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Anastasia L.,University of Milan | Anastasia L.,Laboratory of Stem Cells for Tissue Engineering | Pelissero G.,Laboratory of Stem Cells for Tissue Engineering | Venerando B.,University of Milan | And 2 more authors.
Cell Death and Differentiation | Year: 2010

The possibility of reprogramming adult somatic cells into pluripotent stem cells (iPSCs) has generated a renewed interest into stem cell research and promises to overcome several key issues, including the ethical concerns of using human embryonic stem cells and the difficulty of obtaining large numbers of adult stem cells (Belmonte et al., Nat Rev Genet, 2009). This approach is also not free from challenges like the mechanism of the reprogramming process, which has yet to be elucidated, and the warranties for safety of generated pluripotent cells, especially in view of their possible therapeutic use. Very recently, several new reprogramming methods have surfaced, which seem to be more appropriate than genetic reprogramming. Particularly, chemically induced pluripotent cells (CiPSs), obtained with recombinant proteins or small synthetic molecules, may represent a valid approach, simpler and possibly safer than the other ones.


Rota P.,University of Milan | Anastasia L.,University of Milan | Anastasia L.,Laboratory of Stem Cells for Tissue Engineering | Allevi P.,University of Milan
Organic and Biomolecular Chemistry | Year: 2015

The current analytical protocol used for the GC-MS determination of free or 1,7-lactonized natural sialic acids (Sias), as heptafluorobutyrates, overlooks several transformations. Using authentic reference standards and by combining GC-MS and NMR analyses, flaws in the analytical protocol were pinpointed and elucidated, thus establishing the scope and limitations of the method. It was demonstrated that (a) Sias 1,7-lactones, even if present in biological samples, decompose under the acidic hydrolysis conditions used for their release; (b) Sias 1,7-lactones are unpredicted artifacts, accidentally generated from their parent acids; (c) the N-acetyl group is quantitatively exchanged with that of the derivatizing perfluorinated anhydride; (d) the partial or complete failure of the Sias esterification-step with diazomethane leads to the incorrect quantification and structure attribution of all free Sias. While these findings prompt an urgent correction and improvement of the current analytical protocol, they could be instrumental for a critical revision of many incorrect claims reported in the literature. This journal is © The Royal Society of Chemistry 2015.


Rota P.,University of Milan | Cirillo F.,Laboratory of Stem Cells for Tissue Engineering | Piccoli M.,Laboratory of Stem Cells for Tissue Engineering | Gregorio A.,University of Milan | And 3 more authors.
Chemistry - A European Journal | Year: 2015

Previous studies demonstrated that reducing the GM3 content in myoblasts increased the cell resistance to hypoxic stress, suggesting that a pharmacological inhibition of the GM3 synthesis could be instrumental for the development of new treatments for ischemic diseases. Herein, the synthesis of several dephosphonated CMP-Neu5Ac congeners and their anti-GM3-synthase activity is reported. Biological activity testes revealed that some inhibitors almost completely blocked the GM3-synthase activity in vitro and reduced the GM3 content in living embryonic kidney 293A cells, eventually activating the epidermal growth factor receptor (EGFR) signaling cascade. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Quattrocelli M.,Catholic University of Leuven | Quattrocelli M.,University of Perugia | Palazzolo G.,Catholic University of Leuven | Palazzolo G.,Laboratory of Stem Cells for Tissue Engineering | And 12 more authors.
Journal of Pathology | Year: 2011

Mesoangioblasts (MABs) are a subset of muscle-derived pericytes able to restore dystrophic phenotype in mice and dogs. However, their lifespan is limited and they undergo senescence after 25-30 population doublings. Recently, induced pluripotent stem cells (iPSCs) generated from reprogrammed fibroblasts have been demonstrated to have in vitro and in vivo myogenic potential when sorted for the SM/C-2.6 antigen. Furthermore, chimeric mice from mdx-iPSCs (DYS-HAC) cells showed tissue-specific expression of dystrophin. Nevertheless, myogenic differentiation protocols and the potential of iPSCs generated from different cell sources still present unanswered questions. Here we show that iPSCs generated from prospectively sorted MABs (MAB-iPSCs) are pluripotent as fibroblast-derived iPSCs (f-iPSCs). However, both teratoma formation and genetic cell manipulation assays identify a durable epigenetic memory in MAB-iPSCs, resulting in stronger myogenic commitment. Striated muscle tissue accounts for up to 70% of MAB-iPSC teratomas. Moreover, transfection with Pax3 and Pax7 induces a more robust myogenic differentiation in MAB-iPSCs than in f-iPSCs. A larger amount of CD56+ progenitors can be sorted from the MAB-iPSCs differentiating pool and, after transplantation into αsg-KO mice, can efficiently participate to skeletal muscle regeneration and restore αsg expression. Our data strongly suggest that iPSCs are a heterogeneous population and, when generated from myogenic adult stem cells, they exhibit a stronger commitment, paving the way for creating custom-made cell protocols for muscular dystrophies. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.


Massaccesi L.,University of Milan | Burlina A.,University of Padua | Baquero C.J.,University of Milan | Goi G.,University of Milan | And 2 more authors.
Clinical Biochemistry | Year: 2011

Objectives: ERT application to Fabry's disease patients needs sensitive assay method of the missing enzyme (α-d-galactosidase A) to achieve early diagnosis. Design and methods: A new fluorimetric assay method of alpha;-d-galactosidase A was developed, using whole blood (WB) from 30 healthy individuals, 7 hemizygous males and 7 heterozygous females with Fabry's disease. This method was compared with the traditional dried blood spot (DBS) method. Results: WB method analytical characteristics are: linearity up to 2000. mU/L; detection limit: 4. mU/L; linearity versus time: 6. h; enzyme stability: 7. days at 4 °C; total analytical imprecision: from 3.27% to 5.72%. Sensitivity was higher in WB than DBS method. All hemizygous Fabry's patients were identified by both the WB and DBS methods. With regards to the seven heterozygous carriers five could be identified by the WB methods and three by the DBS method. Conclusion: The WB assay method for α-d-galactosidase A appears to be reliable and proposable as a routine method for prompt diagnosis of Fabry disease in selected at-risk populations. © 2011 The Canadian Society of Clinical Chemists.


Bugiardini E.,University of Milan | Rivolta I.,University of Milan Bicocca | Binda A.,University of Milan Bicocca | Soriano Caminero A.,Penn State Hershey Medical Center | And 8 more authors.
Neuromuscular Disorders | Year: 2015

In myotonic dystrophy type 2 (DM2), an association has been reported between early and severe myotonia and recessive chloride channel (. CLCN1) mutations. No DM2 cases have been described with sodium channel gene (. SCN4A) mutations. The aim is to describe a DM2 patient with severe and early onset myotonia and co-occurrence of a novel missense mutation in SNC4A. A 26-year-old patient complaining of hand cramps and difficulty relaxing her hands after activity was evaluated at our department. Neurophysiology and genetic analysis for DM1, DM2, CLCN1 and SCN4A mutations were performed. Genetic testing was positive for DM2 (2650 CCTG repeat) and for a variant c.215C>T (p.Pro72Leu) in the SCN4A gene. The variation affects the cytoplasmic N terminus domain of Nav1.4, where mutations have never been reported. The biophysical properties of the mutant Nav1.4 channels were evaluated by whole-cell voltage-clamp analysis of heterologously expressed mutant channel in tsA201 cells. Electrophysiological studies of the P72L variant showed a hyperpolarizing shift (-5mV) of the voltage dependence of activation that may increase cell excitability. This case suggests that SCN4A mutations may enhance the myotonic phenotype of DM2 patients and should be screened for atypical cases with severe myotonia. © 2015 Elsevier B.V..


PubMed | University of Pavia, Service of Laboratory Medicine, Research Laboratories, Clinical Cardiology Unit and CCU and 3 more.
Type: | Journal: Clinica chimica acta; international journal of clinical chemistry | Year: 2016

Myotonic dystrophy (DM) is a genetic disorder caused by nucleotide repeats expansion. Sudden death represents the main cause of mortality in DM patients. Here, we investigated the relationship between serum cardiac biomarkers with clinical parameters in DM patients.Case-control study included 59 DM patients and 22 healthy controls. An additional group of 62 controls with similar cardiac defects to DM were enrolled.NT-proBNP, hs-cTnT and CK levels were significantly increased in DM patients compared to healthy subjects (p=0.0008, p<0.0001, p<0.0001). Also, hs-cTnT levels were significantly higher in DM compared to control group with cardiac defects (p=0.0003). Positive correlation was found between hs-cTnT and hs-cTnI in both DM patients and controls (p=0.019, p=0.002). Independently from the age, the risk of DM disease was positively related to an increase in hs-cTnT (p=0.03). On the contrary, the risk of DM was not related to hs-cTnI, but was evidenced a role of PR interval (p=0.03) and CK (p=0.08).The levels of hs-cTnT were significantly higher in DM patients. Analysis, with anti-cTnT, shows that this increase might be linked to heart problems. This last finding suggests that hs-cTnT might represent a helpful serum biomarker to predict cardiac risk in DM disease.


PubMed | Laboratory of Stem Cells for Tissue Engineering and University of Milan
Type: Journal Article | Journal: Chemistry (Weinheim an der Bergstrasse, Germany) | Year: 2015

Previous studies demonstrated that reducing the GM3 content in myoblasts increased the cell resistance to hypoxic stress, suggesting that a pharmacological inhibition of the GM3 synthesis could be instrumental for the development of new treatments for ischemic diseases. Herein, the synthesis of several dephosphonated CMP-Neu5Ac congeners and their anti-GM3-synthase activity is reported. Biological activity testes revealed that some inhibitors almost completely blocked the GM3-synthase activity in vitro and reduced the GM3 content in living embryonic kidney 293A cells, eventually activating the epidermal growth factor receptor (EGFR) signaling cascade.


PubMed | Laboratory of Stem Cells for Tissue Engineering and University of Milan
Type: | Journal: International journal of cardiology | Year: 2016

Hypoxia is a common feature of many congenital heart defects (CHDs) and significantly contributes to their pathophysiology. Thus, understanding the mechanism underlying cell response to hypoxia is vital for the development of novel therapeutic strategies. Certainly, the hypoxia inducible factor (HIF) has been extensively investigated and it is now recognized as the master regulator of cell defense machinery counteracting hypoxic stress. Along this line, we recently discovered and reported a novel mechanism of HIF activation, which is mediated by sialidase NEU3. Thus, aim of this study was to test whether NEU3 played any role in the cardiac cell response to chronic hypoxia in congenital cyanotic patients.Right atrial appendage biopsies were obtained from pediatric patients with cyanotic/non-cyanotic CHDs and processed to obtain mRNA and proteins. Real-Time PCR and Western Blot were performed to analyze HIF-1 and its downstream targets expression, NEU3 expression, and the NEU3 mediated effects on the EGFR signaling cascade.Cyanotic patients showed increased levels of HIF-1, NEU3, EGFR and their downstream targets, as compared to acyanotic controls. The same patients were also characterized by increased phosphorylation of the EGFR signaling cascade proteins. Moreover, we found that HIF-1 expression levels positively correlated with those recorded for NEU3 in both cyanotic and control patients.Sialidase NEU3 plays a central role in activating cell response to chronic hypoxia inducing the up-regulation of HIF-1, and this represent a possible novel tool to treat several CHD pathologies.


PubMed | University of Rome Tor Vergata, University of Milan Bicocca, Penn State Hershey Medical Center, University of Milan and 2 more.
Type: Case Reports | Journal: Neuromuscular disorders : NMD | Year: 2015

In myotonic dystrophy type 2 (DM2), an association has been reported between early and severe myotonia and recessive chloride channel (CLCN1) mutations. No DM2 cases have been described with sodium channel gene (SCN4A) mutations. The aim is to describe a DM2 patient with severe and early onset myotonia and co-occurrence of a novel missense mutation in SNC4A. A 26-year-old patient complaining of hand cramps and difficulty relaxing her hands after activity was evaluated at our department. Neurophysiology and genetic analysis for DM1, DM2, CLCN1 and SCN4A mutations were performed. Genetic testing was positive for DM2 (2650 CCTG repeat) and for a variant c.215C>T (p.Pro72Leu) in the SCN4A gene. The variation affects the cytoplasmic N terminus domain of Nav1.4, where mutations have never been reported. The biophysical properties of the mutant Nav1.4 channels were evaluated by whole-cell voltage-clamp analysis of heterologously expressed mutant channel in tsA201 cells. Electrophysiological studies of the P72L variant showed a hyperpolarizing shift (-5mV) of the voltage dependence of activation that may increase cell excitability. This case suggests that SCN4A mutations may enhance the myotonic phenotype of DM2 patients and should be screened for atypical cases with severe myotonia.

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