Y-box protein 1 mediates PDGF-B effects in mesangioproliferative glomerular disease

Area of Science:

• Nephrology
• Molecular Biology
• Cell Signaling

Background:

• Platelet-derived growth factor-B (PDGF-B) is crucial in mesangioproliferative glomerular diseases.
• The downstream targets and precise role of PDGF-B signaling in these conditions require further elucidation.

Purpose of the Study:

• To identify downstream signaling targets of PDGF-B in mesangioproliferative glomerular disease.
• To investigate the role of Y-box protein-1 (YB-1) in PDGF-B-mediated kidney pathology.

Main Methods:

• Utilized anti-Thy1.1-induced mesangioproliferative glomerulonephritis and other experimental kidney disease models.
• Assessed YB-1 localization and expression in kidney cells.
• Investigated the involvement of PDGF-B signaling and the mitogen-activated protein kinase (MAPK) pathway using PDGF aptamers and U0126 inhibitor.
• Performed in vitro studies and RNA interference (RNAi) to assess YB-1 function.

Main Results:

• YB-1 was identified as a downstream target of PDGF-B.
• In mesangioproliferative glomerulonephritis, YB-1 translocated from the nucleus to the cytoplasm and its expression was upregulated.
• This YB-1 relocalization and upregulation were dependent on PDGF-B signaling via the MAPK pathway.
• YB-1 knockdown abolished the mitogenic effects of PDGF-B in vitro.
• YB-1 nuclear-to-cytoplasmic translocation and upregulation were absent in models without significant mesangial cell proliferation.

Conclusions:

• YB-1 is a specific and necessary downstream target of PDGF-B in mesangioproliferative glomerular disease.
• PDGF-B signaling, through the MAPK pathway, induces YB-1 expression and cytoplasmic translocation, contributing to mesangial cell proliferation.
• YB-1 plays a critical role in the pathogenesis of PDGF-B-driven kidney diseases.