Data from: Regeneration of glycocalyx by heparan sulfate and sphingosine 1-phosphate restores inter-endothelial communication

Vasculoprotective endothelium glycocalyx (GCX) shedding plays a critical
role in vascular disease. Previous work demonstrated that GCX degradation
disrupts endothelial cell (EC) gap junction connexin (Cx) proteins, likely
blocking interendothelial molecular transport that maintains EC and
vascular tissue homeostasis to resist disease. Here, we focused on GCX
regeneration and tested the hypothesis that vasculoprotective EC function
can be stimulated via replacement of GCX when it is shed. We used EC with
[i] intact heparan sulfate (HS), the most abundant GCX component; [ii]
degraded HS; or [iii] HS that was restored after enzyme degradation, by
cellular self-recovery or artificially. Artificial HS restoration was
achieved via treatment with exogenous HS, with or without the GCX
regenerator and protector sphingosine 1- phosphate (S1P). In these cells
we immunocytochemically examined expression of Cx isotype 43 (Cx43) at EC
borders and characterized Cx-containing gap junction activity by measuring
interendothelial spread of gap junction permeable Lucifer Yellow dye. With
intact HS, 60% of EC borders expressed Cx43 and dye spread to 2.88 ± 0.09
neighboring cells. HS degradation decreased Cx43 expression to 30% and
reduced dye spread to 1.87± 0.06 cells. Cellular self-recovery of HS
restored baseline levels of Cx43 and dye transfer. Artificial HS recovery
with exogenous HS partially restored Cx43 expression to 46% and yielded
dye spread to only 1.03 ± 0.07 cells. Treatment with both HS and S1P,
recovered HS and restored Cx43 to 56% with significant dye transfer to
3.96 ± 0.23 cells. This is the first evidence of GCX regeneration in a
manner that effectively restores vasculoprotective EC communication.