ASK1 Inhibitor Halts Progression of Diabetic Nephropathy in Nos3-Deficient Mice

Area of Science:

• Nephrology
• Molecular Biology
• Pharmacology

Background:

• Diabetic kidney disease (DKD) is a major complication of diabetes, characterized by inflammation and fibrosis.
• p38 mitogen-activated protein kinase (MAPK) signaling contributes to DKD pathogenesis.
• Apoptosis signal-regulating kinase 1 (ASK1) is an upstream activator of p38 MAPK, implicated in inflammation and oxidative stress.

Purpose of the Study:

• To investigate the therapeutic potential of a selective ASK1 inhibitor (GS-444217) in preventing and treating diabetic nephropathy in a mouse model.
• To determine if ASK1 inhibition impacts p38 MAPK activation, hypertension, and renal injury in diabetic mice.

Main Methods:

• Diabetes was induced in hypertensive endothelial nitric oxide synthase (Nos3)-deficient mice using streptozotocin (STZ).
• Diabetic mice received either early (2-8 weeks post-STZ) or late (8-15 weeks post-STZ) intervention with the ASK1 inhibitor GS-444217 via chow.
• Renal function, glomerulosclerosis, albuminuria, p38 MAPK activation, and renal inflammation were assessed.

Main Results:

• GS-444217 treatment abrogated p38 MAPK activation in diabetic kidneys but did not affect hypertension.
• Early intervention significantly inhibited glomerulosclerosis and reduced renal dysfunction, but not albuminuria.
• Late intervention improved renal function and halted glomerulosclerosis, renal inflammation, and tubular injury, without affecting established albuminuria.

Conclusions:

• ASK1 is a viable therapeutic target for mitigating diabetic nephropathy.
• ASK1 inhibition can reduce renal inflammation and fibrosis in DKD, independent of blood pressure control.
• Therapeutic strategies targeting ASK1 may offer benefits for patients with diabetic kidney disease.