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Pessina A.,University of Milan | Bonomi A.,University of Milan | Sisto F.,University of Milan | Baglio C.,University of Milan | And 4 more authors.
Cell Biology International | Year: 2010

UCB (human umbilical cord blood) contains cells able to differentiate into non-haematopoietic cell lineages. It also contains cells similar to primitive ESCs (embryonic stem cells) that can differentiate into pancreatic-like cells. However, few data have been reported regarding the possibility of expanding these cells or the differential gene expression occurring in vitro. In this study, we expanded formerly frozen UCB cells by treatment with SCF (stem cell factor) and GM-CSF (granulocyte-macrophage colony stimulating factor) in the presence of VPA (valproic acid). Gene expression profiles for beta cell differentiation and pluripotency (embryo stem cell phenotype) were analysed by RT-PCR and immunocytochemistry. The results show a dramatic expansion (150-fold) of haematopoietic progenitors (CD45+/CD133+) which also expressed embryo markers of pluripotency (nanog, kfl-4, sox-2, oct-3/4 and c-myc), nestin, and pancreatic markers such as pax-4, ngn-3, pdx-1 and syt-1 (that is regulated by pdx-1 and provides the cells with a Ca++ regulation mechanism essential for insulin exocytosis). Our results show that UCB cells can be expanded to produce large numbers of cells of haematopoietic lineage that naturally (without the need of retroviral vectors or transposons) express a gene pattern compatible with endocrine pancreatic precursors and markers of pluripotency. Further investigations are necessary to clarify, first, whether in this context, the embryogenes expressed are functional or not, and secondly, since these cells are safer than cells transfected with retroviral vectors or transposons, whether they would represent a potential tool for clinical application. © The Author(s) Journal compilation © 2010 Portland Press Limited. Source


Pessina A.,University of Milan | Sisto F.,University of Milan | Cocce V.,University of Milan | Cavicchini L.,University of Milan | And 3 more authors.
Cell Biology and Toxicology | Year: 2011

The mesenchymal stromal cell line SR-4987 has been established in our laboratory from the bone marrow of BDF/1 mice. Recent information on mesenchymal stem cells biology and the need to deal with well-characterized cell lines suggest to critically consider the existent data on this cell line by updating them with new investigations on growth parameters, in vitro plasticity, and drug sensitivity to anti-cancer, anti-inflammatory, and a histone deacetylase inhibitor. SR-4987 cells show a population doubling time of 24.5±5.4 h, a plating efficiency of 2.87±1.19%, and under stimulation maintain only in part their multipotency by differentiating towards chondro-osteogenic lineages but not into adipogenic. Surprisingly, these mesenchymal stromal cells differentiate spontaneously into osteoblast-like cells and this is significantly stimulated by valproic acid. SR-4987 cells show a dramatic resistance to paclitaxel (PTX) with a resistance index of 39.6 times (evaluated versus MOLT-4 leukemia) and of 68.2 (versus HT-29 colorectal carcinoma). SR-4987 resistance is reversed by verapamil and correlates with high expression of Pglycoprotein that is down-modulated by PTX. Taken together, our results indicated that SR-4987 line is a very interesting cell model useful to investigate both drug sensitivity resistance and physiopathological aspects related to mesenchymal cell function. © Springer Science+Business Media B.V. 2010. Source


Botturi A.,Fondazione Istituto Neurologico Besta | Prodi E.,Fondazione Istituto Neurologico Besta | Silvani A.,Fondazione Istituto Neurologico Besta | Gaviani P.,Fondazione Istituto Neurologico Besta | And 3 more authors.
Neurological Sciences | Year: 2012

Partial seizures can be due to a growing cerebral lesion, which may be tumoral or inflammatory/infectious in nature. The differential diagnosis is obviously important; increasing immigration to Europe from Africa is leading to an increase of infectious disease involving also the central nervous system. The authors report imaging the a case of a brain tuberculoma due to Mycobacterium africanum mimicking brain tumor, in which diagnosis was possible by inoculum in guinea-pig of material obtained by mediastinal biopsy of enlarged lymph nodes. Specific treatment led to marked reduction in the size of the brain lesion. © Springer-Verlag 2011. Source


Van Berge L.,VU University Amsterdam | Hamilton E.M.,VU University Amsterdam | Linnankivi T.,University of Helsinki | Uziel G.,Fondazione Istituto Neurologico Besta | And 19 more authors.
Brain | Year: 2014

Leukoencephalopathy with brainstem and spinal cord involvement and lactate elevation is a disorder caused by recessive mutations in the gene DARS2, which encodes mitochondrial aspartyl-tRNA synthetase. Recent observations indicate that the phenotypic range of the disease is much wider than initially thought. Currently, no treatment is available. The aims of our study were (i) to explore a possible genotype-phenotype correlation; and (ii) to identify potential therapeutic agents that modulate the splice site mutations in intron 2 of DARS2, present in almost all patients. A cross-sectional observational study was performed in 78 patients with two DARS2 mutations in the Amsterdam and Helsinki databases up to December 2012. Clinical information was collected via questionnaires. An inventory was made of the DARS2 mutations in these patients and those previously published. An assay was developed to assess mitochondrial aspartyl-tRNA synthetase enzyme activity in cells. Using a fluorescence reporter system we screened for drugs that modulate DARS2 splicing. Clinical information of 66 patients was obtained. The clinical severity varied from infantile onset, rapidly fatal disease to adult onset, slow and mild disease. The most common phenotype was characterized by childhood onset and slow neurological deterioration. Full wheelchair dependency was rare and usually began in adulthood. In total, 60 different DARS2 mutations were identified, 13 of which have not been reported before. Except for 4 of 42 cases published by others, all patients were compound heterozygous. Ninety-four per cent of the patients had a splice site mutation in intron 2. The groups of patients sharing the same two mutations were too small for formal assessment of genotype-phenotype correlation. However, some combinations of mutations were consistently associated with a mild phenotype. The mitochondrial aspartyl-tRNA synthetase activity was strongly reduced in patient cells. Among the compounds screened, cantharidin was identified as the most potent modulator of DARS2 splicing. In conclusion, the phenotypic spectrum of leukoencephalopathy with brainstem and spinal cord involvement and lactate elevation is wide, but most often the disease has a relatively slow and mild course. The available evidence suggests that the genotype influences the phenotype, but because of the high number of private mutations, larger numbers of patients are necessary to confirm this. The activity of mitochondrial aspartyl-tRNA synthetase is significantly reduced in patient cells. A compound screen established a 'proof of principle' that the splice site mutation can be influenced. This finding is promising for future therapeutic strategies. © 2013 The Author. Source


Zampieri S.,University of Santa Maria in Ecuador | Cattarossi S.,University of Santa Maria in Ecuador | Ramirez A.M.,National University of Cordoba | Rosano C.,Patologia Molecolare Integrata A.O.U. IRCSS San Martino IST | And 12 more authors.
PLoS ONE | Year: 2012

Sandhoff disease (SD) is a lysosomal disorder caused by mutations in the HEXB gene. To date, 43 mutations of HEXB have been described, including 3 large deletions. Here, we have characterized 14 unrelated SD patients and developed a Multiplex Ligation-dependent Probe Amplification (MLPA) assay to investigate the presence of large HEXB deletions. Overall, we identified 16 alleles, 9 of which were novel, including 4 sequence variation leading to aminoacid changes [c.626C>T (p.T209I), c.634C>A (p.H212N), c.926G>T (p.C309F), c.1451G>A (p.G484E)] 3 intronic mutations (c.1082+5G>A, c.1242+1G>A, c.1169+5G>A), 1 nonsense mutation c.146C>A (p.S49X) and 1 small in-frame deletion c.1260_1265delAGTTGA (p.V421_E422del). Using the new MLPA assay, 2 previously described deletions were identified. In vitro expression studies showed that proteins bearing aminoacid changes p.T209I and p.G484E presented a very low or absent activity, while proteins bearing the p.H212N and p.C309F changes retained a significant residual activity. The detrimental effect of the 3 novel intronic mutations on the HEXB mRNA processing was demonstrated using a minigene assay. Unprecedentedly, minigene studies revealed the presence of a novel alternative spliced HEXB mRNA variant also present in normal cells. In conclusion, we provided new insights into the molecular basis of SD and validated an MLPA assay for detecting large HEXB deletions. © 2012 Zampieri et al. Source

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