Renoprotective effect of esculetin against ischemic acute kidney injury-diabetic comorbidity

Abstract

Mitophagy maintains cellular homeostasis by eliminating damaged mitochondria. Accumulated damaged mitochondria can lead to oxidative stress and cell death. Induction of the PINK1/Parkin-mediated mitophagy is reported to be renoprotective in acute kidney injury (AKI). Esculetin, a naturally available coumarin, has shown protective action against diabetic complications. However, its effect on AKI-diabetes comorbidity has not been explored yet. Therefore, we aimed to investigate the renoprotective effect of esculetin against AKI under diabetic conditions via regulating PINK1/Parkin-mediated mitophagy. For this, type 1 diabetic male Wistar rats were treated with two doses of esculetin (50 and 100 mg/kg/day orally) for five days followed by AKI induction by bilateral ischemic-reperfusion injury (IRI). NRK-52E cells grown in high glucose were exposed to sodium azide (10 mM) for induction of hypoxia/reperfusion injury (HRI) in-vitro. Esculetin (50 µM) treatment for 24 h was given to the cells before HRI. The in-vitro samples were utilized for cell viability and ΔΨm assay, immunoblotting, and immunofluorescence. Rats’ plasma, urine, and kidney samples were collected for biochemical analysis, histopathology, and western blotting. Our results showed a significant decrease in kidney injury-specific markers and increased expression of mitophagy markers (PINK1 and Parkin) with esculetin treatment. Moreover, esculetin prevented the HRI and hyperglycemia-induced decrease in ΔΨm and autophagosome marker. Also, esculetin therapy reduced oxidative stress via increased Nrf2 and Keap1 expression. Esculetin attenuated AKI under diabetic condition by preventing mitochondrial dysfunction via inducing PINK1/Parkin-mediated mitophagy, suggesting its potential as an effective therapy for preventing AKI-diabetes comorbidity.

HIGHLIGHTS

• Impaired mitophagy and increased oxidative stress are major contributors to AKI development.

• Esculetin treatment reduces oxidative stress in AKI-diabetes comorbidity.

• Esculetin activated Nrf2/PINK1/Parkin axis and improved mitophagy.

• Esculetin can be a potential therapy for AKI-diabetes comorbidity prevention and management.

Keywords:

• Esculetin
• mitophagy
• acute kidney injury
• diabetes
• PINK1/parkin pathway

Acknowledgements

ABG sincerely acknowledges the financial support provided by the Birla Institute of Technology and Science, Pilani, Pilani Campus, for carrying out this work.

Ethical approval

The animal experimentation in this study was performed as per the ARRIVE guidelines and approval of the Institutional Animal Ethics Committee [IAEC/RES/31/18].

Authors’ contribution

N.D.: Conceptualization, Writing- original draft preparation, methodology, investigation, data analysis. T.H. and V.S.: Methodology and investigation. H.R.J.: Writing- Review & editing of the manuscript. A.B.G.: Conceptualized and designed the experiments, Writing- Review & editing of the manuscript, Supervision. All authors have approved the final manuscript draft for publication.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All data of this study are included in this manuscript.

Additional information

Funding

The financial support provided by the Birla Institute of Technology and Science, Pilani, Pilani Campus, for carrying out this work.