Effects of local cryotherapy on systemic endothelial activation, dysfunction, and vascular inflammation in adjuvant-induced arthritis (AIA) rats

Abstract

Aim This study explored the systemic vascular effects of local cryotherapy with a focus on endothelial changes and arterial inflammation in the model of rat adjuvant-induced arthritis (AIA). Methods Cryotherapy was applied twice a day on hind paws of AIA rats from the onset of arthritis to the acute inflammatory phase. Endothelial activation was studied in the aorta by measuring the mRNA levels of chemokines (CXCL-1, MCP-1 (CCL-2), MIP-1α (CCL-3)) and adhesion molecules (ICAM-1, VCAM-1) by qRT-PCR. Endothelial dysfunction was measured in isolated aortic and mesenteric rings. Aortic inflammation was evaluated via the mRNA expression of pro-inflammatory cytokines (TNF-α, IL-6) by qRT-PCR and leucocyte infiltration analysis (flow cytometry). Plasma levels of TNF-α, IL-6, IL-1β, IL-17A, and osteoprotegerin (OPG) were measured using Multiplex/ELISA. Results AIA was associated with an increased aortic expression of CXCL-1 and ICAM-1 as well as an infiltration of leucocytes and increased mRNA expression of IL-6, IL-1β, and TNF-α. Local cryotherapy, which decreased arthritis score and structural damages, reduced aortic mRNA expression of CXCL-1, IL-6, IL-1β, and TNF-α, as well as aortic infiltration of leucocytes (T lymphocytes, monocytes/macrophages, neutrophils) and improved acetylcholine-induced vasorelaxation in the aorta and mesenteric arteries. Plasma levels of IL-17A and OPG were significantly reduced by cryotherapy, while the number of circulating leucocytes was not. IL-17A levels positively correlated with endothelial activation and dysfunction. Conclusion In the AIA model, local cryotherapy reduced systemic endothelial activation, immune cell infiltration, and endothelial dysfunction. Mechanistically, the reduction of circulating levels of IL-17A appears as the possible link between joint cooling and the remote vascular effects.

The Effect of Physical Activity and Repeated Whole-Body Cryotherapy on the Expression of Modulators of the Inflammatory Response in Mononuclear Blood Cells among Young Men

“…These clinical observations are congruent with the molecular data obtained in the current study, which illustrate an upsurge in the mRNA levels of genes associated with antioxidative function and mitochondrial integrity, possibly reflecting an augmented recovery process and attenuation of inflammatory responses. Notably, the reduction of mRNA expression in ICAM-1 observed post-WBC is in harmony with the findings of Peyronnel et al, indicative of a systemic anti-inflammatory effect [32]. Analysis of expression using a greater number of time points could contribute to understanding the mechanisms of WBC action [33].…”