Development of a method for evaluating skin dullness: A mathematical model explaining dullness by the color, optical properties, and microtopography of the skin.

BACKGROUND: Skin dullness has long been a major concern of Japanese women. It is usually evaluated and judged visually by experts. Although several factors are recognized to play a role, it is unclear to what extent such physiological characteristics contribute to skin dullness. The purpose of this study is to establish an objective method for evaluation, which will assist in developing cosmetics products targeting skin dullness. METHODS: We conducted a skin measurement study on 50 Japanese women in their 30-50s, where skin dullness was visually assessed by a group of experts to obtain an average dullness score, and several skin parameters were obtained. We then developed a regression model that explains the visual assessment score using these physiological parameters. RESULTS: The results of partial least squares analysis of the dullness perception and physiological characteristics showed that skin dullness can be defined by colorimetric, optical, and skin surface microtopography parameters. Additionally, the contribution of each parameter to the model was determined. Our results suggest that dullness perception is highly affected by the melanin content and yellowness of the skin, followed by skin reddishness, roughness, and translucency score, whereas glossiness has less effect. Strikingly, the contribution ratio of each parameter varied among age groups. Furthermore, we confirmed that the predicted value of skin dullness increases with age. CONCLUSION: Our results will help the design of cosmetics targeting factors specific to age groups in developing effective solutions for skin dullness.

Deep Imaging Analysis in VISUAL Reveals the Role of YABBY Genes in Vascular Stem Cell Fate Determination.

Stem cells undergo cell division and differentiation to ensure organized tissue development. Because plant cells are immobile, plant stem cells ought to decide their cell fate prior to differentiation, to locate specialized cells in the correct position. In this study, based on a chemical screen, we isolated a novel secondary cell wall indicator BF-170, which binds to lignin and can be used to image in vitro and in situ xylem development. Use of BF-170 to observe the vascular differentiation pattern in the in vitro vascular cell induction system, VISUAL, revealed that adaxial mesophyll cells of cotyledons predominantly generate ectopic xylem cells. Moreover, phloem cells are abundantly produced on the abaxial layer, suggesting the involvement of leaf adaxial-abaxial polarity in determining vascular cell fate. Analysis of abaxial polarity mutants highlighted the role of YAB3, an abaxial cell fate regulator, in suppressing xylem and promoting phloem differentiation on the abaxial domains in VISUAL. Furthermore, YABBY family genes affected in vivo vascular development during the secondary growth. Our results denoted the possibility that such mediators of spatial information contribute to correctly determine the cell fate of vascular stem cells, to conserve the vascular pattern of land plants.

Ectopic Vascular Induction in Arabidopsis Cotyledons for Sequential Analysis of Phloem Differentiation.

Vascular system is vital for the transport of water and nutrients as well as for providing mechanical support in many land plants. Plant transcription factors play a central role in regulating vascular development downstream of hormones and peptide signaling pathways. Particularly, cell culture systems have contributed to isolating such key transcription factors for xylem differentiation. However, there had been no efficient systems that can mimic phloem differentiation in the model plant Arabidopsis, preventing the identification of phloem-related transcription factors. We have recently established Vascular cell Induction culture System Using Arabidopsis Leaves (VISUAL), which concomitantly generates both xylem and phloem cells in the cotyledon of Arabidopsis. This system can be used to take a closer look at the bi-directional differentiation mechanism of (pro)cambial cells into xylem and phloem cells. Here, we report the methods of microscopic, genetic, and molecular analysis using VISUAL, which can help in decrypting the transcriptional networks that regulate vascular cell differentiation.

Tissue Culture for Xylem Differentiation with Arabidopsis Leaves.

Culture systems combined with molecular biological approaches have identified various key factors regulating vascular differentiation, which makes a great contribution to development of vascular biology. Recently, we established a novel culture system for xylem cell differentiation in the model plant Arabidopsis thaliana (Arabidopsis), in which ectopic xylem cells can be induced throughout leaf disks within 3-4 days. Here we describe detailed procedures of the culture system from sample preparation to vascular cell induction culture.

Vascular Cell Induction Culture System Using Arabidopsis Leaves (VISUAL) Reveals the Sequential Differentiation of Sieve Element-Like Cells.

Cell differentiation is a complex process involving multiple steps, from initial cell fate specification to final differentiation. Procambial/cambial cells, which act as vascular stem cells, differentiate into both xylem and phloem cells during vascular development. Recent studies have identified regulatory cascades for xylem differentiation. However, the molecular mechanism underlying phloem differentiation is largely unexplored due to technical challenges. Here, we established an ectopic induction system for phloem differentiation named Vascular Cell Induction Culture System Using Arabidopsis Leaves (VISUAL). Our results verified similarities between VISUAL-induced Arabidopsis thaliana phloem cells and in vivo sieve elements. We performed network analysis using transcriptome data with VISUAL to dissect the processes underlying phloem differentiation, eventually identifying a factor involved in the regulation of the master transcription factor gene APL Thus, our culture system opens up new avenues not only for genetic studies of phloem differentiation, but also for future investigations of multidirectional differentiation from vascular stem cells.

Androgenic pathways in the progression of triple-negative breast carcinoma: a comparison between aggressive and non-aggressive subtypes.

One of the active intracellular pathways/networks in triple-negative breast carcinoma (TNBC) is that of the androgen receptor (AR). In this study, we examined AR and androgen-metabolising enzyme immunoreactivity in subcategories of TNBC to further elucidate the roles of androgenic pathways in TNBC. We utilised formalin-fixed paraffin-embedded breast cancer samples from ductal carcinoma in situ (DCIS) and invasive ductal carcinoma patient cohorts. We then used immunohistochemistry to classify these samples into basal-like and non-basal samples and to assess interactions between AR, androgen-metabolising enzymes and proliferation. To further substantiate our hypothesis and provide mechanistic insights, we also looked at the expression and regulation of these factors in publically available microarray data and in a panel of TNBC AR-positive cell lines. DCIS was associated with higher levels of AR and enzymes (p < 0.02), although a similar difference was not noticed in basal and non-basal samples. AR and enzymes were correlated in all states. In TNBC cell lines (MDA-MD-453, MFM-223 and SUM185-PE), we found that DHT treatment up-regulated 5αR1 and 17ßHSD5 suggesting a mechanistic explanation for the correlations observed in the histological samples. Publicly available microarray data in TNBC cases suggested similar patterns to those observed in histological samples. In the majority of settings, including publically available microarray data, an inverse association between AR and proliferation was detected. These findings suggest that decreases in AR and androgen-metabolising enzymes may be involved in the increased biological aggressiveness in TNBC development.