Schisandrin B protect inner hair cells from cisplatin by inhibiting celluar oxidative stress and apoptosis.

Cisplatin is an effective chemotherapeutic agent; however, ototoxicity is one of its negative effects that greatly limits the use of cisplatin in clinical settings. Previous research has shown that the most important process cisplatin damage to inner ear cells, such as hair cells (HCs), is the excessive production and accumulation of ROS. Schisandrin B (SchB), is a low-toxicity, inexpensive, naturally occurring antioxidant with a variety of pharmacological effects. Therefore, the potential antioxidant effects of SchB may be useful for cisplatin ototoxicity treatment. In this study, the effects of SchB on cochlear hair cell viability, ROS levels, and expression of apoptosis-related molecules were evaluated by CCK-8, immunofluorescence, flow cytometry, and qRT-PCR, as well as auditory brainstem response (ABR) and dysmorphic product otoacoustic emission (DPOAE) tests to assess the effects on inner ear function. The results showed that SchB treatment increased cell survival, prevented apoptosis, and reduced cisplatin-induced ROS formation. SchB treatment reduced the loss of cochlear HCs caused by cisplatin in exosome culture. In addition, SchB treatment attenuated cisplatin-induced hearing loss and HC loss in mice. This study demonstrates the ability of SchB to inhibit cochlear hair cell apoptosis and ROS generation and shows its potential therapeutic effect on cisplatin ototoxicity.

RUNX1-BMP2 promotes vasculogenic mimicry in laryngeal squamous cell carcinoma via activation of the PI3K-AKT signaling pathway.

BACKGROUND: Laryngeal squamous cell carcinoma (LSCC) is one of the most common malignant tumors of the head and neck. Vasculogenic mimicry (VM) is crucial for tumor growth and metastasis and refers to the formation of fluid channels by invasive tumor cells rather than endothelial cells. However, the regulatory mechanisms underlying VM during the malignant progression of LSCC remain largely unknown. METHODS: Gene expression and clinical data for LSCC were obtained from the TCGA and Gene GEO (GSE27020) databases. A risk prediction model associated with VM was established using LASSO and Cox regression analyses. Based on their risk scores, patients with LSCC were categorized into high- and low-risk groups. The disparities in immune infiltration, tumor mutational burden (TMB), and functional enrichment between these two groups were examined. The core genes in LSCC were identified using the machine learning (SVM-RFE) and WGCNA algorithms. Subsequently, the involvement of bone morphogenetic protein 2 (BMP2) in VM and metastasis was investigated both in vitro and in vivo. To elucidate the downstream signaling pathways regulated by BMP2, western blotting was performed. Additionally, ChIP experiments were employed to identify the key transcription factors responsible for modulating the expression of BMP2. RESULTS: We established a new precise prognostic model for LSCC related to VM based on three genes: BMP2, EPO, and AGPS. The ROC curves from both TCGA and GSE27020 validation cohorts demonstrated precision survival prediction capabilities, with the nomogram showing some net clinical benefit. Multiple algorithm analyses indicated BMP2 as a potential core gene. Further experiments suggested that BMP2 promotes VM and metastasis in LSCC. The malignant progression of LSCC is promoted by BMP2 via the activation of the PI3K-AKT signaling pathway, with the high expression of BMP2 in LSCC resulting from its transcriptional activation by runt-related transcription factor 1 (RUNX1). CONCLUSION: BMP2 predicts poor prognosis in LSCC, promotes LSCC VM and metastasis through the PI3K-AKT signaling pathway, and is transcriptionally regulated by RUNX1. BMP2 may be a novel, precise, diagnostic, and therapeutic biomarker of LSCC.

Gene expression analysis of oxidative stress-related genes in the apical, middle, and basal turns of the cochlea.

It can be observed from aminoglycoside-induced hair cell damage that the cochlea basal turn is more susceptible to trauma than the apex. Drug-induced hearing loss is closely related to oxidative damage. The basilar membrane directly exposed to these ototoxic drugs exhibits differences in damage, indicating that there is an inherent difference in the sensitivity to oxidative damage from the apex to the base of the cochlea. It has been reported that the morphology and characteristics of the cochlea vary from the apex to the base. Therefore, we investigated oxidative stress-related gene expression profiles in the apical, middle, and basal turns of the cochlea. The Oxidative Stress RT2 Profiler™ PCR Array revealed that three of the 84 genes (Mb, Mpo, and Ncf1) were upregulated in the middle turn compared to their level in the apical turn. Moreover, eight genes (Mb, Duox1, Ncf1, Ngb, Fmo2, Gpx3, Mpo, and Gstk1) were upregulated in the basal turn compared to their level in the apical turn. The qPCR verification data were similar to that of the PCR Array. We found that MPO was expressed in the rat cochlea and protected against gentamicin-induced hair cell death. This study summarized the data for the gradient of expression of oxidative stress-related genes in the cochlea and found potential candidate targets for prevention of ototoxic deafness, which may provide new insights for cochlear pathology.

Lysophosphatidic acid exerts protective effects on HEI-OC1 cells against cytotoxicity of cisplatin by decreasing apoptosis, excessive autophagy, and accumulation of ROS.

Lysophosphatidic acid (LPA) is an active phospholipid signaling molecule that binds to six specific G protein-coupled receptors (LPA1-6) 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 LPA3 were expressed in HEI-OC1 cells, and the mRNA expression level of LPA1 receptor was significantly higher than that of other receptors. When LPA1 receptor was silenced, the protective effect of LPA was reduced and the proportion of apoptosis cells was increased, indicating that LPA-LPA1 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.

PTEN inhibitor bisperoxovanadium protects against noise-induced hearing loss.

Studies have shown that phosphatase and tensin homolog deleted on chromosome ten (PTEN) participates in the regulation of cochlear hair cell survival. Bisperoxovanadium protects against neurodegeneration by inhibiting PTEN expression. However, whether bisperoxovanadium can protect against noise-induced hearing loss and the underlying mechanism remains unclear. In this study, we established a mouse model of noise-induced hearing loss by exposure to 105 dB sound for 2 hours. We found that PTEN expression was increased in the organ of Corti, including outer hair cells, inner hair cells, and lateral wall tissues. Intraperitoneal administration of bisperoxovanadium decreased the auditory threshold and the loss of cochlear hair cells and inner hair cell ribbons. In addition, noise exposure decreased p-PI3K and p-Akt levels. Bisperoxovanadium preconditioning or PTEN knockdown upregulated the activity of PI3K-Akt. Bisperoxovanadium also prevented H2O2-induced hair cell death by reducing mitochondrial reactive oxygen species generation in cochlear explants. These findings suggest that bisperoxovanadium reduces noise-induced hearing injury and reduces cochlear hair cell loss.

VDR Regulates BNP Promoting Neurite Growth and Survival of Cochlear Spiral Ganglion Neurons through cGMP-PKG Signaling Pathway.

Spiral ganglion neurons (SGNs) are important for hearing, and their peripheral and central processes connect sensory cells of the Corti organ to the central nervous system. The resulting network forms a point-to-point auditory conduction. As a cardiac hormone, brain natriuretic peptide (BNP) binds to natriuretic peptide receptor type A leading to diuresis, vasodilatation, inhibition of renin and aldosterone production, and cardiac and vascular myocyte growth. This study primarily aimed to explore the expression and function of BNP in the rat's inner ear and elucidate its regulatory mechanism. We determined the expression and function of BNP and found that the vitamin D receptor (VDR) could upregulate the expression of BNP and enhance its function. In SGNs of the rat inner ear, BNP promotes neuron survival and prolongs neurite length through the cGMP-PKG signaling pathway, which could be regulated by VDR and provide a novel approach for neuronal regeneration therapy. To the best of our knowledge, this is the first study to report this potential transcriptional regulatory relationship and will act as a reference for research on neuronal regeneration therapy for SGNs injury.

Development and evaluation of a three-step automatic planning technique for lung SBRT based on performance examination of advanced settings in Pinnacle's auto-planning module.

The benefits of Pinnacle's auto-planning module on clinical practice have been well documented. However, little is known regarding the efficiency of its Advanced Settings and the practicality of incorporating this module into Stereotactic Body Radiation Therapy (SBRT), which is why this research was conducted. To characterize the impact of Advanced Settings on plan quality, a total of 25 previously delivered postoperative cervical cases were re-planned and evaluated. Then a three-step automatic planning technique was developed and tested on ten lung SBRT cases based on the investigation. The differences between plans with fine-tuned Advanced Settings and the default were compared using a Wilcoxon signed-rank test with a significance threshold of 5%. The same statistical analysis was implemented to examine the quality variations in manual and automatic SBRT planning. When the Tuning Balance, Dose Fall-Off Margin, and Hot-Spot Maximum Goal were set to 100%, 1 cm, and 250%, respectively, better organ-at-risk (OAR) sparing was reached, but target quality was compromised. The OAR dose reduction and target homogeneity deterioration showed a strong correlation. The three-step methodology improved high dose spillage while saving time, with statistically significant reductions of 66.7% in V105% of non-PTV and 58.1% in planning time to the human-driven strategy. Except for urgent requirements for sparing OARs or processing SBRT plans, keeping the default is appropriate for Advanced Settings. The three-step methodology automatically searches for the available solution with purposeful Advanced Settings adjustments, demonstrating its ability to produce high-quality plans in less time. For the inexperienced or under-resourced clinics, our procedure can be introduced as a robust and handy strategy in SBRT, notably for expedited quality planning.

A novel splice site variant c.1183 + 1 G > C in DFNA5 causing autosomal dominant nonsyndromic hearing loss in a Chinese family.

BACKGROUND: The most frequent clinical presentation of autosomal dominant nonsyndromic hearing loss (ADNSHL) is bilateral, symmetrical, postlingual progressive sensorineural hearing loss, which begins with impairment at high frequencies and eventually progresses to hearing loss at all frequencies. Autosomal dominant deafness-5 (DFNA5) is a subtype of ADNSHL caused by heterozygous variants in the gasdermin E (GSDME, also known as DFNA5) gene. METHODS: Deafness gene NGS panel analysis were performed on the proband of a six-generation Chinese family with hearing loss. The co-segregation analysis between the hearing loss and the novel variant was analyzed by Sanger sequencing and pure-tone audiometry. The minigene splicing assay was performed to evaluate the potential effect of the variant on messenger RNA splicing in vitro. RESULTS: The family exhibited autosomal dominant, progressive, postlingual, nonsyndromic sensorineural hearing loss, which was similar to that of the previously reported DFNA5 families. A novel heterozygous splice site variant in GSDME gene intron 8 was identified, which co-segregated with the hearing loss phenotype of the family. The variant caused skipping of exon 8 in the mutant transcript, leading to the direct linking of exons 7 and 9. CONCLUSIONS: We identified a novel GSDME splice site variant c.1183 + 1 G > C in an extended Chinese family, which led to the skipping of exon 8. The results extended the pathogenic variants spectrum of the GSDME gene, provided further support for the 'gain-of-function' mechanism of DFNA5, and afforded a molecular interpretation for these patients with ADNSHL.

A forskolin-loaded nanodelivery system prevents noise-induced hearing loss.

Hearing loss is the most common sensory disorder worldwide and may result from age, drugs, or exposure to excessive noise. Crossing the blood-labyrinth barrier to achieve targeted drug delivery to the inner ear is key to the treatment of hearing loss. We designed a nanoparticle (NP)-based system for targeted drug delivery of forskolin (FSK) to the inner ear, driven by the prestin-targeting peptide LS19 ("ligand-receptor type interaction"). In vivo experiments in developing zebrafish embryos (4-96 h past fertilization) and mice confirmed that LS19-FSK specifically targeted and accumulated in zebrafish lateral line neuromasts and mouse outer hair cells (OHCs). LS19 peptide modification enabled LS19-FSK-NPs to rapidly target OHCs with high specificity. Furthermore, the multifunctional LS19-FSK-NPs were successfully delivered to the OHCs via the round window membrane route and exhibited slow-release properties. The sustained release and intracellular accumulation of FSK inhibited apoptosis of OHCs. Compared with LS19-NPs and FSK-NPs, LS19-FSK-NPs provided significantly stronger protection against noise-induced hearing damage, based on auditory brainstem responses at 4, 8, 16, and 32 kHz. Thus, our specially designed targeted nano-delivery system may serve as a basis for future clinical applications and treatment platforms and has the potential to significantly improve the treatment results of many inner ear diseases.

Expression and distribution of Nob1 in the developing rat cochleae.

BACKGROUND: Mammalian inner ear cells are produced during embryonic development. NIN1/RPN12 binding protein 1 homolog (Nob1), a ribosome assembly factor, is believed to be involved in transcriptional regulation and may play an important role in mediating certain physiological and pathological functions. METHODS: We investigated the expression levels and distribution patterns of Nob1 in rat cochlea at different developmental stages using reverse transcription-polymerase chain reaction (RT-PCR), Western blot analysis, and immunofluorescence microscopy (P0, P3, P7, P14, and P30, n = 11 per age group). RESULTS: The expression of Nob1 was gradually upregulated from Postnatal day (P) 0 to P14 and stabilized at P30. Our results analyzing Nob1 expression at P0 and P3 in the rat cochleae revealed expression in the greater epithelial ridge cells, lesser epithelial ridge cells, and spiral ganglion neurons (SGNs), whereas low levels of Nob1 expression were observed in the stria vascularis cells. During the development of the cochlea, the organ of Corti undergoes dramatic architectural remodeling. Nob1 expression was stably detected in supporting cells and hair cells from P7 to P30, and its expression gradually increased in the SGNs. CONCLUSIONS: Thus, the present study revealed that upregulation of Nob1 might explain the maturation of the cytoarchitecture in the cochlea during the postnatal period, and a complete understanding of its function in the mammalian inner ear may help to develop strategies to resolve auditory hair cell loss.

A novel KCNQ4 gene variant (c.857A>G; p.Tyr286Cys) in an extended family with non­syndromic deafness 2A.

Deafness is one of the most common sensory disorders found in humans; notably, >60% of all cases of deafness have been attributed to genetic factors. Variants in potassium voltage­gated channel subfamily Q member 4 (KCNQ4) are etiologically linked to a type of progressive hearing loss, deafness non­syndromic autosomal dominant 2A (DFNA2A). In the present study, whole­exome sequencing (WES) was performed on three members of a five­generation Chinese family with 46 members with hearing loss. Pure tone audiometry and Sanger sequencing were performed for 11 family members to determine whether the novel variant in the KCNQ4 gene was segregated with the affected family members. In addition, evolutionary conservation analysis and computational tertiary structure protein prediction of the wild­type KCNQ4 protein and its variant were performed. The family exhibited autosomal dominant, progressive, post­lingual, non­syndromic sensorineural hearing loss. A novel co­segregating heterozygous missense variant (c.857A>G; p.Tyr286Cys) in the glycine­tyrosine­glycine signature sequence in the pore region of the KCNQ4 channel was identified. This variant was predicted to result in a tyrosine­to­cysteine substitution at position 286 in the KCNQ4 protein. The tyrosine at position 286 is well conserved across different species. The substitution of tyrosine with cysteine would affect the structure of the pore region, resulting in the loss of channel function. The KCNQ4 gene is one of the most common mutated genes observed in patients with autosomal dominant, non­syndromic hearing loss. Taken together, for the family analyzed in the present study, performing WES in conjunction with Sanger sequencing has led to the detection of a novel, potentially causative variant (c.857 A>G; p.Tyr286Cys) in exon 6 of the KCNQ4 gene. The present study has added to the number of pathogenic variants observed in the KCNQ4 gene, and the findings may prove to be useful for both the diagnosis of DFNA2A and in the design of early interventional therapies.

Development of nanoparticle drug-delivery systems for the inner ear.

Hearing loss has become the most common sensory nerve disorder worldwide, with no effective treatment strategy. Low-permeability and limited blood supply to the blood-labyrinth barrier limit the effective delivery and efficacy of therapeutic drugs in the inner ear. Nanoparticle (NP)-based drugs have shown benefits of stable controlled release and functional surface modification, and NP-based delivery systems have become a research hotspot. In this review, we discuss the development of new targeted drug-delivery systems based on the biocompatibility and safety of different NPs in the cochlea, as well as the advantages and disadvantages of their prescription methods and approaches. We believe that targeted NP-based drug-delivery systems will be effective treatments for hearing loss.

[Effect of tympanoplasty on wet ear with different mucosal status of tympanic cavity].

Objective:A retrospective analysis of audiologic outcome and graft take rate on post-tympanoplasty with different middle ear mucosal conditions in wet ear. Method:According to the characteristics of middle ear mucosal condition and residual eardrum, 80 cases with wet ear of chronic suppurative otitis media were divided into the hydrocele group, the swelling group and the granulation group. The factors in different groups, including gender, age, disease course, sides, size and location of perforations, destruction of ossicular chain and reconstruction methods were analyzed. Moreover, postoperative hearing improvement and graft take rate were compared among the three groups. Result:There was no significant difference in gender, age, disease course, sides, size and location of perforations among the hydrocele group, the swelling group and the granulation group （P>0.05）. Overall, the postoperative average Air-Bone Gaps（ABG） were reduced in all wet ear patients after surgery （P<0.01）. The ABG was decreased from （25.5 ± 10.8） dB to（15.4 ± 9.4） dB in the hydrocele group, and decreased from （27.6 ± 8.7） dB to （15.2 ± 9.6） dB in the swelling group, and from （29.5 ± 7.7） dB to （17.2 ± 17.2） dB in the granulation group. The graft take rates were 90.0% in totally. There were no significant difference in graft take rates among the three groups, and 84.6% in the hydrocele group, 93.3% in the swelling group and 100.0% in the swelling group（P>0.05）. Conclusion:Wet ear is not an absolute contraindication of tympanoplasty for chronic suppurative otitis media. Whether there was effusion, swelling or granulomatous hyperplasia in the tympanoplasty, the patients'hearing improved significantly after tympanoplasty, and the healing rate of the tympanoplasty did not decrease. Further basic and clinical studies are needed to standardize the timing of wet ear surgery, clarify the operative contraindication and elucidate the pathophysiological mechanism of eardrum healing.

[Reconstruction of wrist joint by transplanting fibular head pedicled with lateral inferior genicular artery].

OBJECTIVE: To investigate a new operative method to reconstruct wrist joint for treating the defect of the distal radius after excision of tumor. METHODS: From October 1999 to December 2001, 3 cases of giant cell tumor in the distal radius were resected and the wrist joint was reconstructed by transplanting the fibular head pedicled with the lateral inferior genicular artery. RESULTS: After followed up for 6 to 18 months, all patients achieved the bony healing within 4 months without tumor relapse and had good function of the wrist joint. CONCLUSION: This operation is simple and reliable. The fibular head can be cut according to the tumor size of the radius.