Rejuvenated endothelial progenitor cells through overexpression of cellular prion protein effectively salvaged the critical limb ischemia in rats with preexisting chronic kidney disease

Stem Cell Res Ther. 2022 Sep 2;13(1):447. doi: 10.1186/s13287-022-03119-0.

Abstract

Background: This study tested the hypothesis that overexpression of cellular prion protein in endothelial progenitor cells (PrPcOE-EPCs), defined as "rejuvenated EPCs," was superior to EPCs for salvaging the critical limb ischemia (CLI) induced after 28-day chronic kidney disease (CKD) induction in rat.

Methods and results: Cell viability and flow cytometric analyses of early/late apoptosis/total-intracellular ROS/cell cycle (sub-G1, G2/M phase) were significantly higher in EPCs + H2O2 than in EPCs that were significantly reversed in PrPcOE-EPCs + H2O2 (all p < 0.001). The protein expressions of inflammation (IL-1ß/IL-6/MMP-9/p-NF-κB) were significantly increased in EPC + TNF-α than in EPCs that were significantly reversed in PrPcOE-EPCs + TNF-α (all p < 0.001). Adult-male SD rats (n = 8/each group) were categorized into group 1 (sham-operated control), group 2 (CKD + CLI), group 3 [CKD + CLI + EPCs by intravenous (0.6 × 105)/intra-muscular (0.6 × 105) injections at 3 h after CLI induction], group 4 (CKD + CLI + PrPcOE-EPCs/dose-administration as group 3) and group 5 (CKD + CLI + siPrnp-EPCs/dose-administration as group 3). By day 14 after CLI induction, the ratio of ischemia to normal blood flow (INBF) in CLI area was highest in group 1/lowest in group 2/significantly higher in group 4 than in groups 3/5 and significantly higher in group 3 than in group 5 (all p < 0.0001). Histopathology demonstrated that the angiogenesis (number of small vessels/CD31 + cells) exhibited a similar trend, whereas the fibrosis/kidney injury score exhibited an opposite pattern of INBF among the groups (all p < 0.0001). The protein expressions of angiogenesis (SDF-1α/VEGF/CXCR4)/cell-stress signaling (p-PI3K/p-Akt/p-m-TOR) were significantly and progressively increased from groups 1-4 that were reversed in group 5 (all p < 0.0001). The protein expressions of fibrotic (p-Smad3/TGF-ß)/oxidative-stress (NOX-1/NOX-2/oxidized-protein)/apoptotic (mitochondrial-Bax/cleaved caspase3/cleaved PARP)/mitochondrial-damaged (cytosolic-cytochrome-C) biomarkers displayed an opposite pattern of INBF among the groups (all p < 0.0001).

Conclusion: PrPcOE-EPCs were superior to EPCs only therapy for salvaging the CLI.

Keywords: Chronic kidney disease; Critical limb ischemia; Endothelial progenitor cells; Rejuvenation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chronic Limb-Threatening Ischemia
  • Endothelial Progenitor Cells* / metabolism
  • Fibrosis
  • Hydrogen Peroxide / pharmacology
  • Ischemia / pathology
  • Male
  • Neovascularization, Pathologic / metabolism
  • Prion Proteins / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Renal Insufficiency, Chronic* / pathology
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • Prion Proteins
  • Tumor Necrosis Factor-alpha
  • Hydrogen Peroxide