PACAP ameliorates oxidative stress in the chicken inner ear: an in vitro study.
Pituitary adenylate cyclase activating polypeptide (PACAP) is a pleiotropic and multifunctional neuropeptide. Numerous studies prove that PACAP has neuroprotective effects in diverse neuronal systems in vitro and in vivo. The involvement of PACAP in visual and olfactory sensory processing has also been documented, but little is known about its effects in the auditory system. The presence of PACAP and its receptor, the specific PAC1 receptor, has been shown in the cochlea and in brain structures involved in auditory pathways. The aim of the present study was to investigate whether PACAP is protective in cochlear oxidative stress-induced cell death, which is known to play a role in several ototoxic insults. Chicken cochlear cells were exposed to 1mM H(2)O(2), which resulted in a marked reduction of cell viability and a parallel increase of apoptotic and necrotic cells assessed by MTT test, annexin V/propidium iodide flow cytometry and JC-1 apoptosis assay. Co-incubation with 100nM PACAP increased cell viability and reduced the percentage of apoptotic cells. Furthermore, oxidative stress increased the activation of caspase-3, while simultaneous PACAP treatment reduced it. In summary, our present results demonstrate that PACAP effectively protects cochlear cells against oxidative stress-induced apoptotic cell death.
Racz
Boglarka
B
Department of Biochemistry and Medical Chemistry, University of Pecs, Hungary.
Horvath
Gabriella
G
Reglodi
Dora
D
Gasz
Balazs
B
Kiss
Peter
P
Gallyas
Ferenc
F
Sumegi
Balazs
B
Toth
Gabor
G
Nemeth
Adrienne
A
Lubics
Andrea
A
Tamas
Andrea
A
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D053148:Caspase 3 / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002645:Chickens; D003051:Cochlea / Q000166:cytology / Q000187:drug effects*; D004789:Enzyme Activation / Q000187:drug effects; D005434:Flow Cytometry; D007150:Immunohistochemistry; D018384:Oxidative Stress / Q000187:drug effects*; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide / Q000494:pharmacology*; D015398:Signal Transduction
D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D053148:Caspase 3