Substrate deformation levels associated with routine physical activity are less stimulatory to bone cells relative to loading-induced oscillatory fluid flow

J. You, Clare E Yellowley-genetos, H. J. Donahue, Y. Zhang, Q. Chen, C. R. Jacobs

Research output: Contribution to journalArticle

248 Citations (Scopus)

Abstract

Although it is well accepted that bone tissue metabolism is regulated by external mechanical loads, it remains unclear to what load-induced physical signals bone cells respond. In this study, a novel computer-controlled stretch device and parallel plate flow chamber were employed to investigate cytosolic calcium (Ca2+(i)) mobilization in response to a range of dynamic substrate strain levels (0.1-10 percent, 1 Hz) and oscillating fluid flow (2 N/m2, 1 Hz). In addition, we quantified the effect of dynamic substrate strain and oscillating fluid flow on the expression of mRNA for the bone matrix protein osteopontin (OPN). Our data demonstrate that continuum strain levels observed for routine physical activities (<0.5 percent) do not induce Ca2+ (i) responses in osteoblastic cells in vitro. However, there was a significant increase in the number of responding cells at larger strain levels. Moreover, we found no change in osteopontin mRNA level in response to 0.5 percent strain at 1 Hz. In contrast, oscillating fluid flow predicted to occur in the lacunar-canalicular system due to routine physical activities (2 N/m2, 1 Hz) caused significant increases in both Ca2+(i) and OPN mRNA. These data suggest that, relative to fluid flow, substrate deformation may play less of a role in bone cell mechanotransduction associated with bone adaptation to routine loads.

Original languageEnglish (US)
Pages (from-to)387-393
Number of pages7
JournalJournal of Biomechanical Engineering
Volume122
Issue number4
DOIs
StatePublished - 2000
Externally publishedYes

Fingerprint

Osteopontin
Flow of fluids
Bone
Bone and Bones
Substrates
Messenger RNA
Bone Matrix
Metabolism
Cell Count
Calcium
Equipment and Supplies
Tissue
Proteins

ASJC Scopus subject areas

  • Biophysics
  • Biomedical Engineering

Cite this

Substrate deformation levels associated with routine physical activity are less stimulatory to bone cells relative to loading-induced oscillatory fluid flow. / You, J.; Yellowley-genetos, Clare E; Donahue, H. J.; Zhang, Y.; Chen, Q.; Jacobs, C. R.

In: Journal of Biomechanical Engineering, Vol. 122, No. 4, 2000, p. 387-393.

Research output: Contribution to journalArticle

@article{a5c7efddd4034a398cb2922aac3ff293,
title = "Substrate deformation levels associated with routine physical activity are less stimulatory to bone cells relative to loading-induced oscillatory fluid flow",
abstract = "Although it is well accepted that bone tissue metabolism is regulated by external mechanical loads, it remains unclear to what load-induced physical signals bone cells respond. In this study, a novel computer-controlled stretch device and parallel plate flow chamber were employed to investigate cytosolic calcium (Ca2+(i)) mobilization in response to a range of dynamic substrate strain levels (0.1-10 percent, 1 Hz) and oscillating fluid flow (2 N/m2, 1 Hz). In addition, we quantified the effect of dynamic substrate strain and oscillating fluid flow on the expression of mRNA for the bone matrix protein osteopontin (OPN). Our data demonstrate that continuum strain levels observed for routine physical activities (<0.5 percent) do not induce Ca2+ (i) responses in osteoblastic cells in vitro. However, there was a significant increase in the number of responding cells at larger strain levels. Moreover, we found no change in osteopontin mRNA level in response to 0.5 percent strain at 1 Hz. In contrast, oscillating fluid flow predicted to occur in the lacunar-canalicular system due to routine physical activities (2 N/m2, 1 Hz) caused significant increases in both Ca2+(i) and OPN mRNA. These data suggest that, relative to fluid flow, substrate deformation may play less of a role in bone cell mechanotransduction associated with bone adaptation to routine loads.",
author = "J. You and Yellowley-genetos, {Clare E} and Donahue, {H. J.} and Y. Zhang and Q. Chen and Jacobs, {C. R.}",
year = "2000",
doi = "10.1115/1.1287161",
language = "English (US)",
volume = "122",
pages = "387--393",
journal = "Journal of Biomechanical Engineering",
issn = "0148-0731",
publisher = "American Society of Mechanical Engineers(ASME)",
number = "4",

}

TY - JOUR

T1 - Substrate deformation levels associated with routine physical activity are less stimulatory to bone cells relative to loading-induced oscillatory fluid flow

AU - You, J.

AU - Yellowley-genetos, Clare E

AU - Donahue, H. J.

AU - Zhang, Y.

AU - Chen, Q.

AU - Jacobs, C. R.

PY - 2000

Y1 - 2000

N2 - Although it is well accepted that bone tissue metabolism is regulated by external mechanical loads, it remains unclear to what load-induced physical signals bone cells respond. In this study, a novel computer-controlled stretch device and parallel plate flow chamber were employed to investigate cytosolic calcium (Ca2+(i)) mobilization in response to a range of dynamic substrate strain levels (0.1-10 percent, 1 Hz) and oscillating fluid flow (2 N/m2, 1 Hz). In addition, we quantified the effect of dynamic substrate strain and oscillating fluid flow on the expression of mRNA for the bone matrix protein osteopontin (OPN). Our data demonstrate that continuum strain levels observed for routine physical activities (<0.5 percent) do not induce Ca2+ (i) responses in osteoblastic cells in vitro. However, there was a significant increase in the number of responding cells at larger strain levels. Moreover, we found no change in osteopontin mRNA level in response to 0.5 percent strain at 1 Hz. In contrast, oscillating fluid flow predicted to occur in the lacunar-canalicular system due to routine physical activities (2 N/m2, 1 Hz) caused significant increases in both Ca2+(i) and OPN mRNA. These data suggest that, relative to fluid flow, substrate deformation may play less of a role in bone cell mechanotransduction associated with bone adaptation to routine loads.

AB - Although it is well accepted that bone tissue metabolism is regulated by external mechanical loads, it remains unclear to what load-induced physical signals bone cells respond. In this study, a novel computer-controlled stretch device and parallel plate flow chamber were employed to investigate cytosolic calcium (Ca2+(i)) mobilization in response to a range of dynamic substrate strain levels (0.1-10 percent, 1 Hz) and oscillating fluid flow (2 N/m2, 1 Hz). In addition, we quantified the effect of dynamic substrate strain and oscillating fluid flow on the expression of mRNA for the bone matrix protein osteopontin (OPN). Our data demonstrate that continuum strain levels observed for routine physical activities (<0.5 percent) do not induce Ca2+ (i) responses in osteoblastic cells in vitro. However, there was a significant increase in the number of responding cells at larger strain levels. Moreover, we found no change in osteopontin mRNA level in response to 0.5 percent strain at 1 Hz. In contrast, oscillating fluid flow predicted to occur in the lacunar-canalicular system due to routine physical activities (2 N/m2, 1 Hz) caused significant increases in both Ca2+(i) and OPN mRNA. These data suggest that, relative to fluid flow, substrate deformation may play less of a role in bone cell mechanotransduction associated with bone adaptation to routine loads.

UR - http://www.scopus.com/inward/record.url?scp=0033804637&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0033804637&partnerID=8YFLogxK

U2 - 10.1115/1.1287161

DO - 10.1115/1.1287161

M3 - Article

VL - 122

SP - 387

EP - 393

JO - Journal of Biomechanical Engineering

JF - Journal of Biomechanical Engineering

SN - 0148-0731

IS - 4

ER -