Modulating the expression of survivin and other basal epidermal proteins protects human skin from UVB damage and oxidative stress

Expression of an epidermal growth factor-transdermal peptide fusion protein in Arabidopsis thaliana and its therapeutic effects on skin barrier repair

Epidermal growth factor (EGF) is recognized for its role in regulating keratinocyte proliferation and differentiation, thereby facilitating the restoration of impaired skin barriers. Nevertheless, challenges related to the penetration and safety of EGF remain to be resolved. In this study, we evaluated the efficacy of TDP1, a transdermal peptide, in enhancing the penetration of EGF through murine skin, utilizing EGF expressed in A. thaliana. The coding sequences of the TDP1 and EGF genes were cloned as a fusion construct into a plant expression vector. The resulting plasmid, pGM3301-TDP1-EGF, was introduced into A. thaliana via the floral dip method. Positive clones were identified using polymerase chain reaction (PCR). High-expression strains were selected through Western-blot analysis and enzyme-linked immunosorbent assay (ELISA). Homozygotes plants were obtained through self-pollination. The impact of the TDP1-EGF fusion protein on the restoration of a compromised epidermal barrier was assessed using dermatoscopy. Keratinocyte (KC) proliferation was examined via hematoxylin and eosin (H&E) staining, while KC differentiation, lipid synthesis, and inflammatory factors were analyzed using reverse transcription quantitative PCR (RT-qPCR) and immunohistochemistry. Compared to other expression systems, the A. thaliana system utilized for TDP1-EGF expression offers the advantages of being devoid of toxicity from endogenous plant substances, rendering it both safe and suitable for scalable production of the recombinant protein. The yield of the TDP1-EGF fusion protein expressed in A. thaliana accounted for 0.0166% of the total soluble protein. EGF conjugated with TDP1 displayed enhanced transdermal activity compared to unconjugated EGF, as evidenced by the Franz diffusion cell assay. Furthermore, the biological efficacy of the TDP1-EGF fusion protein surpassed that of EGF alone in ameliorating epidermal barrier damage in a murine skin injury model. This research has the potential to revolutionize the development and delivery of skincare products and establishes a foundation for the application of molecular farming in skin health.

Effect of Ceramides Derivatives from the Peach on Skin Function Improvement in UV-Irradiated Hairless Mice

This study investigated the protective effects of a ceramides derivates from the peach (PF3) on photoaging by UV-irradiated hairless mice. Mice were randomly divided into seven groups: AIN93G without UVB exposure (normal control, NC), AIN93G with UVB exposure (control, C), AIN93G supplemented 100 mg/kg body weight (BW) of L-ascorbic acid with UVB exposure (AA), AIN93G supplemented 100 mg/kg BW of arbutin with UVB exposure (Arbutin), AIN93G supplemented 10 mg/kg BW of PF3 with UVB exposure (10PF3), AIN93G supplemented 20 mg/kg BW of PF3 with UVB exposure (20PF3), and AIN93G supplemented 40 mg/kg BW of PF3 with UVB exposure (40PF3). The study examined the impact of PF3 on skin hydration, wrinkle formation, and melanogenesis using enzyme-linked immunosorbent assay (ELISA), real-time polymerase chain reaction (real-time PCR), and Western blot analysis. The PF3 demonstrated significant protective effects against photoaging by reducing skin wrinkle formation, decreasing epidermal and dermal thickening, and improving skin hydration. It also enhanced the expression of moisture-related factors (hyaluronic acid synthase [HAS], long-chain ceramides [LCBs], dihydroceramide desaturase 1 [DEGS1], and type I collagen [COL1A]) and antioxidant enzyme activities while reducing pro-inflammatory cytokines and oxidative stress markers. The PF3 supplementation positively modulated skin wrinkle formation-related factors, increasing collagen-related gene expression and decreasing matrix metalloproteinases. Additionally, PF3 showed potential in regulating melanogenesis by reducing the nitric oxide and cAMP content, as well as the expression of melanogenesis-related proteins. These comprehensive findings suggest that PF3 supplementation may be an effective strategy for preventing and treating UVB-induced skin photoaging through multiple mechanisms, including improved skin structure, hydration, antioxidant defense, and reduced inflammation and pigmentation.

miR-203 represses keratinocyte stemness by targeting survivin

OBJECTIVE

The epidermis possesses the capacity to replace dying cells and to heal wounds, thanks to resident stem cells, which have self-renewal properties. In skin physiology, miRNAs have been shown to be involved in many processes, including skin and hair morphogenesis. Recently, differentiation of epidermal stem cells was shown to be promoted by the miR-203. The miR-203 is upregulated during epidermal differentiation and is of interest because of significant targets.

METHODS

By utilizing a bioinformatic tool, we identified a target site for miR-203 in the survivin mRNA. Silencing miR-203 was managed with the use of antagomir; the silencing of survivin was performed with a siRNA. Survivin expression was determined by qPCR or immunofluorescence in cultured cells, and by immunohistochemistry in skin sections. Involucrin expression was used as marker of keratinocyte differentiation. A rice extract with previously demonstrated anti-aging properties was evaluated on miR-203 modulation.

RESULTS

In this study, we identified a miR-203/survivin axis, important for epidermal homeostasis. We report that differentiation of keratinocyte is dependent on the level of miR-203 expression and that inhibition of miR-203 can increase the expression of survivin, an epidermal marker of stemness.

CONCLUSION

In summary, our findings suggest that miR-203 target 3'UTR region of survivin mRNA and directly represses survivin expression in the epidermis. The rice extract was identified as modulator of miR-203 and pointed out as a promising microRNA-based strategy in treating skin changes occurring with aging.