Osteoclast-Derived Exosomes

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Material Information

Title:
Osteoclast-Derived Exosomes Novel Regulators of Bone Remodeling and Markers of Resorption
Physical Description:
1 online resource (12 p.)
Language:
english
Creator:
Le, Nancy Huynh
Publisher:
University of Florida
Place of Publication:
Gainesville, Fla.
Publication Date:

Thesis/Dissertation Information

Degree:
Master's ( M.S.)
Degree Grantor:
University of Florida
Degree Disciplines:
Dental Sciences, Dentistry
Committee Chair:
HOLLIDAY,LEXIE SHANNON
Committee Co-Chair:
DOLCE,CALOGERO
Committee Members:
MCHUGH,KEVIN

Subjects

Subjects / Keywords:
exosome -- orthodontics -- osteoclast -- remodeling -- resorption
Dentistry -- Dissertations, Academic -- UF
Genre:
Dental Sciences thesis, M.S.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract:
Introduction: Histologic studies reveal that 90% of orthodontically treated teeth have root resorption. Radiographic techniques are significantly less sensitive and require additional radiation exposure to the patient. Therefore, non-invasive methods of screening for root resorption will prove highly useful in the field of orthodontics. Recently, our group found that approximately 54% of proteins detected in gingival crevicular fluid (GCF) are exosome proteins. Exosomes are 30-100 nm vesicles that have been shown to be secreted by many mammalian cells and are involved in intercellular communication. To date, there have been no published findings of osteoclast-derived exosomes. We hypothesized that osteoclasts secrete exosomes, and the composition of these exosomes change based on the activation state of the osteoclasts. We further hypothesized that osteoclast-derived exosomes are involved in bone remodeling. Methods: Osteoclasts were grown from mouse marrow or RAW 264.7 cells by treatment with recombinant RANKL and CSF-1. Bone slices were labeled with biotin using NHS-LC-biotin. Exosomes were isolated using published protocols. We used transmission electron microscopy and antibodies against the exosome markers CD63 and EpCAM to detect exosomes. Antibodies against subunits of vacuolar proton-ATPase (V-ATPase) were used to examine differences in exosomes secreted by active vs. inactive osteoclasts. We tested the biologic activity of osteoclast-derived exosomes by counting TRAP-positive giant cells with and without the addition of exosomes. Results: Immunoblots confirmed the presence of CD63 and EpCAM. Transmission electron microscopy revealed numerous vesicles of 30-100nm. The E- and a3-subunits of V-ATPase appeared in exosome fractions from active osteoclasts and not in exosomes from inactive osteoclasts. Exosomes from osteoclasts resorbing biotinylated bone slices contained biotinylated peptides. Exosome-treated cultures had significantly increased counts of TRAP+ giant cells (73% more) compared with untreated cultures. Conclusions: Osteoclasts produce exosomes that change in composition when osteoclasts become activated. These exosomes carry the ability to stimulate osteoclast differentiation. We hope that future studies will prove the value of osteoclast-derived exosomes as novel diagnostic tools for bone and/or root resorption, and perhaps as molecular nanodevices for regulating orthodontic tooth movement.
General Note:
In the series University of Florida Digital Collections.
General Note:
Includes vita.
Bibliography:
Includes bibliographical references.
Source of Description:
Description based on online resource; title from PDF title page.
Source of Description:
This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility:
by Nancy Huynh Le.
Thesis:
Thesis (M.S.)--University of Florida, 2014.
Local:
Adviser: HOLLIDAY,LEXIE SHANNON.
Local:
Co-adviser: DOLCE,CALOGERO.
Electronic Access:
RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2015-05-31

Record Information

Source Institution:
UFRGP
Rights Management:
Applicable rights reserved.
Classification:
lcc - LD1780 2014
System ID:
UFE0046446:00001