D'Avanzo, Carla (2011) A hyperfunctional NCX3-proteolytic fragment generated by Abeta1-42 delays caspase-12 activation and neuronal death in mice. [Tesi di dottorato] (Unpublished)

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Item Type: Tesi di dottorato
Language: English
Title: A hyperfunctional NCX3-proteolytic fragment generated by Abeta1-42 delays caspase-12 activation and neuronal death in mice
Creators:
CreatorsEmail
D'Avanzo, Carlacarla.davanzo@unina.it
Date: 30 November 2011
Number of Pages: 76
Institution: Università degli Studi di Napoli Federico II
Department: Neuroscienze
Doctoral School: Medicina molecolare
PHD name: Neuroscienze
PHD cycle: 24
PHD Coordinator:
nameemail
Annunziato, Luciolannunzi@unina.it
Tutor:
nameemail
Pannaccione, Annapannacio@unina.it
Date: 30 November 2011
Number of Pages: 76
Uncontrolled Keywords: NCX3, Abeta1-42
MIUR S.S.D.: Area 05 - Scienze biologiche > BIO/14 - Farmacologia
Date Deposited: 07 Dec 2011 10:49
Last Modified: 30 Apr 2014 19:48
URI: http://www.fedoa.unina.it/id/eprint/8751

Abstract

Abeta1-42, the peptide involved in the pathogenesis of Alzheimer’s disease, causes a dysregulation of intracellular Ca2+ homeostasis. However, all the mechanisms involved in this process remain unknown. Here, we reported that A1-42 induced an increase in NCX currents (INCX) in the reverse mode of operation that was completely prevented by silencing or knocking-out the ncx3 gene. Moreover, a calpain-dependent cleavage of NCX3 was essential for the Abeta1-42-dependent INCX increase. Indeed, the removal of the calpain recognition-site abolished the Abeta1-42-stimulatory effect on INCX. Consistently, the N-terminal proteolytic fragment of NCX3 generated INCX comparable to those recorded after Abeta1-42 exposure. On the other hand, Abeta1-42 exposure increased Ca2+ refilling into endoplasmic reticulum (ER), an event that was prevented in neurons silenced or knocked-out for NCX3. This latter finding suggested that NCX3 was involved in ER Ca2+-refilling stimulated by Abeta1-42. Finally, NCX3 silencing caused an earlier activation of Abeta1-42-induced caspase-12. Indeed, in NCX3 silenced neurons, Abeta1-42 exposure hastened caspase-dependent apoptosis, thus reinforcing neuronal cell death. Altogether, these results suggested that the NCX3 hyperfunctional proteolytic fragment, produced by Abeta1-42-induced calpain activation, contributed to neuronal Ca2+-refilling into ER. This event exerted a neuroprotective effect during Abeta1-42 insult by delaying caspase-12 activation, apoptosis, and neuronal death.

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