The "artificial artery" as in vitro perfusion model.

Area of Science:

• Biomedical Engineering
• Vascular Biology
• Cardiovascular Research

Background:

• Fluid shear stress (FSS) is a key mediator of vascular plasticity and arteriogenesis.
• Understanding cellular responses to FSS is crucial for developing treatments for cardiovascular diseases.
• Existing models often lack the complexity to fully replicate in vivo vascular environments.

Purpose of the Study:

• To develop and characterize an in vitro bioreactor, termed the "artificial artery," that mimics physiological arterial flow conditions.
• To investigate cell-specific interactions and molecular mechanisms under laminar FSS.
• To establish a platform for screening arterio-protective and pro-arteriogenic substances.

Main Methods:

• Co-culturing human umbilical vein endothelial cells (HUVECs) and human umbilical artery smooth muscle cells (HUASMCs) on hollow fiber membranes within a bioreactor.
• Applying defined laminar FSS conditions (0.1 N/m2 and 3 N/m2) and metabolic exchange.
• Utilizing Hoechst 33342 staining, immunocytochemistry, MALDI-TOF-TOF mass spectrometry, qRT-PCR, and gene expression analysis (KLF2, TIMP1, EDN1, VWF, CCND1).

Main Results:

• The
• artificial artery
• successfully maintained cell viability and viability for up to five days.
• Laminar FSS induced upregulation of mechano-regulated genes (KLF2, TIMP1) and downregulation of EDN1, indicating homeostatic conditions.
• HUVECs secreted Up4A under higher FSS (3 N/m2), and CCND1 expression remained unchanged, suggesting a quiescent endothelial phenotype.

Conclusions:

• The
• artificial artery
• bioreactor is a robust in vitro model for studying vascular responses to FSS.
• This model can be used to evaluate the impact of pharmacological compounds on vascular health and disease.
• It provides insights into molecular mechanisms underlying arteriogenesis and vascular plasticity.