Limits...
Fused in sarcoma (FUS) protein lacking nuclear localization signal (NLS) and major RNA binding motifs triggers proteinopathy and severe motor phenotype in transgenic mice.

Shelkovnikova TA, Peters OM, Deykin AV, Connor-Robson N, Robinson H, Ustyugov AA, Bachurin SO, Ermolkevich TG, Goldman IL, Sadchikova ER, Kovrazhkina EA, Skvortsova VI, Ling SC, Da Cruz S, Parone PA, Buchman VL, Ninkina NN - J. Biol. Chem. (2013)

Bottom Line: Dysfunction of two structurally and functionally related proteins, FUS and TAR DNA-binding protein of 43 kDa (TDP-43), implicated in crucial steps of cellular RNA metabolism can cause amyotrophic lateral sclerosis (ALS) and certain other neurodegenerative diseases.To address this question, we designed a variant of FUS, FUS 1-359, which is predominantly cytoplasmic, highly aggregate-prone, and lacks a region responsible for RNA recognition and binding.These pathological changes cause abrupt development of a severe motor phenotype at the age of 2.5-4.5 months and death of affected animals within several days of onset.

View Article: PubMed Central - PubMed

Affiliation: School of Biosciences, Cardiff University, Cardiff, Wales, United Kingdom.

ABSTRACT
Dysfunction of two structurally and functionally related proteins, FUS and TAR DNA-binding protein of 43 kDa (TDP-43), implicated in crucial steps of cellular RNA metabolism can cause amyotrophic lateral sclerosis (ALS) and certain other neurodegenerative diseases. The proteins are intrinsically aggregate-prone and form non-amyloid inclusions in the affected nervous tissues, but the role of these proteinaceous aggregates in disease onset and progression is still uncertain. To address this question, we designed a variant of FUS, FUS 1-359, which is predominantly cytoplasmic, highly aggregate-prone, and lacks a region responsible for RNA recognition and binding. Expression of FUS 1-359 in neurons of transgenic mice, at a level lower than that of endogenous FUS, triggers FUSopathy associated with severe damage of motor neurons and their axons, neuroinflammatory reaction, and eventual loss of selective motor neuron populations. These pathological changes cause abrupt development of a severe motor phenotype at the age of 2.5-4.5 months and death of affected animals within several days of onset. The pattern of pathology in transgenic FUS 1-359 mice recapitulates several key features of human ALS with the dynamics of the disease progression compressed in line with shorter mouse lifespan. Our data indicate that neuronal FUS aggregation is sufficient to cause ALS-like phenotype in transgenic mice.

Show MeSH

Related in: MedlinePlus

Muscle atrophy, denervation and axonal damage in symptomatic FUS-TG mice.A, prominent atrophy of skeletal muscles at terminal stages of the disease in FUS-TG mice: left and right hind limb gastrocnemius muscles dissected from a transgenic animal with hind limb paralysis when compared with those from a non-transgenic littermate control. B, damaged muscle fibers in gastrocnemius muscle from a paralyzed limb of a FUS-TG animal when compared with normal fibers in gastrocnemius muscle of wild type mouse (hematoxylin and eosin staining). C, representative confocal microscope images of the neuromuscular junctions in gastrocnemius muscles of symptomatic FUS-TG and wild type mice. Endplates were visualized by staining with α-bungarotoxin (α-BTX), and axons and presynapses were visualized with a combination of antibodies against neurofilament-M (NF-M) and synaptophysin (SF). D, representative semithin sections through sciatic nerve of symptomatic (sym) and presymptomatic (presym) FUS-TG and wild type mice stained with toluidine blue. E, reduced total numbers of myelinated fibers in the sciatic nerve of symptomatic but not presymptomatic animals. Bar chart shows mean ± S.E. of fiber number (***, p < 0.001, Mann-Whitney test); the number of nerves analyzed for the group is shown at the bottom of each bar. Scale bars: B, 50 μm; C–E, 30 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3757190&req=5

Figure 5: Muscle atrophy, denervation and axonal damage in symptomatic FUS-TG mice.A, prominent atrophy of skeletal muscles at terminal stages of the disease in FUS-TG mice: left and right hind limb gastrocnemius muscles dissected from a transgenic animal with hind limb paralysis when compared with those from a non-transgenic littermate control. B, damaged muscle fibers in gastrocnemius muscle from a paralyzed limb of a FUS-TG animal when compared with normal fibers in gastrocnemius muscle of wild type mouse (hematoxylin and eosin staining). C, representative confocal microscope images of the neuromuscular junctions in gastrocnemius muscles of symptomatic FUS-TG and wild type mice. Endplates were visualized by staining with α-bungarotoxin (α-BTX), and axons and presynapses were visualized with a combination of antibodies against neurofilament-M (NF-M) and synaptophysin (SF). D, representative semithin sections through sciatic nerve of symptomatic (sym) and presymptomatic (presym) FUS-TG and wild type mice stained with toluidine blue. E, reduced total numbers of myelinated fibers in the sciatic nerve of symptomatic but not presymptomatic animals. Bar chart shows mean ± S.E. of fiber number (***, p < 0.001, Mann-Whitney test); the number of nerves analyzed for the group is shown at the bottom of each bar. Scale bars: B, 50 μm; C–E, 30 μm.

Mentions: Aggregation and deposition of FUS protein are accompanied by severe damage to neurons and their axons. At the symptomatic stage, FUS-TG mice lose approximately half of their spinal motor neurons, whereas the majority of remaining neurons appear shrunken and/or chromatolytic (Fig. 4, A and B). However, the most probable cause of rapidly developing muscle paralysis and muscle atrophy (Fig. 5, A and B) in FUS-TG mice is the disconnection of the motor neuron axons from the muscle endplates (Fig. 5C) because significant neuronal loss and damage of myelinated fibers in peripheral nerves can be observed only at the late, generalized stage of the disease (Fig. 5, D and E).


Fused in sarcoma (FUS) protein lacking nuclear localization signal (NLS) and major RNA binding motifs triggers proteinopathy and severe motor phenotype in transgenic mice.

Shelkovnikova TA, Peters OM, Deykin AV, Connor-Robson N, Robinson H, Ustyugov AA, Bachurin SO, Ermolkevich TG, Goldman IL, Sadchikova ER, Kovrazhkina EA, Skvortsova VI, Ling SC, Da Cruz S, Parone PA, Buchman VL, Ninkina NN - J. Biol. Chem. (2013)

Muscle atrophy, denervation and axonal damage in symptomatic FUS-TG mice.A, prominent atrophy of skeletal muscles at terminal stages of the disease in FUS-TG mice: left and right hind limb gastrocnemius muscles dissected from a transgenic animal with hind limb paralysis when compared with those from a non-transgenic littermate control. B, damaged muscle fibers in gastrocnemius muscle from a paralyzed limb of a FUS-TG animal when compared with normal fibers in gastrocnemius muscle of wild type mouse (hematoxylin and eosin staining). C, representative confocal microscope images of the neuromuscular junctions in gastrocnemius muscles of symptomatic FUS-TG and wild type mice. Endplates were visualized by staining with α-bungarotoxin (α-BTX), and axons and presynapses were visualized with a combination of antibodies against neurofilament-M (NF-M) and synaptophysin (SF). D, representative semithin sections through sciatic nerve of symptomatic (sym) and presymptomatic (presym) FUS-TG and wild type mice stained with toluidine blue. E, reduced total numbers of myelinated fibers in the sciatic nerve of symptomatic but not presymptomatic animals. Bar chart shows mean ± S.E. of fiber number (***, p < 0.001, Mann-Whitney test); the number of nerves analyzed for the group is shown at the bottom of each bar. Scale bars: B, 50 μm; C–E, 30 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3757190&req=5

Figure 5: Muscle atrophy, denervation and axonal damage in symptomatic FUS-TG mice.A, prominent atrophy of skeletal muscles at terminal stages of the disease in FUS-TG mice: left and right hind limb gastrocnemius muscles dissected from a transgenic animal with hind limb paralysis when compared with those from a non-transgenic littermate control. B, damaged muscle fibers in gastrocnemius muscle from a paralyzed limb of a FUS-TG animal when compared with normal fibers in gastrocnemius muscle of wild type mouse (hematoxylin and eosin staining). C, representative confocal microscope images of the neuromuscular junctions in gastrocnemius muscles of symptomatic FUS-TG and wild type mice. Endplates were visualized by staining with α-bungarotoxin (α-BTX), and axons and presynapses were visualized with a combination of antibodies against neurofilament-M (NF-M) and synaptophysin (SF). D, representative semithin sections through sciatic nerve of symptomatic (sym) and presymptomatic (presym) FUS-TG and wild type mice stained with toluidine blue. E, reduced total numbers of myelinated fibers in the sciatic nerve of symptomatic but not presymptomatic animals. Bar chart shows mean ± S.E. of fiber number (***, p < 0.001, Mann-Whitney test); the number of nerves analyzed for the group is shown at the bottom of each bar. Scale bars: B, 50 μm; C–E, 30 μm.
Mentions: Aggregation and deposition of FUS protein are accompanied by severe damage to neurons and their axons. At the symptomatic stage, FUS-TG mice lose approximately half of their spinal motor neurons, whereas the majority of remaining neurons appear shrunken and/or chromatolytic (Fig. 4, A and B). However, the most probable cause of rapidly developing muscle paralysis and muscle atrophy (Fig. 5, A and B) in FUS-TG mice is the disconnection of the motor neuron axons from the muscle endplates (Fig. 5C) because significant neuronal loss and damage of myelinated fibers in peripheral nerves can be observed only at the late, generalized stage of the disease (Fig. 5, D and E).

Bottom Line: Dysfunction of two structurally and functionally related proteins, FUS and TAR DNA-binding protein of 43 kDa (TDP-43), implicated in crucial steps of cellular RNA metabolism can cause amyotrophic lateral sclerosis (ALS) and certain other neurodegenerative diseases.To address this question, we designed a variant of FUS, FUS 1-359, which is predominantly cytoplasmic, highly aggregate-prone, and lacks a region responsible for RNA recognition and binding.These pathological changes cause abrupt development of a severe motor phenotype at the age of 2.5-4.5 months and death of affected animals within several days of onset.

View Article: PubMed Central - PubMed

Affiliation: School of Biosciences, Cardiff University, Cardiff, Wales, United Kingdom.

ABSTRACT
Dysfunction of two structurally and functionally related proteins, FUS and TAR DNA-binding protein of 43 kDa (TDP-43), implicated in crucial steps of cellular RNA metabolism can cause amyotrophic lateral sclerosis (ALS) and certain other neurodegenerative diseases. The proteins are intrinsically aggregate-prone and form non-amyloid inclusions in the affected nervous tissues, but the role of these proteinaceous aggregates in disease onset and progression is still uncertain. To address this question, we designed a variant of FUS, FUS 1-359, which is predominantly cytoplasmic, highly aggregate-prone, and lacks a region responsible for RNA recognition and binding. Expression of FUS 1-359 in neurons of transgenic mice, at a level lower than that of endogenous FUS, triggers FUSopathy associated with severe damage of motor neurons and their axons, neuroinflammatory reaction, and eventual loss of selective motor neuron populations. These pathological changes cause abrupt development of a severe motor phenotype at the age of 2.5-4.5 months and death of affected animals within several days of onset. The pattern of pathology in transgenic FUS 1-359 mice recapitulates several key features of human ALS with the dynamics of the disease progression compressed in line with shorter mouse lifespan. Our data indicate that neuronal FUS aggregation is sufficient to cause ALS-like phenotype in transgenic mice.

Show MeSH
Related in: MedlinePlus