FSHD muscular dystrophy Region Gene 1 binds Suv4-20h1 histone methyltransferase and impairs myogenesis

Facioscapulohumeral Muscular Dystrophy (FSHD) is an autosomal dominant myopathy with a strong epigenetic component. It is associated with deletion of a macrosatellite repeat leading to over-expression of the nearby genes. Among them, we focused on FSHD Region Gene 1 (FRG1) since its over-expression in mice, X. laevis and C. elegans leads to muscular dystrophy-like defects, suggesting that FRG1 plays a relevant role in muscle biology. Here we show that, when overexpressed, FRG1 binds and interferes with the activity of the histone methyltransferase Suv4-20h1 both in mammals and Drosophila. Accordingly, FRG1 over-expression or Suv4-20h1 knockdown inhibits myogenesis. Moreover, Suv4-20h KO mice develop muscular dystrophy signs. Finally, we identify the FRG1/Suv4-20h1 target Eid3 as a novel myogenic inhibitor that contributes to the muscle differentiation defects. Our study suggests a novel role of FRG1 as epigenetic regulator of muscle differentiation and indicates that Suv4-20h1 has a gene-specific function in myogenesis

Evaluation of monocytes as carriers for armed oncolytic adenoviruses in murine and Syrian hamster models of cancer

Replication-competent (oncolytic) adenoviruses (OAV) can be adapted as vectors for the delivery of therapeutic genes, with the aim of extending the antitumor effect beyond direct cytolysis. Transgene expression using these vectors is usually intense but short-lived, and repeated administrations are hampered by the rapid appearance of neutralizing antibodies (NAbs). We have studied the performance of monocytes as cell carriers to improve transgene expression in cancer models established in athymic mice and immunocompetent Syrian hamsters. Human and hamster monocytic cell lines (MonoMac6 and HM-1, respectively) were loaded with replication-competent adenovirus-expressing luciferase. Intravenous administration of these cells caused a modest increase in transgene expression in tumor xenografts, but this effect was virtually lost in hamsters. In contrast, intratumoral administration of HM-1 cells allowed repeated cycles of expression and achieved partial protection from NAbs in preimmunized hamsters bearing pancreatic tumors. To explore the therapeutic potential of this approach, HM-1 cells were loaded with a hypoxia-inducible OAV expressing the immunostimulatory cytokine interleukin-12 (IL-12). Three cycles of treatment achieved a significant antitumor effect in the hamster model, and transgene expression was detected following each administration, in contrast with the rapid neutralization of the free virus. We propose monocytes as carriers for multiple intratumoral administrations of armed OAVs

La promozione della salute durante il puerperio.

La promozione della salute durante il puerperio

Are cyclooxygenase-2 and nitric oxide involved in the dyskinesia of Parkinson's disease induced by L-DOPA?

Inflammatory mechanisms are proposed to play a role in l-DOPA-induced dyskinesia. Cyclooxygenase-2 (COX2) contributes to inflammation pathways in the periphery and is constitutively expressed in the central nervous system. Considering that inhibition of nitric oxide (NO) formation attenuates l-DOPA-induced dyskinesia, this study aimed at investigating if a NO synthase (NOS) inhibitor would change COX2 brain expression in animals with l-DOPA-induced dyskinesia. To this aim, male Wistar rats received unilateral 6-hydroxydopamine microinjection into the medial forebrain bundle were treated daily with l-DOPA (21 days) combined with 7-nitroindazole or vehicle. All hemi-Parkinsonian rats receiving l-DOPA showed dyskinesia. They also presented increased neuronal COX2 immunoreactivity in the dopamine-depleted dorsal striatum that was directly correlated with dyskinesia severity. Striatal COX2 co-localized with choline-acetyltransferase, calbindin and DARPP-32 (dopamine-cAMP-regulated phosphoprotein-32), neuronal markers of GABAergic neurons. NOS inhibition prevented l-DOPA-induced dyskinesia and COX2 increased expression in the dorsal striatum. These results suggest that increased COX2 expression after l-DOPA long-term treatment in Parkinsonian-like rats could contribute to the development of dyskinesia

Dynamic Involvement of Striatal NG2-glia in L-DOPA Induced Dyskinesia in Parkinsonian Rats: Effects of Doxycycline

Levo-dihydroxyphenylalanine (L-DOPA) therapy for Parkinson's disease (PD) patients improves motor symptoms, but long-term treatment induces side effects such as abnormal involuntary movements (levodopa-induced dyskinesia – LID). Increasing evidence has linked LID with neuroinflammatory reaction in the striatum involving microglia and astrocytes. The nerve/glial antigen-2 cells (NG2-glia) are recognized as a glial cell whose function in the adult brain is poorly understood. Here, we used immunohistochemistry, confocal microscopy, and western blot to characterize the cellular distribution of NG2-glia in the dorsal striatum of unilaterally 6OHDA-lesioned rats presenting LID. The effect of doxycycline on NG2-glia cells was determined. Dopamine depletion revealed a minor density increase of NG2-glia in the dorsolateral striatum and an activated phenotype. LID development promotes a decrease in NG2-glia cell density and protein level, maintaining the cell-activated feature. Doxycycline antidyskinetic therapy restores the cells to the control density profile. These results indicated the cellular distribution of NG2-glia in the striatum, but the interaction between these cells and other glial types in this model was unanswered and therefore we carried out a double labeling of NG2 and OX-42 (microglia) and GFAP (astrocyte). In LID, there was a decrease in the possible NG2 and OX-42 positive cells interaction, with no effect in the astrocytes. Doxycycline treatment restored the control characteristic. The ability of NG2-glia to regulate their dynamics in response to PD and LID is the first indication of an active link between them. The results suggest that NG2 cells may play important roles other than serving as oligodendrocyte precursor cells.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Fundação de Amparo à Pesquisa do Estado de São Paulo, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Ministerio de Ciencia e Innovación, (grant number 2014/25029-4, 2017/24304-0, 2015/03053-3 and 2018/, 88882.317597/2019-01, PID2019-105218RB-I00)

L-DOPA-induced dyskinesia and neuroinflammation: do microglia and astrocytes play a role?

In Parkinson's disease (PD), l-DOPA therapy leads to the emergence of motor complications including l-DOPA-induced dyskinesia (LID). LID relies on a sequence of pre- and postsynaptic neuronal events, leading to abnormal corticostriatal neurotransmission and maladaptive changes in striatal projection neurons. In recent years, additional non-neuronal mechanisms have been proposed to contribute to LID. Among these mechanisms, considerable attention has been focused on l-DOPA-induced inflammatory responses. Microglia and astrocytes are the main actors in neuroinflammatory responses, and their double role at the interface between immune and neurophysiological responses is starting to be elucidated. Both microglia and astrocytes express a multitude of neurotransmitter receptors and via the release of several soluble molecules modulate synaptic function in neuronal networks. Here we review preclinical and clinical evidence of glial overactivation by l-DOPA, supporting a role of microglia and astrocytes in the development of LID. We propose that in PD, chronically and abnormally activated microglia and astrocytes lead to an aberrant neuron-glia communication, which affect synaptic activity and neuroplasticity contributing to the development of LID