scholarly journals Spirulina Prevent Caspase-Independent Apoptosis in the Cochlea and Brainstem of Senescence-Accelerated Prone-8 Mice

2020 ◽  
Author(s):  
Yin-Ching Chan ◽  
Mei-Hsiao Lin ◽  
Juen-Haur Hwang

Abstract Background: Spirulina platensis water extract (SP) could decrease hearing degeneration via reducing oxidative stress damages in the auditory system of senescence-accelerated prone-8 (SAMP8) mice. This study aimed to investigate the effects of SP on the caspase-independent apoptosis in the cochlea and brainstem of SAMP8 mice.Methods: Twelve 11-month-old SAMP8 mice were randomly divided into two groups: control group (SAMP8 mice was fed a normal diet) and spirulina group (SAMP8 mice was fed a normal diet with oral supplementation SP for 6 weeks. Auditory brainstem responses (ABRs) were measured in the beginning and at the end of the study. Cochlear histology and immunochemistry and Western blotting of brainstem were performed at the end of the study.Results: Compared with control group, spirulina group had significantly lower ABR thresholds using click sound stimulation at the end of this study. The spirulina group had significantly higher counts of outer hair cells (OHC) and spiral ganglion neuron (SGN) density in the middle turn of the cochlea. The spirulina group had significantly lower expressions of poly (ADP-ribose) polymerase-1 (PARP-1) and apoptosis-inducing factor (AIF) in the cochlea. Also, the spirulina group had significantly lower expression of PARP-1, but not the AIF, in the brainstem.Conclusions: SP could decrease hearing degeneration in SAMP8 mice possibly via reducing caspase-independent apoptosis signal pathway in the cochlea and brainstem.

2019 ◽  
pp. 014556131987431
Author(s):  
Burak Mustafa Taş ◽  
Gökçe Şimşek ◽  
Musa Azman ◽  
Rahmi Kılıç

Ototoxicity is the general name of cochlear and vestibular organ injury resulting from encountering various therapeutic agents and chemical substances. Cisplatin is commonly used in the treatment of many cancers. In this study, the efficacy of intratympanic steroids was compared for preventing cisplatin ototoxicity. In this study, 32 (64 ears) rats were used by separating into 4 groups. Cisplatin was administered intraperitoneally to the first group (n = 8). Methylprednisolone and then cisplatin were administered intratympanically to the second group (n = 8). On the third group (n = 8), dexamethasone and then cisplatin were administered intratympanically. To the fourth group (n = 8), 0.9% NaCl and then cisplatin were given intratympanically. Otoacoustic emission (OAE) measurements and auditory brainstem responses (ABRs) tests were performed on all groups before and 72 hours after the procedure. Pretreatment of ABR-IV values were 4.29 ± 0.19 milliseconds in group 2 and 4.27 ± 0.16 milliseconds in group 3, whereas posttreatment ABR-IV values were 4.95 ± 0.35 milliseconds in group 2 and 4.65 ± 0.26 milliseconds in group 3. The ABR-IV values were measured significantly shorter in the rats given dexamethasone and methylprednisolone, according to control and cisplatin groups ( P < .001). Pretreatment of ABR I-IV interval values were 2.98 ± 0.34 milliseconds and 3.03 ± 0.42 milliseconds in group 1 and group 4, respectively, and ABR I-IV interval values in group 1 and group 4 posttreatment were 3.49 ± 0.39 milliseconds and 3.5 ± 0.39 milliseconds in group 1 and group 4, respectively. Auditory brainstem responses I-IV interval was significantly longer in the cisplatin and control group than in the rats given dexamethasone and methylprednisolone ( P < .001). After cisplatin treatment, OAE amplitudes decreased significantly in group 1 and group 4 for all frequencies, while OAE values were protected in methylprednisolone and dexamethasone group ( P < .001). In conclusion, it has been shown that both agents have protective effects on cisplatin ototoxicity, with dexamethasone slightly more than methylprednisolone.


2016 ◽  
Vol 21 (4) ◽  
pp. 254-260
Author(s):  
Selin Ünsaler ◽  
Bora Başaran ◽  
Şule Öztürk Sarı ◽  
Eyüp Kara ◽  
Kemal Değer ◽  
...  

Objectives: To investigate the efficacy of chitosan-dextran hydrogel (CDH) in preventing postoperative adhesions between the tympanic membrane (TM) and intratympanic structures, and to evaluate its ototoxicity in an animal study. Methods: In the first step, ototoxicity was evaluated with 7 male albino guinea pigs (GPs) via auditory brainstem responses (ABR) before and 4 weeks after unilateral intratympanic injection of CDH and saline solution contralaterally. In the second step, 12 GPs underwent bilateral ear surgery. The middle ear (ME) mucosa was abraded, and the cavity was filled with CDH on one side and packed with Gelfoam on the contralateral side. A control group of 6 GPs underwent the same procedure except that no material was applied in the ME. The animals were euthanized at the end of the 7th week, and otomicroscopic findings were noted and the temporal bones harvested for the histologic examination. The findings were scored and compared. Results: There was no statistically significant difference between the pre- and postoperative ABR thresholds. In the otomicroscopic findings, the most prominent difference between the two groups was the presence of retraction of the TM in the Gelfoam group. The histopathologic findings revealed a higher degree of inflammation in the Gelfoam group compared with the CDH group. Conclusion: This study demonstrated that CDH has no ototoxic effects in GPs. Its use as an ME packing material revealed significantly less TM retraction and inflammatory reaction compared with Gelfoam.


2021 ◽  
Vol 71 (1) ◽  
Author(s):  
Qin Wang ◽  
Wei Li ◽  
Cuiyun Cai ◽  
Peng Hu ◽  
Ruosha Lai

AbstractDamage to the cochlear sensory epithelium is a key contributor to noise-induced sensorineural hearing loss (SNHL). KCNQ4 plays an important role in the cochlear potassium circulation and outer hair cells survival. As miR-153 can target and regulate KCNQ4, we sought to study the role of miR-153 in SNHL. 12-week-old male CBA/J mice were exposed to 2–20 kHz broadband noise at 96 dB SPL to induce temporary threshold shifts and 101 dB SPL to induce permanent threshold shifts. Hearing loss was determined by auditory brainstem responses (ABR). Relative expression of miR-153 and KCNQ4 in mice cochlea were determined by Real-Time quantitative PCR. miR-153 mimics were co-transfected with wild type or mutated KCNQ4 into HEK293 cells. Luciferase reporter assay was used to validate the binding between miR-153 and KCNQ4. AAV-sp-153 was constructed and administrated intra-peritoneally 24- and 2-h prior and immediately after noise exposure to knockdown miR-153. The KCNQ4 is mainly expressed in outer hair cells (OHCs). We showed that the expression of KCNQ4 in mice cochlea was reduced and miR-153 expression was significantly increased after noise exposure compared to control. miR-153 bound to 3′UTR of KNCQ4, and the knockdown of miR-153 with the AAV-sp-153 administration restored KCNQ4 mRNA and protein expression. In addition, the knockdown of miR-153 reduced ABR threshold shifts at 8, 16, and 32 kHz after permanent threshold shifts (PTS) noise exposure. Correspondingly, OHC losses were attenuated with inhibition of miR-153. This study demonstrates that miR-153 inhibition significantly restores KNCQ4 in cochlea after noise exposure, which attenuates SNHL. Our study provides a new potential therapeutic target in the prevention and treatment of SNHL.


2002 ◽  
Vol 13 (07) ◽  
pp. 367-382 ◽  
Author(s):  
Suzanne C. Purdy ◽  
Andrea S. Kelly ◽  
Merren G. Davies

Auditory evoked potentials (AEPs) and behavioral tests were used to evaluate auditory processing in 10 children aged 7 to 11 years who were diagnosed as learning disabled (LD). AEPs included auditory brainstem responses (ABRs), middle latency responses (MLRs), and late cortical responses (P1, N1, P2, P3). Late cortical responses were recorded using an active listening oddball procedure. Auditory processing disorders were suspected in the LD children after a psychologist found phonologic processing and auditory memory problems. A control group of 10 age- and gender-matched children with no hearing or reported learning difficulties was also tested. Teacher ratings of classroom listening and SCAN Competing Words and Staggered Spondaic Word scores were poorer in the LD children. There were minor ABR latency differences between the two groups. Wave Na of the MLR was later and Nb was smaller in the LD group. The main differences in cortical responses were that P1 was earlier and P3 was later and smaller in the LD group.


PEDIATRICS ◽  
1985 ◽  
Vol 75 (4) ◽  
pp. 703-708 ◽  
Author(s):  
Hajime Nakamura ◽  
Satoshi Takada ◽  
Roberto Shimabuku ◽  
Masafumi Matsuo ◽  
Tamotsu Matsuo ◽  
...  

To assess early bilirubin toxicity, a study was made of auditory brainstem responses in relation to total bilirubin levels as well as unbound bilirubin levels in 56 hyperbilirubinemic infants (total bilirubin ≥15.0 mg/dL) and 24 infants who did not have jaundice. The latencies of wave I at 85 dB HL (hearing level) in hyperbilirubinemic infants were significantly greater than those in the control group. The latencies of wave I and V in hyperbilirubinemic infants with unbound bilirubin levels ≥1.0 µg/dL (group C) were greater than those in the control group and in the hyperbilirubinemic infants with unbound bilirubin levels &lt;0.5 µg/dL (group A) and with unbound bilirubin levels &lt;1.0 µg/dL (group B). There were no significant differences of the wave I-V interpeak latency between the control infants and the hyperbilirubinemic infants. Thirty of the 80 infants showed prolonged peak latencies (greater than the mean ± 2 SD for the control infants) of wave I and/or V in one or both ears. The incidences of the prolonged peak latencies in group B (42%) and group C (89%) were significantly greater than that in the control group (12%). The serial determinations of auditory brainstem responses in infants treated with exchange transfusions revealed that the prolonged peak latencies before exchange transfusion improved at 48 and 96 hours after the procedure for wave I, and at 24, 48, and 96 hours after the procedure for wave V. The interpeak latency of wave I-V did not change with exchange transfusion. These results suggest that the auditory nerve is reversibly damaged in the infants with hyperbilirubinemia, and, in particular, the abnormal auditory brainstem response recordings are more closely related to the unbound bilirubin level than the total bilirubin level.


2021 ◽  
pp. 1-13
Author(s):  
Selis Gulseven Guven ◽  
Onur Ersoy ◽  
Ruhan Deniz Topuz ◽  
Erdoğan Bulut ◽  
Gulnur Kizilay ◽  
...  

<b><i>Introduction:</i></b> The effect of orally consumed monosodium glutamate (MSG), which is a common additive in the food industry, on the cochlea has not been investigated. The present study aimed to investigate the possible cochleotoxic effects of oral MSG in guinea pigs using electrophysiological, biochemical, and histopathological methods. <b><i>Methods:</i></b> Thirty guinea pigs were equally divided into control and intervention groups (MSG 100 mg/kg/day; MSG 300 mg/kg/day). At 1 month, 5 guinea pigs from each group were sacrificed; the rest were observed for another month. Electrophysiological measurements (distortion product otoacoustic emission [DPOAE] and auditory brainstem response [ABR]), glutamate levels in the perilymph and blood samples, and histopathological examinations were evaluated at 1 and 2 months. <b><i>Results:</i></b> Change in signal-to-noise ratio at 2 months was significantly different in the MSG 300 group at 0.75 kHz and 2 kHz (<i>p</i> = 0.013 and <i>p</i> = 0.044, respectively). There was no statistically significant difference in ABR wave latencies of the guinea pigs given MSG compared to the control group after 1 and 2 months; an increase was noted in ABR thresholds, although the difference was not statistically significant. In the MSG groups, moderate-to-severe degeneration and cell loss in outer hair cells, support cells, and spiral ganglia, lateral surface junction irregularities, adhesions in stereocilia, and partial loss of outer hair cell stereocilia were noted. <b><i>Conclusion:</i></b> MSG, administered in guinea pigs at a commonly utilized quantity and route of administration in humans, may be cochleotoxic.


1983 ◽  
Vol 92 (3) ◽  
pp. 249-253 ◽  
Author(s):  
Richard C. Folsom ◽  
Bruce A. Weber ◽  
Gary Thompson

Auditory brainstem responses were recorded from an experimental group of 15 children with early histories of recurrent middle ear disease for the purpose of examining the effects of reduced auditory input on auditory brainstem function. The responses from these children were analyzed in terms of absolute latencies, interwave latencies and latency shifts across sensation level. Comparisons were made to a control group of children with no history of middle ear disease. Results indicated significant differences between the groups. The experimental group demonstrated greater absolute latencies for waves III and V as well as greater interwave latencies. These findings support the interpretation of an association between early recurrent middle ear disease and brainstem function.


2020 ◽  
Vol 79 (OCE2) ◽  
Author(s):  
Carmen Morais-Moreno ◽  
María del Pilar Garzón-Riveros ◽  
Silvia Murillo-Cuesta ◽  
Lourdes Rodríguez-de la Rosa ◽  
Ana Montero ◽  
...  

AbstractIntroductionAge-related hearing loss (ARHL) is a sensory impairment, with a dramatic increase in its incidence, which is caused by genetic and environmental factors such as noise and ototoxic drugs. Recent studies correlated ARHL to elevated plasma homocysteine (Hcy) by folate deficiency, suggesting that reduction of Hcy levels by folate supplementation could potentially ameliorate ARHL.Hyperhomocysteinemia (HHcy), a status that contributes to ARHL, may also arise from malfunction of Hcy remethylation by betaine homocysteine S-methyltransferases (BHMTs) and methionine synthase in the methionine cycle. The expression and/or activity of these enzymes may be altered by ototoxic drugs, including paracetamol (APAP).ObjectiveTo determine the effect of APAP in cochlear morphology and function of control and Bhmt-/- mice, and to analyze putative preventive effects of folic acid (FA) supplementation.Materials and MethodsTwo-month-old Bhmt-/- mice (n = 47), with greater dependence on folate metabolism for Hcy remethylation, and Bhmt + / + mice (n = 42) were fed control or FA supplemented diets for 30 days. The last day APAP (250 mg/kg) or placebo were injected intraperitoneally.Hearing was evaluated by recording auditory brainstem responses (ABR) at the beginning of the experiment and after treatments. Picrosirius red staining was used for evaluation of the cochlear lateral wall cytoarchitecture. Plasma and hepatic metabolite levels were determined by HPLC or on Spinlab 100® autoanalyzer.ResultsLoss of Bhmt expression induced HHcy, but an impact on hearing acuity was not observed. Acute APAP administration did not induce ABR threshold shifts. However, following ototoxic treatment, changes of 5–17% in the areas of the stria vascularis and spiral ligament were detected between Bhmt-/- mice under different dietary treatments; cochlear structures of Bhmt-/- mice receiving APAP plus FA supplementation resemble those of the control group. APAP increases susceptibility to ototoxic damage in the presence of HHcy.DiscussionBHMT plays a central role in cochlear methionine metabolism. FA supplementation modulates Hcy levels, contributing to a proper remethylation status that prevents ARHL.


2005 ◽  
Vol 48 (1) ◽  
pp. 189-203 ◽  
Author(s):  
Jeffrey A. Marler ◽  
Craig A. Champlin

The purpose of this study was to examine the possible contribution of sensory mechanisms to an auditory processing deficit shown by some children with language-learning impairment (LLI). Auditory brainstem responses (ABRs) were measured from 2 groups of school-aged (8–10 years) children. One group consisted of 10 children with LLI, and the other group (control) consisted of 10 children with normally developing language. The ABR was elicited with a brief tone burst presented either alone (no-masking condition) or immediately followed by a longer duration noise burst (backward-masking condition). The primary dependent variable was the latency of wave V of the ABR. The mean latencies were not significantly different for the 2 groups in the no-masking condition. However, in the backward-masking condition, the mean latency for the LLI group was significantly increased relative to the mean latency for the control group. Thus, the presence of successive sounds delay the neural response in children with LLI. The explanation for this delay at the level of the brainstem is not known, but it may be due to disruption of synchrony, activation of alternate (less direct) pathways, increased inhibition, or some combination of these (or other) factors.


Sign in / Sign up

Export Citation Format

Share Document