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Estrogen depletion results in nanoscale morphology changes in dermal collagen.

Fang M, Liroff KG, Turner AS, Les CM, Orr BG, Holl MM - J. Invest. Dermatol. (2012)

Bottom Line: In addition, the overall width of the distribution, both values above and below the mean, was found to be increased.The change in width due to an increase in lower values of D-spacings was previously reported for ovine bone; however, this report demonstrates that the effect is also present in non-mineralized collagen fibrils.A nonparametric Kolmogorov-Smirnov test of the cumulative density function indicates a statistical difference in the sham and OVX D-spacing distributions (P<0.01).

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA.

ABSTRACT
Tissue cryo-sectioning combined with atomic force microscopy imaging reveals that the nanoscale morphology of dermal collagen fibrils, quantified using the metric of D-periodic spacing, changes under the condition of estrogen depletion. Specifically, a new subpopulation of fibrils with D-spacings in the region between 56 and 59 nm is present 2 years following ovariectomy in ovine dermal samples. In addition, the overall width of the distribution, both values above and below the mean, was found to be increased. The change in width due to an increase in lower values of D-spacings was previously reported for ovine bone; however, this report demonstrates that the effect is also present in non-mineralized collagen fibrils. A nonparametric Kolmogorov-Smirnov test of the cumulative density function indicates a statistical difference in the sham and OVX D-spacing distributions (P<0.01).

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Related in: MedlinePlus

AFM deflection images of dermis contain domains of collagen fibril bundles. Panel a and b are representative images from a sham dermis sample; panel c and d are images from an OVX dermis sample. Panel a captures potentially two fibril bundles (the rough area at the bottom of the scan is coursed by microtome sectioning). Panel b shows one fibril bundle on top of another (The boundary is marked by the white dashed line), notice that a few fibrils that are underneath one bundle are on the surface of another bundle.Panel c is the region marked by the black box in panel b. Panel e and f capture the only region with collagen fibrils found in the 50 micron area of OVX dermis (panel d).
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Figure 1: AFM deflection images of dermis contain domains of collagen fibril bundles. Panel a and b are representative images from a sham dermis sample; panel c and d are images from an OVX dermis sample. Panel a captures potentially two fibril bundles (the rough area at the bottom of the scan is coursed by microtome sectioning). Panel b shows one fibril bundle on top of another (The boundary is marked by the white dashed line), notice that a few fibrils that are underneath one bundle are on the surface of another bundle.Panel c is the region marked by the black box in panel b. Panel e and f capture the only region with collagen fibrils found in the 50 micron area of OVX dermis (panel d).

Mentions: The combination of cryostat sectioning and AFM imaging has been recently highlighted by Graham et al. as an advantageous tool for morphological studies of collagen matrix protein structures in soft tissues.(Graham et al., 2010) Although histological data reveal the orientation and organization of collagen fibril bundles in dermis, the resolution is limited in resolving fibril organizations within a bundle. AFM imaging can overcome this issue and representative images of fibril bundles from ovine dermis are illustrated in Figure 1. Qualitatively, on the 50 micron scale and above, the fibril bundles were randomly oriented in a wavy pattern; within a fibril bundle, on the order of 10 micron scale, collagen fibrils were bundled in a parallel longitudinal direction and individual fibrils crossing the bundle domains were frequently observed (see the arrow heads in figure 1b and 1e). The function of these crossing fibrils is unclear.


Estrogen depletion results in nanoscale morphology changes in dermal collagen.

Fang M, Liroff KG, Turner AS, Les CM, Orr BG, Holl MM - J. Invest. Dermatol. (2012)

AFM deflection images of dermis contain domains of collagen fibril bundles. Panel a and b are representative images from a sham dermis sample; panel c and d are images from an OVX dermis sample. Panel a captures potentially two fibril bundles (the rough area at the bottom of the scan is coursed by microtome sectioning). Panel b shows one fibril bundle on top of another (The boundary is marked by the white dashed line), notice that a few fibrils that are underneath one bundle are on the surface of another bundle.Panel c is the region marked by the black box in panel b. Panel e and f capture the only region with collagen fibrils found in the 50 micron area of OVX dermis (panel d).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3375339&req=5

Figure 1: AFM deflection images of dermis contain domains of collagen fibril bundles. Panel a and b are representative images from a sham dermis sample; panel c and d are images from an OVX dermis sample. Panel a captures potentially two fibril bundles (the rough area at the bottom of the scan is coursed by microtome sectioning). Panel b shows one fibril bundle on top of another (The boundary is marked by the white dashed line), notice that a few fibrils that are underneath one bundle are on the surface of another bundle.Panel c is the region marked by the black box in panel b. Panel e and f capture the only region with collagen fibrils found in the 50 micron area of OVX dermis (panel d).
Mentions: The combination of cryostat sectioning and AFM imaging has been recently highlighted by Graham et al. as an advantageous tool for morphological studies of collagen matrix protein structures in soft tissues.(Graham et al., 2010) Although histological data reveal the orientation and organization of collagen fibril bundles in dermis, the resolution is limited in resolving fibril organizations within a bundle. AFM imaging can overcome this issue and representative images of fibril bundles from ovine dermis are illustrated in Figure 1. Qualitatively, on the 50 micron scale and above, the fibril bundles were randomly oriented in a wavy pattern; within a fibril bundle, on the order of 10 micron scale, collagen fibrils were bundled in a parallel longitudinal direction and individual fibrils crossing the bundle domains were frequently observed (see the arrow heads in figure 1b and 1e). The function of these crossing fibrils is unclear.

Bottom Line: In addition, the overall width of the distribution, both values above and below the mean, was found to be increased.The change in width due to an increase in lower values of D-spacings was previously reported for ovine bone; however, this report demonstrates that the effect is also present in non-mineralized collagen fibrils.A nonparametric Kolmogorov-Smirnov test of the cumulative density function indicates a statistical difference in the sham and OVX D-spacing distributions (P<0.01).

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA.

ABSTRACT
Tissue cryo-sectioning combined with atomic force microscopy imaging reveals that the nanoscale morphology of dermal collagen fibrils, quantified using the metric of D-periodic spacing, changes under the condition of estrogen depletion. Specifically, a new subpopulation of fibrils with D-spacings in the region between 56 and 59 nm is present 2 years following ovariectomy in ovine dermal samples. In addition, the overall width of the distribution, both values above and below the mean, was found to be increased. The change in width due to an increase in lower values of D-spacings was previously reported for ovine bone; however, this report demonstrates that the effect is also present in non-mineralized collagen fibrils. A nonparametric Kolmogorov-Smirnov test of the cumulative density function indicates a statistical difference in the sham and OVX D-spacing distributions (P<0.01).

Show MeSH
Related in: MedlinePlus