Trafficking of Annexins during Membrane Repair in Human Skeletal Muscle Cells

Abstract

Defects in membrane repair contribute to the development of muscular dystrophies, such as Miyoshi muscular dystrophy 1, limb girdle muscular dystrophy (LGMD), type R2 or R12. Deciphering membrane repair dysfunctions in the development of muscular dystrophies requires precise and detailed knowledge of the membrane repair machinery in healthy human skeletal muscle cells. Using correlative light and electron microscopy (CLEM), we studied the trafficking of four members of the annexin (ANX) family, in myotubes damaged by laser ablation. Our data support a model in which ANXA4 and ANXA6 are recruited to the disruption site by propagating as a wave-like motion along the sarcolemma. They may act in membrane resealing by proceeding to sarcolemma remodeling. On the other hand, ANXA1 and A2 exhibit a progressive cytoplasmic recruitment, likely by interacting with intracellular vesicles, in order to form the lipid patch required for membrane resealing. Once the sarcolemma has been resealed, ANXA1 is released from the site of the membrane injury and returns to the cytosol, while ANXA2 remains accumulated close to the wounding site on the cytoplasmic side. On the other side of the repaired sarcolemma are ANXA4 and ANXA6 that face the extracellular milieu, where they are concentrated in a dense structure, the cap subdomain. The proposed model provides a basis for the identification of cellular dysregulations in the membrane repair of dystrophic human muscle cells.

Annexin‐A5 and annexin‐A6 silencing prevents metastasis of breast cancer cells in zebrafish

“…In contrast, laser‐damaged sgANXA5, sgANXA6, or sgANXA5/A6 MDA‐MB‐231 cells exhibited systematically a strong and large increase of the intracellular fluorescence intensity (Figures 4b,c and S6), which indicated that they were unable to reseal cell membrane damage. To complete this set of experiments, we then analyzed the traffic of ANXA5 and ANXA6 in membrane‐damaged MDA‐MB‐231 cells, since most key membrane repair proteins have been reported of being rapidly recruited to the disruption site (Croissant et al., 2021; Croissant et al., 2022). In MDA‐MB‐231 cells transfected with either ANXA5‐GFP or ANXA6‐GFP vector, cell membrane was damaged by laser ablation and the subcellular trafficking of each annexin was analyzed.…”

“…For the subcellular trafficking analysis of ANXA5‐GFP or ANXA6‐GFP, MDA‐MB‐231 cells cultured in 35‐mm glass bottom dishes (MatTek, Ashland, USA) were transfected by the pA5‐GFP or pA6‐GFP plasmid (Croissant et al., 2022). Membrane damage was performed by laser ablation as described above, without FM1‐43.…”

Application of Mesoporous Silica Nanoparticle-Chitosan-Loaded BMP-2 in the Repair of Bone Defect in Chronic Osteomyelitis

“…Thanks to the porous structure, MSN is able to provide cavities that can accommodate and release biomolecules and therapeutic agents of large quantities [ 37 ]. In fact, it is the versatility of MSN in size, morphology, and texture that has driven its application as a nanocarrier for controlled drug delivery [ 38 ]. Otherwise, “NH2” of chitosan can form hydrogen bond with BMP-2 to realize noncovalent fixation [ 39 ].…”

Role of calcium-sensor proteins in cell membrane repair

“…The S100A10:ANX2 complex also localizes at membrane injury sites [ 156 ]. Both ANX1 and ANX2 translocate to the membrane in damaged human and zebrafish muscle cells, although at different rates that may depend on localization prior to a rupture [ 199 , 200 ]. Annexin knockout experiments display poor myofiber repair or muscle regeneration abilities [ 201–203 ].…”