Osteoporosis and sarcopenia are diseases of aging that frequently occur together and reduce quality of life in the elderly population. Evidence is emerging for signaling crosstalk between bone and muscle via circulating and local mediators, leading to the concept that muscle-bone crosstalk may coordinate age- related degenerative changes. An exciting new paradigm in cell-cell communication is that extracellular vesicles (EV) (exosomes and microvesicles) may provide a novel mechanism for communication between cells. It has also been proposed that circulating muscle-derived exosomes (termed ?exersomes?) may mediate some of the beneficial effects of exercise in the body. EV are membrane-bound particles shed from cells with a cargo of proteins, mRNAs and microRNAs (miRNAs). The EV dock with a target cell, delivering their cargo and altering its function. We have shown that young and aged osteocytes shed EV, which may provide a novel mechanism for regulation of osteoblast function. Live cell imaging suggests osteocytes shed EV from their cell body and dendrites and may shed them into the circulation. Osteocyte EV are taken up by osteoblasts and myoblasts and have potent effects on osteoblasts to promote differentiation towards an early osteocyte phenotype. EV from myoblasts and myotubes are taken up by osteocytes and induce ?-catenin signaling. These findings lead to our overall hypothesis that extracellular vesicles (EV) are important regulators of bone and muscle cell function and provide a novel mechanism for crosstalk between muscle and bone that may regulate age-related osteoporosis and sarcopenia. This hypothesis will be tested using complimentary in vitro and in vivo approaches and using intravital imaging in young and aged mouse models with fluorescent reporters to tag bone and muscle cells.
Aim 1 will determine the role of EV in regulating osteocyte-osteoblast reciprocal interactions in vitro and in vivo and how this is altered by aging and exercise. This will be done using EV from osteoblast and osteocyte cell lines and primary cells to determine EV effects on the differentiated function of the reciprocal cell type.
Aim 2 will determine the role of EV in regulating muscle-bone crosstalk and how it is altered by aging and exercise. This will be done using EV from myoblast, osteoblast and osteocyte cell lines and primary cells to determine EV effects on the differentiated function of the reciprocal cell types. In both aims, live cell and intravital imaging will determine the kinetics of EV release and uptake in muscle and bone cells in vitro and in vivo. Young and aged mouse models will be used with and without wheel running exercise to determine in vitro and in vivo the effect of aging and exercise on EV release, composition and function. These studies may result in paradigm shifting insight into the mechanisms of molecular crosstalk between bone and muscle and will pave the way for exploiting the potential of muscle and bone derived EVs as circulating biomarkers and as novel therapeutics for age related bone and muscle loss.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Program Projects (P01)
Project #
5P01AG039355-08
Application #
9934996
Study Section
Special Emphasis Panel (ZAG1)
Project Start
Project End
Budget Start
2020-06-01
Budget End
2021-05-31
Support Year
8
Fiscal Year
2020
Total Cost
Indirect Cost
Name
Indiana University-Purdue University at Indianapolis
Department
Type
DUNS #
603007902
City
Indianapolis
State
IN
Country
United States
Zip Code
46202
Bonewald, Lynda (2018) Use it or lose it to age: A review of bone and muscle communication. Bone 120:212-218
Kitase, Yukiko; Vallejo, Julian A; Gutheil, William et al. (2018) ?-aminoisobutyric Acid, l-BAIBA, Is a Muscle-Derived Osteocyte Survival Factor. Cell Rep 22:1531-1544
Pin, Fabrizio; Barreto, Rafael; Kitase, Yukiko et al. (2018) Growth of ovarian cancer xenografts causes loss of muscle and bone mass: a new model for the study of cancer cachexia. J Cachexia Sarcopenia Muscle 9:685-700
Morris, Josephine L; Cross, Stephen J; Lu, Yinhui et al. (2018) Live imaging of collagen deposition during skin development and repair in a collagen I - GFP fusion transgenic zebrafish line. Dev Biol 441:4-11
Begonia, Mark; Dallas, Mark; Johnson, Mark L et al. (2017) Comparison of strain measurement in the mouse forearm using subject-specific finite element models, strain gaging, and digital image correlation. Biomech Model Mechanobiol 16:1243-1253
Tiede-Lewis, LeAnn M; Xie, Yixia; Hulbert, Molly A et al. (2017) Degeneration of the osteocyte network in the C57BL/6 mouse model of aging. Aging (Albany NY) 9:2190-2208
Wang, Zhiying; Bian, Liangqiao; Mo, Chenglin et al. (2017) Targeted quantification of lipid mediators in skeletal muscles using restricted access media-based trap-and-elute liquid chromatography-mass spectrometry. Anal Chim Acta 984:151-161
Jähn, Katharina; Kelkar, Shilpa; Zhao, Hong et al. (2017) Osteocytes Acidify Their Microenvironment in Response to PTHrP In Vitro and in Lactating Mice In Vivo. J Bone Miner Res 32:1761-1772
Huang, Jian; Romero-Suarez, Sandra; Lara, Nuria et al. (2017) Crosstalk between MLO-Y4 osteocytes and C2C12 muscle cells is mediated by the Wnt/?-catenin pathway. JBMR Plus 1:86-100
Bonewald, Lynda F (2017) The Role of the Osteocyte in Bone and Nonbone Disease. Endocrinol Metab Clin North Am 46:1-18

Showing the most recent 10 out of 39 publications