Adriana Bascelli

Salivary chromogranin A, but not α-amylase, correlates with cardiovascular parameters during high-intensity exercise

Introduction  Several studies have shown that activation of the sympathetic nervous system results in the increased secretion of α‐amylase (sAA), an enzyme produced by salivary glands. Recently, chromogranin A (CgA), a soluble protein costored and coreleased with catecholamines from the adrenal medulla and sympathetic nerve endings, has been proposed as a marker of sympathoadrenal medullary system (SAM) activity. The aim of this study was to investigate the behaviour of salivary chromogranin A (sCgA) and sAA during high‐intensity exercise and to analyse their possible correlation with cardiovascular and psychological parameters.

Aβ1–42 stimulated T cells express P-PKC-δ and P-PKC-ζ in Alzheimer disease

Abstract The protein kinase C (PKC) family of enzymes is a regulator of transmembrane signal transduction, and involvement of some PKC isoforms in T-cell activation has been demonstrated. Nevertheless, very little is known about their involvement in the Amyloid β (Aβ)-dependent molecular signals in the T lymphocytes of Alzheimer disease (AD) patients. Therefore, the aim of this study was to investigate the involvement of PKC-α, PKC-δ and PKC-ζ expression and activity in the signaling machinery activated in Aβ-reactive T cells, in adult healthy individuals, elderly healthy subjects, and from patients with AD. The results show that in peripheral T-cells from early AD patients, Aβ1–42 produced a distinct subpopulation highly expressing P-PKC-δ, while in severe AD patients the same treatment induced two distinct P-PKC-δ and P-PKC-ζ T-cell subpopulations. Such subpopulations were not noticeable following CD3/CD28 treatment of the same samples or after treatment of peripheral T cells from healthy adult or elderly subjects with Aβ1–42 or with CD3/CD28. We believe that these findings may be of help in possible attempts to develop further diagnostic strategies useful for the characterization of AD.

Enhancement of TRAIL cytotoxicity by AG-490 in human ALL cells is characterized by downregulation of cIAP-1 and cIAP-2 through inhibition of Jak2/Stat3

The ability of death-inducing tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) to selectively kill a variety of cancer cells has been largely described, but one of the major concerns with the treatment is the occurrence of drug resistance and possible toxic side effects. Here, we report that TRAIL induces apoptosis in Jurkat and SUPT1 T cell lines and in human T-ALL blasts but not in healthy subject-derived peripheral blood mononuclear cells. In parallel, the treatment with TRAIL and Tyrphostin (AG-490), a selective Janus kinase 2 inhibitor, produces an evident enhancement of cytotoxicity, characterized by a significant inhibition of Stat3 phosphorylation compared to controls or to TRAIL alone-treated samples, and associated with a dramatic decrease of both cIAP-1 and cIAP-2 mRNA levels. Downregulation of cIAP-1 and cIAP-2 by specific small interference RNAs significantly amplifies TRAIL-reduced cytotoxicity. All together, these findings strongly indicate that cIAP-1 and cIAP-2 downregulation is a fundamental step in the signaling pathways mediating the combinatorial effect of TRAIL and AG-490 on T cell leukemia. These findings may help to open new routes for the development of less toxic pharmacological strategies in the treatment of patients affected by TRAIL-sensitive leukemias.

Expression and phosphorylation of protein kinase C isoforms in Abeta(1-42) activated T lymphocytes from Alzheimers disease.

The protein kinase C (PKC) family of enzymes is a regulator of transmembrane signal transduction. There is evidence demonstrating altered activity of some PKC isoforms (PKC-α, PKC-δ and PKC-ζ) in the neurons of brains of Alzheimers Disease (AD) sufferers, but little is known about their involvement in the intracellular machinery of amyloid β protein-reactive T lymphocytes in AD. By applying a modified “split-well culture system” for Aβ1–42 reactivity, we carried out flow cytometry analysis and biochemical investigations on the possible involvement of PKC-α, PKC-δ and PKC-ζ in the signalling system activated in Aβ-reactive T cells purified from peripheral blood mononucleate cells (PBMC) from healthy subjects and patients with AD. Flow cytometry analysis of Aβ1–42 activated T lymphocytes in the majority of AD patients highlighted a distinct cellular cluster highly expressing phospho-PKC-δ (P-PKC-δ), while most full-blown AD patients highly expressed two distinct P-PKC-δ and phospho-PKC-ζ (P-PKC-ζ) bright sub-populations. The same investigation performed in freshly purified peripheral T lymphocytes, did not highlight any subpopulation, suggesting that the detection of P-PKC-δ and P-PKC-ζ bright subpopulations is specifically linked to Aβ1–42 activated T lymphocytes. The data presented here, therefore, suggest possible novel hallmarks to discriminate between healthy elderly subjects and beginning or full-blown Alzheimers Disease patients.

Functional mitral regurgitation: from normal to pathological anatomy of mitral valve.

Mitral valve (MV) is composed of several structures working in synchrony to open during diastole and close in systole within the high-pressure systemic environment. Its morphological features ensure a normal leaflet closure that prevents regurgitation of blood back into the left atrium causing loss of ventricular pressure and forward flow. The complex interactions of the normal MV are reliant on each component playing a complete role for the efficient working of the valve. In this review we firstly discuss the overall MV structure in terms of a complex make up of the annulus, the leaflets, their tendinous cords, and the supporting papillary muscles, and then the anatomical changes of each MV components due to left ventricular geometry and function alterations, underlying functional mitral regurgitation.

Erythroid cell differentiation is characterized by nuclear matrix localization and phosphorylation of protein kinases C (PKC) α, δ, and ζ

Protein kinases C (PKC) ζ expression and phosphoryation at nuclear level during dimethyl sulfoxide (DMSO)‐induced differentiation in Friend erythroleukemia cells have been previously reported, suggesting a possible role of this PKC isoform in the DMSO‐related signaling. In order to shed more light on this tantalizing topic, we investigated PKC intracellular and sub‐cellular localization and activity during DMSO‐induced erythroid differentiation. Results indicated that at least PKC α, ζ, and δ are strongly and temporally involved in the DMSO‐induced differentiation signals since their expression and phosphorylation, though at different extents, were observed during treatments. Intriguingly, while PKC α and ζ associate to the nuclear matrix during the differentiation event, PKC δ appears to be residentially associated to the nuclear matrix. Furthermore, an evident downregulation of the β‐globin gene transcription (differentiation hallmark) was detected upon a progressive inhibition of these PKC isoforms by means of specific inhibitors, indicating, therefore, that PKC α, ζ, and δ phosphorylation play a crucial role in the control of erythroid differentiation.

Nuclear protein kinase C-delta: a possible check-point of cell cycle progression.

Protein kinase Cs (PKCs) belong to a serine/threonine kinase family, ubiquitously expressed and claimed to be involved in physiological processes including apoptosis, cell growth and differentiation. The question of the subcellular localization and activity of PKCs remains to be clarified. Here we report that nuclear PKC-δ cooperates to regulate the S-G2/M phase transition of cell cycle, apparently being associated to chromosome condensation and alignment on the metaphase plate.

VEGF response to aerobic training in postmenopause: walking training vs nordic walking

Menopausal transition leads to increased risk of non-communicable chronic diseases, which are characterized by endothelial disruption and dysfunction. Aerobic physical exercise determines an increase of vascular endothelial growth factor (VEGF), a signal protein that stimulates angiogenesis, and recent studies suggest a direct correlation between exercise intensity and VEGF production (1). However, high intensity training is often not recommended for postmenopausal women as a result of cardiovascular and orthopaedic contraindications. The aim of the study was to determine if exercising at the same intensity (i.e. moderate intensity) but involving a more extended muscle mass might induce higher circulating levels of VEGF. Nordic Walking (NW), a form of physical activity where the active use of a pair of dedicated poles is added to regular walking, was compared to walking training (WT). Thirty postmenopausal women were enrolled in the study (57.93±3.55 years old) and randomly assigned to WT (n=15) and NW (n=15). Serum VEGF levels were determined by ELISA before and after exercise training, consisting in three workouts of 40-50 minutes for 13 weeks at intensity between 11 and 13 of a 15-category scale of the ratings of the perceived exertion. The only difference was the use of poles with appropriated technique in NW group. RM-ANOVA with repeated measure for the factor time revealed an effect for time (P=.01) and an interaction effect time x group (P=.041). Post-hoc analysis, consisting in a paired sample t-test for each group, showed that NW increased VEGF whereas WT showed only a tendency (WT: T0=39.68±2.90 T1=40.22±2.56, P=.012; NW: T0=38.22±1.60 T1=42.52±5.97, P=.57). In conclusion, independently from exercise intensity, NW seems to increase VEGF more efficiently than WT, probably as a result of a larger capillary bed actively involved by exercising muscles. This outcome should be taken in consideration when programming exercise training for postmenopausal women.

Functionally differentiated cardiomyocites derived from human amniotic fluid-derived stem cells

Purpose. Human amniotic fluid-derived stem cells (hAFSC) are multipotent stem cells sharing characteristics of both embryonic and adult stem cells. It has been already reported that hAFSC can differentiate toward cardiac lineage though the embryonic body (EB) formation, but the 3D structure and cellular heterogeneity of EB represent an important limitation. Aim of this study was to fully differentiate the hAFSC overcoming the EB limitations. Methods. hAFSC were obtained from normal amniocentesis. Cells cultured in monolayer were exposed sequentially to Ascorbic Acid, 5-Azacytidine, BMP4, ActivinA, VEGF up to 20 days. Differentiation was evaluated monitoring by Western Blot, immunofluorescent and cytometric analyses the expression of CD90, as mesenchymal stem cell marker, and of Nkx2.5, Gata4, sarcomeric α-actinin (αSA), α cardiac myosin heavy chain (αMHC), cardiac T-troponin (TnT)and Connexin43 as cardiac markers. Results. During the differentiation cultures cells underwent a progressive decrease of CD90 accompanied by the induction cardiac markers. After 15 days we evidenced that almost the entire cell population was positive for αMHC, αSA cTnT and Connexin 43 expressions (Table I); moreover, even if the % of Gata4+ and Nkx2.5+ cells did not varied during the culture, a significant increase of Nkx2.5 nuclear translocation (9.1±0.9% vs 18.0±1.8% Nkx2.5 nuclear positive cells in hAFSC and differentiated cells respectively, p<.005, analysis by ImageStream) was detected. Some small beating foci (about 8-10% of the plate) were also observed. Conclusion. We demonstrate that hAFSC can fully differentiate into myocytes giving rise to a homogenous population with cardiac-specific molecular and functional properties.

Angiogenetic effects of physical exercise in menopausal women

Introduction: With menopause women face many changes that may lead to the loss of health related fitness, especially if sedentary. In particular, the estrogens deficiency affects the endothelial function thus increasing the incidence of the cardiovascular diseases. The cardio-protective effects of physical exercise is at least partially due to its ability to improve the health of arterial walls by influencing the endothelial function. Nonetheless, a direct angiogenetic of the physical exercise cannot be ruled out. VEGF is an important modulator of vascular growth but there are contrasting results about its response to physical exercise. Aim of our study was to compare the effects of two aerobic training on the VEGF levels and on the angiogenesis in postmenopausal women. Material and Methods. 34 Postmenopausal women underwent a 13 weeks training. In order to analyse the angiogentic effects, plasmatic VEGF levels were analysed before (T0) and after the training (T1). Moreover, the ability of the T0 and T1 serum to chemoattract endothelial cells and to induce them to form tubes was analyzed. Results: All post-menopausal women increase VEGF (P=0,014) after training. In vitro tests evidenced that when cultured in presence of T1 serum, HUVEC cells improved their ability to form tube (P<0,001) as well as their calibre (P<0,001). Moreover, migration assays evidenced that after training the serum chemoattractive capacity increased significantly (P<0,001) capacity. Conclusion: Our data evidence that aerobic training influence the arterial wall physiology also inducing a angiogenetic affect.