Matrix-embedded endothelial cells are protected from the uremic milieu.

Area of Science:

• Biomedical Engineering
• Vascular Biology
• Nephrology

Background:

• Endothelial cells (ECs) in 3D matrices (MEECs) preserve vascular access patency.
• MEEC efficacy relies on EC health, which is compromised by the uremic environment.
• Uremia inhibits EC proliferation and promotes apoptosis, necessitating investigation into MEEC responses.

Purpose of the Study:

• To determine if uremia impacts matrix-embedded endothelial cells (MEECs).
• To compare the viability and function of MEECs versus 2D-cultured ECs in uremic serum.
• To assess the protective mechanisms of matrix embedding against uremic toxicity.

Main Methods:

• ECs cultured in 2D (gTCPS) or 3D (MEEC) were exposed to pooled sera from healthy or uremic patients.
• EC viability assessed via MTT assay, cell counting, and Trypan blue exclusion.
• Conditioned media (CM) effects on vascular smooth muscle cell (vSMC) proliferation measured via [3H] thymidine incorporation and cyclin D1 expression.

Main Results:

• Uremic serum reduced viability of 2D ECs but not MEECs.
• MEECs demonstrated preserved EC survival and enhanced inhibition of vSMC proliferation compared to 2D ECs.
• Matrix filtration experiments indicated ECs' intrinsic changes, not toxin retention, mediate protection.

Conclusions:

• MEECs exhibit preserved viability and efficacy in uremic serum, unlike 2D ECs.
• Matrix embedding intrinsically protects ECs from uremic toxicity.
• MEECs are a robust cell protectant, promising for preventing neointimal hyperplasia at vascular access sites in uremic patients.