Novel Peptide Vaccine GV1001 Rescues Hearing in Kanamycin/Furosemide-Treated Mice

Abstract

The cell-penetrating peptide GV1001 has been investigated as an anticancer agent and recently demonstrated anti-oxidant and anti-inflammatory effects. It has shown a protective effect on a kanamycin (KM)-induced ototoxicity mouse model. In the present study, we administered GV1001 at different time points after inducing hair cell damage, and examined if it rescues hair cell loss and restores hearing. A deaf mouse model was created by intraperitoneal injection of KM and furosemide. First, to test the early temporal change of hearing and extent of hair cell damage after KM and furosemide injection, hearing and outer hair cells (OHCs) morphology were evaluated on day 1, day 2 and day 3 after injection. In the second experiment, following KM and furosemide injection, GV1001, dexamethasone, or saline were given for three consecutive days at different time points: D0 group (days 0, 1, and 2), D1 group (days 1, 2, and 3), D3 group (days 3, 4, and 5) and D7 group (days 7, 8, and 9). The hearing thresholds were measured at 8, 16, and 32 kHz before ototoxic insult, and 7 days and 14 days after KM and furosemide injection. After 14 days, each turn of the cochlea was imaged to evaluate OHCs damage. GV1001-treated mice showed significantly less hearing loss and OHCs damage than the saline control group in the D0, D1 and D3 groups (p < 0.0167). However, there was no hearing restoration or intact hair cell in the D7 group. GV1001 protected against cochlear hair cell damage, and furthermore, delayed administration of GV1001 up to 3 days rescued hair cell damage and hearing loss in KM/furosemide-induced deaf mouse model.

Outcomes of Peptide Vaccine GV1001 Treatment in a Murine Model of Acute Noise-Induced Hearing Loss

“…The otoprotective effect of GV1001, as documented by reduction of hearing threshold shift and maintenance of hair cell framework against PTS-noise exposure, may be associated with the downregulation of excessive ROS and RNS expression. In accordance with this, GV1001 shows beneficial effects on kanamycin-induced ototoxicity, suggesting that its therapeutic action is associated with attenuations of oxidative stress conditions [12,13]. Considering that the ROS and RNS generation trigger inflammatory and cell stress or apoptotic pathways via ROS/RNS signaling cascades [6], GV1001 may not only directly scavenge free radical activity, but also indirectly downregulate inflammation and cell stress or apoptosis by lowering oxidative stress.…”

“…As described previously [12,13], we measured ABR thresholds using tone bursts (envelope, Blackman; duration, 1562 ms; stimulation rate, 21.1/s) delivered at 8, 16, and 32 kHz (SmartEP; Intelligent Hearing System; Miami, FL, USA) to the external auditory meatus via plastic earphones connected to an EC1 electrostatic speaker. ABR stimulus was presented in a closed field setting and both the ears tested separately.…”

“…The method used to determine the proportion of intact OHCs has previously been described [12,13]. Briefly, after mounting, immunolabeled samples were imaged using a Zeiss 710 confocal microscope at a uniform magnification of 63×.…”

“…GV1001, a novel cell-penetrating peptide (16-amino-acid sequence) derived from human telomerase reverse transcriptase, has been implicated to have anticancer, antioxidant, anti-inflammatory, and antiapoptotic effects in kidney; it prevents myocardial ischemia-reperfusion injury; stimulates neural stem cell; and is active against various cancer types [7][8][9][10][11]. Moreover, our previous studies revealed that GV1001 significantly attenuated hearing threshold shift and cochlear outer hair cell (OHC) damage in kanamycin-induced ototoxicity mouse model [12,13]. Given that antibiotics-induced ototoxicity has been associated with oxidative stress as a potential mechanism for damage [14], GV1001 may effectively attenuate kanamycin-induced ototoxicity toward sensory hair cells by downregulating ROS/RNS overproduction and their subsequent byproducts.…”

Contralateral spreading of substances following intratympanic nanoparticle-conjugated gentamicin injection in a rat model

“…As described in our previous report, after decapitation under anesthesia, the cochleae from both ears were immersion-fixed with 4% paraformaldehyde (pH 7.4) 26 . Via surface preparation, the membranous labyrinth was dissected under a microscope and fixed with 4% paraformaldehyde.…”