AIM: We investigated whether preconditioning with caloric restriction (CR) ameliorates kidney ischaemia/reperfusion (I/R) injury and whether the salutary effects of CR are mediated through enhanced autophagy and/or activation of key metabolic sensors SIRT1, AMP-kinase and PGC-1α. METHODS: Six- to seven-week-old Wistar rats were divided into three groups: (i) sham-operated group; (ii) I/R group (40-min ischaemia followed by 24 h of reperfusion); and (iii) I/R group kept under CR (energy intake 70%) for 2 weeks before surgery. In additional experiments, sirtinol and 3-methyladenine (3-MA) were used as inhibitors of SIRT1 and autophagy respectively. Renal function was measured, and acute tubular damage and nitrotyrosine expression were scored. Kidney adenosine monophosphate-activated kinase (AMPK), SIRT1, eNOS, PGC-1α and LC-3B expressions were measured. RESULTS: Caloric restriction improved renal function, protected against the development of acute tubular necrosis and attenuated I/R-induced nitrosative stress. Kidney I/R injury decreased eNOS and PGC-1α expression, inhibit autophagy and increased SIRT1 and AMPK expressions by 2.6- and fourfold respectively. However, phosphorylation level of AMPK was decreased. As compared with I/R injury group, CR further increased kidney SIRT1 expression by 1.8-fold, promoted autophagy and counteracted I/R-induced decreases in the expression of eNOS and PGC-1α. 3-MA abolished the renoprotective effects of CR, whereas sirtinol did not influence renal function in CR rats with I/R injury. CONCLUSIONS: Caloric restriction ameliorates acute kidney I/R injury through enhanced autophagy and counteraction of I/R-induced decreases in the renal expression of eNOS and PGC-1α.
AIM: We investigated whether preconditioning with caloric restriction (CR) ameliorates kidney ischaemia/reperfusion (I/R) injury and whether the salutary effects of CR are mediated through enhanced autophagy and/or activation of key metabolic sensors SIRT1, AMP-kinase and PGC-1α. METHODS: Six- to seven-week-old Wistar rats were divided into three groups: (i) sham-operated group; (ii) I/R group (40-min ischaemia followed by 24 h of reperfusion); and (iii) I/R group kept under CR (energy intake 70%) for 2 weeks before surgery. In additional experiments, sirtinol and 3-methyladenine (3-MA) were used as inhibitors of SIRT1 and autophagy respectively. Renal function was measured, and acute tubular damage and nitrotyrosine expression were scored. Kidney adenosine monophosphate-activated kinase (AMPK), SIRT1, eNOS, PGC-1α and LC-3B expressions were measured. RESULTS: Caloric restriction improved renal function, protected against the development of acute tubular necrosis and attenuated I/R-induced nitrosative stress. Kidney I/R injury decreased eNOS and PGC-1α expression, inhibit autophagy and increased SIRT1 and AMPK expressions by 2.6- and fourfold respectively. However, phosphorylation level of AMPK was decreased. As compared with I/R injury group, CR further increased kidney SIRT1 expression by 1.8-fold, promoted autophagy and counteracted I/R-induced decreases in the expression of eNOS and PGC-1α. 3-MA abolished the renoprotective effects of CR, whereas sirtinol did not influence renal function in CR rats with I/R injury. CONCLUSIONS: Caloric restriction ameliorates acute kidney I/R injury through enhanced autophagy and counteraction of I/R-induced decreases in the renal expression of eNOS and PGC-1α.
Authors: Marc Johnsen; Torsten Kubacki; Assa Yeroslaviz; Martin Richard Späth; Jannis Mörsdorf; Heike Göbel; Katrin Bohl; Michael Ignarski; Caroline Meharg; Bianca Habermann; Janine Altmüller; Andreas Beyer; Thomas Benzing; Bernhard Schermer; Volker Burst; Roman-Ulrich Müller Journal: J Am Soc Nephrol Date: 2020-02-28 Impact factor: 10.121