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Updated: Jun 17, 2026
Comparative Proteomic Analysis of Whole Kidney, Medulla, and Cortical Tubules in Diabetic Pathogenesis of Kidney Injury in Mice
Published on: May 2, 2025
Association of immunosuppressant-induced protein changes in the rat kidney with changes in urine metabolite patterns:
Jost Klawitter1, Jelena Klawitter, Erich Kushner
1Department of Anesthesiology, University of Colorado Denver, Aurora, CO 80045, USA. jost.klawitter@ucdenver.edu
Abstract:
The basic mechanisms underlying calcineurin inhibitor (CI) nephrotoxicity and its enhancement by sirolimus are still largely unknown. We investigated the effects of CIs alone and in combination with sirolimus on the renal proteome and correlated these effects with urine metabolite pattern changes. Thirty-six male Wistar rats were assigned to six treatment groups (n = 4/group for proteome analysis and n = 6/group for urine (1)H NMR metabolite pattern analysis): vehicle controls, sirolimus 1 mg/kg/day, cyclosporine 10 mg/kg/day, cyclosporine 10 mg/kg/day + sirolimus 1 mg/kg/day, tacrolimus 1 mg/kg/day, tacrolimus 1 mg/kg/day + sirolimus 1 mg/kg/day. After 28 days, 24 h-urine was collected for (1)H NMR-based metabolic analysis and kidneys were harvested for 2D-gel electrophoresis and histology. Cyclosporine affected the following groups of proteins: calcium homeostasis (regucalcin, calbindin), cytoskeleton (vimentin, caldesmon), response to hypoxia and mitochondrial function (prolyl 4-hydroxylase, proteasome, NADH dehydrogenase), and cell metabolism (kidney aminoacylase, pyruvate dehydrogenase, fructose-1,6-bis phosphate). Several of the changes in protein expression, confirmed by Western blot, were associated with and explained changes in metabolite concentrations in urine. Representative examples are an increase in kidney aminoacylase expression (decrease of hippurate concentrations in urine), up regulation of pyruvate dehydrogenase and fructose-1,6-bisphosphatase, (increased glucose metabolism), and down regulation of arginine/glycine-amidino transferase (most likely due to an increase in creatinine concentrations). Protein changes explained and qualified immunosuppressant-induced metabolite pattern changes in urine.
Insights
This study reveals how calcineurin inhibitors (CIs) and sirolimus impact kidney proteins and urine metabolites. Understanding these drug effects on the renal proteome is key to managing nephrotoxicity.
Area of Science:
- Nephrology
- Proteomics
- Metabolomics
Background:
- Calcineurin inhibitor (CI) nephrotoxicity mechanisms and sirolimus interactions remain unclear.
- Investigating drug-induced changes in renal proteome and urine metabolites is crucial for understanding kidney injury.
Purpose of the Study:
- To investigate the effects of CIs (cyclosporine, tacrolimus) alone and with sirolimus on the rat renal proteome.
- To correlate these proteomic changes with alterations in urine metabolite patterns.
Main Methods:
- Wistar rats received vehicle, sirolimus, cyclosporine, tacrolimus, or combinations for 28 days.
- Kidney proteome analyzed via 2D-gel electrophoresis; urine metabolites analyzed using 1H NMR.
- Western blot confirmed protein expression changes.
Main Results:
- Cyclosporine altered proteins involved in calcium homeostasis, cytoskeleton, hypoxia response, mitochondrial function, and cell metabolism.
- Observed protein expression changes correlated with specific urine metabolite alterations (e.g., kidney aminoacylase and hippurate).
- Drug-induced protein modifications explained observed metabolite pattern shifts in urine.
Conclusions:
- Drug-induced changes in renal protein expression are linked to observable shifts in urine metabolite profiles.
- This study provides insights into the molecular mechanisms of CI nephrotoxicity and sirolimus enhancement.
- Understanding these proteomic and metabolomic interactions can inform strategies for mitigating drug-induced kidney damage.
