Engineering microvascular networks using a KLF2 reporter to probe flow-dependent endothelial cell function

Adriana Blazeski; Marie A Floryan; Yuzhi Zhang; Oscar R Fajardo Ramírez; Elamaran Meibalan; Jesús Ortiz-Urbina; Emmanouil Angelidakis; Sarah E Shelton; Roger D Kamm; Guillermo García-Cardeña

doi:10.1016/j.biomaterials.2024.122686

Engineering microvascular networks using a KLF2 reporter to probe flow-dependent endothelial cell function

Biomaterials. 2024 Dec:311:122686. doi: 10.1016/j.biomaterials.2024.122686. Epub 2024 Jun 25.

Affiliations

¹ Center for Excellence in Vascular Biology, Department of Pathology, Brigham and Women's Hospital, USA and Harvard Medical School, Boston, MA, USA; Cardiovascular Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA, USA; Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
² Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
³ Center for Excellence in Vascular Biology, Department of Pathology, Brigham and Women's Hospital, USA and Harvard Medical School, Boston, MA, USA.
⁴ Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
⁵ Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Medical Oncology, Dana Farber Cancer Institute, Boston, MA, USA.
⁶ Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
⁷ Center for Excellence in Vascular Biology, Department of Pathology, Brigham and Women's Hospital, USA and Harvard Medical School, Boston, MA, USA; Cardiovascular Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA, USA. Electronic address: guillermo_garcia-cardena@hms.harvard.edu.

PMID: 38971122
DOI: 10.1016/j.biomaterials.2024.122686

Abstract

Shear stress generated by the flow of blood in the vasculature is a potent regulator of endothelial cell function and vascular structure. While vascular responses to flow are complex and context-dependent, endothelial cell signaling in response to shear stress induced by laminar flows is coordinated by the transcription factor KLF2. The flow-dependent expression of KLF2 in endothelial cells is associated with a quiescent, anti-inflammatory phenotype and has been well characterized in two-dimensional systems but has not been studied in three-dimensional in vitro systems. Here we develop engineered microvascular networks (MVNs) that incorporate a KLF2-based endothelial cell flow sensor within a microfluidic chip, apply continuous flow using an attached microfluidic pump, and study the effects of this flow on vascular structure and function. We found that application of flow to MVNs for 48 h resulted in increased expression of the KLF2 reporter, larger vessel diameters, and decreased vascular branching and resistance. Notably, vessel diameters after the application of flow were independent of initial MVN morphologies. Finally, we found that MVNs exposed to flow have improved vascular barrier function and decreased platelet adhesion. MVNs with KLF2-based flow sensors represent a novel, powerful tool for evaluating the structural and functional effects of flow on engineered three-dimensional vascular systems.

Keywords: Engineered microvascular networks; Flow reporter; Flow sensors; Microfluidic chip; Shear stress.

MeSH terms

Animals
Endothelial Cells / cytology
Endothelial Cells / metabolism
Human Umbilical Vein Endothelial Cells / metabolism
Humans
Kruppel-Like Transcription Factors* / genetics
Kruppel-Like Transcription Factors* / metabolism
Microvessels* / cytology
Microvessels* / metabolism
Stress, Mechanical
Tissue Engineering* / methods

Substances

Kruppel-Like Transcription Factors
KLF2 protein, human