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Background: There is a growing interest in the relationship among stress hormones, neuroendocrine signaling, and skin diseases, including hair loss. Previous reports showed that stress hormones inhibit human hair growth and induce early catagen transition. Moreover, a CRH receptor antagonist reversed CRH‐induced alopecia in a mouse model, suggesting that antagonization of the CRH receptor is a key clinical strategy to treat stress‐induced hair loss. Objectives: The aim of this study was to investigate the protective effect of CRH receptor antagonists from Pulsatilla chinensis on human hair follicles (hHFs) and human dermal papilla cells (hDPCs). Methods: hHFs were observed and scored by hair cycle. The levels of cAMP, a second messenger, were measured in each group. In addition, the mRNA and protein levels of factors related to the hair cycle were measured. Furthermore, the expression levels of various members of the mitogen‐activated protein kinase (MAPK) signaling pathway related to stress were measured. Results: CRH induced early catagen transition in an ex vivo hair organ culture model. In addition, CRH downregulated the levels of alkaline phosphatase (ALP) and hair anagen‐related cytokines in cultured hDPCs. Moreover, CRH induced the phosphorylation of JNK, c‐Jun, p38, ERK, and Akt in cultured hDPCs. CRH receptor antagonists isolated from P chinensis reversed these CRH‐induced modulations in both ex vivo hair follicles (HFs) and cultured hDPCs. Conclusions: These results indicate that P chinensis effectively blocks CRH receptor function and that saponin derivatives from P chinensis could be a pharmaceutical and cosmetic approach to treat stress‐induced hair loss. [ABSTRACT FROM AUTHOR]

2D materials, specifically MoS2 semiconductors, have received tremendous attention for photo‐sensing applications due to their tunable bandgap and low noise levels. A unique photodetector using multilayer MoS2 as the semiconductor channel, in which the gate electrode of the device is permanently connected to the grounded source electrode to introduce rectification, is reported. The proposed grounded‐gate photodiode exhibits high photoresponsivity of 1.031 A W−1, excellent photodetectivity (>6 × 1010 jones), and highly stable rise/fall time response (100–200 ms) under illumination of visible light (at the wavelengths of 405, 532, and 638 nm). Numerical device simulations using quantum transport methods and photoconductive effects are used to explain the device operation. It is also suggested that the gate metal work function can be carefully chosen to increase the sensitivity of the grounded‐gate photodetector by suppressing the dark current. The grounded‐gate device proposed, owing to the properties of rectifying behavior, low contact resistance, consistent photoresponsivity, and linear sensitivity, provides a new platform for next‐generation applications in the field of electronics and optoelectronics. [ABSTRACT FROM AUTHOR]

Cultivation under hypoxia has beneficial effects on adipose-derived stem cells (ASCs). Despite a history of extensive research on the responses of ASCs to hypoxia, investigations have focused on functional alterations of ASCs. Therefore, we provide novel insight in this review into the cellular and molecular changes that occur in ASCs under hypoxic conditions. Hypoxia increases the proliferation and migration of ASCs by the generation of reactive oxygen species (ROS) and downstream phosphorylation of platelet-derived growth factor receptor-beta, ERK1/2, and Akt. Chronically, activation of these signaling pathways upregulates miR-210 via phosphorylation of NF-κB and Elk1. Protein tyrosine phosphatase, non-receptor type 2 (PTPN2) is a direct miR-210 target, and downregulation of PTPN2 mediates the proliferation and migration of ASCs during hypoxia. In addition, the paracrine effect of ASCs is enhanced under hypoxic conditions, irrespective of whether ROS are generated. Hypoxic preconditioning stabilizes hypoxia inducible factor-1α under hypoxic conditions and increases secretion of vascular endothelial growth factor, thereby improving the regenerative potential of ASCs. Therefore, understanding the cellular and molecular changes that occur during hypoxia is highly relevant for the development of novel ASC therapies. [ABSTRACT FROM AUTHOR]

In search of novel antipigmentation agents, a set of 3,840 compounds with natural-like synthetic or natural origin were screened against Kit (stem cell factor receptor). Emodin from the seed of Cassia tora and baicalin from Scutellariae radix showed potent inhibitory effects (IC50 = 4.9 and 9.0 mm, respectively) on the phosphorylation of Kit. Emodin also blocked other receptor tyrosine kinase activities, such as epithelial growth factor receptor (EGFR), vascular endothelial growth factor receptor 2 (VEGFR-2), fibroblast growth factor receptor 1 (FGFR-1), platelet-derived growth factor receptor b (PDGFR-b). In contrast to emodin, aloe-emodin did not inhibit Kit activity at all. Emodin also blocked the cellular kinase activities of Kit and its down-stream p44/42 mitogen activated protein kinase (MAPK) in MO7e cells and human primary melanocytes. Emodin strongly suppressed the melanin synthesis triggered by stem cell factor (SCF) treatment. Also, emodin showed almost no toxicity up to 10 mm on cultured melanocytes as reported previously by other researchers. The results indicate that emodin is a good candidate for the development of antipigmentation agents since it can radically block the differentiation and proliferation of pigment cells by reducing Kit signaling. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]