metachromatic leukodystrophy
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2022 ◽  
Vol 71 (6) ◽  
pp. 2247-48
Author(s):  
Muhammad Mohsin Sajjad ◽  
Sidra Yousaf

Metachromatic Leukodystrophy is a lysosomal storage autosomal recessive disease characterized by arylsulphatase enzyme deficiency, with central and peripheral demyelination. We report a case of a 15-year-old girl with 6 months history of progressive muscular weakness, poor school performance, gradual memory loss and gait disturbance. Neurological examination was grossly normal, except mild muscle wastage in both upper and lower limbs and slight reduction of power globally in all limbs. Routine bloods including a lumbar puncture was normal and the diagnosis of metachromatic leukodystrophy was made on the findings of magnetic resonance imaging (MRI) brain.


2021 ◽  
Author(s):  
Nayibe Tatiana Sanchez Alvarez ◽  
Paula Katherine Bautista-Niño ◽  
Juanita Trejos-Suárez ◽  
Norma Cecilia Serrano-Díaz

Abstract Background: Metachromatic leukodystrophy (MLD) is a neurological lysosomal deposit disease that has an impact on public health despite its low incidence in the population. Existing treatments are expensive and inefficient. Few reports in the literature on pathophysiological events related to enzyme deficiency and subsequent accumulation of sulfatides; therefore, the use of metformin as an alternative treatment was evaluated in vitro to counteract the effects. Methodology: An experimental in vitro study that sought to determine the effect of the use of metformin on the accumulation of sulfates in glycolysis and mitochondrial function in an in vitro model of metachromatic leukodystrophy. Human Schwann cells (CSH) transfected with CRISPR Cas9 and without transfection were treated with different concentrations of sulfatides and metformin. Cell viability was evaluated by MTT and SYTOX Green; mitochondrial and glycolytic function by Seahorse XFe24, determination of reactive oxygen species (ROS) and cell death. Results: In the MTT trials, we found that treatment with different concentrations of sulfates did not affect cell viability. Transfected CSH showed higher cell death and ROS production when exposed to 100 µM sulfatides with a statistically significant difference (p <0.001), compared to nontransfected CSH cells. Sulfatides at concentrations of 10 to 100 µM affect mitochondrial bioenergetics as concentrations increase in transfected cells, in nontransfected cells they respond metabolically to exposure; Furthermore, transfected cells show a decrease in basal respiration and maximum respiration after being exposed to a concentration of 100 µM of sulphates; however, in double treatment of these cells with both sulfates and Metformin, respiration also decreases. Maximum and normal mitochondrial respiratory capacity. Conclusion: This research describes for the first time the generation of transfected CSH and the bioenergetic and mitochondrial effect of sulfates in Schwann cells, treatment with 500 µM of Metformin restores metabolic activity of these cells and decreases ROS production, as well as prevention of cell death.


2021 ◽  
Author(s):  
Justin S. Antony ◽  
Alberto Daniel-Moreno ◽  
Andrés Lamsfus-Calle ◽  
Janani Raju ◽  
Merve Kaftancioglu ◽  
...  

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3979-3979
Author(s):  
Lucas Tricoli ◽  
Adeline Vanderver ◽  
Laura Adang ◽  
Maxwell Chappell ◽  
Laura Breda ◽  
...  

Abstract Metachromatic Leukodystrophy (MLD) is an autosomal recessive lysosomal storage disease (LSD) characterized by a decreased Arylsulfatatse A (ARSA) enzymatic activity. The most common form, late infantile MLD, universally results in rapid loss of neurologic function in early childhood. Ex-vivo hematopoietic stem cell (HSC) gene therapy using a lentiviral vector (LV) can improve clinical outcomes by supplying a functional copy of the ARSA cDNA (Biffi A, et al, Science 2013). Unfortunately, this approach is only successful in pre- and minimally symptomatic individuals and only a small subset of individuals are diagnosed during the limited therapeutic window. As such, the development of additional approaches targeting early symptomatic individuals are critically needed. The only clinical vector (CV) approved to treat MLD patients, PawMut6, includes the human ARSA cDNA gene under the control of the human Phosphoglycerate Kinase (PGK) promoter and includes, in the integrating transcriptional unit, the viral sequences Woodchuck Hepatitis Virus Posttranscriptional Regulatory Element (WPRE) sequence to increase titer and mRNA translation (Biffi A, et al, Science 2013). To increase expression of ARSA cDNA at single integration level, we generated several LVs that include the ARSA gene with a variety of insulators to optimize ARSA expression and enhance safety in transduced cell lines. We placed the ARSA cDNA under the control of the human Elongation Factor 1 alpha (EF1-alpha) promoter, which has been shown to promote higher transcription rates in different cell lines, compared to human PGK as shown by Jane Yuxia Qin, PLos One 2010. Our constructs carry versions of the ARSA gene with and without the 5' and 3' untranslated regions (UTR+ or UTR-) and a Traceable Codon Optimized (TCO) modified sequence to distinguish the transgene from the endogenous ARSA. An ankyrin or foamy insulator have been incorporated to minimize genotoxicity caused by integration events. The WPRE has been proven to enhance the performance of viral vectors. However, to prevent WPRE integration in the host genome, we placed it directly after the 3'-self inactivating LTR (SIN-LTR) together with a strong bovine growth hormone polyA signal (for sequence termination) (BGHpA), as shown by Breda L. et al, Mol Ther 2021. We compared the ARSA activity (normalized to vector copy number (VCN)) of our constructs to that of PawMut6, the LV currently used in clinical trial, on MLD primary patient fibroblast cultures. Our top performing vectors, TCO-EAAWP-UTR +, TCO-EAFWP-UTR - and TCO-AEAFWP-UTR - showed 2X, 10X and 4X more ARSA activity, respectively, compared to that generated using PawMut6. We also detected a superior ability of our vectors to secrete functional ARSA enzyme into the culture media of transduced primary MLD patient fibroblast cells, which is a critical modality for transfer of functional ARSA from microglia to oligodendrocytes. Extracellular vesicle isolation, purification, and immunoblot analysis has demonstrated small vesicle secretion is the primary modality by which ARSA is secreted, having significant implication for how we approach treatment of MLD. In parallel experiments on murine HSC, the TCO-AEAFWP-UTR - vector reproduced similar results, with about 4x more ARSA activity. To exclude potential toxicity, we performed bone marrow transplants on WT animals with HSCs transduced at up to 13 copies per genome. Mice transplanted with high VCN transduced bone marrow did not show signs of bone marrow failure or distress; more extensive evaluation of these animal models is ongoing. Clonogenic assays and secondary transplants are in progress. Upon completion of the in-vivo studies in WT mice, at least two of our best vector candidates will be utilized on a MLD mouse model (ARSA-KO) that we generated using CRISPR-Cas9. Analysis will include pathological sections of the CNS, brain lysate collection and sulfatase activity assays. Our studies are currently focused on completing in-vivo validation and toxicity assays to move our best vector to the pre-clinical and IND application. The accumulated data on our novel vectors imply new mechanistic considerations for treatment of MLD and demonstrate utility as a strong approach for treating early symptomatic patients. Disclosures Vanderver: Homology: Research Funding; Takeda: Research Funding; Ionis and Illumina Inc: Research Funding; Biogen: Research Funding; Eli Lily and Company: Research Funding; Orchard Therapeutics: Research Funding; Gilead Sciences Inc: Research Funding. Adang: MEGMA: Consultancy; Orchard Therapeutics: Consultancy; Takeda Pharmaceuticals: Consultancy. Rivella: Keros Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Disc Medicine: Consultancy, Membership on an entity's Board of Directors or advisory committees; Ionis Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Incyte: Consultancy; Forma Theraputics: Consultancy; MeiraGTx: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene Corporation: Consultancy.


JPGN Reports ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. e122
Author(s):  
James P. Stevens ◽  
Janani Dakshinamoorthy ◽  
Anne Elizabeth Gill ◽  
Paul Parker ◽  
Duke Geem ◽  
...  

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