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Epidermal stem cells are retained in vivo throughout skin aging.

Giangreco A, Qin M, Pintar JE, Watt FM - Aging Cell (2008)

Bottom Line: In healthy individuals, skin integrity is maintained by epidermal stem cells which self-renew and generate daughter cells that undergo terminal differentiation.It is currently unknown whether epidermal stem cells influence or are affected by skin aging.We therefore compared young and aged skin stem cell abundance, organization, and proliferation.

View Article: PubMed Central - PubMed

Affiliation: Cancer Research UK, Cambridge Research Institute, Li Ka Shing Centre, Robinson Way, Cambridge CB2 0RE, UK. adam.giangreco@cancer.org.uk

ABSTRACT
In healthy individuals, skin integrity is maintained by epidermal stem cells which self-renew and generate daughter cells that undergo terminal differentiation. It is currently unknown whether epidermal stem cells influence or are affected by skin aging. We therefore compared young and aged skin stem cell abundance, organization, and proliferation. We discovered that despite age-associated differences in epidermal proliferation, dermal thickness, follicle patterning, and immune cell abundance, epidermal stem cells were maintained at normal levels throughout life. These findings, coupled with observed dermal gene expression changes, suggest that epidermal stem cells themselves are intrinsically aging resistant and that local environmental or systemic factors modulate skin aging.

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Related in: MedlinePlus

Skin aging results in changes in Igfbp3 transcript abundance. (A) Bioinformatic analysis of relative Igf/Igfbp signalling pathway gene abundance in matrix (green), outer root sheath (ORS, black), dermal fibroblast (DF, red), dermal papilla (DP, yellow), or melanocyte (blue) cell populations relative to ORS/basal keratinocytes. Most Igf pathway members were enriched within dermal compartments (DF and DP). (B) Quantitative polymerase chain reaction of whole-skin cDNA to determine Igf/Igfbp expression in 2-month-old, 6-month-old, 18-month-old, and 22-month-old mice. (n = 3 mice/age; *P < 0.05).
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fig05: Skin aging results in changes in Igfbp3 transcript abundance. (A) Bioinformatic analysis of relative Igf/Igfbp signalling pathway gene abundance in matrix (green), outer root sheath (ORS, black), dermal fibroblast (DF, red), dermal papilla (DP, yellow), or melanocyte (blue) cell populations relative to ORS/basal keratinocytes. Most Igf pathway members were enriched within dermal compartments (DF and DP). (B) Quantitative polymerase chain reaction of whole-skin cDNA to determine Igf/Igfbp expression in 2-month-old, 6-month-old, 18-month-old, and 22-month-old mice. (n = 3 mice/age; *P < 0.05).

Mentions: Based on our observation that skin aging did not correlate with a reduction in the number of epidermal stem cells, we hypothesized that aging might instead be regulated by environmental components. The Igf signalling pathway has previously been identified as a key mediator of both epidermal proliferation (Edmondson et al., 2003) and skin peripheral immunity (Sharp et al., 2005a). In addition, Igf/Igfbp signalling is a well-established component of many aging models, where it influences tissue growth, glycolysis, adiposity, and cellular stress resistance (Kenyon, 2001; Holzenberger et al., 2003; Tatar et al., 2003). Therefore, using existing but previously uncharacterized microarray data (Rendl et al., 2005), we compared Igf/Igfbp family member expression within skin dermal fibroblasts (DFs) and dermal papilla (DP) relative to melanocyte, matrix, and outer root sheath (ORS) cells. Most Igf pathway members were strongly (200–1500%) up-regulated in DF/DP cells compared to other cell types, suggesting that skin Igf signalling is primarily dermis derived (Fig. 5A).


Epidermal stem cells are retained in vivo throughout skin aging.

Giangreco A, Qin M, Pintar JE, Watt FM - Aging Cell (2008)

Skin aging results in changes in Igfbp3 transcript abundance. (A) Bioinformatic analysis of relative Igf/Igfbp signalling pathway gene abundance in matrix (green), outer root sheath (ORS, black), dermal fibroblast (DF, red), dermal papilla (DP, yellow), or melanocyte (blue) cell populations relative to ORS/basal keratinocytes. Most Igf pathway members were enriched within dermal compartments (DF and DP). (B) Quantitative polymerase chain reaction of whole-skin cDNA to determine Igf/Igfbp expression in 2-month-old, 6-month-old, 18-month-old, and 22-month-old mice. (n = 3 mice/age; *P < 0.05).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2339763&req=5

fig05: Skin aging results in changes in Igfbp3 transcript abundance. (A) Bioinformatic analysis of relative Igf/Igfbp signalling pathway gene abundance in matrix (green), outer root sheath (ORS, black), dermal fibroblast (DF, red), dermal papilla (DP, yellow), or melanocyte (blue) cell populations relative to ORS/basal keratinocytes. Most Igf pathway members were enriched within dermal compartments (DF and DP). (B) Quantitative polymerase chain reaction of whole-skin cDNA to determine Igf/Igfbp expression in 2-month-old, 6-month-old, 18-month-old, and 22-month-old mice. (n = 3 mice/age; *P < 0.05).
Mentions: Based on our observation that skin aging did not correlate with a reduction in the number of epidermal stem cells, we hypothesized that aging might instead be regulated by environmental components. The Igf signalling pathway has previously been identified as a key mediator of both epidermal proliferation (Edmondson et al., 2003) and skin peripheral immunity (Sharp et al., 2005a). In addition, Igf/Igfbp signalling is a well-established component of many aging models, where it influences tissue growth, glycolysis, adiposity, and cellular stress resistance (Kenyon, 2001; Holzenberger et al., 2003; Tatar et al., 2003). Therefore, using existing but previously uncharacterized microarray data (Rendl et al., 2005), we compared Igf/Igfbp family member expression within skin dermal fibroblasts (DFs) and dermal papilla (DP) relative to melanocyte, matrix, and outer root sheath (ORS) cells. Most Igf pathway members were strongly (200–1500%) up-regulated in DF/DP cells compared to other cell types, suggesting that skin Igf signalling is primarily dermis derived (Fig. 5A).

Bottom Line: In healthy individuals, skin integrity is maintained by epidermal stem cells which self-renew and generate daughter cells that undergo terminal differentiation.It is currently unknown whether epidermal stem cells influence or are affected by skin aging.We therefore compared young and aged skin stem cell abundance, organization, and proliferation.

View Article: PubMed Central - PubMed

Affiliation: Cancer Research UK, Cambridge Research Institute, Li Ka Shing Centre, Robinson Way, Cambridge CB2 0RE, UK. adam.giangreco@cancer.org.uk

ABSTRACT
In healthy individuals, skin integrity is maintained by epidermal stem cells which self-renew and generate daughter cells that undergo terminal differentiation. It is currently unknown whether epidermal stem cells influence or are affected by skin aging. We therefore compared young and aged skin stem cell abundance, organization, and proliferation. We discovered that despite age-associated differences in epidermal proliferation, dermal thickness, follicle patterning, and immune cell abundance, epidermal stem cells were maintained at normal levels throughout life. These findings, coupled with observed dermal gene expression changes, suggest that epidermal stem cells themselves are intrinsically aging resistant and that local environmental or systemic factors modulate skin aging.

Show MeSH
Related in: MedlinePlus