Abstract: PO0880
CD133+ Progenitor Cells in Proximal Tubules Are Most Likely the First Responding Cells to Acute Tubular Injury in Human Kidneys
Session Information
- Development, Stem Cells, and Regenerative Medicine
October 22, 2020 | Location: On-Demand
Abstract Time: 10:00 AM - 12:00 PM
Category: Development, Stem Cells, and Regenerative Medicine
- 500 Development, Stem Cells, and Regenerative Medicine
Authors
- Yin, Wenqing, Boston Medical Center, Boston, Massachusetts, United States
- Zhang, Ping L., Beaumont Health, Royal Oak, Michigan, United States
Background
Proximal tubules (PT) are mainly used for the reabsorption of electrolytes and fluid. Recent studies reveal CD133+ progenitor cells scattered along the PT, and CD133 wrapped in extracellular vesicles (EV) of urine can be used as an injury biomarker. The main goal of the study was to investigate how CD133+ progenitor cells are distributed along the convulated PT and whether CD133+ progenitor cells are related to initial repairing of PT.
Methods
Ten early metanephrons, 10 control adult renal sections and 40 renal biopsies with various degrees of acute tubular injury (ATI) were stained CD133 for highlighting progenitor cells of PT, followed by special Periodic Acid Schiff (PAS) staining for identifying brush borders. The dual stains sections fo evaluate surface CD133 expression and PAS positive brush borders were evaluated by light microscopy.
Results
CD133 staining was positive in the renal S shape body, parietal epithelium of primordial glomeruli, distal tubules and focally positive in PT of early metanephros. The control adult nephron revealed single CD133+ progenitor cells at the U turn niches of convoluted PT, which were stained negatively for PAS, indicating that CD133+ progenitor cells may watch turning segments (convoluted loops) of PT and do not have reabsorption capacity. At the early stage of ATI, there were side-by-side and nearby dual or triple CD133+ cells in each cross section of PT, which were negative for PAS staining as well. Surface CD133+ micro-granules of proximal tubules were identified in the early injured PT.
Conclusion
Our data indicate that CD133 in parietal epithelium and renal tubules are most likely derived from the condensing mesenchymal cells/S-shaped body after the induction of ureteric bud in the metanephros. There are two types of cells in proximal tubules – classic PT cells with brush borders for reabsorption and scattered CD133+ progenitor cells that are lack of brush borders and may serve as “ injury watchdog” at each turning segment of convoluted PT. During early ATI, dual or triple CD133+ cells were present, implying that CD133+ progenitor cells may represent the first responding cells to acute tubular injury for tubular repairing. CD133+ micro-particles were present at the surface of injured PT imply that CD133+ progenitor cells may pass the CD133+ EV to signal surrounding cells for the injury insult.