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A protective mechanism against antibiotic-induced ototoxicity: role of prestin.

Yu L, Jiang XH, Zhou Z, Tsang LL, Yu MK, Chung YW, Zhang XH, Wang AM, Tang H, Chan HC - PLoS ONE (2011)

Bottom Line: Hearing loss or ototoxicity is one of the major side effects associated with the use of the antibiotics, particularly aminoglycosides (AGs), which are the most commonly used antibiotics worldwide.In the present study, we test the possibility that prestin, the motor protein specifically expressed in the basolateral membrane of outer hair cells (OHCs) in the cochlea with electromotility responsible for sound amplification, may be involved in the process of AG-induced apoptosis in OHCs.Our results from both mice model and cultured cell line indicate a previously unexpected role of prestin, in mediating antibiotic-induced apoptosis, the effect of which is associated with its anion-transporting capacity.

View Article: PubMed Central - PubMed

Affiliation: Epithelial Cells Biology Research Center, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, ShaTin, Hong Kong.

ABSTRACT
Hearing loss or ototoxicity is one of the major side effects associated with the use of the antibiotics, particularly aminoglycosides (AGs), which are the most commonly used antibiotics worldwide. However, the molecular and cellular events involved in the antibiotic-induced ototoxicity remains unclear. In the present study, we test the possibility that prestin, the motor protein specifically expressed in the basolateral membrane of outer hair cells (OHCs) in the cochlea with electromotility responsible for sound amplification, may be involved in the process of AG-induced apoptosis in OHCs. Our results from both mice model and cultured cell line indicate a previously unexpected role of prestin, in mediating antibiotic-induced apoptosis, the effect of which is associated with its anion-transporting capacity. The observed downregulation of prestin mRNA prior to detectable apoptosis in OHCs and hearing loss in the antibiotic-treated mice is interesting, which may serve as a protective mechanism against hearing loss induced by AGs in the early stage.

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Overexpression of prestin in CHO cells enhances kanamycin-induced apoptosis.pcDNA3.1(-)-prestin or control vector were transfected into CHO cells with lipofectamine as described in Materials and Methods and the cells were treated with 100 µM kanamycin for the time indicated. (A): immunofluorescence staining of prestin in CHO cells showing >90% of the cells expressing prestin. (B): Control and prestin transfected cells were treated with 100 µM kanamycin for 2 h, and analyzed by MTS assay as described in Materials and Methods. Y axis indicates the percentage of viable cells relative to untreated cells. *, p<0.05. (C): Quantification of TUNEL positive cells in control and prestin-transfected cells treated with 100 µM kanamycin for 2 h or 4 h. ***, p<0.01.
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pone-0017322-g003: Overexpression of prestin in CHO cells enhances kanamycin-induced apoptosis.pcDNA3.1(-)-prestin or control vector were transfected into CHO cells with lipofectamine as described in Materials and Methods and the cells were treated with 100 µM kanamycin for the time indicated. (A): immunofluorescence staining of prestin in CHO cells showing >90% of the cells expressing prestin. (B): Control and prestin transfected cells were treated with 100 µM kanamycin for 2 h, and analyzed by MTS assay as described in Materials and Methods. Y axis indicates the percentage of viable cells relative to untreated cells. *, p<0.05. (C): Quantification of TUNEL positive cells in control and prestin-transfected cells treated with 100 µM kanamycin for 2 h or 4 h. ***, p<0.01.

Mentions: Does prestin play a role in the kanamycin-induced apoptosis? If yes, through what mechanism? To answer these questions and taking into the consideration that very limited number of OHCs could be isolated from the cochlea, we transfected CHO cells, which do not express endogenous prestin, with prestin and compared their response to kanamycin to that in CHO cells transfected with empty vector. After transfection, over 90% of CHO cells expressed prestin, which was localized predominantly at the plasma membrane (Fig. 3A). MTS assay results showed that treatment with 100 µM Kanamycin for 2 h significantly decreased number of viable cells in prestin-expressing CHO cells compared with the vector control (Fig. 3B). Further TUNEL assay showed that while kanamycin did not induce significant apoptosis in control-vector transfected CHO cells, the forced expression of prestin significantly increased the number of apoptotic cells in kanamycin-treated CHO cells (Fig. 3C), indicating a predominant role of prestin in the kanamycin-induced apoptosis.


A protective mechanism against antibiotic-induced ototoxicity: role of prestin.

Yu L, Jiang XH, Zhou Z, Tsang LL, Yu MK, Chung YW, Zhang XH, Wang AM, Tang H, Chan HC - PLoS ONE (2011)

Overexpression of prestin in CHO cells enhances kanamycin-induced apoptosis.pcDNA3.1(-)-prestin or control vector were transfected into CHO cells with lipofectamine as described in Materials and Methods and the cells were treated with 100 µM kanamycin for the time indicated. (A): immunofluorescence staining of prestin in CHO cells showing >90% of the cells expressing prestin. (B): Control and prestin transfected cells were treated with 100 µM kanamycin for 2 h, and analyzed by MTS assay as described in Materials and Methods. Y axis indicates the percentage of viable cells relative to untreated cells. *, p<0.05. (C): Quantification of TUNEL positive cells in control and prestin-transfected cells treated with 100 µM kanamycin for 2 h or 4 h. ***, p<0.01.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3045444&req=5

pone-0017322-g003: Overexpression of prestin in CHO cells enhances kanamycin-induced apoptosis.pcDNA3.1(-)-prestin or control vector were transfected into CHO cells with lipofectamine as described in Materials and Methods and the cells were treated with 100 µM kanamycin for the time indicated. (A): immunofluorescence staining of prestin in CHO cells showing >90% of the cells expressing prestin. (B): Control and prestin transfected cells were treated with 100 µM kanamycin for 2 h, and analyzed by MTS assay as described in Materials and Methods. Y axis indicates the percentage of viable cells relative to untreated cells. *, p<0.05. (C): Quantification of TUNEL positive cells in control and prestin-transfected cells treated with 100 µM kanamycin for 2 h or 4 h. ***, p<0.01.
Mentions: Does prestin play a role in the kanamycin-induced apoptosis? If yes, through what mechanism? To answer these questions and taking into the consideration that very limited number of OHCs could be isolated from the cochlea, we transfected CHO cells, which do not express endogenous prestin, with prestin and compared their response to kanamycin to that in CHO cells transfected with empty vector. After transfection, over 90% of CHO cells expressed prestin, which was localized predominantly at the plasma membrane (Fig. 3A). MTS assay results showed that treatment with 100 µM Kanamycin for 2 h significantly decreased number of viable cells in prestin-expressing CHO cells compared with the vector control (Fig. 3B). Further TUNEL assay showed that while kanamycin did not induce significant apoptosis in control-vector transfected CHO cells, the forced expression of prestin significantly increased the number of apoptotic cells in kanamycin-treated CHO cells (Fig. 3C), indicating a predominant role of prestin in the kanamycin-induced apoptosis.

Bottom Line: Hearing loss or ototoxicity is one of the major side effects associated with the use of the antibiotics, particularly aminoglycosides (AGs), which are the most commonly used antibiotics worldwide.In the present study, we test the possibility that prestin, the motor protein specifically expressed in the basolateral membrane of outer hair cells (OHCs) in the cochlea with electromotility responsible for sound amplification, may be involved in the process of AG-induced apoptosis in OHCs.Our results from both mice model and cultured cell line indicate a previously unexpected role of prestin, in mediating antibiotic-induced apoptosis, the effect of which is associated with its anion-transporting capacity.

View Article: PubMed Central - PubMed

Affiliation: Epithelial Cells Biology Research Center, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, ShaTin, Hong Kong.

ABSTRACT
Hearing loss or ototoxicity is one of the major side effects associated with the use of the antibiotics, particularly aminoglycosides (AGs), which are the most commonly used antibiotics worldwide. However, the molecular and cellular events involved in the antibiotic-induced ototoxicity remains unclear. In the present study, we test the possibility that prestin, the motor protein specifically expressed in the basolateral membrane of outer hair cells (OHCs) in the cochlea with electromotility responsible for sound amplification, may be involved in the process of AG-induced apoptosis in OHCs. Our results from both mice model and cultured cell line indicate a previously unexpected role of prestin, in mediating antibiotic-induced apoptosis, the effect of which is associated with its anion-transporting capacity. The observed downregulation of prestin mRNA prior to detectable apoptosis in OHCs and hearing loss in the antibiotic-treated mice is interesting, which may serve as a protective mechanism against hearing loss induced by AGs in the early stage.

Show MeSH
Related in: MedlinePlus