http://hdl.handle.net/10027/7326 Tue, 21 May 2013 06:33:20 GMT 2013-05-21T06:33:20Z http://hdl.handle.net/10027/8733 Mammalian Masticatory Muscles: Homology, Nomenclature, and Diversification Druzinsky, Robert E.; Doherty, Alison H.; De Vree, Frits L. There is a deep and rich literature of comparative studies of jaw muscles in mammals but no recent analyses employ modern phylogenetic techniques to better understand evolutionary changes that have occurred in these muscles. In order to fully develop and utilize the Feeding Experiments End-user Database (FEED), we are constructing a comprehensive ontology of mammalian jaw muscles. This process has led to a careful consideration of nomenclature and homologies of the muscles and their constituent parts. Precise determinations of muscle attachments have shown that muscles with similar names are not necessarily homologous. Using new anatomical descriptions derived from the literature, we defined character states for the jaw muscles in diverse mammalian species. We then mapped those characters onto a recent phylogeny of mammals with the aid of the Mesquite software package. Our data further elucidate how muscle groups associated with the feeding apparatus differ and have become highly specialized in certain mammalian orders, such as Rodentia, while remaining conserved in other orders. We believe that careful naming of muscles and statistical analyses of their distributions among mammals, in association with the FEED database, will lead to new, significant insights into the functional, structural, and evolutionary morphology of the jaw muscles. This is a pre-copy-editing, author-produced PDF of an article accepted for publication inJournal of Biological Chemistry following peer review. The definitive publisher-authenticated versionDruzinsky RE, Doherty AH, De Vree FL. Mammalian masticatory muscles: homology, nomenclature, and diversification. Integr Comp Biol. 2011 Aug;51(2):224-34. doi: 10.1093/icb/icr067. DOI: 10.1093/icb/icr067 Mon, 01 Aug 2011 05:00:00 GMT http://hdl.handle.net/10027/8733 2011-08-01T05:00:00Z http://hdl.handle.net/10027/7818 Activation of the ERK1/2 Mitogen-Activated Protein Kinase Cascade by Dentin Matrix Protein 1 Promotes Osteoblast Differentiation Eapen, Asha S.; Ramachandran, Amsaveni; Pratap, Jitesh; George, Anne DMP1 has been shown to play many roles in osteogenesis. We recently demonstrated that calcium-mediated stress kinase activation by DMP1 leads to osteoblast differentiation. In this study we demonstrate that DMP1 can also activate the extracellular signal-regulated kinase (ERK)-MAPK pathway. This activation was mediated through the RGD integrin-binding domain in DMP1. Further, we demonstrate that Runx2, an essential transcription factor, is stimulated by the ERK-MAPK pathway. Copyright © 2011 S. Karger AG, Basel Post print version of article may differ from published version. The definitive version is available through Karger at DOI: 10.1159/000324258 [http://content.karger.com/ProdukteDB/produkte.asp?doi=10.1159/000324258]. © 2011 S. Karger AG, Basel Fri, 06 May 2011 05:00:00 GMT http://hdl.handle.net/10027/7818 2011-05-06T05:00:00Z http://hdl.handle.net/10027/7772 Successful Periodontal Ligament Regeneration by Periodontal Progenitor Preseeding on Natural Tooth Root Surfaces Dangaria, Smit J.; Ito, Yoshihiro; Luan, Xianghong; Diekwisch, Thomas G.H. The regeneration of lost periodontal ligament (PDL) and alveolar bone is the purpose of periodontal tissue engineering. The goal of the present study was to assess the suitability of 3 odontogenic progenitor populations from dental pulp, PDL, and dental follicle for periodontal regeneration when exposed to natural and synthetic apatite surface topographies. We demonstrated that PDL progenitors featured higher levels of periostin and scleraxis expression, increased adipogenic and osteogenic differentiation potential, and pronounced elongated cell shapes on barren root chips when compared with dental pulp and dental follicle cells. When evaluating the effect of surface characteristics on PDL progenitors, natural root surfaces resulted in elongated PDL cell shapes, whereas PDL progenitors on synthetic apatite surfaces were rounded or polygonal. In addition, surface coatings affected PDL progenitor gene expression profiles: collagen I coatings enhanced alkaline phosphatase and osteocalcin expression levels and laminin-1 coatings increased epidermal growth factor (EGF), nestin, cadherin 1, and keratin 8 expression. PDL progenitors seeded on natural tooth root surfaces in organ culture formed new periodontal fibers after 3 weeks of culture. Finally, replantation of PDL progenitor-seeded tooth roots into rat alveolar bone sockets resulted in the complete formation of a new PDL and stable reattachment of teeth over a 6-month period. Together, these findings indicate that periodontal progenitor cell type as well as mineral surface topography and molecular environment play crucial roles in the regeneration of true periodontal anchorage. This is a copy of an article published in the Stem Cells and Development. © 2011 [copyright Mary Ann Liebert, Inc.]; Stem Cells and Development is available online at: http://www.liebertonline.com. The original version is available through Mary Ann Liebert at DOI: 10.1089/scd.2010.0431 Wed, 09 Mar 2011 06:00:00 GMT http://hdl.handle.net/10027/7772 2011-03-09T06:00:00Z http://hdl.handle.net/10027/7373 Protein templates in hard tissue engineering George, Anne; Ravindran, Sriram Biomineralization processes such as formation of bones and teeth require controlled mineral deposition and self-assembly into hierarchical biocomposites with unique mechanical properties. Ideal biomaterials for regeneration and repair of hard tissues must be biocompatible, possess micro and macroporosity for vascular invasion, provide surface chemistry and texture that facilitate cell attachment, proliferation, differentiation of lineage specific progenitor cells, and induce deposition of calcium phosphate mineral. To expect in vivo like cellular response several investigators have used extracellular matrix proteins as templates to recreate in vivo microenvironment for the regeneration of hard tissues. Several novel methods of designing tissue repair and restoration materials using bioinspired strategies are currently being formulated. Nanoscale structured materials can be fabricated via the spontaneous organization of self-assembling proteins to construct hierarchically organized nanomaterials. The advantage of such a method is that polypeptides can be specifically designed as building blocks incorporated with molecular recognition features and spatially distributed bioactive ligands that would provide a physiological environment for cells in vitro and in vivo. This is a rapidly evolving area and provides a promising platform for future development of nanostructured templates for hard tissue engineering. In this review we try to highlight the importance of proteins as templates for regeneration and repair of hard tissues as well as the potential of peptide based nanomaterials for regenerative therapies. Post print version of article may differ from published version. The definitive version is available through Elsevier at DOI: 10.1016/j.nantod.2010.05.005 Sun, 01 Aug 2010 05:00:00 GMT http://hdl.handle.net/10027/7373 2010-08-01T05:00:00Z