NTN1 regulates autophagy through the MAP1B/DAPK1 axis to ameliorate acute kidney injury in vitro

Objectives: Sepsis-associated acute kidney injury (S-AKI) is a common complication, while Netrin 1 (NTN1) is a marker of kidney injury-related diseases. This study thus investigated how NTN1 regulates S-AKI.

Methods: HK-2 cells were exposed to lipopolysaccharides (LPS), where NTN1 expression was manipulated to study the effects of NTN1 on Apoptosis, inflammatory factors (tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6), and Reactive Oxygen Species (ROS) levels. Western blot was conducted to assess the role of NTN1 in microtubule associated protein 1B (MAP1B) phosphorylation and Autophagy marker protein. Cells were treated with NTN1 overexpression and MAP1B phosphorylation inhibitors to determine the connection of NTN1 and MAP1B. The interaction between MAP1B and DAPK1 was investigated by co-immunoprecipitation. Following the successful generation of DAPK1 knockdown and/or overexpressing cell models, ROS and membrane blebbing modifications were subsequently assessed.

Results: Overexpression of NTN1 suppressed HK-2 cell Apoptosis, inflammation, and ROS. MAP1B was an interacting protein of NTN1. NTN1 overexpression increased Atg5 protein expression and light chain 3 (LC3)II/LC3I levels in HK-2 cells, which was reversed by MAP1B phosphorylation inhibitors. MAP1B interacted with DAPK1. DAPK1 knockdown enhanced Apoptosis, ROS, and membrane vesicle inhibition, which was offset by MAP1B overexpression.

Conclusions: NTN1 facilitates cell membrane blebbing to induce Autophagy via regulating MAP1B and DAPK1, thereby alleviating LPS-induced AKI in vitro.