Potential role of modulating autophagy levels in sensorineural hearing loss.

In recent years, extensive research has been conducted on the pathogenesis of sensorineural hearing loss (SNHL). Apoptosis and necrosis have been identified to play important roles in hearing loss, but they cannot account for all hearing loss. Autophagy, a cellular process responsible for cell self-degradation and reutilization, has emerged as a significant factor contributing to hearing loss, particularly in cases of autophagy deficiency. Autophagy plays a crucial role in maintaining cell health by exerting cytoprotective and metabolically homeostatic effects in organisms. Consequently, modulating autophagy levels can profoundly impact the survival, death, and regeneration of cells in the inner ear, including hair cells (HCs) and spiral ganglion neurons (SGNs). Abnormal mitochondrial autophagy has been demonstrated in animal models of SNHL. These findings indicate the profound significance of comprehending autophagy while suggesting that our perspective on this cellular process holds promise for advancing the treatment of SNHL. Thus, this review aims to clarify the pathogenic mechanisms of SNHL and the role of autophagy in the developmental processes of various cochlear structures, including the greater epithelial ridge (GER), SGNs, and the ribbon synapse. The pathogenic mechanisms of age-related hearing loss (ARHL), also known as presbycusis, and the latest research on autophagy are also discussed. Furthermore, we underscore recent findings on the modulation of autophagy in SNHL induced by ototoxic drugs. Additionally, we suggest further research that might illuminate the complete potential of autophagy in addressing SNHL, ultimately leading to the formulation of pioneering therapeutic strategies and approaches for the treatment of deafness.

Extracellular ATP accelerates cell death and decreases tight junction protein ZO-1 in hypoxic cochlear strial marginal cells in neonatal rats.

In the cochlea, extracellular ATP (eATP) plays an important role in both physiological and pathological processes, but its role in the hypoxic cochlea remains unclear. The present study aims to investigate the relationship between eATP and hypoxic marginal cells (MCs) in the stria vascularis in cochlea. Combining various methodologies, we found that eATP accelerates cell death and decreases tight junction protein zonula occludens-1 (ZO-1) in hypoxic MCs. Flow cytometry and western blot analyses revealed an increase in apoptosis levels and suppression of autophagy, indicating that eATP causes additional cell death by increasing the apoptosis of hypoxic MCs. Given that autophagy inhibits apoptosis to protect MCs under hypoxia, apoptosis is probably enchanced by suppressing autophagy. Interleukin-33(IL-33)/suppression of tumorigenicity-2(ST-2)/matrix metalloprotein 9(MMP9) pathway activation was also observed during the process. Further experiments involving the use of additional IL-33 protein and an MMP9 inhibitor indicated that this pathway is responsible for the damage to the ZO-1 protein in hypoxic MCs. Our study revealed an adverse effect of eATP on the survival and ZO-1 protein expression of hypoxic MCs, as well as the underlying mechanism.

[Serum Level of MiR-609 and Its Clinical Prognostic Value in Patients with Thalassemia].

OBJECTIVE: To investigate the level of serum microRNA-609 and its clinical prognostic value in patients with thalassemia. METHODS: One hundred and twenty-seven patients with thalassemia treated in our hospital from April 2017 to April 2018 were selected, 100 healthy persons were selected as control group. The changes of miR-609 were analyzed by RT-PCR, the relationship between miR-609 and clinical indicators of thalassemia was analyzed, and the prognostic risk factors of thalassemia were evaluated by multivariate logistic regression analysis. RESULTS: The relative expression level of miR-609 in thalassemia patients was 3.17±0.24, which was significantly higher than that in control group (P<0.05). The levels of ALT, Plt and MCH in patients with high expression of miR-609 were significantly higher than those in patients with low expression of miR-609 (P<0.05). The levels of Hb and sICAM-1 in patients with high expression of miR-609 were significantly lower than those in patients with low expression of miR-609 (P<0.05). There was no correlation between the level of miR-609 and the patient's sex, age and AST (P>0.05). The incidence rate of mild anemia in high expression group was significantly lower than that in low expression group (P<0.05). There was no correlation between the level of miR-609 and the incidence rate of moderate anemia (P>0.05). The number of patients with severe anemia in the miR-609 high expression group was higher than that in miR-609 low expression group (P<0.05). The incidence rate of dizziness, fatigue and fever in patients with miR-609 high expression group was significantly higher than those in patients with miR-609 low expression (P<0.05). There was no correlation between the level of miR-609 and the incidence rate of nausea in patients with thalassemia. ROC curve showed that the AUC value of microRNA-609 was 0.862, the sensitivity was 83.6%, and the specificity was 84.1%, which suggested that miR-609 had a high diagnostic value for thalassemia. Multivariate logistic regression analysis showed that MCH and mir-609 were risk factors for poor prognosis of thalassemia patients. CONCLUSION: The increased level of serum miR-609 in patients with thalassemia is a risk factor for poor prognosis and can be used as a reference index for evaluating the efficacy for patients.

[Analysis of Irregular Antibody Production in Severe ß-Thalassemia Children with long-term Blood Transtusion and Its Correlation with RH Gene and Anemia Gene Mutation Site].

OBJECTIVE: To analyze the prevalence of irregular antibodies in children with severe ß-thalassemia after long-term blood transfusion and its correlation with RH and anemia gene mutations site. METHODS: One hundred twenty children with severe ß-thalassemia and long-term blood transfusion were selected in our hospital, the genomic DNA was extracted and the genotype of RH factor were determined by PCR-SSP. The irregular antibodies and their types were screened and identified by the serological method, the gene types of the severe ß-thalassemia were analyzed by reverse dot blot hybridization on DNA chip and PCR amplification. RESULTS: The major of RH genotypes in 120 children were Ce/Ce (59.17%) and CE/ce (25%), among them 10 children possessed the positive irregular antibodies (8.33%), out of these 10 children, the genotypes of RH factor were Ce/Ce in 6 cases, cE/cE, CE/ce, cE/ce and Ce/ce in one case; among these 10 children with positive irregular antibodies, the anemia gene mutations were IVs-11654M in 2 cases, cD4142M in 6 cases, 28M in 1 case, and CD71-72M in 1 case. CONCLUSION: Irregular antibodies produced by regular blood transfusion in children with severe ß-thalassemia may be related with RH factor and anemia gene mutation sites.