Cerebellar Astrocyte Transduction as Gene Therapy for Megalencephalic Leukoencephalopathy
NEUROTHERAPEUTICS
Authors: Sanchez, Angela; Garcia-Lareu, Belen; Puig, Meritxell; Prat, Esther; Ruberte, Jesus; Chillon, Miguel; Nunes, Virginia; Estevez, Raul; Bosch, Assumpcio
Abstract
Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a rare genetic disorder belonging to the group of vacuolating leukodystrophies. It is characterized by megalencephaly, loss of motor functions, epilepsy, and mild mental decline. In brain biopsies of MLC patients, vacuoles were observed in myelin and in astrocytes surrounding blood vessels. There is no therapy for MLC patients, only supportive treatment. We show here a preclinical gene therapy approach for MLC using the Mlc1 knock-out mouse. An adeno-associated virus coding for human MLC1 under the control of the glial fibrillary acidic protein promoter was injected in the cerebellar subarachnoid space of Mlc1 knock-out and wild-type animals at 2 months of age, before the onset of the disease, as a preventive approach. We also tested a therapeutic strategy by injecting the animals at 5 months, once the histopathological abnormalities are starting, or at 15 months, when they have progressed to a more severe pathology. MLC1 expression in the cerebellum restored the adhesion molecule GlialCAM and the chloride channel ClC-2 localization in Bergmann glia, which both are mislocalized in Mlc1 knock-out model. More importantly, myelin vacuolation was extremely reduced in treated mice at all ages and correlated with the amount of expressed MLC1 in Bergmann glia, indicating not only the preventive potential of this strategy but also its therapeutic capacity. In summary, here we provide the first therapeutic approach for patients affected with MLC. This work may have also implications to treat other diseases affecting motor function such as ataxias.
Chemical looping combustion with nanosize oxygen carrier: a review
INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY
Authors: Akram, W.; Sanjay; Hassan, M. A.
Abstract
This paper reports latest advancement on oxygen carriers (OCs) and effect of particle size from micro- to nanoscale in chemical looping combustion (CLC). CLC is basically a carbon capture and storage technology with the objective to reduce carbon dioxide emission from fossil fuel-based power plants, and it has the potential to reduce the global warming. Attention has been drawn toward utilization of nanosize-based oxygen carrier for bulk application. CLC is a novel technology for combustion of fossil fuels that avoids dilution of carbon dioxide (CO2) with flue gases. Performance of CLC system depends upon redox reactivity and stability of oxygen carrier particles at high operating temperature. Oxides of metals like nickel, iron, copper, and mixed metals have also been discussed. Tendency of discussed nano-OC to agglomerate and stability at high temperature can be addressed by the use of suitable inert support materials. Reactivity of oxygen carrier increases with decreasing particle sizes from micro- to nanosize. Recent developments in nanosized oxygen carriers can be exploited for application. The challenges associated with nanosize oxygen carriers are stabilization and agglomeration at temperature above 600 degrees C. Different techniques have been proposed and investigated to overcome challenges. Various metal/metal oxide pair has been evaluated for its oxygen bearing capacity, stability, and resistance to agglomeration. Stability and agglomeration of nanosize oxygen carrier at temperature above 700 degrees C is an open issue.