Abstract: SA-PO0502
High-Salt-Exposed Immune Cells Inhibit Renal Lymphangiogenesis: Role of VEGFR3 Shedding
Session Information
- Fluid, Electrolyte, and Acid-Base Disorders: Basic Research
November 08, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Fluid, Electrolytes, and Acid-Base Disorders
- 1101 Fluid, Electrolyte, and Acid-Base Disorders: Basic
Authors
- Liu, Jing, Vanderbilt University Medical Center, Nashville, United States
- Zhong, Jianyong, Vanderbilt University Medical Center, Nashville, Tennessee, United States
- Yang, Haichun, Vanderbilt University Medical Center, Nashville, Tennessee, United States
- Shelton, Elaine L., Vanderbilt University Medical Center, Nashville, Tennessee, United States
- Kirabo, Annet, Vanderbilt University Medical Center, Nashville, Tennessee, United States
- Kon, Valentina, Vanderbilt University Medical Center, Nashville, Tennessee, United States
Background
The lymphatic system is critical in maintaining kidney homeostasis. Previously, we showed that excess Na+ affects vascular and immune functions, although impact on immune cell-mediated lymphangiogenesis is unclear. This is important in view of the recent evidence that immune cells retain "memory" of past environmental exposures that direct their interactions once conditions are normalized. We discussed how elevated sodium preconditioned splenocytes retain memory that alters their interaction with lymphatic endothelial cells(LECs), independent of direct Na+ exposure.
Methods
Rats splenocytes were maintained in normal(145mM,NS) or high Na+(190mM,HS)24 hours, then adoptively transferred into puromycin aminonucleoside nephrosis(PAN)-injured rats. Renal lymphangiogenesis was assessed. In vitro,splenocytes exposed to NS or HS then normal medium, were co-culture with LECs. LEC proliferation and tube formation assays measured lymphangiogenic potential and assessed apoptosis effects.
Results
HS-repleted PAN rats had more severe proteinuria, increased histologic kidney damage, and greater infiltration of macrophages compared to NS-PAN rats. Unexpectedly, lymphangiogenesis was significantly less in HS-PAN vs NS-PAN.In vitro, LECs cocultured with HS-pretreated splenocytes showed decreased proliferation and impaired tube formation compared to LECs co-cultured with NS-pretreated splenocytes, without changes in Bcl2/Bax.Notably, VEGFC expression was elevated in both kidneys of HS-PAN rats and in supernatant of HS-pretreated splenocytes, suggesting LEC not responsive to VEGFC.Then VEGFR3 was found to be shed in LECs cocultured with HS-pretreated splenocytes, demonstrated by decreased VEGFR3 ectodomain levels in cell lysates and increased soluble VEGFR3 in supernatant.HS-stimulated splenocytes released more MMP2,a likely upstream of VEGFR3 shedding. Indeed,inhibition of MMP2 with specific inhibitor recovered VEGFR3 shedding, cell proliferation and tube formation in LECs cocultured with HS-pretreated splenocytes.
Conclusion
Although HS stimulates expression of VEGFC,the concurrent shedding of its receptor,VEGFR3,results in inhibited lymphangiogenesis. We found a novel immune cell memory-driven mechanism that impairs LV proliferation in proteinuric disease,providing new insights into the interplay among sodium,immune regulation and lymphangiogenesis.
Funding
- NIDDK Support