AAV9-based gene therapy partially ameliorates the clinical phenotype of a mouse model of Leigh syndrome

Leigh syndrome (LS) is the most common infantile mitochondrial encephalopathy. No treatment is currently available for this condition. Mice lacking $\textit{Ndufs4}$, encoding NADH: ubiquinone oxidoreductase iron-sulfur protein 4 recapitulates the main findings of complex I related LS, including severe multisystemic complex I deficiency and progressive neurodegeneration. In order to develop a gene therapy approach for LS, we used here an AAV2/9 vector carrying the human $\textit{NDUFS4}$ coding sequence (hNDUFS4). We administered AAV2/9-$\textit{hNDUFS4}$ by intravenous (IV) and/or intracerebroventricular (ICV) routes to either newborn or young $\textit{Ndufs4}$$^{-/-}$ mice. We found that IV administration alone was only able to correct the complex I deficiency in peripheral organs, while ICV administration partially corrected the deficiency in the brain. However, both treatments failed to improve the clinical phenotype or to prolong the lifespan of $\textit{Ndufs4}$$^{-/-}$ mice. In contrast, combined IV and ICV treatments resulted, along with increased complex I activity, in the amelioration of the rotarod performance, and in a significant prolongation of the lifespan. Our results indicate that extraneurological organs play an important role in LS pathogenesis, and provide an insight into current limitations of AAV-mediated gene therapy in multisystem disorders. These findings warrant future investigations to develop new vectors able to efficiently target multiple organs.This work was supported by the Core Grant from the MRC, ERC advanced grant FP7- 322424 and NRJ-Institut de France Grant (to MZ) and by the grant [GR-2010-2306- 756] from the Italian Ministry of Health (to CV)

Abstract BOOK SIAART

INTRODUCTION. Dental injury occurres in 0.06 - 0.13 % of general anesthesia procedures re- quiring endotracheal intubation, and it is still a reason of complaint against anesthetists. Maxil- lary central incisors are the most commonly teeth injured.1 In our center claims related to teeth damage after intubation ended with a total reimbursement of 13.000 Euros (2014-2015) and 5 patients (2014 to June 2016) were admitted for cares in Prosthodontics Implant dentistry dept. Dental School - Turin. BUCX et al.2 used a strain gauge based sensor between handle and blade of the laryngoscope to measure forces applied on the maxillary incisors to show that during routine laryngoscopy great forces are exerted on the maxillary incisor teeth with no differences based on the operator experience. OBJECTIVES.The aim of this study is to measure of the forces applied on teeth using a direct laryngoscope or a McGRATH® videolaringoscope. Many authors described how lower force on soft tissue could be applied using a VLS (GlideScope) instead of a standard laryngoscope (P=0.05).3, but no studies have ever been performed involving the use of a force sensor directly applied on teeth. The aim of our study is to measure the forces applied on teeth after the application of a cus- tomized bite (2 mm dental bite) applied on the manikin. Anesthesiologists and anesthesia residents from “Città della Salute e della Scienza”,Turin will be asked to perform 3 intubations using the standard intubation system, and other 3 using McGRATH® videolaringoscope in order to test the intubation forces exerted

Altered Functionality, Morphology, and Vesicular Glutamate Transporter Expression of Cortical Motor Neurons from a Presymptomatic Mouse Model of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a lethal disorder characterized by the gradual degeneration of motor neurons in the cerebrospinal axis. Whether upper motor neuron hyperexcitability, which is a feature of ALS, provokes dysfunction of glutamate metabolism and degeneration of lower motor neurons via an anterograde process is undetermined. To examine whether early changes in upper motor neuron activity occur in association with glutamatergic alterations, we performed whole-cell patch-clamp recordings to analyze excitatory properties of Layer V cortical motor neurons and excitatory postsynaptic currents (EPSCs) in presymptomatic G93A mice modeling familial ALS (fALS). We found that G93A Layer V pyramidal neurons exhibited altered EPSC frequency and rheobase values indicative of their hyperexcitability status. Biocytin loading of these hyperexcitable neurons revealed an expansion of their basal dendrite arborization. Moreover, we detected increased expression levels of the vesicular glutamate transporter 2 in cortical Layer V of G93A mice. Altogether our data show that functional and structural neuronal alterations associate with abnormal glutamatergic activity in motor cortex of presymptomatic G93A mice. These abnormalities, expected to enhance glutamate release and to favor its accumulation in the motor cortex, provide strong support for the view that upper motor neurons are involved early on in the pathogenesis of ALS

Dopamine neuronal loss contributes to memory and reward dysfunction in a model of Alzheimer's disease

Alterations of the dopaminergic (DAergic) system are frequently reported in Alzheimer’s disease (AD) patients and are commonly linked to cognitive and non-cognitive symptoms. However, the cause of DAergic system dysfunction in AD remains to be elucidated. We investigated alterations of the midbrain DAergic system in the Tg2576 mouse model of AD, overexpressing a mutated human amyloid precursor protein (APPswe). Here, we found an age-dependent DAergic neuron loss in the ventral tegmental area (VTA) at pre-plaque stages, although substantia nigra pars compacta (SNpc) DAergic neurons were intact. The selective VTA DAergic neuron degeneration results in lower DA outflow in the hippocampus and nucleus accumbens (NAc) shell. The progression of DAergic cell death correlates with impairments in CA1 synaptic plasticity, memory performance and food reward processing. We conclude that in this mouse model of AD, degeneration of VTA DAergic neurons at pre-plaque stages contributes to memory deficits and dysfunction of reward processing

Altered Functionality, Morphology, and Vesicular Glutamate Transporter Expression of Cortical Motor Neurons from a Presymptomatic Mouse Model of Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis (ALS) is a lethal disorder characterized by the gradual degeneration of motor neurons in the cerebrospinal axis. Whether upper motor neuron hyperexcitability, which is a feature of ALS, provokes dysfunction of glutamate metabolism and degeneration of lower motor neurons via an anterograde process is undetermined. To examine whether early changes in upper motor neuron activity occur in association with glutamatergic alterations, we performed whole-cell patch-clamp recordings to analyze excitatory properties of Layer V cortical motor neurons and excitatory postsynaptic currents (EPSCs) in presymptomatic G93A mice modeling familial ALS (fALS). We found that G93A Layer V pyramidal neurons exhibited altered EPSC frequency and rheobase values indicative of their hyperexcitability status. Biocytin loading of these hyperexcitable neurons revealed an expansion of their basal dendrite arborization. Moreover, we detected increased expression levels of the vesicular glutamate transporter 2 in cortical Layer V of G93A mice. Altogether our data show that functional and structural neuronal alterations associate with abnormal glutamatergic activity in motor cortex of presymptomatic G93A mice. These abnormalities, expected to enhance glutamate release and to favor its accumulation in the motor cortex, provide strong support for the view that upper motor neurons are involved early on in the pathogenesis of ALS

Opa1 overexpression ameliorates the phenotype of two mitochondrial disease mouse models

SummaryIncreased levels of the mitochondria-shaping protein Opa1 improve respiratory chain efficiency and protect from tissue damage, suggesting that it could be an attractive target to counteract mitochondrial dysfunction. Here we show that Opa1 overexpression ameliorates two mouse models of defective mitochondrial bioenergetics. The offspring from crosses of a constitutive knockout for the structural complex I component Ndufs4 (Ndufs4−/−), and of a muscle-specific conditional knockout for the complex IV assembly factor Cox15 (Cox15sm/sm), with Opa1 transgenic (Opa1tg) mice showed improved motor skills and respiratory chain activities compared to the naive, non-Opa1-overexpressing, models. While the amelioration was modest in Ndufs4−/−::Opa1tg mice, correction of cristae ultrastructure and mitochondrial respiration, improvement of motor performance and prolongation of lifespan were remarkable in Cox15sm/sm::Opa1tg mice. Mechanistically, respiratory chain supercomplexes were increased in Cox15sm/sm::Opa1tg mice, and residual monomeric complex IV was stabilized. In conclusion, cristae shape amelioration by controlled Opa1 overexpression improves two mouse models of mitochondrial disease