Chiara Barisione

Doxorubicin induces senescence or apoptosis in rat neonatal cardiomyocytes by regulating the expression levels of the telomere binding factors 1 and 2

Low or high doses of doxorubicin induce either senescence or apoptosis, respectively, in cardiomyocytes. 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-beta-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>4N 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.

Adipose tissue immune response: novel triggers and consequences for chronic inflammatory conditions.

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.

CD14CD16 Monocyte Subset Levels in Heart Failure Patients

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++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.

Resveratrol counteracts systemic and local inflammation involved in early abdominal aortic aneurysm development

BACKGROUND Monocyte activation, macrophage infiltration, vascular oxidative stress and matrix proteolysis are inflammatory key steps contributing to abdominal aortic aneurysm (AAA) development. A phenotypical and functional heterogeneity is recognizable in monocytes by the differential expression of surface molecules: CD62L- subset corresponds to activated monocytes, while CD143/ACE surface expression increases during their differentiation into macrophages. In this work, Resveratrol, which is an antioxidant polyphenol with vasoprotective properties, has been evaluated for its potential to limit aneurysm development and monocyte-dependent inflammatory response in a model of elastase-induced AAA. METHODS Male Sprague-Dawley rats received Resveratrol (10 mg/kg/die) (Rsv group, n=15) or vehicle (ethanol) alone (Et-OH group, n=15) continuously from 7 d before until 14 d after the AAA induction with elastase; five littermates were used as untreated control group (Ctr group, n=5). At the end of treatment, CD143 and CD62L monocyte expression was analyzed by flow cytometry, serum antioxidant capacity was evaluated using the TRAP method and circulating TNFα, and MMP-9 were measured with ELISA and gel zymography, respectively. Aortas were subjected to histology and immunohistochemistry for morphological analysis, macrophage infiltration, and MMP-9, TNFα, and VEGF expression. RESULTS Resveratrol counteracted the CD62L-monocyte subset expansion, CD143 monocyte expression, and circulating levels of MMP-9 activity and TNFα associated to AAA induction. Similarly, treatment with Resveratrol significantly attenuated AAA expansion, vessel wall macrophage infiltration and MMP-9, VEGF, and TNFα expression, compared with AAA from Et-OH group. CONCLUSIONS Resveratrol limited the monocyte-dependent inflammatory response, macrophage differentiation and aortic lumen enlargement in elastase-induced AAA. These data suggest that Resveratrol might be tested in selected patients with small AAA to modulate the early systemic and local inflammatory response associated to AAA progression.

p38 MAPK and JNK Antagonistically Control Senescence and Cytoplasmic p16INK4A Expression in Doxorubicin-Treated Endothelial Progenitor Cells

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.

Postprandial serum induces apoptosis in endothelial cells: Role of polymorphonuclear-derived myeloperoxidase and metalloproteinase-9 activity

Postprandial state is a pro-inflammatory condition associated with a transient impairment of endothelial function. Recent evidence suggests that myeloperoxidase (MPO) and matrix metalloproteinase-9 (MMP-9) are involved in the pathogenesis of inflammatory vascular diseases such as atherosclerosis. The present study was carried out to investigate whether a fat meal induces polymorphonuclear (PMN) activation and increases the plasma activity of MPO and MMP-9 and whether postprandial serum exerts pro-apoptotic effects on endothelial cells. Fifteen healthy young men underwent a high-fat challenge containing 60g butter. Blood samples were drawn before, and 1, 2, and 4h after the meal. Leukocyte reactive oxygen species (ROS) production, plasma MPO and MMP-9 activity, endothelial-derived soluble CD146 levels, and advanced oxidation protein product (AOPP) levels were determined. Human umbilical vein endothelial cells (HUVECs) were treated with human sera to evaluate mitochondrial membrane potential, ROS production, annexin PI staining, and caspase-3 activity. Triglycerides, ROS production, MPO activity, AOPP levels, pro-MMP-9 zymographic activity, and soluble CD146 levels significantly increased during the 4h after the test meal. Postprandial serum significantly decreased the mitochondrial membrane potential, and increased the rate of ROS production, the percentage of annexin-positive HUVECs, and caspase-3 activity. A strong relationship was observed between postprandial increase in PMN-derived MPO and pro-MMP-9 activity, and the increased rate of apoptosis of endothelial cells exposed to postprandial serum. Data show that postprandial serum exerts pro-apoptotic effects on endothelial cells. The close relationships between markers of endothelial cell apoptosis and MPO and pro-MMP-9 activity suggest that the latter may contribute to the development of fat meal induced endothelial damage.

Adiponectin and Plant-Derived Mammalian Adiponectin Homolog Exert a Protective Effect in Murine Colitis

BackgroundHypoadiponectinemia has been associated with states of chronic inflammation in humans. Mesenteric fat hypertrophy and low adiponectin have been described in patients with Crohn’s disease. We investigated whether adiponectin and the plant-derived homolog, osmotin, are beneficial in a murine model of colitis.MethodsC57BL/6 mice were injected (i.v.) with an adenoviral construct encoding the full-length murine adiponectin gene (AN+DSS) or a reporter—LacZ (Ctr and V+DSS groups) prior to DSS colitis protocol. In another experiment, mice with DSS colitis received either osmotin (Osm+DSS) or saline (DSS) via osmotic pumps. Disease progression and severity were evaluated using body weight, stool consistency, rectal bleeding, colon lengths, and histology. In vitro experiments were carried out in bone marrow-derived dendritic cells.ResultsMice overexpressing adiponectin had lower expression of proinflammatory cytokines (TNF, IL-1β), adipokines (angiotensin, osteopontin), and cellular stress and apoptosis markers. These mice had higher levels of IL-10, alternative macrophage marker, arginase 1, and leukoprotease inhibitor. The plant adiponectin homolog osmotin similarly improved colitis outcome and induced robust IL-10 secretion. LPS induced a state of adiponectin resistance in dendritic cells that was reversed by treatment with PPARγ agonist and retinoic acid.ConclusionAdiponectin exerted protective effects during murine DSS colitis. It had a broad activity that encompassed cytokines, chemotactic factors as well as processes that assure cell viability during stressful conditions. Reducing adiponectin resistance or using plant-derived adiponectin homologs may become therapeutic options in inflammatory bowel disease.

Testosterone Antagonizes Doxorubicin-Induced Senescence of Cardiomyocytes

Background Chronic cardiotoxicity is less common in male than in female patients receiving doxorubicin and other anthracyclines at puberty and adolescence. We hypothesized that this sex difference might be secondary to distinct activities of sex hormones on cardiomyocyte senescence, which is thought to be central to the development of long‐term anthracycline cardiomyopathy. Methods and Results H9c2 cells and neonatal mouse cardiomyocytes were exposed to doxorubicin with or without prior incubation with testosterone or 17β‐estradiol, the main androgen and estrogen, respectively. Testosterone, but not 17β‐estradiol, counteracted doxorubicin‐elicited senescence. Downregulation of telomere binding factor 2, which has been pinpointed previously as being pivotal to doxorubicin‐induced senescence, was also prevented by testosterone, as were p53 phosphorylation and accumulation. Pretreatment with the androgen receptor antagonist flutamide, the phosphatidylinositol 3 kinase inhibitor LY294002, and the nitric oxide synthase inhibitor L‐NG‐nitroarginine methyl ester abrogated the reduction in senescence and the normalization of telomere binding factor 2 levels attained by testosterone. Consistently, testosterone enhanced the phosphorylation of AKT and nitric oxide synthase 3. In H9c2 cells, doxorubicin‐stimulated senescence was still observed up to 21 days after treatment and increased further when cells were rechallenged with doxorubicin 14 days after the first exposure to mimic the schedule of anthracycline‐containing chemotherapy. Remarkably, these effects were also inhibited by testosterone. Conclusions Testosterone protects cardiomyocytes against senescence caused by doxorubicin at least in part by modulating telomere binding factor 2 via a pathway involving the androgen receptor, phosphatidylinositol 3 kinase, AKT, and nitric oxide synthase 3. This is a potential mechanism by which pubescent and adolescent boys are less prone to chronic anthracycline cardiotoxicity than girls.

CD16 + monocyte subsets are increased in large abdominal aortic aneurysms and are differentially related with circulating and cell-associated biochemical and inflammatory biomarkers

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 CD14dim CD16+, 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+, CD14dim CD16+ 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+, CD14dim CD16+ 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%; CD14dim CD16+: 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. CD14dim CD16+ 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.

Increased neutrophil lifespan in patients with congestive heart failure

Congestive heart failure (CHF) can be thought of as a state of chronic immune activation. Polymorphonuclear neutrophil (PMN) apoptosis is one of the mechanisms responsible for the resolution of inflammation. A reduced PMN apoptotic rate in CHF patients may generate a persistent inflammatory response and hence mediate tissue damage in this group of patients. We aimed to measure levels of spontaneous apoptosis of circulating PMNs in CHF patients and in controls, and to examine whether NYHA class, left ventricular ejection fraction (LV‐EF), and laboratory parameters of inflammation, endothelial damage, and of liver and renal function, could predict the rate of PMN apoptosis in CHF patients.