Adult mesenchymal progenitor cells have enormous potential for use in reparative medicine. The easy access and isolation of bone marrow aspirate or liposuction collection have made these cells a prime target for studies of differentiation into various adult mesenchymal tissues for regenerative purposes. If this source of progenitor cells is to achieve broad clinical utility, the true identity of the progenitors and its progeny need to be more precisely defined and modulation of their commitment needs to be understood. Obstacles to these goals are the inability to identify and purify these cells, and the lack of in vivo markers that can be used to confirm that progenitor cells can attain the state and functionality of terminally differentiated phenotypes. We accept these challenges and propose a hypothesis that will test if pericyte/myofibroblasts have the characteristics of mesenchymal progenitors. We hypothesize that smooth muscle a-actin (SMA) expressing cells are the major source of osteoprogenitors in adult bone tissue. To define a population of myofibroblasts/pericytes we will utilize previously developed transgenic mice in which pericytes are identified by SMA promoter-GFP transgene expression (SMAGFP). The differentiation ability of these cells, will be tested using transgenic mice in which osteoblast, adipocyte or chondrocyte specific promoters drive GFP reporter expression. These transgenes activate at mature stages of the lineage and, by combining complementary colors, we can test for the ability of isolated SMA+ cells to progress from a progenitor to fully mature state. In addition we will complete lineage tracing experiments using regeneration models and new bone formation in vivo. Utilizing an SMA-CreERT2 mouse crossed with a Rosa26(cag-tdTomato) reporter line in models of tissue repair that include fracture healing and induction of osteogenic potential using ectopic bone formation induced by BMP2, we will evaluate the progenitor ability of SMA expressing cells. In the third aim we propose to determine the divergence point of mesenchymal progenitor cell into mature lineages. Based on expression of lineage-directed GFP markers, stage specific populations of mesenchymal progenitors will be isolated and their differentiation ability will be tested. Defining the control of differentiation will allow for the understanding of the mechanisms that direct mesenchymal stem cells down the osteoprogenitor lineage. Completion of the proposed studies will provide a better understanding of the identity and the phenotype of the mesenchymal progenitor cells as well as provide information on their active role in bone healing during injury and bone fractures.

Public Health Relevance

The aims of this application are focused to better identification and characterization of adult mesenchymal progenitor cells. Our study will evaluate their ability to differentiate into mature mesenchymal lineages in vitro and in vivo and determine the diverging point at which mesenchymal progenitor cells commit to mature lineages and factors that can modulate this commitment. The knowledge developed in this grant will provide the foundation for future studies aimed at use of mesenchymal progenitor cells as therapeutic tools for osteoporosis and genetic disorders of bone.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Project (R01)
Project #
5R01AR055607-03
Application #
8442384
Study Section
Skeletal Biology Development and Disease Study Section (SBDD)
Program Officer
Wang, Fei
Project Start
2011-02-01
Project End
2015-01-31
Budget Start
2013-02-01
Budget End
2014-01-31
Support Year
3
Fiscal Year
2013
Total Cost
$326,599
Indirect Cost
$112,849
Name
University of Connecticut
Department
Dentistry
Type
Schools of Dentistry
DUNS #
022254226
City
Farmington
State
CT
Country
United States
Zip Code
06030
Wee, Natalie K Y; Sinder, Benjamin P; Novak, Sanja et al. (2018) Skeletal phenotype of the neuropeptide Y knockout mouse. Neuropeptides :
Gr?evi?, Danka; Sironi, Marina; Valentino, Sonia et al. (2018) The Long Pentraxin 3 Plays a Role in Bone Turnover and Repair. Front Immunol 9:417
Aravamudhan, Aja; Ramos, Daisy M; Nip, Jonathan et al. (2018) Micro-Nanostructures of Cellulose-Collagen for Critical Sized Bone Defect Healing. Macromol Biosci 18:
Matsumoto, Kei; Xavier, Sandhya; Chen, Jun et al. (2017) Instructive Role of the Microenvironment in Preventing Renal Fibrosis. Stem Cells Transl Med 6:992-1005
Matthews, Brya G; Roeder, Emilie; Wang, Xi et al. (2017) Splenomegaly, myeloid lineage expansion and increased osteoclastogenesis in osteogenesis imperfecta murine. Bone 103:1-11
Vidovic, I; Banerjee, A; Fatahi, R et al. (2017) ?SMA-Expressing Perivascular Cells Represent Dental Pulp Progenitors In Vivo. J Dent Res 96:323-330
Vidovic Zdrilic, I; de Azevedo Queiroz, I O; Matthews, B G et al. (2017) Mineral trioxide aggregate improves healing response of periodontal tissue to injury in mice. J Periodontal Res 52:1058-1067
Sagomonyants, K; Kalajzic, I; Maye, P et al. (2017) FGF Signaling Prevents the Terminal Differentiation of Odontoblasts. J Dent Res 96:663-670
Matthews, Brya G; Torreggiani, Elena; Roeder, Emilie et al. (2016) Osteogenic potential of alpha smooth muscle actin expressing muscle resident progenitor cells. Bone 84:69-77
Matic, Igor; Matthews, Brya G; Wang, Xi et al. (2016) Quiescent Bone Lining Cells Are a Major Source of Osteoblasts During Adulthood. Stem Cells 34:2930-2942

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