Substrate curvature sensing through Myosin IIa upregulates early osteogenesis

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

Topographical cues mimicking the extracellular matrix (ECM) have demonstrated control over a diverse range of cellular behaviours including: initial adhesion, migration, cell growth, differentiation and death. How cells sense, and in turn translate, the topographical cues remains to be answered, but likely involves interactions through interfacial forces that influence cytoskeletal structure and integrin clustering, leading to the downstream activity of intracellular signalling cascades. Electrospun fibers have shown significant success as a biomimetic topography for bone tissue engineering applications, but mechanisms by which osteoprogenitor cells translate the fiber geometry into intracellular signalling activity is only recently being examined. We hypothesized that increased cellular differentiation observed on fibrous topography is due to acto-myosin contractility and cellular stiffness via the small GTPase RhoA. In order to evaluate this hypothesis, MC3T3-E1 osteoprogenitor cells were grown on poly(methyl methacrylate) (PMMA) fibers of 1.153 ± 0.310 μm diameter. The elastic modulus of the cell surface was measured by atomic force microscopy (AFM) with a colloidal probe. Overall cellular stiffness was found to increase more than three-fold in osteoprogenitors adhered to a fiber, as opposed to those grown on a flat substrate. Pharmacological inhibition of RhoA signalling activity decreased cellular stiffness and cytoskeletal integrity of osteoprogenitors growing on fibrous substrates. Finally, we demonstrated not only RhoA activity through its effector Rho-associated coiled coil kinase II (ROCKII), but also Myosin IIa promotes early osteogenic differentiation, as shown by alkaline phosphatase (ALP) staining. Previous studies have demonstrated the importance of ROCKII on early differentiation. Our results shed light on mechanisms underlying geometry sensing by highlighting the role of Myosin IIa in addition to ROCKII and could ultimately contribute to scaffold design strategies.

Original languageEnglish (US)
Pages (from-to)1407-1416
Number of pages10
JournalIntegrative Biology (United Kingdom)
Volume5
Issue number11
DOIs
StatePublished - Jan 1 2013

Fingerprint

Myosins
Osteogenesis
rho-Associated Kinases
Up-Regulation
Fibers
pioglitazone
Stiffness
Substrates
Topography
Cues
Myosin Type II
Biomimetics
Surface Tension
Monomeric GTP-Binding Proteins
Geometry
Atomic Force Microscopy
Elastic Modulus
Cell growth
Polymethyl Methacrylate
Tissue Engineering

All Science Journal Classification (ASJC) codes

  • Biophysics
  • Biochemistry

Cite this

@article{c833757fd3a243358be0a35f4b5566e4,
title = "Substrate curvature sensing through Myosin IIa upregulates early osteogenesis",
abstract = "Topographical cues mimicking the extracellular matrix (ECM) have demonstrated control over a diverse range of cellular behaviours including: initial adhesion, migration, cell growth, differentiation and death. How cells sense, and in turn translate, the topographical cues remains to be answered, but likely involves interactions through interfacial forces that influence cytoskeletal structure and integrin clustering, leading to the downstream activity of intracellular signalling cascades. Electrospun fibers have shown significant success as a biomimetic topography for bone tissue engineering applications, but mechanisms by which osteoprogenitor cells translate the fiber geometry into intracellular signalling activity is only recently being examined. We hypothesized that increased cellular differentiation observed on fibrous topography is due to acto-myosin contractility and cellular stiffness via the small GTPase RhoA. In order to evaluate this hypothesis, MC3T3-E1 osteoprogenitor cells were grown on poly(methyl methacrylate) (PMMA) fibers of 1.153 ± 0.310 μm diameter. The elastic modulus of the cell surface was measured by atomic force microscopy (AFM) with a colloidal probe. Overall cellular stiffness was found to increase more than three-fold in osteoprogenitors adhered to a fiber, as opposed to those grown on a flat substrate. Pharmacological inhibition of RhoA signalling activity decreased cellular stiffness and cytoskeletal integrity of osteoprogenitors growing on fibrous substrates. Finally, we demonstrated not only RhoA activity through its effector Rho-associated coiled coil kinase II (ROCKII), but also Myosin IIa promotes early osteogenic differentiation, as shown by alkaline phosphatase (ALP) staining. Previous studies have demonstrated the importance of ROCKII on early differentiation. Our results shed light on mechanisms underlying geometry sensing by highlighting the role of Myosin IIa in addition to ROCKII and could ultimately contribute to scaffold design strategies.",
author = "Tugba Ozdemir and Xu, {Li Chong} and Christopher Siedlecki and Brown, {Justin L.}",
year = "2013",
month = "1",
day = "1",
doi = "10.1039/c3ib40068a",
language = "English (US)",
volume = "5",
pages = "1407--1416",
journal = "Integrative Biology (United Kingdom)",
issn = "1757-9694",
publisher = "Royal Society of Chemistry",
number = "11",

}

Substrate curvature sensing through Myosin IIa upregulates early osteogenesis. / Ozdemir, Tugba; Xu, Li Chong; Siedlecki, Christopher; Brown, Justin L.

In: Integrative Biology (United Kingdom), Vol. 5, No. 11, 01.01.2013, p. 1407-1416.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Substrate curvature sensing through Myosin IIa upregulates early osteogenesis

AU - Ozdemir, Tugba

AU - Xu, Li Chong

AU - Siedlecki, Christopher

AU - Brown, Justin L.

PY - 2013/1/1

Y1 - 2013/1/1

N2 - Topographical cues mimicking the extracellular matrix (ECM) have demonstrated control over a diverse range of cellular behaviours including: initial adhesion, migration, cell growth, differentiation and death. How cells sense, and in turn translate, the topographical cues remains to be answered, but likely involves interactions through interfacial forces that influence cytoskeletal structure and integrin clustering, leading to the downstream activity of intracellular signalling cascades. Electrospun fibers have shown significant success as a biomimetic topography for bone tissue engineering applications, but mechanisms by which osteoprogenitor cells translate the fiber geometry into intracellular signalling activity is only recently being examined. We hypothesized that increased cellular differentiation observed on fibrous topography is due to acto-myosin contractility and cellular stiffness via the small GTPase RhoA. In order to evaluate this hypothesis, MC3T3-E1 osteoprogenitor cells were grown on poly(methyl methacrylate) (PMMA) fibers of 1.153 ± 0.310 μm diameter. The elastic modulus of the cell surface was measured by atomic force microscopy (AFM) with a colloidal probe. Overall cellular stiffness was found to increase more than three-fold in osteoprogenitors adhered to a fiber, as opposed to those grown on a flat substrate. Pharmacological inhibition of RhoA signalling activity decreased cellular stiffness and cytoskeletal integrity of osteoprogenitors growing on fibrous substrates. Finally, we demonstrated not only RhoA activity through its effector Rho-associated coiled coil kinase II (ROCKII), but also Myosin IIa promotes early osteogenic differentiation, as shown by alkaline phosphatase (ALP) staining. Previous studies have demonstrated the importance of ROCKII on early differentiation. Our results shed light on mechanisms underlying geometry sensing by highlighting the role of Myosin IIa in addition to ROCKII and could ultimately contribute to scaffold design strategies.

AB - Topographical cues mimicking the extracellular matrix (ECM) have demonstrated control over a diverse range of cellular behaviours including: initial adhesion, migration, cell growth, differentiation and death. How cells sense, and in turn translate, the topographical cues remains to be answered, but likely involves interactions through interfacial forces that influence cytoskeletal structure and integrin clustering, leading to the downstream activity of intracellular signalling cascades. Electrospun fibers have shown significant success as a biomimetic topography for bone tissue engineering applications, but mechanisms by which osteoprogenitor cells translate the fiber geometry into intracellular signalling activity is only recently being examined. We hypothesized that increased cellular differentiation observed on fibrous topography is due to acto-myosin contractility and cellular stiffness via the small GTPase RhoA. In order to evaluate this hypothesis, MC3T3-E1 osteoprogenitor cells were grown on poly(methyl methacrylate) (PMMA) fibers of 1.153 ± 0.310 μm diameter. The elastic modulus of the cell surface was measured by atomic force microscopy (AFM) with a colloidal probe. Overall cellular stiffness was found to increase more than three-fold in osteoprogenitors adhered to a fiber, as opposed to those grown on a flat substrate. Pharmacological inhibition of RhoA signalling activity decreased cellular stiffness and cytoskeletal integrity of osteoprogenitors growing on fibrous substrates. Finally, we demonstrated not only RhoA activity through its effector Rho-associated coiled coil kinase II (ROCKII), but also Myosin IIa promotes early osteogenic differentiation, as shown by alkaline phosphatase (ALP) staining. Previous studies have demonstrated the importance of ROCKII on early differentiation. Our results shed light on mechanisms underlying geometry sensing by highlighting the role of Myosin IIa in addition to ROCKII and could ultimately contribute to scaffold design strategies.

UR - http://www.scopus.com/inward/record.url?scp=84886422275&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84886422275&partnerID=8YFLogxK

U2 - 10.1039/c3ib40068a

DO - 10.1039/c3ib40068a

M3 - Article

C2 - 24104522

AN - SCOPUS:84886422275

VL - 5

SP - 1407

EP - 1416

JO - Integrative Biology (United Kingdom)

JF - Integrative Biology (United Kingdom)

SN - 1757-9694

IS - 11

ER -