BHLHE40 drives ferroptosis in Escherichia coli-induced endometrial injury by recruiting HDAC1 to repress CPT1B and impair NRF2 signaling

  • Free Radic Biol Med. 2026 Aug 16:252:509-524. doi: 10.1016/j.freeradbiomed.2026.05.293.
Changning Yuan  1 ,  Jue Wang  1 ,  Zhihao Wang  2 ,  Peng Mao  1 ,  Pengfei Dong  1 ,  Junsheng Dong  1 ,  Long Guo  1 ,  Kangjun Liu  1 ,  Luying Cui  1 ,  Jianji Li  1 ,  Ran Wang  3 ,  Lili Zhang  3 ,  He Tao  3 ,  Xia Meng  4 ,  Heng Wang  5
Affiliations
  • 1. College of Veterinary Medicine, Yangzhou University, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China; Jiangsu Interdisciplinary Center for Zoonoses and Biosafety, Yangzhou University, Yangzhou, 225009, China; Jiangsu Key Laboratory of Zoonotic, Yangzhou University, Yangzhou, 225000, China.
  • 2. Pancreatic Center, Department of Gastroenterology, Yangzhou Key Laboratory of Pancreatic Disease, The Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, 225000, China.
  • 3. Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China.
  • 4. College of Veterinary Medicine, Yangzhou University, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China; Jiangsu Interdisciplinary Center for Zoonoses and Biosafety, Yangzhou University, Yangzhou, 225009, China; Jiangsu Key Laboratory of Zoonotic, Yangzhou University, Yangzhou, 225000, China. Electronic address: [email protected].
  • 5. College of Veterinary Medicine, Yangzhou University, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China; Jiangsu Interdisciplinary Center for Zoonoses and Biosafety, Yangzhou University, Yangzhou, 225009, China; Jiangsu Key Laboratory of Zoonotic, Yangzhou University, Yangzhou, 225000, China. Electronic address: [email protected].
PMID: 42128070 DOI: 10.1016/j.freeradbiomed.2026.05.293
Abstract

Endometritis is a common disease of the reproductive system that leads to decreased fertility and potential miscarriage, resulting in substantial economic losses. Ferroptosis is an iron-dependent mode of cell death driven by lipid peroxidation. Basic helix-loop-helix family member E40 (BHLHE40) has been developed as a molecular marker and a therapeutic target for Bacterial infectious diseases. However, the underlying role of BHLHE40 needs to be further studied. This study investigated whether BHLHE40 drives Escherichia coli (E. coli) -induced endometrial Ferroptosis by transcriptionally repressing carnitine palmitoyltransferase 1B (CPT1B) and attenuating the NRF2 signaling pathway, with the aim of elucidating the regulatory mechanism of the BHLHE40-CPT1B-NRF2 axis. In endometrial tissues from E. coli-infected cows (n = 8 per group, in vivo), the expression of BHLHE40 was increased by 3.6 times (p < 0.05), and its protein level positively correlated with the severity of tissue damage (Pearson r = 0.6722, p = 0.0034). Functionally, knockdown of BHLHE40 conferred significant protection against E. coli-induced cell death (decreased from 36% to 18%, p < 0.01), concurrently reversing the features of Ferroptosis (p < 0.05), including reduced lipid peroxidation, decreased intracellular Fe2+ concentration, and restored glutathione levels and the expression of anti-ferroptosis proteins. Integrated analysis of CUT&Tag and RNA-sequencing data revealed that BHLHE40 binds to the promoter region of CPT1B (enrichment increased by 5 times, p < 0.01) and transcriptionally represses its expression. Further investigation demonstrated that BHLHE40 mediates CPT1B repression by recruiting HDAC1 to the CPT1B promoter, a process reversible upon HDAC1 inhibition. Crucially, BHLHE40-mediated suppression of CPT1B led to functional impairment of the NRF2 signaling pathway. Overexpression of CPT1B inhibited Ferroptosis by reactivating NRF2 and its downstream targets (p < 0.05), whereas inhibition of NRF2 abolished the protective effect (cell death increased from 16% to 27%, p < 0.01), confirming NRF2 as the critical downstream effector. This study elucidates the BHLHE40-CPT1B-NRF2-ferroptosis axis as a novel pathway and potential target for E. coli to cause endometrial epithelial injury.

Keywords
Basic helix-loop-helix family member E40; Bovine; CUT&Tag; Endometritis; Escherichia coli; Ferroptosis.
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