MIGLIOR ARTICOLO DEL MESE CON PRIMO AUTORE ITALIANO

Muscle magnetic resonance imaging in myotonic dystrophy type 1 (MD1): Refining muscle involvement and implications for clinical trials

Matteo Garibaldi, Tommaso Nicoletti, Elisabetta Bucci, Laura Fionda, Luca Leonardi, Stefania Morino, Laura Tufano, Girolamo Alfieri, Antonio Lauletta, Gioia Merlonghi, Alessia Perna, Salvatore Rossi, Enzo Ricci, Jorge Alonso Perez, Tommaso Tartaglione, Antonio Petrucci, Elena Maria Pennisi, Marco Salvetti, Gary Cutter, Jordi Díaz-Manera, Gabriella Silvestri, Giovanni Antonini.

Garibaldi et al. Eur J Neurol. 2022 Mar;29(3):843-854.

Selezionato dal lettore: Dott.ssa Giuseppa Jolanda Rosa

Motivation: Myotonic dystrophy type 1 (DM1), or Steinert’s disease, is a progressive multisystem genetic disorder that affects striated and smooth muscles, eyes, endocrine system, and central nervous system.
This multicenter and retrospective study investigated the MRI muscles involvement and the possible correlation between MRI scores, clinical features, and genetic background in 134 MD1 patients. Authors analyzing lower and upper limbs STIR and T1-weighted sequences defined the pattern of muscle involvement and detected a correlation between MRI (T1-weighted and STIR) hyperintensities and muscle atrophy with disease severity and duration. Moreover, MRI-STIR hyperintensities preceded the T1-weighted ones in some muscles: therefore, an active process might precede fat replacement. This study underlines the role of MRI, mainly of STIR positivity, as a biomarker of disease severity and treatment efficacy (also in the mildest spectrum of disease) and suggests a composite pathophysiological mechanism for muscle wasting and weakness in MD1.

ARTICOLO DEL MESE IN ASSOLUTO

Treatment of a genetic brain disease by CNS-wide microglia replacement

Yohei Shibuya; Kevin K. Kumar; Marius Marc-Daniel Mader; Yongjin Yoo; Luis Angel Ayala; Mu Zhou; Manuel Alexander Mohr; Gernot Neumayer; Ishan Kumar; Ryo Yamamoto; Paul Marcoux; Benjamin Liou; F. Chris Bennett; Hiromitsu Nakauchi; Ying Sun; Xiaoke Chen; Frank L. Heppner; Tony Wyss-Coray; Thomas C. Südhof; Marius Wernig

Science Translational Medicine 2022

Selezionato dal lettore: Dott. Giacomo Sferruzza

Motivation: In the last decay, gene therapy has provided remarkable results in several forms of inherited metabolic disorders, both in a preclinical and clinical setting. A relevant open question regarding this therapeutic approach regards the gene therapy delivery methods. Considering the widespread distribution of hematopoietic cells and their continued turnover, the use of modified hematopoietic stem cells (HSC) transplantation has been used as a feasible therapeutic strategy to solve this problem. However, since microglia, the brain-resident macrophage population, is a long-living and self-regenerating population within the brain, HSC transplantation has provided limited results in diseases involving the central nervous system.
In this pioneering study, the Authors provided a proof-of-concept of rapid and near-complete microglia replacement with circulation-derived myeloid cells (CDCM). By means of a protocol consisting of 4 weeks of treatment with PLX5622, a potent CSF1R inhibitor, after bone marrow transplantation, the Authors displayed a near-complete replacement of microglia with CDMCs throughout the entire brain.
The new Iba1+ resident population remained stably incorporated for at least 6 months after transplantation, even though it displays important differences in terms of gene expression, morphology, cell density and motility compared to the native microglia. Comprehensibly, they emphasized these aspects, underlining that the long-term effects of microglia replacement on the brain and immune functions need to be further investigated.
In the second part of the study, microglia replacement after bone marrow transplantation was investigated as a therapeutic tool in a mouse model of progressive neurodegenerative disease. In particular, a lysosomal enzyme glucocerebrosidase deficit was investigated through different genetic models. The Author showed that CDMCs engineered to efficiently secrete the deficient enzyme were able, after microglia replacement, to reduce CNS pathology even if administrated around the time of disease onset.
This study provides a precious contribution to the field of central nervous system diseases, displaying the feasibility of microglia replacement in the animal model, leading the way to new applications in metabolic and neurodegenerative diseases.