ClpP deficiency attenuates contrast-induced HK-2 cell injury through changes associated with mitochondrial dynamics and apoptosis

  • PLoS One. 2026 Jul 2;21(7):e0352422. doi: 10.1371/journal.pone.0352422.
Jing Wang  1  2 ,  Lei Wang  3 ,  Liang Xie  2 ,  Chengchun Tang  1  4
Affiliations
  • 1. School of Medicine, Southeast University, Nanjing, Jiangsu, China.
  • 2. Department of General Medicine, Women's Hospital of Nanjing Medical University. Nanjing Women and Children's Healthcare Hospital, Nanjing, Jiangsu, China.
  • 3. Jinling Hospital Department of Cardiology, Nanjing University, School of Medicine, Nanjing, Jiangsu, China.
  • 4. Department of Cardiology, Zhongda Hospital of Southeast University Medical School, Nanjing, Jiangsu, China.
PMID: 42391150 DOI: 10.1371/journal.pone.0352422
Abstract

Background: Contrast-associated acute kidney injury (CA-AKI) is a renal impairment that occurs after several days of intravascular administration of iodine-containing contrast media. ClpP is a key protease that plays an important role in cellular mitochondrial function. This study investigated the role of ClpP in mitochondrial dynamics and early injury in an in‑vitro CA‑AKI model.

Methods: mRNA Sequencing was performed on HK-2 cells with or without iohexol exposure. Cell viability, mitochondrial dynamics-related protein expression, mitochondrial membrane potential (MMP), and cell Apoptosis were assessed by cell counting kit-8, immunoblotting, JC‑1 staining and flow cytometry, respectively.

Results: Iohexol treatment at 80 mg I/mL reduced HK-2 cell viability to 63.44%, induced mitochondrial fission, inhibited mitochondrial fusion and promoted Apoptosis. mRNA Sequencing revealed significant upregulation of Opa1 and ClpP gene expression, as well as alterations in proteasome‑related signaling in iohexol-induced HK-2 cell. Western blot analysis further confirmed elevated ClpP protein expression after iohexol exposure. Importantly, ClpP knockdown partially restored MMP, increased Opa1 expression, improved mitochondrial morphology, and alleviated iohexol‑induced Apoptosis.

Conclusion: ClpP deficiency may exert cytoprotective effects against iohexol-induced HK-2 cell injury, at least partly through changes associated with mitochondrial dynamics, partial preservation of MMP, and attenuation of Apoptosis. These findings suggest that ClpP may represent a potential molecular target for further investigation in CA-AKI.

Products