- Age-related changes are due to many factors influencing the structure of the epidermis (texture changes) as well as changes in the dermis (loss of volume).
- The following study shows the role of hyaluronic acid (HA), BOTH large and small fragments in Epidermal age related skin changes.
- This study shows that topical application of small HA fragments (bovine derived) in aged mice skin:
- by enabling the keratinocytes (epidermis) to proliferate and increases skin thickness
- they do NOT enable keratinocyte differrentiation or barrier repair
- Exactly the opposite, large HA fragments:
- enable keratinocytes to differentiate and to have a functional barrier function
- minimally promote keratinocyte proliferation and skin thickness
- Both large and small HA fragments are ineffective :
- in CD44 knockout mice. This suggests the important signaling role CD44 appears to play.
- when RHO kinase activity is blocked (with Y27632 or protein kinase activity with Ro31-8220)
Conclusion: This study could show (not in humans) that not only hyaluronic acid plays a role in the dermis (as a filler), but also in the maintenance of the epidermis.
The full article is available by clicking HERE.
Bibliography: Hyaluronan-CD44 interaction promotes c-Jun signaling and miRNA21 expression leading to Bcl-2 expression and chemoresistance in breast cancer cells. Chen L, Bourguignon LY. Mol Cancer. 2014 Mar 8;13:52.
Source of information: here