Recent scientific articles relevant to Sanfilippo Syndrome: May 4, 2022, digest

May 4, 2022

Every week thousands of scientific articles on various topics are published. Here are some recent articles and abstracts that are relevant to understanding, managing, and/or treating Sanfilippo Syndrome (mucopolysaccharidosis III or MPS III).

“Caregivers’ assessment of meaningful and relevant clinical outcome assessments for Sanflippo syndrome”

Published: Journal of Patient-Reported Outcomes, April 25, 2022

Authors: Katherine Ackerman Porter, Cara O’Neill, Elise Drake, Sara M. Andrews, Kathleen Delaney, Samantha Parker, Maria L. Escolar, Stacey Montgomery, William Moon, Carolyn Worrall, and Holly L. Peay.

Objectives:Sanfilippo syndrome is a rare multisystem disease with no approved treatments. This study explores caregiver perspectives on the most impactful symptoms and patient-relevant clinical outcomes assessments. The pediatric onset and progressive neurodegenerative nature of Sanfilippo limits use of self-report in clinical research. This study obtains Sanfilippo caregiver data to support the selection of fit-for-purpose and patient-relevant clinical outcome assessments (COAs).”

Results: “Participants’ children were 2–24 years in age and varied in disease progression. Caregivers reported communication and mobility as highly impactful domains with unmet treatment needs, followed closely by pain and sleep. Domains such as eating, adaptive skills, and behaviors were identified as impactful but with relatively less priority, by comparison. Participants endorsed the relevance of clinical outcome assessments associated with communication, eating, sleep, and pain, and identified them as highly favorable for use in a clinical trial. Participants specified some refinements in existing assessments to best reflect Sanfilippo symptoms and disease course.”

Read more: Read the entire article

“Fluoxetine ameliorates mucopolysaccharidosis type IIIA”

Published: Molecular Therapy, April 6, 2022

Authors: Antonella Capuozzo, Sandro Montefusco, Vincenzo Cacace, Martina Sofia, Alessandra Esposito, Gennaro Napolitano, Eduardo Nusco, Elena Polishchuk, Maria Teresa Pizzo, Maria De Risi, Elvira De Leonibus, Nicolina Cristina Sorrentino, Diego Luis Medina.

Abstract: Mucopolysaccharidosis type IIIA (MPS-IIIA) is an autosomal recessive disorder caused by mutations in SGSH involved in the degradation of heparan sulfate. MPS-IIIA presents severe neurological symptoms such as progressive developmental delay and cognitive decline, for which there is currently no treatment. Brain targeting represents the main challenge for therapeutics to treat MPS-IIIA, and the development of small-molecule-based treatments able to reach the CNS could be a relevant advance for therapy. Using cell-based high content imaging to survey clinically approved drugs in MPS-IIIA cells, we identified fluoxetine, a selective serotonin reuptake inhibitor. Fluoxetine increases lysosomal and autophagic functions via TFEB activation through a RagC-dependent mechanism. Mechanistically, fluoxetine increases lysosomal exocytosis in mouse embryonic fibroblasts from MPS-IIIA mice, suggesting that this process may be responsible for heparan sulfate clearance. In vivo, fluoxetine ameliorates somatic and brain pathology in a mouse model of MPS-IIIA by decreasing the accumulation of glycosaminoglycans and aggregated autophagic substrates, reducing inflammation, and slowing down cognitive deterioration. We repurposed fluoxetine for potential therapeutics to treat human MPS-IIIA disease.”

Read more: Read the abstract*

*Note: To read the entire article, access to Molecular Therapy is required. 

“Complex Changes in the Efficiency of the Expression of Many Genes in Monogenic Diseases, Mucopolysaccharidoses, May Arise from Significant Disturbances in the Levels of Factors Involved in the Gene Expression Regulation Process”

Published: Genes, March 26, 2022

Authors: Zuzanna Cyske, Lidia Gaffke, Karolina Pierzynowska, Gregorz Wegrzyn.

Abstract:Monogenic diseases are primarily caused by mutations in a single gene; thus, they are commonly recognized as genetic disorders with the simplest mechanisms. However, recent studies have indicated that the molecular mechanisms of monogenic diseases can be unexpectedly complicated, and their understanding requires complex studies at the molecular level. Previously, we have demonstrated that in mucopolysaccharidoses (MPS), a group of monogenic lysosomal storage diseases, several hundreds of genes reveal significant changes in the expression of various genes. Although the secondary effects of the primary biochemical defect and the inefficient degradation of glycosaminoglycans (GAGs) might be considered, the scale of the changes in the expression of a large fraction of genes cannot be explained by a block in one biochemical pathway. Here, we demonstrate that in cellular models of 11 types of MPS, the expression of genes coding for proteins involved in the regulation of the expression of many other genes at various stages (such as signal transduction, transcription, splicing, RNA degradation, translation, and others) is significantly disturbed relative to the control cells. This conclusion was based on transcriptomic studies, supported by biochemical analyses of levels of selected proteins encoded by genes revealing an especially high level of dysregulation in MPS (EXOSC9, SRSF10, RPL23, and NOTCH3 proteins were investigated). Interestingly, the reduction in GAGs levels, through the inhibition of their synthesis normalized the amounts of EXOSC9, RPL23, and NOTCH3 in some (but not all) MPS types, while the levels of SRSF10 could not be corrected in this way. These results indicate that different mechanisms are involved in the dysregulation of the expression of various genes in MPS, pointing to a potential explanation for the inability of some therapies (such as enzyme replacement therapy or substrate reduction therapy) to fully correct the physiology of MPS patients. We suggest that the disturbed expression of some genes, which appears as secondary or tertiary effects of GAG storage, might not be reversible, even after a reduction in the amounts of the storage material.

Read more: Read the entire article

“Understanding disease symptoms and impacts and producing qualitatively-derived severity stages for MPS IIIA: a mixed methods approach”

Published: Orphanet Journal of Rare Diseases, February 22, 2022

Authors: Sally Lanar, Samantha Parker, Cara O’Neill, Alexia Marrel, Benoit Arnould, Bénédicte Héron, Nicole Muschol, Frits A. Wijburg, Anupam Chakrapani, Sophie Olivier & Karen Aiach

Abstract:Assays that measure lysosomal enzyme activity are important tools for the screening and diagnosis of lysosomal storage disorders (LSDs). They are often ordered in combination with urine oligosaccharide and glycosaminoglycan analysis, additional biomarker assays, and/or DNA sequencing when an LSD is suspected. Enzyme testing in whole blood/leukocytes, serum/plasma, cultured fibroblasts, or dried blood spots demonstrating deficient enzyme activity remains a key component of LSD diagnosis and is often prompted by characteristic clinical findings, abnormal newborn screening, abnormal biochemical findings (eg, elevated glycosaminoglycans), or molecular results indicating pathogenic variants or variants of uncertain significance in a gene associated with an LSD. This document, which focuses on clinical enzyme testing for LSDs, provides a resource for laboratories to develop and implement clinical testing, to describe variables that can influence test performance and interpretation of results, and to delineate situations for which follow-up molecular testing is warranted.

Read more: Read the entire article

“Measurement of lysosomal enzyme activities: A technical standard of the American College of Medical Genetics and Genomics (ACMG)”

Published: Genetics in Medicine, February 10, 2022

Authors: Erin T. Strovel, Kristina Cusmano-Ozog, Tim Wood, Chunli Yu

Abstract:Assays that measure lysosomal enzyme activity are important tools for the screening and diagnosis of lysosomal storage disorders (LSDs). They are often ordered in combination with urine oligosaccharide and glycosaminoglycan analysis, additional biomarker assays, and/or DNA sequencing when an LSD is suspected. Enzyme testing in whole blood/leukocytes, serum/plasma, cultured fibroblasts, or dried blood spots demonstrating deficient enzyme activity remains a key component of LSD diagnosis and is often prompted by characteristic clinical findings, abnormal newborn screening, abnormal biochemical findings (eg, elevated glycosaminoglycans), or molecular results indicating pathogenic variants or variants of uncertain significance in a gene associated with an LSD. This document, which focuses on clinical enzyme testing for LSDs, provides a resource for laboratories to develop and implement clinical testing, to describe variables that can influence test performance and interpretation of results, and to delineate situations for which follow-up molecular testing is warranted.

Read more: Read the entire article

Source: All information is sourced directly from the scientific abstracts and articles published by the researchers.

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