Kidney Week

Abstract: FR-PO935

Effect of Hypoxia on Subpopulations of Cells During Kidney Development

Session Information

• Development, Stem Cells, Regenerative Medicine - II
  October 26, 2018 | Location: Exhibit Hall, San Diego Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Development, Stem Cells, and Regenerative Medicine

• 501 Development, Stem Cells, and Regenerative Medicine: Basic

Authors

• Hauser, Peter V., Greater Los Angeles Veterans Administration, Los Angeles, California, United States

Peter V. Hauser,

• Hamon, Morgan, Greater Los Angeles Veterans Administration, Los Angeles, California, United States

Morgan Hamon,

• Zhao, Lifu, Sepulveda Research Corporation, North Hills, California, United States

Lifu Zhao,

• Nishikawa, Masaki, Greater Los Angeles Veterans Administration, Los Angeles, California, United States

Masaki Nishikawa,

• Yanagawa, Naomi, Sepulveda Research Corporation, North Hills, California, United States

Naomi Yanagawa,

• Yanagawa, Norimoto, Greater Los Angeles Veterans Administration, Los Angeles, California, United States

Norimoto Yanagawa,

Background

During early developmental stages, embryonic kidneys are not fully vascularized and exposed to hypoxic condition (HC). HC is known to influence cell proliferation and survival, ureteric bud (UB) branching and vascularization of the developing kidney. We aimed in our present study to gain further insight into the effect of HC on different subpopulations of cells in embryonic kidneys at early developmental stages.

Methods

E11.5-13.5 embryonic kidneys were obtained from Hoxb7^Venus, Foxd1^GFP, Six2^EGFP,Cited1^RFPmice and cultured under either HC or normal condition (NC) for up to 120h. Cell viability and gene expression pattern of Hoxb7⁺, FoxD1⁺, Six2⁺and Cited1⁺cells were analyzed by flow cytometry and q-RT-PCR, respectively. UB branching morphogenesis was analyzed under confocal microscopy to generate 3D images for measurements of organ volume, branching generations, branching length and diameter by using a gradient vector based software (TreeSurveyor).

Results

We found that HC reduced overall cell viability after 24, 48, 72, 96 and 120h. However, as compared to Foxd1⁺stromal cells and Six2⁺metanephric mesenchymal (MM) cells, Hoxb7⁺UB cells and Cited1⁺MM cells were less susceptible to HC and showed reduced cell death after 48, 72, and 96h. HC increased the number of branching generations in E12.5 and E13.5 kidneys after 24h and decreased at 48 and 72h, while E11.5 kidneys were not affected. HC further increased the length and diameter of UB branches in E13.5 kidneys at 24h but not at 48 and 72h. HC increased HIF1a mRNA levels in E12.5 kidneys at 48h and 72h, but normalized at 96h. HC also upregulated the mRNA levels of angiotensinogen at 24h, 48h and 72h, renin and angiotensin receptor 2 at 72h, while angiotensin receptor 1 was unchanged.

Conclusion

We conclude that HC imposes different effects on different subpopulations of cells in embryonic kidneys at different developmental stages. Studies are ongoing to further characterize the effects of HC on different subpopulations of cells during kidney development.

Funding

• Private Foundation Support