The TWEAK/Fn14 pathway is required for calcineurin inhibitor toxicity of the kidneys

Area of Science:

• Nephrology
• Immunology
• Molecular Biology

Background:

• Calcineurin inhibitor toxicity (CNT) commonly affects kidney transplants and native kidneys.
• Cyclosporin A (CsA) and tacrolimus are primary calcineurin inhibitors causing CNT.
• The role of TNF-related weak inducer of apoptosis (TWEAK) in CNT pathogenesis is unclear.

Purpose of the Study:

• To investigate the role of TWEAK in the development of acute calcineurin inhibitor toxicity (CNT).
• To identify the cellular targets and mechanisms underlying CsA-induced nephrotoxicity.

Main Methods:

• Used a mouse model of CsA-induced nephrotoxicity.
• Assessed the impact of TWEAK deficiency on CsA toxicity.
• Investigated the expression of TWEAK receptor Fn14 in kidney cells.
• Examined the effects of recombinant TWEAK (rTWEAK) alone and with CsA in vitro and in vivo.

Main Results:

• TWEAK deficiency significantly reduced CsA-induced tubulotoxicity, inflammatory cytokine expression, and immune cell infiltration.
• Kidney tubular epithelial cells were identified as major CsA targets.
• CsA upregulated Fn14 expression in tubular epithelial cells, sensitizing them to TWEAK.
• Both rTWEAK and CsA induced nephrotoxicity, with synergistic effects when combined.

Conclusions:

• TWEAK is essential for acute calcineurin inhibitor toxicity (CNT) pathogenesis.
• Kidney tubular epithelial cells are key targets of CsA toxicity, with TWEAK exacerbating the damage.
• TWEAK represents a potential therapeutic target for preventing or treating CNT.