Cav3.2 calcium channels involvement in inflammation and related
pain-like symptoms in murine inflammatory models
Abstract
Background and Purpose T-type calcium channels, mainly the Cav3.2
subtype, are important contributors to the nociceptive signaling
pathway. We investigated their involvement in inflammation and related
pain-like symptoms. Experimental Approach The involvement of Cav3.2 and
T-type channels was investigated using genetic and pharmacological
inhibition to assess mechanical allodynia/hyperalgesia and edema
development in two murine inflammatory pain models. The location of
Cav3.2 involved in pain-like symptoms was studied in mice with Cav3.2
knocked out in C-low threshold mechanoreceptors (C-LTMR) and the use of
ABT-639, a peripherally restricted T-type channel inhibitor. The
anti-edematous effect of Cav3.2 inhibition was investigated in chimeric
mice with immune cells deleted for Cav3.2. Lymphocytes and macrophages
from either green fluorescent protein-targeted Cav3.2 or KO mice were
used to determine the expression of Cav3.2 protein and the functional
status of the cells. Key Results We showed the role of Cav3.2 channels
in the development of pain-like symptoms and edema in the two murine
inflammatory pain models. For the first time, we provide evidence of the
involvement of Cav3.2 channels located on C-LTMRs in inflammatory pain
at both peripheral and primary afferent terminals at the spinal level.
We showed that Cav3.2 channels located in T cells and macrophages
contribute to the inflammatory process. Conclusion and Implications This
work highlights the crucial role of Cav3.2 channels in inflammation and
related pain and suggests that targeting Cav3.2 channels with
pharmacological agents could be an attractive and readily evaluable
strategy in a clinical trial to relieve chronic inflammatory pain in
affected patients.