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- McLoon, Linda K, et al.
(författare)
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Wnt and Extraocular Muscle Sparing in Amyotrophic Lateral Sclerosis
- 2014
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Ingår i: Investigative Ophthalmology and Visual Science. - : ARVO, The Association for Reserach in Vision and Ophthalmology. - 0146-0404 .- 1552-5783. ; 55:9, s. 5482-5496
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The extraocular muscles (EOM) and their motor neurons are spared in amyotrophic lateral sclerosis (ALS). In limb muscle axon retraction from the neuromuscular junctions occurs early in the disease. Wnts, a conserved family of secreted signaling molecules, play a critical role in neuromuscular junction formation. This is the first study to examine Wnt signaling for its potential involvement in maintenance of normal morphology in EOMs in ALS.METHODS: EOM and limb muscle axons, neuromuscular junctions, and myofibers from control, aging, and ALS patients and the SOD1G93A mouse model of ALS were quantified for their expression of Wnt1, Wnt3a, Wnt5a, Wnt7a, and beta-catenin.RESULTS: All four Wnt isoforms were expressed in most axon profiles in all human EOMs. Significantly fewer were positive for Wnt1, Wnt3a, and Wnt7a in the human limb muscles. Similar differential patterns in Wnt myofiber expression was also seen, except for Wnt7a, where expression was elevated. In the SOD1G93A mouse, all 4 Wnt isoforms were significantly decreased in the neuromuscular junctions at the terminal stage compared to age matched controls. Beta-catenin was activated in a subset of myofibers in EOM and limb muscle in all patients.CONCLUSIONS: The differences in Wnt expression in EOM and limb muscle, particularly at the neuromuscular junction level, suggest that they play a role in the pathophysiology of ALS. Collectively, the data support a role for Wnt signaling in the preservation of the EOM in ALS and their dysregulation and the subsequent development of pathology in the ALS limb muscles.
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- Sjöström, Sara, et al.
(författare)
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Genetic variations in VEGF and VEGFR2 and glioblastoma outcome
- 2011
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Ingår i: Journal of Neuro-Oncology. - Boston : Nijhoff. - 0167-594X .- 1573-7373. ; 104:2, s. 523-527
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Tidskriftsartikel (refereegranskat)abstract
- Vascular endothelial growth factor (VEGF) and its receptors (VEGFR) are central components in the development and progression of glioblastoma. To investigate if genetic variation in VEGF and VEGFR2 is associated with glioblastoma prognosis, we examined blood samples from 154 glioblastoma cases collected in Sweden and Denmark between 2000 and 2004. Seventeen tagging single nucleotide polymorphisms (SNPs) in VEGF and 27 in VEGFR2 were genotyped and analysed, covering 90% of the genetic variability within the genes. In VEGF, we found no SNPs associated with survival. In VEGFR2, we found two SNPs significantly associated to survival, namely rs2071559 and rs12502008. However, these results are likely to be false positives due to multiple testing and could not be confirmed in a separate dataset. Overall, this study provides little evidence that VEGF and VEGFR2 polymorphisms are important for glioblastoma survival.
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- Tjust, Anton E., et al.
(författare)
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Impact of Amyotrophic Lateral Sclerosis on Slow Tonic Myofiber Composition in Human Extraocular Muscles
- 2017
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Ingår i: Investigative Ophthalmology and Visual Science. - : ASSOC RESEARCH VISION OPHTHALMOLOGY INC. - 0146-0404 .- 1552-5783. ; 58:9, s. 3708-3715
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE. To analyze the proportion and cross-sectional area of myofibers containing myosin heavy chain slow-twitch (MyHCI) and myosin heavy chain slow tonic (MyHCsto) in extraocular muscles of autopsied amyotrophic lateral sclerosis (ALS) patients with either spinal or bulbar site of disease onset. METHODS. Whole-muscle cross sections from the middle portion of the medial rectus were labeled with antibodies against MyHCI or MyHCsto and laminin. Myofibers labeled with the MyHC antibodies (MyHCI+sto) and the total number of myofibers were quantified in the orbital and global layer of 6 control individuals and 18 ALS patients. The cross-sectional area of myofibers labeled for either MyHC was quantified in 130 to 472 fibers/individual in the orbital and in 180 to 573 fibers/individual in the global layer of each specimen. RESULTS. The proportion of MyHCI+sto myofibers was significantly smaller in the orbital and global layer of ALS compared to control individuals. MyHCI+sto myofibers were significantly smaller in the global layer than in the orbital layer of ALS, whereas they were of similar size in control subjects. The decreased proportion of MyHCI+sto fibers correlated significantly with the age of death, but not disease duration, in patients who had the bulbar-onset variant of ALS but not in patients with spinal variant. CONCLUSIONS. ALS, regardless of site of onset, involves a loss of myofibers containing MyHCI+sto. Only in bulbar-onset cases did aging seem to play a role in the pathophysiological processes underlying the loss of MyHCI+sto fibers.
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| 5. |
- Tjust, Anton E, et al.
(författare)
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Unaffected motor endplate occupancy in eye muscles of ALS G93A mouse model
- 2012
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Ingår i: Frontiers in bioscience (Scholar edition). - : Frontiers in Bioscience. - 1945-0524. ; 4, s. 1547-1555
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Tidskriftsartikel (refereegranskat)abstract
- Amyotrophic lateral sclerosis (ALS) is a progressive, lethal neurodegenerative disorder characterised by selective loss of motor neurons with accompanying muscle paralysis and respiratory failure. Despite progressive paralysis in trunk and extremity muscles, disturbed eye motility is not a hallmark of ALS. Extraocular muscles (EOMs) of terminal ALS patients show far less morphological signs of disease than their limb muscles. One of the earliest signs of the disease in the transgenic G93A SOD1 mouse model of ALS is loss of motor neuron contact at the neuromuscular junctions (NMJ) in limb muscles. We used immunohistochemistry to identify NMJs and evaluate innervation in EOMs and limb muscles of G93A mice. In G93A limb muscles, loss of axonal contact was seen in 6-82 percent of the NMJs. On the contrary, the degree of endplate occupancy in the EOMs did not differ between transgenic mice and wild-type controls. We propose that EOM-specific properties make these muscles more resistant to the underlying pathophysiological process of ALS and that the EOMs are a useful model to advance our understanding of ALS.
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