👤 Nooshin Tasharrofi

Mutations in the branched-chain keto-acid dehydrogenase kinase gene (BCKDK), leading to low plasma branched-chain amino acids (BCAAs) levels, have been reported as a contributor to comorbid intellectual disability, autism, epilepsy, and neurodevelopmental delay (NDD). Due to the rarity of knowledge about these mutations, the current case series aims to introduce four confirmed cases. This case series study analyzed children from a neurometabolic clinic. Social and adaptive functions were assessed using the vineland social maturity scale (VSMS). Whole exome sequencing (WES) identified genetic variants filtered using population databases. Candidate variants were confirmed through Sanger sequencing and interpreted based on ACMG guidelines. Four children of unrelated consanguineous families suffering from global NDD and autism were referred to our center. Neuroimaging assessments revealed negligible findings; thus, metabolic tests were sent, in which BCAAs were lower than normal limits. Therefore, genetic testing was done, and genetic variants compatible with BCKDK deficiency were detected. By initiating a BCAAs-rich regimen, the patients had significant improvements in psychomotor and speech development. The diagnosis of BCKDK deficiency should be suspected in patients with NDD and autism, and BCAA supplementation should be initiated as soon as diagnosis confirmation to prevent irreversible brain damage. The results emphasize that early diagnosis and dietary intervention by regulating plasma BCAA levels lead to the prevention of irreversible neurodevelopmental implications. Show less

New insights on cellular and molecular aspects of both oligodendrocyte (OL) differentiation and myelin synthesis pathways are potential avenues for developing a cell-based therapy for demyelinating disorders comprising multiple sclerosis. MicroRNAs (miRNA) have broad implications in all aspects of cell biology including OL differentiation. MiR-184 has been identified as one of the most highly enriched miRNAs in oligodendrocyte progenitor cells (OPCs). However, the exact molecular mechanism of miR-184 in OL differentiation is yet to be elucidated. Based on immunochemistry assays, qRT-PCR, and western blotting findings, we hypothesized that overexpression of miR-184 in either neural progenitor cells (NPCs) or embryonic mouse cortex stimulated the differentiation of OL lineage efficiently through regulating crucial developmental genes. Luciferase assays demonstrated that miR-184 directly represses positive regulators of neural and astrocyte differentiation, i.e., SOX1 and BCL2L1, respectively, including the negative regulator of myelination, LINGO1. Moreover, blocking the function of miR-184 reduced the number of committed cells to an OL lineage. Our data highlighted that miR-184 could promote OL differentiation even in the absence of exogenous growth factors and propose a novel strategy to improve the efficacy of OL differentiation, with potential applications in cell therapy for neurodegenerative diseases. Show less