Kidney Week

Abstract: SA-PO567

The ANLNR431C FSGS Mutation Alters AKT and Rac1 Activation in Podocytes

Session Information

• Noncystic Mendelian Diseases
  November 04, 2017 | Location: Hall H, Morial Convention Center
  Abstract Time: 10:00 AM - 10:00 AM

Category: Genetic Diseases of the Kidney

• 802 Non-Cystic Mendelian Diseases

Authors

• Lane, Brandon M., Duke University School of Medicine, Durham, North Carolina, United States

Brandon M. Lane,

• Hall, Gentzon, Duke University School of Medicine, Durham, North Carolina, United States

Gentzon Hall,

• Spurney, Robert F., Duke University School of Medicine, Durham, North Carolina, United States

Robert F. Spurney,

• Chryst-ladd, Megan, Duke University School of Medicine, Durham, North Carolina, United States

Megan Chryst-ladd,

• Wu, Guanghong, Duke University School of Medicine, Durham, North Carolina, United States

Guanghong Wu,

• Gbadegesin, Rasheed A., Duke University School of Medicine, Durham, North Carolina, United States

Rasheed A. Gbadegesin,

Background

We previously reported that a heterozygous missense mutation (R431C) in ANLN caused focal and segmental glomerulosclerosis (FSGS) in a kindred with familial FSGS. Anillin has been shown to play a significant role in the regulation of cell motility and survival signaling through the phosphoinositide 3-kinase (PI-3K)/AKT pathway. We hypothesized that the ANLN R431C mutation may exert its pathogenic effects in FSGS by inducing aberrant PI3K/AKT pathway signaling.

Methods

Immortalized human podocyte cell lines were stably transfected with tGFP vector control, tGFP-tagged WT (ANLNWT) or mutant (ANLNR431C) constructs using a lentiviral gene delivery system. We examined the effect of the R431C mutation on cell migration, cell proliferation and apoptosis. Pharmacologic inhibitors were used to determine the role of PI3K/AKT signaling pathways in the observed podocyte phenotypes.

Results

Overexpression of ANLN_R431C increased cell migration (p=0.002), proliferation (p=0.003), and apoptosis (p=0.0015) compared to cells overexpressing equivalent levels of ANLN_WT. Western blot analyses and Rac1 activity pulldown assays showed an increase in AKT and Rac1 activation in the ANLN_R431C-overexpressing podocytes relative to ANLN_WT-overexpressing podocytes. The increase in podocyte motility was attenuated by the mTor inhibitor rapamycin and the selective Rac1 inhibitor NSC-23766.

Conclusion

The ANLN_R431C mutation causes dysregulation of podocyte motility and survival signaling through enhanced activation of PI3K/AKT and Rac1. Targeting PI3K/AKT and Rac1 signaling may have a role in the treatment of FSGS.

Funding

• NIDDK Support