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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.

The mechanism by which different doses of doxorubicin may induce different stress-response cellular programs is not well understood. A recent study showed that the level of telomere dysfunction may induce senescence or apoptosis. We investigated the pathways to both apoptosis and senescence in neonatal rat cardiomyocytes and in H9c2 cells exposed to a single pulsed incubation with low or high doses of doxorubicin. High-dose doxorubicin strongly reduces TRF2 expression while enhancing TRF1 expression, and it determines early apoptosis. Low-dose doxorubicin induces downregulation of both TRF2 and TRF1, and it also increases the senescence-associated-␤-galactosidase activity, downregulates the checkpoint kinase Chk2, induces chromosomal abnormalities, and alters the cell cycle. The involvement of TRF1 and TRF2 with apoptosis and senescence was assessed by short interfering RNA interference. The cells maintain telomere dysfunction and a senescent phenotype over time and undergo late death. The increase in the phase Ͼ4N and the presence of micronuclei and anaphase bridges indicate that cells die by mitotic catastrophe. p38 modulates TRF2 expression, whereas JNK and cytoplasmic p53 regulate TRF1. Pretreatment with specific inhibitors of MAPKs and p53 may either attenuate the damage induced by doxorubicin or shift the cellular response to stress from senescence to apoptosis. In conclusion, various doses of doxorubicin induce differential regulation of TRF1 and TRF2 through p53 and MAPK, which is responsible for inducing either early apoptosis or senescence and late death due to mitotic catastrophe. p53; mitogen-activated protein kinases; anthracyclines THE CLINICAL USE OF ANTHRACYCLINES in anti-cancer treatment is limited by their adverse cardiotoxic effects, which include cardiomyopathy and heart failure (22). At high doses, cardiotoxicity often occurs within a few months, whereas low doses rarely cause deterioration of ventricular function in the first year after therapy (58). However, there is now increasing evidence that, several years after therapy, one of three patients treated with low-dose anthracyclines develops hypokinetic cardiomyopathy (21). A number of mechanisms have been proposed to explain anthracycline cardiotoxicity. Although the most accredited hypothesis states that anthracyclines induce myocyte loss through oxidative stress and apoptotic cell death (3, 48), there is controversy whether apoptosis contributes to late onset cardiotoxicity induced by low doses of doxorubicin (4). Maejima et al. (34) recently showed that when cultured neonatal rat cardiomyocytes are exposed to low concentrations of doxorubicin, the cells do not enter apoptotic program but exhibit a senescence-like phenotype. The hallmark of cellular senescence is the cell cycle arrest that is accompanied by important changes in many aspects of cell morphology (20,38). Senescence is the result of changes in the expression of many proteins that regulates cell cycle, cytoskeletal function, and cellular architecture and causes impairment o...

Patients treated with low-dose anthracyclines often show late onset cardiotoxicity. Recent studies suggest that this form of cardiotoxicity is the result of a progenitor cell disease. In this study we demonstrate that Cord Blood Endothelial Progenitor Cells (EPCs) exposed to low, sub-apoptotic doses of doxorubicin show a senescence phenotype characterized by increased SA-b-gal activity, decreased TRF2 and chromosomal abnormalities, enlarged cell shape, and disarrangement of F-actin stress fibers accompanied by impaired migratory ability. P16 INK4A localizes in the cytoplasm of doxorubicin-induced senescent EPCs and not in the nucleus as is the case in EPCs rendered senescent by different stimuli. This localization together with the presence of an arrest in G2, and not at the G1 phase boundary, which is what usually occurs in response to the cell cycle regulatory activity of p16INK4A, suggests that doxorubicin-induced p16 INK4A does not regulate the cell cycle, even though its increase is closely associated with senescence. The effects of doxorubicin are the result of the activation of MAPKs p38 and JNK which act antagonistically. JNK attenuates the senescence, p16 INK4A expression and cytoskeleton remodeling that are induced by activated p38. We also found that conditioned medium from doxorubicin-induced senescent cardiomyocytes does not attract untreated EPCs, unlike conditioned medium from apoptotic cardiomyocytes which has a strong chemoattractant capacity. In conclusion, this study provides a better understanding of the senescence of doxorubicin-treated EPCs, which may be helpful in preventing and treating late onset cardiotoxicity.

Regardless of the clinical phase of heart failure, elevated levels of activity and of circulating metalloproteinase protein levels suggest the presence of persistent extracellular remodeling in patients with heart failure.

Myocarditis is a rare but serious adverse event of immune checkpoint blockade with nivolumab, which needs to be recognized as soon as possible. This article suggests that troponin, a user-friendly biomarker of myocardial cytotoxicity, might be useful for early detection of immune-mediated myocarditis. However, because troponin abnormalities might also be related to a number of conditions capable of causing myocardial oxygen demand-supply mismatch, a careful cardiac assessment should be performed in non-small cell lung cancer patients in order to properly interpret any troponin increase. According to the available evidence, monitoring troponin during the first weeks of treatment can be considered reasonable.

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.