Mesoangioblasti di topo producono e rilasciano nello spazio extracellulare vescicole di membrana contenenti MMP9 e FGF2 in forma attiva

Shedding of membrane vesicles containing HSP70 and FGF-2 from A6 stem cells.

Sistemas de endomembranas (RE y GOLGI), sistema vacuolar y lisosomas

Mouse A6 stem cells release active FGF-2 into extracellular space through plasma membrane vesicles

In this study, mouse mesoangioblasts were seeded onto bidimensional matrices within three-dimensional porous scaffolds of poly (L-lactic acid) (PLLA), in the presence or absence of a type I collagen coating. The cells were observed under a scanning electron microscope and tested for their adhesion, survival and proliferation. Immunolocalization of heat shock protein (Hsp) 70, an abundant and ubiquitous intracellular protein in these cells, was also performed in sectioned cell-containing scaffolds under a confocal fluorescence microscope to determine if in situ analysis of intracellular constituents was feasible. The data show that PLLA films allow direct cell adhesion and represent an optim…

Nichel,piombo e cadmio inducono risposte cellulari differenti, attivando la sintesi di differenti HSP70 in embrioni di ricci di mare

Selezione di cloni più resistenti allo stress ossidativo dalla popolazione di cellule staminali mesoangioblasti

Stress response in mesangioblast stem cells

Mouse mesoangioblast behaviour when subjected to cellular stress

Membrane vesicles containing matrix metalloproteinase-9 and fibroblast growth factor-2 are released into the extracellular space from mouse mesoangioblast Sstem cells

Certain proteins, including fibroblast growth factor-2 (FGF-2) and matrix metalloproteinase-9 (MMP-9), have proved very effective in increasing the efficacy of mesoangioblast stem cell therapy in repairing damaged tissue. We provide the first evidence that mouse mesoangioblast stem cells release FGF-2 and MMP-9 in their active form through the production of membrane vesicles. These vesicles are produced and turned over continuously, but are stable for some time in the extracellular milieu. Mesoangioblasts shed membrane vesicles even under oxygen tensions that are lower than those typically used for cell culture and more like those of mouse tissues. These findings suggest that mesoangioblast…

Stress response and apoptosis in measoangioblast stem cells

Cellule staminali A6 di topo producono vescicole che contengono HSP70 e FGF-2

MMP2 synthesis in mouse mesoangioblast stem cells is highly regulated

Metalloproteasi nella biologia dei mesoangioblasti di topo

Espressione basale dell’HSP70 inducibile in differenti linee staminali di topo.

Another function of Hsp70 in mesoangioblast stem cells

In recent years, it has been demonstrated that Hsp70 is released in the extracellular space under normal cell culture conditions, and this release is mediated through exosomes. We have demonstrated that A6 cells, a clone of mouse mesoangioblasts, produce and release in the extracellular space membrane vesicles, independently of culture growth conditions. These vesicles contains both structural proteins and biological active molecules, such as FGF-2 and the metalloproteinases MMP 2 and 9. We have also demonstrated that A6 vesicles contain HspP70 and its release is highly regulated. Some of the intracellular Hsp70 is localized on lipid rafts and its concentration in insoluble fraction increas…

Cell clone selected from mab stem cell is more resistent to oxidative stress and retain some ability that could be useful for cell therapy.

Extracellular release of Hsp70 from A6 mouse stem cells

Identification of an HSF2-like factor in sea urchin embryos and its localization in primary mesenchime cells

Intracellular and extracellular Hsp70 in A6 mouse stem cells

Oxidative stress preconditioning of mouse perivascular myogenic progenitors selects a subpopulation of cells with a distinct survival advantage in vitro and in vivo

AbstractCell engraftment, survival and integration during transplantation procedures represent the crux of cell-based therapies. Thus, there have been many studies focused on improving cell viability upon implantation. We used severe oxidative stress to select for a mouse mesoangioblast subpopulation in vitro and found that this subpopulation retained self-renewal and myogenic differentiation capacities while notably enhancing cell survival, proliferation and migration relative to unselected cells. Additionally, this subpopulation of cells presented different resistance and recovery properties upon oxidative stress treatment, demonstrating select advantages over parental mesoangioblasts in …

Hsp70 and Its Molecular Role in Nervous System Diseases

Heat shock proteins (HSPs) are induced in response to many injuries including stroke, neurodegenerative disease, epilepsy, and trauma. The overexpression of one HSP in particular, Hsp70, serves a protective role in several different models of nervous system injury, but has also been linked to a deleterious role in some diseases. Hsp70 functions as a chaperone and protects neurons from protein aggregation and toxicity (Parkinson disease, Alzheimer disease, polyglutamine diseases, and amyotrophic lateral sclerosis), protects cells from apoptosis (Parkinson disease), is a stress marker (temporal lobe epilepsy), protects cells from inflammation (cerebral ischemic injury), has an adjuvant role i…

Ectosomes containing HSP70 and FGF-2 are released from mouse A6 stem cells

Hsp70 functions: inside and outside the cell

Differentiation capability of clones of mouse mesoangioblast stem cells resistant to oxidative stress.

Intracellular and extracellular Hsp70 in mouse mesoangioblast stem cells

Perturbation of Developmental Regulatory Gene Expression by a G-Quadruplex DNA Inducer in the Sea Urchin Embryo.

The G-quadruplex (G4) is a four-stranded DNA structure identified in vivo in guanine-rich regions located in the promoter of a number of genes. Intriguing evidence suggested that small molecules acting as G4-targeting ligands could potentially regulate multiple cellular processes via either stabilizing or disruptive effects on G4 motifs. Research in this field aims to prove the direct role of G4 ligands and/or structures on a specific biological process in a complex living organism. In this study, we evaluate in vivo the effects of a nickel(II)-salnaphen-like complex, named Nisaln, a potent G4 binder and stabilizer, during embryogenesis of the sea urchin embryo. We describe developmental de…

Stress response and apoptosis in mesoangioblasts stem cells

Hsp70 and NF-kB are involved in mouse mesoangioblast stem cells migration.

Stress response in mouse stem cells

Hsp70 level regulates MMP2 expression in mesoangioblast stemj cells

Mesoangioblast stem cell population is non-omogeneous as revealed by transcriptome analysis after a severe oxidative stress.

Esocitosi di Hsp70 mediante vescicole in cellule staminali di topo

Heat Shock Proteins in Multiple Sclerosis Pathogenesis: Friend or Foe?

Multiple Sclerosis is a complex chronic inflammatory, neurodegenerative disease conditioned by genetic, epigenetic and environmental factors. Main pathological features of MS include areas of focal demyelination of white matter characterized by gliosis, neuron and oligodendrocyte loss. Neurodegenerative as well as immune-mediated processes play a role in the pathogenesis of this disease. One of these immunogenic factors could be represented by the heat shock proteins. HSP exhibit cytoprotective and cytostimulatory effects due to their molecular chaperones role, in many brain model misfolding diseases such as Alzheimer’s and Parkinson’s diseases, whereas still no unambiguous results have bee…

La regolazione dell’espressione della MMP2 in mesoangioblasti è dipendente dai livelli della proteina Hsp70.

Hsp70 release from mesoangioblast A6 stem cells through vesicles

Hsp70 localizes differently from chaperone Hsc70 in mouse mesoangioblasts under physiological growth conditions

Mouse A6 mesoangioblasts express Hsp70 even in the absence of cellular stress. Its expression and its intracellular localization were investigated under normal growth conditions and under hyperthermic stress. Immunofluorescence assays indicated that without any stress a fraction of Hsp70 co-localized with actin microfilaments, in the cell cortex and in the contractile ring of dividing cells, while the Hsc70 chaperone did not. Hsp70 immunoprecipitation assays confirmed that a portion of Hsp70 binds actin. Immunoblot assays showed that both proteins were present in the nucleus. After heat treatment Hsp70 and actin continued to co-localize in the leading edge of A6 cells but not on microfilame…

Hsp70 function inside and outside mouse mesoangioblast stem cells

Isolation of cell clones from stem cell population more resistant to oxidative stress for tissue repair.

A6 stem cells release vesicles containing HSP70i

Armazon celulary organelos: citoesqueleto, mitocondria, peroxisomas y nucleo

MMP2 expression in mouse mesoangioblast is dependent on Hsp70 level.

Hsp70 is required for optimal cell proliferation in mouse A6 mesoangioblast stem cells.

Mouse Hsp70 (70 kDa heat shock protein) is preferentially induced by heat or stress stimuli. We previously found that Hsp70 is constitutively expressed in A6 mouse mesoangioblast stem cells, but its possible role in these cells and the control of its basal transcription remained unexplored. Here we report that in the absence of stress, Ku factor is able to bind the HSE (heat shock element) consensus sequence in vitro, and in vivo it is bound to the proximal hsp70 promoter. In addition, we show that constitutive hsp70 transcription depends on the co-operative interaction of different factors such as Sp1 (specificity protein 1) and GAGA-binding protein with Ku factor, which binds the HSE cons…

Mouse mesoangioblasts release Hsp70 in a controlled manner through membrane vesicle shedding

Mesoangioblaststs (Mabs) are mesodermal stem cells associated with vessels which can differentiate into different mesoderm cell types. They have the property to cross endothelial barrier and when injected into circulation they localize into damaged tissues. A6 cells, a clone of mouse Mabs, express Hsp70 protein in physiological conditions and this synthesis may be required to answer to several intra- and/or extra-cellular needs. It was found that Hsp70 may be released outside from several type of cells, but its role remains still undefined. In order to clarify the reason of Hsp70 constitutive expression, we prepared several A6 clones with different levels of Hsp70 expression by stable RNA i…

Role and regulation of HSP70 in A6 mesoangioblast stem cells

A sub-population of mesoangioblasts displays features of resistance and proliferation confirmed by transcriptome analysis.

Genome wide mapping of the MBF-1 binding sites during embryogenesis of the sea urchin reveals it is a chromatin organizer.

The Zinc-finger MBF1 factor is a transcription activator involved in the expression of the early histone genes during development of the sea urchin embryo (1). The DNA-binding domain of MBF1 shares high sequence similarity with that of the CTCF chromatin organizer but, unexpectedly, extensive in silico analysis failed to identify the sea urchin CTCF ortholog (2, 3). This led us to speculate that MBF1 could have co-opted the function of CTCF during evolution of the echinoderms. To support this hypothesis, we performed the genome-wide MBF1-binding sites mapping in the P. lividus genome, by chromatin immunoprecipitation coupled to next generation sequencing (ChIP-Seq). We observed that MBF1 bi…

Extracellular vesicles isolated by cerebrospinal fluid as biomarkers of inflammation in multiple sclerosis and inflammatory neurological diseases.

Mesoangioblast MMP2 regulation is dependent on Hsp70 level

Protective role of heat shock proteins in Parkinson's disease.

Parkinson’s disease (PD) is the second most common neurodegenerative disease after Alzheimer’s disease. Despite a large amount of research, the pathogenetic mechanism of these diseases has not yet been clarified. Abnormal protein folding, oxidative stress, mitochondrial dysfunction, and apoptotic mechanisms have all been reported as causes of neurodegenerative diseases in association with neuroinflammatory mechanisms which, by generating deleterious molecules, could promote the cascade of events leading to neurodegeneration. Heat shock proteins (HSPs) play a central role in preventing protein misfolding and inhibiting apoptotic activity, and represent a class of proteins potentially involve…

Stress response in mesoangioblast stem cells

Stem cells are presumed to survive various stresses, since they are recruited to areas of tissue damage and regeneration, where inflammatory cytokines and cytotoxic cells may result in severe cell injury. We explored the ability of mesoangioblasts to respond to different cell stresses such as heat, heavy metals and osmotic stress, by analyzing heat shock protein (HSP)70 synthesis as a stress indicator. We found that the A6 mesoangioblast stem cells constitutively synthesize HSP70 in a heat shock transcription factor (HSF)-independent way. However, A6 respond to heat shock and cadmium treatment by synthesizing HSP70 over the constitutive expression and this synthesis is HSF1 dependent. The e…

Analisi dell’espressione dell’HSP70 inducubile in cellule staminali ed in tessutiu adulti di topo.

Effects of H2O2 on mesoangioblast stem cells: survival and cell death

Shedding of vesicles from mesoangioblast A6 stem cells

Mesoangioblast behaviour in oxidative stress condition

Hsp70 in mesoangioblast A6 stem cells.

Extracellular Hsp70 Enhances Mesoangioblast Migration via an Autocrine Signaling Pathway

Mouse mesoangioblasts are vessel-associated progenitor stem cells endowed with the ability of multipotent mesoderm differentiation. Therefore, they represent a promising tool in the regeneration of injured tissues. Several studies have demonstrated that homing of mesoangioblasts into blood and injured tissues are mainly controlled by cytokines/chemokines and other inflammatory factors. However, little is known about the molecular mechanisms regulating their ability to traverse the extracellular matrix (ECM). Here, we demonstrate that membrane vesicles released by mesoangioblasts contain Hsp70, and that the released Hsp70 is able to interact by an autocrine mechanism with Toll-like receptor …

Capacità di differenziamento di un clone cellulare da cellule staminali resistenti allo stress ossidativo.

Porous PLLA scaffolds are optimal substrates for internal colonization by A6 mesoangioblasts and immunocytochemical analyses

In the present paper, mouse mesoangioblasts were seeded onto bidimensional matrices and within three-dimensional porous scaffolds of poly(L-lactic acid) (PLLA), in the presence or absence of type I collagen coating, observed under the scanning electron microscope, and tested for their adhesion, survival and proliferation. Immunolocalization of Hsp70, an abundant and ubiquitous intracellular protein in these cells, was also performed in sectioned cell-containing scaffolds under the confocal fluorescence microscope to check whether "in situ" analysis of intracellular constituents was feasible. The data obtained show that PLLA films allow direct cell adhesion and represent an optimal support f…

Ciclo celular, apoptosis y envejecimiento

H2O2 resistant mesoangioblast clone isolation with a distinct survival advantage in vitro and in vivo

The release of molecules from damaged tissues stimulates both resident and circulating stem cells to initiate a tissue repair programme. 1 However, during transplantation procedures the therapeutic efficacy of stem cells is compromised by reduced homing capability towards the target site.2,3 Furthermore, cell survival is very low and many studies focused on improving cell viability upon implantation. In this study, we performed in vitrosevere oxidative stress to select some more resistant mouse mesoangioblasts, vessel-associated progenitor stem cells endowed with the ability of multipotent mesoderm differentiation. We found that the selected subpopulation retains selfrenewal and myogenic di…

Autophagy and apoptosis regolate survival of mesoangioblast stem cells subjected to oxidative stress

Mesoangioblast A6 stem cells release vesicles containing the inducible HSP70

Ku factor is responsible of Hsp70 basal transcription in mouse mesoangioblasts

Inducible HSP70 localization in mesoangioblast A6 stem cells

Hsp70 is involved in MMP2 level in mouse mesoangioblast stem cells

Extracellular membrane vesicles as a mechanism of cell-to-cell communication: advantages and disadvantages.

Microvesicles represent a newly identified mechanism of intercellular communication. Two different types of microvesicles have been identified: membrane-derived vesicles (EVs) and exosomes. EVs originate by direct budding from the plasma membrane, while exosomes arise from ectocytosis of multivesicular bodies. Recent attention has focused on the capacity of EVs to alter the phenotype of neighboring cells to make them resemble EV-producing cells. Stem cells are an abundant source of EVs, and the interaction between stem cells and the microenvironment (i.e., stem cell niche) plays a critical role in determining stem cell phenotype. The stem cell niche hypothesis predicts that stem cell number…

Cell clones more resistant to oxidative stress selecte from embryonic and adult mesoangioblast stem cell population.

Transcriptome analysis after a strong oxidative stress highlighted a mesoangioblast stem cell sub-population with important different capability

Rapid changes in heat-shock cognate 70 levels, heat-shock cognate phosphorylation state, heat-shock transcription factor, and metal transcription factor activity levels in response to heavy metal exposure during sea urchin embryonic development.

The aim of the present study was to analyze and compare the effects of several metals on the embryos of the sea urchin Paracentrotus lividus, a key species within the Mediterranean Sea ecosystem. Embryos were continuously exposed from fertilization to the following metals: 0.6 mg/l copper, 3 mg/l lead, and 6 mg/l nickel. The embryos were then monitored for metal responses at the gastrula stage, which occurred 24 h after exposure. A biochemical multi-experimental approach was taken and involved the investigation of the levels of HSC70 expression and the involvement of heat shock factor (HSF) and/or metal transcription factor (MTF) in the response. Immunoblotting assays and electrophoretic mo…

Regeneration in invertebrates

The mechanisms of regeneration are reviewed from a genetic, cytological and molecular biological points of view. Planarians and Hydra have been chosen and illustrated as biological examples.