13 results on '"Chiritoiu M"'
Search Results
2. Antimicrobial polycaprolactone/polyethylene glycol embedded lysozyme coatings of Ti implants for osteoblast functional properties in tissue engineering
- Author
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Visan, A., Cristescu, R., Stefan, N., Miroiu, M., Nita, C., Socol, M., Florica, C., Rasoga, O., Zgura, I., Sima, L.E., Chiritoiu, M., Chifiriuc, M.C., Holban, A.M., Mihailescu, I.N., and Socol, G.
- Published
- 2017
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3. COENOTAXONOMICAL CHARACTERIZATION OF THE MEGAFORBS FROM HOROABA VALLEY (BUCEGI MOUNTAINS)
- Author
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CHIRIŢOIU MAGDALENA
- Subjects
megaforbs ,Horoaba Canyon ,Plant culture ,SB1-1110 ,Botany ,QK1-989 - Abstract
In this paper are presented two associations of megaforbs of Adenostylo-Doronicetum austriaci Horv. 1956 and Cirsio waldsteinii-Heracleetum transsilvanici Pawl. et Walas 1949, which were identified in the area of the Natural Reserve Peştera-Cocora-Valea Horoabei (Bucegi Natural Parc). There are also presented the species of plants found here and which are included in the Red List of the superior plants from Romania.
- Published
- 2008
4. Chemokine (C-X-C motif) ligand 1 (CXCL1) and chemokine (C-X-C motif) ligand 2 (CXCL2) modulate the activity of TRPV1+/IB4+ cultured rat dorsal root ganglia neurons upon short-term and acute application
- Author
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Deftu, A. F., Filippi, A., Koji Shibasaki, Gheorghe, R. O., Chiritoiu, M., and Ristoiu, V.
5. Targeting EDEM protects against ER stress and improves development and survival in C. elegans.
- Author
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Ghenea S, Chiritoiu M, Tacutu R, Miranda-Vizuete A, and Petrescu SM
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- Animals, Endoplasmic Reticulum genetics, Endoplasmic Reticulum metabolism, Glycoproteins metabolism, Membrane Proteins metabolism, Caenorhabditis elegans genetics, Caenorhabditis elegans metabolism, Protein Folding
- Abstract
EDEM-1, EDEM-2 and EDEM-3 are key players for the quality control of newly synthesized proteins in the endoplasmic reticulum (ER) by accelerating disposal and degradation of misfolded proteins through ER Associated Degradation (ERAD). Although many previous studies reported the role of individual ERAD components especially in cell-based systems, still little is known about the consequences of ERAD dysfunction under physiological and ER stress conditions in the context of a multicellular organism. Here we report the first individual and combined characterization and functional interplay of EDEM proteins in Caenorhabditis elegans using single, double, and triple mutant combinations. We found that EDEM-2 has a major role in the clearance of misfolded proteins from ER under physiological conditions, whereas EDEM-1 and EDEM-3 roles become prominent under acute ER stress. In contrast to SEL-1 loss, the loss of EDEMs in an intact organism induces only a modest ER stress under physiological conditions. In addition, chronic impairment of EDEM functioning attenuated both XBP-1 activation and up-regulation of the stress chaperone GRP78/BiP, in response to acute ER stress. We also show that pre-conditioning to EDEM loss in acute ER stress restores ER homeostasis and promotes survival by activating ER hormesis. We propose a novel role for EDEM in fine-tuning the ER stress responsiveness that affects ER homeostasis and survival., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2022
- Full Text
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6. Proteomics of regenerated tissue in response to a titanium implant with a bioactive surface in a rat tibial defect model.
- Author
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Boteanu RM, Suica VI, Ivan L, Safciuc F, Uyy E, Dragan E, Croitoru SM, Grumezescu V, Chiritoiu M, Sima LE, Vlagioiu C, Socol G, and Antohe F
- Subjects
- Actins chemistry, Animals, Biopolymers, Cell Adhesion, Cell Proliferation, Coated Materials, Biocompatible chemistry, Computational Biology, Fracture Healing drug effects, Male, Mass Spectrometry, Mesenchymal Stem Cells, Microscopy, Fluorescence, Osseointegration drug effects, Prosthesis Design, Proteomics, Rats, Rats, Wistar, Surface Properties, Bone Regeneration drug effects, Prostheses and Implants, Tibia physiopathology, Titanium chemistry
- Abstract
Due to their excellent mechanical and biocompatibility properties, titanium-based implants are successfully used as biomedical devices. However, when new bone formation fails for different reasons, impaired fracture healing becomes a clinical problem and affects the patient's quality of life. We aimed to design a new bioactive surface of titanium implants with a synergetic PEG biopolymer-based composition for gradual delivery of growth factors (FGF2, VEGF, and BMP4) during bone healing. The optimal architecture of non-cytotoxic polymeric coatings deposited by dip coating under controlled parameters was assessed both in cultured cells and in a rat tibial defect model (100% viability). Notably, the titanium adsorbed polymer matrix induced an improved healing process when compared with the individual action of each biomolecules. High-performance mass spectrometry analysis demonstrated that recovery after a traumatic event is governed by specific differentially regulated proteins, acting in a coordinated response to the external stimulus. Predicted protein interactions shown by STRING analysis were well organized in hub-based networks related with response to chemical, wound healing and response to stress pathways. The proposed functional polymer coatings of the titanium implants demonstrated the significant improvement of bone healing process after injury.
- Published
- 2020
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7. Silencing the Cytoskeleton Protein Iba1 (Ionized Calcium Binding Adapter Protein 1) Interferes with BV2 Microglia Functioning.
- Author
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Gheorghe RO, Deftu A, Filippi A, Grosu A, Bica-Popi M, Chiritoiu M, Chiritoiu G, Munteanu C, Silvestro L, and Ristoiu V
- Subjects
- Animals, Cell Adhesion, Cell Count, Cell Line, Cell Movement, Cell Proliferation, Leukocyte Common Antigens metabolism, Mice, Opsonin Proteins metabolism, Phagocytosis, RNA, Small Interfering metabolism, Receptors, Purinergic P2X7 metabolism, Reproducibility of Results, Zymosan metabolism, Calcium-Binding Proteins metabolism, Cytoskeletal Proteins metabolism, Gene Silencing, Microfilament Proteins metabolism, Microglia metabolism
- Abstract
Iba1 (ionized calcium binding adapter protein 1) is a cytoskeleton protein specific only for microglia and macrophages, where it acts as an actin-cross linking protein. Although frequently regarded as a marker of activation, its involvement in cell migration, membrane ruffling, phagocytosis or in microglia remodeling during immunological surveillance of the brain suggest that Iba1 is not a simple cytoskeleton protein, but a signaling molecule involved in specific signaling pathways. In this study we investigated if Iba1 could also represent a drug target, and tested the hypothesis that its specific silencing with customized Iba1-siRNA can modulate microglia functioning. The results showed that Iba1-silenced BV2 microglia migrate less due to reduced proliferation and cell adhesion, while their phagocytic activity and P2x7 functioning was significantly increased. Our data are the proof of concept that Iba1 protein is a new microglia target, which opens a new therapeutic avenue for modulating microglia behavior.
- Published
- 2020
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8. EDEM1 Drives Misfolded Protein Degradation via ERAD and Exploits ER-Phagy as Back-Up Mechanism When ERAD Is Impaired.
- Author
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Chiritoiu M, Chiritoiu GN, Munteanu CVA, Pastrama F, Ivessa NE, and Petrescu SM
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- Autophagy genetics, Endoplasmic Reticulum metabolism, Endoplasmic Reticulum-Associated Degradation genetics, HEK293 Cells, HeLa Cells, Humans, Mass Spectrometry, Proteasome Endopeptidase Complex genetics, Protein Aggregates genetics, Protein Folding, Endoplasmic Reticulum genetics, Membrane Proteins genetics, Protein Interaction Maps genetics, Proteolysis
- Abstract
Endoplasmic reticulum (ER)-associated degradation (ERAD) is the main mechanism of targeting ER proteins for degradation to maintain homeostasis, and perturbations of ERAD lead to pathological conditions. ER-degradation enhancing α-mannosidase-like (EDEM1) was proposed to extract terminally misfolded proteins from the calnexin folding cycle and target them for degradation by ERAD. Here, using mass-spectrometry and biochemical methods, we show that EDEM1 is found in auto-regulatory complexes with ERAD components. Moreover, the N-terminal disordered region of EDEM1 mediates protein-protein interaction with misfolded proteins, whilst the absence of this domain significantly impairs their degradation. We also determined that overexpression of EDEM1 can induce degradation, even when proteasomal activity is severely impaired, by promoting the formation of aggregates, which can be further degraded by autophagy. Therefore, we propose that EDEM1 maintains ER homeostasis and mediates ERAD client degradation via autophagy when either dislocation or proteasomal degradation are impaired.
- Published
- 2020
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9. Long-Term Evaluation of Dip-Coated PCL-Blend-PEG Coatings in Simulated Conditions.
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Visan AI, Popescu-Pelin G, Gherasim O, Mihailescu A, Socol M, Zgura I, Chiritoiu M, Elena Sima L, Antohe F, Ivan L, Vranceanu DM, M Cotruț C, Cristescu R, and Socol G
- Abstract
Our study focused on the long-term degradation under simulated conditions of coatings based on different compositions of polycaprolactone-polyethylene glycol blends (PCL-blend-PEG), fabricated for titanium implants by a dip-coating technique. The degradation behavior of polymeric coatings was evaluated by polymer mass loss measurements of the PCL-blend-PEG during immersion in SBF up to 16 weeks and correlated with those yielded from electrochemical experiments. The results are thoroughly supported by extensive compositional and surface analyses (FTIR, GIXRD, SEM, and wettability investigations). We found that the degradation behavior of PCL-blend-PEG coatings is governed by the properties of the main polymer constituents: the PEG solubilizes fast, immediately after the immersion, while the PCL degrades slowly over the whole period of time. Furthermore, the results evidence that the alteration of blend coatings is strongly enhanced by the increase in PEG content. The biological assessment unveiled the beneficial influence of PCL-blend-PEG coatings for the adhesion and spreading of both human-derived mesenchymal stem cells and endothelial cells., Competing Interests: The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
- Published
- 2020
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10. GRASP55 and UPR Control Interleukin-1β Aggregation and Secretion.
- Author
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Chiritoiu M, Brouwers N, Turacchio G, Pirozzi M, and Malhotra V
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- Animals, Caspase 1 genetics, DNA-Binding Proteins genetics, Endoplasmic Reticulum drug effects, Endoplasmic Reticulum genetics, Lipopolysaccharides pharmacology, Macrophages drug effects, Macrophages metabolism, Mice, Mice, Knockout, Unfolded Protein Response genetics, eIF-2 Kinase antagonists & inhibitors, Endoribonucleases genetics, Golgi Matrix Proteins genetics, Interleukin-1beta genetics, Protein Aggregates genetics, Protein Serine-Threonine Kinases genetics, eIF-2 Kinase genetics
- Abstract
Signal-sequence-lacking interleukin (IL)-1β, is cleaved by caspase-1 to mature mIL-1β, which is secreted, without entering the endoplasmic reticulum. We report that macrophages of GRASP55
-/- mice are defective in mIL-1β secretion and retain it as intracellular aggregates. Intriguingly, GRASP55-/- macrophages are defective in the IRE1α branch of the unfolded protein response. This finding fits well with our data that inhibition of IRE1α also impairs mIL-1β secretion and causes its accumulation in intracellular aggregates. PERK inhibition, on the other hand, controls caspase-1-mediated conversion of proIL-1β to mIL-1β. These findings reveal translation-independent functions of PERK and IRE1α: PERK controls the production of mIL-1β, which is then followed by GRASP55 and IRE1α activity to keep mIL-1β in a secretion-competent form., (Copyright © 2019 Elsevier Inc. All rights reserved.)- Published
- 2019
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11. Unconventional secretion of FABP4 by endosomes and secretory lysosomes.
- Author
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Villeneuve J, Bassaganyas L, Lepreux S, Chiritoiu M, Costet P, Ripoche J, Malhotra V, and Schekman R
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- 3T3-L1 Cells, Animals, Cells, Cultured, Mice, Mice, Inbred C57BL, Secretory Pathway, Endosomes metabolism, Fatty Acid-Binding Proteins metabolism, Lysosomes metabolism
- Abstract
An appreciation of the functional properties of the cytoplasmic fatty acid binding protein 4 (FABP4) has advanced with the recent demonstration that an extracellular form secreted by adipocytes regulates a wide range of physiological functions. Little, however, is known about the mechanisms that mediate the unconventional secretion of FABP4. Here, we demonstrate that FABP4 secretion is mediated by a membrane-bounded compartment, independent of the conventional endoplasmic reticulum-Golgi secretory pathway. We show that FABP4 secretion is also independent of GRASP proteins, autophagy, and multivesicular bodies but involves enclosure within endosomes and secretory lysosomes. We highlight the physiological significance of this pathway with the demonstration that an increase in plasma levels of FABP4 is inhibited by chloroquine treatment of mice. These findings chart the pathway of FABP4 secretion and provide a potential therapeutic means to control metabolic disorders associated with its dysregulated secretion., (© 2018 Villeneuve et al.)
- Published
- 2018
- Full Text
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12. Chemokine (C-X-C motif) ligand 1 (CXCL1) and chemokine (C-X-C motif) ligand 2 (CXCL2) modulate the activity of TRPV1+/IB4+ cultured rat dorsal root ganglia neurons upon short-term and acute application.
- Author
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Deftu AF, Filippi A, Shibsaki K, Gheorghe RO, Chiritoiu M, and Ristoiu V
- Subjects
- Animals, Calcium physiology, Capsaicin pharmacology, Cells, Cultured, Ganglia, Spinal cytology, HEK293 Cells, Humans, Male, Neurons drug effects, Pruritus physiopathology, Rats, Wistar, Receptors, Interleukin-8B genetics, TRPV Cation Channels antagonists & inhibitors, Chemokine CXCL1 physiology, Chemokine CXCL2 physiology, Ganglia, Spinal physiology, Neurons physiology, TRPV Cation Channels physiology
- Abstract
CXCL1 and CXCL2 are two chemokines with 78% homology of their sequence. CXCL1 was associated with atopic dermatitis, a highly pruritic skin disease, but it is not clear what is its mechanism of action, while for CXCL2 there are no data about an association with itch sensitivity. CXCL1 and CXCL2 can modulate TRPV1 receptors, which are one of the most important downstream effectors for itch sensitivity, upon short-term (4 h) or long-term (24 h) incubation, but the data are incomplete. Therefore, the aims of this study were to better characterize the short-term effects of CXCL1 and CXCL2 on TRPV1
+ /IB4+ dorsal root ganglia neurons known to include nociceptor and itch-sensitive neurons, and to obtain new data about the acute application (12 min) of the two chemokines on the same population of neurons. The results showed that 4 nM CXCL1 and 3.6 nM CXCL2 significantly reduce TRPV1 desensitization in TRPV1+ /IB4+ DRG+ neurons after short-term incubation, but when acutely applied CXCL1 activated a sub-population of itch-sensitive TRPV1+ /IB4+ cells in a slow, low amplitude manner, while CXCL2 had a similar effect but on non-itch TRPV1+ /IB4+ DRG neurons. These data contribute to a better understanding of CXCL1 and CXCL2 mechanism of action for both pain and itch inducing effects.- Published
- 2017
13. Laser deposition of poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) - lysozyme microspheres based coatings with anti-microbial properties.
- Author
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Grumezescu V, Holban AM, Sima LE, Chiritoiu MB, Chiritoiu GN, Grumezescu AM, Ivan L, Safciuc F, Antohe F, Florica C, Luculescu CR, Chifiriuc MC, and Socol G
- Subjects
- Cells, Cultured, Humans, Lasers, Microscopy, Electron, Scanning, Microspheres, Muramidase pharmacology, Polyesters pharmacology, Polyethylene Glycols chemistry, Anti-Infective Agents pharmacology, Drug Delivery Systems, Muramidase chemistry, Polyesters chemistry
- Abstract
The purpose of this study was to obtain, characterize and evaluate the cytotoxicity and antimicrobial activity of coatings based on poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) - Lysozyme (P(3HB-3HV)/Lys) and P(3HB-3HV) - Polyethylene glycol - Lysozyme (P(3HB-3HV)/PEG/Lys) spheres prepared by Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique, in order to obtain functional and improved Ti-based implants. Morphological investigation of the coatings by Infrared Microscopy (IRM) and SEM revealed that the average diameter of P(3HB-3HV)/Lys spheres is around 2μm and unlike the drop cast samples, IRM recorded on MAPLE films revealed a good distribution of monitored functional groups on the entire scanned surface. The biological evaluation of MAPLE structured surfaces revealed an improved biocompatibility with respect to osteoblasts and endothelial cells as compared with Ti substrates and an enhanced anti-biofilm effect against Gram positive (Staphylococcus aureus) and Gram negative (Pseudomonas aeruginosa) tested strains. Thus, we propose that the fabricated P(3HB-3HV)/PEG/Lys and P(3HB-3HV)/Lys microspheres may be efficiently used as a matrix for controlled local drug delivery, with practical applications in developing improved medical surfaces for the reduction of implant-associated infections., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
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