Abstract: FR-PO166

PKA/CREB Signaling Prevents Adriamycin-Induced Podocyte Apoptosis via Upregulation of Mitochondrial Respiratory Chain Complexes Production

Session Information

  • Mitochondriacs and More
    November 03, 2017 | Location: Hall H, Morial Convention Center
    Abstract Time: 10:00 AM - 10:00 AM

Category: Cell Biology

  • 202 Apoptosis, Proliferation, Autophagy, Cell Senescence, Cell Transformation

Authors

  • Xie, Kewei, Renji Hospital, Shanghai, State..., China
  • Ni, Zhaohui, Renji Hospital, Shanghai, State..., China
  • Gu, Leyi, Renji Hospital, Shanghai, State..., China
Background

The present study was designed to explore the role of cAMP response element binding protein (CREB) in the PKA-induced protection in podocytes.

Methods

Conditionally immortalized differentiated murine podocytes were used in the present experiments. Cell toxicity was examined by using a cell count kit-8. Annexin V/PI staining and flow cytometry were uesd to detect cell apoptosis. MitoSOX™ Red mitochondrial superoxide indicator was used for detecting mitochondrial ROS. We also used Agilent expression profile chip to screen the mRNA expression in differential podocytes treated with or without PKA agonist in the presence or absence ADR. The message RNAs of respiratory chain complexes subunits encoded by mitochondrial genes were detected by using real-time PCR. Luciferase chemiluminescence was used to detect the production of ATP. Western blot was used to detect protein expression.

Results

We found that pretreatment with pCPT-cAMP prevented podocytes against Adriamycin (ADR)-induced increase of cleaved caspase-3 and the loss of podocytes.ADR treatment strikingly enhanced both mitochondrial superoxide and index of ROS in podocyte, this increase was prevented by pCPT-cAMP pre-treatment.Pretreatment with pCPT-cAMP was unable to prevent ADR-induced increase of cleaved caspase 3 expression in CREB RNAi treated podocytes. Data of Agilent expression profile chip studies showed that ADR predominantly decreased the mRNA expression of respiratory chain complex I subunits encoded by mitochondrial genes in podocytes, which was prevented by pretreatment with pCPT-cAMP.Immunoblot experiments showed that activation of PKA prevented ADR-induced decrease of mitochondrial respiratory chain complexes I subunits ND1/3/4 protein expression. Inhibiting of CREB expression prevented pCPT-cAMP-induced ND3, but not ND1/4 protein overproduction in podocytes. CREB RNAi can also block pCPT-cAMP-induced increase of ATP and the expression of Peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1 a).

Conclusion

PKA signaling may upregulate expression of mitochondrial respiratory chain complexes, which reduced ROS production and increased ATP generation, thus prevented ADR-induced podocyte apoptosis. This was at least partially dependent on CREB activation.

Funding

  • Government Support - Non-U.S.