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Successful visualization of prostate cancer (PCa) tumor margins during surgery remains a major challenge. The visualization of these tumors during surgery via near infrared fluorescence (NIRF) imaging would greatly enhance surgical resection, minimizing tumor recurrence and improving outcome. Furthermore, chemotherapy is typically administered to patients after surgery to treat any missed tumor tissue around the surgical area, minimizing metastasis and increasing patient survival. For these reasons, a theranostics fluorescent nanoparticle could be developed to assist in the visualization of PCa tumor margins, while also delivering chemotherapeutic drug after surgery. Methods: Ferumoxytol (FMX) conjugated to the fluorescent dye and PCa targeting agent, heptamethine carbocyanine (HMC), yielded the HMC-FMX nanoprobe that was tested in vitro with various PCa cell lines and in vivo with both subcutaneous and orthotopic PCa mouse models. Visualization of these tumors via NIRF imaging after administration of HMC-FMX was performed. In addition, delivery of chemotherapeutic drug and their effect on tumor growth was also assessed. Results: HMC-FMX internalized into PCa cells, labeling these cells and PCa tumors in mice with near infrared fluorescence, facilitating tumor margin visualization. HMC-FMX was also able to deliver drugs to these tumors, reducing cell migration and slowing down tumor growth. Conclusion: HMC-FMX specifically targeted PCa tumors in mice allowing for the visualization of tumor margins by NIRF imaging. Furthermore, delivery of anticancer drugs by HMC-FMX effectively reduced prostate tumor growth and reduced cell migration in vitro . Thus, HMC-FMX can potentially translate into the clinic as a nanotheranostics agent for the intraoperative visualization of PCa tumor margins, and post-operative treatment of tumors with HMC-FMX loaded with anticancer drugs., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Despite significant efforts to improve glioblastoma multiforme (GBM) treatment, GBM remains one of the most lethal cancers. Effective GBM treatments require sensitive intraoperative tumor visualization and effective postoperative chemotherapeutic delivery. Unfortunately, the diffusive and infiltrating nature of GBM limits the detection of GBM tumors, and current intraoperative visualization methods limit complete tumor resection. In addition, although chemotherapy is often used to eliminate any cancerous tissue remaining after surgery, most chemotherapeutic drugs do not effectively cross the brain-blood barrier (BBB) or enter GBM tumors. As a result, GBM has limited treatment options with high recurrence rates, and methods that improve its complete visualization during surgery and treatment are needed. Herein, we report a fluorescent nanoparticle platform for the near-infrared fluorescence (NIRF)-based tumor boundary visualization and image-guided drug delivery into GBM tumors. Our nanoplatform is based on ferumoxytol (FMX), an FDA-approved magnetic resonance imaging-sensitive superparamagnetic iron oxide nanoparticle, which is conjugated with hepthamethine cyanine (HMC), a NIRF ligand that specifically targets the organic anion transporter polypeptides that are overexpressed in GBM. We have shown that HMC-FMX nanoparticles cross the BBB and selectively accumulate in the tumor using orthotopic GBM mouse models, enabling NIRF-based visualization of infiltrating tumor tissue. In addition, HMC-FMX can encapsulate chemotherapeutic drugs, such as paclitaxel or cisplatin, and deliver these agents into GBM tumors, reducing tumor size and increasing survival. Taken together, these observations indicate that HMC-FMX is a promising nanoprobe for GBM surgical visualization and drug delivery.

Clusterin (CLU) is an extracellular chaperone protein that is implicated in diverse physiological and pathophysiological cellular processes. CLU expression is upregulated in response to cellular stress and under certain conditions, such as neurodegenerative disease and cancer. CLU primarily functions as a chaperone that exerts cytoprotective effects by removing cellular debris and misfolded proteins and also acts as a signaling molecule that regulates pro-survival pathways. Deafness is caused by genetic factors and various extrinsic insults, including ototoxic drugs, exposure to loud sounds and aging. Considering its cytoprotectivity, CLU may also mediate cellular defense mechanisms against hearing loss due to cellular stresses. To understand the function of CLU in the inner ear, we analyze CLU expression patterns in the mouse inner ear during development and in the adult stage. Results of quantitative real-time polymerase chain reaction analysis showed that Clu mRNA levels in the inner ear were increased during embryogenesis and were constantly expressed in the adult. Detailed spatial expression patterns of Clu both in the mRNA and protein levels were analyzed throughout various developmental stages via in situ hybridization and immunofluorescence staining. Clu expression was found in specific domains of developing inner ear starting from the otocyst stage, mainly adjacent to the prosensory domain of the cochlear epithelium. In the mature inner ear, Clu expression was observed in Deiter's cells and pillar cells of the organ of Corti, outer sulcus and in basal cells of the stria vascularis in the cochlea. These specific spatiotemporal expression patterns suggest the possible roles of CLU in inner ear development and in maintaining proper hearing function.

Hair cells in the cochlea display highly regulated actin polymerization, which is mediated by the human diaphanous-related formin 1 gene (DIAPH1; also called DFNA1, DIA1). DFNA1, the first type of autosomal dominant nonsyndromic hearing loss (ADNSHL), is known to be associated with mutations in DIAPH1. However, no genetic study of DFNA1 in Koreans with hearing loss has yet been reported. A 51-year-old patient in a Korean family with ADNSHL was examined by pure-tone audiometry, and genetic analysis of DIAPH1 was performed. A novel variant, p.I530S (c.1589T > G), was identified in the DIAPH1 gene, and the mutation was located in the highly conserved coiled-coil domain of the DIA1 protein, where an amino acid substitution was predicted to change the domain structure. Further functional investigations will provide more information to help us understand the role of DIAPH1 in maintenance of hair cell function in the auditory pathway.

Objectives: We aimed to identify the causative mutation for siblings in a Korean family with nonsyndromic hearing loss (HL) and enlarged vestibular aqueduct (EVA). The siblings were a 19-year-old female with bilateral profound HL and an 11-year-old male with bilateral moderately severe HL., Methods: We extracted genomic DNA from blood samples of the siblings with HL, their parents, and 100 controls. We performed mutation analysis for SLC26A4 using direct sequencing., Results: The two siblings were compound heterozygotes with the novel mutation p.I713LfsX8 and the previously described mutation p.H723R. Their parents had heterozygous mono-allelic mutations. Father had p.I713LfsX8 mutation as heterozygous, and mother had p.H723R mutation as heterozygous. However, novel mutation p.I713LfsX8 was not detected in 100 unrelated controls., Conclusion: Both mutations identified in this study were located in the sulfate transporter and anti-sigma factor antagonist domain, the core region for membrane targeting of SulP/SLC26 anion transporters, which strongly suggests that failure in membrane trafficking by SLC26A4 is a direct cause of HL in this family. Our study could therefore provide a foundation for further investigations elucidating the SLC26A4 -related mechanisms of HL.

Background: Myosin is a key protein involved in regulating the shape and motility of cells. The MYH9 and MYH14 genes, which encode non-muscle myosin heavy chain IIA (NMMHC II-A) and IIC (NMMHC II-C), respectively, are expressed in the inner ear. These myosin genes are known to be associated with autosomal dominant non-syndromic hearing loss (ADNSHL); however, genetic studies in patients with ADNSHL in Korea have rarely been reported., Methods: We analyzed the MYH9 and MYH14 genes in 75 Korean patients with ADNSHL., Results: We identified 4 possible pathogenic variants: a novel variant p.F1303L and 2 previously reported variants (p.R1730C and p.R1785C) in the MYH9 gene, and a novel variant p.A1868T in the MYH14 gene. All the variants were located in the myosin tail domain, which is essential for the interaction of myosin with actin. These variants were predicted to be possibly pathogenic by functional prediction tools and were absent in 100 unrelated normal controls., Conclusion: These results suggest that all the variants identified in this study have a strong potential to affect the structural stability and/or function of non-muscle myosin in the inner ear, which might lead to ADNSHL. This study establishes the link between the genotype and development of ADNSHL and contributes to the establishment of Korean database for hereditary hearing loss., (Copyright © 2016. Published by Elsevier B.V.)

Familial paraganglioma (PGL) is a dominantly inherited disorder characterized by development of PGLs in the head and neck region. Germline mutations in genes coding for succinate dehydrogenase (SDH) subunits D, B, and C (SDHD, SDHB, SDHC) are found in almost all familial PGL patients. A 19-year-old female presented with pulsatile tinnitus and a reddish pulsating mass in the external auditory canal, and her mother complained of similar symptoms. Paraganglioma was found in both patients and was surgically removed. We report a case of germline SDHB mutation. This mutation was a deletion of thymine at nucleotide position 757 in exon 7 of the SDHB gene (c.757delT).

We have investigated transcriptional and epigenetic differences in peripheral blood mononuclear cells (PBMCs) of monozygotic female twins discordant in the diagnosis of amyotrophic lateral sclerosis (ALS). Exploring DNA methylation differences by reduced representation bisulfite sequencing (RRBS), we determined that, over time, the ALS twin developed higher abundances of the CD14 macrophages and lower abundances of T cells compared to the non-ALS twin. Higher macrophage signature in the ALS twin was also shown by RNA sequencing (RNA-seq). Moreover, the twins differed in the methylome at loci near several genes, including EGFR and TNFRSF11A, and in the pathways related to the tretinoin and H3K27me3 markers. We also tested cytokine production by PBMCs. The ALS twin's PBMCs spontaneously produced IL-6 and TNF-α, whereas PBMCs of the healthy twin produced these cytokines only when stimulated by superoxide dismutase (SOD)-1. These results and flow cytometric detection of CD45 and CD127 suggest the presence of memory T cells in both twins, but effector T cells only in the ALS twin. The ALS twin's PBMC supernatants, but not the healthy twin's, were toxic to rat cortical neurons, and this toxicity was strongly inhibited by an IL-6 receptor antibody (tocilizumab) and less well by TNF-α and IL-1β antibodies. The putative neurotoxicity of IL-6 and TNF-α is in agreement with a high expression of these cytokines on infiltrating macrophages in the ALS spinal cord. We hypothesize that higher macrophage abundance and increased neurotoxic cytokines have a fundamental role in the phenotype and treatment of certain individuals with ALS.-Lam, L., Chin, L., Halder, R. C., Sagong, B., Famenini, S., Sayre, J., Montoya, D., Rubbi L., Pellegrini, M., Fiala, M. Epigenetic changes in T-cell and monocyte signatures and production of neurotoxic cytokines in ALS patients., (© FASEB.)

Most cases of CHARGE syndrome are sporadic and autosomal dominant. CHD7 is a major causative gene of CHARGE syndrome. In this study, we screened CHD7 in two Turkish patients demonstrating symptoms of CHARGE syndrome such as coloboma, heart defect, choanal atresia, retarded growth, genital abnomalities and ear anomalies. Two mutations of CHD7 were identified including a novel splice-site mutation (c.2443-2A>G) and a previously known frameshift mutation (c.2504_2508delATCTT). We performed exon trapping analysis to determine the effect of the c.2443-2A>G mutation at the transcriptional level, and found that it caused a complete skip of exon 7 and splicing at a cryptic splice acceptor site. Our current study is the second study demonstrating an exon 7 deficit in CHD7. Results of previous studies suggest that the c.2443-2A>G mutation affects the formation of nasal tissues and the neural retina during early development, resulting in choanal atresia and coloboma, respectively. The findings of the present study will improve our understanding of the genetic causes of CHARGE syndrome., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Background: One of the causes of sensorineural hearing loss (SNHL) is degeneration of the inner hair cells in the organ of Corti in the cochlea. The SLC17A8 (solute carrier family 17, member 8) gene encodes vesicular glutamate transporter 3 (VGLUT3), and among its isoforms (VGLUT1-3), only VGLUT3 is expressed selectively in the inner hair cells (IHCs). VGLUT3 transports the neurotransmitter glutamate into the synaptic vesicles of the IHCs. Mutation of the SLC17A8 gene is reported to be associated with DFNA25 (deafness, autosomal dominant 25), an autosomal dominant non-syndromic hearing loss (ADNSHL) in humans., Methods: In this study, we performed a genetic analysis of 87 unrelated Korean patients with ADNSHL to determine whether the SLC17A8 gene affects hearing ability in the Korean population., Results: We found a novel heterozygous frameshift mutation, 2 non-synonymous variations, and a synonymous variation. The novel frameshift mutation, p.M206Nfs*4, in which methionine is changed to asparagine at amino acid position 206, resulted in a termination codon at amino acid position 209. This alteration is predicted to encode a truncated protein lacking transmembrane domains 5 to 12. This mutation is located in a highly conserved region in VGLUT3 across multiple amino acid alignments in different vertebrate species, but it was not detected in 100 unrelated controls who had normal hearing ability. The results from our study suggest that the p.M206Nfs*4 mutation in the SLC17A8 gene is likely a pathogenic mutation that causes ADNSHL., Conclusion: Our findings can facilitate the prediction of the primary cause of ADNSHL in Korean patients.

Hereditary hearing loss is a heterogeneous disorder that results in a common sensorineural disorder. To date, more than 150 loci and 89 genes have been reported for non-syndromic hearing loss. Next generation sequencing has recently been developed as a powerful genetic strategy for identifying pathogenic mutations in heterogeneous disorders with various causative genes. In this study, we performed targeted sequencing to identify the causative mutation in a Korean family that had moderate hearing loss. We targeted 64 genes associated with non-syndromic hearing loss and sorted the homozygous variations according to the autosomal recessive inheritance pattern of the family. Implementing a bioinformatic platform for filtering and detecting variations allowed for the identification of two variations within different genes (c.650G>A in TRIOBP and c.4057C>T in STRC). These variants were selected for further analysis. Among these, c.4057C>T (p.Q1353X) was a divergent sequence variation between the STRC gene and the STRC pseudogene. This was the critical difference that resulted in loss of the protein-coding ability of the pseudogene. Therefore, we hypothesized that the p.Q1353X variation in the STRC gene is the causative mutation for hearing loss. This result suggests that application of targeted sequencing will be valuable for the diagnosis of heterogeneous disorders., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Sporadic ALS patients display heterogeneous immune pathways in peripheral blood mononuclear cells (PBMCs). We tested nine sALS patients and one unaffected identical twin of an index case by RNA-Seq of PBMCs. The inflammatory patients (n = 3) clustered into a subset with an inflammatory Th1/Th17 signature and the non-inflammatory patients (n = 7) into another subset with a B cell signature. The inflammatory subset was remarkable for granulocyte and agranulocyte diapedesis, hepatic fibrosis, roles of cytokines and metalloproteases. The non-inflammatory subset was highlighted by degradation of vitamin E, serotonin and nucleotides, altered T cell and B cell signaling, agranulocyte diapedesis, and up regulation of B cell genes. Identification of these differentially regulated pathways in sALS patients may guide the choice of anti-inflammatory therapies.

We investigated the effects of 4-17 month supplementation with ω-3 fatty acids and antioxidants (Smartfish drink; Smartfish AS, Oslo, Norway) in 12 patients with minor cognitive impairment (MCI) [minimental state examination (MMSE) ≥19], 2 patients with pre-MCI (normal MMSE), and 7 patients with Alzheimer disease (AD) (MMSE <19). We measured the phagocytosis of amyloid-β 1-42 (Aβ) by flow cytometry and microscopy, the transcription of inflammatory genes by RT-PCR, the production of resolvin D1 (RvD1) by enzyme immunoassay, and the cognitive status by MMSE. In patients with MCI and pre-MCI, phagocytosis of Aβ by monocytes increased from 530 to 1306 mean fluorescence intensity units (P = 0.016). The increase in patients with AD was not significant (N.S.). The lipidic mediator RvD1, which stimulates Aβ phagocytosis in vitro, increased in macrophages in 80% of patients with MCI and pre-MCI (mean increase 9.95 pg/ml) (N.S.). Transcription of inflammatory genes' mRNAs was increased in a subgroup of patients with low transcription at baseline, whereas it was not significantly changed in patients with high transcription at baseline. The mean MMSE score of patients with MCI and pre-MCI was 25.9 at baseline and 25.7 after 4-17 months (N.S.). Our study is the first to show significant immune and biochemical effects of ω-3 fatty acids with antioxidants in patients with MCI. Cognitive benefits of ω-3 supplementation in patients with MCI should be tested in a clinical trial., (© FASEB.)

Pancreatic cancer has a poor prognosis attributed in part to immune suppression and deactivation of natural killer (NK) cells. Curcuminoids have a potential for improving the therapy of pancreatic cancer given promising results in cancer models and a clinical trial, but their oral absorption is limited. Our objective in this study is to show curcuminoid anti-oncogenic effects alone and together with human NK cells. We tested curcuminoids in an emulsion of ω-3 fatty acids and anti-oxidants ("Smartfish") regarding their direct cytocidal effect and enhancement of the cytocidal activity of NK cells in pancreatic ductal adenocarcinoma (PDAC) cells (Mia Paca 2 and L3.6). Curcuminoids (at ≥10 μM) with ω-3 fatty acids and anti-oxidants or with the lipidic mediator resolvin D1 (RvD1) (26 nM) induced high caspase-3 activity in PDAC cells. Importantly, curcuminoids with ω-3 fatty acids and anti-oxidants or with RvD1 significantly potentiated NK cell cytocidal function and protected them against degradation. In a co-culture of cancer cells with NK cells, interferon-γ (IFN-γ) production by NK cells was not altered by ω-3 fatty acids with anti-oxidants or by RvD1 but was inhibited by curcuminoids. The inhibition was not eliminated by ω-3 fatty acids or RvD1 but was relieved by removing curcuminoids after adding NK cells. In conclusion, curcuminoids with ω-3 fatty acids and anti-oxidants or with RvD1 have increased cytotoxic activity on PDAC cells alone and with NK cells. The effects of curcuminoids with ω-3 fatty acids and anti-oxidants on pancreatic cancer will be investigated in a mouse model with humanized immune system.

EYA4 and GRHL2 encode transcription factors that play an important role in regulating many developmental stages. Since EYA4 and GRHL2 were identified as the transcription factors for the DFNA10 and DFNA28, 8 EYA4 mutations and 2 GRHL2 mutations have been reported worldwide. However, these genes have been reported in few studies of the Korean population. In this study, we performed a genetic analysis of EYA4 and GRHL2 in 87 unrelated Korean patients with autosomal dominant non-syndromic hearing loss (NSHL). A total of 4 genetic variants in the EYA4 gene were identified, including the 2 nonsense mutations p.S288X and p.Q393X. The novel mutation p.Q393X (c.1177C>T) resulted in a change in the codon at amino acid position 393 from a glutamine to a stop codon. The p.Q393X allele was predicted to encode a truncated protein lacking the entire C-terminal Eya homolog region (Eya HR), which is essential for the interaction with the transcription factor SIX3. The p.S288X (c.863C>A) mutation was found in a Korean family from a previous study. We analyzed p.S288X-linked microsatellite markers and determined that p.S288X might be a founder mutation and a hotspot mutation in Koreans. In GRHL2, a total of 4 genetic variants were identified, but none were associated with hearing loss in Korean patients. This suggests that GRHL2 may not be a main causal gene for autosomal dominant NSHL in Korean patients. In conclusion, our data provide fundamental information to predict the genotypes of Korean patients diagnosed with autosomal dominant NSHL.

Hearing loss (HL) is genetically heterogeneous and can be caused by mutations in multiple gene lesions. Pendred syndrome, caused by mutation of SLC26A4, is one of the common causes of recessive syndromic profound HL. Mitochondrial mutation is another rare cause of genetic HL, resulting in late onset sensorineural HL. Recently, we evaluated a young woman representing bilateral progressive moderate HL with delayed language development, along with her family. Hearing test, temporal bone computed tomography, and genetic evaluation of GJB2, MT-RNR1, SLC26A4 gene mutations were performed on each family member. Her mother was prelingually deaf and displayed enlarged vestibular aqueduct (EVA) along with goiter. Interestingly, subject's mother showed both SLC26A4 mutation and mitochondrial A1555G heteroplasmic mutation at the same time. The sisters did not display EVA or goiter. Although the subject's older sister showed both prelingual deafness and mitochondrial A1555G heteroplasmy, her younger sister showed only A1555G homoplasmy, which suggests A1555G homoplasmy as the genetic cause of hearing loss. This is the first report of HL caused by mitochondrial A1555G homoplasmy from a mother with Pendred syndrome coexistent with A1555G heteroplasmy in the Korean population., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Craniosynostosis is a heterogeneous disorder that results in a common malformation which causes premature fusion of one or more cranial sutures. Whole-exome sequencing (WES) was recently developed as a powerful genetic strategy for identifying pathogenic mutations of heterogeneous disorders with various causative genes. A 24-year-old woman visited our department for evaluation of persistent hearing impairment and absence of an external auditory canal from birth. In this study, we performed WES to identify the causative mutation in a Korean family who has Crouzon Syndrome (CS). We first focused on 16 genes associated with craniosynostosis and sorted the heterozygous variations according to the autosomal dominant inheritance pattern of her family. After the bioinformatic analysis for filtering and detecting variations, three non-synonymous variations in different genes were selected for additional analysis. Among these, the p.C278F mutation in the FGFR2 gene was only absent from both dbSNP and the 1000 Genomes database. We considered the p.C278F mutation in the FGFR2 gene as the causative mutation for the CS. This result suggests that the application of WES will be valuable for diagnosis of congenital disorders with clinical and genetics heterogeneities., (© 2014 by the Association of Clinical Scientists, Inc.)

Pannexins (Panx) are a family of proteins that share sequences with the invertebrate gap junction proteins, innexins, and have a similar structure to that of the vertebrate gap junction proteins, connexins. To date, the Panx family consists of 3 members, but their genetic sequences have only been completely determined in a few vertebrate species. Moreover, expression of the Panx family has been reported in several rodent tissues: Panx1 is ubiquitously expressed in mammals, whereas Panx2 and Panx3 expressions are more restricted. Although members of the Panx family have been detected in mammals, their genetic sequences in avian species have not yet been fully elucidated. Here, we obtained the full-length mRNA sequences of chicken PANX genes and evaluated the homology of the amino acids from these sequences with those of other species. Furthermore, PANX gene expression in several chicken tissues was investigated based on mRNA levels. PANX1 was detected in the brain, cochlea, chondrocytes, eye, lung, skin, and intestine, and PANX2 was expressed in the brain, eye, and intestine. PANX3 was observed in the cochlea, chondrocytes, and bone. In addition, expression of PANX3 was higher than PANX1 in the cochlea. Immunofluorescent staining revealed PANX1 in hair cells, as well as the supporting cells, ganglion neurons, and the tegmentum vasculosum in chickens, whereas PANX3 was only detected in the bone surrounding the cochlea. Overall, the results of this study provide the first identification and characterization of the sequence and expression of the PANX family in an avian species, and fundamental data for confirmation of Panx function., (© 2014 Poultry Science Association Inc.)

Cisplatin is an effective antineoplastic drug that is widely used to treat various cancers; however, it causes side effects such as ototoxicity via the induction of apoptosis of hair cells in the cochlea. Alpha-lipoic acid (ALA) has been reported to exert a protective effect against both antibiotic-induced and cisplatin-induced hearing loss. Therefore, this study was conducted to (1) elucidate the mechanism of the protective effects of ALA against cisplatin-induced ototoxicity using in vitro and ex vivo culture systems of HEI-OC1 auditory cells and rat cochlear explants and (2) to gain additional insight into the apoptotic mechanism of cisplatin-induced ototoxicity. ALA pretreatment significantly reduced apoptotic cell death of the inner and outer hair cells in cisplatin-treated organ of Corti explants and attenuated ototoxicity via marked inhibition of the increase in the expression of IL-1β and IL-6, the phosphorylation of ERK and p38, the degradation of IκBα, the increase in intracellular levels of ROS, and the activation of caspase-3 in cisplatin-treated HEI-OC1 cells. This study represents the first histological evaluation of the organ of Corti following treatment with ALA, and these results indicate that the protective effects of ALA against cisplatin-induced ototoxicity are mediated via the regulation of MAPKs and proinflammatory cytokines., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Tight junctions (TJs) are essential components of eukaryotic cells, and serve as paracellular barriers and zippers between adjacent tissues. TJs are critical for normal functioning of the organ of Corti, a part of the inner ear that causes loss of sensorineural hearing when damaged. To investigate the relation between genes involved in TJ function and hereditary loss of sensorineural hearing in the Korean population, we selected the TJP2 and CLDN14 genes as candidates for gene screening of 135 Korean individuals. The TJP2 gene, mutation of which causes autosomal dominant non-syndromic hearing loss (ADNSHL), lies at the DFNA51 locus on chromosome 9. The CLDN14 gene, mutation of which causes autosomal recessive non-syndromic hearing loss (ARNSHL), lies at the DFNB29 locus on chromosome 21. In the present study, we conducted genetic analyses of the TJP2 and CLDN14 genes in 87 unrelated patients with ADNSHL and 48 unrelated patients with either ARNSHL or potentially sporadic hearing loss. We identified two pathogenic variations, c.334G>A (p.A112T) and c.3562A>G (p.T1188A), and ten single nucleotide polymorphisms (SNPs) in the TJP2 gene. We found eight non-pathogenic variations in the CLDN14 gene. These findings indicate that, whereas mutation of the TJP2 gene might cause ADNSHL, CLDN14 is not a major causative gene for ARNSHL in the Korean population studied. Our findings may improve the understanding of the genetic cause of non-syndromic hearing loss in the Korean population.

Sensitivity to phenylthiocarbamide (PTC) has a bimodal distribution pattern and the genotype of the TAS2R38 gene, which is composed of combinations of three coding single nucleotide polymorphisms (SNPs), p.A49P (c.145G>C), p.V262A (c.785T>C) and p.I296 V (c.886A>G), determines the ability or inability to taste PTC. In this study, we developed a tool for genotyping of these SNPs in the TAS2R38 gene using SNaPshot minisequencing and investigated the accuracy of the tool in 100 subjects who were genotyped by Sanger sequencing. The minor allele frequencies of the three SNPs were 0.39, and these genotypes corresponded to those determined by direct sequencing. In conclusion, we successfully developed a precise and rapid genetic tool for analysis of PTC genotype associated with bitter taste perception.

Background: The genetic heterogeneity of hearing loss makes genetic diagnosis expensive and time consuming using available methods. Whole-exome sequencing has recently been introduced as an alternative approach to identifying causative mutations in Mendelian disorders., Methods: To identify the hidden mutations that cause autosomal recessive nonsyndromic hearing loss (ARNSHL), we performed whole-exome sequencing of 13 unrelated Korean small families with ARNSHL who were negative for GJB2 or SLC26A4 mutations., Results: We found two novel compound heterozygous mutations, IVS11 + 1 and p.R2146Q, of MYO15A in one (SR903 family) of the 13 families with ARNSHL. In addition to these causative mutations, 13 nonsynonymous variants, including variants with uncertain pathogenicity (SR285 family), were identified in the coding exons of MYO15A from Korean exomes., Conclusion: This is the first report of MYO15A mutations in an East Asian population. We suggest that close attention should be paid to this gene when performing genetic testing of patients with hearing loss in East Asia. The present results also indicate that whole-exome sequencing is a valuable method for comprehensive medical diagnosis of a genetically heterogeneous recessive disease, especially in small-sized families.

Background: Carbonic anhydrases (CAs), which catalyze CO(2) hydration to bicarbonate and protons, have been suggested to regulate potassium homeostasis and endocochlear potential in the mammalian cochlea. Sixteen mammalian CA isozymes are currently known. To understand the specific roles of CA isozymes in the inner ear, a systematic survey was conducted to reveal temporal and spatial expression patterns of all 16 CA isozymes during inner ear development., Results: Our quantitative reverse transcriptase-polymerase chain reaction results showed that different tissues express unique combinations of CA isozymes. During inner ear development, transcripts of four cytosolic isozymes (Car1, Car2, Car3, and Car13), two membrane-bound isozymes (Car12 and Car14), and two CA-related proteins (Car8 and Car11) were expressed at higher levels than other isozymes. Spatial expression patterns of these isozymes within developing inner ears were determined by in situ hybridization. Each isozyme showed a unique expression pattern during development. For example, Car12 and Car13 expression closely overlapped with Pendrin, an anion exchanger, while Car2 overlapped with Na-K-ATPase in type II and IV otic fibrocytes, suggesting functional relationships in the inner ear., Conclusions: The temporal and spatial expression patterns of each CA isozyme suggest unique and differential roles in inner ear development and function., (Copyright © 2012 Wiley Periodicals, Inc.)

Hearing loss (HL) is a congenital disease with a high prevalence, and patients with hearing loss need early diagnosis for treatment and prevention. The GJB2, MT-RNR1, and SLC26A4 genes have been reported as common causative genes of hearing loss in the Korean population and some mutations of these genes are the most common mutations associated with hearing loss. Accordingly, we developed a method for the simultaneous detection of seven mutations (c.235delC of GJB2, c.439A>G, c.919-2A>G, c.1149+3A>G, c.1229C>T, c.2168A>G of SLC26A4, and m.1555A>G of the MT-RNR1 gene) using multiplex SNaPshot minisequencing to enable rapid diagnosis of hereditary hearing loss. This method was confirmed in patients with hearing loss and used for genetic diagnosis of controls with normal hearing and neonates. We found that 4.06% of individuals with normal hearing and 4.32% of neonates were heterozygous carriers. In addition, we detected that an individual is heterozygous for two different mutations of GJB2 and SLC26A4 gene, respectively and one normal hearing showing the heteroplasmy of m.1555A>G. These genotypes corresponded to those determined by direct sequencing. Overall, we successfully developed a robust and cost-effective diagnosis method that detects common causative mutations of hearing loss in the Korean population. This method will be possible to detect up to 40% causative mutations associated with prelingual HL in the Korean population and serve as a useful genetic technique for diagnosis of hearing loss for patients, carriers, neonates, and fetuses.

Pendred syndrome (PS) is an autosomal recessive disorder characterized by congenital bilateral sensorineural hearing loss, goiter, and incomplete iodide organification. Patients with PS also have structural anomalies of the inner ear such as enlarged vestibular aqueducts (EVA) and Mondini's malformation. The goiter, which is a major clinical manifestation of PS, usually develops around adolescence. PS is caused by biallelic mutations of the SLC26A4 gene, while nonsyndromic bilateral EVA is associated with zero or one SLC26A4 mutant allele. We report here a Korean family including a young female with PS who had goiter and progressive, fluctuating sensorineural hearing loss that could be partially recovered by oral steroid treatment. Genetic investigation revealed compound heterozygous mutations for p.R677AfsX11, a novel frameshift mutation, and p.H723R in the SLC26A4 gene. Our findings provide detailed information regarding the distribution of mutant alleles for PS and may serve as a foundation for studies to comprehend the genetic portion of syndromic hearing loss., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Mutations of the TECTA gene, which encodes alpha-tectorin, are associated with both dominant (DFNA8/A12) and recessive (DFNB 21) modes of inherited nonsyndromic sensorineural hearing loss, respectively. Although clinical data and genetic analysis for TECTA gene have been reported from different groups, there is no report that compound heterozygous mutations in the TECTA gene result in nonsyndromic sensorineural hearing loss. Here, we identified a missense mutation (p.C1691F) and a splicing mutation (c.6162+3insT), one in each TECTA allele, in the patient with hearing loss. Also, we demonstrated that the splicing mutation results in the abnormal skipping of an exon, which leads to a truncated protein as determined by exon-trapping analysis. To the best of our knowledge, this is the first report of an in vitro functional study of splice site mutations in the TECTA gene., (Copyright © 2011 Elsevier B.V. All rights reserved.)

The TECTA gene, which encodes alpha-tectorin, is known as a causative gene for DFNA8/DFNA12, and DFNB21 hearing loss in humans. In the present study, mutation analysis of the TECTA gene was performed in 62 Korean patients with hereditary hearing loss. Two novel nucleotide substitutions, p.V317E and p.T1866M, were identified for the first time in the Korean population. These mutations result in the substitution of amino acids in the zonadhesin (ZA) and the zona pellucida (ZP) domains, and show a genotype-phenotype correlation, which is a characteristic of TECTA-related mutations in autosomal dominant nonsyndromic hearing loss. Both mutations are located in highly conserved regions of alpha-tectorin and were not found in 120 unrelated control subjects with normal hearing. Based on this evidence, it is likely that both mutations are the pathogenic ones causing the hearing loss. This study provides useful information for the functional study of hereditary hearing loss caused by tectorial membrane defects.