Genetic Knockout of Fatty Acid Amide Hydrolase Ameliorates Cisplatin-Induced Nephropathy in Mice

PARVB deficiency alleviates cisplatin-induced tubular injury by inhibiting TAK1 signaling

Cisplatin-induced renal tubular injury largely restricts the wide-spread usage of cisplatin in the treatment of malignancies. Identifying the key signaling pathways that regulate cisplatin-induced renal tubular injury is thus clinically important. PARVB, a focal adhesion protein, plays a crucial role in tumorigenesis. However, the function of PARVB in kidney disease is largely unknown. To investigate whether and how PARVB contributes to cisplatin-induced renal tubular injury, a mouse model (PARVB cKO) was generated in which PARVB gene was specifically deleted from proximal tubular epithelial cells using the Cre-LoxP system. In this study, we found depletion of PARVB in proximal tubular epithelial cells significantly attenuates cisplatin-induced renal tubular injury, including tubular cell death and inflammation. Mechanistically, PARVB associates with transforming growth factor-β-activated kinase 1 (TAK1), a central regulator of cell survival and inflammation that is critically involved in mediating cisplatin-induced renal tubular injury. Depletion of PARVB promotes cisplatin-induced TAK1 degradation, inhibits TAK1 downstream signaling, and ultimately alleviates cisplatin-induced tubular cell damage. Restoration of PARVB or TAK1 in PARVB-deficient cells aggravates cisplatin-induced tubular cell injury. Finally, we demonstrated that PARVB regulates TAK1 protein expression through an E3 ligase ITCH-dependent pathway. PARVB prevents ITCH association with TAK1 to block its ubiquitination. Our study reveals that PARVB deficiency protects against cisplatin-induced tubular injury through regulation of TAK1 signaling and indicates targeting this pathway may provide a novel therapeutic strategy to alleviate cisplatin-induced kidney damage.

Pre-treatment with β-hydroxybutyrate mitigates cisplatin-induced acute kidney injury

β-Hydroxybutyrate (β-HB), the primary circulating ketone body, plays a dual role as both a metabolic fuel and an endogenous signaling molecule, offering diverse systemic benefits. Recent studies have highlighted the renoprotective effects of exogenous β-HB therapy in various animal models of kidney disease. In this investigation, our goal was to assess whether pre-treatment with exogenous β-HB could alleviate kidney damage in a mouse model of cisplatin-induced acute kidney injury (AKI). Prior to cisplatin administration, intraperitoneal administration of β-HB was carried out, and the groups were classified into four: Sham, β-HB, cisplatin, and β-HB + cisplatin. The tubular damage score and serum creatinine levels were significantly lower in the β-HB + cisplatin group compared to the cisplatin group. Furthermore, the expression of phosphorylated NF-κB, inflammatory cytokines, and the quantity of F4/80-positive macrophages in the β-HB + cisplatin group were reduced compared to those in the cisplatin group. Additionally, oxidative stress markers for DNA, protein, and lipid in the β-HB + cisplatin group were markedly diminished compared to those in the cisplatin group. The number of TUNEL-positive and cleaved caspase 3-positive tubular cells in the β-HB + cisplatin group was lower than in the cisplatin group. Pre-treating with exogenous β-HB effectively mitigated kidney damage by suppressing inflammation, oxidative stress, and tubular apoptosis in cisplatin-induced AKI. Therefore, exogenous β-HB as a pre-treatment emerges as a promising and novel strategy for preventing cisplatin-induced AKI.