Fogorvosi szemle, 2005 (98. évfolyam, 1-6. szám)
2005-04-01 / 2. szám
83 FOGORVOSI SZEMLE T. VANDEN BŐS Experimental Periodontology, Academic Center for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, The Netherlands QUANTITATIVE 2D-ELECTROPHORESIS: A NEW PROMISING TECHNIQUE In addition to the study of mRNA levels in cells/tissues, which give an indication of their capacity to synthesize proteins, the determination of the actual expression of proteins is important. 2D-electrophoresis is a technique, which can be applied to that purposeand has been used for years. Recently, several fluorescent dyes were developed by Amerham Biosciences, which can be used to label proteins before they are applied to isoelectrophocusing and electrophoresis. It is now even possible to label 3 different protein mixtures with 3 different dyes and to apply these at one and the same 2D-gel. Differences in labeling intensities of the protein spots can be quantitated using a sensitive laser scanner (Typhoon) and specialized software (DeCyder). Proteins of interest can then be identified by MALDI-tof mass spectrometry. Since a half-year we have now experience with this technique. In this presentation examples will be given of the possibilities of this new technique. Acknowledgement: The support of COSTB23 is acknowledged. GY. VEREB Department of Biophysics and Cell Biology, Medical and Health Science Center, University of Debrecen, H- 4012 Debrecen, Hungary MODERN MICROSCOPIC APPROACHES IN THE INVESTIGATION OF MOLECULAR INTERACTIONS The incredibly fast development of genomics and proteimics in the past few years has shed light on hundreds of molecule pairs that, at least in vitro, can interact with each other. Whether these interactions actually take place in situ, in the living cell, can rarely be stated with certainty. However, it is obvious that these interactions are critical both in maintaining the stable resting state of cells and in implementing their activation processes that yield proper (or pathological) responses to external and internal signals. Modern microscopy, biophysical approaches and digital signal processing can provide information on these in situ molecular interactions in a space and time-dependent manner. Three levels of infor■ 98. évf. 2. sz. 2005. mation can be retrieved: (i) colocalization on the microscopic scale, (ii) static molecular interactions in supramolecular complexes, and (iii) dynamic co-diffusion of molecules. Relevant approaches will be discussed in detail: (i) calculating spatial auto and crosscorrelation in high resolution microscopic images, (ii) assessing fluorescence resonance energy transfer with subcellular resolution, and (iii) fluorescence correlation and cross-correlation spectroscopy. References: Brock R, Vámosi G, Vereb G, Jovin TM. (1999). Proc Natl Acad Sci USA 96:10123-28.; Vereb G, Matkó J, Vámosi G, Ibrahim SM, et al. (2000). Proc Natl Acad Sei USA 97:6013-8.; Vereb G, Szöllősi J, Matkó J, Nagy P, et al. (2003). Proc Natl Acad Sei USA 100:8053- 58.; Vereb G, Matkó J, Szöllősi J. (2004) Methods in Cell Biology 75:105-149. Key words: in situ molecular interactions, FRET, correlation microscopy/spectroscopy. Acknowledgement: Supported by OTKA T37831, ETT 532/2003, OM Békésy Fellowship and COST Action B23. H. YAMAMOTO, S. CHO*, E. KIM*, J-Y. KIM*, Y. KOZAWA, H-S. JUNG* Department of Anatomy II, Nihon University School of Dentistry at Matsudo, Chiba, Japan, ‘Department of Oral Biology, College of Dentistry, Yonsei University, Seoul, Korea. DEVELOPMENTAL STUDIES ON THE HERTWIG’S EPITHELIAL ROOT SHEATH IN MICE Hertwig’s epithelial root sheath (HERS) plays an important role in tooth root formation. Root formation of the first molar from mice was examined in this study, which focused on cell proliferation, cell death, cell migration j and the expression patterns of the signaling molecules, proteins between PN8 to PN26 by immunohistochemistry, TUNEL staining, Di.l. tracing and in situ hybridization. The number of HERS cells decreased during root formation, although HERS retained length until PN15. HERS cells did not migrate during root formation. Moreover, the immunopositive reaction of laminin beta-3 and syndecan-1 in HERS indicates that both cell adhesion and cell proliferation are essential for HERS development. Bmp-2, Bmp-4 and Msx-2 were expressed in HERS cells during root formation, although Msx-1 was not detected. This study also developed an in-vitro culture system for investigating the periodontium, and suggests for understanding of the periodontium fully exploring development and regeneration. Our results provide a comprehensive model describing the morphogenesis of the early root development in mice. Keywords: Hertwig’s epithelial root sheath, root formation, mice.
