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Osteocyte shape and mechanical loading.

van Oers RF, Wang H, Bacabac RG - Curr Osteoporos Rep (2015)

Bottom Line: In vitro, round osteocytes are more mechanosensitive than flat osteocytes.Altered lacunar morphology has been associated with bone pathology.It is important to know whether osteocyte shape is part of the etiology.

View Article: PubMed Central - PubMed

Affiliation: Department of Oral Cell Biology, ACTA - University of Amsterdam and VU University Amsterdam, MOVE Research Institute Amsterdam, Gustav Mahlerlaan 3004, 1081 LA, Amsterdam, The Netherlands, rfmvoers@gmail.com.

ABSTRACT
There is considerable variation in the shape of osteocyte lacunae, which is likely to influence the function of osteocytes as the professional mechanosensors of bone. In this review, we first discussed how mechanical loading could affect the shape of osteocyte lacunae. Recent studies show that osteocyte lacunae are aligned to collagen. Since collagen fiber orientation is affected by loading mode, this alignment may help to understand how mechanical loading shapes the osteocyte lacuna. Secondly, we discussed how the shape of osteocytes could influence their mechanosensation. In vitro, round osteocytes are more mechanosensitive than flat osteocytes. Altered lacunar morphology has been associated with bone pathology. It is important to know whether osteocyte shape is part of the etiology.

No MeSH data available.


Related in: MedlinePlus

Hypothetical explanation of observed differences in preferential collagen fiber orientation with loading mode (tension or compression)
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Fig2: Hypothetical explanation of observed differences in preferential collagen fiber orientation with loading mode (tension or compression)

Mentions: How could the dominant loading mode, tension or compression, produce bone with longitudinal or transverse collagen? Osteons align to the dominant loading, whether that is tension or compression [36]. We previously proposed a mechanobiological explanation for this alignment [37–40]: strain concentrations at the lateral sides of the osteonal tunnel induce osteocyte signals to repel the digging osteoclasts, orienting them in the loading direction. This mechanism does not discriminate between tension and compression: osteoclasts would avoid both compressed and tensed bone. Though both compression and tension guide the osteonal tunnel in the longitudinal direction [36], they differ in the orientation of stretch (positive strain) on the tunnel wall: cavities in bone under compression dilate transversely, while cavities under tension are stretched longitudinally (Fig. 2). The orientation of stretch in the osteoid layer thus coincides with the preferential orientation of collagen in the finished osteon. Osteocyte shape, in turn, might also reflect the stretch in the osteoid layer of its formation.Fig. 2


Osteocyte shape and mechanical loading.

van Oers RF, Wang H, Bacabac RG - Curr Osteoporos Rep (2015)

Hypothetical explanation of observed differences in preferential collagen fiber orientation with loading mode (tension or compression)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4352610&req=5

Fig2: Hypothetical explanation of observed differences in preferential collagen fiber orientation with loading mode (tension or compression)
Mentions: How could the dominant loading mode, tension or compression, produce bone with longitudinal or transverse collagen? Osteons align to the dominant loading, whether that is tension or compression [36]. We previously proposed a mechanobiological explanation for this alignment [37–40]: strain concentrations at the lateral sides of the osteonal tunnel induce osteocyte signals to repel the digging osteoclasts, orienting them in the loading direction. This mechanism does not discriminate between tension and compression: osteoclasts would avoid both compressed and tensed bone. Though both compression and tension guide the osteonal tunnel in the longitudinal direction [36], they differ in the orientation of stretch (positive strain) on the tunnel wall: cavities in bone under compression dilate transversely, while cavities under tension are stretched longitudinally (Fig. 2). The orientation of stretch in the osteoid layer thus coincides with the preferential orientation of collagen in the finished osteon. Osteocyte shape, in turn, might also reflect the stretch in the osteoid layer of its formation.Fig. 2

Bottom Line: In vitro, round osteocytes are more mechanosensitive than flat osteocytes.Altered lacunar morphology has been associated with bone pathology.It is important to know whether osteocyte shape is part of the etiology.

View Article: PubMed Central - PubMed

Affiliation: Department of Oral Cell Biology, ACTA - University of Amsterdam and VU University Amsterdam, MOVE Research Institute Amsterdam, Gustav Mahlerlaan 3004, 1081 LA, Amsterdam, The Netherlands, rfmvoers@gmail.com.

ABSTRACT
There is considerable variation in the shape of osteocyte lacunae, which is likely to influence the function of osteocytes as the professional mechanosensors of bone. In this review, we first discussed how mechanical loading could affect the shape of osteocyte lacunae. Recent studies show that osteocyte lacunae are aligned to collagen. Since collagen fiber orientation is affected by loading mode, this alignment may help to understand how mechanical loading shapes the osteocyte lacuna. Secondly, we discussed how the shape of osteocytes could influence their mechanosensation. In vitro, round osteocytes are more mechanosensitive than flat osteocytes. Altered lacunar morphology has been associated with bone pathology. It is important to know whether osteocyte shape is part of the etiology.

No MeSH data available.


Related in: MedlinePlus