Cardiovascular hypertrophy: role of angiotensin II and bradykinin.

Angiotensin II can raise blood pressure rapidly by inducing direct vasoconstriction and by activating the sympathetic nervous system via central and peripheral mechanisms. In addition, this peptide may act as a growth factor to cause vascular and cardiac hypertrophy (CVH). The structural changes caused by hypertension can therefore be amplified by angiotensin II. Blockade of angiotensin II generation with angiotensin-converting enzyme (ACE) inhibitors appears to be particularly effective in preventing the development of cardiovascular hypertrophy. This beneficial effect might be related to some extent to local accumulation of bradykinin. ACE is one of the enzymes physiologically involved in bradykinin degradation. Treatment of hypertensive rats with a selective bradykinin antagonist can attenuate the blood pressure-lowering effect of ACE inhibition and render less effective the prevention of intimal thickening after endothelial removal from the rat carotid artery. Bradykinin is a vasodilator that acts by increasing the release of endothelium-derived factors such as nitric oxide and prostacyclin, which may have antiproliferative activity. However, blockade of the renin-angiotensin system with an angiotensin II subtype 1-receptor antagonist is also effective in preventing cardiac hypertrophy and neointimal proliferation after endothelial injury. Therefore, the exact contribution of bradykinin to the beneficial effects of ACE inhibition on cardiovascular hypertrophy remains to be further explored.

Are myotonic dystrophy and peripheral neuropathy associated? : morphological, morphometric and electrophysiological analysis in DM1 transgenic mice

Abstract: Myotonic dystrophy (DM1), also known as Steinert disease, is an inherited autosomal dominant disease. It is characterized by myotonia, muscular weakness and atrophy, but DM1 may have manifestations in other organs such as eyes, heart, gonads, gastrointestinal and respiratory tracts, as well as brain. In 1992, it was demonstrated that this complex disease results from the expansion of CTG repeats in the 3' untranslated region of the DM protein kinase (DMPK) gene on chromosome 19. The size of the inherited expansion is critically linked to the severity of the disease and the age of onset. Although several electrophysiological and histological studies have been carried out to verify the possible involvement of peripheral nerve abnormality with DM1, the results have not been univocal. Therefore, at present the possible association between peripheral neuropatliy and DM1 remains debated. Recently, transgenic mice have been generated, that carry the human genomic DM1 region with 300 CTG repeats, and display the human DMl phenotype. The generation of these DM1 transgenic mice provides a useful tool to investigate the type and incidence of structural abnormalities in the peripheral nervous system associated with DM1 disease. By using the DM1 transgenic mice, we investigated the presence/absence of the three major peripheral neuropathies: axonal degeneration, axonal demyelination and neuronopathy. The morphological and morphometric analysis of sciatic, sural and phrenic nerves demonstrated the absence of axonal degeneration or demyelination. The morphometric analysis also ruled out any loss in the numbers of sensory or motor neurons in lumbar dorsal root ganglia and lumbar spinal cord enlargement respectively. Moreover, the éxamination of serial hind limb muscle sections from DMl mice showed a normal intramuscular axonal arborization as well as the absence of changes in the number and structure of endplates. Finally, the electrophysiological tests performed in DM1 transgenic mice showed that the compound muscle axon potentials (CMAPs) elicited in the hind limb digits in response to a stimulation of the sciatic nerve with anear-nerve electrode were similar to thosé obtained in wild type mice. On the basis of all our results, we hypothesized that 300 CTG repeats are not sufficient to induce disorder in the peripheral nervous system of this DM1 transgenic mouse model. Résumé La dystrophie myotonique (DM1), connue aussi sous le nom de maladie de Steinert, est une maladie héréditaire autosornale dominante. Elle est caractérisée par une myotonie, une faiblesse et une atrophie musculaires, mais peut aussi se manifester dans d'autres organes tels que les yeux, les voies digestive et respiratoire, ou le cerveau. En 1992, il a été montré que cette maladie complexe résultait de l'expansion d'une répétition de CTG dans une partie non traduite en 3' du gène codant pour la protéine kinase DM (DMPK), sur le chromosome 19. La taille de l'expansion héritée est étroitement liée à la sévérité et l'âge d'apparition de DM1. Bien que plusieurs études électrophysiologiques et histologiques aient été menées, pour juger d'une implication possible d'anomalies au niveau du système nerveux périphérique dans la DM1, les résultats n'ont jusqu'ici pas été univoques. Aujourd'hui, la question d'une neuropathie associée avec la DM1 reste donc controversée. Des souris transgéniques ont été élaborées, qui portent la séquence DM1 du génome humain avec 300 répétitions CTG et expriment le phénotype des patients DM1: Ces souris transgéniques DMl procurent un outil précieux pour l'étude du type et de l'incidence d'éventuelles anomalies du système nerveux périphérique dans la DM1. En utilisant ces souris transgéniques DM1, nous avons étudié la présence ou l'absence des trois principaux types de neuropathies périphériques: la dégénération axonale, la démyélinisation axonale et la neuronopathie. Les études morphologiques et morphométrique des nerfs sciatiques, suraux et phréniques ont montré l'absence de dégénération axonale ou de démyélinisation. L'analyse du nombre de cellules neuronales n'a pas dévoilé de diminution des nombres de neurones sensitifs dans les ganglions des racines dorsales lombaires ou de neurones moteurs dans la moëlle épinière lombaire des souris transgéniques DMl. De plus, l'examen de coupes sériées de muscle des membres postérieurs de souris DM1 a montré une arborisation axonale intramusculaire normale, de même que l'absence d'irrégularité dans le nombre ou la structure des plaques motrices. Enfin, les tests électrophysiologiques effectués sur les souris DMl ont montré que les potentiels d'action de la composante musculaire (CMAPs) évoqués dans les doigts des membres postérieurs, en réponse à une stimulation du nerf sciatique à l'aide d'une électrode paranerveuse, étaient identiques à ceux observées chez les souris sauvages. Sur la base de l'ensemble de ces résultats, nous avons émis l'hypothèse que 300 répétitions CTG ne sont pas suffisantes pour induire d'altérations dans le système nerveux périphérique du modèle de souris transgéniques DM 1.

A developmental framework for endodermal differentiation and polarity.

The endodermis is a root cell layer common to higher plants and of fundamental importance for root function and nutrient uptake. The endodermis separates outer (peripheral) from inner (central) cell layers by virtue of its Casparian strips, precisely aligned bands of specialized wall material. Here we reveal that the membrane at the Casparian strip is a diffusional barrier between the central and peripheral regions of the plasma membrane and that it mediates attachment to the extracellular matrix. This membrane region thus functions like a tight junction in animal epithelia, although plants lack the molecular modules that establish tight junction in animals. We have also identified a pair of influx and efflux transporters that mark both central and peripheral domains of the plasma membrane. These transporters show opposite polar distributions already in meristems, but their localization becomes refined and restricted upon differentiation. This "central-peripheral" polarity coexists with the apical-basal polarity defined by PIN proteins within the same cells, but utilizes different polarity determinants. Central-peripheral polarity can be already observed in early embryogenesis, where it reveals a cellular polarity within the quiescent center precursor cell. A strict diffusion block between polar domains is common in animals, but had never been described in plants. Yet, its relevance to endodermal function is evident, as central and peripheral membranes of the endodermis face fundamentally different root compartments. Further analysis of endodermal transporter polarity and manipulation of its barrier function will greatly promote our understanding of plant nutrition and stress tolerance in roots.

Tolerogenic dendritic cells and their role in induction of immune tolerance

Les cellules dendritiques sont des cellules du système immunitaire qui permettent d'instruire les lymphocytes T, autres cellules de ce système, pour mettre en place une réponse immunitaire adaptée afin de combattre et vaincre une infection. Ces cellules dendritiques vont reconnaître des motifs spécifiquement exprimés par des pathogènes par l'intermédiaire de récepteurs exprimés à leur surface. En détectant ces molécules, elles vont s'activer et subir diverses modifications pour pouvoir activer les lymphocytes T. Elles vont alors interagir avec les lymphocytes Τ et transférer les informations nécessaires pour que ces cellules s'activent à leur tour et produisent différentes protéines de façon à éliminer le pathogène. En fonction du type de pathogène, les informations transférées entre les cellules dendritiques et les lymphocytes seront différentes de manière à produire la réponse immunitaire la mieux adaptée pour supprimer l'élément infectieux. Dans le corps, les cellules dendritiques circulent continuellement afin de détecter les éléments étrangers. Quand elles reconnaissent une protéine étrangère, elles la phagocytent, c'est-à-dire qu'elles la mangent afin de pouvoir la présenter aux lymphocytes T. Mais quand elles phagocytent un élément étranger, elles peuvent également prendre des éléments du soi, comme par exemple quand elles phagocytent une cellule infectée par un virus. Les cellules dendritiques doivent alors être capables de différentier les molécules du soi et du non-soi de façon à ne pas induire une réponse en présentant un antigène du soi aux lymphocytes T. D'autant plus que lors de leur développement, les lymphocytes Τ qui sont capables de reconnaître le soi sont éliminés mais ce système n'est pas parfait et donc certains lymphocytes Τ auto-reactifs peuvent se trouver dans le corps. Il existe ainsi d'autres mécanismes en périphérie du site de développement pour inhiber ces lymphocytes Τ auto-reactifs. Ce sont les mécanismes de tolérance. Quand les lymphocytes Τ induisent une réponse aux antigènes du soi, cela résulte à des maladies auto-immunes. Dans mon projet de recherche, nous avons travaillé avec des lignées de cellules dendritiques, c'est-à-dire des cellules dendritiques semblables à celles que l'on peut trouver in vivo mais qui sont immortalisées, elles peuvent donc être cultiver et manipuler in vitro. Nous avons génétiquement modifiées ces lignées cellulaires pour qu'elles expriment des molécules immunosuppressives afin d'étudier comment induire une tolérance immunitaire, c'est-à-dire si l'expression de ces molécules permet d'éviter de générer une réponse immunitaire. Pour cela, nous avons utilisé des modèles murins de tumeurs et de maladies auto-immunes. Nous avons démontré que ces lignées de cellules dendritiques peuvent être un grand outil de recherche pour étudier les bénéfices de différentes molécules immuno-modulatrices afin d'induire une tolérance immunitaire à différents antigènes. - Les cellules dendritiques sont responsables de l'induction des réponses immunitaires adaptatives. Suite à une infection microbienne, les cellules dendritiques s'activent, elles induisent l'expression de molécules de costimulation à leur surface, sécrètent des cytokines et induisent la différentiation des cellules Τ effectrices et mémoires. De plus, les cellules dendritiques ont un rôle important dans l'induction et la maintenance de la tolérance immunitaire au niveau du thymus et en périphérie, en induisant l'anergie, la délétion ou la conversion des cellules Τ naïves en cellules régulatrices. Dans notre groupe, une nouvelle lignée de cellules dendritiques appelée MuTu a été crée par la culture de cellules dendritiques tumorales isolées à partir d'une rate d'une souris transgénique, dans laquelle l'expression de l'oncogène SV40 et du GFP sont sous le contrôle du promoteur CD1 le, et sont ainsi spécifiquement exprimés dans les cellules dendritiques. Ces nouvelles lignées appartiennent au sous-type des cellules dendritiques conventionnelles exprimant CD8a. Elles ont conservé leur capacité d'augmenter l'expression des marqueurs de costimulation à leur surface ainsi que le production de cytokines en réponse à des ligands des récepteurs Toll, ainsi que leur capacité à présenter des antigènes associés aux molécules du complexe majeur d'histocompatibilité (CMH) de classe I ou II pour activer la prolifération et la différentiation des lymphocytes T. En utilisant un système de transduction de lentivirus de seconde génération, ces nouvelles lignées de cellules dendritiques ont été génétiquement modifiées pour sur-exprimer des molécules immunosuppressives (IL-10, TGFP latent, TGFp actif, Activin A, Arginase 1, IDO, B7DC et CTLA4). Ces lignées permettent d'étudier de manière reproductible le rôle de ces molécules potentiellement tolérogènes sur les réponses immunitaires in vitro et in vivo. Ces lignées potentiellement tolérogènes ont été testées, tout d'abord, in vitro, pour leur capacité à inhiber l'activation des cellules dendritiques, à bloquer la prolifération des cellules Τ ou à modifier leur polarisation. Nos résultats démontrent qu'en réponse à une stimulation, la sur-expression des molécules costimulatrices et la sécrétion de molécules pro- inflammatoires est réduite quand les cellules dendritiques sur-expriment l'IL-10. La sur¬expression de TGFp sous sa forme active induit le développement de cellules régulatrices CD4+ CD25+ Foxp3+ et bloque la réponse CD8 cytotoxique tandis que la sur-expression de CTLA4 à la surface des cellules dendritiques inhibe une réponse Thl et induit des lymphocytes Τ anergiques. Ces lignées ont également été utilisées pour étudier l'induction de tolérance in vivo. Tout d'abord, nous avons étudié l'induction de tolérance dans un modèle de développement de tumeurs. En effet, quand les lignées tumorales sont transférées dans les lignées de souris C57BL/6, elles sont reconnues comme du non-soi du à l'expression de l'oncogène SV40 et du GFP et sont éliminées. Ce mécanisme d'élimination a été étudié en utilisant une lignée de cellules dendritiques modifiée pour exprimer la luciférase et qui a permis de suivre le développement des tumeurs par de l'imagerie in vivo dans des animaux vivants. Ces lignées de cellules dendritiques MuTu sont éliminées dans la souris C57BL/6 par les lymphocytes CD8 et l'action cytotoxique de la perforine. Après plusieurs injections, les cellules dendritiques sur-exprimant CTLA4 ou l'actif TGFp peuvent casser cette réponse immunitaire inhérente aux antigènes de la lignée et induire le développement de la tumeur dans la souris C57BL/6. Le développement tumoral a pu être suivi en mesurant la bioluminescence émise par des cellules dendritiques modifiées pour exprimer à la fois l'actif TGFp et la luciférase. Ces tumeurs ont pu se développer grâce à la mise en place d'un microenvironnement suppressif pour échapper à l'immunité en recrutant des cellules myéloïde suppressives, des lymphocytes CD4 régulateurs et en induisant l'expression d'une molécule inhibitrice PD-1 à la surface des lymphocytes CD8 infiltrant la tumeur. Dans un deuxième temps, ces lignées tolérogènes ont également été testées dans un modèle murin de maladies auto-immunes, appelé l'encéphalomyélite auto-immune expérimental (EAE), qui est un modèle pour la sclérose en plaques. L'EAE a été induite dans la souris par le transfert de cellules de ganglions prélevées d'une souris donneuse préalablement immunisée avec une protéine du système nerveux central, la glycoprotéine myéline oligodendrocyte (MOG) émulsifiée dans de l'adjuvant complet de Freund. La vaccination des souris donneuses et receveuses avec les cellules sur-exprimant l'actif TGFP préalablement chargées avec la protéine MOG bloque l'induction de l'EAE. Nous sommes actuellement en train de définir les mécanismes qui permettent de protéger la souris du développement de la maladie auto-immune. Dans cette étude, nous avons ainsi démontré la possibilité d'induire la tolérance in vivo et in vitro à différents antigènes en utilisant nos nouvelles lignées de cellules dendritiques et en les modifiant pour exprimer des molécules immunosuppressives. En conséquence, ces nouvelles lignées de cellules dendritiques représentent un outil pour explorer les bénéfices de différentes molécules ayant des propriétés immuno-modulatrices pour manipuler le système immunitaire vers un phénotype tolérogène. - Dendritic cells (DC) are widely recognized as potent inducers of the adaptive immune responses. Importantly, after microbial infections, DC become activated, induce co- stimulation, secrete cytokines and induce effector and memory Τ cells. DC furthermore play an important role in inducing and maintaining central and peripheral tolerance by inducing anergy, deletion or commitment of antigen-specific naïve Τ cells into regulatory Τ cells. In our group, stable MuTu DC lines were generated by culture of splenic DC tumors from transgenic mice expressing the SV40 large Τ oncogene and the GFP under DC-specific CDllc promoter. These transformed DC belong to the CD8a+ conventional DC subtype and have fully conserved their capacity to upregulate co-stimulatory markers and produce cytokines after activation with Toll Like Receptors-ligands, and to present Major Histocompatibility class-I or MHCII-restricted antigens to activate Τ cell expansion and differentiation. Using a second- generation lentiviral transduction system, these newly developed MuTu DC lines were genetically modified to overexpress immunosuppressive molecules (IL-10, latent TGFp, active TGFp, Activin A, Arginase 1, IDO, B7DC and CTLA4). This allows to reproducibly investigate the role of these potentially tolerogenic molecules on in vitro and in vivo immune responses. These potentially tolerogenic DC were tested in vitro for their ability to inhibit DC activation, to prevent Τ cell proliferation and to modify Τ cell polarization. Our results show that the upregulation of costimulatory molecules and the secretion of pro-inflammatory cytokines were reduced upon stimulation of DC overexpressing IL-10. The overexpression of active TGFP induced the development of CD4+ CD25+ Foxp3+ regulatory Τ cells and inhibited the cytotoxic CD8 Τ cell response as shown by using the OT-II Τ cell system whereas the surface expression of CTLA-4 on DC prevented the Thl response and prompted an anergic antigen-specific Τ cell response. These MuTu DC lines were also used in vivo in order to study the induction of tolerance. First we addressed the induction of tolerance in a model of tumorogenesis. The adoptively transferred tumor cell lines were cleared in C57BL/6 mice due to the foreign expression of SV40 LargeT and GFP. The mechanism of clearance of MuTu DC line into C57BL/6 mice was investigated by using luciferase-expressing DC line. These DC line allowed to follow, by in vivo imaging, the tumor development in living animals and determined that MuTu DC lines were eliminated in a perforin-mediated CD8 Τ cell dependent and CD4 Τ cell independent response. After multiple injections, DC overexpressing CTLA4 or active TGFp could break the immune response to these inherent antigens and induced DC tumorogenesis in wild type mice. The tumor outgrowth in C57BL/6 mice was nicely observed by double-transduced DC lines to express both luciferase and active TGFp. actTGFp-DC tumor was shown to recruit myeloid-derived suppressor cells, induce CD4+ CD25+ Foxp3+ regulatory Τ cells and induce the expression of the inhibitory receptor PD-1 on tumor- infiltrating CD8+ Τ cells in order to escape tumor immunity. Tolerogenic DC lines were also tested for the induction of tolerance in a murine model of autoimmune disease, the experimental autoimmune encephalitis (EAE) model for human multiple sclerosis. EAE was induced in C57BL/6 mice by the adoptive transfer of lymph node cells isolated from donor mice previously immunized by a protein specific to the central nervous system, the myelin oligodendrocyte glycoprotein (MOG) emulsified in the complete freund adjuvant. The vaccination of donor and recipient mice with MOG-pulsed actTGFP-DC line prevented EAE induction. We are still investigating how the active TGFP protect mice from EAE development. We generated tolerogenic DC lines inducing tolerance in vitro and in vivo. Thereby these MuTu DC lines represent a great tool to explore the benefits of various immuno-modulatory molecules to manipulate the immune system toward a tolerogenic phenotype.

Anteromedian, central, and posterolateral infarcts of the thalamus : three variant types

Résumé Introduction et but: Les accidents vasculaires cérébraux (AVC) ischémiques thalamiques sont traditionnellement classés en quatre territoires : antérieur (polaire ou tubérothalamique), paramédian (ou thalamo-perforant), inférolatéral (ou thalamo-genouillé) et postérieur. Le but de cette thèse est de déterminer, à l'aide des techniques d'imagerie actuelles, si cette classification est appropriée ou si il existe d'autres territoires à la jonction entre les précédents territoires. Méthode: Nous avons étudié les 3712 patients hospitalisés pour un premier AVC dans le service de neurologie du CHUV à Lausanne et inclus dans le « Lausanne Stroke Registry » entre 1990 et 2002. Parmi les 71 patients avec un infarctus thalamique confirmé par IRM, nous avons sélectionné tous les patients présentant un AVC hors des quatre territoires classiques en étudiant leur tableau clinique, étiologique et radiologique. Résultats: 21 patients (30% des patients avec AVC thalamiques) avaient un AVC hors des quatre territoires classiques, permettant de délimiter trois nouveaux territoires. 1) territoire anteromédian (9 patients (13%)), atteignant la partie postérieure du territoire antérieur et la partie antérieure du territoire paramédian, avec en premier lieu des troubles cognitifs (principalement troubles dysexecutifs, amnésie antérograde ainsi qu'une aphasie dans les lésions gauches). L'étiologie principale était cardio-embolique. 2) territoire central (4 patients (6%)), atteignant la partie centrale du thalamus provoquant différents signes neurologiques et neuropsychologiques, reflétant l'atteinte de différentes structures. La cause la plus fréquente était microangiopathique. 3) territoire posterolateral (8 patients (8%)), atteignant la partie postérieure du territoire inférolatéral et la partie antérieure du territoire postérieur provoquant en premier lieu une hémihypesthesie mais aussi une hémiataxie ainsi que des troubles dysexécutifs et une aphasie dans les lésions gauches. Les étiologies les plus fréquentes étaient artério-artérielle et microangiopathique. Conclusions: Nous décrivons trois nouvelles variantes topographiques d'AVC thalamiques avec des tableaux cliniques et étiologiques distincts. Nous postulons que ces variantes sont le résultat de variations de la vascularisation thalamique ou reflètent une atteinte ischémique jonctionnelle. Abstract Background and Purpose -Thalamic infarcts have traditionally been classified into 4 territories: anterior, paramedian, inferolateral, and posterior. The purpose of this study was to review this classical versus variant distribution in patients with thalamic stroke. Methods - We reviewed all patients with a first clinical stroke included in the Lausanne Stroke Registry between 1990 and 2002. Among 71 patients with an acute stroke isolated to the thalamus confirmed by MRI, we selected all patients with lesions outside the classical territories and studied their clinical, etiological, and radiological features. Results - A total of 21 patients (30% of all thalamic stroke patients) showed infarction outside the classical territories, allowing us to delineate 3 variant distributions: (1) Anteromedian territory (9 patients [13%]) involving anterior and paramedian territories, with predominantly cognitive impairment, including executive dysfunction, anterograde amnesia, and aphasia in left-sided or bilateral lesions. The most frequent stroke mechanism was cardiac embolism. (2) Central territory (4 patients [6%]), with lesions on the central part of the thalamus, resulting in a variety of neurological and neuropsychological signs, reflecting the involvement of several adjacent structures. Microangiopathy was the most frequent etiology. (3) Posterolateral territory (8 patients [11%]), involving inferolateral and posterior territories, with hemihypesthesia as the most frequent manifestation, followed by hemiataxia, executive dysfunction, and aphasia in left-sided lesions. Artery-to-artery embolism and microangiopathy were the main stroke mechanisms. Conclusions - We describe 3 variant topographic patterns of thalamic infarction with distinct manifestations and etiologies. We postulate that these infarcts are the result of a variation in thalamic arterial supply or reflect borderzone ischemia.

Development of an activity index for adult eosinophilic esophagitis: international experts propose dysphagia, withish exudates on endoscopy and peripheral eosinophilia as items with closest association to EoE activity

Background and Aims: Eosinophilic Esophagitis (EoE) is reported with increasing frequency over the last two decades. However, it is still unknown whether this reflects a true increase in incidence or just an increased awareness by gastroenterologists. Therefore, we evaluated the incidence and cumulative prevalence of EoE in Olten county over the last 20 years. Methods: Olten county is an area of approximately 91,000 inhabitants without pronounced demographic changes in the last two decades. EoE evaluation is based upon two gastroenterology centers and one pathology center. No public programs for increased EoE awareness were implemented in this region. All EoE patients diagnosed from 1989 to 2009 were entered prospectively into the Olten county database. Results: Fourty-six patients (76% males, mean age 41±16 yrs) were diagnosed with EoE from 1989 to 2009. Ninety-four percent presented with dysphagia. In 70% of the patients concomitant allergies were found. The number of upper endoscopies per year was stable during the entire observation period. An average annual incidence rate of 2/100,000 was found (range 0-8) with a marked increase in the period from 2001 to 2009. A current cumulative EoE prevalence of 43/100,000 inhabitants was calculated. The mean diagnostic delay (time from first symptoms to diagnosis) was 4.3 years from 1989 to 1998 and 4.8 years from 1999 to 2009. Conclusions: Over the last 20 years, a significant increase in EoE incidence was found in a stable indicator region of Switzerland. The constant rate of upper endoscopies, the constant diagnostic delay, as well as the lack of EoE awareness programs in Olten county indicate a true increase in EoE incidence.

Aging preferentially affects molecular pathways implicated in development and disease of myelinating glial cells

The central and peripheral nervous systems are involved in multiple age-dependent neurological deficits that are often attributed to alterations in function of myelinating glial cells. However, the molecular events that underlie the age-related decline of glial cell function are unknown. We used Schwann cells as a model to study biological processes affected in glial cells by aging. We comprehensively profiled gene expression of the Schwann cellrich mouse sciatic nerve throughout life, from day of birth until senescence (840 days of age). We combined the aging data with the microarray transcriptional data obtained using nerves isolated from Schwann cell-specific neuropathy-inducing mutants MPZCre/+/Lpin1fE2−3/fE2−3 , MPZCre/+/ScapfE1/fE1 and Pmp22-null mice. The majority of age related transcripts were also affected in the analyzed mouse models of neuropathy (54.4%) and in development (59.5%) indicating a high level of overlapping in implicated molecular pathways. We observed that compared to peripheral nerve development, dynamically changing expression profiles in aging have opposite (anticorrelated) orientation while they copy the orientation of transcriptional changes observed in analyzed neuropathy models. Subsequent clustering and biological annotation of dynamically changing transcripts revealed that the processes most significantly deregulated in aging include inflammatory/immune response and lipid biosynthesis/metabolism. Importantly, the changes in these pathways were also observed in myelinated oligodendrocyte-rich optic nerves of aged mice, albeit with lower magnitude. This observation suggests that similar biological processes are affected in aging glial cells in central and peripheral nervous systems, however with different dynamics. Our data, which provide the first comprehensive comparison of molecular changes in glial cells in three distinct biological conditions comprising development, aging and disease, provide not only a new inside into the molecular alterations underlying neural system aging but also identify target pathways for potential therapeutic approaches to prevent or delay complications associated with age-related and inherited forms of neuropathies. *Current address: Department of Physiology, UCSF, San Francisco, CA, USA.

The recent decline in mortality from Hodgkin lymphomas in central and eastern Europe

BACKGROUND: Hodgkin lymphoma (HL) is a largely curable disease and its mortality had steadily declined in western Europe since the late 1960s. Only modest declines were, however, observed in central/eastern Europe. MATERIALS AND METHODS: We updated trends in mortality from HL in various European areas up to 2004 and analyzed patterns in incidence for selected European countries providing national data. RESULTS: In most western European countries, HL mortality continued to steadily decline up to the mid 2000s. More recent reductions were also observed in eastern European countries. Overall, mortality from HL declined from 1.17/100,000 (age-standardized, world population) in 1980-1989 to 1.42/100,000 in 2000-2004 in men from the 15 member states of the European Union (EU) from western and northern Europe. In the EU 10 accession countries of central and eastern Europe, male mortality from HL was 1.42/100,000 in 1980-1984, 1.32 in 1990-1994, and declined to 0.76 in 2000-2004. Similar trends were observed in women. No consistent patterns were found for HL incidence. CONCLUSIONS: The present work confirms the persistent declines in HL mortality in western European countries, and shows favorable patterns over more recent calendar years in central/eastern ones, where rates, however, are still at levels observed in western Europe in the early 1990s.

Natural aphrodisiacs: studies of commercially-available herbal recipes, and phytochemical investigation of "Erythroxylum vacciniifolium" Mart. (Erythroxylaceae) from Brazil

De tout temps, hommes et femmes ont cherché par tous les moyens à développer, préserver ou recouvrer leurs propres capacités sexuelles mais également à stimuler le désir du partenaire. L?utilisation d?aphrodisiaques naturels a été l?un des recours les plus répandus. De nos jours, la commercialisation de nouvelles "love drugs" de synthèse, e.g. Viagra®, Cialis®, Levitra®, a remis au goût du jour les aphrodisiaques classiques et à relancer la recherche sur des molécules nouvelles. La pratique croissante de l?automédication, le matraquage publicitaire sur les aphrodisiaques naturels, la prolifération sur le marché de compléments alimentaires non contrôlés et l?absence de véritable législation accroissent les risques qui pèsent sur la santé publique. Dans le but d?évaluer les risques potentiels sur le consommateur de produits aphrodisiaques commercialisés, le développement et la validation d?une méthode rapide d?analyse qualitative et quantitative de la yohimbine dans ces préparations du marché sont exposés dans la première partie de ce travail. La yohimbine est un antagoniste ?2-adrénocepteur du système nerveux central et périphérique, elle est employée depuis plus d?un siècle dans le traitement des dysfonctionnements érectiles. Cette méthode analytique utilise la chromatographie liquide couplée à l?ultraviolet et à la spectrométrie de masse (LC-UV-MS) et au total, vingt préparations aphrodisiaques ont été étudiées. La dose journalière de yohimbine mesurée s?est révélée très variable selon les produits puisqu?elle varie de 1.32 à 23.16 mg. La seconde partie de ce travail concerne l?étude phytochimique et pharmacologique d?Erythroxylum vacciniifolium Mart. (Erythroxylaceae), une plante, appelée localement catuaba, utilisée dans la médecine traditionnelle brésilienne comme tonique et aphrodisiaque. Dans un premier temps, l?extrait alcaloïdique a été analysé par chromatographie liquide haute performance (HPLC) couplée soit à un détecteur UV à barrette d?iode (LC-UV-DAD), soit à un spectromètre de masse (LC-MS), ou soit à un spectromètre de résonance magnétique nucléaire (LC-RMN). L?interprétation de ces données spectrales enregistrées en ligne a permis d?obtenir des informations structurales et d?identifier partiellement près de 24 alcaloïdes appartenant à la classe des tropanes et potentiellement originaux. Par des méthodes classiques de chromatographie liquide sur l?extrait alcaloïdique de la plante, dix sept tropanes nouveaux ont ensuite été isolés dont les catuabines et leurs dérivés, et les vaccinines. Tous ces composés sont des tropane-diols ou triols estérifiés par au moins un groupe acide 1-méthyl-1H-pyrrole-2-carboxylique. Un de ces composés a été identifié comme un tropane N-oxyde. Toutes les structures ont été déterminées par spectrométrie de masse haute résolution et spectroscopie RMN multi-dimensionnelle. Parmi les nombreux tests biologiques réalisés sur ces tropanes, seuls les tests de cytotoxicité se sont révélés faiblement positifs pour certains de ces composés.<br/><br/>Throughout the ages, men and women have incessantly pursued every means to increase, preserve or recapture their sexual capacity, or to stimulate the sexual desire of selected individuals. One of the most recurrent methods has been the use of natural aphrodisiacs. Nowadays, the commercialization of new synthetic "love drugs", e.g. Viagra®, Cialis® and Levitra®, has fascinated the public interest and has led to a reassessment of classical aphrodisiacs and to the search for new ones. The practice of self-medication by an increasing number of patients, the incessant aggressive advertising of these herbal aphrodisiacs, the invasion of the medicinal market with uncontrolled dietary supplements and the absence of real directives amplifies the potential health hazards to the community. In order to evaluate the possible risks of commercialized aphrodisiac products on consumer health, the development and validation of a rapid qualitative and quantitative method for the analysis of yohimbine in these products, is reported in the first part of the present work. Yohimbine, a pharmacologically well-characterized ?2-adrenoceptor antagonist with activity in the central and peripheral nervous system, has been used for over a century in the treatment of erectile dysfunction. The analytical method is based on liquid chromatography coupled with ultraviolet and mass spectrometry (LC-UV-MS) and in total, 20 commercially-available aphrodisiac preparations were analyzed. The amount of yohimbine measured and expressed as the maximal dose per day suggested on product labels ranged from 1.32 to 23.16 mg. The second part of this work involved the phytochemical and pharmacological investigation of Erythroxylum vacciniifolium Mart. (Erythroxylaceae), a plant used in Brazilian traditional medicine as an aphrodisiac and tonic, and locally known as catuaba. With the aim of obtaining preliminary structure information on-line, the alkaloid extract was analyzed by high performance liquid chromatography (HPLC) coupled to diode array UV detection (LC-UVDAD), to mass spectrometry (LC-MS) and to nuclear magnetic resonance spectroscopy (LCNMR). Interpretation of on-line spectroscopic data led to structure elucidation and partial identification of 24 potentially original alkaloids bearing the same tropane skeleton. Seventeen new tropane alkaloids were then isolated from the alkaloid extract of the plant, including catuabines D to I, their derivatives and vaccinines A and B. All compounds were elucidated as tropane-diol or -triol alkaloids esterified by at least one 1-methyl-1H-pyrrole-2-carboxylic acid. One of the isolated compounds was identified as a tropane alkaloid N-oxide. Their structures were determined by high resolution mass spectrometry and multi-dimensional NMR spectroscopy. Among the numerous bioassays undertaken, only the cytotoxicity tests exhibited a weak positive activity of certain compounds.

Aging preferentially affects molecular pathways implicated in development and disease of myelinating glial cells

The central and peripheral nervous systems are involved in multiple agedependent neurological deficits that are often attributed to alterations in function of myelinating glial cells. However, the molecular events that underlie the age-related decline of glial cell function are unknown. We used Schwann cells as a model to study biological processes affected in glial cells by aging. We comprehensively profiled gene expression of the Schwann cell-rich mouse sciatic nerve throughout life, from day of birth until senescence (840 days of age). We combined the aging data with the microarray transcriptional data obtained using nerves isolated from Schwann cell-specific neuropathy-inducing mutants MPZCre/þ/Lpin1fE2-3/fE2-3, MPZCre/þ/ScapfE1/fE1 and Pmp22-null mice. A majority of age related transcripts were also affected in the analyzed mouse models of neuropathy (54.4%) and in development (59.5%) indicating a high level of overlapping in implicated molecular pathways. We observed that compared to peripheral nerve development, dynamically changing expression profiles in aging have opposite (anticorrelated) orientation while they copy the orientation of transcriptional changes observed in analyzed neuropathy models. Subsequent clustering and biological annotation of dynamically changing transcripts revealed that the processes most significantly deregulated in aging include inflammatory/ immune response and lipid biosynthesis/metabolism. Importantly, the changes in these pathways were also observed in myelinated oligodendrocyte- rich optic nerves of aged mice, albeit with lower magnitude. This observation suggests that similar biological processes are affected in aging glial cells in central and peripheral nervous systems, however with different dynamics. Our data, which provide the first comprehensive comparison of molecular changes in glial cells in three distinct biological conditions comprising development, aging and disease, provide not only a new inside into the molecular alterations underlying neural system aging but also identify target pathways for potential therapeutical approaches to prevent or delay complications associated with age-related and inherited forms of neuropathies.

Between Immunology And Tolerance: Controlling Immune Responses Employing Tolerogenic Dendritic Cells

Dendritic cells (DCs) are the most efficient antigen presenting cells, they provide co-stimulation, are able to secrete various proinflammatory cytokines and therefore play a pivotal role in shaping adaptive immune responses. Moreover, they are important for the promotion and maintenance of central and peripheral tolerance through several mechanisms like the induction of anergy or apoptosis in effector T cells or by promoting regulatory T cells. The murine CD8α+ (MuTu) dendritic cell line was previously derived and described in our laboratory. The MuTu cell line has been shown to maintain phenotypical and functional characteristics of endogenous CD8α+ DCs. They are able to cross-present exogenous antigens to CD8+ T cells and produce interleukin (IL-) 12 upon engagement of Toll like receptors. The cell line constitutes an infinite source of homogenous, phenotypically well-defined dendritic cells. This allows us to investigate the role and potential of specific molecules in the induction as well as regulation of immune responses by DCs in a rational and standardized way. In a first project the MuTu dendritic cell line was transduced in order to stably express the immunosuppressive molecules IL-10, IL-35 or the active form of TGF-β (termed IL-10+DC, IL-35+DC or actTGFβ+DC). We investigated the capability of these potentially suppressive or tolerogenic dendritic cell lines to induce immune tolerance and explore the mechanisms behind tolerance induction. The expression of TGF-β by the DC line did not affect the phenotype of the DCs itself. In contrast, IL-10+ and IL-35+DCs were found to exhibit lower expression of co-stimulatory molecules and MHC class I and II, as well as reduced secretion of pro-inflammatory cytokines upon activation. In vitro co-culture with IL-35+, IL10+ or active TGFβ+ DCs interfered with function and proliferation of CD4+ and CD8+ T cells. Furthermore, IL-35 and active TGF-β expressing DC lines induced regulatory phenotype on CD4+ T cells in vitro without or with expression of Foxp3, respectively. In different murine cancer models, vaccination with IL-35 or active TGF-β expressing DCs resulted in faster tumor growth. Interestingly, accelerated tumor growth could be observed when IL-35-expressing DCs were injected into T cell-deficient RAG-/- mice. IL-10expressing DCs however, were found to rather delay tumor growth. Besides the mentioned autocrine effects of IL-35 expression on the DC line itself, we surprisingly observed that the expression of IL-35 or the addition of IL-35 containing medium enhances neutrophil survival and induces proliferation of endothelial cells. Our findings indicate that the cytokine IL-35 might not only be a potent regulator of adaptive immune responses, but it also implies IL-35 to mediate diverse effects on an array of cellular targets. This abilities make IL-35 a promising target molecule not only for the treatment of auto-inflammatory disease but also to improve anti-cancer immunotherapies. Indeed, by applying active TGFβ+ in murine autoimmune encephalitis we were able to completely inhibit the development of the disease, whereas IL-35+DCs reduced disease incidence and severity. Furthermore, the preventive transfer of IL-35+DCs delayed rejection of transplanted skin to the same extend as the combination of IL-10/actTGF-β expressing DCs. Thus, the expression of a single tolerogenic molecule can be sufficient to interfere with the adequate activation and function of dendritic cells and of co-cultured T lymphocytes. The respective mechanisms of tolerance induction seem to be different for each of the investigated molecule. The application of a combination of multiple tolerogenic molecules might therefore evoke synergistic effects in order to overcome (auto-) immunity. In a second project we tried to improve the immunogenicity of dendritic cell-based cancer vaccines using two different approaches. First, the C57BL/6 derived MuTu dendritic cell line was genetically modified in order to express the MHC class I molecule H-2Kd. We hypothesized that the expression of BALB/c specific MHC class I haplotype (H-2Kd) should allow the priming of tumor-specific CD8+ T cells by the otherwise allogeneic dendritic cells. At the same time, the transfer of these H-2Kd+ DCs into BALB/c mice was thought to evoke a strong inflammatory environment that might act as an "adjuvant", helping to overcome tumor induced immune suppression. Using this so called "semi-allogeneic" vaccination approach, we could demonstrate that the delivery of tumor lysate pulsed H-2Kd+ DCs significantly delayed tumor growth when compared to autologous or allogeneic vaccination. However, we were not able to coherently elucidate the cellular mechanisms underlying the observed effect. Second, we generated MuTu DC lines which stably express the pro-inflammatory cytokines IL-2, IL-12 or IL-15. We investigated whether the combination of DC vaccination and local delivery of pro-inflammatory cytokines might enhance tumor specific T cell responses. Indeed, we observed an enhanced T cell proliferation and activation when they were cocultured in vitro with IL-12 or IL-2-expressing DCs. But unfortunately we could not observe a beneficial or even synergistic impact on tumor development when cytokine delivery was combined with semi-allogeneic DC vaccination.

Comparison of electrical nerve stimulation, electrical muscle stimulation and magnetic nerve stimulation to assess the neuromuscular function of the plantar flexor muscles.

INTRODUCTION: As it might lead to less discomfort, magnetic nerve stimulation (MNS) is increasingly used as an alternative to electrical stimulation methods. Yet, MNS and electrical nerve stimulation (ENS) and electrical muscle stimulation (EMS) have not been formally compared for the evaluation of plantar flexor neuromuscular function. METHODS: We quantified plantar flexor neuromuscular function with ENS, EMS and MNS in 10 volunteers in fresh and fatigued muscles. Central alterations were assessed through changes in voluntary activation level (VAL) and peripheral function through changes in M-wave, twitch and doublet (PS100) amplitudes. Discomfort associated with 100-Hz paired stimuli delivered with each method was evaluated on a 10-cm visual analog scale. RESULTS: VAL, agonist and antagonist M-wave amplitudes and PS100 were similar between the different methods in both fresh and fatigued states. Potentiated peak twitch was lower in EMS compared to ENS, whereas no difference was found between ENS and MNS for any parameter. Discomfort associated with MNS (1.5 ± 1.4 cm) was significantly less compared to ENS (5.5 ± 1.9 cm) and EMS (4.2 ± 2.6 cm) (p < 0.05). CONCLUSION: When PS100 is used to evaluate neuromuscular properties, MNS, EMS and ENS can be used interchangeably for plantar flexor neuromuscular function assessment as they provide similar evaluation of central and peripheral factors in unfatigued and fatigued states. Importantly, electrical current spread to antagonist muscles was similar between the three methods while discomfort from MNS was much less compared to ENS and EMS. MNS may be potentially employed to assess neuromuscular function of plantar flexor muscles in fragile populations.

External Location Factors of Finnish Direct Investment in Central and Eastern European Transitional Economies

Tutkimuksen päätavoitteena oli selvittää suomalaisten suorien investointien maan valintaan vaikuttavia tekijöitä Itä- ja Keski-Euroopan kymmenessä siirtymätaloudessa. Empiirisessä osuudessa tarkasteltiin suomalaisten yritysten tärkeimpiä sijaintitekijöitä alueella ja yrityskohtaisten tekijöiden vaikutusta sijaintitekijöihin. Tutkimuksessa selvitettiin myös yritysten päämotiiveja investoida maihin. Laaditun investointikriteeristön mukaan maat pystyttiin laittamaan paremmuusjärjestykseen suomalaisen investoijan kannalta. Empiirisen osuuden aineisto kerättiin postikyselylomakkeella yrityksiltä, joilla on tai jotka ovat suunnittelemassa investointeja näihin maihin. Tutkimusote oli kvantitatiivinen. Tutkimustulokset osoittavat, että suomalaiset investoijat valitsevat Itä- ja Keski-Euroopan maan investointikohteeksi pääasiassa markkinapotentiaalin ja edullisten kustannusten perusteella. Myös infrastruktuuri vaikuttaa maan valintaan. Eri aloilla toimivien yritysten sijaintitekijöiden painotuksissa havaittiin eroja. Yrityksen koko ja päämotiivi vaikuttivat sijaintitekijöiden painotuksiin. Investointikriteereiden mukaan kaksi parasta investointimaata suomalaisille investoijille ovat Puola ja Viro. Vertailtaessa investointikriteereitä toteutuneisiin investointeihin voidaan todeta, että suomalaiset investoijat eivät ole hyödyntäneet investoinneilla saatavia etuja kaikissa kohdemaissa.

Neuropathogenesis in glutaric aciduria type I and methylmalonic aciduria

Glutaric aciduria type-I (GA-I) and methylmalonic aciduria (MMA-uria) are two neurometabolic diseases manifesting in neonatal period and early childhood. They belong to the group of organic acidurias and are caused by defects in the catabolism of amino acids, leading to massive accumulation of toxic metabolites in the body and severe brain injury. Therapeutic strategies are mainly based on reversing catabolic state during metabolic crisis and dietary protein restriction that both aim to prevent extra production of toxic metabolites. Specific and neuroprotective treatments are missing because the mechanisms of brain damage in these diseases are only poorly understood. The principal objective of my work was to develop in vitro models for both diseases aiming at elucidation of toxic effects of the main metabolites accumulating in GA-I (glutaric acid (GA) and 3-hydroxy glutaric acid (3-OHGA)) and MMA-uria (methylmalonic acid (MMA), propionic acid (PA) and 2-methylcitric acid (2-MCA)) on developing brain cells, and to study the cellular pathways targeted by these deleterious effects in order to find new therapeutic potentials. We used re-aggregated embryonic rat brain cells in organotypic 3D cultures, which were exposed to toxic metabolites at different developing stages of the cultures. In parallel, we studied the cellular localization of the defected enzyme in GA-I, glutaryl-CoA dehydrogenase (GCDH), in the brain and peripheral tissues of rats in adulthood and during embryonic development. GCDH expression: GCDH showed a strong neuronal expression in embryonic central and peripheral nervous system. In the adult brain, GCDH expression was exclusively neuronal with the strongest signal in cerebral cortex and Purkinje cells. GCDH expression was homogenous in embryonic peripheral organs with high levels in intestinal mucosa at late stages. Strong GCDH expression was also observed in liver and intestinal mucosa and with lower intensity in muscles, convoluted renal tubules and renal collecting tubes in adult peripheral organs. GA-I and MMA-uria in vitro models: 3-OHGA (for GA-I) and 2-MCA (for MMA-uria) showed the most deleterious effects at early stages of the cultures with morphological and biochemical alterations and induction of cell death. 3-OHGA and 2-MCA caused astrocytic cell suffering reflected by astrocytic fiber loss and swelling and retardation in oligodendrocytic maturation and/or differentiation. High ammonium increase concomitant with glutamine decrease was observed in these cultures. Neurons were not substantially affected. Our studies revealed that brain-cell generated ammonia may play a role in the neuropathogenesis of these diseases. Thus, developing neuroprotective strategies that target ammonium toxicity in the brain of GA-I and MMA-uria patients might be important according to our findings. -- L'acidurie glutarique de type I (GA-I) et l'acidurie méthylmalonique (MMA-urie) sont deux maladies neurométaboliques se manifestant durant la période néonatale ou la petite enfance, et qui appartiennent aux aciduries organiques. Elles sont causées par des défauts dans le catabolisme des acides aminés, conduisant à une accumulation des métabolites toxiques dans le corps et aussi des lésions cérébrales sévères. Le traitement est limité à une prise en charge d'urgence pendant la crise métabolique et à une diète restreinte en protéines naturelles. Des traitements spécifiques, neuroprotecteurs manquent principalement parce que les mécanismes conduisant aux lésions cérébrales dans ces maladies sont peu connus. L'objectif principal de mon travail était d'élucider les effets toxiques des métabolites accumulés dans GA-I (l'acide glutarique (GA) et l'acide 3-hydroxyglutarique (3-OHGA)) et MMA-uria (l'acide méthylmalonique (MMA), l'acide propionique (PA) et l'acide 2-méthylcitrique(2-MCA) sur les cellules du cerveau ainsi que les voies cellulaires impliquées, dans le but de trouver de potentielles nouvelles stratégies thérapeutiques. Nous avons utilisé un modèle in vitro de cultures 3D de cellules de cerveau d'embryons de rat (en développement) en les exposant aux métabolites toxiques à différents stades de développement des cultures. En parallèle, nous avons étudié la localisation cellulaire de l'enzyme déficiente dans GA-I, la CoA-glutarly déshydrogénase (GCDH), dans le cerveau et les organes périphériques des rats adultes et pendant le développement embryonnaire. L'expression de GCDH: GCDH a montré une expression neuronale forte dans le système nerveux chez l'embryon et le cerveau adulte. L'expression était homogène dans les organes périphériques avec une forte expression dans l'intestin. Les modèles in vitro de GA-I et MMA-uria : 3-OHGA en modèle GA-I et 2-MCA en modèle MMA-uria ont montré les effets délétères les plus importants avec des altérations morphologiques des cellules et biochimiques dans le milieu de culture et l'induction de mort cellulaire non-apoptotique (3-OHGA) ou apoptotique (2-MCA). 3-OHGA et 2-MCA ont provoqué une souffrance astrocytaire avec perte des fibres et gonflement et un retard de maturation et/ou de différentiation des oligodendrocytes. Une augmentation importante d'ammonium avec une diminution concomitante de glutamine a été observée dans les cultures. Les neurones n'étaient pas vraiment affectés. Nos études ont révélé que l'ammonium généré par les cellules cérébrales pourrait jouer un rôle dans la neuropathogenèse de ces deux maladies. Par conséquent, développer des stratégies neuroprotectrices ciblant la toxicité de l'ammonium dans le cerveau des patients atteints de GA-I ou MMA-urie pourrait être très important selon nos résultats.

Structural control on present-day topography of a basement massif: the Central and Eastern Anti-Atlas (Morocco)

The Anti-Atlas basement massif extends South of the High Atlas, and, despite a very mild Cenozoic deformation, its altitude exceeds 1500m in large areas, reaching 3305m in Jbel Sirwa. Structural contours of the present elevation of a polygenic planation surface (the High Erosional surface) and of the base of Cretaceous and Neogene inliers have been performed to characterize the major tectonic structures. Gentle Cenozoic WSW-ENE- and N-Strending folds, of 60 to100km wavelength, reactivate Variscan structures, being the major contributors to the local topography of the Anti-Atlas. Reactivated thrusts of decakilometric to kilometric-scale and E-W trend involving the Neogene rocks exhibit a steep attitude and a small displacement, but they also produce a marked topographic expression. The resulting Cenozoic horizontal shortening along N-S sections across the Anti-Atlas is about 1%. The position of the major anticlinal hinges determines the location of the fluvial divides of the Warzazat basin and the Anti-Atlas, and a structural depression on one of these hinges (Jbel Saghro anticline) allowed the formerly endorheic Warzazat basin to drain southwards. The first Cenozoic structures generating local topography are of pre-mid Miocene age (postdated by 6.7Ma volcanic rocks at the Jbel Saghro), whereas the youngest thrust movements postdate the Pliocene sedimentary and volcanic rocks (involving 2.1Ma volcanic rocks at Jbel Sirwa). In addition to these features, the mean elevation of the Anti-Atlas at the regional scale is also the result of a mantle thermal anomaly reported in previous works for the entire Atlas system.