Papers by Gilles Guillemin
Frontiers in Cellular Neuroscience, 2019
Advancement of science has gifted the human a longer life; however, as neuron cells do not regene... more Advancement of science has gifted the human a longer life; however, as neuron cells do not regenerate, the number of people with neurodegenerative disorders rises with population aging. Neurodegenerative diseases occur as a result of neuronal cells loss caused by environmental factors, genetic mutations, proteopathies, and other cellular dysfunctions. The negative direct or indirect contributions of various microorganisms in onset or severity of some neurodegenerative disorders and interaction between human immune system and pathogenic microorganisms has been portrayed in this review. This association may explain the early onset of neurodegenerative disorders in some individuals, which can be traced through detailed study of health background of these individuals for infection with any microbial disease with neuropathogenic microorganisms (bacteria, fungi, viruses). A better understanding and recognition of the relation between microorganisms and neurodegenerative disorders may help researchers in development of novel remedies to avoid, postpone, or make neurodegenerative disorders less severe.
Obesity (Silver Spring, Md.), 2016
The Faseb Journal, Apr 1, 2014
ABSTRACT Alzheimer disease (AD) is a neurodegenerative disease which is characterized by the pres... more ABSTRACT Alzheimer disease (AD) is a neurodegenerative disease which is characterized by the presence of extracellular senile plaques mainly composed of amyloid-β peptide (Aβ), intracellular neurofibrillary tangles, and selective synaptic and neuronal loss. AD brains revealed elevated levels of oxidative stress markers which have been implicated in Aβ-induced toxicity. Multiple components present in pomegranate and various pomegranate preparations are known to exert pleiotropic protective effects as demonstrated in various in vitro and in vivo model systems. The present study was designed to investigate the dietary supplementation of 4% pomegranate fruit grown in Oman on oxidative stress in the hippocampus, and hippocampal neuron injury in Tg2576 mice. The Tg 2576 mice were treated with 4% pomegranate by dietary supplementation for 15 months. After 15 months, the mice were sacrificed for measuring non-enzymatic [4-hydroxynonenal, TBARS, hydrogen peroxide, reduced glutathione (GSH), vitamin A, E, C and enzymatic antioxidants activity in the hippocampus, and expression of choline acetyltransferase (ChAT) positive neuron. The non-enzymatic and enzymatic antioxidants were significantly reduced along with elevated oxidative stress markers. Loss of ChAT positive neuron and severe damage to hippocampal neurons in Tg 2576 were also found. These abnormalities were significantly improved by 4% pomegranate treatment. In contrast, administration of 4% pomegranate diet to mice strongly suggested a putative delay in the formation of plaques, as indicated by a decreasing tendency of soluble and fibrillar Aβ levels in hippocampus which correlated with a decrease in Aβ (1-40, 1-42) plasma content. The study suggests that pomegranate could offer protection against neuronal injury and oxidative stress, and may be used as a potential agent in treatment of neurodegenerative diseases such as AD. This project was supported by a research grant from The Research Council, Oman (RC/AGR/FOOD/11/01).
PloS one, 2016
An increase of plasma kynurenine concentrations, potentially bioactive metabolites of tryptophan,... more An increase of plasma kynurenine concentrations, potentially bioactive metabolites of tryptophan, was found in subjects with obesity, resulting from low-grade inflammation of the white adipose tissue. Bariatric surgery decreases low-grade inflammation associated with obesity and improves glucose control. Our goal was to determine the concentrations of all kynurenine metabolites after bariatric surgery and whether they were correlated with glucose control improvement. Kynurenine metabolite concentrations, analysed by liquid or gas chromatography coupled with tandem mass spectrometry, circulating inflammatory markers, metabolic traits, and BMI were measured before and one year after bariatric surgery in 44 normoglycemic and 47 diabetic women with obesity. Associations between changes in kynurenine metabolites concentrations and in glucose control and metabolic traits were analysed between baseline and twelve months after surgery. Tryptophan and kynurenine metabolite concentrations wer...
The Faseb Journal, Apr 1, 2014
The Faseb Journal, Apr 1, 2014
ABSTRACT Although there are no proven ways to delay onset or slow progression of Alzheimer&#3... more ABSTRACT Although there are no proven ways to delay onset or slow progression of Alzheimer's disease (AD), studies suggest that diet can affect risk. Dates palm fruit are good sources of minerals (Se, Cu, K and Mg), vitamins (C, A, B6, B9, B2, B3), dietary fiber and total phenolics and natural antioxidants (anthocyanins & ferulic acid). Polyphenols have been shown to be neuroprotective in different model systems. We asked whether dietary supplementation with 2% dates or 4% dates would influence behavior and AD like pathology in a transgenic mouse model. The four month old mice with double Swedish APP mutation (APPsw/Tg2576) were purchased from Taconic Farm, NY, USA. The experimental groups of APP-transgenic mice from the age of 4 months were fed custom-mix diets (pellets) containing 2% dates or 4% dates. The control groups, i.e. tg mice and wild-type mice were fed diet without dates. Animals from all groups were undergone behavioral assessments at the age of 4-5 months and 14-15 months by Morris water maze test (for spatial memory and learning ability), T maze test (for position discrimination learning ability), rota rod test (for psychomotor coordination), elevated plus maze test (for anxiety-related behavior) and open field test (anxiety) to analyze the effect of diet rich in dates on learning skills, memory, anxiety, locomotors activity, and motor coordination. Both the diets rich in 2% dates & 4% dates fed tg mice showed a significant improvement in memory, learning ability, anxiety and motor development compared to the AD tg mice on diet without 2% dates & 4% dates. The more effect was observed in 4% dates diet fed animals than 2% fed. Our results suggest that dietary supplementation of date palm fruits may have beneficial effect in reducing the risk, delaying the onset or slowing the progression of Alzheimer's disease.This project was supported by a research grant from The Research Council, Oman (RC/AGR/FOOD/11/01).
International Journal of Low Radiation, Mar 20, 2015
ABSTRACT Ionising radiation (γ or X-rays) is the mandatory tool to treat cancer despite its detri... more ABSTRACT Ionising radiation (γ or X-rays) is the mandatory tool to treat cancer despite its detrimental effects in particular on skin cells which lead to severe dermatological diseases and carcinogenesis. Natural antioxidants caffeic acid (CA), rosmarinic acid (RA), trans cinnamic acid (TCA), p-coumaric acid (PCA), and hydroxyphenyllactic acid (HPA) acid are known to be potent anticancer and antioxidant agents. Current study is designed to provide experimental evidence as these compounds offer radiation protection for skin cells. Non-toxic concentrations of CA, RA, TCA, PCA, and HPA were tested for radiation protection, γ-radiation induced intracellular reactive oxygen species (ROS) by flow cytometry and DNA double strand break in human keratinocytes (HaCaT cells) by immunocytochemistry. CA, RA and TCA pre-treatment can protect the HaCaT cells by 40%, 20%, 15% respectively through scavenging γ-radiation induced ROS and decreasing number of post irradiation 53bp1 foci. Inclusion of these compounds in chemo-radiotherapy could facilitate to achieve multiple target protection (i.e. anti-cancer and skin radio protectant).
International Journal of Tryptophan Research Ijtr, 2010
Comptes Rendus Des Seances De La Societe De Biologie Et De Ses Filiales, 1996
Data Revues 03698114 00550010 07001162, Dec 18, 2007
Advances in Experimental Medicine and Biology, Feb 1, 2003
There is good evidence that the kynurenine pathway (KP) and one of its products, quinolinic acid ... more There is good evidence that the kynurenine pathway (KP) and one of its products, quinolinic acid (QUIN) play a role in the pathogenesis of neurological diseases. Monocytic cells are known to be the major producers of QUIN. However, macrophages have the ability to produce approximately 20 to 30-fold more QUIN than microglia. The molecular origin of this difference has not been clarified yet. Using unstimulated and IFN-gamma-stimulated cultures of human fcetal microglia and adult macrophages, we assayed mRNA expression of 8 key enzymes of the KP using RT-PCR and QUIN production using GC-MS. We found that after stimulation with IFN-gamma microglia produced de novo 20-fold less QUIN than macrophages. This quantitative difference in the ability to produce QUIN appears to be associated with a lower expression of 3 important enzymes of the KP in microglia: indoleamine 2,3-dioxygenase (IDO), kynureninase (KYNase) and kynurenine hydroxylase (KYN(OH)ase). These results suggest that activated infiltrating macrophages are the most potent QUIN producers during brain inflammatory diseases with playing a lesser role.
Frontiers in Cellular Neuroscience, 2015
Although there are seven mammalian sirtuins (SIRT1-7), little is known about their expression in ... more Although there are seven mammalian sirtuins (SIRT1-7), little is known about their expression in the aging brain. To characterize the change(s) in mRNA and protein expression of SIRT1-7 and their associated proteins in the brain of "physiologically" aged Wistar rats. We tested mRNA and protein expression levels of rat SIRT1-7, and the levels of associated proteins in the brain using RT-PCR and western blotting. Our data shows that SIRT1 expression increases with age, concurrently with increased acetylated p53 levels in all brain regions investigated. SIRT2 and FOXO3a protein levels increased only in the occipital lobe. SIRT3-5 expression declined significantly in the hippocampus and frontal lobe, associated with increases in superoxide and fatty acid oxidation levels, and acetylated CPS-1 protein expression, and a reduction in MnSOD level. While SIRT6 expression declines significantly with age acetylated H3K9 protein expression is increased throughout the brain. SIRT7 and Pol I protein expression increased in the frontal lobe. This study identifies previously unknown roles for sirtuins in regulating cellular homeostasis and healthy aging.
Toxicon : official journal of the International Society on Toxinology, Jan 19, 2015
This study utilised a proteomics approach to identify any differential protein expression in a gl... more This study utilised a proteomics approach to identify any differential protein expression in a glial cell line, rat olfactory ensheathing cells (OECs), treated with the cyanotoxin β-methylamino-l-alanine (BMAA). Five proteins of interest were identified, namely Rho GDP-dissociation inhibitor 1 (RhoGDP1), Nck-associated protein 1 (NCKAP1), voltage-dependent anion-selective channel protein 1 (VDAC1), 3-hydroxyacyl-CoA dehydrogenase type-2 (3hCoAdh2), and ubiquilin-4 (UBQLN4). Four of these candidates, nuclear receptor subfamily 4 group A member 1 (Nur77), cyclophilin A (CyPA), RhoGDP1 and VDAC1, have been reported to be involved in cell growth. A microarray identified UBQLN4, palladin and CyPA, which have been implicated to have roles in excitotoxicity. Moreover, the NCKAP1, UBQLN4, CyPA and 3hCoAdh2 genes have been associated with abnormal protein aggregation. Differential expression of genes involved in mitochondrial activity, Nur77, 3hCoAdh2, VDAC1 and UBQLN4, were also identified....
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Papers by Gilles Guillemin