An inducible glycogen synthase-1 knockout halts but does not reverse Lafora disease progression in mice
- PMID: 33277363
- PMCID: PMC7857511
- DOI: 10.1074/jbc.RA120.015773
An inducible glycogen synthase-1 knockout halts but does not reverse Lafora disease progression in mice
Abstract
Malstructured glycogen accumulates over time in Lafora disease (LD) and precipitates into Lafora bodies (LBs), leading to neurodegeneration and intractable fatal epilepsy. Constitutive reduction of glycogen synthase-1 (GYS1) activity prevents murine LD, but the effect of GYS1 reduction later in disease course is unknown. Our goal was to knock out Gys1 in laforin (Epm2a)-deficient LD mice after disease onset to determine whether LD can be halted in midcourse, or even reversed. We generated Epm2a-deficient LD mice with tamoxifen-inducible Cre-mediated Gys1 knockout. Tamoxifen was administered at 4 months and disease progression assessed at 12 months. We verified successful knockout at mRNA and protein levels using droplet digital PCR and Western blots. Glycogen determination and periodic acid-Schiff-diastase staining were used to analyze glycogen and LB accumulation. Immunohistochemistry using astrocytic (glial fibrillary acidic protein) and microglial (ionized calcium-binding adapter molecule 1) markers was performed to investigate neuroinflammation. In the disease-relevant organ, the brain, Gys1 mRNA levels were reduced by 85% and GYS1 protein depleted. Glycogen accumulation was halted at the 4-month level, while LB formation and neuroinflammation were significantly, though incompletely, prevented. Skeletal muscle analysis confirmed that Gys1 knockout inhibits glycogen and LB accumulation. However, tamoxifen-independent Cre recombination precluded determination of disease halting or reversal in this tissue. Our study shows that Gys1 knockdown is a powerful means to prevent LD progression, but this approach did not reduce brain glycogen or LBs to levels below those at the time of intervention. These data suggest that endogenous mechanisms to clear brain LBs are absent or, possibly, compromised in laforin-deficient murine LD.
Keywords: Lafora bodies; Lafora disease (Lafora progressive myoclonic epilepsy, MELF); glycogen; glycogen storage disease; glycogen synthase; neurodegenerative disease; neuroinflammation.
Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.
Conflict of interest statement
Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article.
Figures




Similar articles
-
Lithium exacerbates Lafora body formation in the Epm2a-/- Lafora disease mouse model.Neurosci Lett. 2025 May 29;856-858:138250. doi: 10.1016/j.neulet.2025.138250. Epub 2025 Apr 19. Neurosci Lett. 2025. PMID: 40258565
-
Gys1 antisense therapy rescues neuropathological bases of murine Lafora disease.Brain. 2021 Nov 29;144(10):2985-2993. doi: 10.1093/brain/awab194. Brain. 2021. PMID: 33993268 Free PMC article.
-
Glycogen synthase GYS1 overactivation contributes to glycogen insolubility and malto-oligoglucan-associated neurodegenerative disease.EMBO J. 2025 Mar;44(5):1379-1413. doi: 10.1038/s44318-024-00339-3. Epub 2025 Jan 13. EMBO J. 2025. PMID: 39806098 Free PMC article.
-
Lafora disease offers a unique window into neuronal glycogen metabolism.J Biol Chem. 2018 May 11;293(19):7117-7125. doi: 10.1074/jbc.R117.803064. Epub 2018 Feb 26. J Biol Chem. 2018. PMID: 29483193 Free PMC article. Review.
-
Lafora disease.Epileptic Disord. 2016 Sep 1;18(S2):38-62. doi: 10.1684/epd.2016.0842. Epileptic Disord. 2016. PMID: 27702709 Free PMC article. Review.
Cited by
-
Lack of p62 Impairs Glycogen Aggregation and Exacerbates Pathology in a Mouse Model of Myoclonic Epilepsy of Lafora.Mol Neurobiol. 2022 Feb;59(2):1214-1229. doi: 10.1007/s12035-021-02682-6. Epub 2021 Dec 28. Mol Neurobiol. 2022. PMID: 34962634 Free PMC article.
-
Clinicopathologic Dissociation: Robust Lafora Body Accumulation in Malin KO Mice Without Observable Changes in Home-Cage Behavior.J Comp Neurol. 2024 Jul;532(7):e25660. doi: 10.1002/cne.25660. J Comp Neurol. 2024. PMID: 39039998 Free PMC article.
-
miR-140-5p Aggravates Insulin Resistance via Directly Targeting GYS1 and PPP1CC in Insulin-Resistant HepG2 Cells.Diabetes Metab Syndr Obes. 2021 Jun 4;14:2515-2524. doi: 10.2147/DMSO.S304055. eCollection 2021. Diabetes Metab Syndr Obes. 2021. PMID: 34113143 Free PMC article.
-
Large-Scale Protein Production and Activity Assay Protocols for Human Glycogen Synthase-Glycogenin Complex.Methods Mol Biol. 2025;2882:249-277. doi: 10.1007/978-1-0716-4284-9_13. Methods Mol Biol. 2025. PMID: 39992514
-
Glycogen synthase downregulation rescues the amylopectinosis of murine RBCK1 deficiency.Brain. 2022 Jul 29;145(7):2361-2377. doi: 10.1093/brain/awac017. Brain. 2022. PMID: 35084461 Free PMC article.
References
-
- Delgado-Escueta A.V., Ganesh S., Yamakawa K. Advances in the genetics of progressive myoclonus epilepsy. Am. J. Med. Genet. 2001;106:129–138. - PubMed
-
- Minassian B.A. Lafora's disease: towards a clinical, pathologic, and molecular synthesis. Pediatr. Neurol. 2001;25:21–29. - PubMed
-
- Minassian B.A., Lee J.R., Herbrick J.A., Huizenga J., Soder S., Mungall A.J., Dunham I., Gardner R., Fong C.Y., Carpenter S., Jardim L., Satishchandra P., Andermann E., Snead O.C., 3rd, Lopes-Cendes I. Mutations in a gene encoding a novel protein tyrosine phosphatase cause progressive myoclonus epilepsy. Nat. Genet. 1998;20:171–174. - PubMed
-
- Serratosa J.M., Gomez-Garre P., Gallardo M.E., Anta B., de Bernabe D.B., Lindhout D., Augustijn P.B., Tassinari C.A., Malafosse R.M., Topcu M., Grid D., Dravet C., Berkovic S.F., de Cordoba S.R. A novel protein tyrosine phosphatase gene is mutated in progressive myoclonus epilepsy of the Lafora type (EPM2) Hum. Mol. Genet. 1999;8:345–352. - PubMed
-
- Chan E.M., Young E.J., Ianzano L., Munteanu I., Zhao X., Christopoulos C.C., Avanzini G., Elia M., Ackerley C.A., Jovic N.J., Bohlega S., Andermann E., Rouleau G.A., Delgado-Escueta A.V., Minassian B.A. Mutations in NHLRC1 cause progressive myoclonus epilepsy. Nat. Genet. 2003;35:125–127. - PubMed
Publication types
MeSH terms
Substances
Grants and funding
LinkOut - more resources
Full Text Sources
Other Literature Sources
Molecular Biology Databases
Research Materials