The University of Toledo Translation Journal of Medical Sciences 
Rheumatology Abstract, Department of Medicine Research Symposium UTJMS 2023 May 05; 11(1):e1-e1 

Activation of the Transient Receptor Potential Ion 
Channel TRMP8 Mediates Upregulation 0f Profibrotic 
Genes, A New Pathway to Tissue Fibrosis 
Yongqing Wang, PhD1*, John Y. Jun, MD2; and Bashar Kahaleh, MD3

1Division of Pulmonology, Department of Medicine, The University of Toledo, 
Toledo, OH 43614 
2Division of Endocrinology, Diabetes, and Metabolism, The University of Toledo, 
Toledo, OH 43614 
3Division of Rheumatology, Department of Medicine, The University of Toledo, 
Toledo, OH 43614 

*Corresponding author: yongquing.wang2@utoledo.edu

Published: 05 May 2023 

Introduction: Enhanced cold sensitivity is an early and consistent phenomenon in scleroderma (SSc). 
TRPM8 protein is cold-and menthol-sensing calcium (Ca2+) ion channel. In this study, we evaluated 
TRPM8 expression, the effects of TRPM8 activation on fibroblast (FB) fibrotic gene expression, and 
intracellular signaling. 

Methods: FBs were isolated from involved SSc skin and matched control subjects. TRPM8 activation in 
FBs was triggered by the TRPM8 agonist menthol (MT) or by exposure of cells to cold (18C°). 
Intracellular calcium concentration ([Ca2+] i) was determined using Fura-2 or Fura-4. The mRNA and 
protein expression levels were determined by qPCR  and WB . The production of ROS  was detected by 
dihydroethidium (DHE). SMAD3 binding to the CTGF promoter region was detected by chromatin 
immunoprecipitation assay (ChIP). 

Results: TRPM8 is expressed in dermal FBs. The expression levels of TRPM8 were significantly higher 
in SSc-FBs and SSc-skin biopsies. MT or cold exposure increased [Ca2+]}i, enhanced expression of 
COL1A1, aSMA, FN, and CTGF, and also evoked production of intracellular ROS. SSc-FBs were more 
sensitive to MT or cold than normal FBs. These effects were blocked by the addition of Capsazepine, or 
TRPM8 siRNA, or antioxidants. Moreover, MT induced SMAD3 phosphorylation and nuclear 
accumulation. Chip assay confirmed that SMAD3 is recruited to the CTGF promoter after MT 
stimulation in FBs.   

Conclusion: Functional TRPM8 is expressed in human dermal FBs and enhanced expression was 
observed in SSc FBs and skin. The activation of TRPM8 mediated enhanced expression of the 
profibrotic genes in FBs via the calcium-ROS-SMAD3 signaling pathway. 

https://dx.doi.org/10.46570/utjms.vol11-2023-620 

https://dx.doi.org/10.46570/utjms.vol11-2023-620
mailto:yongquing.wang2@utoledo.edu