Interleukin-10 attenuates the response to vascular injury
ABSTRACT The inflammatory response to vascular injury is characterized by expression of cytokines, growth factors, and chemokines that conspire to promote vessel remodeling and intimal hyperplasia (IH). Interleukin-10 (IL-10) is a multifunctional cytokine that has several anti-inflammatory properties in vitro. Few studies have evaluated the effects of IL-10 in experimental atherosclerosis. The purpose of the present study was to determine the influence of IL-10 on vascular inflammation and IH following mechanical injury.
Wire carotid injury was performed in wild-type (WT) mice with and without IL-10 treatment. Immunohistochemistry, PCR, and ELISA assays were used to examine vessel production of basic fibroblast growth factor (bFGF), monocyte chemotactic protein-1 (MCP-1), and nuclear factor kappa B (NFkappaB). Vessels were morphometrically analyzed for IH.
Carotid injury induced early expression of MCP-1 and bFGF that was abrogated in mice treated with IL-10. Similarly, injury-induced expression of NFkappaB message and protein was attenuated in mice receiving exogenous IL-10. Compared to untreated mice, IL-10 markedly decreased levels of IH. Interestingly, carotid injury in IL-10-deficient mice resulted in an augmented IH response compared to injured WT mice.
In an in vivo model of direct vascular injury, IL-10 decreased expression of the pro-inflammatory transcription factor, NFkappaB, and the mitogenic chemokine and growth factor, MCP-1 and bFGF, respectively. These observations were associated with IL-10-induced attenuation of IH. Furthermore, endogenous IL-10 appeared to suppress the injury response. In conclusion, exogenously delivered IL-10 may represent a clinically relevant anti-inflammatory strategy for post-injury intimal hyperplasia.
- SourceAvailable from: Luciane Alarcão Dias-Melicio
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- "This process makes macrophages important antigen-presenting cells for developing a specific immune response. In this case LDLox is the inducing antigen which causes a Th1 response, followed by production of interferon- gamma (IFN-γ) and tumor necrosis factor -alpha and -beta (TNF-α and TNF-β) and interleukin-12 (IL-12) [4-7]. Thus, IFN-γ has been considered one of the main cytokines released during atherosclerosis which, through an activation process of macrophages, amplifies the actions of these cells but in certain circumstances may lead to apoptosis . "
ABSTRACT: ABSTRACT: Arterial peripheral disease is a condition caused by the blocked blood flow resulting from arterial cholesterol deposits within the arms, legs and aorta. Studies have shown that macrophages in atherosclerotic plaque are highly activated, which makes these cells important antigen-presenting cells that develop a specific immune response, in which LDLox is the inducing antigen. As functional changes of cells which participate in the atherogenesis process may occur in the peripheral blood, the objectives of the present study were to evaluate plasma levels of anti-inflammatory and inflammatory cytokines including TNF-α, IFN-γ, interleukin-6 (IL-6), IL-10 and TGF-β in patients with peripheral arteriosclerosis obliterans, to assess the monocyte activation level in peripheral blood through the ability of these cells to release hydrogen peroxide (H2O2) and to develop fungicidal activity against Candida albicans (C. albicans) in vitro. TNF-α, IFN-γ, IL-6, IL-10 and TGF-β from plasma of patients were detected by ELISA. Monocyte cultures activated in vitro with TNF-alpha and IFN-gamma were evaluated by fungicidal activity against C. albicans by culture plating and Colony Forming Unit (CFU) recovery, and by H2O2 production. Plasma levels of all cytokines were significantly higher in patients compared to those detected in control subjects. Control group monocytes did not release substantial levels of H2O2 in vitro, but these levels were significantly increased after activation with IFN-γ and TNF-α. Monocytes of patients, before and after activation, responded less than those of control subjects. Similar results were found when fungicidal activity was evaluated. The results seen in patients were always significantly smaller than among control subjects. Conclusions: The results revealed an unresponsiveness of patient monocytes in vitro probably due to the high activation process occurring in vivo as corroborated by high plasma cytokine levels.Journal of Inflammation 08/2011; 8(8):23. DOI:10.1186/1476-9255-8-23 · 2.22 Impact Factor
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- "IL-10, an anti-inflammatory cytokine, is a major deactivator of activated, cytokine-producing monocytes and MDMs . It down-regulates transcription of many pro-inflammatory cytokines through the inhibition of nuclear factor kappa B (NFjB) transcription . Fig. 5. "
ABSTRACT: A degradable, polar, hydrophobic, ionic polyurethane (D-PHI), with physical properties comparable to those of peripheral arterial vascular tissue, was evaluated for monocyte interactions with two different physical forms: two-dimensional films and three-dimensional porous scaffolds. Monocytes, isolated from human whole blood, were seeded onto D-PHI films and scaffolds, and differentiated to monocyte-derived macrophages (MDM) for up to 28 days. The effect of surface structure on the MDM phenotype was assessed by assaying: cell attachment (DNA), activation (intracellular protein expression, esterase and acid phosphatase (AP) activity) as well as pro- and anti-inflammatory cytokines (TNF-α and IL-10, respectively). The cells on scaffolds exhibited an initial peak in total protein synthesized per DNA at 3 days; however, both substrates generated similar protein levels per DNA at all other time points. While scaffolds generated more esterase and AP per cell than for films, the cells on films expressed significantly more of these two proteins relative to their total protein produced. At day 7 (acute phase of monocyte activation), cells on films were significantly more activated than monocytes on the scaffolds as assessed by cell morphology and tumor necrosis factor-α and interleukin-10 levels. Histological analysis of scaffolds showed that cells were able to migrate throughout the three-dimensional matrix. By inducing a low inflammatory, high wound-healing phenotype monocyte, the negative effects of the foreign body reaction in vivo may be controlled in a manner possible to direct the vascular tissue cells into the appropriate functional phenotypes necessary for successful tissue engineering.Acta biomaterialia 01/2011; 7(1):115-22. DOI:10.1016/j.actbio.2010.08.014 · 5.68 Impact Factor
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ABSTRACT: Adaptive and innate immune responses play a critical role in the protection against extracellular or intracellular pathogens. The function of these two types of immune responses is coordinated by CD4+ T-helper (Th) cells. Depending on the cytokine environment, Th progenitor (Thp) cells differentiate into three functionally different effector subsets. T-helper-1 (Th1) cells which mediate cell-mediated immunity, T-helper-2 (Th2) which orchestrates humoral immunity and T-helper-17 (Th17) cells key players in autoimmunity response. Cytokine induced transcription factors that are differentially expressed in Th cells are required for the development and commitment to a specific Th lineage. The population of Th2 cells can be subdivided in subpopulations depending on the level of a cytokine and the subsets of cytokines they produce. Very limited information is available about the regulation of cytokine production in this array of Th2 cells. We have recently identified the ETS family transcription factor PU.1 as regulating heterogeneity in Th2 populations. To define additional factors that might contribute to Th2 heterogeneity, we examined the PU.1 interacting protein IFN-regulatory factor (IRF)-4, a transcription factor expressed in lymphocytes and macrophages. When Th2 cells are separated based on levels of IL-10 secretion, IRF4 expression segregates into the subset of Th2 cells expressing high levels of IL-10. To investigate the role of IRF4 in cytokine heterogeneity, Th2 cells were infected with retrovirus expressing IRF4. The cells overexpressing IRF4 secreted significantly higher levels of IL-10 and IL-4 compared to cells infected with a control vector at the same time the level of IL-9 decreases. To understand the mechanism by which IRF4 regulates IL-10 expression in various Th2 cell subpopulations we used co-immunoprecipitation assays to determine transcription factors that interact with IRF4. Our data shows that PU.1, IRF4 and NFATc2 form a complex in Th2 nuclear extract. We also demonstrated by ChIP assay that IRF4 directly binds the Il10 and Il4 loci in a time dependent manner. The role of these protein-protein and protein-DNA complexes and their contribution towards Th2 heterogeneity will be further defined. Understanding the regulation of the anti-inflammatory cytokine IL-10 in Th2 cells may give us a tool to control inflammation.