170,011 research outputs found
Cholinergic effects mediated by M2 muscarinic receptor in human Schwann-like cells induced from adipose mesenchymal stem cells
No full textCholinergic effects mediated by M2 muscarinic receptor in human Schwann-like cells induced from adipose mesenchymal stem cells
Piovesana R.1,2, Faroni A.2, Tata AM1, Reid A.2
1Dept. Biol and Biotech. C. Darwin, University of Rome “Sapienza”, Rome, Italy;
2Blond McIndoe Lab, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK;
Schwann cells (SCs) have an important role in peripheral nerve regeneration but there are several restrictions on their clinical application. Adipose derived stem cells (ASCs) present good properties for cell therapies. When exposed to selective growth factors, they can acquire a SC-like phenotype (dASCs), expressing key SCs markers. Our group has demonstrated in rat model that M2 muscarinic receptor causes in vitro, a reversible arrest of cell proliferation, increasing SCs myelinating phenotype. Human dASCs, as rat dASCs, express muscarinic receptors. In the present work we evaluate if M2 muscarinic receptor activation may contribute to human dASCs proliferation and phenotype. M2 selective activation by selective agonist APE, causes a decreased cell proliferation, modulating the expression of gene involved in the proliferative state (i.e. c-jun and egr2) and neurotrophic factors. Although further analyses are needed to best characterise the role of M2 receptor, these data are the first evidence that its selective activation may have effects also on human dASCs proliferation and may favourite a neuroprotective environment relevant for nerve regeneration
Effects mediated by alpha7 nicotinic receptor in rat Schwann cells: implications in peripheral nerve regeneration
No full textPeripheral nerve fibers are able to regenerate. During nerve regeneration, Schwann cells (SCs) assume a phenotype known as Repair Schwann Cells, relevant for promoting an anti-inflammatory environment and axonal regeneration. SCs are cholinoceptive; in fact they express functional muscarinic cholinergic receptors favouring SCs differentiation towards myelinating phenotype (Loreti et al, 2007; Uggenti et al, 2014). Recently we have also characterized the expression of alpha7 nicotinic receptor. This receptor is fainlty expressed in sciatic nerve fibers and in SCs in vitro. Its expression significantly increases both in vivo and in vitro, after nerve injury or in presence of Bradykinin (Bk), a neuropeptide known for its pro-inflammatory effects. In fact we observed that sciatic nerve dissected and maintained in vitro for 24 hrs boh in absence or in presence of BK, showed a significant increase of alpha7 receptors. Moreover the selective activation of this receptor with (R)-ICH3 caused a modulation of uPA and MMPs responsible of the microenviroment modifications favouring Wallerian degeneration and promoting nerve regeneration. Similarly, the treatment of cultured SCs with BK appears to promote the repair Schwann cells phenotype, favouring the changing in cell morphology and up-regulating the expression of GFAP and c-jun. The activation of alpha7 receptor by selective agonist (R)-ICH3 after BK treatment, appears further promote this phenotype modulating inflammatory environment in terms of cytokines, growth factors and proteases production. These results suggest that alpha7 nicotinic receptor may be a cholinergic receptor expressed only by repair Schwann cells. Considering its anti-inflammatory role, alpha7 receptors may contribute to generate a microenviroment improving peripheral nerve regeneration. Loreti S., et al (2007) Neuron Glia Biology 3 : 269-279 Carolina Uggenti et al (2014). Dev. Neurobiol. 74:676-691 Piovesana R., et al (2018). J Cell Physiol. 233(7):5348-536
Liposome protein corona characterization as a new approach in nanomedicine
No full textThis trends article describes the analytical approaches for the in-depth characterization of the protein corona on liposome nanoparticles. In particular, examples since 2014 are summarized according to the analytical approach. Traditional protein corona characterizations from in vitro static experiments are provided along with the newly introduced experimental setups for characterization of the protein corona by in vitro dynamic and in vivo studies. Additionally, a special attention is also devoted to the need for introduction of new experimental workflows for characterization of a much wider array of biomolecules. In the most recent years, an extension of the protein corona concept to the biomolecular corona was introduced, and the analytical targets are no longer restricted to proteins, but to other important biomolecules as well, as they can potentially affect the biodistribution and interaction of nanoparticles with the biological systems. The few recent examples in this field are discussed for the characterization of metabolites and lipids in the biomolecular corona with examples, also extending the discussion from liposome to other types of nanoparticles. A final discussion is provided on the potential key role of the most recent omics approaches in the study of the nano-bio interface, with an overview on top-down proteomics, which allows a better elucidation of proteoforms, and on lipidomics and metabolomics, which allow a comprehensive untargeted characterization of lipids and metabolites, respectively. [Figure not available: see fulltext.]
New hydrophilic material based on hydrogel polymer for the selective enrichment of intact glycopeptides from serum protein digests
No full textThe paper describes the preparation and characterization of a new HILIC material for the enrichment of N-linked glycopeptides. The material was prepared using 2-acrylamido-2-methyl-1-propanesulfonic acid as the monomer and ethylene glycol dimethacrylate as the cross-linker. The material was developed by a Box-Behnken experimental design, taking into consideration the amount of monomer-to-crosslinker ratio, the composition, and the amount of porogen mixture. By this approach, the property of the resulting polymer could be fine-tuned to modulate the hydrophilicity and porosity. As HILIC enrichment is mostly dependent on hydrophilic interactions, including H-bonding, the amount of swelling was expected to have an important function, therefore the optimization considered a monomer percent in the range of 20–80%, which implied very different water swelling capacities. After assessing the potential of this new polymer family on fetuin digests, the 17 materials resulting from the Box-Behnken experimental design were used for the enrichment of glycopeptides from serum protein digests. The materials displayed a superior performance over cotton HILIC enrichment, both in terms of the number of enriched N-linked glycopeptides and selectivity, providing up to 762 N-linked glycopeptides with 77% selectivity. The optimization indicated that a high amount of monomer significantly affected the number of enriched glycopeptides, which is also closely connected with the hydrogel nature of the resulting polymers. The results not only provide one additional HILIC material for the enrichment of glycopeptides but also pave the way for the use and development of hydrogel materials for the enrichment of N-linked glycopeptides
Expression of acetylcholine nicotinic receptor a7 in rat Schwann cells: implication in nerve regeneration
No full textExpression of acetylcholine nicotinic receptor a7 in rat Schwann cells:
implication in nerve regeneration
Alessandro Matera1, R. Piovesana1, M. Taggi2, R. Canipari2, C. Dallanoce3, C. Fabrizi2, A. M.Tata1
1Dip. Biologia e Biotecnologie Charles Darwin, Sapienza , Università di Roma;
2Dipartimento SAIMLAL - Sapienza, Università di Roma; 3Dip. Di Scienze Farmaceutiche,
Sezione di Chimica Farmaceutica, Pietro Pratesi, Università di Milano
Peripheral Nervous System is able to regenerate. During regeneration, Schwann cells (SCs) assume a phenotype known as Repair Schwann Cells, relevant for promoting an anti-inflammatory environment and axonal regeneration. SCs are cholinoceptive and express muscarinic receptors. Recently, we have characterized the expression of α7 nicotinic receptor. Normally this receptor is fainlty expressed in SCs, as observed both in vivo and in vitro. Its expression significantly increased after nerve injury. In fact in presence of Bradykinin (Bk), a neuropeptide known for its pro-inflammatory effects, the expression of α7 significantly increased both in sciatic nerve fibers and in SCs in vitro. The treatment of cultured SCs with α7 selective agonist (R)-ICH3, after BK treatment, counteracts inflammatory environment in terms of cytokines, growth factors and proteases production, causing a decreased expression of TNFα and modulating tPA, uPA, and MMPs involved in the migration processes and growth factor production. These results suggest that α7 nicotinic receptor may be essential in the establishment of a microenvironment improving peripheral nerve regeneration
Effects mediated by alpha-7 nicotinic receptor in rat adipose mesenchymal stem cells
No full textMesenchymal stem cells (MSCs), are multipotent cells present in several tissues and organs as bone marrow and adipose tissue. MSCs derived from Adipose tissue (ASCs) are an attractive source for regenerative medicine because they can be easily isolated, rapidly expandable in culture and show excellent differentiation potential. Acetylcholine (ACh), the most important neurotransmitter in central (CNS) and peripheral nervous system (PNS), plays a key role in the control of physiological processes also in non-neural tissues. Previously demonstrated that M2 muscarinic receptors negatively modulate ASC proliferation and migration. In the present work we demonstrate that rat ASCs also express α7 nAChR receptors. By using the selective α7 nicotinic receptor agonist ICH-3, we demonstrated that α7 receptor activation causes a reduction of cell proliferation without affecting cell survival and morphology. Moreover, by wound healing assay, we have also demonstrated that α7 promotes cell migration and a significant upregulation of CXCR4 receptor. Interestingly the activation of α7 nAChR appears also up-regulate the expression of M2 acetylcholine receptor, suggesting a feedback positive loop between muscarinic and nicotinic receptors. Our data suggest that ACh, via cholinergic receptors might contribute to modulate ASC physiology. Moreover, in particular via nicotinic receptors, ACh might control ASCs migration
Muscarinic receptor activation modulates neurotrophic factors production in rat Schwann-like cells derived from adipose mesenchymal stem cells.
No full textMuscarinic receptor activation modulates neurotrophic factors production in rat Schwann-like cells derived from adipose mesenchymal stem cells
Piovesana R1, Faroni A2, Soligo M3, Manni L3, Reid AJ2 & Tata AM1
1Dept. Biol and Biotech. C. Darwin, University of Rome “Sapienza”, Rome, Italy; 2Blond McIndoe Lab, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK; 3Institute of Translational Pharmacology-CNR, Rome, Italy
Peripheral nerve injury is commonly caused by direct mechanical trauma. Regeneration depends on the ability of Schwann cells (SCs) to create a favourable environment, by producing neurotrophic factors. Although SCs are effective in promoting nerve regeneration, they are not a convenient source of transplantable cells to improve outcomes after injury. Mesenchymal Stem Cells derived from adipose tissue (ASCs) seem to be a promising alternative source considering their ability to differentiate towards SC phenotype (Schwann-like).
SCs express different receptors for neurotransmitters. In particular cholinergic stimulation of M2 muscarinic receptor decreases SCs proliferation whilst upregulating myelination. Previously, we demonstrated that Schwann-like cells express muscarinic receptors; in particular the M2 receptor activation resulted in decreased proliferation and reduced migration.
In present work, we have characterised the effects mediated by muscarinic receptors on neurotrophic factors (NFs) expression and production. The selective activation of M2 receptors by arecaidine propargyl ester (APE) caused a significant decrease of the transcript levels for NFs (NGF, BDNF and GDNF), while the non-selective agonist muscarine did not influence NFs mRNA expression. By custom made Elisa Assay, we analysed the production of two different NGF forms, precursor (proNGF) and mature NGF (mNGF). APE treatment induced a decreased release of both NGF forms, whereas muscarine treatment stimulated an increased release of mNGF. Western blot analysis indicated that both agonists caused a significant decrease in the expression of the proNGF isoform at 25 kDa, which is likely involved in the modulation of apoptotic processes.
The data obtained suggest a relevant role of muscarinic receptors in the modulation of NFs production in Schwann-like cells. In particular the ability of both muscarinic agonists to negatively modulate the proNGF isoform, thereby suggesting a neuroprotective role of muscarinic receptors towards regenerating axons
Determination of Enantioselectivity and Enantiomeric Excess by Mass Spectrometry in the Absence of Chiral Chromatographic Separation: An Overview
No full textThis review describes the principles and instrumentation for the screening of asymmetric reactions by mass spectrometry. These techniques witnessed a significant advancement in the last few years. Although some of them are still at the proof-of-concept development stage, several applications might be foreseen in the field of combinatorial, high-throughput parallel catalyst screening
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