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1.
Insects ; 13(3)2022 Mar 15.
Article in English | MEDLINE | ID: mdl-35323586

ABSTRACT

In Morocco, there are two well-recognised honey bee (Apis mellifera L.) subspecies: A. m. intermissa in the north and A. m. sahariensis in the south-east. The latter subspecies is found in the arid and semiarid climates of the Sahara Desert. In this study, we used honey bees from four areas of south-eastern Morocco which are, to some degree, isolated by arid zones. We analysed the shape and size of the forewings, using the method of geometric morphometrics. The bees from the four areas of south-eastern Morocco differed significantly in terms of wing shape. Moreover, bees from traditional hives were smaller than those from modern hives. The bees from south-eastern Morocco were clearly different from the reference samples obtained from the Morphometric Bee Data Bank in Oberursel, Germany, representing most of the global variation in honey bees. Surprisingly, the bees were also different from A. m. sahariensis, which should occur in the study area, according to earlier studies. This difference could have been caused by introgression with non-native subspecies imported by beekeepers. The distinct honey bees from south-eastern Morocco deserve to be protected. We provide a method for identifying them, which can help protect them.

2.
Mol Ther ; 21(10): 1950-7, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23975040

ABSTRACT

The development of innovative therapeutic strategies for muscular dystrophies, particularly cell-based approaches, is still a developing field. Although positive results have been obtained in animal models, they have rarely been confirmed in patients and resulted in very limited clinical improvements, suggesting some specificity in humans. These findings emphasized the need for an appropriate animal model (i.e., immunodeficient and dystrophic) to investigate in vivo the behavior of transplanted human myogenic stem cells. We report a new model, the Rag2(-)Il2rb(-)Dmd(-) mouse, which lacks T, B, and NK cells, and also carries a mutant Dmd allele that prevents the production of any dystrophin isoform. The dystrophic features of this new model are comparable with those of the classically used mdx mouse, but with the total absence of any revertant dystrophin positive fiber. We show that Rag2(-)Il2rb(-)Dmd(-) mice allow long-term xenografts of human myogenic cells. Altogether, our findings indicate that the Rag2(-)Il2rb(-)Dmd(-) mouse represents an ideal model to gain further insights into the behavior of human myogenic stem cells in a dystrophic context, and can be used to assess innovative therapeutic strategies for muscular dystrophies.


Subject(s)
DNA-Binding Proteins/genetics , Disease Models, Animal , Dystrophin/genetics , Interleukin-2 Receptor beta Subunit/genetics , Mice, Inbred mdx/genetics , Muscular Dystrophies/pathology , Muscular Dystrophy, Animal/pathology , Animals , Cell- and Tissue-Based Therapy/methods , Gene Knockout Techniques , Humans , Infant, Newborn , Male , Mice , Mice, Inbred C57BL , Muscular Dystrophies/therapy , Muscular Dystrophy, Animal/therapy , Myoblasts/transplantation , Transplantation, Heterologous , Xenograft Model Antitumor Assays
3.
Mol Ther ; 20(11): 2168-79, 2012 Nov.
Article in English | MEDLINE | ID: mdl-23070116

ABSTRACT

Macrophages have been shown to be essential for muscle repair by delivering trophic cues to growing skeletal muscle precursors and young fibers. Here, we investigated whether human macrophages, either proinflammatory or anti-inflammatory, coinjected with human myoblasts into regenerating muscle of Rag2(-/-) γC(-/-) immunodeficient mice, could modify in vivo the kinetics of proliferation and differentiation of the transplanted human myogenic precursors. Our results clearly show that proinflammatory macrophages improve in vivo the participation of injected myoblasts to host muscle regeneration, extending the window of proliferation, increasing migration, and delaying differentiation. Interestingly, immunostaining of transplanted proinflammatory macrophages at different time points strongly suggests that these cells are able to switch to an anti-inflammatory phenotype in vivo, which then may stimulate differentiation during muscle regeneration. Conceptually, our data provide for the first time in vivo evidence strongly suggesting that proinflammatory macrophages play a supportive role in the regulation of myoblast behavior after transplantation into preinjured muscle, and could thus potentially optimize transplantation of myogenic progenitors in the context of cell therapy.


Subject(s)
Cell Differentiation , Cell Proliferation , Macrophages/physiology , Muscle, Skeletal/physiopathology , Myoblasts, Skeletal/physiology , Animals , Cell Survival , Cells, Cultured , DNA-Binding Proteins/genetics , Dystrophin/metabolism , Humans , Kinetics , Lamin Type A/metabolism , Macrophages/immunology , Macrophages/transplantation , Mice , Mice, Knockout , Muscle, Skeletal/immunology , Muscular Dystrophy, Duchenne/immunology , Muscular Dystrophy, Duchenne/metabolism , Muscular Dystrophy, Duchenne/therapy , Myoblasts, Skeletal/transplantation , Regeneration , Regenerative Medicine , Spectrin/metabolism
4.
Mol Ther ; 20(1): 146-54, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21934656

ABSTRACT

We have used a model of xenotransplantation in which human myoblasts were transplanted intramuscularly into immunodeficient Rag2(-/-)γC(-/-) mice, in order to investigate the kinetics of proliferation and differentiation of the transplanted cells. After injection, most of the human myoblasts had already differentiated by day 5. This differentiation correlated with reduction in proliferation and limited migration of the donor cells within the regenerating muscle. These results suggest that the precocious differentiation, already detected at 3 days postinjection, is a limiting factor for both the migration from the injection site and the participation of the donor cells to muscle regeneration. When we stimulated in vivo proliferation of human myoblasts, transplanting them in a serum-containing medium, we observed 5 days post-transplantation a delay of myogenic differentiation and an increase in cell numbers, which colonized a much larger area within the recipient's muscle. Importantly, these myoblasts maintained their ability to differentiate, since we found higher numbers of myofibers seen 1 month postengraftment, as compared to controls. Conceptually, these data suggest that in experimental myoblast transplantation, any intervention upon the donor cells and/or the recipient's microenvironment aimed at enhancing proliferation and migration should be done before differentiation of the implanted cells, e.g., day 3 postengraftment.


Subject(s)
Cell Differentiation , Cell Movement/physiology , Myoblasts/cytology , Myoblasts/transplantation , Animals , Cell Cycle Checkpoints , Cell Proliferation , Humans , Infant, Newborn , Mice , Mice, Knockout , Mice, SCID , Muscle, Skeletal/physiology , Primary Cell Culture , Regeneration/physiology , Transplantation, Heterologous
5.
Skelet Muscle ; 1: 34, 2011 Nov 01.
Article in English | MEDLINE | ID: mdl-22040608

ABSTRACT

BACKGROUND: Investigations into both the pathophysiology and therapeutic targets in muscle dystrophies have been hampered by the limited proliferative capacity of human myoblasts. Isolation of reliable and stable immortalized cell lines from patient biopsies is a powerful tool for investigating pathological mechanisms, including those associated with muscle aging, and for developing innovative gene-based, cell-based or pharmacological biotherapies. METHODS: Using transduction with both telomerase-expressing and cyclin-dependent kinase 4-expressing vectors, we were able to generate a battery of immortalized human muscle stem-cell lines from patients with various neuromuscular disorders. RESULTS: The immortalized human cell lines from patients with Duchenne muscular dystrophy, facioscapulohumeral muscular dystrophy, oculopharyngeal muscular dystrophy, congenital muscular dystrophy, and limb-girdle muscular dystrophy type 2B had greatly increased proliferative capacity, and maintained their potential to differentiate both in vitro and in vivo after transplantation into regenerating muscle of immunodeficient mice. CONCLUSIONS: Dystrophic cellular models are required as a supplement to animal models to assess cellular mechanisms, such as signaling defects, or to perform high-throughput screening for therapeutic molecules. These investigations have been conducted for many years on cells derived from animals, and would greatly benefit from having human cell models with prolonged proliferative capacity. Furthermore, the possibility to assess in vivo the regenerative capacity of these cells extends their potential use. The innovative cellular tools derived from several different neuromuscular diseases as described in this report will allow investigation of the pathophysiology of these disorders and assessment of new therapeutic strategies.

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