Endothelial glycocalyx sensitivity to chemical and mechanical sub-endothelial substrate properties

Mohammad Hamrangsekachaee; Ke Wen; Narges Yazdani; Rebecca K Willits; Sidi A Bencherif; Eno E Ebong

doi:10.3389/fbioe.2023.1250348

Endothelial glycocalyx sensitivity to chemical and mechanical sub-endothelial substrate properties

Front Bioeng Biotechnol. 2023 Oct 30:11:1250348. doi: 10.3389/fbioe.2023.1250348. eCollection 2023.

Authors

Mohammad Hamrangsekachaee¹, Ke Wen¹, Narges Yazdani², Rebecca K Willits^{1

2}, Sidi A Bencherif^{1

2

3

4}, Eno E Ebong^{1

2

5}

Affiliations

¹ Chemical Engineering Department, Northeastern University, Boston, MA, United States.
² Bioengineering Department, Northeastern University, Boston, MA, United States.
³ Laboratoire de BioMécanique et BioIngénierie (BMBI), UMR CNRS, Sorbonne Universités, Université de Technologie of Compiègne (UTC), Compiègne, France.
⁴ Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, United States.
⁵ Neuroscience Department, Albert Einstein College of Medicine, New York, NY, United States.

Abstract

Glycocalyx (GCX) is a carbohydrate-rich structure that coats the surface of endothelial cells (ECs) and lines the blood vessel lumen. Mechanical perturbations in the vascular environment, such as blood vessel stiffness, can be transduced and sent to ECs through mechanosensors such as GCX. Adverse stiffness alters GCX-mediated mechanotransduction and leads to EC dysfunction and eventually atherosclerotic cardiovascular diseases. To understand GCX-regulated mechanotransduction events, an in vitro model emulating in vivo vessel conditions is needed. To this end, we investigated the impact of matrix chemical and mechanical properties on GCX expression via fabricating a tunable non-swelling matrix based on the collagen-derived polypeptide, gelatin. To study the effect of matrix composition, we conducted a comparative analysis of GCX expression using different concentrations (60-25,000 μg/mL) of gelatin and gelatin methacrylate (GelMA) in comparison to fibronectin (60 μg/mL), a standard coating material for GCX-related studies. Using immunocytochemistry analysis, we showed for the first time that different substrate compositions and concentrations altered the overall GCX expression on human umbilical vein ECs (HUVECs). Subsequently, GelMA hydrogels were fabricated with stiffnesses of 2.5 and 5 kPa, representing healthy vessel tissues, and 10 kPa, corresponding to diseased vessel tissues. Immunocytochemistry analysis showed that on hydrogels with different levels of stiffness, the GCX expression in HUVECs remained unchanged, while its major polysaccharide components exhibited dysregulation in distinct patterns. For example, there was a significant decrease in heparan sulfate expression on pathological substrates (10 kPa), while sialic acid expression increased with increased matrix stiffness. This study suggests the specific mechanisms through which GCX may influence ECs in modulating barrier function, immune cell adhesion, and mechanotransduction function under distinct chemical and mechanical conditions of both healthy and diseased substrates.

Keywords: endothelial cells; gelatin-based hydrogel; glycocalyx; mechanotransduction; substrate stiffness.

Abstract

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