Investigations into ferroptosis in methylmercury-induced acute kidney injury in mice

Environ Toxicol. 2023 Jun;38(6):1372-1383. doi: 10.1002/tox.23770. Epub 2023 Mar 7.

Abstract

Methylmercury (MeHg) is a highly poisonous form of mercury and a risk factor for kidney impairment in humans that currently has no effective means of therapy. Ferroptosis is a non-apoptotic metabolic cell death linked to numerous diseases. It is currently unknown whether ferroptosis takes part in MeHg-induced kidney damage. Here, we established a model of acute kidney injury (AKI) in mice by gavage with different doses of MeHg (0, 40, 80, 160 μmol/kg). Serological analysis revealed elevated levels of UA, UREA, and CREA; H&E staining showed variable degrees of renal tubule injury; qRT-PCR detection displayed increased expression of KIM-1 and NGAL in the groups with MeHg treatment, indicated that MeHg successfully induced AKI. Furthermore, MDA levels enhanced in renal tissues of mice with MeHg exposure whereas GSH levels decreased; ACSL4 and PTGS2 nucleic acid levels elevated while SLC7A11 levels reduced; transmission electron microscopy illustrated that the density of the mitochondrial membrane thickened and the ridge reduced considerably; protein levels for 4HNE and TfR1 improved since GPX4 levels declined, all these results implying the involvement of ferroptosis as a result of MeHg exposure. Additionally, the observed elevation in the protein levels of NLRP3, p-p65, p-p38, p-ERK1/2, and KEAP1 in tandem with downregulated Nrf2 expression levels indicate the involvement of the NF-κB/NLRP3/MAPK/Nrf2 pathways. All the above findings suggested that ferroptosis and the NF-κB/NLRP3/MAPK/Nrf2 pathways are implicated in MeHg-induced AKI, thereby providing a theoretical foundation and reference for future investigations into the prevention and treatment of MeHg-induced kidney injury.

Keywords: acute kidney injury; ferroptosis; methylmercury; pathways.

MeSH terms

  • Acute Kidney Injury* / chemically induced
  • Acute Kidney Injury* / metabolism
  • Animals
  • Ferroptosis*
  • Humans
  • Kelch-Like ECH-Associated Protein 1 / metabolism
  • Methylmercury Compounds* / toxicity
  • Mice
  • NF-E2-Related Factor 2 / metabolism
  • NF-kappa B / metabolism
  • NLR Family, Pyrin Domain-Containing 3 Protein / metabolism

Substances

  • Methylmercury Compounds
  • Kelch-Like ECH-Associated Protein 1
  • NF-kappa B
  • NF-E2-Related Factor 2
  • NLR Family, Pyrin Domain-Containing 3 Protein