Characterization of a New Reconstructed Full Thickness Skin Model, T-Skin™, and its Application for Investigations of Anti-Aging Compounds.

BACKGROUND: We have characterized a new reconstructed full-thickness skin model, T-Skin™, compared to normal human skin (NHS) and evaluated its use in testing anti-aging compounds. METHODS: The structure and layer-specific markers were compared with NHS using histological and immunohistological staining. In anti-aging experiments, T-SkinTM was exposed to retinol (10 µM) or vitamin C (200 µM) for 5 days, followed by immunohistological staining evaluation. RESULTS: T-Skin™ exhibits a well stratified, differentiated and self-renewing epidermis with a dermal compartment of functional fibroblasts. Epidermal (cytokeratin 10, transglutaminase 1), dermo-epidermal junction (DEJ) (laminin 5, collagen-IV, collagen VII) and dermally-located (fibrillin 1, procollagen I) biomarkers were similar to those in NHS. Treatment of T-Skin™ with retinol decreased the expression of differentiation markers, cytokeratin 10 and transglutaminase 1 and increased the proliferation marker, Ki67, in epidermis basal-layer cells. Vitamin C increased the expression of DEJ components, collagen IV and VII and dermal procollagen 1. CONCLUSIONS: T-Skin™ exhibits structural and biomarker location characteristics similar to NHS. Responses of T-Skin™ to retinol and vitamin C treatment were consistent with those of their known anti-aging effects. T-Skin™ is a promising model to investigate responses of epidermal, DEJ and dermal regions to new skin anti-ageing compounds.

Pharmacologic study of C-terminal fragments of frog skin calcitonin gene-related peptide.

The calcitonin gene-related peptide from the skin of the frog Phyllomedusa bicolor (pbCGRP) is a 37-residue neuropeptide that differs from human alpha CGRP (halphaCGRP) at 16 positions. The affinities of the C-terminal fragments of pbCGRP and halphaCGRP were evaluated in SK-N-MC cells: pbCGRP(8-37) (K(i)=0.2nM) and pbCGRP(27-37) (K(i)=95nM) were, respectively, 3 times and 20 times more potent than the human fragments halphaCGRP(8-37) and halphaCGRP(27-37). Their antagonistic potencies were measured in SK-N-MC and Col 29 cells, and the rat vas deferens. pbCGRP(8-37) inhibited the halphaCGRP-stimulated production of cAMP by SK-N-MC and Col 29 cells 3 to 4 times more strongly than halphaCGRP(8-37). Thus pbCGRP(8-37) is the most potent CGRP-1 competitive antagonist of all the natural sequences reported to date. pbCGRP(27-37) was also as potent as [D(31), A(34), F(35)] halphaCGRP(27-37), a prototypic antagonist analog derived from structure-activity relationship studies of halphaCGRP(8-37).

Effect of age and anatomical site on density of sensory innervation in human epidermis.

BACKGROUND: Aging leads to decline of multiple cutaneous physiological functions including decreased sweating, immune responsiveness, thermoregulation, DNA repair, and sensory and tactile perception. Interestingly, sensory perception, like that for pain or spatial acuity, varies in different body parts. OBJECTIVE: To evaluate epidermal innervation according to age and anatomical site. METHODS: Eighty-two biopsy samples from surgical procedures involving 82 patients of different ages (20-93 years) were analyzed. Four anatomical sites were examined: 2 from facial areas (upper eyelid and preauricular area) and 2 from truncal areas (abdomen and mammary area). Epidermal innervation was detected using a marker of neural cells, the protein gene product 9.5. The basement membrane was stained with type IV collagen antibodies. The epidermal area occupied by nerve endings was then calculated using image analysis. RESULTS: A trend displaying age-associated decreased epidermal innervation of facial skin was found. Epidermal innervation of abdominal skin did not change with age, and an age-associated increased innervation was observed in mammary skin. Also, the number of epidermal nerves in facial areas tested (palpebral and preauricular areas) was significantly higher than their number in the abdomen and mammary area. Eyelid epidermis showed the highest ratio of nerve fiber surface to epidermal surface. CONCLUSIONS: Epidermal nerve density variations could explain the different sensitivity threshold in different parts of the body. Decreased spatial discrimination with aging may be associated with decreased epidermal nerve density.