Absence of ULK1 decreases AMPK activity in the kidney, leading to chronic kidney disease progression

Area of Science:

• Nephrology
• Molecular Biology
• Biochemistry

Background:

• AMP-activated protein kinase (AMPK) inactivation in chronic kidney disease (CKD) deteriorates kidney energy status, creating a cycle of disease exacerbation.
• Unc-51-like kinase 1 (ULK1) is a downstream target of AMPK, but recent findings suggest ULK1 may also regulate AMPK activity.

Purpose of the Study:

• To investigate the role of ULK1 in the mechanisms underlying chronic kidney disease (CKD) exacerbation.
• To determine if ULK1 deficiency exacerbates kidney dysfunction and fibrosis in a CKD model.

Main Methods:

• Utilized ULK1 knockout (Ulk1-/-) mice to establish a chronic kidney disease (CKD) model.
• Assessed renal function, renal fibrosis, AMPK activity, and cellular energy status (AMP/ATP ratio) in control and CKD mice with and without ULK1.

Main Results:

• CKD models lacking ULK1 (Ulk1-/-) showed significantly worsened renal function and fibrosis compared to controls.
• ULK1 deficiency led to reduced AMPK activity and impaired β-oxidation in the kidneys, resulting in an energy deficit (increased AMP/ATP ratio).
• Even in non-CKD conditions, ULK1 deficiency suppressed kidney AMPK activity.

Conclusions:

• ULK1 plays a crucial role in maintaining kidney energy status and AMPK activity.
• ULK1 deficiency exacerbates kidney injury and fibrosis in CKD.
• ULK1 represents a novel therapeutic target for managing chronic kidney disease by regulating kidney AMPK activity.