TY - JOUR AU - Kormos, József AU - Daróczi, Lajos AU - Szöllősi, János AU - Mátyus, László AU - Jenei, Attila TI - Novel Transmission Electron Microscopic Method to Quantify Protein Clustering on the Cell Surface JF - CURRENT PROTOCOLS J2 - CURR PROT VL - 4 PY - 2024 IS - 5 PG - 14 SN - 2691-1299 DO - 10.1002/cpz1.1045 UR - https://m2.mtmt.hu/api/publication/34913707 ID - 34913707 AB - The cell surface distribution patterns (clustering) of membrane proteins have been widely investigated in cell biology. Here we describe a novel transmission electron microscopic (TEM) protocol designed to improve the quality of information obtained about the protein distribution patterns detected. This novel method makes it possible to study the clustering of all transmembrane proteins on one half of the cytoplasmic membrane of a whole cell. To achieve better imaging, we combine various methods, including critical‐point drying, fixation of gold beads with a carbon layer, and a newly developed chemical thinning method. In addition, in our image‐processing algorithm, we implemented pair correlation and pair cross‐correlation functions, providing more details and better quantitative accuracy in characterizing the size and numbers of possible protein clusters. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC. LA - English DB - MTMT ER - TY - JOUR AU - Kormos, József AU - Veres, Adrienn J. AU - Imre, László AU - Mátyus, László AU - Benkő, Szilvia AU - Szöllősi, János AU - Jenei, Attila TI - HLA DQ protein changes the cell surface distribution pattern of HLA proteins as monitored by Förster resonance energy transfer and high-resolution electron microscopy JF - CYTOMETRY PART A J2 - CYTOM PART A VL - 103 PY - 2023 IS - 12 SP - 978 EP - 991 PG - 14 SN - 1552-4922 DO - 10.1002/cyto.a.24787 UR - https://m2.mtmt.hu/api/publication/34129378 ID - 34129378 N1 - Early View Department of Biophysics and Cell Biology, Faculty of Dentistry, University of Debrecen, Debrecen, Hungary Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary ELKH-DE Cell Biology and Signaling Research Group (Eötvös Loránd Research Network-University of Debrecen), Faculty of Medicine, University of Debrecen, Debrecen, Hungary Department of Basic Medical Sciences, Faculty of Dentistry, University of Debrecen, Debrecen, Hungary Export Date: 15 September 2023 CODEN: CPAYA Correspondence Address: Jenei, A.; Department of Biophysics and Cell Biology, Egyetem tér 1, Hungary; email: jenei@edu.unideb.hu AB - Peptide presentation by MHC class I and MHC class II molecules plays important roles in the regulation of the immune response. One factor in these displays is the density of antigen, which must exceed a critical threshold for the effective activation of T cells. Nonrandom distribution of MHC class I and class II has already been detected at the nanometer level and at higher hierarchical levels. It is not clear how the absence and reappearance of some protein molecules can influence the nonrandom distribution. Therefore, we performed experiments on HLA II‐deficient bare lymphocyte syndrome (BLS1) cells: we created a stable transfected cell line, tDQ6‐BLS‐1, and were able to detect the effect of the appearance of HLA‐DQ6 molecules on the homo and heteroassociation of different cell surface molecules by comparing Förster resonance energy transfer (FRET) efficiency on transfected cells to that on nontransfected BLS‐1 and JY human B‐cell lines. Our FRET results show a decrease in homoassociation FRET between HLA I chains in HLA‐DQ6‐transfected tDQ6‐BLS‐1 cells compared with the parent BLS‐1 cell line and an increase in heteroassociation FRET between HLA I and HLA II (compared with JY cells), suggesting a similar pattern of antigen presentation by the HLA‐DQ6 allele. Transmission electron microscopy (TEM) revealed that both HLA class I and class II molecules formed clusters at higher hierarchical levels on the tDQ6‐BLS‐1 cells, and the de novo synthesized HLA DQ molecules did not intersperse with HLA class I islands. These observations could be important in understanding the fine tuning of the immune response. LA - English DB - MTMT ER - TY - JOUR AU - Hrubi, Edit AU - Imre, László AU - Robaszkiewicz, A AU - Virág, László AU - Kerenyi, F AU - S. Nagy, Krisztina AU - Varga, Gábor AU - Jenei, Attila AU - Hegedűs, Csaba TI - Diverse effect of BMP-2 homodimer on mesenchymal progenitors of different origin JF - HUMAN CELL: THE OFFICIAL JOURNAL OF THE JAPAN HUMAN CELL SOCIETY J2 - HUM CELL VL - 31 PY - 2018 IS - 2 SP - 139 EP - 148 PG - 10 SN - 0914-7470 DO - 10.1007/s13577-018-0202-5 UR - https://m2.mtmt.hu/api/publication/3352923 ID - 3352923 N1 - Faculty of Dentistry, University of Debrecen, Nagyerdei krt. 98, Debrecen, 4012, Hungary Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem tér 1, Debrecen, 4032, Hungary Department of General Biophysics, Institute of Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, Lodz, 90-236, Poland Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Egyetem tér 1, Debrecen, 4032, Hungary Department of Oral Biology, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary Cited By :21 Export Date: 29 September 2024 Correspondence Address: Hrubi, E.; Faculty of Dentistry, Nagyerdei krt. 98, Hungary; email: hrubi.edit@dental.unideb.hu AB - Bone morphogenetic protein-2 (BMP-2), is a potential factor to enhance osseointegration of dental implants. However, the appropriate cellular system to investigate the osteogenic effect of BMP-2 in vitro in a standardized manner still needs to be defined. The aim of this study was to examine the effect of BMP-2 on the cell proliferation and osteogenic differentiation of human osteogenic progenitors of various origins: dental pulp stem cells (DPSC), human osteosarcoma cell line (Saos-2) and human embryonic palatal mesenchymal cell line (HEPM). For induction of osteogenic differentiation, cell culture medium was supplemented with BMP-2 homodimer alone or in combination with conventionally used differentiation inducing agents. Differentiation was monitored for 6-18 days. To assess differentiation, proliferation rate, alkaline phosphatase activity, calcium deposition and the expression level of osteogenic differentiation marker genes (Runx2, BMP-2) were measured. BMP-2 inhibited cell proliferation in a concentration and time-dependent manner. In a concentration which caused maximal cell proliferation, BMP-2 did not induce osteogenic differentiation in any of the tested systems. However, it had a synergistic effect with the osteoinductive medium in both DPSC and Saos-2, but not in HEPM cells. We also found that the differentiation process was faster in Saos-2 than in DPSCs. Osteogenic differentiation could not be induced in the osteoblast progenitor HEPM cells. Our data suggest that in a concentration that inhibits proliferation the differentiation inducing effect of BMP-2 is evident only in the presence of permissive osteoinductive components. beta-glycerophosphate, was identified interacting with BMP-2 in a synergistic manner. LA - English DB - MTMT ER - TY - JOUR AU - Rente, Tünde AU - Bakó, József AU - Bágyi, Kinga, Ágnes AU - Jenei, Attila AU - Hegedűs, Csaba TI - A fogászatban alkalmazható keresztkötött hialuronsav alapú hidrogélrendszerek szintézise és hatóanyag leadásának vizsgálata JF - FOGORVOSI SZEMLE J2 - FOGORV SZLE VL - 110 PY - 2017 IS - 3 SP - 82 EP - 87 PG - 6 SN - 0015-5314 DO - 10.33891/FSZ.110.3.82-87 UR - https://m2.mtmt.hu/api/publication/3278641 ID - 3278641 LA - Hungarian DB - MTMT ER - TY - GEN AU - Rente, Tünde AU - Jenei, Attila AU - Hegedűs, Csaba TI - Béta-trikálcium-foszfát (ß-TCP) funkcionális tulajdonságainak javítása hiarulonsav alapú hidrogél alkalmazásával ET - 0 PY - 2017 SP - 31 UR - https://m2.mtmt.hu/api/publication/30326167 ID - 30326167 LA - Hungarian DB - MTMT ER - TY - GEN AU - Rente, Tünde AU - Jenei, Attila AU - Hegedűs, Csaba TI - A Kalcium szerepe a csontregeneráció szabályozásában ET - 0 PY - 2016 SP - 79 UR - https://m2.mtmt.hu/api/publication/30330184 ID - 30330184 LA - Hungarian DB - MTMT ER - TY - JOUR AU - Shrestha, Dilip AU - Jenei, Attila AU - Nagy, Péter AU - Vereb, György AU - Szöllősi, János TI - Understanding FRET as a research tool for cellular studies JF - INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES J2 - INT J MOL SCI VL - 16 PY - 2015 IS - 4 SP - 6718 EP - 6756 PG - 39 SN - 1661-6596 DO - 10.3390/ijms16046718 UR - https://m2.mtmt.hu/api/publication/2871115 ID - 2871115 N1 - Funding Agency and Grant Number: Hungarian Scientific Research FundOrszagos Tudomanyos Kutatasi Alapprogramok (OTKA) [NK 101337, K103906]; European CommissionEuropean CommissionEuropean Commission Joint Research Centre [(LSHC-CT-2005-018914)-ATTACK, MCRTN-CT-2006-036946-2]; New Hungary Development Plan - European Social FundEuropean Social Fund (ESF); European Regional Development FundEuropean Commission [TAMOP-4.2.2.A-11/1/KONV-2012-0025, TAMOP-4.2.2-08/1-2008-0019, TAMOP-4.2.1/B-09/1/KONV-2010-007]; Baross Gabor Program [REG-EA-09-1-2009-0010] Funding text: We are thankful to the financial support from the Hungarian Scientific Research Fund (NK 101337, K103906); the European Commission grants (LSHC-CT-2005-018914)-ATTACK, MCRTN-CT-2006-036946-2 (IMMUNANOMAP), the New Hungary Development Plan co-financed by the European Social Fund and the European Regional Development Fund (TAMOP-4.2.2.A-11/1/KONV-2012-0025, TAMOP-4.2.2-08/1-2008-0019, TAMOP-4.2.1/B-09/1/KONV-2010-007) and the Baross Gabor Program (REG-EA-09-1-2009-0010). LA - English DB - MTMT ER - TY - JOUR AU - Shrestha, D AU - Exley, MA AU - Vereb, György AU - Szöllősi, János AU - Jenei, Attila TI - CD1d favors MHC neighborhood, GM1 ganglioside proximity and low detergent sensitive membrane regions on the surface of B lymphocytes JF - BIOCHIMICA ET BIOPHYSICA ACTA-GENERAL SUBJECTS J2 - BBA-GEN SUBJECTS VL - 1840 PY - 2014 IS - 1 SP - 667 EP - 680 PG - 14 SN - 0304-4165 DO - 10.1016/j.bbagen.2013.10.030 UR - https://m2.mtmt.hu/api/publication/2495610 ID - 2495610 AB - Background: Cluster of differentiation 1 (CD1) represents a family of proteins which is involved in lipid-based antigen presentation. Primarily, antigen presenting cells, like B cells, express CD1 proteins. Here, we examined the cell-surface distribution of CD1d, a subtype of CD1 receptors, on B lymphocytes. Methods: Fluorescence labeling methods, including fluorescence resonance energy transfer (FRET), were employed to investigate plasma membrane features of CD1d receptors. Results: High FRET efficiency was observed between CD1d and MHC I heavy chain (MHC I-HC), β2-microglobulin (β2m) and MHC II proteins in the plasma membrane. In addition, overexpression of CD1d reduced the expression of MHC II and increased the expression of MHC I-HC and β2m proteins on the cell-surface. Surprisingly, β2m dependent CD1d isoform constituted only ~ 15% of the total membrane CD1d proteins. Treatment of B cells with methyl-β-cyclodextrin (MβCD) / simvastatin caused protein rearrangement; however, FRET demonstrated only minimal effect of these chemicals on the association between CD1d and GM1 ganglioside on cell-surface. Likewise, a modest effect was only observed in a co-culture assay between MβCD/simvastatin treated C1R-CD1d cells and invariant natural killer T cells on measuring secreted cytokines (IFNγ and IL4). Furthermore, CD1d rich regions were highly sensitive to low concentration of Triton X-100. Physical proximity between CD1d, MHC and GM1 molecules was also detected in the plasma membrane. Conclusions: An intricate relationship between CD1d, MHC, and lipid species was found on the membrane of human B cells. General significance: Organization of CD1d on the plasma membrane might be critical for its biological functions. © 2013 Elsevier B.V. All rights reserved. LA - English DB - MTMT ER - TY - JOUR AU - Kuttor, A AU - Szalóki, Melinda AU - Rente, Tünde AU - Kerényi, Farkas AU - Bakó, József AU - Fábián, István AU - Lázár, István AU - Jenei, Attila AU - Hegedűs, Csaba TI - Preparation and application of highly porous aerogel-based bioactive materials in dentistry JF - FRONTIERS OF MATERIALS SCIENCE J2 - FRONT MATER SCI VL - 8 PY - 2014 IS - 1 SP - 46 EP - 52 PG - 7 SN - 2095-025X DO - 10.1007/s11706-014-0231-2 UR - https://m2.mtmt.hu/api/publication/2564008 ID - 2564008 AB - In this study, the possibility of preparation and application of highly porous silica aerogel-based bioactive materials are presented. The aerogel was combined with hydroxyapatite and β-tricalcium phosphate as bioactive and osteoinductive agents. The porosity of aerogels was in the mesoporous region with a maximum pore diameter of 7.4 and 12.7 nm for the composite materials. The newly developed bioactive materials were characterized by scanning electron microscopy. The in vitro biological effect of these modified surfaces was also tested on SAOS-2 osteogenic sarcoma cells by confocal laser scanning microscopy. © 2014 Higher Education Press and Springer-Verlag Berlin Heidelberg. LA - English DB - MTMT ER - TY - GEN AU - Rente, Tünde AU - Jenei, Attila AU - Hegedűs, Csaba TI - A kalcium- foszfát (CaP) szerepe a hatékony csontregenerációra ET - 0 PY - 2014 SP - 39 UR - https://m2.mtmt.hu/api/publication/30332573 ID - 30332573 LA - Hungarian DB - MTMT ER -