A/J mice exhibit early-onset hearing loss linked to Cdh23, mitochondrial tRNA-Arg (mt-Tr), and citrate synthase (Cs) variants. Although developmental cochlear defects have been identified in juvenile A/J mice, the hierarchical contributions of mt-Tr versus Cs remain unclear. Using reciprocal intercross-derived strains to decouple mitochondrial haplotypes from nuclear factors, we demonstrate that the mitochondrial background is the primary determinant of auditory dysfunction. Mice with A/J mtDNA (AXB strains) displayed significantly higher ABR thresholds, accelerated hair cell attrition, and severe stereocilia dysmorphology compared to those with B6 mtDNA (BXA strains), occurring largely independently of the Cs genotype. While the Cs mutation exacerbated hearing loss, its impact was secondary to that of the dominant mitochondrial background. Systemic behavioral assessments and mitochondrial assays confirmed that A/J mitochondria exert a more profound metabolic impact than the Cs mutation. Our findings establish that the mitochondrial genomic background, with the mt-Tr locus as a prominent candidate variant, serves as the principal driver of developmental cochlear defects and early-onset hearing loss in A/J mice, while the nuclear Cs mutation acts as a synergistic modifier. This study underscores the critical role of mitonuclear crosstalk in inner ear maturation and provides new insights into the etiology of hereditary hearing loss.

Hearing loss and vestibular disorders represent major otologic disease challenges. Traditional disease models struggle to accurately mimic human otologic pathologies due to species differences and limited physiological relevance. Recent advancements in otic vitro models have provided crucial tools for related research. The core representatives include the middle ear epithelial cell model cultured at the air-liquid interface (ALI) and inner ear organoids. ALI culture of middle ear epithelial cells highly mimics middle ear tissue structure and function, finding applications in drug screening and toxicity assessment. Inner ear organoids facilitate the in vitro generation of functional three-dimensional structures containing hair cells, supporting cells, and neurons, while recapitulating both inner ear development and specific disease phenotypes. This review highlights the origins, research progress, and application prospects of these two model types, aiming to provide references for elucidating otologic disease mechanisms, personalized drug screening, and evaluating gene therapy strategies.

BACKGROUND:Acute otitis media (AOM) is highly prevalent among preschool children and can lead to chronic otitis media or severe complications if untreated. The pathogenesis of AOM is closely tied to the host's immune response, yet the expression profile of cytokines, which mediate these responses, remains poorly defined. PURPOSE:This study aims to identify cytokines involved in AOM immune responses and to elucidate their roles at different stages of the disease. METHODS:We induced AOM in mice by injecting nontypeable Haemophilus influenzae (NTHi) through the tympanic membrane. Middle ear tissues were collected for analysis. PCR Array and Protein Array identified cytokines at 6 and 12 hours (h) post-infection. qPCR and Luminex multiplex detection technology were then used to track cytokine expression at various key time points, allowing us to speculate on their roles in the immune process. RESULTS:PCR Array identified 13 cytokines with significant mRNA differences at 6 h. Protein Array identified 9 differentially expressed cytokines at 12 h qPCR tracked mRNA expression at key time points (6 h, 12 h, 1day (d), 2 d, 3 d and 7 d), revealing a total of 20 cytokines. Luminex detected 31 cytokines at key time points (12 h 1 d, 2 d and 5 d), 10 of which were previously mentioned. Cytokines were classified into three distinct categories according to their expression trends: early-phase (n = 13), progressive-phase (n = 20), and terminal-phase (n = 4) cytokines. CONCLUSION:Cytokines play distinct and crucial roles at each stage of AOM, with potential interactions among those highly expressed in the same stage.

Age-related hearing loss (ARHL) is a gradual, symmetrical sensorineural disorder. Exploring the pathogenesis of ARHL from a biological perspective is important for its treatment. In this study, we analyzed the circRNA expression profiles of 2-month-old miR-29a+/+ mice and miR-29a-/- mice by transcriptome sequencing to investigate the role of circRNAs in ARHL. We identified 12 differentially expressed circRNAs in the two groups. Our focus was on circRNAs predicted to regulate miR-29a, with novel_circ_0004013 identified as having a targeted binding relationship with miR-29a-3p. Dual luciferase assays confirmed that miR-29a-3p is a direct target of novel_circ_0004013. Fluorescence in situ hybridization (FISH) was employed to localize the novel_circ_0004013 in HEI-OC1 cells and the cochlea. Novel_circ_0004013 was mainly expressed in the cytoplasm. In the hair cells (HCs) and stria vascularis (SV) regions of miR-29a-/- mice, novel_circ_0004013 expression was higher than the corresponding regions in miR-29a+/+ mice. Furthermore, Western blot assays revealed that levels of oxidative stress and apoptosis were significantly decreased in HEI-OC1 cells following the knockdown of novel_circ_0004013, whereas these levels were significantly increased in HEI-OC1 cells after the knockdown of miR-29a-3p. It was indicated in rescue assays that novel_circ_0004013 expedited oxidative stress and apoptosis of HEI-OC1 cells via modulation on miR-29a-3p. These findings may reveal the important role of novel_circ_0004013 in hearing loss and provide a new perspective and theoretical basis for the molecular mechanism of ARHL.

Rational:Asthma severity assessment is essential for asthma management. Transcriptomics contributes substantially to asthma pathogenesis. Then, this study aimed to explore asthma severity-associated transcriptomics profile and promising biomarkers for asthma severity prediction. Methods:In discovery cohort, induced sputum cells from 3 non-severe and 3 severe asthma patients were collected and analyzed using RNA-seq. Multivariate analysis was performed to explore asthma severity-associated transcriptomics profile and differential expressed genes (DEGs). The Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) were used for pathway enrichment analysis. Subsequently, based on the previous study and clinical experience, the mRNA expressions of 6 overlapped asthma severity-associated DEGs and C3 in induced sputum cells and serum C3 were verified in validation cohort. Results:Distinct asthma severity-associated transcriptomics profile was identified in induced sputum cells in discovery cohort. Then, 345 DEGs were found, of which 38 terms and 32 pathways were enriched using GO and KEGG, respectively. In validation cohort, the mRNA expressions of ZNF331, CD163, MACC1, ADAMTS2, and C3 were increased, and RYR1 and NRXN3 were decreased in induced sputum cells in severe asthma. Meanwhile, the AUC of ROC was 0.890 for serum C3 in asthma severity prediction, with the best cut-off of 1.272 g/L. Conclusion:Collectively, this study provides the first identification of the association between induced sputum cells transcriptomics profile and asthma severity, indicating the potential value of transcriptomics for asthma management. The study also reveals the promising value of serum C3 for predicting asthma severity in clinical practice.

Noise-induced hearing loss (NIHL) is a common auditory disorder driven by calcium overload, oxidative stress, and apoptosis in cochlear sensory hair cells. The transient receptor potential canonical 6 (TRPC6), a nonselective cation channel that can be activated by norepinephrine, is implicated in calcium influx and associated cellular damage. This study explores the protective effects of clonidine, an FDA-approved α2-adrenergic receptor agonist that reduces sympathetic nervous system activity and norepinephrine release, on NIHL in mice. Clonidine treatment significantly preserved hearing thresholds, reduced damage to outer hair cells and ribbon synapses, and suppressed TRPC6 channel activation induced by noise exposure. Mechanistically, clonidine alleviated calcium influx, inhibited the calcium-dependent MLCK-MRLC signaling pathway, and attenuated oxidative stress and apoptosis in cochlear hair cells. Molecular docking analyses demonstrated strong binding between norepinephrine and TRPC6, elucidating the regulatory role of clonidine in calcium signaling. These findings highlight clonidine's potential to prevent NIHL by maintaining intracellular calcium homeostasis and reducing cochlear damage via the modulation of norepinephrine and TRPC6 activity. TRPC6 emerges as a promising therapeutic target for preventing and managing noise-induced auditory dysfunction.

Vestibular dysfunction (VD) is increasingly acknowledged as a significant contributor to falls and deterioration in health. Cadherin 23 (Cdh23) serves as an essential protein responsible for facilitating the mechanical transduction processes in hair cells, and variations in this gene have been recognized as possible factor to auditory impairments and VD. The gene Cdh23 encodes glycoproteins that play a role in cell adhesion and are crucial for the development of stereocilia bundles. In this research, we generated CDH23 functional null mice (Cdh23V2J2/V2J2). Here, our findings indicated that Cdh23V2J2/V2J2 mice exhibited weakened balance and coordination abilities, characterized by rotation and head nodding movements. The development of stereocilia and otoliths was abnormal in these mice. Scanning electron microscopy (SEM) analysis revealed abnormal changes in the arrangement and length of stereocilia bundles in Cdh23V2J2/V2J2 mice compared to wild-type mice. The abnormal alterations of otolith shape in Cdh23V2J2/V2J2 mice also were observed, which was smaller in saccules but larger in utricles. Furthermore, we also observed that the number of vestibular hair cells (VHCs) decreased in Cdh23V2J2/V2J2 mice, along with significant activation of the p53 and FoxO signaling pathways at postnatal day 56 (P56). This study elucidates potential mechanisms, histopathological features, and resultant genomic alterations associated with VD in Cdh23V2J2/V2J2 mice, thereby establishing a scientific foundation for prospective vestibular rehabilitative interventions.

Polystyrene nanoplastics are a novel class of pollutants. They are easily absorbed by living organisms, and their potential toxicity has raised concerns. However, the impact of polystyrene nanoplastics on auditory organs remains unknown. Here, our results showed that polystyrene nanoplastics entered the cochlea of mice, HEI-OC1 cells, and lateral line hair cells of zebrafish, causing cellular injury and increasing apoptosis. Additionally, we found that exposure to polystyrene nanoplastics resulted in a significant elevation in the auditory brainstem response thresholds, a loss of auditory sensory hair cells, stereocilia degeneration and a decrease in expression of Claudin-5 and Occludin proteins at the blood-lymphatic barrier in mice. We also observed a significant decrease in the acoustic alarm response of zebrafish after exposure to polystyrene nanoplastics. Mechanistic analysis revealed that polystyrene nanoplastics induced up-regulation of the Nrf2/HO-1 pathway, increased levels of malondialdehyde, and decreased superoxide dismutase and catalase levels in cochlea and HEI-OC1 cells. Furthermore, we observed that the expression of ferroptosis-related indicators GPX4 and SLC7A11 decreased as well as increased expression of ACLS4 in cochlea and HEI-OC1 cells. This study also revealed that polystyrene nanoplastics exposure led to increased expression of the inflammatory factors TNF-α, IL-1β and COX2 in cochlea and HEI-OC1 cells. Further research found that the cell apoptosis, ferroptosis and inflammatory reactions induced by polystyrene nanoplastics in HEI-OC1 cells was reversed through the pretreatment with N-acetylcysteine, a reactive oxygen species inhibitor. Overall, our study first discovered and systematically revealed the ototoxicity of polystyrene nanoplastics and its underlying mechanism.

Craniofacial dysmorphism, skeletal anomalies, and impaired intellectual development syndrome (CFSMR1; Online Inheritance in Man number 213980) is characterized by craniofacial dysmorphism, skeletal anomalies, and mental retardation. However, reports of hearing issues have been limited. To investigate hearing-related aspects of CFSMR1, Tmco1 knockout mice (Tmco1-/-) exhibiting similar symptoms to human patients were used in this study. Otitis media (OM) was discovered in approximately 80% of Tmco1-/- mice, which led to moderate conductive hearing loss at 3 months old and further progressed to deafness 2 months later. Pathology studies of Tmco1-/- mice revealed a thickened middle ear (ME) epithelium and pronounced inflammatory infiltrates in the ME cavity and Eustachian tube of Tmco1-/- OM mice. Micro-computed tomography scan of 5-month-old Tmco1-/- OM mice showed significantly reduced ME volume and ME malformation. Tartrate-resistant acid phosphatase and Runt-related transcription factor 2, receptor activator of NF-κB ligand expression in ME revealed increased osteoclast activity and significantly decreased bone formation, suggesting potential causes of ME malformation. This study represents the first report of the audiological characteristics and the elucidation of potential mechanisms in Tmco1-/- mice. It enriches our understanding of the phenotypes associated with CFSMR1 in the field of otology and provides a promising model for chronic OM with conductive hearing loss.

BACKGROUND:A/J mice exhibited a severe hearing loss (HL) at juvenile stage. Up-to-date, studies on HL in A/J mice have mostly focused on the damage or dysfunction of hair cells (HCs), spiral ganglion neurons (SGNs), and stereocilia. We examined A/J mice at the early postnatal stage and found that the damage and the loss of outer hair cells (OHCs) are not severe enough to explain the profound HL observed at this age, which suggests that other cochlear defects may be responsible for HL. To better understand the mechanisms of early-onset HLin A/J mice, we characterized the pathology of the cochlea from postnatal day 3 to day 21. RESULTS:Our results showed defects in cochlear HC stereocilia and MET channel function as early as 3 days old. We also found abnormal localization and a significant reduction in the number of ribbon synapses in 2-week-old A/J mice. There are also abnormalities in the cochlear nerve innervation and terminal swellings in 3-week-old A/J mice. CONCLUSION:All of the abnormalities of cochlear existed in the A/J mice were identified in the juvenile stage and occurred before HCs or auditory nerve loss and was the initial pathological change. Our results suggest that developmental defects and subsequent cochlear degeneration are responsible for early-onset hearing loss in A/J mice.

Hemorrhagic shock (HS) is a critical condition with high mortality caused by acute blood loss. Cardiac injury and dysfunction induced by HS is a major factor associated with the poor prognosis of affected patients. Schisandrin A (Sch A), a dibenzocyclooctadiene lignan extracted from Fructus schisandrae, exhibits multiple biological activities, including anti-inflammatory, and antioxidant effects. However, the effect of Sch A on HS-caused cardiac injury and its underlying mechanism still lack research. In this study, we established an HS rat model through blood loss from the femoral artery and monitoring mean arterial pressure (MAP) followed by fluid resuscitation. Our findings suggested that cardiac dysfunction and pathological injury were induced by HS and attenuated by Sch A treatment in a dose-dependent manner. Apoptosis in cardiac tissue was promoted by HS, but suppressed after administration of Sch A by decreasing the protein expressions of cleaved-caspase-3 and -9. Moreover, excessive ROS production induced by HS was mitigated by Sch A, and the levels of oxidative stress indicators were improved by Sch A. Additionally, HS triggered the reduction of mitochondrial membrane potential (MMP), and led to mitochondrial dysfunction. Sch A reversed this effect of HS on mitochondria. The transformation of cytochrome c (Cyto c) induced by HS was also restored by Sch A. Importantly, the activation of the Nrf2 signaling pathway mediated the protective effects of Sch A against cardiac injury induced by HS. In conclusion, it was found that Sch A ameliorated HS-induced cardiac injury and dysfunction through suppressing apoptosis and oxidative stress, as well as alleviating mitochondrial dysfunction via the Nrf2 signaling pathway.

Input analysis of corresponding Co-IP.

The synergistic effect between metformin and ABT-263 is independent of the cell cycle changes and metformin sensitizes ABT-263 not via changing the levels of BCL-2, BCL-XL, cIAP1 and cIAP2.

Age-related hearing loss (ARHL) is the most common sensory degenerative disease and can significantly impact the quality of life in elderly people. A previous study using GeneChip miRNA microarray assays showed that the expression of miR-29a changes with age, however, its role in hearing loss is still unclear. In this study, we characterized the cochlear phenotype of miR-29a knockout (miR-29a–/–) mice and found that miR-29a-deficient mice had a rapid progressive elevation of the hearing threshold from 2 to 5 months of age compared with littermate controls as measured by the auditory brainstem response. Stereocilia degeneration, hair cell loss and abnormal stria vascularis (SV) were observed in miR-29a–/– mice at 4 months of age. Transcriptome sequencing results showed elevated extracellular matrix (ECM) gene expression in miR-29a–/– mice. Both Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that the key differences were closely related to ECM. Further examination with a transmission electron microscope showed thickening of the basilar membrane in the cochlea of miR-29a–/– mice. Five Col4a genes (Col4a1-a5) and two laminin genes (Lamb2 and Lamc1) were validated as miR-29a direct targets by dual luciferase assays and miR-29a inhibition assays with a miR-29a inhibitor. Consistent with the target gene validation results, the expression of these genes was significantly increased in the cochlea of miR-29a–/– mice, as shown by RT-PCR and Western blot. These findings suggest that miR-29a plays an important role in maintaining cochlear structure and function by regulating the expression of collagen and laminin and that the disturbance of its expression could be a cause of progressive hearing loss.

The influence of the cotreatment with metformin and ABT-263 on different translation-relevant kinase signaling pathways.

Combination of metformin with ABT-263 had no significant growth inhibition effect on HEK-293 cells.

Metformin attenuates ABT-263-induced MCL-1, XIAP and SURVIVIN through neither transcriptional nor posttranslational regulation.

Metformin and ABT-263 synergistically inhibit the growth of p53-defective (but not p53-WT) cancer cells and the metformin/ABT-263 combination more effectively elicits apoptosis in p53-defective xenograft tumors compared to p53-WT xenograft tumors.

Aims: Age-related hearing loss (ARHL) is a significant health concern, and DBA/2J (D2) and C57BL/6 (B6) mouse strains serve as valuable models for its study. B6 mice, harboring a homozygous ahl allele in Cdh23, manifest high-frequency hearing loss at 3 months. In contrast, D2 mice, carrying the R109H variant of the Fascin-2 gene (Fscn2), experience early-onset hearing loss by 3 weeks. Yet, the underlying molecular mechanisms driving early -onset hearing loss in D2 mice remain elusive. This study aimed to identify novel genes and regulatory pathways as therapeutic targets for early deafness. Main methods: This study employs RNA-sequencing (RNA-seq) to analyze cochlear mRNA expression at two different ages in D2 and B6 mice, respectively. The differentially expressed genes (DEGs) are uniquely associated with D2 mice by Venn diagram analysis. A protein-protein interaction (PPI) network is further constructed, followed by module analysis utilizing MCODE. Enrichment analysis of GO and KEGG pathways revealed bio-logical functions and molecular pathways. The PPI network and VarElect analysis are conducted for genes within these pathways, facilitating the identification of pivotal genes based on scoring criteria. Subsequently, five genes are meticulously selected and validated through qRT-PCR.Key findings: Notably, 1181 DEGs are uniquely associated with D2 mice by Venn diagram analysis. GO and KEGG pathway enrichment analyses shed light on distinctive pathways in D2 mice, encompassing DNA replication, mismatch repair, base excision repair, and nucleotide excision repair, which are associated with apoptosis. Five genes involved in these pathways were finally selected and validated by qRT-PCR. Their down-regulation with age is consistent with RNA-seq result.Significance: Our study underscores the potential implication of down-regulated genes associated with DNA replication and DNA damage repair in the early-onset hearing loss observed in D2 mice.

Age-related hearing loss (ARHL) is a common neurodegenerative disease. Its molecular mechanisms have not been fully elucidated. In the present study, we obtained differential mRNA expression in the cochlea of 2-month-old miR-29a+/+ mice and miR-29a-/- mice by RNA-seq. Gene ontology (GO) analysis was used to identify molecular functions associated with hearing in miR-29a-/- mice, including being actin binding (GO: 0003779) and immune processes. We focused on the intersection of differential genes, miR-29a target genes and the sensory perception of sound (GO:0007605) genes, with six mRNA at this intersection, and we selected Col1a1 as our target gene. We validated Col1a1 as the direct target of miR-29a by molecular and cellular experiments. Total 6 pathways involved in Col1a1 were identified by through Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. We selected the focal adhesion pathway as our target pathway based. Their expression levels in miR-29a-/- mice were verified by qRT-PCR and Western blot. Compared with miR-29a+/+ mice, the expression levels of Col1a1, Itga4, Itga2, Itgb3, Itgb7, Pik3r3 and Ptk2 were different in miR-29a-/- mice. Immunofluorescence was used to locate genes in the cochlea. Col1a1, Itga4 and Itgb3 were differentially expressed in the basilar membranes and stria vascularis and spiral ganglion neurons compared to miR-29a+/+ mice. Pik3r3 and Ptk2 were differentially expressed in the basilar membranes and stria vascularis, but not at the s spiral ganglion neurons compared to miR-29a+/+ mice. Our results show that when miR-29a is knocked out, the Col1a1 mediates the focal adhesion pathway may affect the hearing of miR-29a-/- mice. These findings may provide a new direction for effective treatment of age-related hearing loss.