Basement Membrane Proteins Influence Brain Capillary Endothelial Barrier Function In Vitro

Abstract

Abstract:The influence of basement membrane proteins on cellular barrier properties of primary cultures of porcine brain capillary endothelial cells grown on permeable filter inserts has been investigated. Measurements of transcellular electrical resistance (TEA) by impedance spectroscopy were performed with cells cultured on type IV collagen, fibronectin, laminin, and one-to-one mixtures of these proteins. Moreover, a one-to-one combination of type IV collagen and SPARC (secreted protein acidic and rich in cysteine) has been studied. Rat tail collagen has been used as a reference substratum. If TERs of cells from a given preparation were low (-~350Q x cm 2) on the reference substratum, type IV collagen, fibronectin, and laminin as well as one-to-one combinations of these proteins elevated transcellular resistances significantly (2.3-to 2.9-fold) compared with rat tail collagen. TER of cells exhibiting a high reference level (~-~1 000~l x cm2) could, by contrast, be increased only 1.1-to 1.2-fold. The type IV collagen/SPARC mixture did not elevate TER. Our findings suggest that type IV collagen, fibronectin, and laminin are involved in tight junction formation between cerebral capillary endothelial cells. The differential effects observed for individual preparations probably reflect more or less dedifferentiated states of the endothelium, in which basement membrane proteins can influence cellular differentiation more or less strongly. However, our results indicate that type IV collagen, fibronectin, and laminin enhance the reliability and suitability of primary microvascular endothelial cell cultures as an in vitro model of the blood-brain barrier. Key Words: Bloodbrain barrier-Primary cell culture-Transcellular electrical resistance-Basement membrane proteins-Extracellular matrix.

The Blood-Brain Barrier/Neurovascular Unit in Health and Disease

“…Such cell-matrix interactions can stimulate a number of intracellular signaling pathways (reviewed in Tilling et al, 2002). Matrix proteins can influence the expression of endothelial TJ proteins (Tilling et al, 1998;Savettieri et al, 2000), indicating that although the TJ constitute the primary impediment to paracellular diffusion, the proteins of the basal lamina are likely involved in their maintenance.…”

Astrocytes in culture express fibrillar collagen

“…Collagens play critical roles in the CNS, for example, in maintaining the integrity of the blood-brain barrier (Tilling et al, 1998). However, the properties given to the tissue by the collagens are not restricted to their structural roles in the basement membrane.…”

Blood-Brain Barrier and Effectiveness of Therapy Against Brain Tumors

“…To achieve this aim different techniques have been recruited, e.g. utilizing of the hydrocortisone and serum free medium in order to increase the TEER (up to 1000 cm 2 ) by stimulating the formation of barrier properties (Hoheisel et al 1998). …”

“…The ECs in general do not express their final destination-specific differentiated features until those features are induced by local environment-produced conditions including extracellular matrix. Using primary cultures of PBCECs, Tilling et al (1998) examined the effect of collagen IV, fibronectin, laminin and a secreted acidic protein and rich in cysteine alone or one-to-one mixtures of them. They showed that these proteins are involved in tight junction formation between cerebral capillary endothelial cells by presenting increased TEER (Robert & Robert, 1998;Tilling et al, 1998).…”