Adverse events of recreational cannabis use during pregnancy reported to the French Addictovigilance Network between 2011 and 2020.

Cannabis is the main illicit psychoactive substance used by pregnant women in France. The aim of the present national survey was to describe adverse events (AEs) of recreational cannabis use during pregnancy reported to the French Addictovigilance Network (FAN). Spontaneous reports (SRs) of AEs related to recreational cannabis use during pregnancy were collected by the FAN between 01/01/2011 and 31/01/2021 (excluding cannabidiol and synthetic cannabinoids). Over the study period, 160 SRs involved cannabis use alone or in association with tobacco (59% of all SRs) which increased. Among the 175 maternal AEs, the most commons were psychiatric AEs experienced by 96 (64.9%) women, in particular cannabis use disorders (n = 89, 60.1%), dependence (n = 54, 36.5%) and abuse (n = 21, 14.2%). Among the 57 fetal AEs, the most common were heart rhythm disorders that affected 25 (16.9%) fetuses and intrauterine growth restriction (IUGR) (n = 20, 13.5%). Among the 140 neonatal AEs, the most common were IUGR experienced by 39 (26.3%) newborns and prematurity (n = 32, 21.6%). Twelve cases of congenital malformations were observed and 4 intrauterine/neonatal deaths. Furthermore, some of these AEs (n = 13) were unexpected. Cannabis use during pregnancy has problematic consequences for both mothers and infants who need close monitoring.

Adverse events of recreational cannabis use reported to the French addictovigilance network (2012-2017).

AIMS: To describe the adverse events (AEs) of recreational cannabis use in France between 2012 and 2017. METHODS: AEs related to recreational cannabis use, alone or in combination with alcohol and/or tobacco reported to the French Addictovigilance Network were analysed (excluding cannabidiol and synthetic cannabinoids). RESULTS: Reporting of AEs tripled between 2012 (n = 179, 6.3%, 95% confidence interval [CI] = 5.4-7.2) and 2017 (n = 562, 10.1%, 95% CI = 9.3-10.9), reaching 2217 cases. They concerned mainly men (76.4%) and users aged between 18 and 34 years (18-25: 30.9%; 26-34: 26.3%, range: 12-84 years). Cannabis was mainly inhaled (71.6%) and exposure was most often chronic (64.2%). Many types of AEs were reported: psychiatric (51.2%), neurological (15.6%), cardiac (7.8%) and gastrointestinal (7.7%), including unexpected AEs (n = 34, 1.1%). The most common effect was dependence, ranging from 10.1% (95% CI = 7.9-12.3) to 20.3% (95% CI = 17.3-23.2) over the study period. Cannabinoid hyperemesis syndrome (n = 87, 2.8%) emerged from 2015. Deaths accounted for 0.2% of all AEs (4 men and 3 women aged on average 35 years). A chronic pattern of cannabis use was reported in 4 of them (intracranial hypertension in the context of lung cancer, suicide, cerebral haematoma, neonatal death with concomitant chronic alcohol use), while in the other cases the toxicological analysis identified cannabis use (ruptured aneurysm and unknown aetiology). CONCLUSION: This study showed a multitude of AEs related to recreational cannabis use, including unexpected AEs and deaths. It highlights the problem of dependence and the emergence of cannabinoid hyperemesis syndrome.

Natural stilbenes effects in animal models of Alzheimer's disease.

Alzheimer's disease is one of the most frequent neurodegenerative diseases. This pathology is characterized by protein aggregates, mainly constituted by amyloid peptide and tau, leading to neuronal death and cognitive impairments. Drugs currently proposed to treat this pathology do not prevent neurodegenerative processes and are mainly symptomatic therapies. However, stilbenes presenting multiple pharmacological effects could be good potential therapeutic candidates. The aim of this review is to gather the more significant papers among the broad literature on this topic, concerning the beneficial effects of stilbenes (resveratrol derivatives) in animal models of Alzheimer's disease. Indeed, numerous studies focus on cellular models, but an in vivo approach remains of primary importance since in animals (mice or rats, generally), bioavailability and metabolism are taken into account, which is not the case in in vitro studies. Furthermore, examination of memory ability is feasible in animal models, which strengthens the relevance of a compound with a view to future therapy in humans. This paper is addressed to any researcher who needs to study untested natural stilbenes or who wants to experiment the most effective natural stilbenes in largest animals or in humans. This review shows that resveratrol, the reference polyphenol, is largely studied and seems to have interesting properties on amyloid plaques, and cognitive impairment. However, some resveratrol derivatives such as gnetin C, trans-piceid, or astringin have never been tested on animals. Furthermore, pterostilbene is of particular interest, by its improvement of cognitive disorders and its neuroprotective role. It could be relevant to evaluate this molecule in clinical trials.

Relevance of electroencephalogram assessment in amyloid and tau pathology in rat.

In order to contribute to a better knowledge on the relationship between amyloid and tau pathology, and electroencephalography (EEG) disturbances, the aim of this study was to evaluate the effects of injection of beta amyloid Abeta(1-42) peptide, tau (a recombinant AAV (Adeno-Associated Virus) containing the human transgene tau with the P301 L mutation on rats and the combination of both, on the power of brain's rhythm (delta, theta, alpha, beta and gamma waves) during the different sleep/wake states of animals by EEG recording. Currently, no preclinical studies explore the effect of the tau pathology on EEG. The experimentations were performed 3 weeks and 3 months post injections. Beta amyloid deposits and hyperphosphorylated Tau are observed by immunohistofluorescence, only in the hippocampus. Furthermore, using a radial arm water maze, the main effect was observed on working memory which was significantly impaired in Abeta-Tau group only 3 months post injections. However, on EEG, as early as the 3rd week, an overall decrease of the EEG bands power was observed in the treated groups, particularly the theta waves during the rapid eye movement (REM) sleep. Beta amyloid was mainly involved in these perturbations. Obviously, EEG seems to be an interesting tool in the early diagnostic of amyloid and tau pathologies, with a good sensitivity and the possibility to perform a follow up during a large period.

Natural polyphenols effects on protein aggregates in Alzheimer's and Parkinson's prion-like diseases.

Alzheimer's and Parkinson's diseases are the most common neurodegenerative diseases. They are characterized by protein aggregates and so can be considered as prion-like disease. The major components of these deposits are amyloid peptide and tau for Alzheimer's disease, α-synuclein and synphilin-1 for Parkinson's disease. Drugs currently proposed to treat these pathologies do not prevent neurodegenerative processes and are mainly symptomatic therapies. Molecules inducing inhibition of aggregation or disaggregation of these proteins could have beneficial effects, especially if they have other beneficial effects for these diseases. Thus, several natural polyphenols, which have antioxidative, anti-inflammatory and neuroprotective properties, have been largely studied, for their effects on protein aggregates found in these diseases, notably in vitro. In this article, we propose to review the significant papers concerning the role of polyphenols on aggregation and disaggregation of amyloid peptide, tau, α-synuclein, synphilin-1, suggesting that these compounds could be useful in the treatments in Alzheimer's and Parkinson's diseases.

Copper brain protein protection against free radical-induced neuronal death: Survival ratio in SH-SY5Y neuroblastoma cell cultures.

In Creutzfeldt Jakob, Alzheimer and Parkinson diseases, copper metalloproteins such as prion, amyloid protein precursor and α-synuclein are able to protect against free radicals by reduction from cupric Cu+2 to cupreous Cu+. In these pathologies, a regional copper (Cu) brain decrease correlated with an iron, zinc or manganese (Mn) increase has previously been observed, leading to local neuronal death and abnormal deposition of these metalloproteins in ß-sheet structures. In this study we demonstrate the protective effect of Cu metalloproteins against deleterious free-radical effects. With neuroblastoma SH-SY5Y cell cultures, we show that bovine brain prion protein in Cu but not Mn form prevents free radical-induced neuronal death. The survival ratio of SH-SY5Y cells has been measured after UV irradiation (free radical production), when the incubating medium is supplemented with bovine brain homogenate in native, Cu or Mn forms. This ratio, about 28% without any addition or with bovine brain protein added in Mn form, increases by as much as 54.73% with addition to the culture medium of native bovine brain protein and by as much as 95.95% if the addition is carried out in cupric form. This protective effect of brain copper protein against free radical-induced neuronal death has been confirmed with Inductively Coupled Plasma Mass Spectrometry Mn and Cu measurement in bovine brain homogenates: respectively lower than detection limit and 9.01µg/g dry weight for native form; lower than detection limit and 825.85µg/g dry weight for Cu-supplemented form and 1.75 and 68.1µg/g dry weight in Mn-supplemented brain homogenate.

Optimisation of Direct Copper Determination in Human Breast Milk Without Digestion by Zeeman Graphite Furnace Atomic Absorption Spectrophotometry with Two Chemical Modifiers.

Milk is an important food in the human diet, and copper (Cu) in human milk is indispensable to children's normal growth and development. It is consequently important that Cu deficiency, occurring in malnourished women or in malabsorption following bariatric surgery, be prevented. The objective of this work is to provide hospital-based paediatricians with a tool enabling rapid measurement of Cu in human breast milk through a technique that biology laboratories can easily apply. Using electrothermal atomic absorption spectrophotometry with Zeeman correction, we have optimized this method with two chemical modifiers and without digestion for analytical procedure. Detection limits and quantification limits for Cu in human milk were found to be 0.077 and 0.26 µmol/L, respectively. Within-run (n = 30) and between-run (n = 15) variations in a pool of human milk samples were 1.50 and 3.62%, respectively. Average recoveries ranged from 98.67 to 100.61%. The reliability of this method was also confirmed by analysing certified reference material (10%). In breast milk samples collected from 100 lactating mothers, Cu mean (±1 SD) was 7.09 ± 1.60 µmol/L. In conclusion, with minimal preparation and quick determination, the method proposed is suitable for measurement of Cu in human breast milk.

Interlaboratory comparison study on lead in blood, in external quality assessment schemes since 1996: a progress report.

In 1992, at the request of the French labor ministry, an External Quality Control for lead in whole blood (F-EQCPbB) came into being. After 15 years (1996-2011), the ministry wished to exploit the database collected with a sufficient number of laboratories. Indeed, the number of participating laboratories had decreased from 73 to 41. However, the key finding pertained to the highly improved performance of the laboratories, which was associated with a spread of the results over the entire range of tested PbB (9 and 700 µg/l). So, it was that in laboratories having participated for >10 years, the good scores rose between 1996 and 2011 from 49% to 93%. To sum up, analysis has shown progressive and highly pronounced diminution of CVs (%) for all the ranges having undergone testing. We have observed increasing use of inductively coupled plasma with mass spectrometry (from 9% in 2005 to 29% in 2011) and decreasing use of electrothermal atomic absorption spectrometry. That said, and provided that they are based on the same degree of expertise in metrology, on all tested concentrations the two analytical techniques yield results that are not statistically different. Thanks to the F-EQCPbB, laboratories have enhanced their proficiency and registered demonstrably improved performance.

[The external quality assessment schemes for lead in blood organized by the French national agency for medicine and health product safety: a synthesis of 15 years of activity]. / L'évaluation externe de la qualité des analyses de plombémie organisée par l'Agence nationale de sécurité du médicament et des produits de santé : bilan de 15 années de contrôle.

In 1992, at the request of the French labor ministry following questions on the ability of medical biology laboratories to satisfactorily measure blood lead level (PbB), a national PbB quality control came into being. Only in 1996 did this external quality control include a number of laboratories sufficient to allow for a significant retrospective evaluation. After fifteen years (1996-2011), The French National Agency for Medicines and Health Products Safety wished to exploit the database collected. The number of participating laboratories went down from 73 to 41. On the other hand, the key finding pertained to the highly improved performance of the laboratories, which was associated with a spread decrease of the results over the entire range of tested PbBs (9 to 700 µg/L). Since 2006, we have observed increasing use of the inductively coupled plasma with mass spectrometry and decreasing use of electrothermal atomic absorption spectrometry. Provided that they rely on identical metrology expertise, the two analytical techniques lead to results on all the tested concentrations that are not statistically different.

If exposure to aluminium in antiperspirants presents health risks, its content should be reduced.

Since aluminium (Al) pervades our environment, the scientific community has for many years raised concerns regarding its safety in humans. Al is present in numerous cosmetics such as antiperspirants, lipsticks and sunscreens. Al chlorohydrate is the active antiperspirant agent in underarm cosmetics and may constitute for Al a key exposure route to the human body and a potential source of damage. An in vitro study has demonstrated that Al from antiperspirant can be absorbed through viable human stripped skin. The potential toxicity of Al has been clearly shown and recent works convincingly argue that Al could be involved in cancerogenic processes. Nowadays, for example, Al is suspected of being involved in breast cancer. Recent work in cells in culture has lent credence to the hypothesis that this metal could accumulate in the mammary gland and selectively interfere with the biological properties of breast epithelial cells, thereby promoting a cascade of alterations reminiscent of the early phases of malignant transformation. In addition, several studies suggest that the presence of Al in human breast could influence metastatic process. As a consequence, given that the toxicity of Al has been widely recognized and that it is not a physiological component in human tissues, reducing the concentration of this metal in antiperspirants is a matter of urgency.

Aluminium overload after 5 years in skin biopsy following post-vaccination with subcutaneous pseudolymphoma.

Aluminium hydroxide is used as an effective adjuvant in a wide range of vaccines for enhancing immune response to the antigen. The pathogenic role of aluminium hydroxide is now recognized by the presence of chronic fatigue syndrome, macrophagic myofasciitis and subcutaneous pseudolymphoma, linked to intramuscular injection of aluminium hydroxide-containing vaccines. The aim of this study is to verify if the subcutaneous pseudolymphoma observed in this patient in the site of vaccine injection is linked to an aluminium overload. Many years after vaccination, a subcutaneous nodule was discovered in a 45-year-old woman with subcutaneous pseudolymphoma. In skin biopsy at the injection site for vaccines, aluminium (Al) deposits are assessed by Morin stain and quantification of Al is performed by Zeeman Electrothermal Atomic Absorption Spectrophotometry. Morin stain shows Al deposits in the macrophages, and Al assays (in µg/g, dry weight) were 768.10±18 for the patient compared with the two control patients, 5.61±0.59 and 9.13±0.057. Given the pathology of this patient and the high Al concentration in skin biopsy, the authors wish to draw attention when using the Al salts known to be particularly effective as adjuvants in single or repeated vaccinations. The possible release of Al may induce other pathologies ascribed to the well-known toxicity of this metal.

In vitro study of percutaneous absorption of aluminum from antiperspirants through human skin in the Franz™ diffusion cell.

Aluminum salts such as aluminum chlorohydrate (ACH) are known for use as an active antiperspirant agent that blocks the secretion of sweat. A local case report of hyperaluminemia in a woman using an aluminum-containing antiperspirant for 4 years raises the problem of transdermal absorption of aluminum (Al). Only a very limited number of studies have shown that the skin is an effective barrier to transdermal uptake of Al. In accordance with our analytical procedure, the aim of this study with an in vitro Franz™ diffusion cell was to measure aluminum uptake from three cosmetic formulations of antiperspirant: the base for an "aerosol" (38.5% of ACH), a "roll-on" emulsion (14.5% ACH), and a "stick" (21.2%), by samples of intact and stripped human skin (5 donors). The Al assays were performed by Zeeman Electrothermal Atomic Absorption Spectrophotometry (ZEAAS). Following contacts lasting 6, 12 and 24h, the Al assays showed only insignificant transdermal absorption of Al (≤0.07% of the quantity of Al deposited) and particularly low cutaneous quantities that varied according to the formulations (1.8 µg/cm² for "aerosol base" and "stick" - 0.5 µg/cm² for the "roll-on"). On stripped skin, for which only the "stick" formulation was tested, the measured uptake was significantly higher (11.50 µg/cm² versus 1.81 µg/cm² for normal skin). These results offer reassurance as regards to the use of antiperspirants for topical application of ACH-containing cosmetic formulations on healthy skin over a limited time span (24h). On the other hand, high transdermal Al uptake on stripped skin should compel antiperspirant manufacturers to proceed with the utmost caution.

Pharmacological inhibition of PKR in APPswePS1dE9 mice transiently prevents inflammation at 12 months of age but increases Aß42 levels in the late stages of the Alzheimer's disease.

The double-stranded RNA-dependent protein kinase (PKR) is switched on by a wide range of stimuli, including the amyloid peptide. Then, PKR transmits signals to the translational machinery, apoptosis and inflammatory signaling pathways by interacting with some adapters. In virus-infected cells, PKR engages the nucleus factor κB (NF-κB) pathway. In many models of Alzheimer's disease (AD) and patients with AD, PKR was activated. Furthermore, there is strong evidence implicating the inflammatory process in the AD brain. However, the PKR involvement in inflammatory responses in AD is not elucidated. Based on our previous in vitro results, the aim of this study was to evaluate the effects of a pharmacological inhibition of PKR in inflammation in APPswePS1dE9 transgenic mice. Our results showed that PKR inhibition prevented the NF-κB activation and production of tumor necrosis factor alpha (TNFα) and interleukin (IL)-1ß at 12 months of age without decrease of Aß42 levels and memory deficits. Surprisingly, PKR inhibition failed to prevent IL-1ß- mediated inflammation and induced a great increase in ß-amyloid peptide (Aß42) levels at 18 months of age. In this model, our findings highlight the lack of relationship between inflammation and Aß42 levels. Moreover, the age-dependent inflammatory response must be carefully taken into account in the establishment of an anti-inflammatory therapy in AD.

An analytical procedure for the determination of aluminum used in antiperspirants on human skin in Franz™ diffusion cell.

A local case report of hyperaluminemia (aluminum concentration: 3.88 µmol/L) in a woman using an aluminum-containing antiperspirant for 4 years raises the question of possible transdermal uptake of aluminum salt as a future public health problem. Prior to studying the transdermal uptake of three commercialized cosmetic formulas, an analytical assay of aluminum (Al) in chlorohydrate form (ACH) by Zeeman Electrothermal Atomic Absorption Spectrophotometer (ZEAAS) in a clean room was optimized and validated. This analysis was performed with different media on human skin using a Franz(™) diffusion cell. The detection and quantification limits were set at ≤ 3 µg/L. Precision analysis as within-run (n = 12) and between-run (n = 15-68 days) yield CV ≤ 6%. The high analytic sensitivity (2-3 µg/L) and low variability should allow an in vitro study of the transdermal uptake of ACH.

Lithium chloride and staurosporine potentiate the accumulation of phosphorylated glycogen synthase kinase 3ß/Tyr216, resulting in glycogen synthase kinase 3ß activation in SH-SY5Y human neuroblastoma cell lines.

Glycogen synthase kinase 3ß (GSK3ß) activity is regulated by phosphorylation processes and regulates in turn through phosphorylation several proteins, including eukaryotic initiation factor 2B (eIF2B). Serine 9 phosphorylation of GSK3ß (pGSK3ßSer9), usually promoted by activation of the PI3K/Akt survival pathway, triggers GSK3ß inhibition. By contrast, tyrosine 216 phosphorylation of GSK3ß (pGSK3ßTyr216) increases under apoptotic conditions, leading to GSK3ß activation. Lithium chloride (LiCl) is usually described to increase pGSK3ßSer9 through the PI3K/Akt pathway, resulting in GSK3ß inhibition. The purpose of this study is to demonstrate that in some cases LiCl is also able to increase pGSK3ßTyr216, resulting in GSK3ß activation. For this, we used SH-SY5Y cells and primary neuronal cultures and investigated the effects of LiCl on the two phosphorylated forms of GSK3ß under staurosporine (STS)-intoxicated conditions. The ratios between the phosphorylated and total forms of GSK3ß and eIF2B were determined by Western blotting. Our results revealed that, besides its ability to increase pGSK3ßSer9, LiCl is also able to increase pGSK3ßTyr216 greatly in STS-intoxicated SH-SY5Y cells but not in STS-intoxicated primary neuronal cultures. This accumulation of both Ser9 and Tyr216 phosphorylation results in GSK3ß activation in STS-intoxicated SH-SY5Y cells in spite of the presence of LiCl. These findings indicate that LiCl treatment is not necessarily correlated with GSK3ß inhibition even though it generates Ser9 phosphorylation. Consequently, the ratio pGSK3ßSer9/pGSK3ßTyr216, which takes into account the balance between the two inactive (Ser9) and active (Tyr216) forms of GSK3ß, could be more useful for predicting GSK3ß inhibition.

Interaction of double-stranded RNA-dependent protein kinase (PKR) with the death receptor signaling pathway in amyloid beta (Abeta)-treated cells and in APPSLPS1 knock-in mice.

For 10 years, research has focused on signaling pathways controlling translation to explain neuronal death in Alzheimer Disease (AD). Previous studies demonstrated in different cellular and animal models and AD patients that translation is down-regulated by the activation of double-stranded RNA-dependent protein kinase (PKR). Among downstream factors of PKR, the Fas-associated protein with a death domain (FADD) and subsequent activated caspase-8 are responsible for PKR-induced apoptosis in recombinant virus-infected cells. However, no studies have reported the role of PKR in death receptor signaling in AD. The aim of this project is to determine physical and functional interactions of PKR with FADD in amyloid-beta peptide (Abeta) neurotoxicity and in APP(SL)PS1 KI transgenic mice. In SH-SY5Y cells, results showed that Abeta42 induced a large increase in phosphorylated PKR and FADD levels and a physical interaction between PKR and FADD in the nucleus, also observed in the cortex of APP(SL)PS1 KI mice. However, PKR gene silencing or treatment with a specific PKR inhibitor significantly prevented the increase in pT(451)-PKR and pS(194)-FADD levels in SH-SY5Y nuclei and completely inhibited activities of caspase-3 and -8. The contribution of PKR in neurodegeneration through the death receptor signaling pathway may support the development of therapeutics targeting PKR to limit neuronal death in AD.

Neuroprotective effect of PACAP on translational control alteration and cognitive decline in MPTP parkinsonian mice.

Parkinson's disease (PD) is characterized by a triade of motor symptoms due to the degeneration of nigrostriatal pathway. In addition to these motor impairments, cognitive disturbances have been reported to occur in PD patients in the early stage of the disease. The 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a neurotoxin widely used to produce experimental models of PD. In a previous work, we showed that MPTP altered the expression of proteins involved in mTOR antiapoptotic and PKR apoptotic pathways of translational control (TC) in neuroblastoma cells. In the present study, the results indicated that a subchronic MPTP intoxication in mice decreased the dopaminergic neuron number, produced an activation of PKR way and an inhibition of mTOR way of TC especially in striatum and frontal cortex associated with a great activation of PKR in hippocampus. Moreover, in parallel to biochemical analysis, the mnesic disturbances induced by MPTP were characterized in C57Bl/6 mice, by testing their performance in three versions of the Morris Water Maze task. Behavioral results showed that the MPTP lesion altered mice learning of a spatial working memory, of a cued version and of a spatial reference memory task in the water maze. Furthermore, we previously demonstrated that the neuropeptide pituitary adenylate cyclase activating polypeptide (PACAP) could counteract the MPTP toxicity on TC factors in neuroblastoma cells. Thus, the second objective of our study was to assess the PACAP effect on MPTP-induced TC impairment and cognitive deficit in mice. The pretreatment with PACAP27 by intravenous injections partially protected TH-positive neuron loss induced by MPTP, prevented the MPTP-induced protein synthesis control dysregulation and mnesic impairment of mice. Therefore, our results could indicate that PACAP may be a promising therapeutic agent in Parkinson's disease.

Inhibition of double-stranded RNA-dependent protein kinase strongly decreases cytokine production and release in peripheral blood mononuclear cells from patients with Alzheimer's disease.

Alzheimer's disease (AD), a neurodegenerative disorder, is the most common form of dementia in the elderly individuals. Among the pathogenic mechanisms in AD, chronic systemic inflammation is described and characterized by massive production of proinflammatory cytokines by peripheral blood mononuclear cells (PBMCs), which may contribute to an altered immune response and exacerbation of neurodegeneration. Studies have also reported increased double-stranded RNA-dependent protein kinase (PKR) activation in the PBMCs of patients with AD. Interestingly, PKR could be involved in NF-κB activation, leading to production of a wide range of cytokines. We proposed to decrease proinflammatory cytokines production and release by treating the PBMCs in 25 patients with AD with a specific inhibitor of PKR. Our results showed that PKR inhibition greatly decreased tumor necrosis factor , interleukin (IL)-1α, IL-1ß, and IL-6 production and release but did not affect the chemokine RANTES. Moreover, inhibition of the proinflammatory factors was correlated with prevention of caspase-3 activation. These results indicated that specific inhibition of PKR at the peripheral level might decrease the inflammatory response in AD.

Evidence of molecular links between PKR and mTOR signalling pathways in Abeta neurotoxicity: role of p53, Redd1 and TSC2.

The control of translation is disturbed in Alzheimer's disease (AD). This study analysed the crosslink between the up regulation of double-stranded RNA-dependent-protein kinase (PKR) and the down regulation of mammalian target of rapamycin (mTOR) signalling pathways via p53, the protein Regulated in the Development and DNA damage response 1 (Redd1) and the tuberous sclerosis complex (TSC2) factors in two beta-amyloid peptide (Abeta) neurotoxicity models. In SH-SY5Y cells, Abeta42 induced an increase of P(T451)-PKR and of the ratio p66/(p66+p53) in nuclei and a physical interaction between these proteins. Redd1 gene levels increased and P(T1462)-TSC2 decreased. These disturbances were earlier in rat primary neurons with nuclear co-localization of Redd1 and PKR. The PKR gene silencing in SH-SY5Y cells prevented these alterations. p53, Redd1 and TSC2 could represent the molecular links between PKR and mTOR in Abeta neurotoxicity. PKR could be a critical target in a therapeutic program of AD.

Activation of the protein p7OS6K via ERK phosphorylation by cholinergic muscarinic receptors stimulation in human neuroblastoma cells and in mice brain.

Stimulation of cholinergic muscarinic receptors has been shown to provide substantial protection from DNA damage, oxidative stress and mitochondrial impairment, insults that may be encountered by neurons in development, aging, or neurodegenerative diseases. A study recently indicated that the activation of muscarinic receptors in astrocytoma cells modified the expression of the kinase p70S6K involved in the translational control. The translational control is in part regulated by a cascade of phosphorylation affecting proteins of the anti-apoptotic way controlled by mTOR (mammalian target of rapamycin) and the pro-apoptotic way controlled by PKR. The aim of our study was to investigate the effect of cholinergic muscarinic stimulation by an agonist oxotremorine on the anti-apoptotic way of translational control, in human neuroblastoma cells and in mice brain. Our results showed that muscarinic receptor activation significantly increased the expression of phosphorylated p70S6K, eIF4E and ERK without modification of mTOR activity in neuroblastoma cells and in cerebral cortex and hippocampus of mice, suggesting a stimulation of protein synthesis. Our findings support the notion that synaptic activity, through activation of neurotransmitter receptors, can provide substantial support of cellular survival mechanisms and suggest that loss of such synaptic input increases vulnerability to insult-induced programmed cell death.