Deletion of the cell adhesion adaptor protein vinculin disturbs the localization of GFAP in Bergmann glial cells

Abstract

Astrocytes operate in close spatial relationship to other cells including neurons. Structural interaction is controlled by a dynamic interplay between actin-based cell motility and contact formation via cell-cell and cell-extracellular matrix adhesions. A central player in the control of cell adhesion is the cytoskeletal adaptor protein Vinculin. Incorporation of Vinculin affects mechanical properties and turnover of cell adhesion sites. To study the in vivo function of Vinculin in astrocytes, a mouse line with astrocyte specific and inducible deletion of vinculin was generated. Deletion of vinculin decreased the expression of the glial acidic fibrillary protein (GFAP) in Bergmann glial cells in the cerebellum. In addition, localization of GFAP to Bergmann glial endfeet was disturbed, indicating a role for vinculin in controlling its expression and localization. In contrast, vimentin expression, morphology, activation state and polarity of the targeted cells as well as the localization of the extracellular matrix protein laminin was not compromised. Furthermore, stab wound lesions were performed in the cerebellar cortex. In both wildtype and vinculin knockout mice GFAP expression was upregulated in Bergmann glial cells of the lesioned area with no differences observed between genotypes in expression and localization of GFAP. These results propose a selective requirement for vinculin in cellular events related to cell adhesion in vivo. As in vitro data suggested a major role for vinculin in the control of the cytoskeletal connection affecting mechanical stability and cell motility, our data add a note of caution to the extrapolation of in vitro data to in vivo function.

Proteomics of Huntington’s Disease-Affected Human Embryonic Stem Cells Reveals an Evolving Pathology Involving Mitochondrial Dysfunction and Metabolic Disturbances

“…Neural cells generated from HD-affected hESC demonstrated a vast network of cytoskeletal protein alteration and dysregulation, presumably leading to an overall reduction in cell motility and intracellular trafficking. Decreases in the cytoskeletal proteins radixin (RDX), myosin light chain 6 (MYL6) and IQ motif-containing GTPase activating protein 1 (IQGAP1) all suggested that HD neuronal cells were undergoing severe disruptions in axonal transport. − Talin-1, vinculin, and α-actinin are known to be intimately involved in the creation and maintenance of focal adhesions, the anchoring of cytoskeleton to the extracellular matrix (ECM) and critical for cell motility/migration, as well as response to the ECM environment. Reductions of profilin1 is associated with impaired formation of focal adhesions.…”

Gray and white matter astrocytes differ in basal metabolism but respond similarly to neuronal activity

“…About 45 μm thick vibratome sections were prepared and stained for the pan‐astrocyte marker 3‐phosphoglycerate dehydrogenase (3PGDH; Yamasaki et al, 2001) using a guinea pig anti‐3PGDH antibody (1:200, Frontier Institute, Ishikari, Hokkaido, Japan) and a donkey anti guinea pig CF633 (1:250, Sigma‐Aldrich) in combination with a goat anti‐GFP (Biotin conjugated) antibody (1:200, Rockland Immunochemicals, Pottstown, PA) and Streptavidin‐Cy2 (1:500, Dianova, Hamburg, Germany). The staining protocol was previously described in detail (Winkler et al, 2013). Sections were mounted in ImmunoSelect Antifading Mounting Medium DAPI (Dianova).…”

Important Shapeshifter: Mechanisms Allowing Astrocytes to Respond to the Changing Nervous System During Development, Injury and Disease

“…In cell culture, the actin cytoskeleton directly governs the localization of aquaporin-4 (Nicchia et al, 2008 ). Deleting the focal adhesion adapter protein vinculin in Bergmann glia disturbs the GFAP distribution in endfeet but has no obvious effect on neurovascular functions (Winkler et al, 2013 ).…”