myoblasts, MYC epitope-tagged Csl co-localized with actin networks at peripheral membranes, and with focal adhesion proteins vinculin, paxillin, integrin beta1, and the small GTPase Rac1. Csl could be co-immunoprecipitated with vinculin from extracts of C2C12 cells and native muscle. MYC-Csl induced cell spreading and lamellipodia formation in C2C12 cells at the expense of filopodia, suggestive of modulation of Rac1 activity. Lamellipodia formation was indeed Rac1-dependent, and in MYC-Csl cells replated on fibronectin, Rac1 activity was increased relative to controls. Expression of MYC-Csl led to an increased association between vinculin and p34, a subunit of the Arp2/3 actin nucleation complex, a Rac1-dependent event. Induced cell spreading was also dependent upon p38 kinases that act downstream of Rac1 to control the actin capping activity of heat shock protein 27. Our data suggest that Csl localizes to the costameric cytoskeleton of muscle cells through an association with focal adhesion proteins, where it may participate in regulation of cytoskeletal dynamics through the Rac1-p38 pathway.
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Affiliation(s)
- Aaron Schindeler
- Developmental Biology Program, Victor Chang Cardiac Research Institute, 384 Victoria Street, Darlinghurst NSW 2010, Australia
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21
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Abstract
A plethora of new 'omics such as transcriptomics, proteomics, metabolomics (or metabonomics), pharmacogenomics, physiomics and cytomics are upon us, but can histochemistry be an 'omic? To be an 'omic a technique must take a 'global' and 'holistic' view of biology that addresses biological complexity head-on by synthesising multiparameter data into predictive models. Thus to be an 'omic, a histochemical technique should be as inclusive as possible in identifying as many targets as possible with equal likelihood and sensitivity of detection. Any technique capable of detecting only one or two targets is not within the spirit of an 'omic, ruling out it seems most of histochemistry. Nevertheless, new developments in high-throughput histochemistry and cytochemistry are making powerful claims to the title 'Histocytomics'. Histocytomics and all the other 'omics are components of the only real 'omic 'Biomics', that is, the integrated application of science into a coherent strategy for understanding biological complexity. In this paper, this strategy is presented for the investigation of the regulation of phenotypic change in skeletal and cardiac muscle in health and disease.
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Affiliation(s)
- Gary Coulton
- Department of Basic Medical Sciences and Department of Cardiac and Vascular Sciences, St. George's Hospital Medical School, Cranmer Terrace, London, SW17 0RE, UK
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22
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Kränkel N, Adams V, Gielen S, Linke A, Erbs S, Schuler G, Hambrecht R. Differential gene expression in skeletal muscle after induction of heart failure: impact of cytokines on protein phosphatase 2A expression. Mol Genet Metab 2003; 80:262-71. [PMID: 14567976 DOI: 10.1016/s1096-7192(03)00132-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Different intrinsic alterations of skeletal muscle metabolism and gene expression have been described in chronic heart failure (CHF). As proposed skeletal muscle alterations in CHF may contribute to exercise intolerance and early muscular fatigue. However the exact molecular changes occurring in the skeletal muscle are still unclear. The aim of this study was to characterize the pattern of differential gene expression in an animal model of CHF and to study the regulation of one selected gene. Rats were subjected to LAD ligation or sham operation. mRNA was isolated from musculus quadriceps of both groups and differential gene expression was determined by subtractive hybridization. Quantitative RT-PCR and cell culture experiments were performed to further characterize the changed expression of protein phosphatase 2A (PP2A) in human skeletal muscle biopsies as well as the cytokine dependent regulation of PP2A expression. Out of 800 picked clones differential expression of 24 distinct genes could be identified by sequencing and reverse Northern blotting. PP2A expression demonstrated a significant upregulation in skeletal muscle biopsies from patients with CHF as compared to healthy controls (9.7 +/- 1.9 vs. 4.2 +/- 0.7 arbitrary units; p<0.05). Incubation of rat skeletal muscle myoblasts with a combination of TNF-alpha, IL-1beta, and gamma-IFN caused a 3-fold upregulation of PP2A expression vs. untreated cells. These results suggest that CHF is accompanied by changes in expression of genes involved in energy metabolism, contractility, and apoptosis in the skeletal muscle. The upregulation of PP2A, an important regulator in intracellular signaling and apoptosis, may be due to an increase of inflammatory cytokines.
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Affiliation(s)
- Nicolle Kränkel
- Department of Cardiology, Heart Center, University of Leipzig, D-04289 Leipzig, Germany
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23
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Palmer S, Groves N, Schindeler A, Yeoh T, Biben C, Wang CC, Sparrow DB, Barnett L, Jenkins NA, Copeland NG, Koentgen F, Mohun T, Harvey RP. The small muscle-specific protein Csl modifies cell shape and promotes myocyte fusion in an insulin-like growth factor 1-dependent manner. J Cell Biol 2001; 153:985-98. [PMID: 11381084 PMCID: PMC2174333 DOI: 10.1083/jcb.153.5.985] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We have isolated a murine cDNA encoding a 9-kD protein, Chisel (Csl), in a screen for transcriptional targets of the cardiac homeodomain factor Nkx2-5. Csl transcripts were detected in atria and ventricles of the heart and in all skeletal muscles and smooth muscles of the stomach and pulmonary veins. Csl protein was distributed throughout the cytoplasm in fetal muscles, although costameric and M-line localization to the muscle cytoskeleton became obvious after further maturation. Targeted disruption of Csl showed no overt muscle phenotype. However, ectopic expression in C2C12 myoblasts induced formation of lamellipodia in which Csl protein became tethered to membrane ruffles. Migration of these cells was retarded in a monolayer wound repair assay. Csl-expressing myoblasts differentiated and fused normally, although in the presence of insulin-like growth factor (IGF)-1 they showed dramatically enhanced fusion, leading to formation of large dysmorphogenic "myosacs." The activities of transcription factors nuclear factor of activated T cells (NFAT) and myocyte enhancer-binding factor (MEF)2, were also enhanced in an IGF-1 signaling-dependent manner. The dynamic cytoskeletal localization of Csl and its dominant effects on cell shape and behavior and transcription factor activity suggest that Csl plays a role in the regulatory network through which muscle cells coordinate their structural and functional states during growth, adaptation, and repair.
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Affiliation(s)
- Steve Palmer
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
| | - Nicola Groves
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
| | - Aaron Schindeler
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
| | - Thomas Yeoh
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
| | - Christine Biben
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
| | - Cheng-Chun Wang
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
| | - Duncan B. Sparrow
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
| | - Louise Barnett
- Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3050, Australia
| | - Nancy A. Jenkins
- Mouse Cancer Genetics Program, National Cancer Institute-Frederick, Frederick, Maryland 21702
| | - Neal G. Copeland
- Mouse Cancer Genetics Program, National Cancer Institute-Frederick, Frederick, Maryland 21702
| | - Frank Koentgen
- Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3050, Australia
| | - Tim Mohun
- Medical Research Council Institute for Medical Research, London NW7 1AA, United Kingdom
| | - Richard P. Harvey
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
- Faculties of Medicine and Life Sciences, University of New South Wales, Kensington, NSW 2051, Australia
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24
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Kemp TJ, Sadusky TJ, Simon M, Brown R, Eastwood M, Sassoon DA, Coulton GR. Identification of a novel stretch-responsive skeletal muscle gene (Smpx). Genomics 2001; 72:260-71. [PMID: 11401441 DOI: 10.1006/geno.2000.6461] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Skeletal muscle is able to respond to a range of stimuli, including stretch and increased load, by increasing in diameter and length in the absence of myofiber division. This type of cellular growth (hypertrophy) is a highly complex process involving division of muscle precursor cells (myoblasts) and their fusion to existing muscle fibers as well as increased protein synthesis and decreased protein degradation. Underlying the alterations in protein levels are increases in a range of specific mRNAs including those coding for structural proteins and proteins that regulate the hypertrophic process. Seven days of passive stretch in vivo of tibialis anterior (TA) muscle has been shown to elicit muscle hypertrophy. We have identified a cDNA corresponding to an mRNA that exhibits increased expression in response to 7 days of passive stretch imposed on TA muscles in vivo. This 944-bp novel murine transcript is expressed primarily in cardiac and skeletal muscle and to a lesser extent in brain. Translation of the transcript revealed an open reading frame of 85 amino acids encoding a nuclear localization signal and two overlapping casein kinase II phosphorylation sites. This gene has been called "small muscle protein (X chromosome)" (Smpx; HGMW-approved human gene symbol SMPX) and we hypothesize that it plays a role in skeletal muscle hypertrophy.
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MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Blotting, Western
- Cell Differentiation/genetics
- Chromosome Mapping
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- Embryo, Mammalian/metabolism
- Exons
- Gene Expression Regulation
- Gene Expression Regulation, Developmental
- Humans
- Immunohistochemistry
- Introns
- Male
- Mice
- Mice, Inbred C57BL
- Molecular Sequence Data
- Muscle Proteins
- Muscle, Skeletal/cytology
- Muscle, Skeletal/metabolism
- Porins/genetics
- Porins/metabolism
- Promoter Regions, Genetic/genetics
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Specific Pathogen-Free Organisms
- Stress, Mechanical
- Tissue Distribution
- X Chromosome/genetics
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Affiliation(s)
- T J Kemp
- Molecular Pathology, Imperial College of Science, Technology, and Medicine, London, SW7 2AZ, United Kingdom.
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