PDGFRA in vascular adventitial MSCs promotes neointima formation in arteriovenous fistula in chronic kidney disease
Ke Song, Ying Qing, Qunying Guo, Eric K. Peden, Changyi Chen, William E. Mitch, Luan Truong, Jizhong Cheng
Ke Song, Ying Qing, Qunying Guo, Eric K. Peden, Changyi Chen, William E. Mitch, Luan Truong, Jizhong Cheng
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Research Article Nephrology Stem cells

PDGFRA in vascular adventitial MSCs promotes neointima formation in arteriovenous fistula in chronic kidney disease

Abstract

Chronic kidney disease (CKD) induces the failure of arteriovenous fistulas (AVFs) and promotes the differentiation of vascular adventitial GLI1-positive mesenchymal stem cells (GMCs). However, the roles of GMCs in forming neointima in AVFs remain unknown. GMCs isolated from CKD mice showed increased potential capacity of differentiation into myofibroblast-like cells. Increased activation of expression of PDGFRA and hedgehog (HH) signaling were detected in adventitial cells of AVFs from patients with end-stage kidney disease and CKD mice. PDGFRA was translocated and accumulated in early endosome when sonic hedgehog was overexpressed. In endosome, PDGFRA-mediated activation of TGFB1/SMAD signaling promoted the differentiation of GMCs into myofibroblasts, extracellular matrix deposition, and vascular fibrosis. These responses resulted in neointima formation and AVF failure. KO of Pdgfra or inhibition of HH signaling in GMCs suppressed the differentiation of GMCs into myofibroblasts. In vivo, specific KO of Pdgfra inhibited GMC activation and vascular fibrosis, resulting in suppression of neointima formation and improvement of AVF patency despite CKD. Our findings could yield strategies for maintaining AVF functions.

Authors

Ke Song, Ying Qing, Qunying Guo, Eric K. Peden, Changyi Chen, William E. Mitch, Luan Truong, Jizhong Cheng

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Figure 4

PDGFRA is required for GMCs to differentiate into myofibroblasts.

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PDGFRA is required for GMCs to differentiate into myofibroblasts. (A) GL...
(A) GLI1CreERt2 mice were crossed with PDGFRAfl/fl mice to generate GLI1CreERt2/PDGFRAfl/fl mice (GMCPA–/– mice). (B) Representative Western blot (WB) of indicated proteins in both Ctl and Pdgfra-KO GMCs after treatment with PDGFA (10 ng/mL) for different times. (C–E) Representative images of WB showed that PDGFA time-dependently stimulated expression of PDGFRA and myofibroblast markers, S100A4, α-SMA, and VIM. In contrast, Pdgfra KO blocked PDGFA-induced promyogenic responses. Protein expression was normalized to GAPDH and expressed as fold change of Ctl GMCs (D and E). (F) Representative WB images of indicated signaling molecules in both Ctl and Pdgfra-KO GMCs after treatment with TGFB1 (2 ng/mL) for different times. Phosphorylation of SMAD2/3 and AKT1 present a parabolic change after TGFB1 treatment, whereas TGFB1-induced phosphorylation of SMAD2/3 and AKT were blocked in Pdgfra-KO GMCs. (G and H) Representative WB images of indicated myofibroblast markers in both Ctl and Pdgfra-KO GMCs after treatment with TGFB1 (2 ng/mL) for different times. Protein expression was normalized to GAPDH and expressed as fold change of Ctl GMCs (H). The lanes of gels were run on the same gel but were noncontiguous. Data are presented as mean ± SEM (n = 3). Two-way ANOVA was used for statistical analysis. **P < 0.01 versus Ctl 0 hour; ##P < 0.01 versus corresponding KO group. GMCs, GLI1-positive mesenchymal stem cells; Ctl, control; α-SMA, α-smooth muscle actin.