CAND1 drives intestinal ischemia/reperfusion injury via SCFFBXO6-PKM2-mediated mitochondrial fission and apoptosis

  • Free Radic Biol Med. 2026 Jun 15:254:181-195. doi: 10.1016/j.freeradbiomed.2026.06.029.
Miaomiao Qiang  1 ,  Yan Zhao  2 ,  Guorong Wang  1 ,  Zhao Chen  1 ,  Feng Zhang  1 ,  Zhanyu Wang  1 ,  Guangzhi Wang  1 ,  Chengjun Zhuang  3 ,  Shili Ning  4 ,  Jihong Yao  5 ,  Xiaofeng Tian  6
Affiliations
  • 1. Department of General Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, 116023, China.
  • 2. Department of Pharmacology, Dalian Medical University, Dalian, 116044, China.
  • 3. Department of Intensive Care Unit, The Second Affiliated Hospital of Dalian Medical University, Dalian, 116023, China.
  • 4. Department of General Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, 116023, China. Electronic address: [email protected].
  • 5. Department of Pharmacology, Dalian Medical University, Dalian, 116044, China. Electronic address: [email protected].
  • 6. Department of General Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, 116023, China. Electronic address: [email protected].
PMID: 42297194 DOI: 10.1016/j.freeradbiomed.2026.06.029
Abstract

Background: Intestinal ischemia/reperfusion (I/R) injury is a critical clinical condition associated with high mortality, in which the ubiquitin‒proteasome system (UPS) plays a pivotal pathogenic role. Cullin-associated and neddylation-dissociated 1 (CAND1), a critical regulator of cellular protein homeostasis, governs the ubiquitination and degradation of abnormal protein substrates by regulating the assembly of SKP1‒Cullin1‒F-box (SCF) E3 ubiquitin Ligase complexes. However, the mechanisms by which CAND1 regulates SCF complex assembly and its potential therapeutic role in intestinal I/R injury remain unclear.

Objectives: This study aims to elucidate the molecular mechanisms by which CAND1 mediates intestinal I/R injury and to identify potential therapeutic strategies targeting CAND1.

Methods: Intestinal I/R was induced by superior mesenteric artery (SMA) occlusion in mice. Four weeks before I/R challenge, AAV-CAND1 was injected into the mice via the tail vein. Evodiamine (evo) was administered daily via intraperitoneal injection for three days before I/R challenge. Caco-2 cells were subjected to hypoxia/reoxygenation (H/R) treatment in vitro to simulate intestinal I/R in mice.

Results: Excessive oxidative stress during intestinal I/R injury triggers mitochondrial fission and Apoptosis. We identified CAND1 as a key regulator in this process, demonstrating upregulated expression during intestinal I/R injury. CAND1 knockdown attenuated Reactive Oxygen Species (ROS) overproduction, mitochondrial fission, and Apoptosis. Mechanistically, CAND1 inhibited Cullin1-FBXO6-PKM2 complex assembly and reduced PKM2 ubiquitination and degradation, thereby increasing PKM2 stability. Phosphorylated PKM2 formed dimers and translocated to mitochondria, where it activated Drp1-dependent fission pathway, worsening oxidative stress and Apoptosis. Through molecular docking, evo was identified as a potential small-molecule candidate targeting CAND1. CAND1 may be inhibited by evo, thereby alleviating intestinal I/R injury.

Conclusion: CAND1 suppresses Cullin1-FBXO6-PKM2 complex assembly and PKM2 ubiquitination, promoting PKM2 dimerization-mediated mitochondrial fission and Apoptosis in intestinal I/R injury. CAND1 is likely inhibited by evo, thereby alleviating mitochondrial dynamic alterations and cell death during intestinal I/R injury.

Keywords
Apoptosis; CAND1; Intestinal ischemia/reperfusion (I/R) injury; Mitochondrial fusion/fission; Ubiquitination.
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