Kidney Week

Abstract: SA-PO642

Inhibition of Platelet-Derived Growth Factor-Induced Signaling and Filopodia Formation in Cultured Human Mesangial Cells by Sheng Ping, a Chinese Herbal Medicine

Session Information

• Glomerular Diseases: IgA and Complement-Mediated GN
  November 05, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1302 Glomerular Diseases: Immunology and Inflammation

Authors

• Huang, Zhi qiang, The University of Alabama at Birmingham, Birmingham, Alabama, United States

Zhi qiang Huang,

• Novak, Lea, The University of Alabama at Birmingham, Birmingham, Alabama, United States

Lea Novak,

• Zhang, Xianwen, Long Hua Hospital, Shanghai, Shanghai, China

Xianwen Zhang,

• Hall, Stacy D., The University of Alabama at Birmingham, Birmingham, Alabama, United States

Stacy D. Hall,

• Wang, Lin, Long Hua Hospital, Shanghai, Shanghai, China

Lin Wang,

• Chen, Yiping, Long Hua Hospital, Shanghai, Shanghai, China

Yiping Chen,

• Julian, Bruce A., The University of Alabama at Birmingham, Birmingham, Alabama, United States

Bruce A. Julian,

• Novak, Jan, The University of Alabama at Birmingham, Birmingham, Alabama, United States

Jan Novak,

Background

Proliferation of mesangial cells is commonly observed in kidney-biopsy specimens of patients with IgA nephropathy (IgAN). This process is thought to involve several factors, such as platelet-derived growth factor (PDGF) with its corresponding receptors and downstream protein kinases, including a focal-adhesion kinase (FAK) involved in the control of cell migration. Histologically, PDGF induces formation of filopodia, slender cytoplasmic projections, in cultured mesangial cells. Here we assessed the effects of Sheng Ping, a traditional Chinese herbal medicine, on PDGF-induced signaling and filopodia formation in cultured primary human mesangial cells.

Methods

Quiescent primary human mesangial cells were activated with PDGF (10 ng/ml) for 15 min at 37^oC. Sheng Ping, an inhibitor of FAK (PF 573288), or medium only were added to mesangial cells prior to PDGF addition. Negative control consisted of mesangial cells with medium only. After the incubation with PDGF, cells were washed, and cell lysates were analyzed by SDS-PAGE immunoblotting using antibodies specific for protein kinases and their phosphorylated variants. For imaging analyses, mesangial cells were cultured on 4-chamber glass slides and treated as described above. Then, the cells were washed, fixed, permeabilized, and stained with TRITC-phalloidin (specific for fibrillar actin) and a nuclear stain. To assess formation of filopodia, the stained cells were examined by a fluorescence microscope using 60x objective.

Results

Sheng Ping inhibited PDGF-induced formation of filopodia in the cultured mesangial cells, phosphorylation of FAK, extracellular signal-regulated kinase ½ (ERK1/2), and a serine/threonine kinase 1 (AKT1). PF 573288, a positive control for FAK inhibition, inhibited filopodia formation as well as phosphorylation of FAK, ERK1/2, and AKT1.

Conclusion

Sheng Ping, Chinese herbal medicine, blocked PDGF-induced formation of filopodia and phosphorylation of several proteins in cultured human mesangial cells. The clinical benefit of Sheng Ping for treatment of patients with IgA nephropathy may, in part, be based on its effect to inhibit the signaling pathways in mesangial cells activated by PDGF.

Funding

• NIDDK Support