Senolytics, dasatanib plus quercetin, reduce kidney inflammation, senescent cell abundance, and injury while restoring geroprotective factors in murine diabetic kidney disease.

D+Q treatment improved kidney function in streptozotocin-induced diabetic mice without altering glucose levels.

• Diabetes mellitus was induced with intraperitoneal streptozotocin in male C57BL/6J mice.
• Treatment consisted of a 5-day oral gavage regimen of dasatinib plus quercetin (5 and 50 mg/kg, respectively) or vehicle.
• Kidney function improvements were observed versus diabetic controls.
• Glucose levels were not altered by D+Q treatment, indicating the renal benefits were independent of glycemic control.

D+Q reduced markers of kidney injury including glomerular and tubular injury markers in diabetic mice.

• Both glomerular and tubular markers of kidney injury were reduced with D+Q treatment compared to diabetic controls.
• Fibrosis markers were also reduced following D+Q treatment.
• The treatment regimen was a single 5-day 'hit-and-run' oral gavage course.
• Reductions in injury markers occurred in the context of persistent hyperglycemia, suggesting direct kidney-protective effects.

D+Q reduced cellular senescence marker p16Ink4a and senescence-associated inflammation in diabetic kidneys.

• Senescent cell abundance, as measured by p16Ink4a expression, was reduced in D+Q-treated diabetic mice versus diabetic controls.
• Senescence-associated inflammation was reduced alongside macrophage-associated inflammation.
• Macrophage infiltration was reduced in the kidney following D+Q treatment.
• These findings are consistent with the known senolytic mechanism of selectively removing senescent cells.

D+Q treatment increased geroprotective factors α-Klotho and Sirtuin-1 in diabetic kidneys.

• α-Klotho levels increased in D+Q-treated mice compared to diabetic controls.
• Sirtuin-1 levels also increased following D+Q treatment.
• Both α-Klotho and Sirtuin-1 are recognized geroprotective factors associated with kidney health and aging.
• Restoration of these factors represents a novel finding of senolytic treatment in diabetic kidney disease.

D+Q reduced high glucose-induced senescence and NF-κB-mediated inflammation in human renal tubular epithelial cells (HK2) in vitro.

• HK2 cells were treated with high glucose conditions to model diabetic kidney injury in vitro.
• D+Q treatment reduced senescence markers in high glucose-treated HK2 cells.
• NF-κB inflammatory signaling was reduced in HK2 cells following D+Q treatment.
• These in vitro findings support a direct cellular mechanism for D+Q's reparative effects on renal tubular epithelial cells.

D+Q reduced high glucose-induced senescence and inflammation in human endothelial cells (HUVECs) in vitro.

• HUVECs were exposed to high glucose conditions and then treated with D+Q.
• D+Q reduced senescence and NF-κB inflammation in high glucose-treated HUVECs.
• These findings suggest D+Q has protective effects on the renal endothelium relevant to diabetic kidney disease.
• The in vitro endothelial cell results complement the in vivo murine findings.

D+Q reduced high glucose-induced senescence and inflammation in U937-derived macrophages in vitro.

• U937 cells differentiated into macrophages were treated with high glucose and then exposed to D+Q.
• D+Q reduced senescence and NF-κB-mediated inflammation in high glucose-treated macrophages.
• This finding aligns with in vivo observations of reduced macrophage-associated inflammation in diabetic kidneys.
• The macrophage data support a role for D+Q in modulating the kidney inflammatory landscape through effects on immune cells.

Prior pilot clinical trial data showed that D+Q reduced systemic inflammation, senescent cell abundance, and macrophage infiltration in fat in patients with DKD.

• The prior pilot clinical trial in patients with DKD was referenced as supporting context for the current murine study.
• D+Q reduced systemic inflammation in DKD patients in the clinical trial.
• Senescent cell abundance and macrophage infiltration in fat were reduced in DKD patients treated with D+Q.
• The current murine study was conducted to establish D+Q senotherapeutic effects specifically on diabetic kidney injury, senescence, inflammation, and geroprotective factors not examined in the clinical trial.