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. 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. Lafora disease (LD) is teenage-onset progressive myoclonus epilepsy that is typically fatal within 10 years of symptom onset (1Delgado-Escueta A.V. Ganesh S. Yamakawa K. Advances in the genetics of progressive myoclonus epilepsy.Am. J. Med. Genet. 2001; 106: 129-138Crossref PubMed Scopus (67) Google Scholar, 2Minassian B.A. Lafora's disease: towards a clinical, pathologic, and molecular synthesis.Pediatr. Neurol. 2001; 25: 21-29Abstract Full Text Full Text PDF PubMed Scopus (138) Google Scholar). LD is caused by autosomal recessive mutations in either EPM2A or NHLRC1 (also known as EPM2B), encoding laforin, a glucan phosphatase, and malin, an E3 ubiquitin ligase, respectively (3Minassian 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 3rd, O.C. Lopes-Cendes I. et al.Mutations in a gene encoding a novel protein tyrosine phosphatase cause progressive myoclonus epilepsy.Nat. Genet. 1998; 20: 171-174Crossref PubMed Scopus (371) Google Scholar, 4Serratosa 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: 345-352Crossref PubMed Scopus (180) Google Scholar, 5Chan 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. et al.Mutations in NHLRC1 cause progressive myoclonus epilepsy.Nat. Genet. 2003; 35: 125-127Crossref PubMed Scopus (224) Google Scholar). The exact roles of both enzymes are unclear. It is, however, established that laforin and malin form a functional complex that regulates glycogen metabolism, with absence of either protein causing formation of malstructured glycogen (6Gentry M.S. Worby C.A. Dixon J.E. Insights into Lafora disease: malin is an E3 ubiquitin ligase that ubiquitinates and promotes the degradation of laforin.Proc. Natl. Acad. Sci. U. S. A. 2005; 102: 8501-8506Crossref PubMed Scopus (167) Google Scholar, 7Sullivan M. Nitschke S. Steup M. Minassian B. Nitschke F. Pathogenesis of Lafora disease: transition of soluble glycogen to insoluble polyglucosan.Int. J. Mol. Sci. 2017; 18: 1743Crossref PubMed Scopus (29) Google Scholar). LD is widely considered a glycogen storage disease (8Nitschke F. Ahonen S.J. Nitschke S. Mitra S. Minassian B.A. Lafora disease - from pathogenesis to treatment strategies.Nat. Rev. Neurol. 2018; 14: 606-617Crossref PubMed Scopus (45) Google Scholar, 9Brewer M.K. Uittenbogaard A. Austin G.L. Segvich D.M. DePaoli-Roach A. Roach P.J. McCarthy J.J. Simmons Z.R. Brandon J.A. Zhou Z. Zeller J. Young L.E.A. Sun R.C. Pauly J.R. Aziz N.M. et al.Targeting pathogenic Lafora bodies in Lafora disease using an antibody-enzyme fusion.Cell Metab. 2019; 30: 689-705.e686Abstract Full Text Full Text PDF PubMed Scopus (26) Google Scholar, 10Tang B. Frasinyuk M.S. Chikwana V.M. Mahalingan K.K. Morgan C.A. Segvich D.M. Bondarenko S.P. Mrug G.P. Wyrebek P. Watt D.S. DePaoli-Roach A.A. Roach P.J. Hurley T.D. Discovery and development of small-molecule inhibitors of glycogen synthase.J. Med. Chem. 2020; 63: 3538-3551Crossref PubMed Scopus (13) Google Scholar, 11Gentry M.S. Afawi Z. Armstrong D.D. Delgado-Escueta A. Goldberg Y.P. Grossman T.R. Guinovart J.J. Harris F. Hurley T.D. Michelucci R. Minassian B.A. Sanz P. Worby C.A. Serratosa J.M. The 5th International Lafora Epilepsy Workshop: basic science elucidating therapeutic options and preparing for therapies in the clinic.Epilepsy Behav. 2020; 103: 106839Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar). The abnormal glycogen molecules precipitate and aggregate to form Lafora bodies (LBs), which continually accumulate, leading to symptom onset and then inexorably worsening neurodegeneration, seizures, and cognitive decline, culminating in vegetative state and death in status epilepticus and related complications (8Nitschke F. Ahonen S.J. Nitschke S. Mitra S. Minassian B.A. Lafora disease - from pathogenesis to treatment strategies.Nat. Rev. Neurol. 2018; 14: 606-617Crossref PubMed Scopus (45) Google Scholar). Both laforin- and malin-deficient LD mouse models (12Ganesh S. Delgado-Escueta A.V. Sakamoto T. Avila M.R. Machado-Salas J. Hoshii Y. Akagi T. Gomi H. Suzuki T. Amano K. Agarwala K.L. Hasegawa Y. Bai D.-S. Ishihara T. Hashikawa T. et al.Targeted disruption of the Epm2a gene causes formation of Lafora inclusion bodies, neurodegeneration, ataxia, myoclonus epilepsy and impaired behavioral response in mice.Hum. Mol. Genet. 2002; 11: 1251-1262Crossref PubMed Scopus (158) Google Scholar, 13DePaoli-Roach A.A. Tagliabracci V.S. Segvich D.M. Meyer C.M. Irimia J.M. Roach P.J. Genetic depletion of the malin E3 ubiquitin ligase in mice leads to Lafora bodies and the accumulation of insoluble laforin.J. Biol. Chem. 2010; 285: 25372-25381Abstract Full Text Full Text PDF PubMed Scopus (87) Google Scholar, 14Turnbull J. Wang P. Girard J.M. Ruggieri A. Wang T.J. Draginov A.G. Kameka A.P. Pencea N. Zhao X. Ackerley C.A. Minassian B.A. Glycogen hyperphosphorylation underlies lafora body formation.Ann. Neurol. 2010; 68: 925-933Crossref PubMed Scopus (72) Google Scholar, 15Criado O. Aguado C. Gayarre J. Duran-Trio L. Garcia-Cabrero A.M. Vernia S. San Millan B. Heredia M. Roma-Mateo C. Mouron S. Juana-Lopez L. Dominguez M. Navarro C. Serratosa J.M. Sanchez M. et al.Lafora bodies and neurological defects in malin-deficient mice correlate with impaired autophagy.Hum. Mol. Genet. 2012; 21: 1521-1533Crossref PubMed Scopus (83) Google Scholar) recapitulate the hallmarks of LD: glycogen accumulation, LB formation, and neuroinflammation (16Turnbull J. DePaoli-Roach A.A. Zhao X. Cortez M.A. Pencea N. Tiberia E. Piliguian M. Roach P.J. Wang P. Ackerley C.A. Minassian B.A. PTG depletion removes Lafora bodies and rescues the fatal epilepsy of Lafora disease.PLoS Genet. 2011; 7e1002037Crossref PubMed Scopus (79) Google Scholar, 17Duran J. Gruart A. Garcia-Rocha M. Delgado-Garcia J.M. Guinovart J.J. Glycogen accumulation underlies neurodegeneration and in Lafora Mol. Genet. PubMed Scopus Google Scholar). In of a for this intractable approach that was to reduce glycogen synthase-1 (GYS1) with glycogen in to prevent glycogen accumulation and LB approach successful with knockout of Gys1 or encoding a protein (also known as in GYS1 Both gene LB formation, neurodegeneration, and of the disease in LD mice (16Turnbull J. DePaoli-Roach A.A. Zhao X. Cortez M.A. Pencea N. Tiberia E. Piliguian M. Roach P.J. Wang P. Ackerley C.A. Minassian B.A. PTG depletion removes Lafora bodies and rescues the fatal epilepsy of Lafora disease.PLoS Genet. 2011; 7e1002037Crossref PubMed Scopus (79) Google Scholar, 17Duran J. Gruart A. Garcia-Rocha M. Delgado-Garcia J.M. Guinovart J.J. Glycogen accumulation underlies neurodegeneration and in Lafora Mol. Genet. PubMed Scopus Google Scholar, B.A. J. J.R. Zhao X. Pencea N. Roach P.J. Ackerley C.A. Minassian B.A. glycogen prevents Lafora disease in a mouse Neurol. Google Scholar, J. J.R. D. Zhao X. Pencea N. Wang P. Ackerley C.A. Minassian B.A. PTG protein depletion rescues malin-deficient Lafora disease in Neurol. PubMed Scopus Google Scholar). These established of that Gys1 for be a therapeutic approach in LD. However, the mice in reduced the as to successful therapeutic of Gys1 be LBs are after disease onset and We generated laforin-deficient mice with Gys1 knockout. We administered at 4 after murine disease and assessed disease progression at 12 months. We glycogen LB accumulation, and neuroinflammation to determine whether LD progression can be halted in midcourse, or even reversed. We generated Gys1 knockout mice to whether Gys1 disease onset to a or even reversal of LD We used mice a with to with Cre to mice in and A of mice was at 4 while the of mice were either or not and then 12 months an of not and but the of used the In to the and and Gys1 knockout mice at 4 and 12 months. These mice Gys1 and Cre but were not to whether Cre-mediated recombination to as 12 mice GYS1 protein knockdown in the brain and muscle which that Cre-mediated Gys1 recombination and knockout was the effect of treatment in the brain of mice and mice the of recombination by Gys1 mRNA that to of Gys1 mRNA were by 85% in both and while mice reduction and Cre at 4 or 12 months mice mice knockdown of GYS1 protein while in GYS1 was in with mice We then whether hallmarks of LD as glycogen and LB accumulation in the brain were halted at the 4-month level, the time of knockout or even reversed. Glycogen determination confirmed an in glycogen accumulation in and mice with in with disease progression was a though not glycogen accumulation in mice in mice with mice in to disease halting or clear in disease progression by mice at 4 months a glycogen as mice at 12 months In glycogen levels were that Gys1 was reduced to prevent of soluble A reduction in soluble glycogen is to be in and can be that the glycogen in mice is insoluble LB a though of bodies astrocytic glucan C. J. L. E. M. J. C. J. E. M. M. Guinovart J.J. glycogen to PubMed Scopus Google Scholar, E. C. G. I. Guinovart J.J. J. J. and of bodies in Lafora 2018; PubMed Scopus Google in mice and LB accumulation in and mice body formation was by Gys1 knockout in LB accumulation was reduced in mice with and mice at 12 though with and mice at 4 months. Gys1 knockout at 4 months did not but LB formation in the In LD the of LBs is in the a A. Epilepsy and the Neurol. PubMed Scopus Google Scholar). However, in to a the LB in the brain, LBs in brain and The are to in the with the that in the a of LB accumulation, be in periodic acid–Schiff–diastase are for LB in and of LD is neuroinflammation M. D. Aguado C. A. M. Roma-Mateo C. E. Sanz P. a novel in Lafora progressive myoclonus epilepsy that with 2020; PubMed Scopus Google Scholar). for fibrillary acidic protein and adapter molecule assessed whether can be halted or by In the and mice did not of Gys1 or and mice or neuroinflammation with mice at 4 months but and by 12 neuroinflammation with LD mice with and levels and and mice and were in the However, was not in or mice at 12 while was but not in In the neuroinflammation was not as as in the and the to determine a in progression of neuroinflammation was to in LD as a neurological LBs in murine and We the muscle to the effect of Gys1 knockout glycogen and LB accumulation disease in the brain, the of recombination by the reduction of Gys1 mRNA with to Gys1 mRNA levels were reduced in mice at 4 Cre in the which was not the in the brain 12 Gys1 mRNA levels were reduced by in and by in culminating in and while mice GYS1 protein levels in mice were as reduced as in mice at 12 months However, a depletion of GYS1 levels in mice at 12 months. at 4 GYS1 levels were reduced in Cre at the protein in to that at the mRNA the effect of and Gys1 knockout muscle and insoluble glycogen the used a established that enzymes to soluble glycogen the insoluble which is not S. S. Ahonen S. Minassian B.A. Nitschke F. of in mouse and Biol. Chem. 2020; Full Text Full Text PDF Scopus Google Scholar). to determine whether in glycogen were to in soluble insoluble or mice an in and insoluble glycogen at 12 while the of insoluble glycogen was of the glycogen at 4 months These are in with the LB accumulation in mice at 12 months as as the LB at 4 with a of but bodies at 4 mice reduced levels of glycogen and an depletion of insoluble that not was disease progression but levels of soluble glycogen were were with The of LB formation in mice to in with the insoluble glycogen However, in the even the soluble glycogen was reduced as glycogen was reduced by with We an of and insoluble glycogen in mice at 12 months in The though not is in with the that a with which are Cre did not or of the that Gys1 knockout the LD muscle however, Cre of disease reversal in this of LD are glycogen accumulation and formation of which are by reduced and F. M.A. Wang P. Zhao X. A.M. L. Juana-Lopez L. P. de Cordoba S. Steup M. Minassian B.A. glycogen not is in Lafora Mol. Med. 2017; PubMed Scopus Google Scholar). glycogen is an a for the LD mouse that glycogen either by Gys1 knockout or by knockout of PTG prevents LB formation, neurodegeneration, and of the disease as impaired (16Turnbull J. DePaoli-Roach A.A. Zhao X. Cortez M.A. Pencea N. Tiberia E. Piliguian M. Roach P.J. Wang P. Ackerley C.A. Minassian B.A. PTG depletion removes Lafora bodies and rescues the fatal epilepsy of Lafora disease.PLoS Genet. 2011; 7e1002037Crossref PubMed Scopus (79) Google Scholar, 17Duran J. Gruart A. Garcia-Rocha M. Delgado-Garcia J.M. Guinovart J.J. Glycogen accumulation underlies neurodegeneration and in Lafora Mol. Genet. PubMed Scopus Google Scholar, B.A. J. J.R. Zhao X. Pencea N. Roach P.J. Ackerley C.A. Minassian B.A. glycogen prevents Lafora disease in a mouse Neurol. Google Scholar, J. J.R. D. Zhao X. Pencea N. Wang P. Ackerley C.A. Minassian B.A. PTG protein depletion rescues malin-deficient Lafora disease in Neurol. PubMed Scopus Google Scholar). to brain glycogen are of and small-molecule inhibitors (8Nitschke F. Ahonen S.J. Nitschke S. Mitra S. Minassian B.A. Lafora disease - from pathogenesis to treatment strategies.Nat. Rev. Neurol. 2018; 14: 606-617Crossref PubMed Scopus (45) Google Scholar). glycogen as a for LD the of to with mutations in either EPM2A or as to gene which development for A is that a is at the time a the knockout mouse models that is to prevent LB formation and the to glycogen is with the in the the effect of the be after disease We generated a using Cre-mediated which to glycogen in laforin-deficient mice at 4 months the LD is We the hallmarks of LD, glycogen accumulation, LB formation, and neuroinflammation. brain glycogen in at 12 months was in mice at 4 months. to a a in disease progression for the the of soluble glycogen in mice to be reduced as as in the glycogen was reduced by Gys1 mRNA and protein levels suggest a of Cre recombination in and that insoluble glycogen in the mice to into that the of glycogen in mice is a of soluble and insoluble In to the of insoluble glycogen at 4 can the of glycogen from the in mice that the of soluble glycogen is not in LD at in the muscle M.A. Nitschke S. Wang P. Zhao X. Wang T. A.M. Lee F. Minassian B.A. Nitschke F. Skeletal muscle glycogen with in mouse models of 2019; Full Text Full Text PDF PubMed Scopus Google Scholar). the glycogen as in mice at 12 of a in disease the in disease progression was not as at the LB in the In the however, a in LB formation which is in with glycogen level, in brain It be that Cre recombination was in the in of the brain as the The Gys1 mRNA and protein levels are an over the brain and not in recombination in brain for in of the brain be in Cre for in in or It that a of LBs in LD mice are in E. C. G. I. Guinovart J.J. J. J. and of bodies in Lafora 2018; PubMed Scopus Google Scholar, C. R. J. M.A. M. Heredia M. Sanz P. in progressive myoclonus epilepsy of Lafora Mol. Genet. 2018; PubMed Scopus Google Scholar). was that the astrocytic and LBs can be in brain E. C. G. I. Guinovart J.J. J. J. and of bodies in Lafora 2018; PubMed Scopus Google Scholar). this is in the and in Cre recombination the of in brain glycogen in is from glycogen in I. J. C. A. O. C. M. Guinovart J.J. an glycogen that to to Metab. PubMed Scopus Google Scholar, G.A. The and in brain and gene PubMed Scopus Google Scholar). These in to reduced GYS1 GYS1 levels are in in and be out that the Gys1 in for is LB formation at a while Gys1 from in be to is a of LD. the disease and and in over time (16Turnbull J. DePaoli-Roach A.A. Zhao X. Cortez M.A. Pencea N. Tiberia E. Piliguian M. Roach P.J. Wang P. Ackerley C.A. Minassian B.A. PTG depletion removes Lafora bodies and rescues the fatal epilepsy of Lafora disease.PLoS Genet. 2011; 7e1002037Crossref PubMed Scopus (79) Google Scholar, I. R. Sanz P. I. in Lafora disease: with disease progression in laforin and malin mouse 2017; PubMed Scopus Google Scholar, A. R. Ganesh S. of and in a mouse for Lafora Mol. Genet. 2017; PubMed Scopus Google Scholar, J. J. Garcia-Rocha M. C. I. L. A. X. E. J.M. Gruart A. Guinovart J.J. and functional with glycogen accumulation in a mouse of Lafora Mol. Med. 2011; PubMed Scopus Google and of the that are in both LD mouse models and are related to and the as to LD M. D. Aguado C. A. M. Roma-Mateo C. E. Sanz P. a novel in Lafora progressive myoclonus epilepsy that with 2020; PubMed Scopus Google Scholar). Our and progression of neuroinflammation in the of in with the LB In the a in LB formation was neuroinflammation in and mice to of neuroinflammation in this brain However, is a epilepsy and in A. Epilepsy and the Neurol. PubMed Scopus Google and data from that the of and is to disease progression, as M. D. Aguado C. A. M. Roma-Mateo C. E. Sanz P. a novel in Lafora progressive myoclonus epilepsy that with 2020; PubMed Scopus Google Scholar, I. R. Sanz P. I. in Lafora disease: with disease progression in laforin and malin mouse 2017; PubMed Scopus Google Scholar). The in this study was the brain as the in LD. However, to Gys1 mouse Cre-mediated recombination in in to the brain Gys1 mRNA and GYS1 protein levels did not Cre The of the Cre mice used in this study Cre in a of S. A.P. recombination in by a tamoxifen-inducible form of a for gene in the Biol. 2002; PubMed Scopus Google and this used mouse of did not inclusion of to of Cre et S. K. C.A. R. C.A. after gene J. Metab. PubMed Scopus Google Scholar) did Cre and a to reduction in mRNA in muscle by 4 months of Cre as the used in this Cre to a are in the to to the this for of Cre Cre is a caused by of Cre in the J. activity of in 2017; PubMed Scopus Google Scholar, M. and of J. 2020; PubMed Scopus Google Scholar). Cre and B. A.M. of for of PubMed Scopus (9) Google Scholar, H. K. I. J.A. K. the that tamoxifen-independent for microglial and gene J. 2020; PubMed Scopus Google Scholar, L. M. A. Z. J. S. T. M. S. analysis of mice for the study of brain a J. 2020; PubMed Scopus Google Scholar) and gene to recombination M. J. A. A Cre mouse shows that recombination is 2001; PubMed Scopus Google Scholar, J. Y. G. recombination as of PubMed Scopus Google Scholar) with Cre the Cre and in mice and the 4-month to Cre In to be that in both and recombination and with the Cre mice used Cre N. H. R. of Cre activity and effect 2020; PubMed Scopus Google Scholar, C. J. C. J. J. at the The Scholar). in the at the of the Cre as as that of the in Cre J. J. S. state with gene and activity in the 2012; PubMed Scopus Google Scholar, M.A. inhibits recombination of the and in PubMed Scopus Google Scholar) and a M. and of J. 2020; PubMed Scopus Google Scholar, M. J. A. A Cre mouse shows that recombination is 2001; PubMed Scopus Google in the both Gys1 be out that a muscle that Cre is a and of using Cre M.A. inhibits recombination of the and in PubMed Scopus Google Scholar, S. J. C. I. Wang Y. R. R. S. Genetic as an development for treatment in PubMed Scopus (13) Google Scholar). The in Cre the brain and muscle in this the of Cre in the Cre in the muscle and reversal of LD in the muscle and an In the months and even to years into the with LD are are that are with the epilepsy. an approach that or disease progression, as in the in the mouse of the be In the with LD are EPM2A and NHLRC1 are in epilepsy gene and study at whether glycogen in of mechanisms as with LB formation clear LBs to that did not a reduction in LBs GYS1 LB mechanisms in the brain to be at in the laforin-deficient mouse treatment for LD and are in (8Nitschke F. Ahonen S.J. Nitschke S. Mitra S. Minassian B.A. Lafora disease - from pathogenesis to treatment strategies.Nat. Rev. Neurol. 2018; 14: 606-617Crossref PubMed Scopus (45) Google Scholar, 11Gentry M.S. Afawi Z. Armstrong D.D. Delgado-Escueta A. Goldberg Y.P. Grossman T.R. Guinovart J.J. Harris F. Hurley T.D. Michelucci R. Minassian B.A. Sanz P. Worby C.A. Serratosa J.M. The 5th International Lafora Epilepsy Workshop: basic science elucidating therapeutic options and preparing for therapies in the clinic.Epilepsy Behav. 2020; 103: 106839Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar). of at GYS1 levels or of that degradation of Gys1 mRNA or of small-molecule inhibitors of A the successful development of small-molecule inhibitors of GYS1 and of GYS1 in B. Frasinyuk M.S. Chikwana V.M. Mahalingan K.K. Morgan C.A. Segvich D.M. Bondarenko S.P. Mrug G.P. Wyrebek P. Watt D.S. DePaoli-Roach A.A. Roach P.J. Hurley T.D. Discovery and development of small-molecule inhibitors of glycogen synthase.J. Med. Chem. 2020; 63: 3538-3551Crossref PubMed Scopus (13) Google Scholar). in to be treatment options for LD. However, in mice to LD, therapies at prevent progression, but not the therapies to be administered in the disease progression with in with disease the in as of to the brain M.K. Uittenbogaard A. Austin G.L. Segvich D.M. DePaoli-Roach A. Roach P.J. McCarthy J.J. Simmons Z.R. Brandon J.A. Zhou Z. Zeller J. Young L.E.A. Sun R.C. Pauly J.R. Aziz N.M. et al.Targeting pathogenic Lafora bodies in Lafora disease using an antibody-enzyme fusion.Cell Metab. 2019; 30: 689-705.e686Abstract Full Text Full Text PDF PubMed Scopus (26) Google be the be to the LB Our that or halting LD progression after LBs is in the LD mouse of LBs was not Our to the of in glycogen

Topics & Concepts