Activated dendritic cells modulate proliferation and differentiation of human myoblasts

International audienceIdiopathic Inflammatory Myopathies (IIMs) are a heterogeneous group of autoimmune diseases affecting skeletal muscle tissue homeostasis. They are characterized by muscle weakness and inflammatory infiltration with tissue damage. Amongst the cells in the muscle inflammatory infiltration, dendritic cells (DCs) are potent antigen-presenting and key components in autoimmunity exhibiting an increased activation in inflamed tissues. Since, the IIMs are characterized by the focal necrosis/regeneration and muscle atrophy, we hypothesized that DCs may play a role in these processes. Due to the absence of a reliable in vivo model for IIMs, we first performed co-culture experiments with immature DCs (iDC) or LPS-activated DCs (actDC) and proliferating myoblasts or differentiating myotubes. We demonstrated that both iDC or actDCs tightly interact with myoblasts and myotubes, increased myoblast proliferation and migration, but inhibited myotube differentiation. We also observed that actDCs increased HLA-ABC, HLA-DR, VLA-5, and VLA-6 expression and induced cytokine secretion on myoblasts. In an in vivo regeneration model, the co-injection of human myoblasts and DCs enhanced human myoblast migration, whereas the absolute number of human myofibres was unchanged. In conclusion, we suggest that in the early stages of myositis, DCs may play a crucial role in inducing muscle-damage through cell-cell contact and inflammatory cytokine secretion, leading to muscle regeneration impairment

CONTROL OF SEDIMENT DISCHARGE BY SABO DAM

Sabo dam is commonly used for preventing the sediment disaster by storing the harmfulsediment discharge. Even after the sediment storage capacity of the dam has been filledup, the dam has a sediment control function by reducing the peak sediment discharge dueto the temporal sedimentation during flood. The sediment capacity can be restored to someextent by the erosion after flood.In this paper, the authors investigated the sediment control function experimentally andtheoretically, and proposed a simulation technique to calculate the sediment control. Thetheoretical results show the good agreement with the experimental ones. By the simulationtechnique, the authors clarified that the contraction in width by dam results in much increaseof the sediment control function.Sabo dam is commonly used for preventing the sediment disaster by storing the harmfulsediment discharge. Even after the sediment storage capacity of the dam has been filledup, the dam has a sediment control function by reducing the peak sediment discharge dueto the temporal sedimentation during flood. The sediment capacity can be restored to someextent by the erosion after flood.In this paper, the authors investigated the sediment control function experimentally andtheoretically, and proposed a simulation technique to calculate the sediment control. Thetheoretical results show the good agreement with the experimental ones. By the simulationtechnique, the authors clarified that the contraction in width by dam results in much increaseof the sediment control function

Additional file 1: Figure S1. of Nanospan, an alternatively spliced isoform of sarcospan, localizes to the sarcoplasmic reticulum in skeletal muscle and is absent in limb girdle muscular dystrophy 2F

nSPN mRNA transcripts are predominant in skeletal and heart muscles. RT-PCR was performed on cDNA isolated from various human tissues (skeletal muscle, testis, colon, heart, brain, breast, and bone marrow) using a forward primer in exon 1 and a reverse primer in exon 4, as illustrated in Fig. 1c. PCR products were obtained for μSPN (179 bp) and nSPN (90 bp). RT-PCR performed without template DNA is shown as a negative control (neg. ctrl). Molecular size markers are indicated on the left. (PDF 348 kb

Activated dendritic cells modulate proliferation and differentiation of human myoblasts

Submitted by Sandra Infurna ([email protected]) on 2018-08-30T11:27:17Z No. of bitstreams: 1 ingo_riederer_etal_IOC_2018.pdf: 4869218 bytes, checksum: 5c2cc86e5c212e47523493aa9299d736 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2018-08-30T11:40:38Z (GMT) No. of bitstreams: 1 ingo_riederer_etal_IOC_2018.pdf: 4869218 bytes, checksum: 5c2cc86e5c212e47523493aa9299d736 (MD5)Made available in DSpace on 2018-08-30T11:40:38Z (GMT). No. of bitstreams: 1 ingo_riederer_etal_IOC_2018.pdf: 4869218 bytes, checksum: 5c2cc86e5c212e47523493aa9299d736 (MD5) Previous issue date: 2018Universidade Federal do Rio de Janeiro. Instituto de Biofísica Carlos Chagas Filho. Rio de Janeiro, RJ, Brasil / Sorbonne Université. Institut fr Myologie. Paris, France.Sorbonne Université. Institut de Myologie. Paris, France.Sorbonne Université. Immunology-Immunopathology-Immunotherapy. Paris, France.Sorbonne Université. Institut de Myologie. Paris, France.Sorbonne Université. Institut de Myologie. Paris, France.Sorbonne Université. Institut de Myologie. Paris, France.Sorbonne Université. Immunology-Immunopathology-Immunotherapy. Paris, France.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Pesquisa sobre o Timo. Rio de Janeiro, RJ. Brasil.Sorbonne Université. Institut de Myologie. Paris, France.Sorbonne Université. Institut de Myologie. Paris, France.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Pesquisa sobre o Timo. Rio de Janeiro, RJ. Brasil / Instituto Nacional de Ciência e Tecnologia em Neuroimunomodulação. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Pesquisa sobre o Timo. Rio de Janeiro, RJ. Brasil / Instituto Nacional de Ciência e Tecnologia em Neuroimunomodulação. Rio de Janeiro, RJ, Brasil.Sorbonne Université. Institut de Myologie. Paris, France.Sorbonne Université. Institut de Myologie. Paris, France.Universidade Federal do Rio de Janeiro. Instituto de Biofísica Carlos Chagas Filho. Rio de Janeiro, RJ, Brasil.Idiopathic Inflammatory Myopathies (IIMs) are a heterogeneous group of autoimmune diseases affecting skeletal muscle tissue homeostasis. They are characterized by muscle weakness and inflammatory infiltration with tissue damage. Amongst the cells in the muscle inflammatory infiltration, dendritic cells (DCs) are potent antigen-presenting and key components in autoimmunity exhibiting an increased activation in inflamed tissues. Since, the IIMs are characterized by the focal necrosis/regeneration and muscle atrophy, we hypothesized that DCs may play a role in these processes. Due to the absence of a reliable in vivo model for IIMs, we first performed co-culture experiments with immature DCs (iDC) or LPS-activated DCs (actDC) and proliferating myoblasts or differentiating myotubes. We demonstrated that both iDC or actDCs tightly interact with myoblasts and myotubes, increased myoblast proliferation and migration, but inhibited myotube differentiation. We also observed that actDCs increased HLA-ABC, HLA-DR, VLA-5, and VLA-6 expression and induced cytokine secretion on myoblasts. In an in vivo regeneration model, the co-injection of human myoblasts and DCs enhanced human myoblast migration, whereas the absolute number of human myofibres was unchanged. In conclusion, we suggest that in the early stages of myositis, DCs may play a crucial role in inducing muscle-damage through cell-cell contact and inflammatory cytokine secretion, leading to muscle regeneration impairment