These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Calpain inhibitors protect auditory sensory cells from hypoxia and neurotrophin-withdrawal induced apoptosis.
    Author: Cheng AG, Huang T, Stracher A, Kim A, Liu W, Malgrange B, Lefebvre PP, Schulman A, Van de Water TR.
    Journal: Brain Res; 1999 Dec 11; 850(1-2):234-43. PubMed ID: 10629769.
    Abstract:
    Inhibitors of calpain have been shown to protect nerve growth factor (NGF)-deprived ciliary ganglion neurons and hypoxic cortical neurons. Calpains have been identified in the cochlea and are active during ischemic injury. Since apoptosis can be initiated by loss of neurotrophic support, hypoxia, and ototoxins (e.g., cisplatin, CDDP), the role of calpain inhibitors under these conditions was examined in auditory hair cells and neurons. Dissociated spiral ganglion neuron (SGN) cell cultures and organ of Corti explants from P3 rats were used to test the efficacy of calpain inhibitors as otoprotective molecules. Our results indicate that calpain inhibitor I, calpain inhibitor II, and leupeptin all provided significant protection of SGNs against neurotrophin-withdrawal and hypoxia-induced apoptosis. The increase in neuronal survival ranged from 2.16 to 2.31 times greater than in untreated neurotrophin-withdrawn SGN cell cultures. BOC-Asp(Ome)-Fluoromethyl Ketone (B-D-FMK), a general caspase inhibitor, increased neuronal survival 2.16 times more. Neuronal survival rates were from 1.88 to 2.27 times greater than in untreated, hypoxic neurons and hair cell survival rates were from 1.98 to 2.03 times greater than untreated, hypoxic organ of Corti explants. However, protection of auditory hair cells and neurons from CDDP-induced damage (10 and 6 micrograms/ml, respectively) was limited with any of these calpain inhibitors. Apoptotic pathways initiated by neurotrophin-deprivation and ototoxic stress (e.g., CDDP) have been shown to be different. Our results agree with this finding, with neurotrophin-withdrawal and hypoxia, but not CDDP damage-induced apoptosis being calpain-dependent.
    [Abstract] [Full Text] [Related] [New Search]