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Noncystic fibrosis bronchiectasis is a chronic respiratory disease that carries high socioeconomic and medical burdens and is caused by diverse respiratory illnesses. To improve clinical outcomes, early recognition, active treatment of exacerbations, and prevention of further exacerbations are essential. However, evidence for the treatment and prevention of acute exacerbation of noncystic fibrosis bronchiectasis, especially in children, is lacking. Therefore, the evidence- and consensus-based guidelines for medical and nonmedical treatment strategies for noncystic fibrosis bronchiectasis in children and adolescents were developed by the Korean Academy of Pediatric Allergy and Respiratory Disease using the methods recommended by the Grading of Recommendations Assessment, Development, and Evaluation working group with evidence published through July 2, 2020. This guideline encompasses evidence-based treatment recommendations as well as expert opinions, addressing crucial aspects of the treatment and management of non-cystic fibrosis bronchiectasis in children. This includes considerations for antibiotics and airway clearance strategies, particularly in areas where evidence may be limited. Large, well-designed, and controlled studies are required to accumulate further evidence of management strategies for noncystic fibrosis bronchiectasis in children and adolescents.

Abstract Osteoporosis is a condition characterized by decreased bone mineral density (BMD) and reduced bone strength, leading to an increased risk of fractures. Here, to identify novel risk variants for susceptibility to osteoporosis-related traits, an exome-wide association study is performed with 6,485 exonic single nucleotide polymorphisms (SNPs) in 2,666 women of two Korean study cohorts. The rs2781 SNP in UBAP2 gene is suggestively associated with osteoporosis and BMD with p-values of 6.1 × 10−7 (odds ratio = 1.72) and 1.1 × 10−7 in the case-control and quantitative analyzes, respectively. Knockdown of Ubap2 in mouse cells decreases osteoblastogenesis and increases osteoclastogenesis, and knockdown of ubap2 in zebrafish reveals abnormal bone formation. Ubap2 expression is associated with E-cadherin (Cdh1) and Fra1 (Fosl1) expression in the osteclastogenesis-induced monocytes. UBAP2 mRNA levels are significantly reduced in bone marrow, but increased in peripheral blood, from women with osteoporosis compared to controls. UBAP2 protein level is correlated with the blood plasma level of the representative osteoporosis biomarker osteocalcin. These results suggest that UBAP2 has a critical role in bone homeostasis through the regulation of bone remodeling.

Idiopathic hypogonadotropic hypogonadism (IHH) is characterized by the absence of pubertal development and subsequent impaired fertility often due to gonadotropin-releasing hormone (GnRH) deficits. Exome sequencing of two independent cohorts of IHH patients identified 12 rare missense variants in POU6F2 in 15 patients. POU6F2 encodes two distinct isoforms. In the adult mouse, expression of both isoform1 and isoform2 was detected in the brain, pituitary, and gonads. However, only isoform1 was detected in mouse primary GnRH cells and three immortalized GnRH cell lines, two mouse and one human. To date, the function of isoform2 has been verified as a transcription factor, while the function of isoform1 has been unknown. In the present report, bioinformatics and cell assays on a human-derived GnRH cell line reveal a novel function for isoform1, demonstrating it can act as a transcriptional regulator, decreasing GNRH1 expression. In addition, the impact of the two most prevalent POU6F2 variants, identified in five IHH patients, that were located at/or close to the DNA-binding domain was examined. Notably, one of these mutations prevented the repression of GnRH transcripts by isoform1. Normally, GnRH transcription increases as GnRH cells mature as they near migrate into the brain. Augmentation earlier during development can disrupt normal GnRH cell migration, consistent with some POU6F2 variants contributing to the IHH pathogenesis.

Abstract Background Host tp53 mutations are frequently found during the early stages of colitis-associated colorectal cancer (CAC), but whether such mutations induce gut microbiota dysbiosis and chronic intestinal inflammation that contributes to the development of CAC, remains unknown. Results We found that zebrafish tp53 mutant larvae exhibited elevated intestinal inflammation, by monitoring the NFκB activity in the mid-distal intestines of zebrafish larvae using an NFκB:EGFP transgenic reporter line in vivo as well as neutrophil infiltration into the intestine. This inflammation was due to dysbiotic gut microbiota with reduced diversity, revealed using both 16S rRNA amplicon sequencing and a germfree larva model. In this dysbiosis, Aeromonas spp. were aberrantly enriched as major pathobionts and exhibited the capacity for aggressive colonization in tp53 mutants. Importantly, the ex-germfree experiments supported the causality of the host tp53 mutation for inducing the inflammation. Transcriptome and high-performance liquid chromatography analyses of the host gastrointestinal tracts identified dysregulated sialic acid (SA) metabolism concomitant with increased host Neu5Gc levels as the key determinant of aberrant inflammation, which was reversed by the sialidase inhibitors oseltamivir and Philippin A. Conclusions These results demonstrate a crucial role for host tp53 in maintaining symbiosis and immune homeostasis via SA metabolism. Disturbed SA metabolism via a tp53 mutation may be exploited by specific elements of the gut microbiome, eliciting both dysbiosis and inflammation. Manipulating sialometabolism may therefore provide an efficacious therapeutic strategy for tp53 mutation-induced dysbiosis, inflammation, and ultimately, related cancers. Video Abstract

Abstract Recurrent bacterial infection causes frequent bronchiectasis (BE) exacerbations. The effectiveness and safety of long-term administration of macrolides in BE remain controversial, especially in children who require minimal treatment to prevent exacerbation. We conducted this meta-analysis to determine the usefulness of long-term macrolide use in pediatric BE. We searched PubMed, Cochrane Library databases, Embase, KoreaMed, Igaku Chuo Zasshi, and Chinese National Knowledge Infrastructure databases. We identified randomized controlled trials (RCTs) which elucidated long-term macrolide treatment (≥ 4 weeks) in non-cystic fibrosis BE in children aged

For sustainable, national landscape-planning, this study focused on land cover changes, landscape analysis methods from various perspectives on the landscape, legal system analysis related to landscape planning, and analysis of a basic spatial map for landscape planning. First of all, in Korea the focus is on the aesthetic aspect of the landscape, while foreign countries look at the landscape from multiple perspectives and tried to solve the problem of landscape damage on this basis. Next, looking at the changes in land cover, it was found that the urbanized area increased significantly, but the area of agricultural land and wetlands decreased significantly due to development plans. In addition, looking at the contents of the landscape plan in terms of the legal system, the legal system of the Republic of Korea included a multifunctional aspect of the landscape, but the contents were only at the level of policy suggestions. Finally, through a review of a basic spatial map for landscape planning, it was found that among various basic spatial maps, the biotope map is highly likely to be used when establishing national landscape plans. The results of this study are meaningful in that they have not only established the concept of landscape in terms of multifunctionality but also established improvement measures in terms of legal and institutional aspects and the basic spatial map.

This study aimed to investigate the feasibility of blood-based biomarkers, including blood tumor mutation burden (bTMB), to predict atezolizumab efficacy in relapsed and advanced non-small cell lung cancer (NSCLC). Stage IV NSCLC patients who had previously received platinum-doublet chemotherapy were recruited and received 1200 mg of atezolizumab every three weeks. Blood was collected to obtain plasma cell-free DNA (cfDNA) before the first cycle (C0) and at the fourth cycle (C4). bTMB was measured by CT-ULTRA in patients with cfDNA over 10 ng. The objective response rate (ORR) of the enrolled 100 patients was 10%, and there was no difference in ORR according to bTMB (cutoff: 11.5 muts/Mb) at C0 (high bTMB: 8.1% vs. low bTMB: 11.1%). However, the C4/C0 bTMB ratio was significantly lower in the durable clinical benefit (DCB) patients. The cfDNA concentration at C0, the C4/C0 ratio of the cfDNA concentration, the highest variant allele frequency (hVAF), and the VAF standard deviation (VAFSD) were significantly lower in the DCB patients. In the multivariate analysis, a high cfDNA concentration at C0 (cutoff: 8.6 ng/mL) and a C4/C0 bTMB ratio greater than 1 were significantly associated with progression-free survival. These results suggest that baseline levels and dynamic changes of blood-based biomarkers (bTMB, cfDNA concentration, and VAFSD) could predict atezolizumab efficacy in previously treated NSCLC patients.

Objective: Mold exposure in early life may be associated with development of atopic dermatitis; however, studies of this link are inconclusive and evidence for the underlying mechanism(s) is lacking. This study identified the association between the time of mold exposure and development of atopic dermatitis and investigated the underlying mechanisms. Method: The association between atopic dermatitis and mold exposure was examined in the Cohort for Childhood Origin of Asthma and Allergic Diseases birth cohort study (n = 1446). Atopic dermatitis was diagnosed at 1 year of age by pediatric allergists. Exposure to mold was assessed by questionnaire. The Illumina MiSeq platform was used to examine the environmental mycobiome in 20 randomly selected healthy infants and 20 infants with atopic dermatitis at 36 weeks of gestation. Results: Prenatal, but not postnatal, mold exposure was significantly associated with atopic dermatitis (adjusted odds ratio, 1.36; 95% confidence interval, 1.01-1.83). Levels of total serum IgE at 1 year of age were higher in infants with atopic dermatitis exposed to mold during pregnancy than in healthy infants not exposed to mold during pregnancy (p = 0.021). The relative abundance of uncultured Ascomycota was higher in infants with atopic dermatitis than in healthy infants. The relative abundance of uncultured Ascomycota correlated with total serum IgE levels at 1 year of age (r = 0.613, p

Abstract Background Use of humidifier disinfectants (HD) at home leads to chemical airborne exposure, causing HD associated lung injury (HDLI) with high mortality. However, the lung function in children diagnosed with HDLI is not well studied. We investigated the effect of HD exposure on lung function, prognosis, and exposure characteristics associated with the lung function phenotype in children. Methods Eighty-one children diagnosed with HDLI in a nationwide cohort were tested for spirometry and diffusing capacity of the lung for carbon monoxide (DLco) from July 2013 and followed up with at five time points over 2 years. The results were compared with 122 children without HD exposure as controls. Home investigation and questionnaire analysis were conducted to assess HD inhalation exposure. Results HDLI survivor’s mean percent of predicted forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and corrected DLco were significantly lower compared with the control group. On longitudinal assessment, FVC was within the normal range, but flattened, and spirometry showed a predominantly restrictive pattern. Corrected DLco did not normalize above 80% despite increasing age. The persistently low phenotype of lung function was associated with initial exposure age, especially less than 12 months of age. Higher density HD exposure during sleep and close distance between the bed and the humidifier were significantly associated with persistently low corrected DLco. Conclusions HD exposure affects prolonged decrement in lung function, especially DLco, particularly among children who are exposed within the first year of life. These results suggested that early-life HD exposure determines long-term prognosis of lung function in children.

Nitro-oleate (10-nitro-octadec-9-enoic acid), which inhibits soluble epoxide hydrolase (sEH) by covalently adducting to C521, increases the abundance of epoxyeicosatrienoic acids (EETs) that can be health promoting, for example by lowering blood pressure or their anti-inflammatory actions. However, perhaps consistent with their impact on angiogenesis, increases in EETs may exacerbate progression of some cancers. To assess this, Lewis lung carcinoma (LLc1) cells were exposed to oleate or nitro-oleate, with the latter inhibiting the hydrolase and increasing their proliferation and migration in vitro. The enhanced proliferation induced by nitro-oleate was EET-dependent, being attenuated by the ETT-receptor antagonist 14,15-EE-5(Z)-E. LLc1 cells were engineered to stably overexpress wild-type or C521S sEH, with the latter exhibiting resistance to nitro-oleate-dependent hydrolase inhibition and the associated stimulation of tumor growth in vitro or in vivo. Nitro-oleate also increased migration in endothelial cells isolated from wild-type (WT) mice, but not those from C521S sEH knock-in (KI) transgenic mice genetically modified to render the hydrolase electrophile-resistant. These observations were consistent with nitro-oleate promoting cancer progression, and so the impact of this electrophile was examined in vivo again, but this time comparing growth of LLc1 cells expressing constitutive levels of wild-type hydrolase when implanted into WT or KI mice. Nitro-oleate inhibited tumor sEH (P

Abstract Background DYRK1A maps to the Down syndrome critical region at 21q22. Mutations in this kinase-encoding gene have been reported to cause microcephaly associated with either intellectual disability or autism in humans. Intellectual disability accompanied by microcephaly was recapitulated in a murine model by overexpressing Dyrk1a which mimicked Down syndrome phenotypes. However, given embryonic lethality in homozygous knockout (KO) mice, no murine model studies could present sufficient evidence to link Dyrk1a dysfunction with autism. To understand the molecular mechanisms underlying microcephaly and autism spectrum disorders (ASD), we established an in vivo dyrk1aa KO model using zebrafish. Methods We identified a patient with a mutation in the DYRK1A gene using microarray analysis. Circumventing the barrier of murine model studies, we generated a dyrk1aa KO zebrafish using transcription activator-like effector nuclease (TALEN)-mediated genome editing. For social behavioral tests, we have established a social interaction test, shoaling assay, and group behavior assay. For molecular analysis, we examined the neuronal activity in specific brain regions of dyrk1aa KO zebrafish through in situ hybridization with various probes including c-fos and crh which are the molecular markers for stress response. Results Microarray detected an intragenic microdeletion of DYRK1A in an individual with microcephaly and autism. From behavioral tests of social interaction and group behavior, dyrk1aa KO zebrafish exhibited social impairments that reproduce human phenotypes of autism in a vertebrate animal model. Social impairment in dyrk1aa KO zebrafish was further confirmed by molecular analysis of c-fos and crh expression. Transcriptional expression of c-fos and crh was lower than that of wild type fish in specific hypothalamic regions, suggesting that KO fish brains are less activated by social context. Conclusions In this study, we established a zebrafish model to validate a candidate gene for autism in a vertebrate animal. These results illustrate the functional deficiency of DYRK1A as an underlying disease mechanism for autism. We also propose simple social behavioral assays as a tool for the broader study of autism candidate genes.

Summary: Human embryonic stem cells (hESCs) hold great promise for the treatment of many incurable diseases. Sirtuin1 (SIRT1), a class III histone deacetylase, is abundantly expressed in hESCs and is known to regulate early differentiation and telomere elongation. Here, we show that downregulation of SIRT1 promotes cell death in hESCs, but not in differentiated cells, and the SIRT1-inhibition-mediated cell death is preceded by increased DNA damage. This increased DNA damage is at least partially due to decreased levels of DNA repair enzymes such as MSH2, MSH6, and APEX1. Furthermore, SIRT1 inhibition causes p53 activation, which eventually leads to DNA damage-induced apoptosis of hESCs. This study provides valuable insights into the mechanism of SIRT1-mediated hESC survival and should contribute to the development of safe and effective cell therapies. : Jang and colleagues show that SIRT1 downregulation in hESCs decreased the levels of DNA repair enzymes such as MSH2, MSH6, and APEX1 and increased DNA damage (in both SSBs and DSBs). The authors also demonstrate that SIRT1 inhibition induced massive cell death, caused at least partially by DNA damage-mediated p53 activation. Thus, SIRT1 contributes to genome stability and survival of hESCs. Keywords: SIRT1, maintaining DNA repair proteins, promoting DNA repair in hESC, prevention of DNA damage, SIRT1-mediated hESC survival

PurposeMacrolide resistance rate of Mycoplasma pneumoniae has rapidly increased in children. Studies on the clinical features between macrolide susceptible-M. pneumoniae (MSMP) and macrolide resistant-M. pneumoniae (MRMP) are lacking. The aim of this study was to identify the macrolide resistance rate of M. pneumoniae in Korean children with M. pneumoniae penupmonia in 2015 and compare manifestations between MSMP and MRMP.MethodsAmong 122 children (0–18 years old) diagnosed with M. pneumoniae pneumonia, 95 children with the results of macrolide sensitivity test were included in this study. Clinical manifestations were acquired using retrospective medical records.ResultsThe macrolide resistant rate of M. pneumoniae was 87.2% (82 of 94 patients) in children with M. pneumoniae pneumonia. One patient showed a mixed type of wild type and A2063G mutation in 23S rRNA of M. pneumoniae. There were no significant differences in clinical, laboratory, and radiologic findings between the MSMP and MRMP groups at the first visit to our hospital. The time interval between initiation of macrolide and defervescence was significantly longer in the MRMP group (4.9±3.3 vs. 2.8±3.1 days, P=0.039).ConclusionThe macrolide resistant rate of M. pneumoniae is very high in children with M. pneumoniae pneumonia in Korea. The clinical manifestations of MRMP are similar to MSMP except for the defervescence period after administration of macrolide. Continuous monitoring of the occurrence and antimicrobial susceptibility of MRMP is required to control its spread and establish strategies for treating second-line antibiotic resistant M. pneumoniae infection.

The development of Gonadotropin releasing hormone-1 (GnRH) neurons is important for a functional reproduction system in vertebrates. Disruption of GnRH results in hypogonadism and if accompanied by anosmia is termed Kallmann Syndrome (KS). From their origin in the nasal placode, GnRH neurons migrate along the olfactory-derived vomeronasal axons to the nasal forebrain junction and then turn caudally into the developing forebrain. Although research on the origin of GnRH neurons, their migration and genes associated with KS has identified multiple factors that influence development of this system, several aspects still remain unclear. This review discusses development of the olfactory system, factors that regulate GnRH neuron formation and development of the olfactory system, migration of the GnRH neurons from the nose into the brain, and mutations in humans with KS that result from disruption of normal GnRH/olfactory systems development.

DYRK1A is a major causative gene in Down syndrome (DS). Reduced incidence of solid tumors such as neuroblastoma in DS patients and increased vascular anomalies in DS fetuses suggest a potential role of DYRK1A in angiogenic processes, but in vivo evidence is still scarce. Here, we used zebrafish dyrk1aa mutant embryos to understand DYRK1A function in cerebral vasculature formation. Zebrafish dyrk1aa mutants exhibited cerebral hemorrhage and defects in angiogenesis of central arteries in the developing hindbrain. Such phenotypes were rescued by wild-type dyrk1aa mRNA, but not by a kinase-dead form, indicating the importance of DYRK1A kinase activity. Chemical screening using a bioactive small molecule library identified a calcium chelator, EGTA, as one of the hits that most robustly rescued the hemorrhage. Vascular defects of mutants were also rescued by independent modulation of calcium signaling by FK506. Furthermore, the transcriptomic analyses supported the alterations of calcium signaling networks in dyrk1aa mutants. Together, our results suggest that DYRK1A plays an essential role in angiogenesis and in maintenance of the developing cerebral vasculature via regulation of calcium signaling, which may have therapeutic potential for DYRK1A-related vascular diseases.

The microbiota–gut–brain axis (MGBA) is a bidirectional signaling pathway mediating the interaction of the microbiota, the intestine, and the central nervous system. While the MGBA plays a pivotal role in normal development and physiology of the nervous and gastrointestinal system of the host, its dysfunction has been strongly implicated in neurological disorders, where intestinal dysbiosis and derived metabolites cause barrier permeability defects and elicit local inflammation of the gastrointestinal tract, concomitant with increased pro-inflammatory cytokines, mobilization and infiltration of immune cells into the brain, and the dysregulated activation of the vagus nerve, culminating in neuroinflammation and neuronal dysfunction of the brain and behavioral abnormalities. In this topical review, we summarize recent findings in human and animal models regarding the roles of the MGBA in physiological and neuropathological conditions, and discuss the molecular, genetic, and neurobehavioral characteristics of zebrafish as an animal model to study the MGBA. The exploitation of zebrafish as an amenable genetic model combined with in vivo imaging capabilities and gnotobiotic approaches at the whole organism level may reveal novel mechanistic insights into microbiota–gut–brain interactions, especially in the context of neurological disorders such as autism spectrum disorder and Alzheimer’s disease.

The mechanism underlying neuroinflammation in X-linked adrenoleukodystrophy (ALD) is poorly understood. Here authors identify aberrant production of 25-hydroxycholesterol (25-HC) in ALD patient-derived cells, and show that 25-HC mediates neuroinflammation via activating the NLRP3 inflammasome.

Background: A key therapeutic approach to asthma, which is characterized by chronic airway inflammation, is inhaled corticosteroid (ICS). This study evaluated the association of symptom control with changes in lung function, bronchial hyperresponsiveness (BHR), and exhaled nitric oxide (eNO) after ICS treatment in asthmatic children. Methods: A total of 33 children aged between 5 and 12 years with mild to moderate persistent asthma were treated with 160 μg ciclesonide per day for 3 months. At days 0 and 90, the following parameters were assessed: asthma symptom scores; lung function, including forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and forced expiratory flow at 25–75% of forced vital capacity (FEF25–75%); BHR to methacholine and adenosine 5-monophosphate (AMP); and eNO. Results: Asthma symptom scores, lung function parameters, BHR to methacholine and AMP, and eNO levels at day 90 were significantly improved versus day 0 (all p

PurposeAdherence to treatment with inhaled corticosteroids (ICS) is a critical determinant of asthma control. The objective of this study was to assess factors that determine adherence to ICS therapy in children with asthma.MethodsFifty-eight children with asthma, aged 5 to 16 years, used ICS with or without a spacer for 3 months. Adherence rates as measured from questionnaires and canisters, asthma symptom scores, and inhalation technique scores were assessed every 30 days. The degree of supervision by caregivers was assessed at day 30.ResultsAdherence rates measured using canisters were lower at day 60 than at day 30 (P=0.044) and did not change thereafter (74.4%±17.4% at day 30, 66.5%±18.4% at day 60, and 67.4%±22.2% at day 90). Adherence rates at days 60 and 90 and during the total study period were significantly different when measured by using questionnaires versus canisters (P

Children who were only exposed to a mixture of chloromethylisothiazolinone (CMIT) and methylisothiazolinone (MIT) as humidifier disinfectant (HD) components were evaluated for humidifier disinfectant-associated lung injury (HDLI) from 2012. This study was to evaluate the pulmonary function using, impulse oscillometry (IOS) for children exposed to a mixture of CMIT/MIT from HD.Twenty-four children who were only exposed to a mixture of CMIT/MIT, with no previous underlying disease, were assessed by IOS. Diagnostic criteria for HDLI were categorized as definite, probable, possible, or unlikely. Home visits and administration of a standardized questionnaire were arranged to assess exposure characteristics.Definite and probable cases showed higher airborne disinfectant exposure intensity during sleep (32.4 ± 8.7 μg/m3) and younger age at initial exposure (3.5 ± 3.3 months) compared with unlikely cases (17.3 ± 11.0 μg/m3, p = 0.026; 22.5 ± 26.2 months, p = 0.039, respectively). Reactance at 5 Hz was significantly more negative in those with high-density exposure during sleep (mean, -0.463 kPa/L/s vs. low density, -0.296, p = 0.001). The reactance area was also higher with high-density exposure during sleep (mean, 3.240 kPa/L vs. low density, 1.922, p = 0.039). The mean bronchodilator response with high-density exposure was within the normal range for reactance.Significant peripheral airway dysfunction were found in children with high levels of inhalation exposure to a mixture of CMIT/MIT during sleep. Strict regulation of a mixture of CMIT/MIT exposure were associated with positive effects on lung function of children.

A silver nanoparticle is one of the representative engineered nanomaterials with excellent optical, electrical, antibacterial properties. Silver nanoparticles are being increasingly used for medical products, water filters, and cosmetics, etc. However, silver nanoparticles are known to cause adverse effects on the ecosystem and human health. To utilize silver nanoparticles with minimized negative effects, it is important to understand the behavior of silver nanoparticles released to the environment. In this study, we compared toxicity behaviors of citrate-stabilized silver nanoparticles with polyethylene glycol coated silver nanoparticles in two different ionic environments, which are aquatic environments for developing zebrafish embryo. Depending on the composition of the ionic environment, citrate-stabilized silver nanoparticles and polyethylene glycol coated silver nanoparticles exhibited different behaviors in dissolution, aggregation, or precipitation, which governed the toxicity of silver nanoparticles on zebrafish embryos.

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.

Vascular calcification is an advanced feature of atherosclerosis for which no effective therapy is available. To investigate the modulation or reversal of calcification, we identified calcifying progenitor cells and investigated their calcifying/decalcifying potentials. Cells from the aortas of mice were sorted into four groups using Sca-1 and PDGFRα markers. Sca-1(+) (Sca-1(+)/PDGFRα(+) and Sca-1(+)/PDGFRα(-)) progenitor cells exhibited greater osteoblastic differentiation potentials than Sca-1(-) (Sca-1(-)/PDGFRα(+) and Sca-1(-)/PDGFRα(-)) progenitor cells. Among Sca-1(+) progenitor populations, Sca-1(+)/PDGFRα(-) cells possessed bidirectional differentiation potentials towards both osteoblastic and osteoclastic lineages, whereas Sca-1(+)/PDGFRα(+) cells differentiated into an osteoblastic lineage unidirectionally. When treated with a peroxisome proliferator activated receptor γ (PPARγ) agonist, Sca-1(+)/PDGFRα(-) cells preferentially differentiated into osteoclast-like cells. Sca-1(+) progenitor cells in the artery originated from the bone marrow (BM) and could be clonally expanded. Vessel-resident BM-derived Sca-1(+) calcifying progenitor cells displayed nonhematopoietic, mesenchymal characteristics. To evaluate the modulation of in vivo calcification, we established models of ectopic and atherosclerotic calcification. Computed tomography indicated that Sca-1(+) progenitor cells increased the volume and calcium scores of ectopic calcification. However, Sca-1(+)/PDGFRα(-) cells treated with a PPARγ agonist decreased bone formation 2-fold compared with untreated cells. Systemic infusion of Sca-1(+)/PDGFRα(-) cells into Apoe(-/-) mice increased the severity of calcified atherosclerotic plaques. However, Sca-1(+)/PDGFRα(-) cells in which PPARγ was activated displayed markedly decreased plaque severity. Immunofluorescent staining indicated that Sca-1(+)/PDGFRα(-) cells mainly expressed osteocalcin; however, activation of PPARγ triggered receptor activator for nuclear factor-κB (RANK) expression, indicating their bidirectional fate in vivo. These findings suggest that a subtype of BM-derived and vessel-resident progenitor cells offer a therapeutic target for the prevention of vascular calcification and that PPARγ activation may be an option to reverse calcification.

BACKGROUND: Otologic manifestations are one of the most consistent findings of CHARGE syndrome found in more than 90%. Since genetic analysis of the CHD7 gene has rarely been performed in previous reports dealing with ear abnormalities, the genotypic spectrum of CHD7 mutations was analyzed in deaf patients with CHARGE syndrome, and the clinical considerations concerning auditory rehabilitation were investigated. METHODS: Nine Korean patients with CHARGE syndrome showing profound hearing loss and semicircular canal aplasia were included. All 38 exons of CHD7 were analyzed by direct sequencing. For splice site variations, in silico and exon-trapping analyses were performed to verify the pathogenicity of nucleotide variations. Clinical features and the outcome of auditory rehabilitation were also analyzed. RESULTS: Eight of 9 patients revealed alterations of the CHD7 gene including 3 frameshift, 2 nonsense, 2 splice site, and 1 missense mutations. Five of 9 patients were clinically diagnosed as atypical CHARGE syndrome but demonstrated various mutations of the CHD7 gene. One familial case showed intra-familial variability. Radiologic findings suggesting cochleovestibular nerve deficiency were identified in most of the patients. Of the 8 patients who underwent cochlear implantation, 5 patients demonstrated favorable outcome. Larger diameter of the cochleovestibular nerve on imaging and absence of severe mental retardation were factors related to better outcome after cochlear implantation rather than the type of CHD7 mutations. Auditory brainstem implantation was performed in two patients who did not benefit from cochlear implantation. CONCLUSIONS: Genetic analysis of the CHD7 gene should be performed in cases with semicircular canal aplasia even when other typical features of CHARGE syndrome are absent. For auditory rehabilitation in CHARGE syndrome, cochlear implantation should be strongly recommended in selected cases with favorable prognostic factors. Auditory brainstem implantation may be a viable option in patients with CHARGE syndrome who have failed to benefit from cochlear implantation.