Amyotrophic lateral sclerosis (ALS) is a progressive degenerative disorder affecting motoneurons and the SOD1(G93A) transgenic mice are widely employed to study disease physiopathology and therapeutic strategies. Despite the cellular and biochemical evidences of an early motor system dysfunction, the conventional behavioral tests do not detect early motor impairments in SOD1 mouse model. We evaluated early changes in motor behavior of ALS mice by doing the analyses of tail elevation, footprint, automatic recording of motor activities by means of an infrared motion sensor activity system and electrophysiological measurements in male and female wild-type (WT) and SOD1(G93A) mice from postnatal day (P) 20 up to endpoint. The classical evaluations of mortality, weight loss, tremor, rotometer, hanging wire and inclined plane were also employed. There was a late onset (after P90) of the impairments of classical parameters and the outcome varied between genders of ALS mice, being tremor, cumulative survival, weight loss and neurological score about 10 days earlier in male than female ALS mice and also about 20 days earlier in ALS males regarding rotarod and hanging wire performances. While diminution of hindpaw base was 10 days earlier in ALS males (P110) compared to females, the steep length decreased 40 days earlier in ALS females (P60) than ALS males. The automatic analysis of motor impairments showed substantial late changes (after P90) of motility and locomotion in the ALS females, but not in the ALS males. It was surprising that the scores of tail elevation were already decreased in ALS males and females by P40, reaching the minimal values at the endpoint. The electrophysiological analyses showed early changes of measures in the ALS mouse sciatic nerve, i.e., decreased values of amplitude (P40) and nerve conduction velocity (P20), and also an increased latency (P20) reaching maximal level of impairments at the late disease phase. The early changes were not accompanied by reductions of neuronal protein markers of neurofilament 200 and ChAT in the ventral part of the lumbar spinal cord of P20 and P60 ALS mice by means of Western blot technique, despite remarkable decreases of those protein levels in P120 ALS mice. In conclusion, early changes of motor behavior and electrophysiological parameters in ALS mouse model must be taken into attention in the analyses of disease mechanisms and therapeutic effects.

Corticosteroids cause muscle atrophy by acting on proteasomal and lysosomal systems and by affecting pathways related to muscular trophysm, such as the IGF-1/PI-3k/Akt/mTOR. Omega-3 fatty acid (n-3) has been used beneficially to attenuate muscle atrophy linked to sepsis and cachexia; however, its effect on dexamethasone-induced muscle atrophy has not been evaluated. Objectives. We evaluated whether n-3 supplementation could mitigate the development of dexamethasone-induced muscle atrophy. Methods. Two groups of Wistar rats were orally supplemented with n-3 or vehicle solution for 40 days. In the last 10 days, dexamethasone, or saline solution, was administrated establishing four groups: control, dexamethasone, n-3, and dexamethasone + n-3. The cross-sectional areas of muscle fibers, gene expression (MyoD, Myogenin, MuRF-1, and Atrogin-1), and protein expression (Akt, GSK3β, FOXO3a, and mTOR) were assessed. Results. Dexamethasone induced a significant loss in body and muscle weight, atrophy in type 2B fibers, and decreased expression of P-Akt, P-GSK3β, and P-FOXO3a. N-3 supplementation did not attenuate the negative effects of dexamethasone on skeletal muscle; instead, it caused atrophy in type 1, 2A, reduced the expression of Myogenin, and increased the expression of Atrogin-1. Conclusion. Food supplements containing n-3 are usually healthful, but they may potentiate some of the side effects of glucocorticoids.

Early molecular events related to cytoskeleton are poorly described in Amyotrophic Lateral Sclerosis (ALS), especially in the Schwann cell (SC), which offers strong trophic support to motor neurons. Database for Annotation, Visualization and Integrated Discovery (DAVID) tool identified cytoskeleton-related genes by employing the Cellular Component Ontology (CCO) in a large gene profiling of lumbar spinal cord and sciatic nerve of presymptomatic SOD1G93A mice. One and five CCO terms related to cytoskeleton were described from the spinal cord deregulated genes of 40 days (actin cytoskeleton) and 80 days (microtubule cytoskeleton, cytoskeleton part, actin cytoskeleton, neurofilament cytoskeleton, and cytoskeleton) old transgene mice, respectively. Also, four terms were depicted from the deregulated genes of sciatic nerve of 60 days old transgenes (actin cytoskeleton, cytoskeleton part, microtubule cytoskeleton and cytoskeleton). Kif1b was the unique deregulated gene in more than one studied region or presymptomatic age. The expression of Kif1b [quantitative polymerase chain reaction (qPCR)] elevated in the lumbar spinal cord (40 days old) and decreased in the sciatic nerve (60 days old) of presymptomatic ALS mice, results that were in line to microarray findings. Upregulation (24.8 fold) of Kif1b was seen in laser microdissected enriched immunolabeled motor neurons from the spinal cord of 40 days old presymptomatic SOD1G93A mice. Furthermore, Kif1b was dowregulated in the sciatic nerve Schwann cells of presymptomatic ALS mice (60 days old) that were enriched by means of cell microdissection (6.35 fold), cell sorting (3.53 fold), and primary culture (2.70 fold) technologies. The gene regulation of cytoskeleton molecules is an important occurrence in motor neurons and Schwann cells in presymptomatic stages of ALS and may be relevant in the dying back mechanisms of neuronal death. Furthermore, a differential regulation of Kif1b in the spinal cord and sciatic nerve cells emerged as key event in ALS.

Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease that leads to widespread motor neuron death, general palsy and respiratory failure. The most prevalent sporadic ALS form is not genetically inherited. Attempts to translate therapeutic strategies have failed because the described mechanisms of disease are based on animal models carrying specific gene mutations and thus do not address sporadic ALS. In order to achieve a better approach to study the human disease, human induced pluripotent stem cell (hiPSC)-differentiated motor neurons were obtained from motor nerve fibroblasts of sporadic ALS and non-ALS subjects using the STEMCCA Cre-Excisable Constitutive Polycistronic Lentivirus system and submitted to microarray analyses using a whole human genome platform. DAVID analyses of differentially expressed genes identified molecular function and biological process-related genes through Gene Ontology. REVIGO highlighted the related functions mRNA and DNA binding, GTP binding, transcription (co)-repressor activity, lipoprotein receptor binding, synapse organization, intracellular transport, mitotic cell cycle and cell death. KEGG showed pathways associated with Parkinson's disease and oxidative phosphorylation, highlighting iron homeostasis, neurotrophic functions, endosomal trafficking and ERK signaling. The analysis of most dysregulated genes and those representative of the majority of categorized genes indicates a strong association between mitochondrial function and cellular processes possibly related to motor neuron degeneration. In conclusion, iPSC-derived motor neurons from motor nerve fibroblasts of sporadic ALS patients may recapitulate key mechanisms of neurodegeneration and may offer an opportunity for translational investigation of sporadic ALS. Large gene profiling of differentiated motor neurons from sporadic ALS patients highlights mitochondrial participation in the establishment of autonomous mechanisms associated with sporadic ALS.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by loss of motor neurons. Familial ALS is strongly associated to dominant mutations in the gene for Cu/Zn superoxide dismutase (SOD1). Recent evidences point to skeletal muscle as a primary target in the ALS mouse model. Wnt/PI3 K signaling pathways and epithelial-mesenchymal transition (EMT) have important roles in maintenance and repair of skeletal muscle. Wnt/PI3 K pathways and EMT gene expression profile were investigated in gastrocnemius muscle from SOD1(G93A) mouse model and age-paired wild-type control in the presymptomatic ages of 40 and 80 days aiming the early neuromuscular abnormalities that precede motor neuron death in ALS. A customized cDNA microarray platform containing 326 genes of Wnt/PI3 K and EMT was used and results revealed eight up-regulated (Loxl2, Pik4ca, Fzd9, Cul1, Ctnnd1, Snf1lk, Prkx, Dner) and nine down-regulated (Pik3c2a, Ripk4, Id2, C1qdc1, Eif2ak2, Rac3, Cds1, Inppl1, Tbl1x) genes at 40 days, and also one up-regulated (Pik3ca) and five down-regulated (Cd44, Eef2 k, Fzd2, Crebbp, Piki3r1) genes at 80 days. Also, protein-protein interaction networks grown from the differentially expressed genes of 40 and 80 days old mice have identified Grb2 and Src genes in both presymptomatic ages, thus playing a potential central role in the disease mechanisms. mRNA and protein levels for Grb2 and Src were found to be increased in 80 days old ALS mice. Gene expression changes in the skeletal muscle of transgenic ALS mice at presymptomatic periods of disease gave further evidence of early neuromuscular abnormalities that precede motor neuron death. The results were discussed in terms of initial triggering for neuronal degeneration and muscle adaptation to keep function before the onset of symptoms.

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Background Mutations in GRN (progranulin) and MAPT (microtubule-associated protein tau) are among the most frequent causes of monogenic Frontotemporal Dementia (FTD), but data on the frequency of those mutations in regions such as Latin America is still lacking. Objective We aimed to investigate the frequencies of GRN and MAPT mutations in FTD cohorts from two Brazilian dementia research centers, from University of Sao Paulo (USP) and Federal University of Minas Gerais (UFMG) medical schools. Methods We included 76 probands diagnosed with behavioral variant FTD (n=55), semantic variant Primary Progressive Aphasia (PPA) (n=11), or nonfluent variant PPA (n=10). Twenty-five percent of the cohort had at least one relative affected with FTD. Results Mutations in GRN were identified in seven probands, and in MAPT, in two probands. We identified three novel GRN mutations (p.Q130X, p.317Afs*12, and p.K259Afs*23), in patients diagnosed with nfvPPA or bvFTD. Plasma progranulin levels were measured and a cutoff value of 70ng/ml was found with 100% sensitivity and specificity to detect null GRN mutations. Conclusions The frequency of GRN mutations was 9.6% and of MAPT mutations, was 7.1%. Among familial cases of FTD, the frequency of GRN mutations was 31.5%, and of MAPT mutations was 10.5%.