Why does trehalose not improve autophagy in the SOD1G93A transgenic mouse model of familial ALS?
Amyotrophic lateral sclerosis is one of the major neurodegenerative diseases, causing an ascending paralysis that usually kills the patient within a few years from disease onset. The motor neurons show aggregates of proteins which in approximately 20 % of cases of the familial form contain mutated S...
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| Formato: | H3 |
| Lenguaje: | Inglés sueco |
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SLU/Dept. of Biomedical Sciences and Veterinary Public Health (until 231231)
2015
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| _version_ | 1855571225827344384 |
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| author | Karlsson, Karolina |
| author_browse | Karlsson, Karolina |
| author_facet | Karlsson, Karolina |
| author_sort | Karlsson, Karolina |
| collection | Epsilon Archive for Student Projects |
| description | Amyotrophic lateral sclerosis is one of the major neurodegenerative diseases, causing an ascending paralysis that usually kills the patient within a few years from disease onset. The motor neurons show aggregates of proteins which in approximately 20 % of cases of the familial form contain mutated SOD1 protein.
Trehalose is a disaccharide which has been shown to reduce protein aggregation and increase viability in cell models and alleviate symptoms in animal models of several neurodegenerative diseases associated with protein aggregation. When given orally to the SOD1G93A mouse model of ALS, trehalose failed to slow down the disease progression, which has led to questions about the uptake and distribution of the molecule in this mouse strain.
The aim of this study was to investigate whether significant levels of trehalose reach the central nervous system of the SOD1G93A mouse after oral administration. This was performed by a trehalose assay of the brain of trehalose treated animals. A glucose assay was optimised for use in small samples of brain lysate after the digestion of trehalose into glucose by trehalase, and the difference in glucose concentration before and after digestion represented the trehalose level. No significant differences were detected between digested and undigested samples in trehalose treated mice (46.58±10.39 μg/g wet tissue and 41.86±7.93 μg/g, respectively) or in control mice (60.94±11.39 μg/g wet tissue and 71.58±10.25 μg/g, respectively).
Additionally, the possible effects of trehalose were assessed by histological evaluation of spinal cord sections stained with an antibody directed towards misfolded SOD1 protein. A semi-quantitative method was used to evaluate the number of neurons in different categories of staining and significant differences were only found in the extracellular staining of female mouse spinal cord, where trehalose treated animals showed more intense extracellular staining (p=0.031). Since the study used small groups of animals (n = 4-5 mice), it is possible that the significant result is a false positive, which would support the overall conclusion that trehalose does not reach the central nervous system of the SOD1G93A mouse in significant amounts. |
| format | H3 |
| id | RepoSLU7688 |
| institution | Swedish University of Agricultural Sciences |
| language | Inglés swe |
| publishDate | 2015 |
| publishDateSort | 2015 |
| publisher | SLU/Dept. of Biomedical Sciences and Veterinary Public Health (until 231231) |
| publisherStr | SLU/Dept. of Biomedical Sciences and Veterinary Public Health (until 231231) |
| record_format | eprints |
| spelling | RepoSLU76882015-03-09T10:47:26Z Why does trehalose not improve autophagy in the SOD1G93A transgenic mouse model of familial ALS? Varför ökar inte trehalos autofagi hos musmodellen SOD1G93A av familjär amyotrofisk lateralskleros? Karlsson, Karolina trehalose SOD1 amyotrophic lateral sclerosis ALS autophagy plaque neurodegeneration trehalos SOD1 amyotrofisk lateralskleros ALS autofagi plack neurodegeneration Amyotrophic lateral sclerosis is one of the major neurodegenerative diseases, causing an ascending paralysis that usually kills the patient within a few years from disease onset. The motor neurons show aggregates of proteins which in approximately 20 % of cases of the familial form contain mutated SOD1 protein. Trehalose is a disaccharide which has been shown to reduce protein aggregation and increase viability in cell models and alleviate symptoms in animal models of several neurodegenerative diseases associated with protein aggregation. When given orally to the SOD1G93A mouse model of ALS, trehalose failed to slow down the disease progression, which has led to questions about the uptake and distribution of the molecule in this mouse strain. The aim of this study was to investigate whether significant levels of trehalose reach the central nervous system of the SOD1G93A mouse after oral administration. This was performed by a trehalose assay of the brain of trehalose treated animals. A glucose assay was optimised for use in small samples of brain lysate after the digestion of trehalose into glucose by trehalase, and the difference in glucose concentration before and after digestion represented the trehalose level. No significant differences were detected between digested and undigested samples in trehalose treated mice (46.58±10.39 μg/g wet tissue and 41.86±7.93 μg/g, respectively) or in control mice (60.94±11.39 μg/g wet tissue and 71.58±10.25 μg/g, respectively). Additionally, the possible effects of trehalose were assessed by histological evaluation of spinal cord sections stained with an antibody directed towards misfolded SOD1 protein. A semi-quantitative method was used to evaluate the number of neurons in different categories of staining and significant differences were only found in the extracellular staining of female mouse spinal cord, where trehalose treated animals showed more intense extracellular staining (p=0.031). Since the study used small groups of animals (n = 4-5 mice), it is possible that the significant result is a false positive, which would support the overall conclusion that trehalose does not reach the central nervous system of the SOD1G93A mouse in significant amounts. Amyotrofisk lateralskleros (ALS) är en av de vanligaste neurodegenerativa sjukdomarna hos människor och påverkar övre och nedre motorneuron. Det är en sent insättande progressiv sjukom som oftast yttrar sig initialt genom asymmetrisk muskelsvaghet i ben eller armar eller sluddrande tal och utvecklas till en successivt mer utbredd förlamning. Andningsdepression är den vanligaste dödsorsaken hos ALS-patienter och sker oftast inom 2-5 år efter symptomdebut. Fem till tio procent av ALS-patienter har en släkting med sjukdomen, varför begreppet familjär ALS (fALS) har myntats för denna grupp. Hos 20 % av fALS-patienter är SOD1-genen muterad, men funktionen av detta är oklar. Dock har man sett att modifierade SOD1-protein bildar intracellulära plack, vilka tycks påverka sjukdomsutvecklingen. Transgena musmodeller av ALS har utvecklats genom att inkorporera en muterad variant av SOD1-genen. Syftet med den redovisade studien var att undersöka huruvida oralt intagen trehalos når centrala nervsystemet hos musmodellen SOD1G93A. Bakgrunden till detta är att flera studier av trehalos visat lovande resultat i form av minskad proteinaggregering och ökad överlevnad hos cell- och djurmodeller av flera neurodegenerativa sjukdomar. En tidigare studie utförd på SOD1-möss visade dock inga skillnader på symptomutveckling eller överlevnad vid oralt intag av trehalos. Detta har väckt frågor angående upptag och distribution av trehalos hos dessa möss. Vår frågeställning var huruvida trehalos tas upp från tarmen till centrala nervsystemet, vilket undersöktes genom en mätning av trehaloskoncentrationen i hjärnvävnad från oralt trehalosbehandlade möss. En kommersiell mätmetod för glukoskoncentration optimerades för analys av små volymer av hjärnlysat före och efter digerering av trehalos till glukos. Skillnaden i glukoskoncentration före och efter digerering representerade trehalos-koncentrationen. Inga signifikanta skillnader noterades mellan digererade och odigererade prover hos trehalosbehandlade möss (46,58±10,39 respektive 41,86±7,93 μg/g vävnad) eller kontrolldjur (60,94±11,39 respektive 71,58±10,25 μg/g vävnad). Dessutom studerades eventuella effekter av trehalos genom en immunohistologisk utvärdering av ryggmärgssnitt infärgade med en antikropp riktad mot muterat SOD1-protein. En semikvantitativ metod användes för att utvärdera antalet neuron i olika kategorier av färgning. Signifikanta skillnader mellan trehalosbehandlade och kontrolldjur observerades endast i kategorin extracellulär färgning hos honor, där trehalosbehandlade honors ryggmärg färgades mer intensivt extracellulärt (p=0,031). Då studien var av liten storlek (n = 4-5 möss) är det möjligt att detta enda signifikanta resultat är falskt positivt, vilket skulle stämma överens med den övergripande slutsatsen som indikerar att trehalos vid oral administration inte når CNS hos SOD1G93A-möss i signifikanta mängder. SLU/Dept. of Biomedical Sciences and Veterinary Public Health (until 231231) 2015 H3 eng swe https://stud.epsilon.slu.se/7688/ |
| spellingShingle | trehalose SOD1 amyotrophic lateral sclerosis ALS autophagy plaque neurodegeneration trehalos SOD1 amyotrofisk lateralskleros ALS autofagi plack neurodegeneration Karlsson, Karolina Why does trehalose not improve autophagy in the SOD1G93A transgenic mouse model of familial ALS? |
| title | Why does trehalose not improve autophagy in the SOD1G93A transgenic mouse model of familial ALS? |
| title_full | Why does trehalose not improve autophagy in the SOD1G93A transgenic mouse model of familial ALS? |
| title_fullStr | Why does trehalose not improve autophagy in the SOD1G93A transgenic mouse model of familial ALS? |
| title_full_unstemmed | Why does trehalose not improve autophagy in the SOD1G93A transgenic mouse model of familial ALS? |
| title_short | Why does trehalose not improve autophagy in the SOD1G93A transgenic mouse model of familial ALS? |
| title_sort | why does trehalose not improve autophagy in the sod1g93a transgenic mouse model of familial als? |
| topic | trehalose SOD1 amyotrophic lateral sclerosis ALS autophagy plaque neurodegeneration trehalos SOD1 amyotrofisk lateralskleros ALS autofagi plack neurodegeneration |