The neuroprotective mechanism of DREAM via ERAD pathway in dihydroxyphenylglycine preconditioned acute ischemic stroke rats / Nik Nasihah Nik Ramli

Neuroprotective strategies are required to complement the available medical treatments in order to enhance the brain endogenous protective mechanisms and cushion the effect of stroke injury. Pharmacological preconditioning is an avenue of preventative medication anticipated to be highly effective in...

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Main Author:	Nik Ramli, Nik Nasihah
Format:	Thesis
Language:	English
Published:	2016
Subjects:	Neuroprotective agents Central nervous system
Online Access:	https://ir.uitm.edu.my/id/eprint/62457/1/62457.pdf
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spelling	my-uitm-ir.624572022-06-28T09:16:54Z The neuroprotective mechanism of DREAM via ERAD pathway in dihydroxyphenylglycine preconditioned acute ischemic stroke rats / Nik Nasihah Nik Ramli 2016-12 Nik Ramli, Nik Nasihah Neuroprotective agents Central nervous system Neuroprotective strategies are required to complement the available medical treatments in order to enhance the brain endogenous protective mechanisms and cushion the effect of stroke injury. Pharmacological preconditioning is an avenue of preventative medication anticipated to be highly effective in protecting and reducing the ischemic induced neuronal damage. Recently, in vitro preconditioning studies have shown that prior activation of group I metabotropic receptor (mGluR) with its specific agonist (S)3,5-dihydroxyphenylglycine ((S)-3,5-DHPG) elicits neuroprotection against excitotoxicity. Furthermore, the activation of group I mGluR regulates the expression of DREAM. DREAM protein regulates transcription of various genes including edem1 which is a component protein of ER-associated degradation pathway (ERAD). This study elucidates the neuroprotective effect of group I mGluR agonist preconditioning, (S)-3,5-DHPG via DREAM and ERAD in acute ischemic stroke rats. One, 10 or 100 μM (S)-3,5-DHPG was administered intrathecally to 6 adult male Sprague Dawley rats 2 hours prior to the middle cerebral artery occlusion. After 24 hours, the modified neurological severity score (mNSS) and grid walking test were assessed. The rats were sacrificed and the infarct brain volumes were estimated by 2,3,5-triphenyltetrazolium chloride staining. The serum level of neuron-specific enolase (NSE) and brain tissue level of Bip/GRP78 ER stress marker were assessed by ELISA assays. The ischemic penumbra tissue surrounding the ischemic core infarct was dissected and the cytoplasmic and nuclear proteins as well as the total RNA were extracted. The protein levels of nuclear and cytoplasmic DREAM, as well as EDEM1, SEC61α and VCP were analysed by Western blot. The expression of dream and edem1 genes were analysed by qRT-PCR. Finally, the level of protein degradation activity in the ischemic penumbra tissue was determined by the 20S proteasomal assay. One or 10 μM of (S)-3,5-DHPG preconditioning in stroke rats has significantly improved the neurological functions and reduced the brain infarction as well as the NSE level. The DREAM protein has significantly increased in the nuclear compartment after 2 hours of 1 μM (S)-3,5-DHPG administration and in the cytoplasmic compartment after 24 hours of 100 μM (S)-3,5DHPG administration. Similarly, 1 μM (S)-3,5-DHPG preconditioning has significantly reduced the levels of Bip/GRP78 ER stress marker, DREAM and ERAD proteins as well as proteasomal degradation activity after 24 hours of an ischemic stroke. The expression of dream and edem1 gene were decreased in 1 μM (S)-3,5DHPG preconditioning compared to non-preconditioning ischemic stroke rats. In conclusion, the 1 and 10 μM of (S)-3,5-DHPG preconditioning enhanced the endogenous protective mechanism via promoting the nuclear DREAM protein to regulate the expression of EDEM1 and ERAD activities in order to alleviate subsequent ischemic injury in the brain whereas 100 μM of (S)-3,5-DHPG preconditioning exacerbated the ischemic injury. 2016-12 Thesis https://ir.uitm.edu.my/id/eprint/62457/ https://ir.uitm.edu.my/id/eprint/62457/1/62457.pdf text en public phd doctoral Universiti Teknologi MARA (Kampus Sg. Buloh) Faculty of Medicine Siran, Rosfaiizah
institution	Universiti Teknologi MARA
collection	UiTM Institutional Repository
language	English
advisor	Siran, Rosfaiizah
topic	Neuroprotective agents Central nervous system
spellingShingle	Neuroprotective agents Central nervous system Nik Ramli, Nik Nasihah The neuroprotective mechanism of DREAM via ERAD pathway in dihydroxyphenylglycine preconditioned acute ischemic stroke rats / Nik Nasihah Nik Ramli
description	Neuroprotective strategies are required to complement the available medical treatments in order to enhance the brain endogenous protective mechanisms and cushion the effect of stroke injury. Pharmacological preconditioning is an avenue of preventative medication anticipated to be highly effective in protecting and reducing the ischemic induced neuronal damage. Recently, in vitro preconditioning studies have shown that prior activation of group I metabotropic receptor (mGluR) with its specific agonist (S)3,5-dihydroxyphenylglycine ((S)-3,5-DHPG) elicits neuroprotection against excitotoxicity. Furthermore, the activation of group I mGluR regulates the expression of DREAM. DREAM protein regulates transcription of various genes including edem1 which is a component protein of ER-associated degradation pathway (ERAD). This study elucidates the neuroprotective effect of group I mGluR agonist preconditioning, (S)-3,5-DHPG via DREAM and ERAD in acute ischemic stroke rats. One, 10 or 100 μM (S)-3,5-DHPG was administered intrathecally to 6 adult male Sprague Dawley rats 2 hours prior to the middle cerebral artery occlusion. After 24 hours, the modified neurological severity score (mNSS) and grid walking test were assessed. The rats were sacrificed and the infarct brain volumes were estimated by 2,3,5-triphenyltetrazolium chloride staining. The serum level of neuron-specific enolase (NSE) and brain tissue level of Bip/GRP78 ER stress marker were assessed by ELISA assays. The ischemic penumbra tissue surrounding the ischemic core infarct was dissected and the cytoplasmic and nuclear proteins as well as the total RNA were extracted. The protein levels of nuclear and cytoplasmic DREAM, as well as EDEM1, SEC61α and VCP were analysed by Western blot. The expression of dream and edem1 genes were analysed by qRT-PCR. Finally, the level of protein degradation activity in the ischemic penumbra tissue was determined by the 20S proteasomal assay. One or 10 μM of (S)-3,5-DHPG preconditioning in stroke rats has significantly improved the neurological functions and reduced the brain infarction as well as the NSE level. The DREAM protein has significantly increased in the nuclear compartment after 2 hours of 1 μM (S)-3,5-DHPG administration and in the cytoplasmic compartment after 24 hours of 100 μM (S)-3,5DHPG administration. Similarly, 1 μM (S)-3,5-DHPG preconditioning has significantly reduced the levels of Bip/GRP78 ER stress marker, DREAM and ERAD proteins as well as proteasomal degradation activity after 24 hours of an ischemic stroke. The expression of dream and edem1 gene were decreased in 1 μM (S)-3,5DHPG preconditioning compared to non-preconditioning ischemic stroke rats. In conclusion, the 1 and 10 μM of (S)-3,5-DHPG preconditioning enhanced the endogenous protective mechanism via promoting the nuclear DREAM protein to regulate the expression of EDEM1 and ERAD activities in order to alleviate subsequent ischemic injury in the brain whereas 100 μM of (S)-3,5-DHPG preconditioning exacerbated the ischemic injury.
format	Thesis
qualification_name	Doctor of Philosophy (PhD.)
qualification_level	Doctorate
author	Nik Ramli, Nik Nasihah
author_facet	Nik Ramli, Nik Nasihah
author_sort	Nik Ramli, Nik Nasihah
title	The neuroprotective mechanism of DREAM via ERAD pathway in dihydroxyphenylglycine preconditioned acute ischemic stroke rats / Nik Nasihah Nik Ramli
title_short	The neuroprotective mechanism of DREAM via ERAD pathway in dihydroxyphenylglycine preconditioned acute ischemic stroke rats / Nik Nasihah Nik Ramli
title_full	The neuroprotective mechanism of DREAM via ERAD pathway in dihydroxyphenylglycine preconditioned acute ischemic stroke rats / Nik Nasihah Nik Ramli
title_fullStr	The neuroprotective mechanism of DREAM via ERAD pathway in dihydroxyphenylglycine preconditioned acute ischemic stroke rats / Nik Nasihah Nik Ramli
title_full_unstemmed	The neuroprotective mechanism of DREAM via ERAD pathway in dihydroxyphenylglycine preconditioned acute ischemic stroke rats / Nik Nasihah Nik Ramli
title_sort	neuroprotective mechanism of dream via erad pathway in dihydroxyphenylglycine preconditioned acute ischemic stroke rats / nik nasihah nik ramli
granting_institution	Universiti Teknologi MARA (Kampus Sg. Buloh)
granting_department	Faculty of Medicine
publishDate	2016
url	https://ir.uitm.edu.my/id/eprint/62457/1/62457.pdf
_version_	1783735256662147072

The neuroprotective mechanism of DREAM via ERAD pathway in dihydroxyphenylglycine preconditioned acute ischemic stroke rats / Nik Nasihah Nik Ramli

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