Substratum interactions modulate interplay between endothelial cell, epithelial cell, and fibroblast phenotype and...

Area of Science:

• Cell Biology
• Biomaterials Science
• Immunology

Background:

• Endothelial cells (ECs) are vital for vascular homeostasis but lose in vivo characteristics in standard 2D culture.
• Substratum interactions significantly influence cellular phenotypes, yet in vitro models often fail to capture this microenvironmental complexity.

Purpose of the Study:

• To investigate how different culture conditions (2D vs. 3D) impact endothelial cell phenotype and function.
• To compare the responsiveness of ECs to culture conditions versus other cell types like epithelial cells and fibroblasts.
• To evaluate the effect of culture conditions on immunomodulatory factor expression and in vivo immune responses.

Main Methods:

• Culturing endothelial cells, epithelial cells, and fibroblasts in 2D (tissue culture polystyrene) and 3D (collagen scaffolds) environments.
• Analyzing cellular responses to hypoxic gradients, including HIF1-a expression and endothelial-to-mesenchymal transition.
• Assessing the expression of immunomodulatory factors.
• Utilizing an in vivo allotransplantation model to evaluate immune cell cytotoxicity.

Main Results:

• 3D culture on collagen scaffolds significantly altered EC phenotype compared to 2D culture, more so than cell source.
• 3D ECs upregulated HIF1-a in response to hypoxia, while 2D ECs underwent endothelial-to-mesenchymal transition.
• Culture conditions differentially affected immunomodulatory factor expression across cell types.
• 3D culture reduced host immune cell cytotoxicity in an in vivo allotransplantation model for all tested cell types.

Conclusions:

• Endothelial cells exhibit unique responses to their microenvironment, differing from epithelial cells and fibroblasts.
• Traditional 2D culture is inadequate for studying in vivo EC behavior and function.
• 3D culture systems offer a more physiologically relevant model for ECs, impacting both cellular function and immune interactions relevant to transplantation.