Fig. 2.

Delayed execution of actin cytoskeleton rearrangements and impaired cell migration of primary plectin 1-deficient fibroblasts. (A) Immunofluorescence microscopy of wild-type and plectin 1 (–/–) fibroblasts visualizing the actin cytoskeleton and vinculin-positive FACs. After an attachment period of 2 or 24 h, cells were fixed and stained with antibodies indicated. Note statistically significant (60 randomly chosen cells were analyzed) increases in actin stress fibers and FACs in plectin 1 (–/–) cells after 2 h of spreading, whereas after 24 h, hardly any differences compared to wild-type cells were noticeable. (Scale bar: 20 μm.) (B) In vitro wound healing assay to measure migration of primary wild-type and plectin 1 (–/–) fibroblasts. Values represent means ± SD of six measurements per time point in three independent experiments. (C and D) Chemotactic (C) and random (D) migration of wild-type and plectin 1 (–/–) fibroblasts assayed by using a Boyden chamber. Measurements in C were carried out after a 24 h exposure to the chemoattractant (means ± SD, n = 3). Note just slight differences between wild-type and plectin 1 (–/–) cell populations passing through the filter in random migration (without chemoattractant) compared to a 47% difference in PDGF-directed migration. (E) Growth curves of wild-type and plectin 1-deficient fibroblasts (±SD, n = 4).