Audiological Features and Mitochondrial DNA Sequence in a Large Family Carrying Mitochondrial A1555G Mutation without Use of Aminoglycoside

2005 ◽  
Vol 114 (2) ◽  
pp. 153-160 ◽  
Author(s):  
Tatsuo Matsunaga ◽  
Hiroshi Kumanomido ◽  
Yu-ichi Goto ◽  
Masae Shiroma ◽  
Shin-ichi Usami
Keyword(s):  
Hearing Loss ◽  
Mitochondrial Dna ◽  
Dna Sequences ◽  
Large Family ◽  
Outer Hair Cells ◽  
Japanese Family ◽  
A1555g Mutation ◽  
Genetic Mechanisms ◽  
High Degree ◽  
Sibling Group

To elucidate the pathophysiological and genetic mechanisms of hearing loss associated with the homoplasmic mitochondrial A1555G mutation in the absence of aminoglycoside exposure, we conducted audiological and genetic analyses on 67 maternally related members of a large Japanese family carrying this mutation. A consistent pattern was evident in the audiograms, with features of sensory presbycusis, cochlear origin at all levels of hearing loss, and a high degree of vulnerability of outer hair cells. That the degree of hearing loss was similar in affected subjects within the same sibling group but differed between sibling groups suggests the involvement of nuclear modifier genes. Total mitochondrial DNA sequences were completely identical among subjects with various levels of hearing loss, and lacked additional pathogenic mutations. For the diagnosis of sensorineural hearing loss, the mitochondrial A1555G mutation should be considered when these features are present even in the absence of aminoglycoside exposure.

scholarly journals Phylogenetic analysis of mitochondrial DNA in Japanese pedigrees of sensorineural hearing loss associated with the A1555G mutation

1998 ◽  
Vol 6 (6) ◽  
pp. 563-569 ◽  
Author(s):  
Satoko Abe ◽  
Shin-ichi Usami ◽  
Hideichi Shinkawa ◽  
MikeD Weston ◽  
LarryD Overbeck ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Hearing Loss ◽  
Mitochondrial Dna ◽  
Sensorineural Hearing Loss ◽  
Sensorineural Hearing ◽  
A1555g Mutation

scholarly journals Mitochondrial non-syndromic sensorineural hearing loss: a clinical, audiological and pathological study from Italy, and revision of the literature

2008 ◽  
Vol 28 (1) ◽  
pp. 49-59 ◽  
Author(s):  
Stefano Berrettini ◽  
Francesca Forli ◽  
Susanna Passetti ◽  
Anna Rocchi ◽  
Luca Pollina ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Mitochondrial Dna ◽  
Sensorineural Hearing Loss ◽  
Hearing Impairment ◽  
Sensorineural Hearing ◽  
Pathological Study ◽  
Mtdna Mutations ◽  
A1555g Mutation ◽  
Sensorineural Hearing Impairment

Over the last decade, a number of distinct mutations in the mtDNA (mitochondrial DNA) have been found to be associated with both syndromic and non-syndromic forms of hearing impairment. Their real incidence as a cause of deafness is poorly understood and generally underestimated. Among the known mtDNA mutations, the A1555G mutation in the 12S gene has been identified to be one of the most common genetic cause of deafness, and it has been described to be both associated to non-syndromic progressive SNHL (sensorineural hearing loss) and to aminoglycoside-induced SNHL. In the present study, we have investigated the presence of mtDNA alterations in patients affected by idiopathic non-syndromic SNHL, both familiar and sporadic, in order to evaluate the frequency of mtDNA alterations as a cause of deafness and to describe the audiological manifestations of mitochondrial non-syndromic SNHL. In agreement with previous studies, we found the A1555G mutation to be responsible for a relevant percentage (5.4%) of cases affected with isolated idiopathic sensorineural hearing impairment.

scholarly journals Mitochondrial DNA A1555G mutation screening using a testing kit method and its significance in preventing aminoglycoside-related hearing loss

2006 ◽  
Vol 1 (1) ◽  
pp. 61-64
Author(s):  
Liu Xin ◽  
Dai Pu ◽  
Huang Deliang ◽  
Yuan Huijun ◽  
Li Weiming ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Mitochondrial Dna ◽  
Mutation Screening ◽  
A1555g Mutation

scholarly journals A Comprehensive Phylogenetic and Bioinformatics Survey of Lectins in the Fungal Kingdom

2021 ◽  
Vol 7 (6) ◽  
pp. 453
Author(s):  
Annie Lebreton ◽  
François Bonnardel ◽  
Yu-Cheng Dai ◽  
Anne Imberty ◽  
Francis M. Martin ◽  
...  
Keyword(s):  
Evolutionary Relationship ◽  
Large Family ◽  
Gene Families ◽  
Carbohydrate Binding ◽  
Sequence Motifs ◽  
Fungal Lectin ◽  
Quaternary Structures ◽  
High Degree ◽  
Carbohydrate Ligand ◽  
Fungal Kingdom

Fungal lectins are a large family of carbohydrate-binding proteins with no enzymatic activity. They play fundamental biological roles in the interactions of fungi with their environment and are found in many different species across the fungal kingdom. In particular, their contribution to defense against feeders has been emphasized, and when secreted, lectins may be involved in the recognition of bacteria, fungal competitors and specific host plants. Carbohydrate specificities and quaternary structures vary widely, but evidence for an evolutionary relationship within the different classes of fungal lectins is supported by a high degree of amino acid sequence identity. The UniLectin3D database contains 194 fungal lectin 3D structures, of which 129 are characterized with a carbohydrate ligand. Using the UniLectin3D lectin classification system, 109 lectin sequence motifs were defined to screen 1223 species deposited in the genomic portal MycoCosm of the Joint Genome Institute. The resulting 33,485 putative lectin sequences are organized in MycoLec, a publicly available and searchable database. These results shed light on the evolution of the lectin gene families in fungi.

scholarly journals Ultrasound Microbubbles Enhance the Efficacy of Insulin-Like Growth Factor-1 Therapy for the Treatment of Noise-Induced Hearing Loss

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3626
Author(s):  
Yi-Chun Lin ◽  
Yuan-Yung Lin ◽  
Hsin-Chien Chen ◽  
Chao-Yin Kuo ◽  
Ai-Ho Liao ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Growth Factor ◽  
Inner Ear ◽  
Outer Hair Cells ◽  
Round Window Membrane ◽  
Insulin Like Growth Factor ◽  
Noise Induced Hearing Loss ◽  
Ear Diseases ◽  
Brainstem Response ◽  
Ultrasound Microbubbles

The application of insulin-like growth factor 1 (IGF-1) to the round window membrane (RWM) is an emerging treatment for inner ear diseases. RWM permeability is the key factor for efficient IGF-1 delivery. Ultrasound microbubbles (USMBs) can increase drug permeation through the RWM. In the present study, the enhancing effect of USMBs on the efficacy of IGF-1 application and the treatment effect of USMB-mediated IGF-1 delivery for noise-induced hearing loss (NIHL) were investigated. Forty-seven guinea pigs were assigned to three groups: the USM group, which received local application of recombinant human IGF-1 (rhIGF-1, 10 µg/µL) following application of USMBs to the RWM; the RWS group, which received IGF-1 application alone; and the saline-treated group. The perilymphatic concentration of rhIGF-1 in the USM group was 1.95- and 1.67- fold of that in the RWS group, 2 and 24 h after treatment, respectively. After 5 h of 118 dB SPL noise exposure, the USM group had the lowest threshold shift in auditory brainstem response, least loss of cochlear outer hair cells, and least reduction in the number of synaptic ribbons on postexposure day 28 among the three groups. The combination of USMB and IGF-1 led to a better therapeutic response to NIHL. Two hours after treatment, the USM group had significantly higher levels of Akt1 and Mapk3 gene expression than the other two groups. The most intense immunostaining for phosphor-AKT and phospho-ERK1/2 was detected in the cochlea in the USM group. These results suggested that USMB can be applied to enhance the efficacy of IGF-1 therapy in the treatment of inner ear diseases.

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