Maintaining elasticity: Kao study determines the effect ageing and UV exposure has on crucial protein linked to elastin
This study is the continuation of the Japanese personal care company’s 30 years of research into skin ageing, skin wrinkles and the role of dermal elastin.
Most notably in 2011, Kao claimed that it was the first to report that microfibrillar-associated protein 4 (MFAP-4) was essential for the formation of elastin.
According to Kao, MFAP-4 assists with fibrillin assembly and forms microfibrils, which bind with elastin molecules to form mature elastin.
Its findings determined that high levels of MFAP-4 enhanced the formation of elastin while a reduction of MFAP-4 inhibited elastin development.
Elastin is a protein complex consisting mainly of elastin molecules in a ‘stacked formation’. It has a highly rubber-like construction and plays an important role in maintaining skin elasticity, keeping skin firm and smooth.
As skin loses its elasticity, also known as elastosis, it begins to sag and leads to the formation of fine lines and wrinkles.
Elastin formation is crucial for maintaining skin elasticity, but it is known to decrease and degenerate due to ageing and UV exposure.
MFAP-4 relationship with skin elasticity
For this study, Kao researchers investigated further into the relationship between MFAP-4 expression and skin elasticity.
Furthermore, the team also quantitatively examined the effects of ageing and UV exposure on MFAP-4.
The team measured the MFAP-4 gene expression of women in their 20s and 30s to compare it with the MFAP-4 levels of women in their 60s.
These measurements were taken from the skin of the outer arm and the skin of the inner arm, with the latter less likely to be exposed to UV rays than the former.
Those results confirmed that the amount of MFAP-4 was markedly lower in areas that were less exposed to UV in women in their 60s as compared to those in their 20s and 30s.
According to Kao, these findings are the first to confirm that MFAP-4 level in human skin is decreases with ageing.
Furthermore, a comparison between UV-exposed and -unexposed areas of the skin of women in their 60s revealed lower levels of MFAP-4 in exposed areas, confirming that MFAP-4 is reduced by chronic UV exposure.
“The present quantitative results are the first to show that elasticity is low in human skin with reduced expression of MFAP-4, essential for elastin formation, and that its amount is decreased in association with ageing and UV exposure. These findings confirm that MFAP-4 is closely linked with skin elasticity,” said Kao.
“By making use of the findings obtained in the present study, Kao will continue to pursue research of elastin, with the aim to propose technology for realising beautiful and healthy skin.”
Results of this study were presented at the 84th Annual Meeting of the Eastern Division of the Japanese Dermatological Association.