Osteogenic Differentiation of Mesenchymal Stromal Cells: A Comparative Analysis Between Human Subcutaneous Adipose Tissue and Dental Pulp.

White adipose tissue is a source of mesenchymal stromal/stem cells (MSCs) that are actively studied for their possible therapeutic use in bone tissue repair/remodeling. To better appreciate the osteogenic potential of these cells, we compared some properties of MSCs from human subcutaneous adipose tissue [subcutaneous-adipose stromal cells (S-ASCs)] and dental pulp stem cell (DPSCs) of third-impacted molars, the latter representing a well-established MSC source. Both undifferentiated cell types showed similar fibroblast-like morphology and mesenchymal marker expression.

Development of a new HPLC method using fluorescence detection without derivatization for determining purine nucleoside phosphorylase activity in human plasma.

Purine nucleoside phosphorylase (PNP) activity is involved in cell survival and function, since PNP is a key enzyme in the purine metabolic pathway where it catalyzes the phosphorolysis of the nucleosides to the corresponding nucleobases. Its dysfunction has been found in relevant pathological conditions (such as inflammation and cancer), so the detection of PNP activity in plasma could represent an attractive marker for early diagnosis or assessment of disease progression. Thus the aim of this study was to develop a simple, fast and sensitive HPLC method for the determination of PNP activity in plasma.

Potentiation of temozolomide antitumor effect by purine receptor ligands able to restrain the in vitro growth of human glioblastoma stem cells.

Glioblastoma multiforme (GBM), the most common and aggressive brain tumor in humans, comprises a population of stem-like cells (GSCs) that are currently investigated as potential target for GBM therapy. Here, we used GSCs isolated from three different GBM surgical specimens to examine the antitumor activity of purines. Cultured GSCs expressed either metabotropic adenosine P1 and ATP P2Y receptors or ionotropic P2X7 receptors.

Calcitonin-induced effects on amniotic fluid-derived mesenchymal stem cells.

Background/aims: Mesenchymal stem cells from human amniotic fluid (huAFMSCs) can differentiate into multiple lineages and are not tumorigenic after transplantation, making them good candidates for therapeutic purposes. The aim was to determine the effects of calcitonin on these huAFMSCs during osteogenic differentiation, in terms of the physiological role of calcitonin in bone homeostasis.

Methods: For huAFMSCs cultured under different conditions, we assayed: expression of the calcitonin receptor, using immunolabelling techniques; proliferation and osteogenesis, using colorimetric and enzymatic assays; intracellular Ca(2+) and cAMP levels, using videomicroscopy and spectrophotometry.

Molecular and phenotypic characterization of human amniotic fluid-derived cells: a morphological and proteomic approach.

Mesenchymal Stem Cells derived from Amniotic Fluid (AFMSCs) are multipotent cells of great interest for regenerative medicine. Two predominant cell types, that is, Epithelial-like (E-like) and Fibroblast-like (F-like), have been previously detected in the amniotic fluid (AF). In this study, we examined the AF from 12 donors and observed the prevalence of the E-like phenotype in 5, whereas the F-like morphology was predominant in 7 samples.

Guanosine protects glial cells against 6-hydroxydopamine toxicity.

Increasing body of evidence indicates that neuron-neuroglia interaction may play a key role in determining the progression of neurodegenerative diseases including Parkinson's disease (PD), a chronic pathological condition characterized by selective loss of dopaminergic (DA) neurons in the substantia nigra. We have previously reported that guanosine (GUO) antagonizes MPP(+)-induced cytotoxicity in neuroblastoma cells and exerts neuroprotective effects against 6-hydroxydopamine (6-OHDA) and beta-amyloid-induced apoptosis of SH-SY5Y cells. In the present study we demonstrate that GUO protected C6 glioma cells, taken as a model system for astrocytes, from 6-OHDA-induced neurotoxicity.

Adenosine A1 receptor stimulation enhances osteogenic differentiation of human dental pulp-derived mesenchymal stem cells via WNT signaling.

In this study, mesenchymal stem cells deriving from dental pulp (DPSCs) of normal human impacted third molars, previously characterized for their ability to differentiate into osteoblasts, were used. We observed that: i) DPSCs, undifferentiated or submitted to osteogenic differentiation, express all four subtypes of adenosine receptors (AR) and CD73, corresponding to 5'-ecto-nucleotidase; and ii) AR stimulation with selective agonists elicited a greater osteogenic cell differentiation consequent to A1 receptor (A1R) activation. Therefore, we focused on the activity of this AR.

Wnt signaling behaves as a "master regulator" in the osteogenic and adipogenic commitment of human amniotic fluid mesenchymal stem cells.

Human amniotic fluid mesenchymal stem cells (huAFMSCs) are emerging as a promising therapeutic option in regenerative medicine. Here, we characterized huAFMSC phenotype and multipotentiality. When cultured in osteogenic medium, huAFMSC displayed a significant increase in: Alkaline Phosphatase (ALP) activity and mRNA expression, Alizarin Red S staining and Runx2 mRNA expression; whereas maintaining these cells in an adipogenic culture medium gave a time-dependent increase in PPARγ and FABP4 mRNA expression, glycerol-3-phosphate dehydrogenase (GPDH) activity and positivity to Oil Red Oil staining.

Guanine-based purines modulate the effect of L-NAME on learning and memory in rats.

Guanosine has been reported to exert neuroprotective effects. We recently reported that, following intraperitoneal (i.p.

Guanine-based purines modulate the effect of L-NAME on learning and memory in rats.

Guanosine has been reported to exert neuroprotective effects. We recently reported that, following intraperitoneal (i.p.

Tissue distribution and metabolism of guanosine in rats following intraperitoneal injection.

Guanosine has long been known as an endogenous purine nucleoside deeply involved in the modulation of several intracellular processes, especially G-protein activity. More recently, it has been reported to act as an extracellular signaling molecule released from neurons and, more markedly, from astrocytes either in basal conditions or after different kinds of stimulation including hypoxia. Moreover, in vivo studies have shown that guanosine plays an important role as both a neuroprotective and neurotrophic agent in the central nervous system.

Vascular endothelial growth factor enhances in vitro proliferation and osteogenic differentiation of human dental pulp stem cells.

Mesenchymal stem cells (MSC), isolated from dental tissues, are largely studied for future application in regenerative dentistry. In this study, we used MSC obtained from human dental pulp (DPSC) of normal impacted third molars that, when cultured in lineage-specific inducing media, differentiate into osteoblasts and adipocytes (evaluated by Alizarin Red S and Red Oil O stainings, respectively), thus showing a multipotency. We confirmed that DPSC, grown under undifferentiating conditions, are negative for hematopoietic (CD45, CD31, CD34, CD144) and positive for mesenchymal (CD29, CD90, CD105, CD166, CD146, STRO-1) markers, that underwent down-regulation when cells were grown in osteogenic medium for 3 weeks.

Altered distribution and function of A2A adenosine receptors in the brain of WAG/Rij rats with genetic absence epilepsy, before and after appearance of the disease.

The involvement of excitatory adenosine A(2A) receptors (A(2A)Rs), which probably contribute to the pathophysiology of convulsive seizures, has never been investigated in absence epilepsy. Here, we examined the distribution and function of A(2A)Rs in the brain of Wistar Albino Glaxo/Rijswijk (WAG/Rij) rats, a model of human absence epilepsy in which disease onset occurs 2-3 months after birth. In the cerebral areas that are mostly involved in the generation of absence seizures (somatosensory cortex, reticular and ventrobasal thalamic nuclei), A(2A)R density was lower in presymptomatic WAG/Rij rats than in control rats, as evaluated by immunohistochemistry and western blotting.

Guanosine improves motor behavior, reduces apoptosis, and stimulates neurogenesis in rats with parkinsonism.

Parkinson's disease (PD) is characterized by progressive degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNc) caused by an abnormal rate of apoptosis. Endogenous stem cells in the adult mammalian brain indicate an innate potential for regeneration and possible resource for neuroregeneration in PD. We previously showed that guanosine prevents apoptosis even when administered 48 hr after the toxin 1-methyl-4-phenylpyridinium (MPP(+)).

Changes in matrix extracellular phosphoglycoprotein expression before and during in vitro osteogenic differentiation of human dental papilla mesenchymal cells.

The purpose of this study is to characterise the expression of matrix extracellular phosphoglycoprotein (MEPE) in cultured mesenchymal cells isolated from human dental papilla (PaMCs) of impacted third molars either before or during differentiation of these cells into osteo/odontoblasts. PaMCs, like mesenchymal cells deriving from human dental pulp (DPMCs), resulted positive for a number of mesenchymal markers including CD146 and STRO-1. During the first week in culture they showed a faster proliferation rate than DPMCs, coupled to an earlier down-regulation of MEPE.

Non-adenine based purines accelerate wound healing.

Wound healing is a complex sequence of cellular and molecular processes that involves multiple cell types and biochemical mediators. Several growth factors have been identified that regulate tissue repair, including the neurotrophin nerve growth factor (NGF). As non-adenine based purines (NABPs) are known to promote cell proliferation and the release of growth factors, we investigated whether NABPs had an effect on wound healing.

Guanosine effect on cholesterol efflux and apolipoprotein E expression in astrocytes.

The main source of cholesterol in the central nervous system (CNS) is represented by glial cells, mainly astrocytes, which also synthesise and secrete apolipoproteins, in particular apolipoprotein E (ApoE), the major apolipoprotein in the brain, thus generating cholesterol-rich high density lipoproteins (HDLs). This cholesterol trafficking, even though still poorly known, is considered to play a key role in different aspects of neuronal plasticity and in the stabilisation of synaptic transmission. Moreover, cell cholesterol depletion has recently been linked to a reduction in amyloid beta formation.

Guanosine reduces apoptosis and inflammation associated with restoration of function in rats with acute spinal cord injury.

Spinal cord injury results in progressive waves of secondary injuries, cascades of noxious pathological mechanisms that substantially exacerbate the primary injury and the resultant permanent functional deficits. Secondary injuries are associated with inflammation, excessive cytokine release, and cell apoptosis. The purine nucleoside guanosine has significant trophic effects and is neuroprotective, antiapoptotic in vitro, and stimulates nerve regeneration.

MPP(+)-induced cytotoxicity in neuroblastoma cells: Antagonism and reversal by guanosine.

Guanosine exerts neuroprotective effects in the central nervous system. Apoptosis, a morphological form of programmed cell death, is implicated in the pathophysiology of Parkinson's disease (PD). MPP(+), a dopaminergic neurotoxin, produces in vivo and in vitro cellular changes characteristic of PD, such as cytotoxicity, resulting in apoptosis.

Activation of P2X(7) receptors stimulates the expression of P2Y(2) receptor mRNA in astrocytes cultured from rat brain.

Under pathological conditions brain cells release ATP at concentrations reported to activate P2X(7) ionotropic receptor subtypes expressed in both neuronal and glial cells. In the present study we report that the most potent P2X(7) receptor agonist BzATP stimulates the expression of the metabotropic ATP receptor P2Y(2) in cultured rat brain astrocytes. In other cell types several kinds of stimulation, including stress or injury, induce P2Y(2) expression that, in turn, is involved in different cell reactions.

Staurosporine-induced apoptosis in astrocytes is prevented by A1 adenosine receptor activation.

Astrocyte apoptosis occurs in acute and chronic pathological processes at the central nervous system and the prevention of astrocyte death may represent an efficacious intervention in protecting neurons against degeneration. Our research shows that rat astrocyte exposure to 100 nM staurosporine for 3h caused apoptotic death accompanied by caspase-3, p38 mitogen-ed protein kinase (MAPK) and glycogen synthase kinase-3beta (GSK3beta) activation. N(6)-chlorocyclopentyladenosine (CCPA, 2.

Molecular signalling mediating the protective effect of A1 adenosine and mGlu3 metabotropic glutamate receptor activation against apoptosis by oxygen/glucose deprivation in cultured astrocytes.

Astrocyte death may occur in neurodegenerative disorders and complicates the outcome of brain ischemia, a condition associated with high extracellular levels of adenosine and glutamate. We show that pharmacological activation of A(1) adenosine and mGlu3 metabotropic glutamate receptors with N(6)-chlorocyclopentyladenosine (CCPA) and (-)2-oxa-4-aminocyclo-[3.1.

Guanosine inhibits CD40 receptor expression and function induced by cytokines and beta amyloid in mouse microglia cells.

Growing evidence implicates CD40, a member of the TNFR superfamily, as contributing to the pathogenesis of many neurodegenerative diseases. Thus, strategies to suppress its expression may be of benefit in those disorders. To this aim, we investigated the effect of guanosine, a purine nucleoside that exerts neurotrophic and neuroprotective effects.

Endothelial cell anergy is mediated by bFGF through the sustained activation of p38-MAPK and NF-kappaB inhibition.

Tumors escape from immune surveillance by, among other mechanisms, the down- regulation of endothelial adhesion molecules, such as ICAM-1, and by unresponsiveness to inflammatory signals, a process mediated by angiogenic factors that is called endothelial cell anergy. Here we present the cell biological regulation of these processes. The angiogenic basic fibroblast growth factor (bFGF/FGF-2) was found to inhibit tumor necrosis factor-alpha (TNF-alpha)- induced elevation of ICAM-1, at transcriptional level.