Effect of Sodium Salicylate on Calcium Currents and Exocytosis in Cochlear Inner Hair Cells: Implications for Tinnitus Generation

A Novel Functional Method of Protector Screening for Zebrafish Lateral Line Hair Cells via the Acoustic Escape Response

Zebrafish larvae are useful for identifying chemicals against lateral line (LL) hair cell (HC) damage and this type of chemical screen mainly focuses on searching for protectors against cell death. To expand the candidate pool of HC protectors, a self-built acoustic escape response (AER)-detecting system was developed to apply both low-frequency near-field sound transmission and AER image acquisition/processing modules. The device quickly confirmed the changed LL HC functions caused by most known ototoxins, protectors, and neural transmission modifiers, or knockdown of LL HC-expressing genes. With ten devices wired in tandem, five 'hit' chemicals were identified from 124 cyclin-dependent kinase inhibitors to partially restore cisplatin-damaged AER in less than a day. AS2863619, ribociclib, and SU9516 among the hits, protected the HCs in the mouse cochlea. Therefore, using free-swimming larval zebrafish, the self-made AER-detecting device can efficiently identify compounds that are protective against HC damage, including cell death and loss-of-function.

A Clinical Evaluation of Calcium and Fluoride Supplementation for Tinnitus in Non-Surgical Otosclerosis: Insights from a Tertiary Care Center in Romania

Background and Objectives: The management of chronic tinnitus in patients with otosclerosis presents a considerable clinical challenge, particularly as to those who are either ineligible for or reluctant to undergo surgical interventions. Surgical interventions improve hearing levels and may provide relief from tinnitus; however, medical research is also focused on alternative non-surgical treatments aimed at symptomatic improvement. This is particularly relevant, considering that otosclerosis currently has no definitive cure, despite the existence of various surgical techniques and oral therapies. This study evaluates the effects of oral calcium and fluoride supplementation on tinnitus severity in otosclerosis patients who opted for non-surgical management. Materials and Methods: A total of 128 otosclerosis patients with tinnitus were included in this study, which was conducted over a five-year period. Patients were categorized into three groups based on the severity of their tinnitus (mild, moderate and severe), as assessed by the Tinnitus Handicap Inventory (THI). Patients in all three groups received Florical (Mericon Industries, Inc., Peoria, IL, USA), a calcium and fluoride supplement, and were monitored over three months. The severity of tinnitus was reassessed following supplementation. Statistical analyses were conducted to further investigate patient scores. Results: Evaluating patients based on the severity of their tinnitus, we consistently observed clinically significant reductions in THI scores, specifically a decrease of 10 points or more, among those with mild tinnitus. The moderate group exhibited a lower degree of reduction in their THI scores, while the severe group appeared to be unaffected. Statistical analyses reveal a significant correlation between the reduction of tinnitus and the supplementation of Florical, as the severity of tinnitus decreases. Conclusions: The present study suggests that oral calcium and fluoride supplementation may serve as a promising non-surgical approach for tinnitus management in otosclerosis (particularly in patients with mild symptoms), in addition to its marketing-indicated role, supporting the preservation of hearing levels in otosclerosis. Its efficacy seems to diminish as tinnitus severity increases, further pointing out a potential preventative role of this supplementation.

Sodium salicylate ameliorates exercise-induced muscle damage in mice by inhibiting NF-kB signaling

BACKGROUND

Eccentric muscle contraction can cause muscle damage, which reduces the efficiency of exercise. Previous evidence suggested that Sodium salicylate (SS) could improve the repair of aged muscle. This study intends to investigate whether SS can impact skeletal muscle damage caused by eccentric exercise.

METHODS

Eccentric treadmill exercise was performed to induce muscle damage in mice. Plasma levels of muscle damage markers were estimated. RT-qPCR was employed for detecting mRNA levels of proinflammatory mediators in murine gastrocnemius muscle. Immunofluorescence staining of laminin/DAPI was utilized for quantifying centrally nucleated myofibers in the gastrocnemius muscle. Western blotting was implemented to examine protein levels of mitsugumin 53 (MG53), matrix metalloproteinase (MMP)-2/9, and NF-κB signaling-related markers.

RESULTS

SS administration reduced muscle damage marker production in the plasma and decreased the levels of proinflammatory mediators, MG53 and MMP-2/9 in mice after exercise. SS alleviated the severity of muscle damage in the gastrocnemius of mice after eccentric exercise. SS blocked NF-κB signaling pathway in the gastrocnemius muscle.

CONCLUSION

SS administration ameliorates skeletal muscle damage caused by eccentric exercise in the mouse model.

Acoustic and optoacoustic stimulations in auditory brainstem response test in salicylate induced tinnitus

As a common debilitating disorder worldwide, tinnitus requires objective assessment. In the auditory brainstem response (ABR) test, auditory potentials can be evoked by acoustic or optoacoustic (induced by laser light) stimulations. In order to use the ABR test in the objective assessment of tinnitus, in this study, acoustic ABR (aABR) and optoacoustic ABR (oABR) were compared in the control and tinnitus groups to determine the changes caused by sodium salicylate (SS)-induced tinnitus in rat. In both aABR and oABR, wave II was the most prominent waveform, and the amplitude of wave II evoked by oABR was significantly higher than that of aABR. Brainstem transmission time (BTT), which represents the time required for a neural stimulation to progress from the auditory nerve ending to the inferior colliculus, was significantly shorter in oABR. In the tinnitus group, there was a significant increase in the threshold of both ABRs and a significant decrease in the amplitude of wave II only in the oABR. Based on our findings, the ABR test has the potential to be used in the assessment of SS-induced tinnitus, but oABR has the advantages of producing more prominent waveforms and significantly reducing the amplitude of wave II in tinnitus.