Cephalostatin 1 inactivates Bcl-2 by hyperphosphorylation independent of M-phase arrest and DNA damage

Cephalostatin 1 is a marine product that induces a novel cytochrome c-independent apoptotic pathway in Jurkat leukemia T cells (Cancer Res 63:8869-8876, 2003). Here, we show that overexpression of the antiapoptotic protein Bcl-2 protects cells only partially against cephalostatin 1-induced apoptosis. The mechanism of Bcl-2 inactivation by cephalostatin 1 is based on hyperphosphorylation of Bcl-2 on Thr69 and Ser87 because Jurkat cells overexpressing a Bcl-2 protein with mutations on both phosphorylation sites were completely protected against cephalostatin 1. In search of the kinase responsible for Bcl-2 phosphorylation, c-Jun NH2-terminal kinase (JNK) was found to be activated by cephalostatin 1. Reduction of Bcl-2 phosphorylation by the specific JNK inhibitor (anthra(1,3-cd)pyrazol-6(2H)-one) SP600125 suggested a crucial role for JNK in this process. JNK activation was not a consequence of DNA damage, a known stimulus of JNK, because cephalostatin 1 did not induce DNA lesions as shown by the comet assay. Arrest in M-phase is also demonstrated to be associated with JNK activation. However, cephalostatin 1 does not evoke an arrest in M-phase as shown by flow cytometry. Together, cephalostatin 1 is shown to induce JNK activation with subsequent Bcl-2 phosphorylation and inactivation. Reported triggers, such as the induction of an M-phase arrest or DNA damage are not involved in this process, suggesting a novel mechanism for cephalostatin 1-mediated Bcl-2 hyperphosphorylation.     

Resveratrol inhibits angiotensin II- and epidermal growth factor-mediated Akt activation: role of Gab1 and Shp2

trans-Resveratrol (RV), a polyphenolic stilbene derivative found in grape skin and other food products, has been proposed to exert beneficial effects in cardiovascular disease. Our group has shown previously that RV inhibits angiotensin II (Ang II)-induced Akt activation and, consequently, vascular smooth muscle cell (VSMC) hypertrophy. In this work, to identify the molecular target of RV, we investigated the impact of RV on early signaling cascades in rat aortic VSMCs triggered by Ang II and epidermal growth factor (EGF). We show that RV does not influence Ang II-mediated transactivation of EGF-receptor but potently inhibits EGF-induced phosphorylation of Akt kinase, suggesting that RV acts downstream of EGF-receptor transactivation in VSMCs. Recent evidence indicates that the adapter molecule Gab1, together with the protein tyrosine phosphatase Shp2, is critically involved in regulating the strength and duration of phosphatidylinositol-3-kinase (PI3K) and Akt activation upon EGF stimulation in fibroblasts. Our results show that stimulation of VSMCs with EGF as well as Ang II leads to a rapid tyrosine phosphorylation of Gab1 and its association with the p85 subunit of PI3K. RV attenuates these processes. Experiments performed in Shp2-deficient fibroblasts revealed that RV does not inhibit EGF-stimulated Akt activation in these cells, suggesting that Shp2 is necessary for the inhibitory effect of RV on the PI3K/Akt pathway. Furthermore, RV treatment activates Shp2. We therefore propose that RV blocks Akt activation in Ang II- and EGF-stimulated VSMCs by activating Shp2, thus preventing interaction between Gab1 and PI3K that is necessary for further signal transduction.     

Alpha-synuclein protein levels are increased in alcoholic patients and are linked to craving

BACKGROUND: Alpha synuclein has been found to be increased in dopamine neurones of cocaine abusers and in rats whose alcohol preference is inbred. Furthermore, increased alpha-synuclein messenger RNA expression has been linked to craving in patients with alcoholism. The aim of the current study was to investigate whether protein levels of alpha synuclein in alcoholics are changed and possibly influence alcohol craving. METHODS: The alpha-synuclein protein expression level was measured by enzyme-linked immunosorbent assay in the serum of 49 male alcoholics and 50 nondrinking healthy controls. Alcohol craving was assessed by the Obsessive-Compulsive Drinking Scale total score, including subscales for obsessive and compulsive craving. RESULTS: Alpha-synuclein protein expression in patients with alcoholism (14.33 ng/ml; SD, 13.01 ng/ml) was significantly higher (t test, T = 3.66, p < 0.0001) when compared with that of healthy controls (5.92 ng/ml; SD, 9.72 ng/ml). Using a multivariate analysis, all craving scores (Obsessive-Compulsive Drinking Scale total score and obsessive and compulsive subscale scores) in alcoholics were significantly associated with their alpha-synuclein protein levels (multiple linear regression, p < 0.014). CONCLUSIONS: To our knowledge, this is the first study evaluating alpha-synuclein protein expression in alcoholics. The current study provides further evidence of altered alpha-synuclein levels in patients with alcoholism and their linkage to alcohol craving. Because alpha synuclein is involved in the modulation of dopaminergic neurotransmission, these results deliver further pathophysiological explanations of craving mechanisms.     

Peripheral dendritic cell chimerism in allogeneic hematopoietic stem cell recipients

BACKGROUND: Relapse and graft-versus-host disease (GVHD) represent major causes of morbidity and mortality following allogeneic hematopoietic stem cell transplantation (HSCT). Although leukocyte and T-cell chimerism analyses are performed routinely suggesting a predictive value on the patients outcome, little is known about chimerism of dendritic cells (DC) representing strong initiators of immune responses. METHODS: In this prospective study, peripheral DC1 (CD11c+) and DC2 (CD123+) chimerism was determined in hematopoetic stem cell recipients. DCs were isolated from peripheral blood by fluorescence activated cell sorting. Chimerism analyses were performed by fluorescent in situ hybridization or by polymerase chain reaction-based typing of short tandem repeats. RESULTS: At time of engraftment, DC chimerism analyses showed complete chimerism in 76.3% (DC1)/79.5% (DC2), mixed chimerism (MC) in 21.0% (DC1)/17.9% (DC2) and no chimerism in 2.7% (DC1)/2.6% (DC2) of the patients. Peripheral DC chimerism had no significant effect on relapse-free or overall survival. Although acute GVHD was observed more often in patients with MC for DC1/DC2 and chronic GVHD occurred more often in patients with MC for DC2, there was no statistically significant correlation. CONCLUSIONS: Although DCs as antigen presenting cells are supposed to have an impact on the induction of GVHD, there was no significant correlation between incidence of GVHD and DC chimerism after HSCT.     

Severe hypoglycaemia,metabolic control and diabetes management in children with type 1 diabetes in the decade after the Diabetes Control and Complications Trial – a large-scale multicentre study

Hypoglycaemia is frequently the limiting factor in achieving optimal glycaemic control. Therefore, insulin therapy, the incidence of hypoglycaemia, and glycaemic control were investigated in 6309 unselected children with type 1 diabetes in a large-scale multicentre study. Using standardised computer-based documentation, the incidence of severe hypoglycaemia, HbA1 _c levels, insulin regimen, diabetes duration, and the number of patients attending a treatment centre were investigated for the age groups 0-<5 years ( n =782), 5-<7 years ( n =1053), and 7-<9 years ( n =4474). The average HbA1 _c level was 7.6% (no significant difference between age groups). Young children had more severe hypoglycaemic events (31.2/100 patient years) as compared to older children (19.7; 21.7/100 patient years, P <0.05) independent of the treatment regimen. Our data suggest that diabetes centres treating less than 50 patients per year have a higher incidence of hypoglycaemia in 0-<5-year-old children (43.0/100 patient years) as compared to larger centres (24.1/100 patient years; P <0.0001). Significant predictors of hypoglycaemia were younger age ( P <0.0001), longer diabetes duration ( P <0.0001), higher insulin dose/kg per day ( P <0.0001), injection regimen ( P <0.0005), and centre experience ( P <0.05). Conclusion:Despite modern treatment, young children have an elevated risk for developing severe hypoglycaemia compared to older children, especially when treated at smaller diabetes centres. The therapeutic goal of carefully regulating metabolic control without developing hypoglycaemia has still not been achieved. Further advances in diabetic treatment may result from giving more attention to hypoglycaemia in young children.On behalf of the German Initiative on Quality Control in Paediatric Diabetology.     

Vaccine strategies of meningococcal disease: results of a 10-year population-based study

Invasive meningococcal disease (IMD) is an important cause of morbidity and mortality in children and adults. This study was conducted to determine a possible increase in IMD in recent years with special interest focused on serogroup C disease. From January 1st 1993 to December 31st 2002, IMD was studied in one million residents of Austria. We used active, population-based surveillance data from the Office of Public Health. A total of 126 patients with positive blood and/or cerebrospinal fluid culture or positive swabs for Neisseria meningitidis were studied. The median age of all patients was 9.5 years (range 1 month to 63 years). The average incidence of all IMD subgroups was 1.05 cases per 100,000 person years and was highest in children 0–4 years old (7.08 cases per 100,000 person years) followed by young adults aged 15 to 19 years (4.35 cases per 100,000 person years). Serogroup C IMD occurred in 1.30 cases/100,000 person years in patients aged 0 to 4 years and in 1.92 cases/100,000 person years in patients aged 15 to 19 years. Overall mortality was 11.1%. There was a significant increase ( P =0.001) in IMD due to serogroup B disease within the last 10 years. In contrast, serogroup C disease did not increase during the last decade. Conclusion:Currently, we do not recommend mass vaccination against serogroup C disease in Austria, but young adults aged 15 to 19 years display a high incidence of meningococcal C disease. In this age group, vaccination against serogroup C disease should be considered.     

Implementation of standard operating procedures for the initial empirical antimicrobial therapy for adults--a new computer program at the University Hospital Charité

Nowadays 40-50 % of the patients receive inappropriate antibiotic treatment. Evidence based recommendations are not considered and there is an increasing burden of resistant pathogens. Therefore, standard operating procedures (SOPs) should be implemented considering guidelines and resistant species in the specific ICU. The authors developed algorithms and generated a user friendly computer program available for all ICU physicians all the time.