# Renal allograft interstitial fibrosis: multicellular interactions and therapeutic strategies

**Authors:** Runmin Ding, Qinghuan Shen, Junyi Zhou, Ruoyun Tan, Min Gu, Zijie Wang, Zeping Gui

PMC · DOI: 10.3389/fimmu.2026.1745244 · Frontiers in Immunology · 2026-02-04

## TL;DR

This review explores how different cells contribute to kidney transplant scarring and suggests new ways to treat it.

## Contribution

The paper systematically summarizes multicellular interactions in renal allograft interstitial fibrosis and identifies novel therapeutic targets.

## Key findings

- Renal interstitial fibrosis involves dynamic interactions among immune, epithelial, and stromal cells.
- Key regulatory nodes in profibrotic networks have been identified as potential therapeutic targets.
- Precision interventions could inhibit fibrotic signaling and improve transplant outcomes.

## Abstract

Kidney transplantation remains the most effective treatment for end-stage renal disease (ESRD). However, long-term graft survival is still limited by chronic allograft dysfunction (CAD), which is primarily characterized by renal interstitial fibrosis (RIF). The development of RIF is an actively regulated and progressive process involving both immune and non-immune mechanisms. Within the renal microenvironment, multiple cell populations interact to form a self-reinforcing profibrotic network that ultimately drives irreversible fibrotic remodeling. Despite increasing mechanistic insights, the precise modes of multicellular crosstalk remain incompletely understood, and effective targeted therapies are still lacking in clinical practice. In this review, we systematically summarize the dynamic interactions among immune cells, renal epithelial cells, and stromal cells during renal allograft interstitial fibrosis. By integrating recent advances at the cellular and molecular levels, we identify key regulatory nodes within this multicellular network and discuss emerging therapeutic targets and precision intervention strategies aimed at inhibiting profibrotic signaling, alleviating pathological tissue remodeling, and improving long-term graft function and survival.

## Linked entities

- **Diseases:** end-stage renal disease (MONDO:0004375)

## Full-text entities

- **Genes:** Ms4a1 (membrane-spanning 4-domains, subfamily A, member 1) [NCBI Gene 12482] {aka Cd20, Ly-44, Ms4a2}, Zeb1 (zinc finger E-box binding homeobox 1) [NCBI Gene 21417] {aka 3110032K11Rik, AREB6, BZP, MEB1, Nil2, TCF-8}, Rps6kb1 (ribosomal protein S6 kinase B1) [NCBI Gene 72508] {aka 2610318I15Rik, P70S6K1, S6K, S6K-beta-1, S6K1, p70 S6K-alpha}, F13a1 (coagulation factor XIII, A1 subunit) [NCBI Gene 74145] {aka 1200014I03Rik, F13a}, Stat1 (signal transducer and activator of transcription 1) [NCBI Gene 20846] {aka 2010005J02Rik}, Smad3 (SMAD family member 3) [NCBI Gene 17127] {aka Madh3}, Skil (SKI-like proto-oncogene) [NCBI Gene 20482] {aka Skir, SnoN, sno}, Smurf2 (SMAD specific E3 ubiquitin protein ligase 2) [NCBI Gene 66313] {aka 2810411E22Rik}, Fut8 (fucosyltransferase 8) [NCBI Gene 53618], Upp1 (uridine phosphorylase 1) [NCBI Gene 22271] {aka UPase, UdRPase, Up, Upp}, Tlr4 (toll-like receptor 4) [NCBI Gene 21898] {aka Lps, Ly87, Ran/M1, Rasl2-8}, Atg16l1 (autophagy related 16 like 1) [NCBI Gene 77040] {aka 1500009K01Rik, Apg16l, Atg16l, WDR30}, Dapk2 (death-associated protein kinase 2) [NCBI Gene 13143], Mtor (mechanistic target of rapamycin kinase) [NCBI Gene 56717] {aka 2610315D21Rik, FRAP, FRAP2, Frap1, RAFT1, RAPT1}, Acta2 (actin alpha 2, smooth muscle, aorta) [NCBI Gene 11475] {aka 0610041G09Rik, Actvs, SMAalpha, SMalphaA, a-SMA, alphaSMA}, Icam1 (intercellular adhesion molecule 1) [NCBI Gene 15894] {aka CD54, Icam-1, Ly-47, MALA-2}, Vegfa (vascular endothelial growth factor A) [NCBI Gene 22339] {aka L-VEGF, Vegf, Vpf}, Crtc2 (CREB regulated transcription coactivator 2) [NCBI Gene 74343] {aka 4632407F12Rik, Torc2}, AKT1 (AKT serine/threonine kinase 1) [NCBI Gene 207] {aka AKT, PKB, PKB-ALPHA, PRKBA, RAC, RAC-ALPHA}, Nfkb1 (nuclear factor of kappa light polypeptide gene enhancer in B cells 1, p105) [NCBI Gene 18033] {aka NF-KB1, NF-kappaB, NF-kappaB1, p105, p50, p50/p105}, Stat6 (signal transducer and activator of transcription 6) [NCBI Gene 20852], Hnf4a (hepatic nuclear factor 4, alpha) [NCBI Gene 15378] {aka HNF-4, Hnf4, Hnf4alpha, MODY1, Nr2a1, TCF-14}, Mapk8 (mitogen-activated protein kinase 8) [NCBI Gene 26419] {aka JNK, JNK1, Prkm8, SAPK1}, Sdc1 (syndecan 1) [NCBI Gene 20969] {aka CD138, Sstn, Synd, Synd1, syn-1}, IL10 (interleukin 10) [NCBI Gene 3586] {aka CSIF, GVHDS, IL-10, IL10A, TGIF}, Mir21a (microRNA 21a) [NCBI Gene 387140] {aka Mir21, Mirn21, mmu-mir-21, mmu-mir-21a}, FCGR1A (Fc gamma receptor Ia) [NCBI Gene 2209] {aka CD64, CD64A, FCG1, FCGR1, FCRI, FcgammaRI}, Arpc2 (actin related protein 2/3 complex, subunit 2) [NCBI Gene 76709] {aka 2210023N03Rik, 34kDa, p34-Arc}, Il17a (interleukin 17A) [NCBI Gene 16171] {aka Ctla-8, Ctla8, IL-17, IL-17A, Il17}, Cdh5 (cadherin 5) [NCBI Gene 12562] {aka 7B4, Cd144, VE-Cad, VECD, VEcad, Vec}, Nox4 (NADPH oxidase 4) [NCBI Gene 50490], Acox1 (acyl-Coenzyme A oxidase 1, palmitoyl) [NCBI Gene 11430] {aka AOX, Acox, D130055E20Rik, Paox}, Pdcd1 (programmed cell death 1) [NCBI Gene 18566] {aka Ly101, PD-1, Pdc1}, IL6 (interleukin 6) [NCBI Gene 399500] {aka IL-6}, Pik3r1 (phosphoinositide-3-kinase regulatory subunit 1) [NCBI Gene 18708] {aka PI3K, p50alpha, p55alpha, p85alpha}, Angpt1 (angiopoietin 1) [NCBI Gene 11600] {aka 1110046O21Rik, Ang-1, Ang1}, Ephb2 (Eph receptor B2) [NCBI Gene 13844] {aka Cek5, Drt, ETECK, Erk, Hek5, Nuk}, Nfkbia (nuclear factor of kappa light polypeptide gene enhancer in B cells inhibitor, alpha) [NCBI Gene 18035] {aka Nfkbi}, Mmp9 (matrix metallopeptidase 9) [NCBI Gene 17395] {aka B/MMP9, Clg4b, Gel B, MMP-9, pro-MMP-9}, Ccl21a (C-C motif chemokine ligand 21 (serine)) [NCBI Gene 18829] {aka 6CKBAC2, 6Ckine, ALP, CKb9, Gm1987, SCYA21a}, Nfatc1 (nuclear factor of activated T cells, cytoplasmic, calcineurin dependent 1) [NCBI Gene 18018] {aka 2210017P03Rik, NF-ATc, NFAT2, NFATc, Nfatcb}, Src (src proto-oncogene, non-receptor tyrosine kinase) [NCBI Gene 20779] {aka pp60c-src}, Tnfsf13b (tumor necrosis factor (ligand) superfamily, member 13b) [NCBI Gene 24099] {aka BAFF, BLyS, D8Ertd387e, TALL-1, TALL1, THANK}, Prkca (protein kinase C, alpha) [NCBI Gene 18750] {aka Pkca}, Cd4 (CD4 antigen) [NCBI Gene 12504] {aka L3T4, Ly-4}, Il6 (interleukin 6) [NCBI Gene 16193] {aka Il-6}, Csf1r (colony stimulating factor 1 receptor) [NCBI Gene 12978] {aka CD115, CSF-1R, Csfmr, Fim-2, Fim2, Fms}, Irf9 (interferon regulatory factor 9) [NCBI Gene 16391] {aka Irf-9, Isgf3g, p48}, IL1B (interleukin 1 beta) [NCBI Gene 397122] {aka IL1B1}, Tigit (T cell immunoreceptor with Ig and ITIM domains) [NCBI Gene 100043314] {aka Vstm3}, Smurf1 (SMAD specific E3 ubiquitin protein ligase 1) [NCBI Gene 75788] {aka 4930431E10Rik, mKIAA1625}, BCR (BCR activator of RhoGEF and GTPase) [NCBI Gene 613] {aka ALL, BCR1, CML, D22S11, D22S662, PHL}, Selp (selectin, platelet) [NCBI Gene 20344] {aka CD62P, GMP-140, Grmp, LECAM3, PADGEM}, Vcam1 (vascular cell adhesion molecule 1) [NCBI Gene 22329] {aka CD106, Vcam-1}, SMAD3 (SMAD family member 3) [NCBI Gene 397260] {aka MADH3}, Fap (fibroblast activation protein) [NCBI Gene 14089] {aka SIMP}, Hgf (hepatocyte growth factor) [NCBI Gene 15234] {aka C230052L06Rik, HGF/SF, NK1, NK2, SF, SF/HGF}, TGFB1 (transforming growth factor beta 1) [NCBI Gene 397078] {aka TGF-BETA-1}, Ifng (interferon gamma) [NCBI Gene 15978] {aka IFN-g, If2f, Ifg}, Fn1 (fibronectin 1) [NCBI Gene 14268] {aka E330027I09, Fn, Fn-1}
- **Diseases:** tubular injury (MESH:D000230), renal vascular endothelial dysfunction (MESH:D014652), alloimmune injury (MESH:C536394), failure (MESH:D051437), atrophy (MESH:D001284), chronic kidney injury (MESH:D051436), liver fibrosis (MESH:D008103), metabolic disturbances (MESH:D024821), RIF (MESH:D005355), Inflammatory (MESH:D007249), injury (MESH:D014947), fibrotic diseases (MESH:D004194), mitochondrial dysfunction (MESH:D028361), renal interstitial (MESH:D007984), antibody-mediated injury (MESH:D020274), proteinuria (MESH:D011507), renal fibrogenesis (MESH:D006030), chronic allograft injury (MESH:D020208), RIRI (MESH:D007511), hypoxia (MESH:D000860), damage (MESH:D020263), CAD (MESH:D000092122), hypoxic (MESH:D002534), tubulointerstitial injury (MESH:D009395), AMR (MESH:C565965), acute kidney injury (MESH:D058186), ESRD (MESH:D007676), CKD (MESH:D012080), allograft interstitial (MESH:D065167), cytotoxic (MESH:D064420), MMT (MESH:D055501), endothelial injury (MESH:D057772), IRI (MESH:D015427), microvascular dysfunction (MESH:D017566), RTECs (MESH:D009375), glomerulosclerosis (MESH:D005921), BK virus (MESH:D014777), EndMT (MESH:D008579), UUO (MESH:D014517), necrosis (MESH:D009336), hyperplasia (MESH:D006965), immune dysregulation (OMIM:614878), CTOT-19 (MESH:D000094024), chronic (MESH:D002908), sepsis (MESH:D018805), endothelial (MESH:D005642), Renal allograft interstitial fibrosis (MESH:D007674), copper (MESH:C535468), cardiac and pulmonary fibrosis (MESH:D011658)
- **Chemicals:** lactate (MESH:D019344), 2-DG (MESH:D003847), oxygen (MESH:D010100), bortezomib (MESH:D000069286), galunisertib (MESH:C557799), iron (MESH:D007501), rituximab (MESH:D000069283), fatty acid (MESH:D005227), DCA (MESH:D003999), DAPT (-), Cyclosporine A (MESH:D016572), everolimus (MESH:D000068338), ROS (MESH:D017382), creatinine (MESH:D003404), glucose (MESH:D005947), Lipid (MESH:D008055), LPS (MESH:D008070)
- **Species:** Mus musculus (house mouse, species) [taxon 10090], Rattus norvegicus (brown rat, species) [taxon 10116], Homo sapiens (human, species) [taxon 9606]
- **Cell lines:** TEC — Scophthalmus maximus (Turbot), Spontaneously immortalized cell line (CVCL_J026), C57BL/6J — Mus musculus (Mouse), Transformed cell line (CVCL_C0MW)

## Full text

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## Figures

4 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12913155/full.md

## References

148 references — full list in the complete paper: https://tomesphere.com/paper/PMC12913155/full.md

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Source: https://tomesphere.com/paper/PMC12913155