Plectin is a cytolinker, connecting cytoskeletal elements, and is also involved in the organization of individual organelles. The role of plectin in astrocytes has not yet been investigated. In immortalized and primary mouse astrocytes expressing plectin, and in immortalized and primary mouse astrocytes devoid of plectin gene, along with plasmids encoding various plectin isoforms, and fluorescent confocal microscopy, we assessed the organization of cytoskeletal elements, the migration speed of astrocytes, and the morphology and function of the mitochondrial network. We found that plectin plays a significant role in organizing all cytoskeletal elements expressed in the cytoplasm of astrocytes. Furthermore, plectin is involved in astrocyte migration speed, as immortalized astrocytes devoid of plectin gene migrate slower than those expressing plectin. By labeling mitochondria, we showed that the shape of the mitochondrial network and the number of functional mitochondria differ in astrocytes devoid of plectin. We also measured increasing accumulation of reactive oxygen species in astrocytes devoid of plectin gene following stimulation with rotenone. Additionally, we observed that the organization of the Golgi apparatus and endoplasmic reticulum is altered in astrocytes devoid of plectin. In light of recent studies suggesting that plectin could serve as a marker for certain cancer types, we further evaluated the presence of plectin on the surface of astrocytes. We found that human glioblastoma cells express more surface plectin than primary human astrocytes, indicating potential use of plectin as a marker for glioblastoma. Moreover, in immortalized and primary mouse astrocytes lacking plectin, we observed a reduction in the amount and size of aquaporin 4 clusters on the plasma membrane, which impact astrocyte migration speed. In conclusion, we determined that plectin, through changes in the organization of various cytoskeletal elements, influences the arrangement and function of organelles in astrocytes and their migration. Forced expression of specific plectin isoforms in astrocytes with a knocked-out plectin gene improves the phenotype of these cells, bringing the values of analyzed parameters closer to the values measured in astrocytes expressing native plectin.
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