Endothelial cell contraction increases Candida adherence to exposed extracellular matrix

Area of Science:

• Cell biology
• Microbiology
• Immunology

Background:

• Endothelial cells form a barrier crucial for tissue homeostasis.
• Disruptions in endothelial cell integrity can lead to pathogen adhesion and invasion.
• The subendothelial extracellular matrix (ECM) plays a role in cell adhesion and signaling.

Purpose of the Study:

• To investigate the effect of endothelial cell contraction on yeast adherence.
• To determine if exposure of the subendothelial ECM mediates increased fungal binding.
• To differentiate between adherence mediated by cell shape changes versus ECM exposure.

Main Methods:

• Bovine vascular endothelial cells were treated with EDTA, urea, or thrombin to induce contraction.
• Cell monolayers were assessed for contraction and exposure of the subendothelial ECM.
• Adherence of Candida yeasts (C. albicans, C. tropicalis) and Pseudomonas aeruginosa was quantified.
• Cells treated with forskolin were used as a control for shape changes without ECM exposure.

Main Results:

• EDTA, urea, or thrombin induced reversible endothelial cell contraction and ECM exposure.
• Contracted monolayers showed significantly higher adherence of Candida yeasts compared to confluent monolayers (P < 0.01).
• Candida species avidly bound to the exposed ECM, while Pseudomonas aeruginosa did not.
• Forskolin treatment, causing cell shape changes without ECM exposure, did not increase yeast adherence.

Conclusions:

• Endothelial cell contraction and subsequent exposure of the subendothelial ECM promote Candida yeast adherence.
• The exposed ECM is a preferential binding site for Candida species.
• Increased adherence is specifically linked to ECM exposure, not just altered endothelial cell morphology.