Percutaneous transluminal angioplasty in patients with peripheral arterial disease does not affect circulating monocyte subpopulations

Monocytes are mononuclear cells characterized by distinct morphology and expression of CD14 and CD16 surface receptors. Classical, quiescent monocytes are positive for CD14 (lipopolysaccharide receptor) but do not express Fc gamma receptor III (CD16). Intermediate monocytes coexpress CD16 and CD14. Nonclassical monocytes with low expression of CD14 represent mature macrophage-like monocytes. Monocyte behavior in peripheral arterial disease (PAD) and during vessel wall directed treatment is not well defined. This observation study aimed at monitoring of acute changes in monocyte subpopulations during percutaneous transluminal angioplasty (PTA) in PAD patients. Patients with Rutherford 3 and 4 PAD with no signs of inflammatory process underwent PTA of iliac, femoral, or popliteal segments. Flow cytometry for CD14, CD16, HLA-DR, CD11b, CD11c, and CD45RA antigens allowed characterization of monocyte subpopulations in blood sampled before and after PTA (direct angioplasty catheter sampling). Patients were clinically followed up for 12 months. All 61 enrolled patients completed 12-month follow-up. Target vessel failure occurred in 12 patients. While absolute counts of monocyte were significantly lower after PTA, only subtle monocyte activation after PTA (CD45RA and β-integrins) occurred. None of the monocyte parameters correlated with long-term adverse clinical outcome. Changes in absolute monocyte counts and subtle changes towards an activation phenotype after PTA may reflect local cell adhesion phenomenon in patients with Rutherford 3 or 4 peripheral arterial disease

Systemic and local vascular inflammation and arterial reactive oxygen species generation in patients with advanced cardiovascular diseases

BackgroundSystemic inflammation may cause endothelial activation, mediate local inflammation, and accelerate progression of atherosclerosis. We examined whether the levels of circulating inflammatory cytokines reflect local vascular inflammation and oxidative stress in two types of human arteries.MethodsHuman internal mammary artery (IMA) was obtained in 69 patients undergoing coronary artery bypass graft (CABG) surgery and left anterior descending (LAD) artery was obtained in 17 patients undergoing heart transplantation (HTx). Plasma levels of tumor necrosis factor α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) were measured using ELISA, high-sensitivity C-reactive protein (hs-CRP) was measured using Luminex, and mRNA expression of proinflammatory cytokines in the vascular tissues was assessed. Furthermore, formation of superoxide anion was measured in segments of IMA using 5 uM lucigenin-dependent chemiluminescence. Vascular reactivity was measured using tissue organ bath system.ResultsTNF-α, IL-6 and IL-1β mRNAs were expressed in all studied IMA and LAD segments. Plasma levels of inflammatory cytokines did not correlate with vascular cytokine mRNA expression neither in IMA nor in LAD. Plasma TNF-α and IL-6 correlated with hs-CRP level in CABG group. Hs-CRP also correlated with TNF-α in HTx group. Neither vascular TNF-α, IL-6 and IL-1β mRNA expression, nor systemic levels of either TNF-α, IL-6 and IL-1β were correlated with superoxide generation in IMAs. Interestingly, circulating IL-1β negatively correlated with maximal relaxation of the internal mammary artery (r = −0.37, p = 0.004). At the same time the mRNA expression of studied inflammatory cytokines were positively associated with each other in both IMA and LAD. The positive correlations were observed between circulating levels of IL-6 and TNF-α in CABG cohort and IL-6 and IL-1β in HTx cohort.ConclusionsThis study shows that peripheral inflammatory cytokine measurements may not reflect local vascular inflammation or oxidative stress in patients with advanced cardiovascular disease (CVD). Circulating pro-inflammatory cytokines generally correlated positively with each other, similarly their mRNA correlated in the arterial wall, however, these levels were not correlated between the studied compartments

Role of chemokine RANTES in the regulation of perivascular inflammation, T-cell accumulation, and vascular dysfunction in hypertension.

Recent studies have emphasized the role of perivascular inflammation in cardiovascular disease. We studied mechanisms of perivascular leukocyte infiltration in angiotensin II (Ang II)-induced hypertension and their links to vascular dysfunction. Chronic Ang II infusion in mice increased immune cell content of T cells (255 ± 130 to 1664 ± 349 cells/mg; P \u3c 0.01), M1 and M2 macrophages, and dendritic cells in perivascular adipose tissue. In particular, the content of T lymphocytes bearing CC chemokine receptor (CCR) 1, CCR3, and CCR5 receptors for RANTES chemokine was increased by Ang II (CCR1, 15.6 ± 1.5% vs. 31 ± 5%; P \u3c 0.01). Hypertension was associated with an increase in perivascular adipose tissue expression of the chemokine RANTES (relative quantification, 1.2 ± 0.2 vs. 3.5 ± 1.1; P \u3c 0.05), which induced T-cell chemotaxis and vascular accumulation of T cells expressing the chemokine receptors CCR1, CCR3, and CCR5. Mechanistically, RANTES(-/-) knockout protected against vascular leukocyte, and in particular T lymphocyte infiltration (26 ± 5% in wild type Ang II vs. 15 ± 4% in RANTES(-/-)), which was associated with protection from endothelial dysfunction induced by Ang II. This effect was linked with diminished infiltration of IFN-γ-producing CD8(+) and double-negative CD3(+)CD4(-)CD8(-) T cells in perivascular space and reduced vascular oxidative stress while FoxP3(+) T-regulatory cells were unaltered. IFN-γ ex vivo caused significant endothelial dysfunction, which was reduced by superoxide anion scavenging. In a human cohort, a significant inverse correlation was observed between circulating RANTES levels as a biomarker and vascular function measured as flow-mediated dilatation (R = -0.3, P \u3c 0.01) or endothelial injury marker von Willebrand factor (R = +0.3; P \u3c 0.01). Thus, chemokine RANTES is important in the regulation of vascular dysfunction through modulation of perivascular inflammation.-Mikolajczyk, T. P., Nosalski, R., Szczepaniak, P., Budzyn, K., Osmenda, G., Skiba, D., Sagan, A., Wu, J., Vinh, A., Marvar, P. J., Guzik, B., Podolec, J., Drummond, G., Lob, H. E., Harrison, D. G., Guzik, T. J. Role of chemokine RANTES in the regulation of perivascular inflammation, T-cell accumulation, and vascular dysfunction in hypertension

Phagocytosis of Staphylococcus aureus by Macrophages Exerts Cytoprotective Effects Manifested by the Upregulation of Antiapoptotic Factors

It is becoming increasingly apparent that Staphylococcus aureus are able to survive engulfment by macrophages, and that the intracellular environment of these host cells, which is essential to innate host defenses against invading microorganisms, may in fact provide a refuge for staphylococcal survival and dissemination. Based on this, we postulated that S. aureus might induce cytoprotective mechanisms by changing gene expression profiles inside macrophages similar to obligate intracellular pathogens, such as Mycobacterium tuberculosis. To validate our hypothesis we first ascertained whether S. aureus infection could affect programmed cell death in human (hMDMs) and mouse (RAW 264.7) macrophages and, specifically, protect these cells against apoptosis. Our findings indicate that S. aureus-infected macrophages are more resistant to staurosporine-induced cell death than control cells, an effect partly mediated via the inhibition of cytochrome c release from mitochondria. Furthermore, transcriptome analysis of human monocyte-derived macrophages during S. aureus infection revealed a significant increase in the expression of antiapoptotic genes. This was confirmed by quantitative RT-PCR analysis of selected genes involved in mitochondria-dependent cell death, clearly showing overexpression of BCL2 and MCL1. Cumulatively, the results of our experiments argue that S. aureus is able to induce a cytoprotective effect in macrophages derived from different mammal species, which can prevent host cell elimination, and thus allow intracellular bacterial survival. Ultimately, it is our contention that this process may contribute to the systemic dissemination of S. aureus infection

Role of inflammatory chemokines in hypertension

Hypertension is associated with immune cells activation and their migration into the kidney, vasculature, heart and brain. These inflammatory mechanisms are critical for blood pressure regulation and mediate target organ damage, creating unique novel targets for pharmacological modulation. In response to angiotensin II and other pro-hypertensive stimuli, the expression of several inflammatory chemokines and their receptors is increased in the target organs, mediating homing of immune cells. In this review, we summarize the contribution of key inflammatory chemokines and their receptors to increased accumulation of immune cells in target organs and effects on vascular dysfunction, remodeling, oxidative stress and fibrosis, all of which contribute to blood pressure elevation. In particular, the role of CCL2, CCL5, CXCL8, CXCL9, CXCL10, CXCL11, CXCL16, CXCL1, CX3CL1, XCL1 and their receptors in the context of hypertension is discussed. Recent studies have tested the efficacy of pharmacological or genetic targeting of chemokines and their receptors on the development of hypertension. Promising results indicate that some of these pathways may serve as future therapeutic targets to improve blood pressure control and prevent target organ consequences including kidney failure, heart failure, atherosclerosis or cognitive impairment

TNF-α Inhibitors Decrease Classical CD14hiCD16− Monocyte Subsets in Highly Active, Conventional Treatment Refractory Rheumatoid Arthritis and Ankylosing Spondylitis

Monocytes are pivotal cells in inflammatory joint diseases. We aimed to determine the effect of TNF-α inhibitors (TNFi) on peripheral blood monocyte subpopulations and their activation in ankylosing spondylitis (AS) and rheumatoid arthritis (RA) patients with high disease activity. To address this, we studied 50 (32 AS, 18 RA) patients with highly active disease with no prior history of TNFi use who were recruited and assigned to TNFi or placebo treatment for 12 weeks. Cytometric and clinical assessment was determined at baseline, four, and 12 weeks after initiation of TNFi treatment. We observed that treatment with TNFi led to a significant decrease in CD14hiCD16− monocytes in comparison to placebo, while circulating CD14dimCD16+ monocytes significantly increased. The TNFi-induced monocyte subset shifts were similar in RA and AS patients. While the percentage of CD14dimCD16+ monocytes increased, expression of CD11b and CD11c integrins on their surface was significantly reduced by TNFi. Additionally, CD45RA+ cells were more frequent. The shift towards nonclassical CD14dimCD16+ monocytes in peripheral blood due to TNFi treatment was seen in both AS and RA. This may reflect reduced recruitment of these cells to sites of inflammation due to lower inflammatory burden, which is associated with decreased disease activity

Th1‐type immune responses to Porphyromonas gingivalis

Background and Purpose: Emerging evidence indicates that hypertension is mediated by immune mechanisms. We hypothesized that exposure to Porphyromonas gingivalis antigens, commonly encountered in periodontal disease, can enhance immune activation in hypertension and exacerbate blood pressure elevation, vascular inflammation and vascular dysfunction. Experimental Approach: Th1 immune response were elicited through immunizations using Porphyromonas gingivalis lysate antigens (10ug) conjugated with aluminium oxide (50ug) and IL‐12 (1ug). The hypertension and vascular endothelial dysfunction evoked by sub‐pressor doses of Angiotensin II (0.25mg/kg/day) were studied and vascular inflammation was quantified by flow cytometry and real time polymerase chain reaction. Key Results: Systemic T cell activation, characteristic for hypertension, was exacerbated by P. gingivalis antigen stimulations. This translated into increased aortic vascular inflammation with enhanced leukocytes, in particular, T cell and macrophage infiltration. Expression of the Th1 cytokines, Interferon‐γ and Tumour Necrosis Factor‐α and the transcription factor TBX21 was increased in aortas of P. gingivalis/Interleukin‐12/aluminium oxide immunized mice, while IL‐4 and TGF‐β were unchanged. These immune changes in mice with induced T helper type 1 immune responses were associated with enhanced blood pressure elevation and endothelial dysfunction compared to control mice in response to two weeks infusion of a sub‐pressor dose of Angiotensin II. Conclusion and Implications: These studies support the concept that Th1 immune responses induced by bacterial antigens such as P. gingivalis can increase sensitivity to sub‐pressor pro‐hypertensive insults such as low dose Angiotensin II, therefore providing a mechanistic link between chronic infection such as periodontitis and hypertension

Effects of controlled physical activity on immune cell phenotype in peripheral blood in prehypertension - studies in preclinical model and randomised crossover study

Hypertension (HT) is a global public health issue. There are many behavioural risk factors including unhealthy diet, tobacco use and alcohol consumption as well physical inactivity that contribute to the development of high blood pressure (BP) and its complications. Favourable effect of regular physical activity on treatment or prevention of hypertension by improvement of endothelial function is widely accepted however little is known about its relationship with immune system. Thus, the aim of this study was to assess the role of moderate regular physical activity on immune cell phenotype. T cell and monocyte subsets were characterised in 31 subjects with prehypertension (130 - 139 mmHg systolic and 85 - 89 mmHg diastolic blood pressure) who participated in moderate training (3 times/week) on cyclometers for 3 months in crossover study design. Complementary study was performed in murine model of Ang II-induced hypertension and ten-week-old animals were trained on a treadmill (5 times/week, 1 hour) for 2 weeks before and 1.5 weeks after minipumps implantation. In the context of elevated blood pressure regular physical activity had modest influence on immune cell phenotype. Both in human study and murine model we did not observe effects of applied exercise that can explain the mechanism of BP reduction after short-term regular training. Twelve-weeks regular training did not affect the activation status of T lymphocytes measured as expression of CD69, CD25 and CCR5 in human study. Physical activity resulted in higher expression of adhesion molecule CD11c on CD16+ monocytes (especially CD14 high) without any changes in leukocytes subpopulation counts. Similar results were observed in murine model of hypertension after the training. However the training caused significant decrease of CCR5 and CD25 expressions (measured as a mean fluorescence intensity) on CD8+ T cells infiltrating perivascular adipose tissue. Our studies show modest regulatory influence of moderate training on inflammatory markers in prehypertensive subjects and murine model of Ang II induced hypertension