Guanylyl Cyclase A/cGMP Signaling Slows Hidden, Age- and Acoustic Trauma-Induced Hearing Loss.

Abstract

In the inner ear, cyclic guanosine monophosphate (cGMP) signaling has been described as facilitating otoprotection, which was previously observed through elevated cGMP levels achieved by phosphodiesterase 5 inhibition. However, to date, the upstream guanylyl cyclase (GC) subtype eliciting cGMP production is unknown. Here, we show that mice with a genetic disruption of the gene encoding the cGMP generator GC-A, the receptor for atrial and B-type natriuretic peptides, display a greater vulnerability of hair cells to hidden hearing loss and noise- and age-dependent hearing loss. This vulnerability was associated with GC-A expression in spiral ganglia and outer hair cells (OHCs) but not in inner hair cells (IHCs). GC-A knockout mice exhibited elevated hearing thresholds, most pronounced for the detection of high-frequency tones. Deficits in OHC input-output functions in high-frequency regions were already present in young GC-A-deficient mice, with no signs of an accelerated progression of age-related hearing loss or higher vulnerability to acoustic trauma. OHCs in these frequency regions in young GC-A knockout mice exhibited diminished levels of KCNQ4 expression, which is the dominant K+ channel in OHCs, and decreased activation of poly (ADP-ribose) polymerase-1, an enzyme involved in DNA repair. Further, GC-A knockout mice had IHC synapse impairments and reduced amplitudes of auditory brainstem responses that progressed with age and with acoustic trauma, in contrast to OHCs, when compared to GC-A wild-type littermates. We conclude that GC-A/cGMP-dependent signaling pathways have otoprotective functions and GC-A gene disruption differentially contributes to hair-cell damage in a healthy, aged, or injured system. Thus, augmentation of natriuretic peptide GC-A signaling likely has potential to overcome hidden and noise-induced hearing loss, as well as presbycusis.

• Authors: Philine Marchetta, Dorit Möhrle, Philipp Eckert, Katrin Reimann, Steffen Wolter, Arianna Tolone, Isabelle Lang, Markus Wolters, Robert Feil, Jutta Engel, François Paquet-Durand, Michaela Kuhn, Marlies Knipper, Lukas Rüttiger
• Journal: Frontiers in aging neuroscience (Front Aging Neurosci) Vol. 12 Pg. 83 ( 2020) ISSN: 1663-4365 [Print] Switzerland
• PMID: 32327991 (Publication Type: Journal Article)
• Copyright: Copyright © 2020 Marchetta, Möhrle, Eckert, Reimann, Wolter, Tolone, Lang, Wolters, Feil, Engel, Paquet-Durand, Kuhn, Knipper and Rüttiger.