Abstract: SA-PO0320
High Glucose Inhibits Angiogenesis via Semaphorin-Plexin-Mediated Cross-Talk Between Endothelial and Proximal Tubule Cells
Session Information
- Diabetic Kidney Disease: Basic and Translational Science Advances - 2
November 08, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Diabetic Kidney Disease
- 701 Diabetic Kidney Disease: Basic
Authors
- Kaur, Geetika, Henry Ford Health System, Detroit, Michigan, United States
- Patil, Sushmita R, Wayne State University School of Medicine, Detroit, Michigan, United States
- Bahmani, Azadeh, Henry Ford Health System, Detroit, Michigan, United States
- Caceres, Paulo S., Henry Ford Health System, Detroit, Michigan, United States
Background
Microvasculature loss in the diabetic kidney has been documented but is poorly understood. The proximal tubule has the potential of regulating angiogenesis via secretion of paracrine factors, like VEGF, but the relevance of this in diabetes is unknown. We have shown increased kidney Semaphorins expression (anti-angiogenic) in diabetic mice. However, the role of proximal tubule semaphorin-mediated regulation of angiogenesis in diabetic kidney is an open question.
Hypothesis: High glucose stimulates semaphorins in proximal tubule, which inhibit endothelial cell angiogenesis.
Methods
The angiogenic properties of conditioned media from polarized RPTEC proximal tubule cells was analyzed in endothelial HUVEC cells in Matrigel. We assessed surface expression of angiogenic receptors in kidney endothelial primary cultures of diabetic Akita mice.
Results
The basolateral conditioned media from RPTEC cells stimulated HUVEC angiogenesis (15.8±1.8 vs. 20±2 loops/field). However, media from RPTEC cells on high glucose (25 mM) did not (8.4±1.8 loops/field). Apical media did not have any effect. Similarly, high glucose-conditioned media failed to stimulate HUVEC migration in wound healing assays (0.039±0.003 vs. 0.019±0.002 mm2/hr). To study the role of a semaphorin receptor, we silenced Plexin-D1 via shRNAs and found that migration was stimulated by high glucose-conditioned media (0.059±0.003 mm2/hr). Next, we studied the role of a Plexin ligand Semaphorin-3D (Sema3D). We silenced Sema3D in RPTEC cells, and observed that high glucose-conditioned media lost their ability to inhibit angiogenesis (12±1.4 vs. 4.4±1 loops/field). Finally, to study whether Sema-Plexin signaling may be enhanced in diabetic kidneys, we measure surface expression of Plexin-D1 in primary cultures of kidney endothelial cells from Akita mice. We found that surface Plexin-D1 expression was 305±63% higher vs. wt, and stimulated by VEGF only in Akita by 109±23%. Surface VEGFR2 receptor was not different between wt and Akita, and it was increased by VEGF only in wt (41±15%).
Conclusion
High glucose-conditioned medium from RPTEC proximal tubule cells inhibits HUVEC angiogenesis via secretion of Sema3D, a ligand for Plexin-D1, which was increased by VEGF in kidney endothelial cells from diabetic Akita mice.
Funding
- NIDDK Support