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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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D-Periodic Gap/Overlap spacings from individual sham (n = 5, panel a) and OVX (n = 5, panel b) ovine dermis. The box-plot shows the interquartile (middle 50% of data), the horizontal line inside the box is the mean, the diamond is the median, and the whiskers provided the minimum and maximum observation. The numbers in parentheses are numbers of fibrils measured in each specimen. Two tailed student T-tests between Sham and OVX group suggests no differences between the means (p = 0.249).
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Figure 2: D-Periodic Gap/Overlap spacings from individual sham (n = 5, panel a) and OVX (n = 5, panel b) ovine dermis. The box-plot shows the interquartile (middle 50% of data), the horizontal line inside the box is the mean, the diamond is the median, and the whiskers provided the minimum and maximum observation. The numbers in parentheses are numbers of fibrils measured in each specimen. Two tailed student T-tests between Sham and OVX group suggests no differences between the means (p = 0.249).

Mentions: Quantitatively, the characteristic collagen fibril D-spacing was measured and employed as the main morphological metric. For each biopsy, at least 60 fibrils from a minimum of four and an average of five randomly selected 50 μm locations were analyzed. The difference in the number of fibrils obtained for each biopsy is due to variation in collagen abundance at the location of AFM tip engagement. Measurements from each skin biopsy were pooled together to yield the average D-spacing (Figure 2). The mean values for five sham ovine were 62.0, 61.6, 62.7, 63.1, and 62.6 nm. The mean values for the OVX ovine were 61.8, 61.3, 60.7 and 62.5 nm. The means from sham and OVX are not significantly different (p =0.249) when compared with the two tailed student T-test.


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)

D-Periodic Gap/Overlap spacings from individual sham (n = 5, panel a) and OVX (n = 5, panel b) ovine dermis. The box-plot shows the interquartile (middle 50% of data), the horizontal line inside the box is the mean, the diamond is the median, and the whiskers provided the minimum and maximum observation. The numbers in parentheses are numbers of fibrils measured in each specimen. Two tailed student T-tests between Sham and OVX group suggests no differences between the means (p = 0.249).
© Copyright Policy
Related In: Results  -  Collection

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

Figure 2: D-Periodic Gap/Overlap spacings from individual sham (n = 5, panel a) and OVX (n = 5, panel b) ovine dermis. The box-plot shows the interquartile (middle 50% of data), the horizontal line inside the box is the mean, the diamond is the median, and the whiskers provided the minimum and maximum observation. The numbers in parentheses are numbers of fibrils measured in each specimen. Two tailed student T-tests between Sham and OVX group suggests no differences between the means (p = 0.249).
Mentions: Quantitatively, the characteristic collagen fibril D-spacing was measured and employed as the main morphological metric. For each biopsy, at least 60 fibrils from a minimum of four and an average of five randomly selected 50 μm locations were analyzed. The difference in the number of fibrils obtained for each biopsy is due to variation in collagen abundance at the location of AFM tip engagement. Measurements from each skin biopsy were pooled together to yield the average D-spacing (Figure 2). The mean values for five sham ovine were 62.0, 61.6, 62.7, 63.1, and 62.6 nm. The mean values for the OVX ovine were 61.8, 61.3, 60.7 and 62.5 nm. The means from sham and OVX are not significantly different (p =0.249) when compared with the two tailed student T-test.

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