Skin aging: the main culprit is grabbed by the hand
A molecule regulating skin aging has been identified
NanoNewsNet based on INSERM: The skin aging regulatorWith age, the skin irreversibly loses its properties and, despite the progress in regenerative medicine, scientists can not yet oppose this process.
A group of scientists from the National Institute of Health and Medical Research (Institut National de la Sante et de la Recherche Medicale – INSERM), France, made a major contribution to its study by identifying cellular and molecular mechanisms involved in the preservation of skin cells and in the healing of the epidermis in old age. These mechanisms involve the CD98hc transporter protein, which is involved in the renewal of the epidermis and is an indicator of the skin's ability to regenerate.
The epidermis – the surface layer of the skin – consists mainly of keratinocytes, which are continuously updated in humans during a 21-day cycle. These cells are located on a membrane consisting of extracellular (extracellular) matrix components that connect the epidermis to the dermis – a deep layer of skin. The epidermis is renewed due to the proliferation and differentiation of cells, which together maintain the balance of mature tissues. This balance is of great importance for the proper functioning of tissues, and any disturbances in it are responsible for the physical changes associated with aging: sagging of the skin due to a decrease in the proliferation of its cells, deterioration of wound healing, hair loss, etc.
Skin renewal is supported by stem keratinocytes,
having the ability to divide and differentiate.
When dividing , they form two identical daughter cells,
one of which remains in place and is subsequently divided again,
and the second migrates to the upper layer,
gradually becoming more differentiated.
French researchers have studied numerous cellular factors involved in maintaining this balance. They paid special attention to CD98hc, a protein known to interact with receptors that cause skin aging. Scientists know that with age, the activity of the CD98hc transporter and integrins (receptors associated with extracellular matrix components) is disrupted. However, until now, the molecular mechanisms involved remained unknown.
Experiments conducted on mice have shown that the removal of the CD98hc gene (encoding the CD98hc transporter protein) disrupts the balance of the skin and its healing process. In addition, by altering cell proliferation and migration, the deletion of this gene causes a malfunction in the hair follicle cycle. Scientists have deciphered the whole complex of complex mechanisms associated with CD98hc, in particular, the deregulation of the integrin function caused by the absence of this molecule. Their data confirm what has been described in vitro: the CD98hc amino acid transporter modulates the integrin signal, which is very important for skin renewal. Thus, CD98hc is actively involved in skin renewal by effectively replenishing cells when necessary (for example, during wound healing).
"Apparently, the CD98hc molecule is necessary for rapid and effective skin renewal. The decrease in its expression observed in vivo in old mice confirms its role in tissue preservation, hair follicle cycle and skin healing, which are disrupted with age," says study leader Chloe Feral. "The status of the CD98hc carrier in vivo may be an indicator of the skin's ability to self-renew."
The article Boulter et al. CD98hc (SLC3A2) regulation of skin homeostasis wanes with age is published in The Journal of Cell Biology.
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