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Cell Death Discovery Nov 2023Lysophosphatidic acid (LPA) is an active phospholipid signaling molecule that binds to six specific G protein-coupled receptors (LPA) on the cell surface and exerts a...
Lysophosphatidic acid (LPA) is an active phospholipid signaling molecule that binds to six specific G protein-coupled receptors (LPA) on the cell surface and exerts a variety of biological functions, including cell migration and proliferation, morphological changes, and anti-apoptosis. The earliest study from our group demonstrated that LPA treatment could restore cochlear F-actin depolymerization induced by noise exposure, reduce hair cell death, and thus protect hearing. However, whether LPA could protect against cisplatin-induced ototoxicity and which receptors play the major role remain unclear. To this end, we integrated the HEI-OC1 mouse cochlear hair cell line and zebrafish model, and found that cisplatin exposure induced a large amount of reactive oxygen species accumulation in HEI-OC1 cells, accompanied by mitochondrial damage, leading to apoptosis and autophagy. LPA treatment significantly attenuated autophagy and apoptosis in HEI-OC1 cells after cisplatin exposure. Further investigation revealed that all LPA receptors except LPA were expressed in HEI-OC1 cells, and the mRNA expression level of LPA receptor was significantly higher than that of other receptors. When LPA receptor was silenced, the protective effect of LPA was reduced and the proportion of apoptosis cells was increased, indicating that LPA-LPA plays an important role in protecting HEI-OC1 cells from cisplatin-induced apoptosis. In addition, the behavioral trajectory and in vivo fluorescence imaging results showed that cisplatin exposure caused zebrafish to move more actively, and the movement speed and distance were higher than those of the control and LPA groups, while LPA treatment reduced the movement behavior. Cisplatin caused hair cell death and loss in zebrafish lateral line, and LPA treatment significantly protected against hair cell death and loss. LPA has a protective effect on hair cells in vitro and in vivo against the cytotoxicity of cisplatin, and its mechanism may be related to reducing apoptosis, excessive autophagy and ROS accumulation.
PubMed: 37968255
DOI: 10.1038/s41420-023-01706-5 -
Seminars in Hearing Nov 2023For more than 50 years, the National Institute for Occupational Safety and Health (NIOSH), part of the United States (U.S.) Centers for Disease Control and Prevention... (Review)
Review
For more than 50 years, the National Institute for Occupational Safety and Health (NIOSH), part of the United States (U.S.) Centers for Disease Control and Prevention (CDC), has been actively working to reduce the effects of noise and ototoxic chemicals on worker hearing. NIOSH has pioneered basic and applied research on occupational hearing risks and preventive measures. The Institute has issued recommendations and promoted effective interventions through mechanisms ranging from formal criteria documents to blogs and social media. NIOSH has conducted surveillance and published statistics to guide policy and target prevention efforts. Over the past five decades, substantial progress has been made in raising awareness of noise as a hazard, reducing the risk of occupational hearing loss, improving the use of hearing protection, and advancing measurement and control technologies. Nevertheless, noise remains a prevalent workplace hazard and occupational hearing loss is still one of the most common work-related conditions. NIOSH continues to work toward preventing the effects of noise and ototoxicants at work and has many resources to assist audiologists in their hearing loss prevention efforts.
PubMed: 37818146
DOI: 10.1055/s-0043-1769499 -
International Journal of Molecular... Oct 2023With more than 466 million people affected, hearing loss represents the most common sensory pathology worldwide. Despite its widespread occurrence, much remains to be... (Review)
Review
With more than 466 million people affected, hearing loss represents the most common sensory pathology worldwide. Despite its widespread occurrence, much remains to be explored, particularly concerning the intricate pathogenic mechanisms underlying its diverse phenotypes. In this context, metabolomics emerges as a promising approach. Indeed, lying downstream from molecular biology's central dogma, the metabolome reflects both genetic traits and environmental influences. Furthermore, its dynamic nature facilitates well-defined changes during disease states, making metabolomic analysis a unique lens into the mechanisms underpinning various hearing impairment forms. Hence, these investigations may pave the way for improved diagnostic strategies, personalized interventions and targeted treatments, ultimately enhancing the clinical management of affected individuals. In this comprehensive review, we discuss findings from 20 original articles, including human and animal studies. Existing literature highlights specific metabolic changes associated with hearing loss and ototoxicity of certain compounds. Nevertheless, numerous critical issues have emerged from the study of the current state of the art, with the lack of standardization of methods, significant heterogeneity in the studies and often small sample sizes being the main limiting factors for the reliability of these findings. Therefore, these results should serve as a stepping stone for future research aimed at addressing the aforementioned challenges.
Topics: Animals; Humans; Reproducibility of Results; Hearing Loss; Deafness; Metabolomics; Metabolome
PubMed: 37894867
DOI: 10.3390/ijms242015188 -
Journal of Cystic Fibrosis : Official... Sep 2023Aminoglycosides (AGs), such as tobramycin, are essential antibiotics in the management of pulmonary infections in patients with cystic fibrosis (CF). They induce...
BACKGROUND
Aminoglycosides (AGs), such as tobramycin, are essential antibiotics in the management of pulmonary infections in patients with cystic fibrosis (CF). They induce ototoxicity without the relationship being clearly described in the literature. Our aim is to propose a mathematical and statistical model describing the relationship between the estimated cumulative exposure (Area Under the Curve, AUC) to tobramycin and ototoxicity with audiogram interpretation in young patients with CF.
METHODS
Cumulative AUCs were estimated for each course of tobramycin, for the 106 individuals with CF (between 4 and 22 years of age) enrolled in this retrospective study (35 who had received IV tobramycin, 71 controls). Mean hearing loss was calculated for each audiogram and a statistical model was developed to predict hearing loss.
RESULTS
The model confirms a significant relationship between cumulative tobramycin exposure and changes in hearing acuity: Meanhearingloss=2.7+(3×10)×AUC_tobramycin+individual_susceptibility However, the ototoxic effect is not clinically perceptible (mean hearing loss: 3.8 dB). The impact of AUC on hearing loss is minor in these subjects who received a limited number of courses of tobramycin (median: 5 courses).
CONCLUSION
A significant relationship between cumulative exposure to tobramycin and ototoxicity was demonstrated. Individual treatment susceptibility should not be overlooked. As ototoxicity is not clinically perceptible in the study subjects, hearing tests should be continued during adulthood to provide individualized medical guidance and to obtain a lifetime analysis of the relationship between exposure and hearing loss.
Topics: Humans; Adult; Tobramycin; Retrospective Studies; Cystic Fibrosis; Ototoxicity; Anti-Bacterial Agents; Hearing Loss
PubMed: 37088635
DOI: 10.1016/j.jcf.2023.04.002 -
International Journal of Molecular... Jun 2024Our study aimed to investigate the role of ferroptosis in sevoflurane-induced hearing impairment and explore the mechanism of the microRNA-182-5p...
Our study aimed to investigate the role of ferroptosis in sevoflurane-induced hearing impairment and explore the mechanism of the microRNA-182-5p (miR-182-5p)/Glutathione Peroxidase 4 (GPX4) pathway in sevoflurane-induced ototoxicity. Immunofluorescence staining was performed using myosin 7a and CtBP2. Cell viability was assessed using the CCK-8 kit. Fe concentration was measured using FerroOrange and Mi-to-FerroGreen fluorescent probes. The lipid peroxide level was assessed using BODIPY 581/591 C11 and MitoSOX fluorescent probes. The auditory brainstem response (ABR) test was conducted to evaluate the hearing status. Bioinformatics tools and dual luciferase gene reporter analysis were used to confirm the direct targeting of miR-182-5p on GPX4 mRNA. GPX4 and miR-182-5p expression in cells was assessed by qRT-PCR and Western blot. Ferrostatin-1 (Fer-1) pretreatment significantly improved hearing impairment and damage to ribbon synapses in mice caused by sevoflurane exposure. Immunofluorescence staining revealed that Fer-1 pretreatment reduced intracellular and mitochondrial iron overload, as well as lipid peroxide accumulation. Our findings indicated that miR-182-5p was upregulated in sevoflurane-exposed HEI-OC1 cells, and miR-182-5p regulated GPX4 expression by binding to the 3'UTR of GPX4 mRNA. The inhibition of miR-182-5p attenuated sevoflurane-induced iron overload and lipid peroxide accumulation. Our study elucidated that the miR-182-5p/GPX4 pathway was implicated in sevoflurane-induced ototoxicity by promoting ferroptosis.
Topics: Ferroptosis; MicroRNAs; Sevoflurane; Phospholipid Hydroperoxide Glutathione Peroxidase; Animals; Mice; Ototoxicity; Signal Transduction; Cell Line; Male; Hearing Loss; Mice, Inbred C57BL; Phenylenediamines; Cyclohexylamines
PubMed: 38928480
DOI: 10.3390/ijms25126774 -
Hepatology (Baltimore, Md.) Jul 2024Hepatoblastoma (HB) is the predominant form of pediatric liver cancer, though it remains exceptionally rare. While treatment outcomes for children with HB have improved,...
BACKGROUND AND AIMS
Hepatoblastoma (HB) is the predominant form of pediatric liver cancer, though it remains exceptionally rare. While treatment outcomes for children with HB have improved, patients with advanced tumors face limited therapeutic choices. Additionally, survivors often suffer from long-term adverse effects due to treatment, including ototoxicity, cardiotoxicity, delayed growth, and secondary tumors. Consequently, there is a pressing need to identify new and effective therapeutic strategies for patients with HB. Computational methods to predict drug sensitivity from a tumor's transcriptome have been successfully applied for some common adult malignancies, but specific efforts in pediatric cancers are lacking because of the paucity of data.
APPROACH AND RESULTS
In this study, we used DrugSense to assess drug efficacy in patients with HB, particularly those with the aggressive C2 subtype associated with poor clinical outcomes. Our method relied on publicly available collections of pan-cancer transcriptional profiles and drug responses across 36 tumor types and 495 compounds. The drugs predicted to be most effective were experimentally validated using patient-derived xenograft models of HB grown in vitro and in vivo. We thus identified 2 cyclin-dependent kinase 9 inhibitors, alvocidib and dinaciclib as potent HB growth inhibitors for the high-risk C2 molecular subtype. We also found that in a cohort of 46 patients with HB, high cyclin-dependent kinase 9 tumor expression was significantly associated with poor prognosis.
CONCLUSIONS
Our work proves the usefulness of computational methods trained on pan-cancer data sets to reposition drugs in rare pediatric cancers such as HB, and to help clinicians in choosing the best treatment options for their patients.
Topics: Hepatoblastoma; Humans; Liver Neoplasms; Transcriptome; Animals; Mice; Male; Child; Female; Antineoplastic Agents; Xenograft Model Antitumor Assays; Computational Biology; Child, Preschool; Gene Expression Profiling
PubMed: 37729391
DOI: 10.1097/HEP.0000000000000601 -
BioRxiv : the Preprint Server For... Nov 2023Cisplatin is known to cause inner ear dysfunction. There is growing evidence that cisplatin-induced demyelination of spiral or Scarpa's ganglion neurons may play an...
OBJECTIVES
Cisplatin is known to cause inner ear dysfunction. There is growing evidence that cisplatin-induced demyelination of spiral or Scarpa's ganglion neurons may play an additional role in drug-induced ototoxicity alongside afferent neuron injury. As Schwann cells produce myelin, there may be an opportunity to reduce ototoxic inner ear damage by promoting Schwann cell viability. This work describes a cellular model of cisplatin-induced Schwann cell injury and investigates the ability of the antioxidant N-acetylcysteine to promote Schwann cell viability. A local delivery system of drug-eluting microparticles was then fabricated, characterized, and investigated for bioactivity.
METHODS
RSC96 rat Schwann cells were dosed with varying concentrations of cisplatin to obtain a dose curve and identify the lethal concentration of 50% of the cells (LC ). In subsequent experiments, RSC96 cells were co-treated with cisplatin and both resuspended or eluted N-acetylcysteine. Cell viability was assessed with the CCK8 assay.
RESULTS
The LC dose of cisplatin was determined to be 3.76 μM (p=2.2 × 10 ). When co-dosed with cisplatin and therapeutic concentration of resuspended or eluted N-acetylcysteine, Schwann cells had an increased viability compared to cells dosed with cisplatin alone.
CONCLUSION
RSC96 Schwann cell injury following cisplatin insult is characterized in this in vitro model. Cisplatin caused injury at physiologic concentrations and N-acetylcysteine improved cell viability and mitigated this injury. N-acetylcysteine was packaged into microparticles and eluted N-acetylcysteine retained its ability to increase cell viability, thus demonstrating promise as a therapeutic to offset cisplatin-induced ototoxicity.
LAY SUMMARY
Cisplatin is a chemotherapeutic agent known to cause balance and hearing problems through damage to the inner ear. This project explored cisplatin injury in a Schwann cell culture model and packaged an antioxidant into microparticles suitable for future drug delivery applications.
PubMed: 37961184
DOI: 10.1101/2023.10.31.564430 -
Frontiers in Psychology 2023Congenital toxoplasmosis (CT) occurs mainly by primary maternal infection during pregnancy. It is estimated that the incidence of vertical transmission to the fetus is...
BACKGROUND
Congenital toxoplasmosis (CT) occurs mainly by primary maternal infection during pregnancy. It is estimated that the incidence of vertical transmission to the fetus is 20% and that infected women are more likely to have a premature birth or low birth weight neonate since there is an association between CT and the rate of premature birth and low birth weight. In addition to severe neurological and ophthalmic consequences, hearing disorders such as hearing loss are also among the clinical manifestations seen in children with CT. Given the above, the objective of this study is to verify what are the auditory disorders seen in children with CT.
METHODS
This literature review was structured according to the PRISMA statement and based on the terms of Study Target Population, Intervention, Comparison, Outcomes, and Study Types (PICOS). To obtain the studies, the following electronic databases were consulted: PubMed, Web of Science, Scopus, and Lilacs. The combined terms used for the search were: ("auditory evoked potentials" OR "hearing" OR "hearing loss") AND ("congenital toxoplasmosis"). The selection of articles was carried out independently, blindly, by two of the authors, to minimize risk of bias.
RESULTS
The search in the databases identified 172 articles, after excluding duplicate articles, 105 studies were identified. From the selection made by reading the titles and abstracts, 11 studies were selected for full-text reading. A total of 94 studies were excluded. An article was selected from the list of references. Therefore, 12 studies were included in the final analysis. It was observed that a significant percentage of studies sought to study the peripheral auditory pathway, verifying the occurrence or association between hearing loss and the presence of congenital infection. Only two studies evaluated the central auditory pathway, using the Brainstem Auditory Evoked Potential (BAEP) and the Frequency Following Response (FFR).
CONCLUSION
Toxoplasmosis affects not only the peripheral areas but central areas as well. Most studies suggest this pathology as a risk factor for both peripheral and central impairment. Research has found a greater association between CT and mild to moderate hearing loss, in addition to alterations in exams such as BAEP and FFR. These data recommend that CT be reported as a global public health problem and can help assess complications and impacts of hearing disorders as a result of CT. There is a gap about studies that retract the co-occurrence between CT and other Risk Indicators for Hearing Loss (RIHL), such as prematurity, permanence in the intensive care unit, and use of ototoxic medications, lack of longitudinal studies, that accompany the development of hearing and language of children with CT, since the consequences of this infection may be late.
PubMed: 38298366
DOI: 10.3389/fpsyg.2023.1286211 -
Scientific Data Apr 2024Our sense of hearing is mediated by cochlear hair cells, of which there are two types organized in one row of inner hair cells and three rows of outer hair cells. Each...
Our sense of hearing is mediated by cochlear hair cells, of which there are two types organized in one row of inner hair cells and three rows of outer hair cells. Each cochlea contains 5-15 thousand terminally differentiated hair cells, and their survival is essential for hearing as they do not regenerate after insult. It is often desirable in hearing research to quantify the number of hair cells within cochlear samples, in both pathological conditions, and in response to treatment. Machine learning can be used to automate the quantification process but requires a vast and diverse dataset for effective training. In this study, we present a large collection of annotated cochlear hair-cell datasets, labeled with commonly used hair-cell markers and imaged using various fluorescence microscopy techniques. The collection includes samples from mouse, rat, guinea pig, pig, primate, and human cochlear tissue, from normal conditions and following in-vivo and in-vitro ototoxic drug application. The dataset includes over 107,000 hair cells which have been identified and annotated as either inner or outer hair cells. This dataset is the result of a collaborative effort from multiple laboratories and has been carefully curated to represent a variety of imaging techniques. With suggested usage parameters and a well-described annotation procedure, this collection can facilitate the development of generalizable cochlear hair-cell detection models or serve as a starting point for fine-tuning models for other analysis tasks. By providing this dataset, we aim to give other hearing research groups the opportunity to develop their own tools with which to analyze cochlear imaging data more fully, accurately, and with greater ease.
Topics: Animals; Mice; Guinea Pigs; Humans; Rats; Swine; Cochlea; Hair Cells, Auditory; Microscopy, Fluorescence; Machine Learning
PubMed: 38653806
DOI: 10.1038/s41597-024-03218-y -
Chinese Medical Journal Mar 2024Cochlear spiral ganglion neurons (SGNs) are bipolar ganglion cells and are the first neurons in the auditory transduction pathway. They transmit complex acoustic...
Cochlear spiral ganglion neurons (SGNs) are bipolar ganglion cells and are the first neurons in the auditory transduction pathway. They transmit complex acoustic information from hair cells to second-order sensory neurons in the cochlear nucleus for sound processing. Injury to SGNs causes largely irreversible hearing impairment because these neurons are highly differentiated cells and cannot regenerate, making treatment of sensorineural hearing loss (SNHL) arising from SGN injury difficult. When exposed to ototoxic drugs or damaging levels of noise or when there is loss of neurotrophic factors (NTFs), aging, and presence of other factors, SGNs can be irreversibly damaged, resulting in SNHL. It has been found that NTFs and stem cells can induce regeneration among dead spiral ganglion cells. In this paper, we summarized the present knowledge regarding injury, protection, and regeneration of SGNs.
Topics: Humans; Spiral Ganglion; Neurons; Cochlea; Hearing Loss, Sensorineural; Hair Cells, Auditory
PubMed: 37407223
DOI: 10.1097/CM9.0000000000002765