Motor neuron degeneration, severe myopathy and TDP-43 increase in a transgenic pig model of SOD1-linked familiar ALS

Amyotrophic Lateral Sclerosis (ALS) is a neural disorder gradually leading to paralysis of the whole body. Alterations in superoxide dismutase SOD1 gene have been linked with several variants of familial ALS. Here, we investigated a transgenic (Tg) cloned swine model expressing the human pathological hSOD1G93A allele. As in patients, these Tg pigs transmitted the disease to the progeny with an autosomal dominant trait and showed ALS onset from about 27 months of age. Post mortem analysis revealed motor neuron (MN) degeneration, gliosis and hSOD1 protein aggregates in brainstem and spinal cord. Severe skeletal muscle pathology including necrosis and inflammation was observed at the end stage, as well. Remarkably, as in human patients, these Tg pigs showed a quite long presymptomatic phase in which gradually increasing amounts of TDP-43 were detected in peripheral blood mononuclear cells. Thus, this transgenic swine model opens the unique opportunity to investigate ALS biomarkers even before disease onset other than testing novel drugs and possible medical devices

Cellular and Molecular Characterization of Multipolar Map5-Expressing Cells: A Subset of Newly Generated, Stage-Specific Parenchymal Cells in the Mammalian Central Nervous System

<div><p>Although extremely interesting in adult neuro-glio-genesis and promising as an endogenous source for repair, parenchymal progenitors remain largely obscure in their identity and physiology, due to a scarce availability of stage-specific markers. What appears difficult is the distinction between real cell populations and various differentiation stages of the same population. Here we focused on a subset of multipolar, polydendrocyte-like cells (mMap5 cells) expressing the microtubule associated protein 5 (Map5), which is known to be present in most neurons. We characterized the morphology, phenotype, regional distribution, proliferative dynamics, and stage-specific marker expression of these cells in the rabbit and mouse CNS, also assessing their existence in other mammalian species. mMap5 cells were never found to co-express the Ng2 antigen. They appear to be a population of glial cells sharing features but also differences with Ng2+progenitor cells. We show that mMap5 cells are newly generated, postmitotic parenchymal elements of the oligodendroglial lineage, thus being a stage-specific population of polydendrocytes. Finally, we report that the number of mMap5 cells, although reduced within the brain of adult/old animals, can increase in neurodegenerative and traumatic conditions.</p> </div

Map5 distribution in neuronal and glial cells of the rabbit and mouse CNS.

<p>A, Map5 is abundant in most populations of mature neurons (top), neuroblasts occurring in germinal layer-derived neurogenic sites or transitory germinative zones (e.g., rabbit subpial layer, SPL; middle), and in neural progenitors of the brain parenchyma (e.g., rabbit striatum, St; bottom, left). White arrows: clusters of newly generated neuroblasts; white arrowheads: chains of neuroblasts. Newly generated neurons in the cerebellum (Crb) and immature neurons of the piriform cortex (Pir) are generally Map5-negative (green arrowheads; bottom, right), apart from some immature neurons which show low level of Map5 staining (yellow arrowheads). Micrograph in panel A are from peripuberal and adult rabbit tissue, except those marked for mouse. For the Map5 staining on the SVZ ependymal wall, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0063258#pone.0063258.s004" target="_blank">Fig. S4B</a>. B, In addition to its neuronal localization, Map5 decorates a population of multipolar cells with the morphology of synantocytes (see also red arrows in panel A). These cells are better visualized in rabbit than in mouse by immunocytochemistry, since staining in mice reveals to a lesser extent the ramifications of cell processes (schematically showed by drawings on the right; total length of cell processes quantifications in the two mammalian species is showed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0063258#pone.0063258.s002" target="_blank">Fig. S2A</a>). Crb, cerebellum; ML, molecular layer; Cx, cerebral cortex; Cc, corpus callosum; SVZ, subventricular zone; LV, lateral ventricle; Sc, spinal cord; Dg, dentate gyrus of the hippocampus. Scale bars: A, 30 µm; B, 10 µm.</p

Behavior of mMap5 cells under neurodegenerative and traumatic injury conditions in mice.

<p>A, The number of mMap5 is significantly increased in the cerebral cortex (Cx) and corpus callosum (Cc) of APPPS1 trangenic mice. Asterisks, amyloid plaques. B, A slight increase in the amount of mMap5 is detectable after stab wound lesion in the mouse cerebral cortex and corpus callosum. Differences between A and B in the number of mMap5 in WT animals is related to the different ages at which the two lesion models were analysed (12 months for Alzheimer and 3 months for stab wound). Scale bars: Low magnifications, 50 µm; high magnifications, 10 µm.</p