ncaa team gear

Human Skin Aging Is Associated with Reduced Expression of the Stem Cell Markers beta1 Integrin and MCSP To ameliorate or inhibit these effects it is important to identify the principal factors that influence skin aging. Reduced stem cell abundance or self renewal ability is a feature of aging in a number of different tissues (Flores et al., 2005; Rando, 2006; Sharpless and DePinho, 2007; Rossi et al., 2008). Nevertheless, when we examined young and intrinsically aged murine skin (Giangreco et al., 2008), we found that despite alterations in epidermal proliferation, dermal thickness, and peripheral T cells, the abundance of CD34 positive epidermal stem cells did not decline with increasing age. Furthermore, young and aged murine epidermal stem cells have similar in vitro Seminoles 80 Rashad Greene White Stitched NCAA Jersey growth and differentiation potential (Stern and Bickenbach, 2007). These findings suggest that murine epidermal stem cells may be unaffected by intrinsic skin aging (Giangreco et al., 2008). We have now examined whether expression of epidermal stem cell markers changes during aging of human skin. We examined frozen sections of abdominal skin from 23 Caucasian donors (22 female and 1 male), three of whom were recently deceased. Tissue was obtained in compliance with the relevant European Union and United Kingdom regulations. Cadaveric skin samples were obtained with the approval of the Anatomy Department, University of Glasgow, UK. Other samples were obtained from Biopredic International, Rennes, France. Helsinki principles were adhered to and participants gave written, informed consent to provide samples for research. The ages of the donors were non uniformly distributed and instead clustered into three distinct groups, as shown in Figure 1a. The youngest age group ranged from 21 to 33 years (average age 30.5 years; n The intermediate group was aged 51 years (average 53.1 years; n The oldest group was over 60 years (average 68.5 years; n Immunostaining revealed a low level of epidermal p53 expression, indicating that the skin had not been subject to significant sun exposure (Tyrrell, 1996), except for two skin samples in the youngest age group (data not shown). Figure 1. Age related changes in epidermal structure. (a) Clustering of tissue donor age. (b) Assessment criteria for epidermal thickness (red), rete ridge (RR) height (blue), and basal cell density (purple cells). (c Representative hematoxylin and eosin stained skin sections from each age group. (f Quantification of epidermal thickness (f), RR height (g), and basal cell density (h) in all 21 to 33 (black), 51 to 59 (red), and over 60 year old samples (blue). There were no statistically significant differences in epidermal thickness between the different age groups (Figure 1f). However, both the 51 to 59 year old group and the over 60 year old group exhibited significantly reduced rete ridge height relative to the youngest group, as assessed by both unpaired t test (P and one way ANOVA post test trend analyses (P Figure 1g). There was also a statistically significant reduction in basal cell density when the oldest group was compared with the other two groups (P Figure 1h). Figure 2. Age related changes in proliferation and stem cell markers. (a Representative tissue sections from each age group stained for integrins (red) with 4 (DAPI) nuclear counterstain (green). (d) The level of anti integrin fluorescence at cell borders in the epidermal basal layer was measured essentially as described previously (Mol and Watt, 1997). Colored traces correspond to lines in micrograph. (e) integrin fluorescence (pixel intensity; arbitrary units (AU)) per basal layer cell border was determined in all samples. Each asterisk indicates significant difference in pixel intensity relative to other age groups. (f Representative tissue sections from each age group were stained with anti MCSP (red) with DAPI nuclear counterstain (green). (i) The number of MCSP positive basal cells was determined as a function of basement membrane length. (j Ki67 immunostaining (red) with DAPI nuclear counterstain (blue) of representative sections from each age group. (m) Number of Ki67 positive cells per 100 basement membrane. Full figure and legend (415K) Two markers of human interfollicular epidermal stem cells are melanoma chondroitin sulfate proteoglycan (MCSP; NG2; Legg et al., 2003) and high levels of integrins (Jones and Watt, 1993; Jones et al., 1995; Jensen et al., 1999). Frozen skin sections were labeled with anti integrin antibodies, and the fluorescence pixel intensity of lateral cell borders in the basal epidermal layer was quantified (Jones et al., 1995; Mol and Watt, 1997) (Figure 2a In the skin samples of 21 to 33 year old subjects, the cells with highest integrin levels tended to lie at the tops of the rete ridges (Figure 2a), as reported previously (Jones et al., 1995). Although the modal pixel intensity values for all age groups were similar, the mean and median values decreased with age (Figure 2e). In the 21 to 33 year old group, the mean was 143 arbitrary units and the median was 132. The 51 to 59 year old group had a mean of 139 and median of 120. In the over 60 year old group the mean was 103 and the median was 102. In addition, the lowest pixel intensity values were only found in the over 60 year old group (Figure 2e). A similar reduction in integrin expression has been observed in chronically UV exposed skin (Bosset et al., 2003). MCSP expression is confined to discrete clusters of cells, corresponding to the cells that express the highest integrin levels (Legg et al., 2003) (Figure 2f). There was no statistically significant difference in Ki67 abundance between Golden Bears Blank Gold Stitched NCAA Jersey the oldest samples and the other groups; however, there was a large spread in values within the over 60 year old samples (Figure 2m). We have previously reported that cells with the highest in vitro self renewal capacity express MCSP and high integrin levels (Jones and Watt, 1993; Jones et al., 1995; Legg et al., 2003). Our current findings are therefore consistent with the earlier report that significantly aged human epidermal cells exhibit reduced in vitro self renewal ability (Barrandon and Green, 1987). The reduction in integrin levels and MCSP expression with advancing age may also contribute to age associated changes in dermal thickness and skin vascularization. Integrins collaborate with growth factor receptors to influence growth Buckeyes 27 Eddie George Grey Stitched NCAA Jersey factor production and responsiveness (Legate et al., 2009; Streuli and Akhtar, 2009), and MCSP can enhance integrin dependent signaling (Yang et al., 2004). It will now be of interest to determine whether restoration of integrin levels might reverse some aspects of normal human skin aging. Overall, our studies provide evidence of previously unappreciated molecular changes that occur before the skin alterations most typically seen after 70 years of age (Makrantonaki and Zouboulis, 2007). Top of pageConflict of InterestGS is an employee of Chanel Parfums Beaut FW declares the receipt of a grant from Chanel. Top of pageReferencesTop of pageAcknowledgmentsWe are most grateful to Will Howat for excellent technical support. This work was supported by fellowships from the NIH (AG) and MRC (SJG), and funds from Chanel Parfums Beaut (FMW) and Cancer Research UK (AG, SJG, VF, FMW). We gratefully acknowledge the support of the University of Cambridge and Hutchison Whampoa. MORE ARTICLES LIKE THIS These links to content published by NPG are automatically generated. REVIEWSOPINION Epidermal homeostasis: do committed progenitors work while stem cells sleep?Nature Reviews Molecular Cell Biology Perspective (01 Jan 2008) See all 2 matches for Reviews RESEARCHIncreased In Vitro Lifespan of Primary Human Keratinocytes Correlates with Decreased MigrationJournal of Investigative Dermatology Letter Squamous cell cancers contain a side population of stem like cells that are made chemosensitive by ABC transporter blockadeBritish Journal of Cancer Original ArticleMarkers to Evaluate the Quality and Self Renewing Potential of Engineered Human Skin Substitutes In Vitro and after TransplantationJournal of Investigative Dermatology Original Article

ncaa team gear

Human skin wound dressings to treat cutaneous ulcers This news release is available in French. Quebec City, October 2, 2013 Researchers from Universit Laval s Faculty of Medicine and CHU de Qubec have shown that it is possible to treat venous ulcers unresponsive to conventional treatment with wound dressings made from human skin grown in vitro. A study published recently in the journal Advances in Skin and Wound Care demonstrates how this approach was successfully used to treat venous lower extremity ulcers in patients who had been chronically suffering from such wounds. About 1% of the population suffers from lower extremity ulcers. These wounds regularly become inflamed or infected and are very slow to heal, if they do at all. They are frequently associated with aging, diabetes, and circulatory system disorders such as varicose veins and oedema. "Obese individuals and those who work constantly standing up are especially vulnerable. These ulcers can persist for years. It can be a hellish clinical situation when standard treatments don t work," noted Dr. Franois A. Auger, director of both the study and LOEX, the tissue engineering and regenerative medicine laboratory where it was conducted. Standard treatment for ulcers involves methodically cleaning these wounds and applying compression bandages. Drugs became available around 20 years ago but they are expensive and their efficacy has been somewhat limited. A graft using the patient s own skin can be effective but is problematic because it requires a significant amount of skin to be removed from elsewhere on the body. This very problem inspired LOEX researchers to use their expertise with in vitro skin culture to create biomaterial free biological wound dressing. The process is complex and requires several steps: removing 1 cm2 of skin from the patient, isolating Longhorns 35 Kevin Durant White Stitched NCAA Jersey the appropriate cells, growing them in vitro, and creating a skin substitute with both dermis and epidermis. After eight weeks of growth the self assembled sheets of skin substitute can be applied over the ulcers, much like bandages, and replaced weekly as long as necessary. "This totally biological bandage is much more than a physical barrier," stresses Dr. Auger. "The cells secrete molecules that speed up healing by helping to set natural healing processes in motion. It would be hard to imagine a model closer to the human body s natural physiology." Tests were successfully carried out on five patients. It took only an average of seven weeks to cure 14 ulcers that had been affecting patients for at least six months, and in some cases, several years. "This is a last recourse once all other treatment options have been exhausted," notes Franois A. Auger. Dr. Auger sees another promising application for these biological shop ncaa sports bandages: "We have shown that this is effective for patients with leg ulcers. Now, we intend to carry out a clinical study to demonstrate that the same treatment works for patients with serious burns, as soon as we get the necessary approvals."In addition to Dr. Ospina, Nathalie Dub, Marie Hlne Rochon, Crimson Tide 10 AJ McCarron Red Limited Stitched NCAA Jersey Danielle Larouche, Vronique J. Moulin, and Lucie Germain.