Acetaminophen impairs ferroptosis in the hippocampus of septic mice by regulating glutathione peroxidase 4 and ferroptosis suppressor protein 1 pathways

by Selleckchem | Nov 05 2023

Background: Neuronal ferroptosis is a major cause of cognitive impairment and mortality in patients with sepsis-associated encephalopathy (SAE). A low dose of acetaminophen (APAP) in septic mice can prevent ferroptosis in the hippocampal tissue; however, the underlying mechanism is unknown. This study aimed to investigate the mechanism by which APAP reduces ferroptosis in the hippocampal tissues of septic mice.

Methods: A mouse model of SAE was established, and the ferroptosis pathway inhibitors RSL3 and iFSP1+RSL3 were used in addition to APAP for the interventions, respectively. The 7-day survival rate of the mice was recorded, and cognitive function was examined using the Morris water maze test. Hematoxylin and eosin staining was performed to observe hippocampal tissue damage. Hippocampal iron and malondialdehyde (MDA) were measured using chemical colorimetric methods. Immunofluorescence was used to detect the reactive oxygen species (ROS) content in hippocampal tissues.

Results: RSL3 reversed the efficacy of APAP on improving cognitive dysfunction in septic mice but did not obviously reverse the survival rate of mice enhanced by APAP. RSL3 aggravated APAP-induced hippocampal tissue damage in mice attenuated by APAP. RSL3 inhibited glutathione peroxidase 4 (GPX4) expression and increased ferroptosis suppressor protein 1 (FSP1) and 4-hydroxy-2-nonenal (4-HNE) expression. RSL3 also reversed the effects of APAP in reducing iron, MDA, and ROS levels in the hippocampal tissues of septic mice. iFSP1+RSL3 further reversed the effect of APAP on ameliorating cognitive dysfunction in septic mice and successfully reversed the survival rate of mice enhanced by APAP. iFSP1+RSL3 aggravated APAP-induced cerebral hippocampal damage. iFSP1+RSL3 inhibited both GPX4 and FSP1, further reversing the effect of APAP on the reduction in iron, 4-HNE, ROS, and MDA levels in the cerebral hippocampus of mice with sepsis.

Conclusion: These data suggest that APAP inhibits ferroptosis in the cerebral hippocampus of septic mice through the GPX4 and FSP1 pathways.

Comments:

The study aimed to investigate the mechanism by which acetaminophen (APAP) reduces ferroptosis in the hippocampal tissues of septic mice, with a focus on sepsis-associated encephalopathy (SAE). Here are the main findings and conclusions of the study:

1. APAP treatment improved cognitive dysfunction in septic mice: The cognitive function of septic mice was assessed using the Morris water maze test. APAP treatment was found to significantly improve cognitive dysfunction in these mice.

2. APAP reduced hippocampal tissue damage: Hematoxylin and eosin staining revealed that APAP treatment attenuated hippocampal tissue damage in septic mice.

3. APAP decreased iron and malondialdehyde (MDA) levels: Chemical colorimetric methods were used to measure hippocampal iron and MDA levels. APAP treatment reduced the levels of iron and MDA in the hippocampal tissues of septic mice.

4. APAP reduced reactive oxygen species (ROS) levels: Immunofluorescence analysis demonstrated that APAP treatment decreased the content of ROS in the hippocampal tissues of septic mice.

5. RSL3, a ferroptosis pathway inhibitor, reversed the effects of APAP: RSL3 treatment reversed the efficacy of APAP in improving cognitive dysfunction in septic mice. It also aggravated APAP-induced hippocampal tissue damage and reversed the reduction in iron, MDA, and ROS levels mediated by APAP.

6. iFSP1+RSL3, another ferroptosis pathway inhibitor, had similar effects to RSL3: iFSP1+RSL3 treatment further reversed the effects of APAP on cognitive dysfunction and survival rate in septic mice. It also aggravated APAP-induced hippocampal tissue damage and reversed the reduction in iron, 4-hydroxy-2-nonenal (4-HNE), ROS, and MDA levels mediated by APAP.

7. GPX4 and FSP1 pathways are involved in APAP's action: RSL3 and iFSP1+RSL3 inhibited glutathione peroxidase 4 (GPX4) expression and increased ferroptosis suppressor protein 1 (FSP1) expression. These findings suggest that APAP inhibits ferroptosis in the cerebral hippocampus of septic mice through the GPX4 and FSP1 pathways.

In conclusion, this study demonstrates that APAP treatment can reduce ferroptosis in the hippocampal tissues of septic mice, leading to improved cognitive function and increased survival rate. The inhibition of ferroptosis appears to be mediated through the GPX4 and FSP1 pathways. These findings contribute to understanding the underlying mechanisms of APAP's neuroprotective effects in sepsis-associated encephalopathy.