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ObjectiveTemporal lobe epilepsy (TLE) is characterized by recurrent seizures generated in the limbic system, particularly in the hippocampus. In TLE, recurrent mossy fiber sprouting from dentate gyrus granule cells (DGCs) creates an aberrant epileptogenic network between DGCs which operates via ectopically expressed GluK2/GluK5-containing kainate receptors (KARs). TLE patients are often resistant to anti-seizure medications and suffer significant comorbidities; hence there is an urgent need for novel therapies. Previously we have shown that GluK2 knockout mice are protected from seizures. This study aims at providing evidence that downregulating KARs in the hippocampus using gene therapy reduces chronic epileptic discharges in TLE.MethodsWe combined molecular biology and electrophysiology in rodent models of TLE and in hippocampal slices surgically resected from patients with drug-resistant TLE.ResultsHere we confirmed the translational potential of KAR suppression using a non-selective KAR antagonist that markedly attenuated Interictal-like Epileptiform Discharges (IEDs) in TLE patient-derived hippocampal slices. An adeno-associated virus (AAV) serotype-9 vector expressing anti-grik2miRNA was designed to specifically downregulate GluK2 expression. Direct delivery of AAV9-antigrik2miRNA into the hippocampus of TLE mice led to a marked reduction in seizure activity. Transduction of TLE patient hippocampal slices reduced levels of GluK2 protein and, most importantly, significantly reduced IEDs.InterpretationOur gene silencing strategy to knock down aberrant GluK2 expression demonstrates inhibition of chronic seizure in a mouse TLE model and IEDs in cultured slices derived from TLE patients. These results provide proof-of-concept for a gene therapy approach targeting GluK2 KARs for drug-resistant TLE patients.

The AP-HM tissue bank is the largest one in France regarding some collections, including brain tumors. This collection was used to better characterize some gliomas. In particular because some benign gliomas such as pilocytic astrocytomas (WHO grade I) can be misclassified as malignant ones such as glioblastomas (grade IV) the first aim of our study was to find accurate diagnostic markers. This was done mainly by suppressive substractive hybridization (SSH). This study also provides a restrictive list of genes selectively involved in angiogenesis and invasion, which were highly expressed in GBM. Results were confirmed by real time quantitative RT-PCR in a large cohort of patients. In addition in order to find accurate markers which can predict GBM overall survival (OS) we selected three cohorts of GBM patients with distinctive OS (short survival6 months, long survival18 months and intermediate). Quantification of a series of markers involved in angiogenesis and invasion was done as well as cDNA array analysis.

>Les tumeurs cerebrales primitives malignes font partie des 10 premieres causes de deces par cancer et leur incidence, en augmentation, est estimee a 6-7/100000. Les tumeurs du systeme nerveux central (SNC) posent un probleme de sante publique du fait de la morbidite associee, de la gravite des formes les plus malignes qui demeurent incurables et enfin des populations affectees. En effet, les tumeurs cerebrales touchent particulierement les jeunes et elles constituent le deuxieme cancer chez les 15-34 ans. Le pronostic des gliomes malins est influence par l'âge, l'indice de performance Karnofsky (IK), le Mini-Mental Status (MMS), le type de chirurgie, l'histologie, la dose de radiotherapie delivree, facteurs dont la combinaison definit 6 groupes pronostiques distincts, ou la survie mediane varie de 4,6 a 58,6 mois.

Electron microscopy has a strategic position in the diagnosis of neuromuscular disorders. In muscular fibers, the main abnormalities include vacuoles, inclusion bodies, and myofibrillar disorganization with or without abnormal inclusion material. Vacuolar changes include lipidic and glycogenic storage vacuoles, rimmed vacuoles, and lysosomal and autophagic vacuoles. Accumulation of abnormal inclusion material is found in nemaline myopathy, actinopathies, and hyaline body myopathy. Myofibrillar disorganization involves cores, multiminicores, and myosin chain depletion. Myofibrillar myopathies associate a pathologic pattern of myofibrillar dissolution and ectopic protein expression. They can be divided into two groups: myofibrillar myopathies with multiple expression proteins and myofibrillar myopathies with desmin and alphaB-crystallin expression only. In these two conditions, electron microscopy shows accumulation of a granulofilamentous material immunoreactive for desmin. At least three genes are implicated: desmin, alphaB-crystallin, and myotilin. Lastly, electron microscopy serves to identify changes, pathogenic or not, which are not shown up by light microscopy. Moreover, electron microscopy gives insight on pathophysiological mechanisms and can guide molecular genetics analysis.

Object. Pituitary adenomas are usually benign tumors; however, some behave aggressively and metastasize. Until now, no specific marker of aggressive behavior or malignancy has been found. The polysialylated neural cell adhesion molecule (NCAM), which is highly expressed in embryonic tissues such as the brain and pituitary, is detected in some neuronal and neuroendocrine tumors. Because polysialylation has been implicated in the regulation of cell growth and migration, polysialylated NCAM expression has been considered as a prognostic marker in such tumors. Methods. In the present study, the authors analyzed polysialylated NCAM expression in 82 pituitary tumors from humans: 49 secreting adenomas, 32 nonfunctioning adenomas, and one growth hormone and prolactin—secreting carcinoma associated with acromegaly and spinal and liver metastases. Based on immunohistochemical analyses, the tumors were classified as somatotropic (22 tumors), prolactinoma (14 tumors), corticotropic (17 tumors), and gonadotropic or so-called null cell adenomas (28 tumors). Assessment of polysialylated NCAM was performed using three different methods (immunohistochemical analysis, Western blot analysis, and enzyme-linked immunosorbent assay) with a specific mouse monoclonal immunoglobulin M (Men B) that recognizes polysialic acid on NCAM. Tumoral NCAM expression was also evaluated with the aid of immunohistochemical analysis. Using this method, NCAM and polysialylated NCAM were studied in six healthy pituitaries. In addition, corrrelations were investigated using three statistical methods (chi-square test, nonparametric Mann—Whitney U-test, and principal component analysis) to compare tumoral polysialylated NCAM expression and seven parameters (tumor size and type, intrasphenoidal or cavernous sinus invasion, Ki-67 index, mitoses, and patient age and sex). Neural cell adhesion molecules were expressed in the healthy anterior pituitary and in all tumors. In contrast, polysialylated NCAM was not found in the healthy pituitary gland, but was expressed in 46.3% of typical pituitary tumors and in 85% of the tumors selected as highly aggressive, including one carcinoma and three tumors with histological characteristics that raised suspicion of malignancy. There was no significant correlation between polysialylated NCAM expression and tumor size, tumor type, Ki-67 index, mitoses, or patient age and sex. In contrast, the expression of polysialylated NCAM, which was sensitive to endoneuraminidase-N treatment, was strongly correlated with tumor invasion (p < 0.0001). Conclusions. In pituitary tumors in humans, expression of polysialylated NCAM is strongly related to tumor invasion and confirms the clinical diagnosis of aggressiveness.