Kidney Week

Abstract: FR-PO165

Spns2 Deficiency Protects the Mouse Kidneys During Ischemia-Reperfusion Injury

Session Information

• AKI: Mechanisms - II
  November 03, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Acute Kidney Injury

• 103 AKI: Mechanisms

Authors

• Cechova, Sylvia, University of Virginia School of Medicine, Charlottesville, Virginia, United States

Sylvia Cechova,

• Yao, Junlan, University of Virginia School of Medicine, Charlottesville, Virginia, United States

Junlan Yao,

• Kharel, Yugesh, University of Virginia School of Medicine, Charlottesville, Virginia, United States

Yugesh Kharel,

• Lynch, Kevin, University of Virginia School of Medicine, Charlottesville, Virginia, United States

Kevin Lynch,

• Okusa, Mark D., University of Virginia School of Medicine, Charlottesville, Virginia, United States

Mark D. Okusa,

Background

Spns2 (Spinster homolog 2) is transmembrane protein that transports sphingosine 1-phosphate, a bioactive lipid that acts as an extracellular ligand and intracellular second messenger in a variety of biological functions. In the present study, we investigated the effect of inducible global Spns2 deletion or pharmacological inhibition of Spns2 in mouse kidneys after bilateral ischemia-reperfusion injury (IRI).

Methods

Ubiquitin-CreERT2;Spns2^fl/fl mice (iSpns2^UBCKO) and iSpns2^fl/fl littermates were injected with tamoxifen (1 mg, i.p.) daily for 5 days and rested for 2 weeks before 28 min ischemia followed by 24 h reperfusion. C57BL/6 mice were pre-treated 24 h before IRI with Spns2 inhibitor (SLF1081851, 10 mg/kg, i.p.) or vehicle. Relative kidney Spns2, Ngal, Kim1, Cxcl1, and Cxcl10 mRNA expression were estimated by qPCR and neutrophil infiltration by immunofluorescence labeling using Ly6G clone1A8 antibody. Kidney injury was evaluated by measuring plasma creatinine (PCr) and BUN and by scoring acute tubular necrosis (ATN) in H&E stained sections.

Results

Relative kidney mRNA of Spns2 in iSpns2^UBCKO mice after tamoxifen treatment was significantly reduced compared to iSpns2^fl/fl mice: 0.5±0.1 vs. 1.0±0.1, P=0.006. After IRI, the increase in mRNA of kidney injury markers Ngal and Kim1 and PCr and BUN in iSpns2^fl/fl mice were significantly reduced in iSpns2^UBCKO mice (4.2±0.7 vs. 1.40±0.2, P=0.0023; 38.8±8.3 vs. 2.4±1.0, P=0.0042; 9±0.1 vs. 0.4±0.1, P=0.0017; and 186.7±13.3 vs. 56.6±11.4, P<0.0001). Cxcl1 and Cxcl10 mRNA and kidney neutrophil infiltration were similar in iSpns2^UBCKO and iSpns2^fl/fl mice after IRI. ATN scores for iSpns2^fl/fl vs. iSpns2^UBCKO were 57.6±3.6 vs.10.1±1.6 (P<0.0001). The increase in PCr and BUN in C57BL/6 mice was reduced significantly by SLF1081851 (1.4±0.3 vs. 0.4± 0.1, P=0.007; 159.7±15.0 vs. 79.9±18.9, P=0.006). SLF1081851 decreased ATN score compared to vehicle (42.8±9.4 vs.14.9±4.3, P=0.027).

Conclusion

Our results demonstrate that genetic global deletion or pharmacological inhibition with a selective Spns2 inhibitor protects kidneys from IRI, suggesting that SPNS2 can serve as a potential target to prevent AKI.

Funding

• NIDDK Support