Stem cell differentiation for muscle regeneration

Physical activity has a positive role on muscle remodelling and vascularization, involv-ing stem cells differentiation processes. Indeed, the skeletal muscle homeostasis and repair are maintained by a subset of muscle stem/progenitor cells called Satellite Cells (SCs), while for heart repair and remodelling the cardiac potential of progenitor cells is otherwise expressed by different stem cell types: bone marrow hematopoietic stem cells (BMHSC), bone marrow mesenchymal stem cells (BMMSC), cardiac stem cells and embryonic stem cells. The ε isoform of the PKC family (PKCε) is a serine-threonine kinase that is expressed in muscle and in a variety of other tissues, regulating their homeostasis acting on cell death and differentiation. We focused on the role of PKCε in skeletal, cardiac and smooth muscle differentiation of adult stem cells. We found that inhibition of PKCε prevents myogenic differentiation of the myoblast cell line C2C12 and of primary SCs. In vivo PKCε inhibition resulted in impaired muscle regeneration, as well [1]. On the contrary, in cardiac and smooth muscle differentia-tion of stem cells we observed a negative role of PKCε both in vitro and in vivo [2,3]. In fact, it impaired cardiac markers expression like NKX2.5 and GATA4 but also vascular differ-entiation markers like SMA and PECAM. PKCε should therefore be considered as a finely tuned modulator of muscle cell differentiation

Persistence of Human Herpesvirus 7 in Normal Tissues Detected by Expression of a Structural Antigen

Human herpesvirus 7 (HHV-7) infection in histologically normal human tissues was investigated by immunohistochemical detection of the 85-kDa tegument phosphoprotein (pp85) encoded by the U14 gene. So far, two cell types were recognized as sites of HHV-7 infection in vivo: CD4+ T lymphocytes, believed to be the site of latent infection, and epithelial cells of salivary glands, the site of productive infection and viral shedding. Unexpectedly, cells expressing the HHV-7 structural antigen were detectable in lungs, skin, and mammary glands. Morphologically and phenotypically, they were distinct from lymphocytes. Liver, kidney, and tonsils were positive, although the number of HHV-7-positive cells was low. Large intestine, spleen, and brain were negative. Different from the current notion of the state of HHV-7 in humans, the results show that a variety of tissues harbor cells at a late stage of infection and suggest that HHV-7 causes a persistent rather than a true latent infectio

Impact of sulphurous water Politzer inhalation on audiometric parameters in children with otitis media with effusion

Objectives: The positive effects of spa therapy on ear, nose, and throat pathology are known but robust literature in this field, is still lacking. The aim of this study was to assess through a retrospective analysis, the effects on otitis media with effusion of Politzer endotympanic inhalation of sulphurous waters in children aged 5-9 years. Methods: A cohort of 95 patients was treated with Politzer insufflations of sulphurous water: 58 patients did a cycle consisting of a treatment of 12 days per year for three consecutive years; 37 patients followed the same procedure for 5 years consecutively. The control population was represented by untreated, age-matched children. A standard audiometric test was used before and after each cycle of treatment. Results: One cycle of Politzer inhalation of sulphur-rich water improved the symptoms. Three cycles definitively stabilized the improvement of hearing function. Conclusion: Our results show that otitis media with effusion in children can be resolved by an appropriate non-pharmacological treatment of middle ear with sulphur-rich water

Adenosine Receptors as Mediators of Both Cell Proliferation and Cell Death of Cultured Human Melanoma Cells

Adenosine displays contradictory effects on cell growth: it improves cell proliferation, but it may also induce apoptosis and impair cell survival. Following the pharmacologic characterization of adenosine receptor expression on the human melanoma cell line A375, we chose A375 as our cellular model to define how the extracellular adenosine signals are conveyed from each receptor. By using selective adenosine receptor agonists or antagonists, we found that A2A stimulation reduced cell viability and cell clone formation, whereas, at the same time, it improved cell proliferation. In support of this finding we demonstrated that the stimulation of A2A adenosine receptors stably expressed in Chinese hamster ovary cell clone reproduced deleterious effects observed in human melanoma cells. A3 stimulation counteracted A2A-induced cell death but also reduced cell proliferation. Furthermore, we found that A3 stimulation ensures cell survival. We demonstrated that adenosine triggers a survival signal via A3 receptor activation and it kills the cell through A2A receptor inducing a signaling pathway that involves protein kinase C and mitogen-activated protein kinases

Joint mobility/muscular chain elasticity and motor coordination in a cohort of 9-11 years school children exposed to specifically designed and professionally guided training

Beside the positive role that an active lifestyle plays in the physical and emotional well-being of a child, physically active children have lower risks to encounter injury as adults. However, many groups have reported that only a small population of children in western countries are sufficiently active (1, 2). The aim of this study was to investigate whether joint mobility/muscular elasticity and coordination were related to a merely active lifestyle or could be significantly improved in the presence of a collective, easy-to-perform, but specifically-designed and professionally-guided school program. Specific functional and anthropometric parameters were single-blind tested on 277 children (aged 9-11 years). 148 were randomly assigned to a school-based physical education program specifically designed to increase coordination and elasticity and supervised by professionals, while 129 (control group) continued their usual physical activity at school, with no specific program. The specific program generated a significant improvement of joint mobility and coordination abilities as compared to non-specific physical activity. As a secondary end-point, gender and BMI-related differences emerged during the study, showing that females respond better to a low intensity program, while males benefit of a higher intensity (or a differently designed) program, particularly when belonging to overweight/ obese BMI classes. These results, building up on those from our and other groups, should orient decision-makers in the area of physical exercise for primary school children in favour of specifically designed programs based on demographic and anthropometric data

Activation and nuclear translocation of PKCε promotes skeletal muscle cell differentiation via HMGA1 downregulation

The role of novel PKCs in skeletal muscle differentiation has recently emerged. PKCθ is the most expressed isoform of PKCs in muscle and it promotes the fusion of myoblasts [1]. Recently, we have demonstrated that PKCε is implicated in myocardiocyte differentiation of bone marrow mesenchymal stem cells [2] but the role of PKCε in skeletal muscle cell regeneration has only recently emerged [3]. We here demonstrate that both nuclear and cytoplasmic fractions of PKCε are up-regulated during in vitro C2C12 cell line and satellite cell differentiation. We also show that PKCε is able to modulate myogenic differentiation genes via a downmodulation of HMGA1 proteins that promotes myogenin accumulation and mature myoblast formation. To study the effects of PKCε on muscle regeneration, we have used the in vivo model of CTX-induced skeletal muscle injury. We show that the upregulation of PKCε also occurs in vivo, particularly in the centro-nucleated regenerating fibers that are derived from the fusion process of the resident satellite cells, suggesting a role for PKCε in human satellite cell-driven muscle repair and substitution, with clinically relevant implications in human muscle pathology

PKC epsilon involvement in Th17 in vitro differentiation: implications in psoriasis pathogenesis

Psoriasis is a noncontagious, arytematous-squamose dermatitits affecting both sexes and all races. Although its exact etiology is largely unknown, it is now recognized as one of the most common immune-mediated disorders and several studies demonstrate an impairment of regulatory T-cells (Tregs) function and an up-regulation of IL-17 levels produced by T-helper 17 lymphocytes (Th17)(1,2). Protein kinase C epsilon (PKCε) is a serine/threonine kinase which plays a key role in the proliferation and differentiation of epidermal cells. We have previously demonstrated a role for PKCε in the pathogenesis of the autoimmune disease Hashimoto’s thyroiditis (3). PKCε is over-expressed in CD4+ T lymphocytes isolated from PBMC fraction in patients affected by this pathology and its forced down-modulation primed the TGF-mediated in vitro Treg polarization of human T CD4+ cells. Since it has been demonstrated that PKC-signalling is altered in psoriatic keratinocytes (4), we investigated the involvement of PKCε in Th17 in vitro differentiation and its potentially implication in immune response correlated to psoriasis. Using western blot and real time PCR, we have observed that PKCε protein levels and mRNA increase during Th17-lineage in vitro differentiation from naïve CD4+ T cells with a similar trend of Th17 markers of differentiation STAT3 and RoRyT. Moreover, PKCε overexpression significantly increases STAT3 and phosphorylated STAT3 levels, suggesting that PKCε boosts Th17 polarization. Thereafter, we sought to investigate PKCε expression in CD4+ lymphocytes obtained from peripheral blood of psoriatic patients and we observed that PKCε expression levels are significantly higher compared with healthy donors. Intriguingly, we observed a closely correlation of PKCε expression with PASI index, suggesting an involvement of the kinase with the severity of the disease. Collectively these data suggest that PKCε might be involved in Th17 differentiation, that it could be a key factor to regulate Th17 pathological expansion and therefore a potential psoriatic pharmacological target

Correlation between Protein Kinase Cε expression and thrombotic risk in Primary Myelofibrosis (PMFs)

Myelofibrosis (MF) - either primary (PMF) or arising from a previous PV or ET - is a Philadelphia-negative MPNs characterized by aberrant platelet production and consequent variable platelet count with altered hemostatic function (1). It has already been demonstrated that the risk of thrombotic events is one of the most common co-morbidities associated with PV and ET (2-5). However, risk of thrombotic events in PMF has not been investigated yet. We previously demonstrated that PKCepsilon (PKCε) is over-expressed in platelets from patients with acute myocardial infarction and accounts for their increased reactivity (6). Additionally, we recently showed that PKCε overexpression plays a crucial role in PMF MK impaired differentiation and that its levels correlated with the disease severity (expressed by the IPSS/DIPPS risk category) (7,8). On these bases, we analyzed PKCε expression in platelets from PMF patients, investigating a potential correlation with thrombotic risk and the aggressiveness of the disease. For this study, peripheral blood samples from 6 PMF patients and 3 healthy donors (HD) were collected in Na-citrate tubes. PKCε mRNA and protein levels were determined in platelets purified as described by Carubbi C, 2012. Finally, patients are stratified according to the history of cardio-vascular events and the IPSS/DIPSS risk category. PMF platelets showed significantly higher mRNA levels of PKCε as compared to HD. Protein analysis confirm PKCε over-expression in PMF platelets, almost reaching statistical significance. We then found that platelet from PMF patients who suffered from cardiovascular events display significantly higher levels of PKCε as compared to the one with a negative history. Finally, similarly to what observed in PMF magakaryocytes, we showed a positive correlation between PKCε platelets levels and IPSS/DIPSS risk category, with the lowest levels in low-risk patients and higher levels in high-risk patients. Collectively, our preliminary results indicate that PMF platelets show an aberrant expression of PKCε which correlates with the disease burden and a history of cardiovascular events. This suggests that the over-expression of PKCε may account for PMF platelet altered reactivity and function

Platelet gene expression profile in acute myocardial infarction

Acute myocardial infarction is a sudden event that is fatal in around one-third of patients. It is primarily due to coronary atherosclerotic plaque rupture with subsequent platelet (PLT) activation/aggregation and thrombus formation. PLTs have a key role in the genesis and progression of atherosclerosis and in thrombus formation1. PLTs are anucleated cells which retain mRNA from their megakaryocyte precursor, therefore PLT mRNA is unique in representing a nearly fixed transcriptome2. We tested the hypothesis that platelet transcriptome acts as a fingerprint indicating the development of a future myocardial infarction, with the final goal of identifying a specific STEMI gene-signature, able to discriminate patients with acute event from healthy donors (HD) and from patients affected by stable coronary artery disease (sCAD), the phenotypically closest clinical condition to STEMI. Peripheral blood samples (50mL) were collected in Na-citrate tubes from 20 myocardial infarction patients (MI), 20 sCAD and 20 HD. Highly purified platelets were obtained by leukocyte depletion as previously described3. Platelet RNA extraction were performed by TRIzolTM reagent according to the manufacturer’s protocol. Gene expression profile was analyzed using an Affymetrix GeneChip system (Cancer Genomics and Bioinformatics Laboratory Facility, Kimmel Cancer Center, Jefferson University. Philadelphia, US). The exploratory analysis of PLT transcriptome confirmed differences in gene expression between STEMI, sCAD and HD. Hence, the common differentially expressed genes (DEGs) derived from the STEMI vs sCAD and STEMI vs HD comparisons were obtained and tested by k-nearest neighbor classification and bootstrap. A set of 17 STEMI-related DEGs was identified, showing good sensitivity and specificity for the discrimination of STEMI patients. Overall, we described a STEMI-specific gene expression patterns, suggesting that PLT transcriptome allows to characterize a powerful fingerprint of STEMI theoretically able to predict a future acute event