PKCι is a target of 7,8,4′‐trihydroxyisoflavone for the suppression of UVB‐induced MMP‐1 expression

Abstract

The soy isoflavone daidzein is bioconverted to 7,8,4'-trihydroxyisoflavone (7,8,4'-THIF) by microorganisms. Here, we investigated the matrix metalloproteinase (MMP)-1 inhibitory properties of 7,8,4'-THIF that arise through the suppression of UVB-induced MMP-1 expression. 7,8,4'-THIF reduced UVB-induced MMP-1 expression at the transcriptional level in primary human dermal fibroblasts and inhibited UVB-induced transcriptional activity of AP-1, a major activator of MMP-1 expression. Additionally, it was observed that the mitogen-activated protein kinase (MAPK) pathway, a crucial signalling cascade for MMP-1 expression, was suppressed by 7,8,4'-THIF. Protein kinase C iota (PKCι) was suspected to be a direct target of 7,8,4'-THIF. The direct interaction between 7,8,4'-THIF and PKCι was confirmed using pull-down assays and immobilized metal ion affinity-based fluorescence polarization assays. Finally, we observed that 7,8,4'-THIF inhibited UVB-induced MMP-1 expression in a human skin equivalent model. Taken together, these results suggest that 7,8,4'-THIF, a bioconversion product of daidzein, suppresses UVB-induced MMP-1 expression.

Penta-1,2,3,4,6-O-Galloyl-β-d-Glucose Inhibits UVB-Induced Photoaging by Targeting PAK1 and JNK1

“…Histological studies have shown that photoaged skin is associated with increased epidermal thickness and changes in the organization of connective tissue [26,50]. Similarly, we found that chronic UVB induced epidermal thickening in mouse skin, while PGG inhibited the increase in epidermal thickness.…”

“…Since elevated MMP-1 levels are closely associated with photoaging [28], we investigated the effects of PGG on UVB-induced MMP-1 expression in HaCaT cells. It has been well-reported that UVB strongly induced MMP-1 mRNA and protein level and subsequently MMP-1 was secreted into culture media in cell model systems [26,27,29,30]. In contrast, changes in MMP-2 mRNA and protein levels by UVB irradiation were not observed or very slightly increased in human keratinocytes [27,28].…”

“…Epidermal thickness is used as a quantitative parameter to assess skin photoaging [26,38]. Therefore, we evaluated the effect of PGG on UVB-induced epidermal thickening (Figure 6).…”

“…Following hybridization with the secondary antibody, protein bands were visualized using an Amersham enhanced chemiluminescence (ECL) plus western blotting detection system (Piscataway, NJ, USA). MMP-2, GAPDH or β-actin was used as loading control according to previous study [26,27].…”

Beneficial effects on skin health using polysaccharides from red ginseng by‐product

“…Repeated sUV exposure promotes matrix metalloproteinases (MMPs), the expression and activity which are regulated by AP‐1, a transcription factor activated by sUV irradiation (Wang & Dreesen, ). Of these AP‐1‐regulated MMPs, the collagenase MMP‐1 plays important roles in the degradation of type 1 and type 3 collagen within the skin (Lim et al, ). MMP‐1 is overexpressed after UV exposure, and it has been reported that the occurrence of skin wrinkles is alleviated when its expression is blocked (Han et al, ).…”