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Enhancement of MMP-2 and MMP-9 in cardiac myocytes in response to doxorubicin is mediated by the cooperation of ERK, JNK, and p38 kinase pathways, most of which are redox dependent.

Adipose tissue inflammation mediates the association between excessive body fat accumulation and several chronic inflammatory diseases. A high prevalence of obesity-associated adipose tissue inflammation was observed not only in patients with cardiovascular conditions but also in patients with inflammatory bowel diseases, abdominal aortic aneurysm, or cardiorenal syndrome. In addition to excessive caloric intake, other triggers promote visceral adipose tissue inflammation followed by chronic, low-grade systemic inflammation. The infiltration and accumulation of immune cells in the inflamed and hypertrophied adipose tissue promote the production of inflammatory cytokines, contributing to target organ damages. This comorbidity seems to delimit subgroups of individuals with systemic adipose tissue inflammation and more severe chronic inflammatory diseases that are refractory to conventional treatment. This review highlights the association between adipose tissue immune response and the pathophysiology of visceral adiposity-related chronic inflammatory diseases, while suggesting several new therapeutic strategies.

Abstract.Our aim was to define the distribution of monocyte subsets in a cohort of congestive heart failure (CHF) patients, to verify whether increased severity of CHF is linked to the expansion of specific monocyte subsets, and finally to investigate the relationship between monocyte subset relative frequencies, laboratory parameters of inflammation, and monocyte ACE expression. Thirty consecutive CHF patients and 26 healthy control subjects were evaluated for peripheral blood monocyte expression of CD14, CD16 and CD143 (ACE) by flow-cytometry, and for endothelial-derived soluble CD146 levels by ELISA. CD14 ++ CD16 + frequency was significantly higher in CHF patients than in Controls (%, median value and IQ) (12.3, 8.7-14.8 vs 5.9, 4.7-6.9, p < 0.05, CHF vs Controls), and it increased depending on how high NYHA class was, on worsening LV ejection fraction and on circulating pro-BNP values. Furthermore, it was associated with increasing creatinine and with decreasing GFR and albumin levels. Monocyte CD143 expression was significantly elevated in CHF patients as compared to Controls, and positively associated with CD14 ++ CD16 + levels. Frequencies of CD14 + CD16 + monocytes were significantly lower in CHF patients as compared to Controls, and negatively correlated with levels of soluble CD146 (r = -0.529; p 0.048).In conclusion, monocytic CD14 ++ CD16 + frequency and CD143 levels are increased and reflect disease status and progressive cardiac deterioration in CHF patients. The CD14 + CD16 + subset is depleted in CHF and is linked to endothelial damage in this group of patients. Although the question of whether differences in monocyte CD14CD16 expansion are causal or whether they represent a marker of HF progression which is potentially relevant for risk prediction remains unanswered, we believe that our data represent an important tool for exploring the role of selective inflammatory pathways in CHF progression.

Proinflammatory components are present in abdominal aortic aneurysm (AAA). Circulating monocytes display heterogeneity, and three subsets have been identified, based on the differential expression for CD14 and CD16 receptors: CD14+CD16-, classical, CD14+CD16+, intermediate and CD14dimCD16+, non-classical monocytes. Increased proinflammatory CD16+monocytes with high expression of CD143 are present in CKD patients. D-dimer is increased in AAA patients, and might contribute to the pro-inflammatory response associated to circulating monocytes. We aimed to investigate the frequency of CD14+CD16+, CD14dimCD16+monocytes and monocyte CD143 expression in AAA patients, and their relationship with D-dimer, eGFR and other inflammatory parameters. Blood from 74 AAA patients and 30 healthy controls was analyzed to determine the frequency of CD14+, CD16+, CD14dimCD16+monocytes and the monocyte CD143 expression by means of flow-cytometry. AAA patients had expanded CD16+SUPsets (CD14+CD16+: 7.66 ± 0.31% vs 5.42 ± 0.27%; CD14dimCD16+: 7.43 ± 0.48% vs 5.54 ± 0.38%, AAA vs controls, mean ± SE, both p<0.05). CD14+CD16+cells were associated to D-dimer and age, and to reduced eGFR. CD14dimCD16+cells were associated to uric acid, surface CD143, and reduced count of total leukocytes and neutrophils. Within AAA patients, the two CD16+supsets and the monocyte CD143 expression display different relationships with D-dimer, parameters of renal function and circulating biochemical and inflammatory biomarkers.

BACKGROUND AND PURPOSE5-fluorouracil (5FU) and its prodrug, capecitabine, can damage endothelial cells, whilst endothelial integrity is preserved by glucagon-like peptide 1 (GLP-1). Here, we studied the effect of 5FU on endothelial senescence and whether GLP-1 antagonizes it. EXPERIMENTAL APPROACHEA.hy926 cells were exposed to 5FU or sera from patients taking capecitabine, with or without pre-incubation with GLP-1. Senescence was identified by expression of senescence-associated β-galactosidase and p16INK4a and reduced cell proliferation. Soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1) and CD146 (marker of endothelial injury) were measured by ELISA before and at completion of capecitabine chemotherapy. RT-PCR, western blotting, functional experiments with signalling inhibitors and ERK1/2 silencing were performed to characterize 5FU-induced phenotype and elucidate the pathways underlying 5FU and GLP-1 activity. KEY RESULTSBoth 5FU and sera from capecitabine-treated patients stimulated endothelial cell senescence. 5FU-elicited senescence occurred via activation of p38 and JNK, and was associated with decreased eNOS and SIRT-1 levels. Furthermore, 5FU up-regulated VCAM1 and TYMP (encodes enzyme activating capecitabine and 5FU), and sVCAM-1 and CD146 concentrations were higher after than before capecitabine chemotherapy. A non-significant trend for higher ICAM1 levels was also observed. GLP-1 counteracted 5FU-initiated senescence and reduced eNOS and SIRT-1 expression, this protection being mediated by GLP-1 receptor, ERK1/2 and, possibly, PKA and PI3K. CONCLUSIONS AND IMPLICATIONS5FU causes endothelial cell senescence and dysfunction, which may contribute to its cardiovascular side effects. 5FU-triggered senescence was prevented by GLP-1, raising the possibility of using GLP-1 analogues and degradation inhibitors to treat 5FU and capecitabine vascular toxicity.

Senescence and apoptosis are two distinct cellular programs that are activated in response to a variety of stresses. Low or high doses of the same stressor, i.e., the anticancer drug doxorubicin, may either induce apoptosis or senescence, respectively, in cardiac muscle cells. We have demonstrated that PPARδ, a ligand-activated transcriptional factor that controls lipid metabolism, insulin sensitivity and inflammation, is also involved in the doxorubicin-induced senescence program. This occurs through its interference with the transcriptional repressor protein B cell lymphoma-6 (Bcl6). Low doses of doxorubicin increase the expression of PPARδ that sequesters Bcl6, thus preventing it from exerting its anti-senescent effects. We also found that L-165041, a specific PPARδ activator, is highly effective in protecting cardiomyocytes from doxorubicin-induced senescence through a Bcl6 related mechanism. In fact, L-165041 increases Bcl6 expression via p38, JNK and Akt activation, and at the same time it induces the release of Bcl6 from PPARδ, thereby enabling Bcl6 to bind to its target genes. L-165041 also prevented apoptosis induced by higher doses of doxorubicin. However, while experiments performed with siRNA analysis techniques very clearly showed the weight of Bcl6 in the cellular senescence program, no role was found for Bcl6 in the anti-apoptotic effects of L-165041, thus confirming that senescence and apoptosis are two very distinct stress response cellular programs. This study increases our understanding of the molecular mechanism of anthracycline cardiotoxicity and suggests a potential role for PPARδ agonists as cardioprotective agents.

ObjectiveThe uremic toxin Indoxyl-3-sulphate (IS), a ligand of Aryl hydrocarbon Receptor (AhR), raises in blood during early renal dysfunction as a consequence of tubular damage, which may be present even when eGFR is normal or only moderately reduced, and promotes cardiovascular damage and monocyte-macrophage activation. We previously found that patients with abdominal aortic aneurysms (AAAs) have higher CD14+CD16+ monocyte frequency and prevalence of moderate chronic kidney disease (CKD) than age-matched control subjects. Here we aimed to evaluate the IS levels in plasma from AAA patients and to investigate in vitro the effects of IS concentrations corresponding to mild-to-moderate CKD on monocyte polarization and macrophage differentiation.MethodsFree IS plasma levels, monocyte subsets and laboratory parameters were evaluated on blood from AAA patients and eGFR-matched controls. THP-1 monocytes, treated with IS 1, 10, 20 μM were evaluated for CD163 expression, AhR signaling and then induced to differentiate into macrophages by PMA. Their phenotype was evaluated both at the stage of semi-differentiated and fully differentiated macrophages. AAA and control sera were similarly used to treat THP-1 monocytes and the resulting macrophage phenotype was analyzed.ResultsIS plasma concentration correlated positively with CD14+CD16+ monocytes and was increased in AAA patients. In THP-1 cells, IS promoted CD163 expression and transition to macrophages with hallmarks of classical (IL-6, CCL2, COX2) and alternative phenotype (IL-10, PPARγ, TGF-β, TIMP-1), via AhR/Nrf2 activation. Analogously, AAA sera induced differentiation of macrophages with enhanced IL-6, MCP1, TGF-β, PPARγ and TIMP-1 expression.ConclusionIS skews monocyte differentiation toward low-inflammatory, profibrotic macrophages and may contribute to sustain chronic inflammation and maladaptive vascular remodeling.