Related Experiment Video
Updated: Oct 28, 2026
Measurement of Tissue Non-Heme Iron Content using a Bathophenanthroline-Based Colorimetric Assay
Published on: January 31, 2022
Ferro-Immuno-Structural Axis (FISA): Kidney specific microplastic toxicity via TLR18 centric immunosuppression and
Zhihao Ren1, Yaxuan Zhou1, Shuxia Zhao1
1School of Bioengineering and Technology, Tianshui Normal University, Gansu Province, PR China.
Abstract:
Toll-like receptors (TLRs) are central to innate immunity, yet the expanded TLR repertoire in teleost fish and its tissue-specific response to microplastic (MP) stress remain poorly understood. We performed an integrated genome-wide analysis of the TLR family in rainbow trout (Oncorhynchus mykiss) and conducted multi-tissue transcriptomic profiling (kidney, intestine, liver, muscle, brain, and gill) following MP exposure (500 μg/L). The rainbow trout genome contains 21 TLR members, including six TLR13 paralogs and fish-specific TLR18. Multi-tissue transcriptomics revealed kidney-specific TLR18 centric immunosuppression: TLR18 was exclusively and dramatically downregulated (log2FC = -2.90, P = 1.22 × 10-11), accompanied by suppression of TLR8, TLR13, TLR21, and TLR3. The trafficking regulator unc93b1 (-2.69, P = 1.66 × 10-8) and downstream nodes IRF2, JAK1, TRAF2, and RELA/p65 were all significantly inhibited, indicating pathway-level silencing. Notably, fth1a exhibited extreme kidney-specific upregulation (log2FC = 16.99, P = 5.18 × 10-25) but downregulation in other tissues, revealing ferroptosis-like iron dyshomeostasis. Heat shock proteins collapsed comprehensively (6/6 members, P < 0.05), coupled with glomerular filtration barrier damage (col4a1/6, nphs2, wt1). These correlational data support a hypothetical Ferro-Immuno-Structural Axis (FISA) model that may integrate kidney specific microplastic toxicity through TLR18 centric immunosuppression, iron dyshomeostasis, and structural disintegration.
