Long-Term Culture of Mouse Embryonic Stem Cell-Derived Adherent Neurospheres and Functional Neurons

Innumerous protocols, using the mouse embryonic stem (ES) cells as model for in vitro study of neurons functional properties and features, have been developed. Most of these protocols are short lasting, which, therefore, does not allow a careful analysis of the neurons maturation, aging, and death processes. We describe here a novel and efficient long-lasting protocol for in vitro ES cells differentiation into neuronal cells. It consists of obtaining embryoid bodies, followed by induction of neuronal differentiation with retinoic acid of nonadherent embryoid bodies (three-dimensional model), which further allows their adherence and formation of adherent neurospheres (AN, bi-dimensional model). the AN can be maintained for at least 12 weeks in culture under repetitive mechanical splitting, providing a constant microenvironment (in vitro niche) for the neuronal progenitor cells avoiding mechanical dissociation of AN. the expression of neuron-specific proteins, such as nestin, sox1, beta III-tubulin, microtubule-associated protein 2, neurofilament medium protein, Tau, neuronal nuclei marker, gamma-aminobutyric acid, and 5-hydroxytryptamine, were confirmed in these cells maintained during 3 months under several splitting. Additionally, expression pattern of microtubule-associated proteins, such as lissencephaly (Lis1) and nuclear distribution element-like (Ndel1), which were shown to be essential for differentiation and migration of neurons during embryogenesis, was also studied. As expected, both proteins were expressed in undifferentiated ES cells, AN, and nonrosette neurons, although presenting different spatial distribution in AN. in contrast to previous studies, using cultured neuronal cells derived from embryonic and adult tissues, only Ndel1 expression was observed in the centrosome region of early neuroblasts from AN. Mature neurons, obtained from ES cells in this work, display ionic channels and oscillations of membrane electrical potential typical of electrically excitable cells, which is a characteristic feature of the functional central nervous system (CNS) neurons. Taken together, our study demonstrated that AN are a long-term culture of neuronal cells that can be used to analyze the process of neuronal differentiation dynamics. Thus, the protocol described here provides a new experimental model for studying neurological diseases associated with neuronal differentiation during early development, as well as it represents a novel source of functional cells that can be used as tools for testing the effects of toxins and/or drugs on neuronal cells.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo UNIFESP, Dept Farmacol, BR-04044020 São Paulo, BrazilCtr Toxinol Aplicada CEPID, Inst Butantan, São Paulo, BrazilUniv São Paulo, Dept Fisiol & Biofis, São Paulo, BrazilInst Butantan, Genet Lab, BR-05503900 São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Dept Morfol & Genet, BR-04044020 São Paulo, BrazilAtividades Vet Ltda Genet Aplicada, Celltrovet, São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Dept Farmacol, BR-04044020 São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Dept Morfol & Genet, BR-04044020 São Paulo, BrazilWeb of Scienc

Pegylated interferon α plus ribavirin for the treatment of chronic hepatitis C: A multicentre independent study supported by the Italian Drug Agency

Background: Data on the efficacy of Peg-interferon/ribavirin therapy for chronic hepatitis C are mostly derived from treatment of selected patients enrolled in clinical trials. This study aimed to assess the effectiveness of Peg-interferon/ribavirin therapy in "real world" chronic hepatitis C patients in Italy. Methods: Independent observational multicentre study including consecutive patients receiving Peg-interferon/ribavirin in the 18 months before (retrospective phase) and after (prospective phase) the start of the study. Results: 4176 patients were eligible. The final study population consisted of 2051 patients in the retrospective and 2073 in the prospective phase.Sustained virological response was achieved by 1036 patients (50.5%) during the retrospective phase: 325 were genotypes 1/4 (34.1%) and 684 were genotypes 2/3 (67.2%) and by 800 patients (38.6%) during the prospective phase: 300 were genotypes 1/4 (28.4%) and 473 were genotypes 2/3 (51.5%).During multivariate analysis genotypes 2/3 were significantly associated with higher sustained virological response rates; cirrhosis and γ-glutamil-transpeptidase >2 times the normal limit were associated with poorer response. Conclusions: The response to Peg-interferon/ribavirin therapy in "real world" clinical practice is distinctly lower than in registration trials. The difference in response rates was more pronounced among easy-to-treat than among difficult-to-treat hepatitis C virus genotypes. © 2014 Editrice Gastroenterologica Italiana S.r.l