A mutation-independent approach for muscular dystrophy via upregulation of a modifier gene

Kemaladewi, Dwi U.; Bassi, Prabhpreet S; Erwood, Steven; Al-Basha, Dhekra; Gawlik, Kinga I.; Lindsay, Kyle; Hyatt, Elzbieta; Kember, Rebekah; Place, Kara M; Marks, Ray; Durbeej, Madeleine; Prescott, Steven A.; Ivakine, Evgueni A.; Cohn, Ronald D.

doi:10.1038/s41586-019-1430-x

Cited by 107 publications

(92 citation statements)

References 37 publications

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“…For example, overexpression of a functional endogenous copy has the potential to rescue human diseases caused by haploinsufficiency [19]. Alternatively, overexpression of a protein similar to one encoded by a mutant gene could treat human diseases caused by recessive mutations [20]. For example, congenital muscular dystrophy type 1A (MDC1A) is an autosomal recessive disorder caused by mutations in LAMA2 that cause production of nonfunctional laminin-α2.…”

Section: Discussionmentioning

confidence: 99%

“…For example, congenital muscular dystrophy type 1A (MDC1A) is an autosomal recessive disorder caused by mutations in LAMA2 that cause production of nonfunctional laminin-α2. Viral overexpression of Lama1, which encodes a similar protein, in a mouse model of MDC1A improved disease symptoms and slowed progression [20]. Thus, the development of a system that yields robust activation and yet is small enough to be cloned into a virus vector, is an important priority for therapeutic applications.…”

Section: Discussionmentioning

confidence: 99%

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Synergistic Upregulation of Target Genes by TET1 and VP64 in the dCas9–SunTag Platform

Morita

Horii

Kimura

et al. 2020

IJMS

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Overexpression of a gene of interest is a general approach used in both basic research and therapeutic applications. However, the conventional approach involving overexpression of exogenous genes has difficulty achieving complete genome coverage, and is also limited by the cloning capacity of viral vectors. Therefore, an alternative approach would be to drive the expression of an endogenous gene using an artificial transcriptional activator. Fusion proteins of dCas9 and a transcription activation domain, such as dCas9–VP64, are widely used for activation of endogenous genes. However, when using a single sgRNA, the activation range is low. Consequently, tiling of several sgRNAs is required for robust transcriptional activation. Here we describe the screening of factors that exhibit the best synergistic activation of gene expression with TET1 in the dCas9–SunTag format. All seven factors examined showed some synergy with TET1. Among them, VP64 gave the best results. Thus, simultaneous tethering of VP64 and TET1 to a target gene using an optimized dCas9–SunTag format synergistically activates gene expression using a single sgRNA.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Synergistic Upregulation of Target Genes by TET1 and VP64 in the dCas9–SunTag Platform

Morita

Horii

Kimura

et al. 2020

IJMS

View full text Add to dashboard Cite

show abstract

“…Finally, strategies such as AAV-mediated expression of mini-Agrin (Moll et al, 2001), CRISPR/CAS9-mediated over expression of laminin-alpha1 (Kemaladewi et al, 2019), or treatment with recombinant laminin-111 (Rooney et al, 2012) would be logical choices to compensate for the missing laminin-alpha2. LAMA1 is similar to LAMA2, thus overexpression would compensate for lack of LAMA2 function while minimizing the risk of an immune response to laminin-111.…”

Section: Therapeutic Strategies Targeting Fibrosismentioning

confidence: 99%

Fibrogenesis in LAMA2-Related Muscular Dystrophy Is a Central Tenet of Disease Etiology

Accorsi

Cramer

Girgenrath

2020

Front. Mol. Neurosci.

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LAMA2-related congenital muscular dystrophy, also known as MDC1A, is caused by loss-of-function mutations in the alpha2 chain of Laminin-211. Loss of this protein interrupts the connection between the muscle cell and its extracellular environment and results in an aggressive, congenital-onset muscular dystrophy characterized by severe hypotonia, lack of independent ambulation, and early mortality driven by respiratory complications and/or failure to thrive. Of the pathomechanisms of MDC1A, the earliest and most prominent is widespread and rampant fibrosis. Here, we will discuss some of the key drivers of fibrosis including TGF-beta and renin-angiotensin system signaling and consequences of these pathways including myofibroblast transdifferentiation and matrix remodeling. We will also highlight some of the differences in fibrogenesis in congenital muscular dystrophy (CMD) with that seen in Duchenne muscular dystrophy (DMD). Finally, we will connect the key signaling pathways in the pathogenesis of MDC1A to the current status of the therapeutic approaches that have been tested in the preclinical models of MDC1A to treat fibrosis.

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“…It was reported several years ago that transgenic expression of the laminin α1 subunit in dy 3K /dy 3K mice substantially rescued both the muscle and peripheral nerve phenotypes (Gawlik et al, 2004(Gawlik et al, , 2006. Furthermore, in a recent study, it was shown that activation of expression of the α1 subunit by CRISPR-dCas9-mediated upregulation of Lama1 improved the dystrophic phenotype of the dy 2J /dy 2J mouse (Kemaladewi et al, 2019). This represents a new approach to the treatment of LAMA2-MD.…”

Section: Linker Proteins and Repair Of Dystrophic Basement Membranesmentioning

confidence: 83%

Linker Protein Repair of LAMA2 Dystrophic Neuromuscular Basement Membranes

Yurchenco

McKee

2019

Front. Mol. Neurosci.

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An understanding of basement membrane (BM) assembly at a molecular level provides a foundation with which to develop repair strategies for diseases with defects of BM structure. As currently understood, laminins become anchored to cell surfaces through receptor-mediated interactions and polymerize. This provisional matrix binds to proteoglycans, nidogens and type IV collagen to form a mature BM. Identification of BM binding domains and their binding targets has enabled investigators to engineer proteins that link BM components to modify and improve their functions. This approach is illustrated by the development of two linker proteins to repair the LAMA2-deficient muscular dystrophy (LAMA2-MD). Dystrophy-causing mutations of the LAMA2 gene product (Lmα2) disrupt the BM molecular architecture, destabilizing it. In a mild ambulatory type of the dystrophy, α2LN mutations in laminin-211 prevents polymerization. In the more common and severe non-ambulatory type (MDC1A), an absent Lmα2 subunit is replaced by the naturally occurring Lmα4 subunit that is normally largely confined to the microvasculature. The compensatory laminin, however, is a poor substitute because it neither polymerizes nor binds adequately to the anchoring receptor α-dystroglycan. A chimeric laminin-binding protein called αLNNd enables laminins with defective or absent αLN domains to polymerize while another engineered protein, miniagrin (mag), promotes efficient α-dystroglycan receptor-binding in otherwise weakly adhesive laminins. Alone, αLNNd enables Lm211 with a self-assembly defect to polymerize and was used to ameliorate a mouse model of the ambulatory dystrophy. Together, these linker proteins alter Lm411 such that it both polymerizes and binds αDG such that it properly assembles. This combination was used to ameliorate a mouse model of the non-ambulatory dystrophy in which Lm411 replaced Lm211 as seen in the human disease. Collectively, these studies pave the way for the development of somatic gene delivery of repair proteins for treatment of LAMA2-MD. The studies further suggest a more general approach of linker-protein mediated repair in which a variety of existing BM protein domains can be combined together to stabilize BMs in other diseases.

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A mutation-independent approach for muscular dystrophy via upregulation of a modifier gene

Cited by 107 publications

References 37 publications

Synergistic Upregulation of Target Genes by TET1 and VP64 in the dCas9–SunTag Platform

Synergistic Upregulation of Target Genes by TET1 and VP64 in the dCas9–SunTag Platform

Fibrogenesis in LAMA2-Related Muscular Dystrophy Is a Central Tenet of Disease Etiology

Linker Protein Repair of LAMA2 Dystrophic Neuromuscular Basement Membranes

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