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Abstract: SA-PO081

Gasdermin D Is Required for Control of Necroptotic Cell Death in AKI

Session Information

  • AKI: Mechanisms - III
    November 05, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
    Abstract Time: 10:00 AM - 12:00 PM

Category: Acute Kidney Injury

  • 103 AKI: Mechanisms

Authors

  • Tonnus, Wulf, Technische Universitat Dresden, Dresden, Sachsen, Germany
  • Maremonti, Francesca, Technische Universitat Dresden, Dresden, Sachsen, Germany
  • Brucker, Anne Marie, Technische Universitat Dresden, Dresden, Sachsen, Germany
  • Linkermann, Andreas, Technische Universitat Dresden, Dresden, Sachsen, Germany

Group or Team Name

  • AG Linkermann
Background

Within the last decade, it has been established that necrotic rather than apoptotic cell death critically mediates acute tubular necrosis in AKI. While the involvement of necroptosis and ferroptosis has been established, the role of pyroptosis, the third major form of necrosis, remains unclear in AKI. This form of regulated necrosis requires proteolytic activation of members of the gasdermin family and is considered highly immunogenic. Thus, we aimed to investigate the role of pyroptosis and its mechanism of action in AKI.

Methods

Immunohistochemistry (IHC) was utilized to detect gasdermin D (GSDMD) in kidney samples of mice after ischemia/reperfusion injury (IRI). Furthermore, gasdermin-deficient mice were investigated in IRI and cisplatin-induced AKI and cisplatin-induced AKI. Mechanistic approaches involved the isolation of renal tubules for studies on cell death propagation and standard biochemistry to detect protein expression kinetics. Finally, MLKL/GSDMDdko mice were generated to investigate the interplay of these caspase-dependent forms of regulated necrosis in AKI.

Results

In GSDMD-IHC of kidney samples after IRI, we detected as specific signal surrounding necrotic tubules. No such signal was detectable within the tubular compartment at any time. Unexpectedly, GSDMDko mice exhibited higher levels of serum creatine and serum urea as well as more severe tubular damage compared to wild type controls. Unlike whole kidney lysates, freshly isolated renal tubules do not express the GSDMD protein. In isolated renal tubules, no changes in kinetics of cell death propagation were detectable upon genetic GSDMD deficiency. In addition, we generated combined necroptosis/pyroptosis-deficient MLKL/GSDMDdko mice. Here, we demonstrate that co-deletion of MLKL rescued the sensitization of GSDMDko mice. Comparable effects were seen in cisplatin-induced AKI.

Conclusion

Our study reveals an unexpected protective role of GSDMD in AKI. Our mechanistic studies indicate the effect of GSDMD to function outside the tubular compartment, specifically surrounding areas of tubular necrosis. This infiltrate appears to limit tubular necroptosis in a non-cell autonomous manner. Alongside with these mechanistic insights, our data urge caution when inhibition of pyroptosis is therapeutically considered.

Funding

  • Private Foundation Support