Cosmetics (Sep 2024)
A Re-Examination of a Previous Study Relating to Topical Body Formulations: Validating Gene Expression Transcription at Multiple Time Points, and Protein Expression and Translation in an Ex Vivo Model
Abstract
Introduction: This study was conducted to question the findings of a prior study published in Journal of Drugs in Dermatology (JDD) in September 2023, which reported that a topical firming and toning body lotion (FTB—SkinMedica®, Allergan Aesthetics, an AbbVie Company, Irvine, CA, USA) upregulated several genes in a UV-irradiated 3D full-thickness human skin model, outperforming other products, including TransFORM Body Treatment with TriHex Technology® (ATF—Alastin Skincare®, a Galderma company, Fort Worth, TX, USA). Given the unique response reported for FTB, we conducted this study to assess the reproducibility of these results and explore gene expression at multiple time points, along with validating protein expression in an ex vivo model. Materials and Methods: Experiments were conducted using an ex vivo model with photodamaged skin from facelift patients, under an Institutional Review Board-approved study. Skin samples were processed, cultured in transwells with Skin Media, and treated daily with either TransFORM or FTB for 7 days. A control group was left untreated. Gene expression was assessed using RT-PCR on days 1 and 3 and using immunofluorescence after 3 and 7 days of treatment. Skin samples were fixed, paraffin-embedded, sectioned, and stained with an anti-tropoelastin antibody. Fluorescence detection and imaging were conducted to assess protein expression changes. Results: Gene expression data from our study and the initial study showed a few similarities but multiple discrepancies. As opposed to results previously reported at only the 24 h time point, our study was completed at multiple time points and showed a complete reversal of many of these results. For example, COL1A1 expression at 24 h was similar for FTB in both studies but differed for TransFORM, which showed higher levels at 24 h in our study. At day 3, COL1A1 expression decreased markedly for FTB and was sustained for TransFORM. Other genes, such as COL3A1, COL5, ELN, VEGFC, ATG7, ATG12, BECN1, POMP, PSMB5, and PSMB6, exhibited varying expression patterns between the two studies and across different time points. From a translational perspective, histological analysis showed that TransFORM enhanced elastin fiber presence in the dermal–epidermal junction (DEJ) more effectively than FTB at both days 3 and 7. FTB-treated samples maintained a gap in the DEJ, while TransFORM-treated samples exhibited increased cellular proliferation and DEJ undulation, indicative of a healthier regenerative response. Conclusion: This study highlights the problems of examining data and drawing conclusions using a single point of examination. In addition, when a study reports positive results for only one product among a range of eight competitive products, further questioning is essential to exclude the possibility of the experimental model favoring that product. The additional 3-day time point and further translational examination of histological changes paint a completely different picture to that reported in the prior publication. TransFORM outperformed FTB in most gene expressions and histological parameters when assessed over multiple time points in a physiologically relevant ex vivo model.
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