10 research outputs found
Establishment of induced pluripotent stem cell (iPSC) line from an 8-year old female patient with ischemic Moyamoya disease
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Epsins Regulate Mouse Embryonic Stem Cell Exit from Pluripotency and Neural Commitment by Controlling Notch Activation
Epsins are part of the internalization machinery pivotal to control clathrin-mediated endocytosis. Here, we report that epsin family members are expressed in mouse embryonic stem cells (mESCs) and that epsin1/2 knockdown alters both mESC exits from pluripotency and their differentiation. Furthermore, we show that epsin1/2 knockdown compromises the correct polarization and division of mESC-derived neural progenitors and their conversion into expandable radial glia-like neural stem cells. Finally, we provide evidence that Notch signaling is impaired following epsin1/2 knockdown and that experimental restoration of Notch signaling rescues the epsin-mediated phenotypes. We conclude that epsins contribute to control mESC exit from pluripotency and allow their neural differentiation by appropriate modulation of Notch signaling
Epsins Regulate Mouse Embryonic Stem Cell Exit from Pluripotency and Neural Commitment by Controlling Notch Activation
Epsins are part of the internalization machinery pivotal to control clathrin-mediated endocytosis. Here, we report that epsin family members are expressed in mouse embryonic stem cells (mESCs) and that epsin1/2 knockdown alters both mESC exits from pluripotency and their differentiation. Furthermore, we show that epsin1/2 knockdown compromises the correct polarization and division of mESC-derived neural progenitors and their conversion into expandable radial glia-like neural stem cells. Finally, we provide evidence that Notch signaling is impaired following epsin1/2 knockdown and that experimental restoration of Notch signaling rescues the epsin-mediated phenotypes. We conclude that epsins contribute to control mESC exit from pluripotency and allow their neural differentiation by appropriate modulation of Notch signaling
Establishment of induced pluripotent stem cell (iPSC) line from an 8-year old female patient with ischemic Moyamoya disease
AbstractPeripheral blood mononuclear cells (PBMCs) were collected from an 8-year old female patient affected by ischemic Moyamoya disease (MMD). Patient's PBMCs were reprogrammed using Sendai virus particles delivering the four Yamanaka factors. The footprint free hiPSC line expressed the major pluripotency markers and exhibited a normal karyotype. Cells were competent to give rise to progeny of differentiated cells belonging to the 3 germ layers. This hiPSC line represents a good tool to in vitro model MMD in order to shed light on the cellular and molecular mechanisms responsible for the occurrence of this syndrome
Establishment of induced pluripotent stem cell (iPSC) line from 55-year old male patient with hemorrhagic Moyamoya disease
Generation and characterization of a human iPSC line from an ALS patient carrying the Q66K-MATR3 mutation
Fibroblasts isolated from an Amyotrophic Lateral Sclerosis (ALS)-patient carrying a mutation in Matrin-3 (p.Q66K -MATR3) gene were reprogrammed to the pluripotency stage by using non-integrating episomal plasmids. We generated the Q66K#44DRM induced pluripotent stem cell (iPSC) line that showed regular karyotype, expressed pluripotency-associated markers and were able to properly differentiate into the three germ layers. The heterozygous missense mutation in the MATR3 gene (p.Q66K), which is associated to ALS disease, was present in the generated iPSC line. Resource table [Table presented
Modeling medulloblastoma in vivo and with human cerebellar organoids
Medulloblastoma (MB) is the most common malignant brain tumor in children and among the subtypes, Group 3 MB has the worst outcome. Here, we perform an in vivo, patient-specific screen leading to the identification of Otx2 and c-MYC as strong Group 3 MB inducers. We validated our findings in human cerebellar organoids where Otx2/c-MYC give rise to MB-like organoids harboring a DNA methylation signature that clusters with human Group 3 tumors. Furthermore, we show that SMARCA4 is able to reduce Otx2/c-MYC tumorigenic activity in vivo and in human cerebellar organoids while SMARCA4 T910M, a mutant form found in human MB patients, inhibits the wild-type protein function. Finally, treatment with Tazemetostat, a EZH2-specific inhibitor, reduces Otx2/c-MYC tumorigenesis in ex vivo culture and human cerebellar organoids. In conclusion, human cerebellar organoids can be efficiently used to understand the role of genes found altered in cancer patients and represent a reliable tool for developing personalized therapies
Functional Characterization of Two Secreted SEL1L Isoforms Capable of Exporting Unassembled Substrate*S⃞
SEL1L-A, a transmembrane glycoprotein residing in the endoplasmic reticulum
(ER), is a component of the ER-associated degradation (ERAD) pathway.
Alternative splicing generates two smaller SEL1L isoforms, -B and -C, that
lack the SEL1L-A membrane-spanning region but retain some sel-1-like
repeats, known to be involved in multi-protein interactions and signal
transduction. In this study the functional characteristics of SEL1L-B and -C
were investigated in human cell models. We show that these two isoforms are
induced upon ER stress and activation of the unfolded protein response,
together with SEL1L-A. Using transient transfection experiments (based on
wild-type and mutant SEL1L constructs) combined with several biochemical tests
we show that SEL1L-B and, more prominently, SEL1L-C are secreted
glycoproteins. Although SEL1L-C is in monomeric form, SEL1L-B is engaged in
intramolecular/intermolecular disulfide bonds. Both isoforms localize in
secretory and degradative cellular compartments and in areas of cell-cell
contact. However, whereas SEL1L-B is mainly associated with membranes, SEL1L-C
shows the typical intralumenal localization of soluble proteins and is present
in intercellular spaces. Furthermore, because of its peroxisomal domain,
SEL1L-C localizes to peroxisomes. Both SEL1L-B and -C are involved in sorting
and exporting unassembled Ig-μs but do not affect two other ERAD
substrates, the null Hong Kong variant of α1-antitrypsin, and
mutant α1-AT Z. Overall these findings suggest that SEL1L-B
and -C participate to novel molecular pathways that, in parallel with ERAD,
contribute to the disposure of misfolded/unfolded or orphan proteins through
degradation or secretion
mSEL-1L (Suppressor/Enhancer Lin12-like) Protein Levels Influence Murine Neural Stem Cell Self-renewal and Lineage Commitment*
Murine SEL-1L (mSEL-1L) is a key component of the endoplasmic reticulum-associated degradation pathway. It is essential during development as revealed by the multi-organ dysfunction and in uterus lethality occurring in homozygous mSEL-1L-deficient mice. Here we show that mSEL-1L is highly expressed in pluripotent embryonic stem cells and multipotent neural stem cells (NSCs) but silenced in all mature neural derivatives (i.e. astrocytes, oligodendrocytes, and neurons) by mmu-miR-183. NSCs derived from homozygous mSEL-1L-deficient embryos (mSEL-1L−/− NSCs) fail to proliferate in vitro, show a drastic reduction of the Notch effector HES-5, and reveal a significant down-modulation of the early neural progenitor markers PAX-6 and OLIG-2, when compared with the wild type (mSEL-1L+/+ NSCs) counterpart. Furthermore, these cells are almost completely deprived of the neural marker Nestin, display a significant decrease of SOX-2 expression, and rapidly undergo premature astrocytic commitment and apoptosis. The data suggest severe self-renewal defects occurring in these cells probably mediated by misregulation of the Notch signaling. The results reported here denote mSEL-1L as a primitive marker with a possible involvement in the regulation of neural progenitor stemness maintenance and lineage determination