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. 2019 Sep 20;20(19):4675.
doi: 10.3390/ijms20194675.

Hyperbaric Oxygen Treatment Ameliorates Hearing Loss and Auditory Cortex Injury in Noise Exposed Mice by Repressing Local Ceramide Accumulation

Yu-Ting Su  1 , Yi-Bin Guo  2 , Yao-Ping Cheng  3 , Xi Zhang  4 , Xiao-Ping Xie  5 , Yao-Ming Chang  6 , Jun-Xiang Bao  7
Affiliations

Hyperbaric Oxygen Treatment Ameliorates Hearing Loss and Auditory Cortex Injury in Noise Exposed Mice by Repressing Local Ceramide Accumulation

Yu-Ting Su et al. Int J Mol Sci. .

Abstract

Noise-induced hearing loss (NIHL) relates closely to auditory cortex (AC) injury, so countermeasures aiming at the AC recovery would be of benefit. In this work, the effect of hyperbaric oxygen treatment on NIHL was elucidated, which was imposed on mice before (HBOP), during (HBOD) or after (HBOA) noise exposure. Morphology of neurons was assayed by hematoxylin-eosin or Nissl staining. Ceramide (Cer) level was measured through immunohistochemistry analysis. Apoptotic neurons were counted using transferase-mediated dUTP nick end labeling (TUNEL) staining. We demonstrated that the intense, broad band noise raised the threshold of auditory brainstem response, evoked neuronal degeneration or apoptosis and triggered the Cer accumulation in AC, all of which were restored significantly by HBOP, but not HBOD or HBOA. Cer over-generation reversed the advantages of HBOP significantly, while its curtailment recapitulated the effect. Next, noise exposure raised the superoxide or malondialdehyde (MDA) production which was blocked by HBOP or Cer repression. Oxidative control not only attenuated the hearing loss or neurodegeneration but, in turn, reduced the Cer formation significantly. In summary, mutual regulation between Cer and oxidative stress underlies the HBOP's curative effect on hearing loss and neuronal damage in noise-exposed mice.

Keywords: acid ceramidase; acid sphingomyelinase; ceramide; hearing loss; hyperbaric oxygen therapy; noise; oxidative stress.

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Conflict of interest statement

The authors declare no conflicts of interest.

Figures

Figure 1
Figure 1
Auditory brainstem response (ABR) threshold to sound with frequency of 2k, 4k, 6k, or 8k Hz (a), original images (b) and summarized data (c) of hematoxylin and eosin (HE) or Nissl staining in auditory cortex (AC) of mice in Con, Con + HBO, Noise, Noise untreated, HBOP, HBOD, and HBOA. The arrows indicate the vacuole formation and karyopyknosis in the neuron, magnification ×400, scale bar = 50 μm. Data is shown as means ± SD, n = 5 in ABR, n = 3 in HE or Nissl staining, **P < 0.01, *P < 0.05 vs. Con, ##P < 0.01, #P < 0.05 vs. Noise, $P < 0.05 vs. Noise untreated. All individual data points were shown in the figure using different shapes, • for Con group, ■ for Con+HBO group, ▲ for Noise group, ▼ for Noise untreated group, ⬥ for Noise+HBOP group, ◯ for Noise+HBOD group, □ for Noise+HBOA group.
Figure 2
Figure 2
Original images (a,c) and summarized data (b,c) showing neuronal apoptosis, protein expression of B cell lymphoma-2 (bcl-2) and bcl-2 associated X protein (bax) in auditory cortex (AC) of mice in Con or Noise group with or without hyperbaric oxygen treatment detected by TdT-mediated dUTP nick-end labeling (TUNEL) (a), immunohistochemistry staining (IHC) (a) or western blotting (c) assay. The arrows indicate apoptotic neurons, in TUNEL, magnification ×200, in IHC, magnification ×400, scale bar = 50 μm. Data are shown as means ± SD, n = 3 in IHC or TUNEL, n = 6 in western blot assay, **P < 0.01, *P < 0.05 vs. Con, ##P < 0.01, #P < 0.05 vs. Noise. All individual data points were shown in the figure using different shapes, • for Con group, ■ for Con+HBO group, ▲ for Noise group, ⬥ for Noise+HBOP group.
Figure 3
Figure 3
Representative images (a) and summarized data (b) showing the content of ceramide (Cer), acid sphingomyelinase (ASM) or acid ceramidase (ACDase) in auditory cortex of mice from Con or Noise group with or without hyperbaric oxygen treatment detected by IHC (a) and western blot (c) assay. Magnification ×400, scale bar = 50 μm. Data are shown as means ± SD, n = 3 in IHC, n = 6 in western blot, **P < 0.01, *P < 0.05 vs Con, ##P < 0.01, #P < 0.05 vs Noise. All individual data points were shown. All individual data points were shown in the figure using different shapes, • for Con group, ■ for Con+HBO group, ▲ for Noise group, ⬥ for Noise+HBOP group.
Figure 4
Figure 4
Representative images (a) and summarized data (b) of HE or Nissl staining in auditory cortex of mice in Noise or HBOP group treated with Veh, Car or DOX. The arrows indicate the vacuole formation and karyopyknosis in the neuron. Original images (c,e) and analyzed data (d,e) showing neuronal apoptosis, protein expression of bax and bcl-2 in auditory cortex of mice in Noise or HBOP group treated with Veh, Car, or DOX detected by TUNEL (c), IHC (c), or western blotting (e) assay. The arrows indicate apoptotic neurons, in TUNEL magnification ×200, in IHC, magnification ×400, scale bar = 50μm. Data are shown as means ± SD, n = 3 in HE, Nissl, IHC or TUNEL, n = 6 in western blot assay, ##P < 0.01, #P < 0.05 vs Noise, &P < 0.05 vs HBOP. All individual data points were shown in the figure using different shapes, ▲ for Noise group, ◯ for Noise+Car group, ∆ for Noise+DOX group, ⬥ for Noise+HBOP group, ◓ for Noise+HBOP+Car group, ◭ for Noise+HBOP+DOX group.
Figure 5
Figure 5
Summarized data showing malonaldehyde (MDA) content (a) and superoxide dismutase (SOD) activity (b), original micrographs and analyzed data (c) on superoxide-sensitive dihydroethidium (DHE) fluorescence in auditory cortex of mice from Noise or HBOP group treated with Veh, Car, or DOX detected by colorimetric (a,b) or fluorescence staining (c) assay. Magnification ×400, scale bar = 50 μm. Data are shown as means ± SD, n = 6 in colorimetric assay, n = 3 in fluorescence staining, ##P < 0.01, #P < 0.05 vs Noise, &P < 0.05 vs. HBOP. All individual data points were shown in the figure using different shapes, ▲ for Noise group, ◯ for Noise+Car group, ∆ for Noise+DOX group, ⬥ for Noise+HBOP group, ◓ for Noise+HBOP+Car group, ◭ for Noise+HBOP+DOX group.
Figure 6
Figure 6
ABR threshold to sound with frequency of 2k, 4k, 6k, or 8k Hz (a), original images (b), and summarized data (c) of HE or Nissl staining in AC of mice in Con + Veh, Noise + Veh, Noise + Vc, Noise + HBOP + Veh, or Noise + HBOP + Vc group. The arrows indicate the vacuole formation and karyopyknosis in the neuron. Original images (d,f) and summarized data (e,g) showing neuronal apoptosis, bax, and bcl-2 in AC of mice in Con, Noise, and Noise + HBOP group treated with Veh or Vc detected by TUNEL (d), IHC (d), or western blotting (f) assay. The arrows indicate apoptotic neurons, magnification ×200, in HE, Nissl or IHC, magnification ×400, scale bar = 50 μm. Data are shown as means ± SD, n = 3 in HE, Nissl, IHC or TUNEL, n = 6 in western blotting assay, **P < 0.01, *P < 0.05 vs Con, ##P < 0.01, #P < 0.05 vs Noise. All individual data points were shown in the figure using different shapes, • for Con group, ▲ for Noise group, ⬥ for Noise+HBOP group, ⬒ for Noise+Vc group, ◧ for Noise+HBOP+Vc group.
Figure 7
Figure 7
Representative images and summarized data showing content of Cer (a,b), ASM (a–c) or ACDase (a–c) in AC of mice from Con + Veh, Noise + Veh, Noise + Vc, Noise + HBOP + Veh, or Noise + HBOP + Vc group detected by IHC (a) or western blot (c) assay. Magnification ×400, scale bar = 50 μm. Data are shown as means ± SD, n = 3 in IHC, n = 6 in western blot, *P < 0.05 vs. Con, #P < 0.05 vs Noise. All individual data points were shown in the figure using different shapes, • for Con group, ▲ for Noise group, ⬥ for Noise+HBOP group, ⬒ for Noise+Vc group, ◧ for Noise+HBOP+Vc group.
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References

    1. Basta D., Tzschentke B., Ernst A. Noise-induced cell death in the mouse medial geniculate body and primary auditory cortex. Neurosci. Lett. 2005;381:199–204. doi: 10.1016/j.neulet.2005.02.034. - DOI - PubMed
    1. Coordes A., Groschel M., Ernst A., Basta D. Apoptotic cascades in the central auditory pathway after noise exposure. J. Neurotrauma. 2012;29:1249–1254. doi: 10.1089/neu.2011.1769. - DOI - PubMed
    1. Su Y.T., Meng X.X., Zhang X., Guo Y.B., Zhang H.J., Cheng Y.P., Xie X.P., Chang Y.M., Bao J.X. Doxepin Mitigates Noise-induced Neuronal Damage in Primary Auditory Cortex of Mice via Suppression of Acid Sphingomyelinase/Ceramide Pathway. Anat. Rec. 2017;300:2220–2232. doi: 10.1002/ar.23677. - DOI - PubMed
    1. Frohlich F., Ernst A., Strubing I., Basta D., Groschel M. Apoptotic mechanisms after repeated noise trauma in the mouse medial geniculate body and primary auditory cortex. Exp. Brain Res. 2017;235:3673–3682. doi: 10.1007/s00221-017-5091-4. - DOI - PubMed
    1. Thom S.R. Hyperbaric oxygen: Its mechanisms and efficacy. Plast. Reconstr. Surg. 2011;127(Suppl. 1):131S–141S. doi: 10.1097/PRS.0b013e3181fbe2bf. - DOI - PMC - PubMed