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

Study of cardiomyogenic potential of human Amniotic Fluid Stem Cells

It has been shown that Amniotic fluid stem cells (AFSCs) have characteristics intermediate between pluripotent embryonic and lineage-restricted adult stem cells, and are non-tumorigenic and low immunogenic. Moreover, they are obtained without destroying human embryos, so that preventing most of the ethical and social controversy. Human AFSCs express some genes specific of both embryonic (OCT3/4, NANOG, c-MYC) and primordial germ stem cells (Fragilis, Stella, c-KIT). We have demonstrated that hAFSCs form in vitro embryoid bodies (EBs) and express markers of three germ layers. Studies reported the ability of hAFSCs to differentiate in vitro into adipocytes and osteocytes, but only few data are available on their cardiomyogenic potential. Aim of this study is to analyze hAFSCs differentiation through the cardiac pathway. Embryonic Bodies (EBs) were obtained from hAFSCs cultured in presence of ascorbic acid and 5-aza-2’-deoxycytidine. Cardiomyogenic potential of hAFSCs and EBs was explored by WB and immunoflorescent analyses of specific markers. Simultaneous quantitative detection and cellular localization analysis of cardiomyogenic markers were conducted with an ImageStream multispectral imaging flow cytometer (Amnis-Seattle, WA) equipped with IDEAS statistical software. We evidenced that both AFSCs and EBs at early stage express Nkx2.5, a transcription factor expressed by cardiomyocytes precursor cells. Moreover, ImageStream imaging cytometer analysis evidenced that EBs formation was accompanied by an up-regulation of Nkx2.5 expression (36.54±1.83% and 64.68±3.23% positive cells in hAFSC and EBs respectively, p<.005) and by a significant nuclear translocation (12.98±0.64% and 37.98±1.9% nuclear positive cells in hAFSC and EBs respectively, p<.005). Microscopical analysis evidenced inside the EBs cells positive for the presence of cardiac α-Myosin heavy chain protein structurally organized in oriented filaments. Moreover, we detected cells expressing Connexin43. These results evidenced that EBs obtained from hAFSCs cultured in permissive conditions terminally differentiate into cardiomyocytes and suggest them as possible model to study the cardiac differentiation

The phosphoinositide 3-kinase role in IL-6 induction to differentiation of rat embryonic cardiomyocytes

Purpose. Cardiomyocytes express IL-6 and its signal transducer, 130-kDa glycoprotein (gp130) that influence cell growth, apoptosis, differentiation and survival by an autocrine pathway. High levels of circulating IL-6 have been reported in patients with congestive heart failure (HF) and after myocardial infarction and IL-6-gp130-signaling participates in HF prevention and compensatory hypertrophy, influencing remodeling processes and inducing Protein kinase C (PKC)-dependent apoptosis. Recent studies demonstrated the presence of precursor cells able to differentiate into cardiomyocytes in the adult heart through signaling pathways similar to those in the embryonic heart thus participating to the physiologic repair of the injured heart. In this line, the study of the embryonic signaling may represent an important cue to understand the molecular bases of the regenerative capacity myocardial progenitors. Aim of this study was to investigate the signal transduction pathways evoked by IL-6 treatment on cardiomyoblasts and its possible differentiating effects. Methods. H9c2 cells cultured in medium supplemented with 1% FBS (differentiation-promoting medium) in presence of IL-6 (10 ng/ml) up to three days. Results. Western Blot and Immunofluorence analysis demonstrated that Il-6 after 3 days of treatment induced a marked increase of the expression of α-myosin heavy chain (α-MHC; terminal cardiac differentiation marker) together with a microfilament reorganization and morphological modifications, that included mono-nucleated cells elongation and fusion into multinucleated tubes. This process was accompanied by an evident nuclear translocation of Nkx2.5 (early myocardial development transcription factor), and by a sub-cellular redistribution of gp130. Results suggest that the biological effects evoked by IL6 were at least partially mediated by PI3K through Akt and PKCzeta pathways modulation, as confirmed by the varied phosphorylated PI3K level observed after 30 min of IL-6 treatment and PI3K induction of downstream PKCzeta phosphorilation, but not PKCalpha and PKCdelta, whereas Akt de-phosphorylation was detected. Conclusions. Our observations evidenced that PI3K is a key regulator of IL-6- induction of embryonic cardiomyocytes differentiation by PKCzeta and Akt-signalling pathways. These data suggest a possible role of IL-6 dependent pathways in regenerative capacity of myocardial cells following injuries

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