Trimethylamine N-oxide Induced Chronic Kidney Injury by Triggering PANoptosis

Area of Science:

• Biochemistry
• Nephrology
• Cellular Biology

Background:

• Trimethylamine N-oxide (TMAO) is linked to kidney disease progression.
• The precise mechanisms of TMAO-induced kidney injury remain largely unknown.
• Regulated cell death pathways are implicated in various organ injuries.

Purpose of the Study:

• To investigate the role of regulated cell death in trimethylamine N-oxide (TMAO)-induced chronic kidney injury.
• To elucidate the specific cell death pathways activated by TMAO in the kidneys.

Main Methods:

• A mouse model of chronic kidney injury was established via daily intraperitoneal injection of TMAO for three months.
• Kidney function was assessed by measuring plasma creatinine and blood urea nitrogen levels.
• Kidney pathology, fibrosis, and the expression of key proteins involved in apoptosis, necroptosis, pyroptosis, and iron metabolism were analyzed using Masson staining and Western blotting.

Main Results:

• TMAO administration significantly elevated plasma creatinine and blood urea nitrogen levels, indicating impaired kidney function.
• Histological analysis revealed increased kidney fibrosis in the TMAO-treated group.
• Western blot analysis demonstrated significantly upregulated expression of proteins associated with PANoptosis (caspase-8, NLRP3, IL-1beta, GSDMD, ZBP1, RIP3, MLKL) and iron homeostasis (TFR1, FTH, FPN, NRF2, GPX4), without changes in iron or MDA levels.

Conclusions:

• PANoptosis, encompassing pyroptosis, apoptosis, and necroptosis, is a key mechanism contributing to TMAO-induced chronic kidney injury.
• TMAO-induced kidney damage involves complex cellular death pathways and alterations in iron metabolism regulators.
• These findings provide novel insights into the pathogenesis of TMAO-related nephropathy and suggest potential therapeutic targets.