Human neural progenitor cells display limited cytotoxicity and increased oligodendrogenesis during inflammation.
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Animals↗
Biomedical subjects
R De Maria
Publications and source records attributed to R De Maria.
The PU.1 transcription factor induces cyclin D2 expression in U937 cells.
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Cyclin D2↗
Chemotherapy resistance of glioblastoma stem cells.
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Animals↗
Enforced expression of KDR receptor promotes proliferation, survival and megakaryocytic differentiation of TF1 progenitor cell line.
Vascular endothelial growth factor (VEGF) receptor-2/kinase insert domain-containing receptor (KDR) is expressed in primitive hematopoietic cells, in megakaryocytes and platelets. In primitive hematopoiesis KDR mediates cell survival via autocrine VEGF, while its effect on cell growth and differentiation has not been elucidated. We induced enforced KDR expression in the granulocyte macrophage-colony-stimulating factor (GM-CSF)-dependent TF1 progenitor cell line (TF1-KDR), treated the cells with VEGF and analyzed their response. In GM-CSF-deprived cells, VEGF induces cell proliferation and protection against apoptosis, followed by enhanced expression of megakaryocytic (MK) markers. Combined with GM-CSF, VEGF induces a mild proliferative stimulus, followed by cell adherence, accumulation in G0/G1, massive MK differentiation and Fas-mediated apoptosis. Accordingly, we observed that MK-differentiating cells, derived from hematopoietic progenitors, produce VEGF, express KDR, inhibition of which reduces MK differentiation, indicating a key role of KDR in megakaryopoiesis. In conclusion, TF1-KDR cells provide a reliable model to investigate the biochemical and molecular mechanisms underlying hematopoietic progenitor proliferation, survival and MK differentiation.
Adult↗
Endogenous activation of metabotropic glutamate receptors supports the proliferation and survival of neural progenitor cells.
The use of neural progenitor cells (NPCs) is limited by the incomplete knowledge of the extracellular signals regulating their proliferation and survival. We report that cultured mouse NPCs express functional mGlu3 and mGlu5 metabotropic glutamate receptors. Pharmacological blockade of both receptors reduced NPC proliferation and survival, whereas activation of mGlu5 receptors substantially enhanced cell proliferation. Adult mice lacking mGlu5 receptors or treated with mGlu5 or mGlu3 receptor antagonists showed a dramatic reduction in the number of dividing neuroprogenitors present in the subventricular zone and in the dentate gyrus of the hippocampus. These data disclose a novel function of mGlu receptors and offer new potential strategies for the optimization of cell replacement therapy in neurodegenerative disorders.
Animals↗
Predictive value of EuroSCORE on long term outcome in cardiac surgery patients: a single institution study.
OBJECTIVES: To assess the value of the European system for cardiac operative risk evaluation (EuroSCORE), a validated model for prediction of in-hospital mortality after cardiac surgery, in predicting long term event-free survival. DESIGN AND SETTING: Single institution observational cohort study. PATIENTS: Adult patients (n = 1230) who underwent cardiac surgery between January 2000 and August 2002. RESULTS: Mean age was 65 (11) years and 32% were women. Type of surgery was isolated coronary artery bypass grafting in 62%, valve surgery in 23%, surgery on the thoracic aorta in 4%, and combined or other procedures in 11%. Mean EuroSCORE was 4.53 (3.16) (range 0-21); 366 were in the low (0-2), 442 in the medium (3-5), 288 in the high (6-8), and 134 in the very high risk group (> or = 9). Information on deaths or events leading to hospital admission after the index discharge was obtained from the Regional Health Database. Out of hospital deaths were identified through the National Death Index. In-hospital 30 day mortality was 2.8% (n = 34). During 2024 person-years of follow up, 44 of 1196 patients discharged alive (3.7%) died. By Cox multivariate analysis, EuroSCORE was the single best independent predictor of long term all cause mortality (hazard ratio (HR) 1.55, 95% confidence interval (CI) 1.03 to 2.34, p < 0.0001). In the time to first event analysis, 227 either died without previous events (n = 20, 9%) or were admitted to hospital for an event (n = 207, 91%). EuroSCORE (HR 1.60, 95% CI 1.36 to 1.89, p < 0.0001), the presence of > or = 2 co-morbidities versus one (HR 1.49, 95% CI 1.09 to 2.02, p < 0.0001), and > 96 hours' stay in the intensive care unit after surgery (HR 2.04, 95% CI 1.42 to 2.95, p = 0.0001) were independently associated with the combined end point of death or hospital admission after the index discharge. CONCLUSIONS: EuroSCORE and a prolonged intensive care stay after surgery are associated with long term event-free survival and can be used to tailor long term postoperative follow up and plan resource allocation for the cardiac surgical patient.
Aged↗
Relationship between B-type natriuretic peptide levels and ventilatory response during cardiopulmonary exercise test in patients with chronic heart failure.
AIM: Aim of the study was to evaluate if brain natriuretic peptide (BNP) levels, a cardiac neurohormone well correlated with prognosis in chronic heart failure (CHF), are associated with enhanced ventilatory response to exercise, in ambulatory patients with intermediate peak oxygen uptake (PVO2). METHODS: Resting BNP was measured in 129 consecutive stable CHF patients with mild to moderate heart failure (90% New York Heart Association (NYHA) class II or III) and intermediate (10-18 mL/kg/min) PVO2, assessed during cardiopulmonary exercise test. Mean (SD) left ventricular ejection fraction (EF) and pulmonary systolic pressure (PAP) were 41 +/- 3% and 47 +/- 14 mmHg, respectively. The enhanced ventilatory response to exercise (EVR) was assessed as a slope of the relation between minute ventilation and carbon dioxide production (VE/VCO2 slope) > 35. RESULTS: Thirty-three over 129 patients (26%) had EVR. Mean BNP plasma level was 394 +/- 347 pg/mL. A significant correlation between BNP and EVR (r = 0.310; p < 0.01), was observed. In the logistic multivariate model, a BNP plasma level > 100 pg/mL had an independent predictive value for EVR (95% IC 1.68 to 10.5, Odds Ratio 4.23, p = 0.02). We found a significant correlation between BNP and PAP (r = 0.390; p < 0.001), and between PAP and EVR (r = 0.511; p < 0.01). CONCLUSIONS: In CHF patients with intermediate PVO2, plasma BNP is clearly related to the enhanced ventilatory response to exercise. In this subset, BNP levels could represent an effective alternative tool for the clinical assessment in patients with unreliable cardiopulmonary exercise test.
Aged↗
Activation of Fas receptor is required for the increased formation of the disialoganglioside GD3 in cultured cerebellar granule cells committed to apoptotic death.
Apoptosis was induced in cultured cerebellar granule cells by lowering extracellular K+ concentrations (usually from 25 to 10 mM). The apoptotic phenotype was preceded by an early and transient increase in the intracellular levels of the disialoganglioside, GD3, which behaves as a putative pro-apoptotic factor. We examined whether activation of Fas receptor mediates the increase in GD3 formation in granule cells committed to die. Degenerating granule cells showed increased expression of both Fas receptor and its ligand (Fas-L), at times that coincided with the increase in GD3 levels and the induction of GD3 synthase mRNA. Addition of neutralizing anti-Fas-L antibodies reduced the extent of 'low-K+'-induced apoptosis and abolished the increase in GD3 levels and GD3 synthase mRNA. Similar reductions were observed in cultures prepared from gld or lpr mice, which harbor loss-of-function mutations of Fas-L and Fas receptor, respectively. In addition, exogenous application of soluble Fas-L further enhanced both the increase in GD3 formation and cell death in cultured granule cells switched from 25 into 10 mM K+. We conclude that activation of Fas receptor is entirely responsible for the increase in GD3 levels and contributes to the development of apoptosis by trophic deprivation in cultured cerebellar granule cells.
Animals↗
Involvement of interferon regulatory factor-1 in monocyte CD95 expression and CD95-mediated apoptosis.
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Apoptosis↗
Control of erythroid cell production via caspase-mediated cleavage of transcription factor SCL/Tal-1.
SCL/Tal-1 is a helix-loop-helix (HLH) transcription factor required for blood cell development, whose abnormal expression is responsible for induction of T-cell acute lymphoblastic leukemia. We show here that SCL/Tal-1 is a key target of caspases in developing erythroblasts. SCL/Tal-1 degradation occurred rapidly after caspase activation and preceded the cleavage of the major erythroid transcription factor GATA-1. Expression of a caspase-resistant SCL/Tal-1 in erythroid progenitors was able to prevent amplification of caspase activation, GATA-1 degradation and impaired erythropoiesis induced by growth factor deprivation or death receptor triggering. The potent proerythropoietic activity of uncleavable SCL/Tal-1 was clearly evident in the absence of erythropoietin, a condition that did not allow survival of normal erythroid cells or expansion of erythroblasts expressing caspase-resistant GATA-1. In the absence of erythropoietin, cells expressing caspase-resistant SCL/Tal-1 maintain high levels of Bcl-X(L), which inhibits amplification of the caspase cascade and mediates protection from apoptosis. Thus, SCL/TAL-1 is a survival factor for erythroid cells, whereas caspase-mediated cleavage of SCL/Tal-1 results in amplification of caspase activation, GATA-1 degradation and impaired erythropoiesis.
Amino Acid Chloromethyl Ketones↗
An early increase in the disialoganglioside GD3 contributes to the development of neuronal apoptosis in culture.
We induced apoptosis in primary cultures of cerebellar granule neurons by switching the growing medium into a medium containing lower concentrations of K(+) (5 or 10 mM instead of 25 mM) or, alternatively, by addition of staurosporine. The apoptotic phenotype was always preceded by an early increase in the intracellular levels of the disialoganglioside GD3, which peaked at 2-6 h and returned back to normal at 12 h. GD3 synthase, the enzyme that forms GD3 from the monosialoganglioside GM3, was also induced at early times after the induction of apoptosis in granule cells. Immunofluorescent staining showed that GD3 increased in neuronal cell bodies and neurites, but was never localized in cell nuclei. In cultures switched into a low K(+)-containing medium, exogenously applied GD3, but not the disialoganglioside GD1a, accelerated the development of neuronal apoptosis. In contrast, the antisense-induced knock-down of GD3 synthase was protective against granule cell death induced by lowering extracellular K(+) from 25 to 10 - but not 5 - mM. These results demonstrate that an early and transient increase in GD3 synthesis is one of the factors that contribute to the induction of neuronal apoptosis in culture.
Animals↗
Mucopolysaccharidosis VI in a Siamese/short-haired European cat.
A 3-year-old Siamese/short-haired European cat was referred for clinical disease characterized by dwarfism, facial dysmorphia, paralysis, small and curled ears, corneal clouding and large areas of alopecia. X-ray examination showed multiple bone dysplasia. On the basis of clinical features a form of mucopolysaccharidosis was suspected. The cat, killed at the owner's request, presented several severe skeletal deformities such as long caudal limbs, enlarged thorax with sunken breastbone, vertebral ankylosis in many spinal segments and visceral involvement. Histologically, the cat showed diffuse vacuolization and enlargement of cells in cartilage, bone and visceral organs. Ultrastructurally, membrane-bound vacuoles were filled with fibrillar and fluffy-material or concentrically whorled lamellae. Arylsulphatase B activity was 3.24 nm/mg/h in the affected cat and 30.6 in a normal age-matched control (NC). The L-iduronidase activity was slightly increased. Quantitation of total glycosaminoglycans (GAGs) revealed a 4.5-fold increase in the affected cat as compared with NC, while electrophoretic run of specific GAGs [chondroitin sulphate (CA); hyaluronan (HA); heparan sulphate (HS); dermatan sulphate (DS); keratan sulphate (KS)] performed on a cellulose acetate sheet, showed a striking increase in the DS band. On densitometric analysis of the electrophoretic run stained with Alcian Blue 8GX, the absorption of DS was eight-fold increased as compared with NC. The clinical and morphological features, and the biochemical findings, were consistent with the diagnosis of feline mucopolysaccharidosis VI.
Animals↗
Fas-FasL in Hashimoto's thyroiditis.
Hashimoto's thyroiditis is a common chronic autoimmune disease characterized by the loss of thyroid follicular cells (thyrocytes) that are gradually replaced by lymphocytic infiltration and diffuse fibrosis. These morphological findings suggested that autoreactive T-cell clones were responsible for thyrocyte destruction and hypothyroidism through effector-target cytotoxic recognition. Later, autonomous interaction between thyrocyte Fas and FasL has been proposed as a major mechanism of thyrocyte depletion in Hashimoto's thyroiditis. Here, we analyze the possible role of Fas and FasL in the pathogenesis of Hashimoto's thyroiditis. We suggest that the Fas-FasL system dictates the outcome of the autoimmune response by acting on both immune and target cells.
Apoptosis↗
Resting echocardiography and quantitative dipyridamole technetium-99m sestamibi tomography in the identification of cardiac allograft vasculopathy and the prediction of long-term prognosis after heart transplantation.
AIMS: To evaluate the accuracy of echocardiography in conjunction with quantitative high-dose dipyridamole technetium-99m sestamibi tomography (SPECT) in detecting coronary allograft vasculopathy. METHODS AND RESULTS: Seventy-eight consecutive heart transplant recipients underwent echocardiography while at rest and high-dose dipyridamole SPECT within 48 h of a yearly angiogram. Resting wall motion abnormalities were considered significant if present in two or more segments. SPECT was considered abnormal in the presence of reversible/fixed defects. The coronary angiogram was normal in 53, showed non-significant coronary allograft vasculopathy in 13 and significant (> or = 50% stenosis) coronary allograft vasculopathy in 12 cases. Resting wall motion abnormalities were observed in nine cases and perfusion defects in 20. Echocardiography and SPECT were concordant in 59 cases (five positive and 54 negative); in these, accuracy was 100% for significant coronary allograft vasculopathy and 83% for any coronary allograft vasculopathy. Over 6.5+/-2 years, 17 patients suffered coronary allograft vasculopathy-related events, including death in six and retransplantation in three. Resting wall motion abnormalities, SPECT perfusion defects and angiographic coronary allograft vasculopathy were significant predictors of cardiac events. CONCLUSION: Normal resting wall motion at echocardiography coupled to normal stress myocardial perfusion, rules out the presence of significant coronary allograft vasculopathy in many heart transplant recipients. Conversely, resting wall motion abnormalities and perfusion defects strongly predict cardiac events. Therefore, a strategy which reserves angiography for patients with resting wall motion abnormalities and/or perfusion defects may be safe and cost-effective.
Adolescent↗
Metoprolol-induced functional benefit in dilated cardiomyopathy is sustained over four years and favorably influences outcome.
BACKGROUND: Beta-blockers improve survival and ventricular function in patients with heart failure. We evaluated the long-term persistence of metoprolol-induced improvement and its impact on prognosis in idiopathic dilated cardiomyopathy. METHODS: Two hundred and four of 586 patients enrolled in a registry on the natural history of idiopathic dilated cardiomyopathy survived 4 years without transplantation; 98 of them were on standard heart failure treatment, whereas 106 took metoprolol in addition. We analyzed the effects of treatment using beta-blockers in terms of changes in left ventricular ejection fraction (LVEF), NYHA functional class and left ventricular end-diastolic diameter index (LVEDDI) after 1, 2 and 4 follow-up years in order to elaborate an improvement score that was related to the subsequent outcome over 60 months after the 4-year follow-up visit. RESULTS: Greater LVEF increases and NYHA functional class and LVEDDI decreases were observed in patients submitted to metoprolol vs standard treatment at all stages of follow-up. Changes (delta vs baseline) for LVEF (p = 0.02), NYHA functional class (p = 0.0001) and LVEDDI (p = 0.004) were maximal during the first year (10 +/- 11 vs 6 +/- 12 units, -0.72 +/- 0.77 vs -0.23 +/- 0.81, -3.5 +/- 5 vs -1.6 +/- 3.5 mm), persisted at 2 (12 +/- 12 vs 8 +/- 12 units, -0.80 +/- 0.70 vs -0.37 +/- 0.87, -4.2 +/- 5 vs -2.3 +/- 4 mm) but showed a trend to decline at 4 years (11 +/- 12 vs 8 +/- 13 units, -0.54 +/- 0.90 vs -0.24 +/- 0.91, -4.3 +/- 5 vs -2.3 +/- 5 mm) of follow-up. Improvement at 4 years was associated with a better transplant-free survival (81 vs 52%, p = 0.0005, odds ratio 0.36, 95% confidence interval 0.18 to 0.74). CONCLUSIONS: In idiopathic dilated cardiomyopathy, the more significant improvement in symptoms and left ventricular function and size, that is observed following treatment using metoprolol, translates into a better outcome. These benefits peak within the first 2 years of start of treatment but may begin to fade thereafter.
Adrenergic beta-Antagonists↗
Alcohol abuse and dilated cardiomyopathy in men.
Excessive ethanol intake is reported in 3% to 40% of patients with idiopathic dilated cardiomyopathy (IDC). In the prevasodilator era, the prognosis was reportedly better in alcoholic than in IDC patients, an advantage limited to abstinent patients. No large series of patients systematically treated with angiotensin-converting enzyme inhibitors has since been described. We analyzed long-term outcome according to alcohol abuse in male patients with IDC. Among 338 men who had been prospectively enrolled in a multicenter registry, 79 (23%) were defined as alcohol abusers and further classified at follow-up as having stopped (AAS) or continued (AAC) abuse. AAC subjects at enrollment reported a higher daily alcohol intake than AAS subjects (178 +/- 113 vs 127 +/- 54 g/day, p = 0.012). During a mean of 59 +/- 35 months, 102 patients died and 45 underwent transplantation. Seven-year transplant-free survival was significantly lower in alcohol abusers (41%) than in patients with IDC (53%, p = 0.026), and significantly lower in AAC subjects (27%) than in either patients with IDC or AAS (45%) (p = 0. 018). Although IDC patients had beneficial changes in left ventricular function at follow-up, only AAS patients had significant improvement in ejection fraction. In this large series of patients treated with angiotensin-converting enzyme inhibitors and prospectively followed up, excessive alcohol intake was found in about one fourth of cases and persistent alcohol abuse correlated with a worse prognosis and function at follow-up.
Adult↗
CD95/CD95L interactions and their role in autoimmunity.
CD95 (Fas/Apo-1) is a broadly expressed death receptor involved in a variety of physiological and pathological apoptotic processes. Since its discovery, defects in CD95/CD95L system have been proposed as major pathogenic factors responsible for impaired immunological tolerance to self antigens and autoimmunity. Later, analysis of altered sensitivity to CD95-induced apoptosis in cells targeted by the immune response has revealed an unexpected role for CD95 and CD95L in organ-specific autoimmunity. CD95 has been shown to be expressed and functional in virtually all cell types that are target of the organ-specific autoimmune response. Here we review some of the major findings concerning the role of CD95 in autoimmunity, in dysfunctions due to increased or decreased CD95-induced apoptosis.
Animals↗
Control of target cell survival in thyroid autoimmunity by T helper cytokines via regulation of apoptotic proteins.
After autoimmune inflammation, interactions between CD95 and its ligand (CD95L) mediate thyrocyte destruction in Hashimoto's thyroiditis (HT). Conversely, thyroid autoimmune processes that lead to Graves' disease (GD) result in autoantibody-mediated thyrotropin receptor stimulation without thyrocyte depletion. We found that GD thyrocytes expressed CD95 and CD95L in a similar manner to HT thyrocytes, but did not undergo CD95-induced apoptosis either in vivo or in vitro. This pattern was due to the differential production of TH1 and TH2 cytokines. Interferon gamma promoted caspase up-regulation and CD95-induced apoptosis in HT thyrocytes, whereas interleukin 4 and interleukin 10 protected GD thyrocytes by potent up-regulation of cFLIP and Bcl-xL, which prevented CD95-induced apoptosis in sensitized thyrocytes. Thus, modulation of apoptosis-related proteins by TH1 and TH2 cytokines controls thyrocyte survival in thyroid autoimmunity.
Adult↗