L-Carnitine Suppresses Transient Receptor Potential Vanilloid Type 1 Activation in Human Corneal Epithelial Cells

Research output: Contribution to journalResearch articleContributedpeer-review


  • Alexander Lucius - , Charité – Universitätsmedizin Berlin (First author)
  • Sirjan Chhatwal - , Charité – Universitätsmedizin Berlin (Author)
  • Monika Valtink - , Institute of Anatomy, Medical Faculty Carl Gustav Carus (Author)
  • Peter S. Reinach - , Wenzhou Medical University (Author)
  • Aruna Li - , Charité – Universitätsmedizin Berlin (Author)
  • Uwe Pleyer - , Charité – Universitätsmedizin Berlin (Author)
  • Stefan Mergler - , Charité – Universitätsmedizin Berlin (Author)


Tear film hyperosmolarity induces dry eye syndrome (DES) through transient receptor potential vanilloid type 1 (TRPV1) activation. L-carnitine is a viable therapeutic agent since it protects against this hypertonicity-induced response. Here, we investigated whether L-carnitine inhibits TRPV1 activation by blocking heat- or capsaicin-induced increases in Ca2+ influx or hyperosmotic stress-induced cell volume shrinkage in a human corneal epithelial cell line (HCE-T). Single-cell fluorescence imaging of calcein/AM-loaded cells or fura-2/AM-labeled cells was used to evaluate cell volume changes and intracellular calcium levels, respectively. Planar patch-clamp technique was used to measure whole-cell currents. TRPV1 activation via either capsaicin (20 µmol/L), hyperosmolarity (≈450 mosmol/L) or an increase in ambient bath temperature to 43 °C induced intracellular calcium transients and augmented whole-cell currents, whereas hypertonicity induced cell volume shrinkage. In contrast, either capsazepine (10 µmol/L) or L-carnitine (1–3 mmol/L) reduced all these responses. Taken together, L-carnitine and capsazepine suppress hypertonicity-induced TRPV1 activation by blocking cell volume shrinkage.


Original languageEnglish
Article number11815
Number of pages15
JournalInternational Journal of Molecular Sciences
Issue number14
Publication statusPublished - 23 Jul 2023

External IDs

Scopus 85166029916
ORCID /0000-0003-3205-1876/work/142660952
Mendeley 52b3c8b5-43ea-3fa6-ab8e-e78a56ddfa10
PubMed 37511574


DFG Classification of Subject Areas according to Review Boards

Subject groups, research areas, subject areas according to Destatis


  • L-carnitine, cell volume, human corneal epithelium, hypertonic cell shrinkage, intracellular Ca signaling, intracellular Ca2+ signaling, planar patch-clamp technique, transient receptor potential channel vanilloid 1, Antineoplastic Agents/metabolism, Epithelial Cells/metabolism, Capsaicin/pharmacology, Humans, TRPV Cation Channels/metabolism, Carnitine/pharmacology, Calcium/metabolism

Library keywords