A secretion of the mollusc Cryptomphalus aspersa promotes proliferation, migration and survival of keratinocytes and dermal fibroblasts in vitro.
ABSTRACT Regenerative properties of skin decrease with age, and thus, the search for substances that minimize cutaneous ageing has increased in the last few years. The secretion of the mollusc Cryptomphalus Aspersa (SCA) is a natural product that bears regenerative properties when applied topically. The purpose of this work is to study the in vitro effects of SCA on cell proliferation and migration, as well as on cell-cell (E-cadherin and β-catenin) and cell-substrate (vinculin and β1-integrin) adhesion proteins expression, using a human keratinocyte cell line (HaCaT cells) and primary dermal fibroblasts (HF). We tested the effects of SCA on cell proliferation using a colorimetric assay. In addition, SCA-induced changes on cell migration were studied by wound-healing assays. Besides, Western blot and immunofluorescence microscopy were carried out to test the expression of different cell adhesion proteins. We found that SCA promotes proliferation and migration of HaCaT cells in a time- and dose-dependent manner. Moreover, treatment with SCA increases the migratory behaviour and the expression of adhesion molecules in both HaCaT and HF. Finally, SCA also improves cell survival and promotes phosphorylation of FAK and nuclear localization of β-catenin. These results shed light on the molecular mechanisms underlying the regenerative properties of SCA, based on its promoting effect on skin cell migration, proliferation and survival. Moreover, these results support future clinical uses of SCA in the regeneration of wounded tissues.
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ABSTRACT: Inadequate or inappropriate adhesion of epithelial cells to extracellular matrix leads to a form of apoptosis known as anoikis. During various tissue remodelling events, such as wound healing or carcinoma invasion, changes in the physical properties, and/or composition of the extracellular matrix, can lead to anoikis of epithelial cells that lack appropriate receptor-matrix interactions. Laminin-5 is the major ligand for keratinocyte adhesion in the epidermis, and it also promotes keratinocyte survival in vivo and in vitro. Integrins alpha 3 beta 1 and alpha 6 beta 4 are the major receptors for laminin-5; however, specific roles for these integrins in keratinocyte survival have not been determined. In the current study, we exploited keratinocyte cell lines derived from wild-type or alpha 3 integrin knockout mice to reveal a critical role for alpha 3 beta 1 in protecting keratinocytes from apoptosis upon serum withdrawal. We show that alpha 3 beta 1-mediated adhesion to laminin-5 extracellular matrix inhibits proteolytic activation of caspase-3 and TUNEL-staining, both hallmarks of apoptosis. We also show that alpha 3 beta1-mediated adhesion activates focal adhesion kinase (FAK) and extracellular signal-regulated kinase (ERK), and that inhibition of either FAK or ERK signaling leads to apoptosis of keratinocytes attached to laminin-5. alpha 6 beta 4-mediated adhesion to laminin-5 only partially protects cells from apoptosis in the absence of alpha 3 beta 1, and alpha 6 beta 4 is not necessary for cell survival in the presence of alpha 3 beta 1. These results suggest that alpha 3 beta 1 is necessary and sufficient for maximal keratinocyte survival on laminin-5. We propose a model to address the potential importance of alpha 3 beta 1-mediated survival for migrating keratinocytes at the leading edge of a cutaneous wound.Journal of Cell Science 09/2004; 117(Pt 18):4043-54. · 5.88 Impact Factor
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ABSTRACT: Aging of skin is an intricate biological process consisting of two types. While intrinsic or chronological aging is an inevitable process, photoaging involves the premature aging of skin occurring due to cumulative exposure to ultraviolet radiation. Chronological and photoaging both have clinically differentiable manifestations. Various natural and synthetic retinoids have been explored for the treatment of aging and many of them have shown histological and clinical improvement, but most of the studies have been carried out in patients presenting with photoaged skin. Amongst the retinoids, tretinoin possibly is the most potent and certainly the most widely investigated retinoid for photoaging therapy. Although retinoids show promise in the treatment of skin aging, irritant reactions such as burning, scaling or dermatitis associated with retinoid therapy limit their acceptance by patients. This problem is more prominent with tretinoin and tazarotene whereas other retinoids mainly represented by retinaldehyde and retinol are considerably less irritating. In order to minimize these side effects, various novel drug delivery systems have been developed. In particular, nanoparticles have shown a good potential in improving the stability, tolerability and efficacy ofretinoids like tretinoin and retinol. However, more elaborate clinical studies are required to confirm their advantage in the delivery of topical retinoids.Clinical Interventions in Aging 02/2006; 1(4):327-48. · 2.65 Impact Factor
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ABSTRACT: Chronic exposure to solar ultraviolet irradiation can result in wrinkle formation in many individuals. Wrinkling appears to be the conclusion of mechanisms that result in decreased synthesis of extracellular matrix molecules within the dermis, accompanied by increased remodeling of the matrix by specific endopeptidases (matrix metalloproteinases) and proteases (originating from infiltrating cells of the immune system). In this review, we discuss the changes that occur in the extracellular matrix of photoaged skin and the mechanisms by which they are modulated.Journal of Cosmetic Dermatology 01/2006; 4(4):230-6. · 0.87 Impact Factor