henhaobio
Sign in

Science Translational MedicineCell BiologyPeer-reviewed journal article

HIF1α gates tendon response to overload and drives tendinopathy independently of vascular recruitment

Greta MoschiniiD, Archana G. MohananiD, Izabella S. NiewczasiD, Diane E. TayloriD, Patrick Klaus JaegeriD, Guillermo TurieliD, Amro A. HussieniD, Stefania L. WunderliiD, Olivia Baumberger, Maja WollebiD, Florence MartiiD, Barbara P. Niederöst, Maja Bollhalder, Raphaela ArdicogluiD, Nathalie TischiD, Evi MasscheleiniD, Shauni LoopmansiD, Sarah MoriceiD, Santiago ArdilesiD, Lieke MousiD, Bart GhesquièreiD, Matthew R. AronoffiD, Monika HilbeiD, Farah SelmaniD, Karl WieseriD, , Jess Gerrit SnedekeriD

PDFDOIPreprint

In-depth summary

Claude Opus 5.5 · xhigh effort · 5 Nov 2026 · from the full text of version 1 (3 Feb 2025)

Mechanical overload activates hypoxia-inducible factor 1-alpha (HIF1a) in tenocytes to drive tendinopathy independently of VEGFA-mediated vascular ingrowth, and tenocyte Hif1a deletion prevents overload-induced tendon degeneration in mice.

Whether pathological blood vessel ingrowth drives tendinopathy or merely accompanies failed healing after mechanical overload has remained a central debate, and the upstream role of hypoxia-inducible factor 1-alpha (HIF1a) was unclear. Genetic decoupling in mice proves that tenocyte HIF1a activation drives matrix derangement independently of vascularization and acts as a targetable checkpoint during overload.

Key results

  1. ShownDiseased human proximal long head biceps tendons exhibit extracellular matrix remodeling, 3-fold elevated mature collagen crosslinks, and activated HIF1a hypoxia signaling.

    Proximal LHBT showed higher Bonar scores than distal LHBT (p=0.0068, n=28) and gracilis tendons (p<0.0001, n=17), lower COL1A1/COL2A1 with elevated COL3A1/COL5 (p<0.0001, n=26), 3-fold higher mature PYD and DPD crosslinks, 1492 DEGs (641 up, 851 down; padj<0.05, |log2FC|>1, n=15) enriched for hypoxia/glycolysis/HIF1a targets, and nuclear HIF1a staining. · Diseased human tendons show substantially…; Hypoxia signaling is activated in human…; Figure legends

  2. ShownTenocyte-specific Vhl deletion in mice stabilizes HIF1a and suffices to trigger human-like tendinopathy, matrix crosslink accumulation, and impaired tendon mechanics.

    Scx^Cre;Vhl^(f/f) tendons exhibited rounded tenocytes, elevated Col3a1/Col1a1 and PYD/DHLNL crosslinks, a 33% reduction in elastic modulus (n=5), a 30% decrease in stress-relaxation decay (n=3), and dense core CD31+ vessels (n=10 vs 6 WT) and NF-M+ nerves (n=7 vs 6 WT); co-deleting Hif1a rescued all pathological features except hypercellularity. · Activation of HIF1α in tendon cells is…; Figure legends

  3. ShownVEGFA drives vascular and neural ingrowth into Vhl-deficient tendons, but blocking vascular recruitment does not rescue matrix or mechanical pathology.

    Vhl-KO tenocytes secreted >4-fold higher VEGFA than WT, and deleting one Vegfa allele in Scx^Cre;Vhl^(f/f);Vegfa^(+/f) mice prevented CD31+ vessel (n=7) and NF-M+ nerve (n=5) infiltration into the Achilles core, but failed to restore cell roundness, COL3A1/COL5A1/COL5A2 (n=5), crosslinks (n=6), elastic modulus (n=4), or viscoelasticity (n=3). · VEGFA-mediated vascular recruitment drives…; Figure legends

  4. ShownMechanical overload above the calcium-signaling strain threshold activates nuclear HIF1a in human tenocytes, and tenocyte Hif1a deletion prevents overload tendinopathy.

    Stretching human tenocytes above the Ca2+ threshold (n=9 donors) induced nuclear HIF1a activity peaking at 4 h and VEGFA secretion at 72 h (n=6); after 12-week synergist ablation overload in mice, WT plantaris tendons developed cell rounding, immature collagen fibers, 2-fold higher PYD crosslinks, 19% lower stiffness, and 22% higher failure strain, all rescued in Scx^Cre;Hif1a^(f/f) mice. · Mechanical overload induces HIF1α activation; HIF1α inhibition rescues overload- induced…; Figure legends

Methods, data and reproducibility

Human diseased biceps, rotator cuff tear, and healthy gracilis tendons were profiled by histopathology, bulk RNA-seq, label-free LC-MS/MS proteomics, and collagen crosslink mass spectrometry. Tenocyte-targeted mouse knockouts (Scx^Cre with Vhl, Hif1a, and/or Vegfa), uniaxial mechanical testing, 3D neurovascular imaging, human tenocyte stretching, and murine synergist ablation tested causality.

  • Human diseased long head biceps tendons (proximal vs distal LHBT), rotator cuff tear tendons, and gracilis controls · human · n = 28 LHBT (n=15 RNA-seq; n=26 MS), 4 RCTT, 17 gracilis controls
  • Tenocyte-targeted mouse knockouts (Scx^Cre;Vhl^(f/f), Scx^Cre;Vhl^(f/f);Hif1a^(f/f), Scx^Cre;Vhl^(f/f);Vegfa^(+/f)) · mouse · n = n=3-10 mice per genotype per assay (n=8 for RNA-seq) · GSE276425
  • Primary human gracilis tenocytes under cyclic uniaxial stretching in silicone chambers and VHL CRISPR KO · human · n = n=9 donors (27 chambers) for Ca2+; n=6 for HIF1a and VEGFA
  • Murine surgical synergist ablation (SynAb) plantaris tendon overload in WT and Scx^Cre;Hif1a^(f/f) · mouse · n = n=5-9 mice per group at 12 weeks post-surgery
Methods & tools
Kallisto, DESeq2, EnrichR, fgsea, MaxQuant, Andromeda, Omics Playground Suite, DEP, limma, ImageJ, FlowJo, Matlab
Reagents & environment
Matlab (R2023a), FlowJo Version 10.6.1, MaxQuant v1.6.17
Reproducibility gaps
Mouse sequencing data are at GEO GSE276425; proteomics and human sequencing raw data are available upon request, and custom Matlab/Ca2+ scripts have no public repository URL.
Limitations (3)
  • The human rotator cuff tear label-free proteomics analysis had a small sample size (n=4) and used healthy gracilis tendons (n=4) rather than healthy rotator cuff tendons as controls. · stated by the authors
  • Mouse genetic experiments used a constitutive Scx^Cre driver rather than an inducible Scx^CreERT2 system because the avascularity of adult tendons limits tamoxifen delivery and Cre recombination efficiency. · stated by the authors
  • Genetically induced and surgical synergist ablation overload mouse models of tendinopathy may not fully recapitulate chronic human tendinopathy. · stated by the authors

Read this if you study tendon mechanobiology, extracellular matrix collagen crosslinking, or hypoxia signaling pathways in musculoskeletal degeneration and overload.

Citations
12
FWCI
67.58
Field percentile
top 1%

Abstract

Tendons are mostly avascular dense connective tissues that link muscles to bones, withstanding some of the highest mechanical stresses in the body. Mechanical overload and tissue hypervascularity are implicated in tendinopathy, a common musculoskeletal disorder, but mechanistic understanding of their roles is largely lacking. Here, we identify HIF1 not only as a marker but as a driver of tendinopathy. Initial histological and multi-omics evaluation of human tendinopathic samples revealed extensive extracellular matrix remodeling, including pathological collagen crosslinking coinciding with active hypoxic signaling. Hypothesizing a causal contribution of hypoxia signaling, we generated mice with tenocyte-targeted deletions of the Von Hippel-Lindau (VHL) gene, which controls hypoxia signaling by regulating HIF degradation. We demonstrated that VHL inactivation suffices to induce pathological hallmarks of tendinopathy, such as collagen matrix disorganization, crosslinking, altered mechanics and neuro-vascular ingrowth. This phenotype was HIF1-dependent, since co-deleting HIF1 rescued tendon morphology and mechanics. Moreover, deleting vascular endothelial growth factor A (VEGFA) alongside VHL effectively decoupled the effects of vascular ingrowth from persistently aberrant extracellular matrix remodeling and mechanical dysfunction, emphasizing a direct role of HIF1 in driving tendon disease that is independent of angiogenesis. Mechanistically, we linked tendon mechanical overload to the onset of HIF1 signaling in primary cultured human tendon cells. Furthermore, genetically removing HIF1 from tenocytes prevented aberrant tendon remodeling in response to chronic overload. These findings position HIF1 signaling as a central driver of tendinopathy that acts through a maladaptive tissue response to chronic overload, providing mechanistic insights that could be leveraged for improved therapeutic approaches. One Sentence SummaryHIF1 activation promotes tendinopathy and its inhibition prevents overload-induced maladaptation, suggesting therapeutic potential.

Reproducibility ledger

Nobody has reported trying to reproduce this paper yet. Did you replicate an experiment or run the code? Your report saves the next lab a week.

Sign in to file a reproducibility report.

Related papers

Similarity Map
SelectedSame fieldCross-field
THISZhao '19Steltzer '26Larson '26Zhang '26Disser '19Hold '25
73% semantic matchCell Biology
G. Zhao, J. Zhang, D. Nie+4 more·bioRxiv·Aug 29, 2019