Atorvastatin suppresses vascular hypersensitivity and remodeling induced by transient adventitial administration of lipopolysaccharide in rats

Statins change the cytokine profile in Trypanosoma cruzi-infected U937 macrophages and murine cardiac tissue through Rho-associated kinases inhibition

Introduction

Chronic Chagasic cardiomyopathy (CCC), caused by the protozoan Trypanosoma cruzi, is the most severe manifestation of Chagas disease.CCC is characterized by cardiac inflammation and fibrosis caused by a persistent inflammatory response. Following infection, macrophages secrete inflammatory mediators such as IL-1β, IL-6, and TNF-α to control parasitemia. Although this response contains parasite infection, it causes damage to the heart tissue. Thus, the use of immunomodulators is a rational alternative to CCC. Rho-associated kinase (ROCK) 1 and 2 are RhoA-activated serine/threonine kinases that regulate the actomyosin cytoskeleton. Both ROCKs have been implicated in the polarization of macrophages towards an M1 (pro-inflammatory) phenotype. Statins are FDA-approved lipid-lowering drugs that reduce RhoA signaling by inhibiting geranylgeranyl pyrophosphate (GGPP) synthesis. This work aims to identify the effect of statins on U937 macrophage polarization and cardiac tissue inflammation and its relationship with ROCK activity during T. cruzi infection.

Methods

PMA-induced, wild-type, GFP-, CA-ROCK1- and CA-ROCK2-expressing U937 macrophages were incubated with atorvastatin, or the inhibitors Y-27632, JSH-23, TAK-242, or C3 exoenzyme incubated with or without T. cruzi trypomastigotes for 30 min to evaluate the activity of ROCK and the M1 and M2 cytokine expression and secretion profiling. Also, ROCK activity was determined in T. cruzi-infected, BALB/c mice hearts.

Results

In this study, we demonstrate for the first time in macrophages that incubation with T. cruzi leads to ROCK activation via the TLR4 pathway, which triggers NF-κB activation. Inhibition of ROCKs by Y-27632 prevents NF-κB activation and the expression and secretion of M1 markers, as does treatment with atorvastatin. Furthermore, we show that the effect of atorvastatin on the NF-kB pathway and cytokine secretion is mediated by ROCK. Finally, statin treatment decreased ROCK activation and expression, and the pro-inflammatory cytokine production, promoting anti-inflammatory cytokine expression in chronic chagasic mice hearts.

Conclusion

These results suggest that the statin modulation of the inflammatory response due to ROCK inhibition is a potential pharmacological strategy to prevent cardiac inflammation in CCC.

Rosmarinic Acid Attenuates the Lipopolysaccharide-Provoked Inflammatory Response of Vascular Smooth Muscle Cell via Inhibition of MAPK/NF-κB Cascade

Rosmarinic acid (RA) is a phenolic compound that has several bioactivities, such as anti-inflammatory and antioxidant activities. Here, we further investigate the anti-inflammatory effect of RA on rat A7r5 aortic smooth muscle cells with exposure to lipopolysaccharide (LPS). Our findings showed that low-dose RA (10–25 μM) did not influence the cell viability and morphology of A7r5 cells and significantly inhibited LPS-induced mRNA expression of the pro-inflammatory mediators TNFα, IL-8, and inducible NO synthase (iNOS). Consistently, RA reduced the production of TNFα, IL-8, and NO by A7r5 cells with exposure to LPS. Signaling cascade analysis showed that LPS induced activation of Erk, JNK, p38 mitogen-activated protein kinase (MAPK), and NF-κB, and RA treatments attenuated the activation of the three MAPKs and NF-κB. Moreover, cotreatment with RA and Erk, JNK, p38 MAPK, or NF-κB inhibitors further downregulated the mRNA expression of TNFα, IL-8, and iNOS, and decreased the production of TNFα, IL-8, and NO by A7r5 cells. Taken together, these findings indicate that RA may ameliorate the LPS-provoked inflammatory response of vascular smooth muscle cells by inhibition of MAPK/NF-κB signaling.