Glycated Collagen Decreased Endothelial Cell Fibronectin Alignment in Response to Cyclic Stretch Via Interruption of Actin Alignment

Abstract

Hyperglycemia is a defining characteristic of diabetes, and uncontrolled blood glucose in diabetes is associated with accelerated cardiovascular disease. Chronic hyperglycemia glycates extracellular matrix (ECM) collagen, which can lead to endothelial cell dysfunction. In healthy conditions, endothelial cells respond to mechanical stimuli such as cyclic stretch (CS) by aligning their actin cytoskeleton. Other cell types, specifically fibroblasts, align their ECM in response to CS. We previously demonstrated that glycated collagen inhibits endothelial cell actin alignment in response to CS. The aim of this study was to determine the effect of glycated collagen on ECM remodeling and protein alignment in response to stretch. Porcine aortic endothelial cells (PAEC) seeded on native or glycated collagen coated elastic substrates were exposed to 10% CS. Cells on native collagen aligned subcellular fibronectin fibers in response to stretch, whereas cells on glycated collagen did not. The loss of fibronectin alignment was due to inhibited actin alignment in response to CS, since fibronectin alignment did not occur in cells on native collagen when actin alignment was inhibited with cytochalasin. Further, while ECM protein content did not change in cells on native or glycated collagen in response to CS, degradation activity decreased in cells on glycated collagen. Matrix metalloproteinase 2 (MMP-2) and membrane-associated type 1 matrix metalloproteinase (MT1-MMP) protein levels decreased, and therefore MMP-2 activity also decreased. These MMP changes may relate to c-Jun N-terminal kinase (Jnk) phosphorylation inhibition with CS, which has previously been linked to focal adhesion kinase (FAK). These data demonstrate the importance of endothelial cell actin tension in remodeling and aligning matrix proteins in response to mechanical stimuli, which is critical to vascular remodeling in health and disease.

Mechanical Injury Induces Brain Endothelial-Derived Microvesicle Release: Implications for Cerebral Vascular Injury during Traumatic Brain Injury

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Advanced glycation end-products regulate extracellular matrix-adipocyte metabolic crosstalk in diabetes

“…Unglycated or glycated recombinant human collagen 1 was added to culture media in soluble form for 2D culture. For glycation, recombinant human collagen 1 (Rockland Immunochemicals, Inc., Limerick, PA, USA, Cat#009-001-103) was incubated in 100 μg/ml with 500 mM D-glucose-6-phosphate in PBS, 4 weeks, 37 °C, and used at 20 μg/ml in culture, based on previously published methods 69 , as well as dose response studies we performed studying concentrations ranging from 20–100 μg/ml that demonstrated 20 μg/ml provided maximal effect on adipocyte glucose uptake.…”

Problem-Based Learning in Biomechanics: Advantages, Challenges, and Implementation Strategies

“…For faculty actively engaged in research, real-world context can also be found in research papers or in the laboratory. For example, the authors previously based problems on endothelial cell response to flow and cyclic strain in diabetic conditions [17,18]. These types of problems can be simple to create and implement, since faculty already ground their research in clinical problems, and the techniques and sample data are readily available.…”