Supplementary Material for: Intussusceptive Pillar Formation in Developing Porcine Glomeruli

Background/Aims: Intussusceptive angiogenesis (IA) is a dynamic process which contributes to vascular expansion and remodeling. Intraluminal pillars have long been the distinctive structural indicator of IA. However, the mechanism of their formation has not been fully elucidated. Methods: Using light and electron microscopy, we studied intussusceptive vascular growth in the developing porcine metanephric kidney. Results: We observed intraluminal pillars formed by endothelial cells in the vasculature of developing glomeruli. Their diameter was Conclusion: This study shows ECM presence in a mature intussusceptive pillar without any perivascular cell involvement in the structure. This leads to the hypothesis that ECM deposition precedes the participation of these cells in the formation of intraluminal pillars during IA in porcine metanephric glomerular capillaries.