OBJECTIVES: Neurodegenerative diseases are closely associated with myelin loss, and the proliferation and differentiation of oligodendrocyte precursor cells (OPCs) are crucial to remyelination. However, the regulatory mechanisms involved remain incompletely understood. This study aims to investigate how astrocytes (ASTs) regulate the secretion of chitinase-3-like protein 1 (CHI3L1) via connexin 47 (Cx47)-mediated exosome signaling, and its subsequent effect on OPC proliferation. METHODS: Primary cells were isolated from postnatal day 1 Sprague-Dawley (P1SD) rats to establish 3 culture conditions: OPCs alone (Group O), OPCs in direct contact with ASTs (Group C), and OPCs cultured with AST-conditioned medium (Group A). Cellular morphology and proliferation were assessed using optical microscopy, 5-ethynyl-2'- deoxyuridine (EdU) incorporation, and flow cytometry. RNA sequencing (RNA-Seq) and bioinformatics analysis (BA) were conducted to identify differentially expressed genes (DEGs) among groups. Protein expression and cell cycle distribution were analyzed by Western blotting (WB) and flow cytometry. Exosomes were isolated and purified via differential centrifugation, characterized by nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM), and CHI3L1 expression in exosomes was verified via WB. Cx47 was silenced using small interfering RNA (siRNA) to evaluate its effect on OPC proliferation and exosome secretion. Artificial exosomes were constructed by encapsulating CHI3L1 in single unilamellar vesicles (SUVs), whose structure and size were validated by NTA and TEM. Following Cx47 knockdown, artificial exosomes were added back, and OPC proliferation was assessed via flow cytometry and EdU assay. RESULTS: Direct co-cultured with ASTs (Group C) resulted in significantly enhanced OPC proliferation compared to the Group O and Group A (P<0.05). RNA-Seq and WB analyses revealed that ASTs promote OPC proliferation and exosome secretion enriched in CHI3L1 through Cx47. Cx47 knockdown by siRNA led to significant decreases in OPC proliferation and exosome release (P<0.05). The inhibitory effect of Cx47 silencing on OPC proliferation was partially reversed by supplementation with either isolated exosomes or exogenous CHI3L1. CONCLUSIONS This study reveals a novel mechanism by which ASTs regulate OPC proliferation: Through direct contact, ASTs enhance the secretion of CHI3L1-rich exosomes via Cx47, thereby converting intercellular contact signals into secretory signals that promote OPC proliferation. As a key exosomal molecule, CHI3L1 may play an important role in neural function and remyelination and warrants further investigation.
Animals ; Exosomes/metabolism* ; Cell Proliferation ; Rats, Sprague-Dawley ; Rats ; Connexins/genetics* ; Oligodendrocyte Precursor Cells/metabolism* ; Astrocytes/metabolism* ; Chitinase-3-Like Protein 1/metabolism* ; Cells, Cultured ; Cell Differentiation

Objective:To explore the trend of hearing changes in infants with GJB2 gene p.V37I mutation at different months. Methods:The subjects were 54 children（108 ears） with p.V37I homozygous or compound heterozygous mutation in GJB2 gene. All the subjects underwent auditory brainstem response, auditory steady-state response, acoustic immittance and other audiological tests. Children were divided into three groups according to their age, 26 cases in group A were ≤3 months old, 17 cases in group B were>3~≤6 months old, and 11 cases in group C were>6 months old. Statistical analysis was performed on the three groups of ABR response threshold, hearing degree, the ASSR average response threshold of four frequencies and the ASSR response thresholds for each frequency of 500, 1 000, 2 000 and 4 000 Hz. Results:Among the 54 cases, 35 were male and 19 were female, with an age rang of 2-27 months and a median age of 4 months. The ABR response threshold of the three groups were ranked from low to high as group A, group B and group C, and the difference was statistically significant（P<0.05）. The ABR response thresholds of the three groups were ranked from low to high as group A, group B, and group C. The comparison between groups showed that the ABR response thresholds of group C was higher than that of group A（P=0.006）. The proportion of confirmed hearing loss in the three groups was 34.61%, 50.00% and 63.64%, respectively, and the difference of hearing level among the three groups was statistically significant（P<0.05）. The comparison between groups showed that the difference between group A and group C was statistically significant（P=0.012）, normal hearing accounted for the highest proportion in group A（65.39%）, while mild hearing loss accounted for the highest proportion in group C（45.46%）. The ASSR average response thresholds of the four frequencies in the three groups were ranked from low to high as group A, group B and group C, and the difference is statistically significant（P<0.05）. The comparison between groups showed that response ASSR thresholds of group C was higher than that of group A（P=0.002）. Response thresholds of ASSR in each frequency in the three groups were all ranked from low to high as in group A, group B and group C, and the differences were statistically significant（P<0.05）. Compared with each other between groups, response ASSR thresholds of group C was higher than those of group A（P=0.003） and group B（P=0.015） at 500 Hz, while response ASSR thresholds of group C was higher than group A at 1 000 Hz（P=0.010） and 2 000 Hz（P<0.001）, and there was no statistical difference at 4 000 Hz. Conclusion:The incidence of hearing loss in GJB2 gene p.V37I mutation increased with age, and the degree of hearing loss increased, the hearing progression was mainly 500, 1 000 and 2 000 Hz suggesting regular follow-up and alert to hearing changes.
Humans ; Connexin 26 ; Male ; Female ; Infant ; Child, Preschool ; Mutation ; Evoked Potentials, Auditory, Brain Stem ; Connexins/genetics* ; Auditory Threshold ; Hearing/genetics* ; Hearing Loss/genetics*

Objective:To investigate the detection of the age and pathway and the etiology of sensorineural hearing loss in children, and to guide the early diagnosis. Methods:A retrospective analysis was conducted on the children who passed neonatal hearing screening but were diagnosed with sensorineural hearing loss in our department from January 2019 to September 2022. The clinical characteristics of 66 children with complete medical history, audiology examination, imaging examination and genetic detection of hearing loss were studied. The age group, detection route and degree of hearing loss were analyzed statistically. Results:①The children were aged from 7 months to 12 years old, and most of them were over 3 years old. ②The ways of detection were as follows: 23 cases（34.85%） due to abnormal hearing, 21 cases（31.82%） due to poor language, 15 cases（22.73%） found during physical examination, and 7 cases（10.61%） found with otitis media. Physical examination findings were concentrated in children aged ≤1 year old or 3-6 years old. ③Among the 56 cases, the degree of binaural hearing loss ranged from mild to severe, and most of those within 3 years of age had severe or above hearing loss. There were statistically significant differences in the degree of hearing loss distribution among different detection approaches（P<0.001）. Most children with hearing or language problems had moderate to severe or above hearing loss, and the proportion was significantly higher than that of children detected during physical examination or otitis media. ④There were 21 cases（31.82%） with a pathogenic mutation of GJB2 gene and 9 cases（13.64%） of large vestibular aqueduct syndrome, 7 of which were related to SLC26A4 gene mutation. There were 8 cases（12.12%） with high risk factors of hearing loss. There was 1 case（1.52%） with progressive speech loss after severe infection and high fever and 1 case（1.52%） with unilateral cochlear nerve dysplasia. Conclusion:Delayed hearing loss can occur at all ages and was not easy to be detected in time. The etiology was related to the mutation of deafness-related genes and the high risk factors of hearing loss. Combining hearing and gene screening in childhood, guiding parents to observe children's hearing response and language development, especially strengthening the follow-up of children with high risk factors for hearing loss, is conducive to the early diagnosis of delayed hearing loss.
Humans ; Hearing Loss, Sensorineural/genetics* ; Retrospective Studies ; Child ; Child, Preschool ; Infant ; Connexin 26 ; Male ; Female ; Connexins/genetics* ; Mutation ; Sulfate Transporters ; Hearing Tests

Hearing loss is the most prevalent disabling disease. Cochlear implantation（CI） serves as the primary intervention for severe to profound hearing loss. This consensus systematically explores the value of genetic diagnosis in the pre-operative assessment and efficacy prognosis for CI. Drawing upon domestic and international research and clinical experience, it proposes an evidence-based medicine three-tiered prognostic classification system（Favorable, Marginal, Poor）. The consensus focuses on common hereditary non-syndromic hearing loss（such as that caused by mutations in genes like GJB2, SLC26A4, OTOF, LOXHD1） and syndromic hereditary hearing loss（such as Jervell & Lange-Nielsen syndrome and Waardenburg syndrome）, which are closely associated with congenital hearing loss, analyzing the impact of their pathological mechanisms on CI outcomes. The consensus provides recommendations based on multiple round of expert discussion and voting. It emphasizes that genetic diagnosis can optimize patient selection, predict prognosis, guide post-operative rehabilitation, offer stratified management strategies for patients with different genotypes, and advance the application of precision medicine in the field of CI.
Humans ; Cochlear Implantation ; Prognosis ; Hearing Loss/surgery* ; Consensus ; Connexin 26 ; Mutation ; Sulfate Transporters ; Connexins/genetics*

Objective:To analyze genetic factors and phenotype characteristics in pediatric population with slight-to-moderate sensorineural hearing loss. Methods:Children with slight-to-moderate sensorineural hearing loss of and their parents, enrolled from the Chinese Deafness Genome Project, were studied. Hearing levels were assessed using pure tone audiometry, behavioral audiometry, auditory steady state response（ASSR）, auditory brainstem response（ABR） thresholds, and deformed partial otoacoustic emission（DPOAE）. Classification of hearing loss is according to the 2022 American College of Medical Genetics and Genomics（ACMG） Clinical Practice Guidelines for Hearing Loss. Whole exome sequencing（WES） and deafness gene Panel testing were performed on peripheral venous blood from probands and validations were performed on their parents by Sanger sequencing. Results:All 134 patients had childhood onset, exhibiting bilateral symmetrical slight-to-moderate sensorineural hearing loss, as indicated by audiological examinations. Of the 134 patients, 29（21.6%） had a family history of hearing loss, and the rest were sporadic patients. Genetic causative genes were identified in 66（49.3%） patients. A total of 11 causative genes were detected, of which GJB2 was causative in 34 cases（51.5%）, STRC in 10 cases（15.1%）, MPZL2 gene in six cases（9.1%）, and USH2A in five cases（7.6%）.The most common gene detected in slight-to-moderate hearing loss was GJB2, with c. 109G>A homozygous mutation found in 16 cases（47.1%） and c. 109G>A compound heterozygous mutation in 9 cases（26.5%）. Conclusion:This study provides a crucial genetic theory reference for early screening and detection of mild to moderate hearing loss in children, highlighting the predominance of recessive inheritance and the significance of gene like GJB2, STRC, MPZL2, USH2A.
Humans ; Child ; Connexins/genetics* ; Connexin 26/genetics* ; Hearing Loss, Sensorineural/diagnosis* ; Mutation ; Usher Syndromes ; Hearing Loss, Bilateral ; Audiometry, Pure-Tone ; Intercellular Signaling Peptides and Proteins

Objective:To elucidate the correlation between the GJB2 gene and auditory neuropathy, aiming to provide valuable insights for genetic counseling of affected individuals and their families. Methods:The general information, audiological data（including pure tone audiometry, distorted otoacoustic emission, auditory brainstem response, electrocochlography）, imaging data and genetic test data of 117 auditory neuropathy patients, and the patients with GJB2 gene mutation were screened out for the correlation analysis of auditory neuropathy. Results:Total of 16 patients were found to have GJB2 gene mutations, all of which were pathogenic or likely pathogenic.was Among them, one patient had compound heterozygous variants GJB2[c. 427C>T][c. 358_360del], exhibiting total deafness. One was GJB2[c. 299_300delAT][c. 35_36insG]compound heterozygous variants, the audiological findings were severe hearing loss.The remaining 14 patients with GJB2 gene variants exhibited typical auditory neuropathy. Conclusion:In this study, the relationship between GJB2 gene and auditory neuropathy was preliminarily analyzed,and explained the possible pathogenic mechanism of GJB2 gene variants that may be related to auditory neuropathy.
Humans ; Connexins/genetics* ; Connexin 26/genetics* ; Hearing Loss, Central/genetics* ; Deafness/genetics* ; Mutation

Objective:By conducting genetic testing of hereditary hearing loss in pregnant women within 17 weeks of gestation in Dali areas, the importance of genetic testing and genetic counseling during pregnancy was emphasized. Methods:Twenty-one mutation sites of 4 hearing loss genes, including GJB2, GJB3, SLC26A4 and mtDNA, were detected by PCR amplification technology. The positive ratio, mutation ratio and ethnic distribution of positive samples were statistically described. Results:The positive ratios of GJB2 and SLC26A4 genes were 1.24% and 1.43%, respectively, with mutation rates of 40.62% and 46.88% in the positive samples, respectively. The positive ratio of GJB3gene was 0.19%, and mtDNA mutation genes accounted for 0.14%, and all of them were mtDNA（Heterozygous）. There was only one case of GJB2/SLC26A4 double positive multi-gene mutation, with a positive ratio of 0.05%. The frequency of GJB2 c. 235delC site was the highest, accounting for 65.38% of GJB2 mutation genes and 26.56% of mutation gene samples. Conclusion:GJB2 and SLC26A4 are the most common genes of hearing loss, and GJB2 c. 235delC site is the most common mutation site. Identifying the hearing loss mutation site is of great importance to prevent the birth of hereditary hearing loss children, and genetic diagnosis, genetic counseling, and appropriate intervention are crucial to alleviate congenital problems.
Humans ; Female ; Pregnancy ; Sulfate Transporters/genetics* ; Connexin 26 ; Genetic Testing/methods* ; Connexins/genetics* ; Mutation ; Hearing Loss/diagnosis* ; DNA, Mitochondrial/genetics* ; Adult ; Membrane Transport Proteins/genetics* ; Genetic Counseling

Objective:To analyze the hearing phenotypes of p. V37I homozygote and compound heterozygote mutation in GJB2 gene, and to provide basis for genetic counseling. Methods:Fifty-three subjects with p. V37I homozygote and compound heterozygote mutation were recruited at Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital from January 2023 to March 2024. All subjects received universal newborn hearing screening（UNHS）, 23-site chip neonatal deafness genetic screening and audiological tests, including ABR, acoustic immittance, DPOAE, ASSR. The results of newborn hearing screening and hearing diagnosis were compared between homozygous mutation group of 30 cases and compound heterozygous mutation group of 23 cases. Results:In 53 cases, the overall refer rate of UNHS was 64.15%（34/53）, the refer rate of homozygous mutation group was 80.00%（24/30）, which was higher than that of compound heterozygous mutation group（43.48%, 10/23）, the difference between the two groups was statistically significant（P<0.05）. Three subjects with p. V37I compound heterozygous mutation had passed UNHS and diagnosed with unilateral mild hearing loss. The average age of diagnosis of 53 cases was （3.77±1.40） months, 25 cases with hearing loss accounted for 47.17%, including 13 cases with unilateral, 12 cases with bilateral, 28 cases with normal hearing accounted for 52.83%. There was no significant difference between homozygous mutation group（56.67%, 17/30） and compound heterozygous mutation group（34.78%, 8/23） in the proportion of confirmed hearing loss（P>0.05）. Among 37 ears of 25 patients with hearing loss, the proportion of mild, moderate and profound hearing loss were 70.27%（26/37）, 27.03%（10/37） and 2.70%（1/37）, respectively. The hearing loss degree of the homozygous mutation group and the compound heterozygous mutation group were mainly mild, accounting for 70.37%（19/27） and 70.00%（7/10） respectively. There was no significant difference between the two groups in the distribution of hearing loss degree（P>0.05）. Conclusion:The probability of hearing loss was 47.17% in infants of GJB2 gene p. V37I homozygote and compound heterozygote mutation, mainly mild hearing loss. There was no difference in the probability of hearing loss and the distribution of hearing loss degree between the two groups. Patients with p. V37I homozygous and compound heterozygous mutation currently diagnosed as normal hearing need continuous clinical follow-up.
Humans ; Connexin 26 ; Heterozygote ; Homozygote ; Female ; Phenotype ; Male ; Mutation ; Connexins/genetics* ; Infant ; Infant, Newborn ; Hearing Tests ; Neonatal Screening ; Deafness/genetics* ; Genetic Testing

OBJECTIVE: To assess the value of genetic screening by high-throughput sequencing (HTS) for the early diagnosis of neonatal diseases. METHODS: A total of 2 060 neonates born at Ningbo Women and Children's Hospital from March to September 2021 were selected as the study subjects. All neonates had undergone conventional tandem mass spectrometry metabolite analysis and fluorescent immunoassay analysis. HTS was carried out to detect the definite pathogenic variant sites with high-frequency of 135 disease-related genes. Candidate variants were verified by Sanger sequencing or multiplex ligation-dependent probe amplification (MLPA). RESULTS: Among the 2 060 newborns, 31 were diagnosed with genetic diseases, 557 were found to be carriers, and 1 472 were negative. Among the 31 neonates, 5 had G6PD, 19 had hereditary non-syndromic deafness due to variants of GJB2, GJB3 and MT-RNR1 genes, 2 had PAH gene variants, 1 had GAA gene variants, 1 had SMN1 gene variants, 2 had MTTL1 gene variants, and 1 had GH1 gene variants. Clinically, 1 child had Spinal muscular atrophy (SMA), 1 had Glycogen storage disease II, 2 had congenital deafness, and 5 had G6PD deficiency. One mother was diagnosed with SMA. No patient was detected by conventional tandem mass spectrometry. Conventional fluorescence immunoassay had revealed 5 cases of G6PD deficiency (all positive by genetic screening) and 2 cases of hypothyroidism (identified as carriers). The most common variants identified in this region have involved DUOX2 (3.93%), ATP7B (2.48%), SLC26A4 (2.38%), GJB2 (2.33%), PAH (2.09%) and SLC22A5 genes (2.09%). CONCLUSION Neonatal genetic screening has a wide range of detection and high detection rate, which can significantly improve the efficacy of newborn screening when combined with conventional screening and facilitate secondary prevention for the affected children, diagnosis of family members and genetic counseling for the carriers.
Child ; Infant, Newborn ; Humans ; Female ; Prospective Studies ; Connexins/genetics* ; Connexin 26/genetics* ; Glucosephosphate Dehydrogenase Deficiency ; Mutation ; Sulfate Transporters/genetics* ; DNA Mutational Analysis ; Genetic Testing/methods* ; Deafness/genetics* ; Neonatal Screening/methods* ; Hearing Loss, Sensorineural/genetics* ; High-Throughput Nucleotide Sequencing ; Solute Carrier Family 22 Member 5/genetics*

OBJECTIVE: To analyze the clinical significance of combined newborn hearing and deafness gene screening in Yuncheng area of Shanxi Province. METHODS: Results of audiological examinations, including transient evoked otoacoustic emission and automatic discriminative auditory brainstem evoked potentials, for 6 723 newborns born in Yuncheng area from January 1, 2021 to December 31, 2021, were retrospectively analyzed. Those who failed one of the tests were considered to have failed the examination. A deafness-related gene testing kit was used to detect 15 hot spot variants of common deafness-associated genes in China including GJB2, SLC26A4, GJB3, and mtDNA12S rRNA. Neonates who had passed the audiological examinations and those who had not were compared using a chi-square test. RESULTS: Among the 6 723 neonates, 363 (5.40%) were found to carry variants. These have included 166 cases (2.47%) with GJB2 gene variants, 136 cases (2.03%) with SLC26A4 gene variants, 26 cases (0.39%) with mitochondrial 12S rRNA gene variants, and 33 cases (0.49%) with GJB3 gene variants. Among the 6 723 neonates, 267 had failed initial hearing screening, among which 244 had accepted a re-examination, for which 14 cases (5.73%) had failed again. This has yielded an approximate prevalence of hearing disorder of 0.21% (14/6 723). Among 230 newborns who had passed the re-examination, 10 (4.34%) were found to have carried a variant. By contrast, 4 out of the 14 neonates (28.57%) who had failed the re-examination had carried a variant, and there was a significant difference between the two groups (P < 0.05). CONCLUSION Genetic screening can provide an effective supplement to newborn hearing screening, and the combined screening can provide a best model for the prevention of hearing loss, which can enable early detection of deafness risks, targeted prevention measures, and genetic counseling to provide accurate prognosis for the newborns.
Infant, Newborn ; Humans ; Connexins/genetics* ; Retrospective Studies ; Deafness/genetics* ; Connexin 26/genetics* ; Neonatal Screening/methods* ; Mutation ; Genetic Testing/methods* ; China/epidemiology* ; Hearing ; DNA Mutational Analysis