The local hypothalamic-pituitary-adrenal axis in cultured human dermal papilla cells.

BACKGROUND: Stress is an important cause of skin disease, including hair loss. The hormonal response to stress is due to the HPA axis, which comprises hormones such as corticotropin releasing factor (CRF), adrenocorticotropic hormone (ACTH), and cortisol. Many reports have shown that CRF, a crucial stress hormone, inhibits hair growth and induces hair loss. However, the underlying mechanisms are still unclear. The aim of this study was to examine the effect of CRF on human dermal papilla cells (DPCs) as well as hair follicles and to investigate whether the HPA axis was established in cultured human DPCs. RESULTS: CRF inhibited hair shaft elongation and induced early catagen transition in human hair follicles. Hair follicle cells, both human DPCs and human ORSCs, expressed CRF and its receptors and responded to CRF. CRF inhibited the proliferation of human DPCs through cell cycle arrest at G2/M phase and induced the accumulation of reactive oxygen species (ROS). Anagen-related cytokine levels were downregulated in CRF-treated human DPCs. Interestingly, increases in proopiomelanocortin (POMC), ACTH, and cortisol were induced by CRF in human DPCs, and antagonists for the CRF receptor blocked the effects of this hormone. CONCLUSION: The results of this study showed that stress can cause hair loss by acting through stress hormones. Additionally, these results suggested that a fully functional HPA axis exists in human DPCs and that CRF directly affects human DPCs as well as human hair follicles under stress conditions.

CRH receptor antagonists from Pulsatilla chinensis prevent CRH-induced premature catagen transition in human hair follicles.

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.

Anti-aging Properties of Conditioned Media of Epidermal Progenitor Cells Derived from Mesenchymal Stem Cells.

INTRODUCTION: Reduced number and activities of epidermal stem cells are related to the features of photoaged skin. It was reported that conditioned media from various stem cell cultures are capable of improving the signs of cutaneous aging. This work was performed to establish epidermal progenitor cells derived from mesenchymal stem cells, and to evaluate the anti-aging efficacy of its conditioned media. METHODS: Epidermal progenitor cell culture was established by differentiation from mesenchymal stem cells, and its conditioned medium (EPC-CM) was prepared. Normal human dermal fibroblasts were exposed to hydrogen peroxide and the protective effects of EPC-CM were investigated, monitoring intracellular reactive oxygen species (ROS), cellular defense enzymes, collagen biosynthesis, and mitogen-associated protein kinase (MAPK) signaling. Anti-aging efficacy of cosmetic essence (5% EPC-CM) was evaluated by a clinical test with 25 Korean women aged between 29 and 69. RESULTS: Hydrogen peroxide hindered proliferation of fibroblasts and increased the levels of intracellular ROS. Pretreatment of EPC-CM protected fibroblasts from oxidative stress as shown by accelerated proliferation and reduced ROS generation. EPC-CM effectively prevented hydrogen peroxide-induced alterations of the activities, as well as mRNA and protein levels, of antioxidative enzymes, such as superoxide dismutase, catalase, and glutathione peroxidase. Reduced type I collagen biosynthesis and stimulated phosphorylation of MAPK signaling proteins, induced by oxidative damage, were also prevented by EPC-CM. In clinical study, wrinkle, depression, and skin texture were improved by the topical application of a formulation containing 5% EPC-CM within 4 weeks. CONCLUSION: Epidermal progenitor cell culture was established, and its conditioned medium was developed for anti-aging therapy. EPC-CM improved signs of skin aging in clinical study, possibly via activation of cellular the defense system, as supported by in vitro results.

Identification and bacterial characteristics of Xenorhabdus hominickii ANU101 from an entomopathogenic nematode, Steinernema monticolum.

An entomopathogenic nematode, Steinernema monticolum, was collected in Korea. Its identity was confirmed by morphological and molecular characters. Its symbiotic bacterium, Xenorhabdus hominickii ANU101, was isolated and assessed in terms of bacterial characteristics. Sixty-eight different carbon sources were utilized by X. hominickii ANU101 out of 95 different sources from a Biolog assay. Compared to other Xenorhabdus species, X. hominickii ANU101 was relatively susceptible to high temperatures and did not grow above 34°C. Furthermore, its growth rate was much slower than other Xenorhabdus species. X. hominickii exhibited insecticidal activities against coleopteran, dipteran, and lepidopteran insect pests. The bacterial virulence was not correlated with its host nematode virulence with respect to relative insecticidal activity against target insects. X. hominickii ANU101 exhibited antibiotics tolerance. The bacterium possesses four different plasmids (Xh-P1 (104,132bp), Xh-P2 (95,975bp), Xh-P3 (88,536bp), and Xh-P4 (11,403bp)) and encodes 332 open reading frames. Subsequent predicted genes include toxin/antitoxins comprising a multidrug export ATP-binding/permease. This study reports bacterial characters of X. hominickii and its entomopathogenicity.

Rosiglitazone-mediated dendritic cells ameliorate collagen-induced arthritis in mice.

Rosiglitazone is a selective ligand for peroxisome proliferator-activated receptor-gamma (PPAR-γ), which serves diverse biological functions. A number of autoimmune disease models have been used to examine the anti-inflammatory and immunosuppressive effects of tolerogenic dendritic cells (tDCs). The aim of the present study was to investigate whether rosiglitazone-mediated DC (Rosi-DC) therapy suppressed arthritis in a collagen-induced arthritis (CIA) mouse model. Rosi-DCs were generated by treating immature DCs with TNF-α, type II collagen, and rosiglitazone. CIA mice then received subcutaneously (s.c.) two injections of Rosi-DCs. The severity of arthritis was then assessed histopathologically. The phenotypes of the DC and regulatory T (Treg) cell populations in CIA mice were determined by flow cytometry and the effect of Rosi-DCs on the secretion of autoimmunity-inducing cytokines was examined by ELISA. Rosi-DCs expressed lower levels of DC-related surface markers than mature DCs. Histopathological examination revealed that the degree of inflammation in the paws of Rosi-DC-treated mice was much lower than that in the paws of PBS-treated CIA mice. Taken together, these results clearly show that rosiglitazone-mediated DCs ameliorate CIA, most likely via the induction of antigen-specific Treg cells.

Lysophosphatidic acid increases the proliferation and migration of adipose­derived stem cells via the generation of reactive oxygen species.

Phospholipid derivatives, such as lysophosphatidic acid (LPA), exhibit mitogenic effects on mesenchymal stem cells; however, the molecular mechanism underlying this stimulation has yet to be identified. The aims of the present study were as follows: To evaluate the stimulatory effects of LPA on the proliferation and migration of adipose­derived stem cells (ASCs); to study the association between reactive oxygen species (ROS) and LPA signaling in ASCs; and to investigate the microRNAs upregulated by LPA treatment in ASCs. The results of the present study demonstrated that LPA increased the proliferation and migration of ASCs, and acted as a mitogenic signal via extracellular signal­regulated kinases 1/2 and the phosphoinositide 3­kinase/Akt signaling pathways. The LPA1 receptor is highly expressed in ASCs, and pharmacological inhibition of it by Ki16425 significantly attenuated the proliferation and migration of ASCs. In addition, LPA treatment generated ROS via NADPH oxidase 4, and ROS were able to function as signaling molecules to increase the proliferation and migration of ASCs. The induction of ROS by LPA treatment also upregulated the expression of miR­210. A polymerase chain reaction array assay demonstrated that the expression levels of adrenomedullin and Serpine1 were increased following treatment with LPA. Furthermore, transfection with Serpine1­specific small interfering RNA attenuated the migration of ASCs. In conclusion, the present study is the first, to the best of our knowledge, to report that ROS generation and miR­210 expression are associated with the LPA­induced stimulation of ASCs, and that Serpine1 mediates the LPA­induced migration of ASCs. These results further suggest that LPA may be used for ASC stimulation during stem cell expansion.

Hair-growth-promoting effect of conditioned medium of high integrin α6 and low CD 71 (α6bri/CD71dim) positive keratinocyte cells.

Keratinocyte stem/progenitor cells (KSCs) reside in the bulge region of the hair follicles and may be involved in hair growth. Hair follicle dermal papilla cells (HFDPCs) and outer root sheath (ORS) cells were treated with conditioned medium (CM) of KSCs. Moreover, the effects of KSC-CM on hair growth were examined ex vivo and in vivo. A human growth factor chip array and RT-PCR were employed to identify enriched proteins in KSC-CM as compared with CM from keratinocytes. KSC-CM significantly increased the proliferation of HFDPCs and ORS cells, and increased the S-phase of the cell cycle in HFDPCs. KSC-CM led to the phosphorylation of ATK and ERK1/2 in both cell types. After subcutaneous injection of KSC-CM in C3H/HeN mice, a significant increase in hair growth and increased proliferation of hair matrix keratinocytes ex vivo was observed. We identified six proteins enriched in KSC-CM (amphiregulin, insulin-like growth factor binding protein-2, insulin-like growth factor binding protein-5, granulocyte macrophage-colony stimulating factor, Platelet-derived growth factor-AA, and vascular endothelial growth factor). A growth-factor cocktail that contains these six recombinant growth factors significantly increased the proliferation of HFDPCs and ORS cells and enhanced the hair growth of mouse models. These results collectively indicate that KSC-CM has the potential to increase hair growth via the proliferative capacity of HFDPCs and ORS cells.

Efficacy of microneedling plus human stem cell conditioned medium for skin rejuvenation: a randomized, controlled, blinded split-face study.

BACKGROUND: The use of growth factors in skin rejuvenation is emerging as a novel anti-aging treatment. While the role of growth factors in wound healing is well established, their use in skin rejuvenation has only recently been to be studied and no controlled trials have been performed. OBJECTIVE: We evaluated the anti-aging effects of secretory factors of endothelial precursor cells differentiated from human embryonic stem cells (hESC-EPC) in Asian skin. METHODS: A total of 25 women were included in this randomized, controlled split-face study. The right and left sides of each participant's face were randomly allocated to hESC-EPC conditioned medium (CM) or saline. To enhance epidermal penetration, a 0.25-mm microneedle roller was used. Five treatment sessions were repeated at 2-week intervals. RESULTS: Physician's global assessment of pigmentation and wrinkles after treatment revealed statistically significant effects of microneedling plus hESC-EPC CM compared to microneedling alone (p<0.05). Skin measurements by Mexameter and Visiometer also revealed statistically significant effects of microneedling plus hESC-EPC CM on both pigmentation and wrinkles (p<0.05). The only minimal adverse event was mild desquamation in one participant. CONCLUSION: Secretory factors of hESC-EPC improve the signs of skin aging and could be a potential option for skin rejuvenation.

Cellular and molecular stimulation of adipose-derived stem cells under hypoxia.

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.

Screening of Kit inhibitors: suppression of Kit signaling and melanogenesis by emodin.

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 (IC(50) = 4.9 and 9.0 microM, 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 microM 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.

Cardamonin suppresses melanogenesis by inhibition of Wnt/beta-catenin signaling.

Wnt/beta-catenin signaling plays important roles in many developmental processes, including neural crest-derived melanocyte development. Here we show that cardamonin, a calchone from Aplinia katsumadai Hayata, inhibited pigmentation in melanocytes through suppression of Wnt/beta-catenin signaling pathway. Cardamonin significantly suppressed the expression of microphthalmia-associated transcription factor (MITF) and tyrosinase, which are melanocyte differentiation-associated markers, in human normal melanocytes, thereby decreasing intracellular melanin production. In addition, cardamonin promoted the degradation of intracellular beta-catenin that was accumulated by Wnt3a-conditioned medium (Wnt3a CM) or bromoindirubin-3'-oxime (BIO), a glycogen synthase kinase-3beta (GSK-3beta) inhibitor, in HEK293 reporter cells and human normal melanocytes. Our findings indicate that cardamonin may be a potential whitening agent for use in cosmetics and in the medical treatment of hyperpigmentation disorders.

Anti-wrinkling effects of the mixture of vitamin C, vitamin E, pycnogenol and evening primrose oil, and molecular mechanisms on hairless mouse skin caused by chronic ultraviolet B irradiation.

BACKGROUND: Naturally occurring antioxidants were used to regulate the skin damage caused by ultraviolet (UV) radiation because several antioxidants have demonstrated that they can inhibit wrinkle formation through prevention of matrix metalloproteinases (MMPs) and/or increase of collagen synthesis. OBJECTIVE: We examined the effect of oral administration of the antioxidant mixture of vitamin C, vitamin E, pycnogenol, and evening primrose oil on UVB-induced wrinkle formation. In addition, we investigated the possible molecular mechanism of photoprotection against UVB through inhibition of collagen-degrading MMP activity or through enhancement of procollagen synthesis in mouse dorsal skin. METHODS: Female SKH-1 hairless mice were orally administrated the antioxidant mixture (test group) or vehicle (control group) for 10 weeks with UVB irradiation three times a week. The intensity of irradiation was gradually increased from 30 to 180 mJ/cm2. Microtopographic and histological assessment of the dorsal skins was carried out at the end of 10 weeks to evaluate wrinkle formation. Western blot analysis and EMSA were also carried out to investigate the changes in the balance of collagen synthesis and collagen degradation. RESULTS: Our antioxidant mixture significantly reduced UVB-induced wrinkle formation, accompanied by significant reduction of epidermal thickness, and UVB-induced hyperplasia, acanthosis, and hyperkeratosis. This antioxidant mixture significantly prevented the UVB-induced expressions of MMPs, mitogen-activated protein (MAP) kinase, and activation of activator protein (AP)-1 transcriptional factor in addition to enhanced type I procollagen and transforming growth factor-beta2 (TGF-beta2) expression. CONCLUSION: Oral administration of the antioxidant mixture significantly inhibited wrinkle formation caused by chronic UVB irradiation through significant inhibition of UVB-induced MMP activity accompanied by enhancement of collagen synthesis.

Establishment of type II 5alpha-reductase over-expressing cell line as an inhibitor screening model.

Dihydrotestosterone (DHT) is the most potent male hormone that causes androgenetic alopecia. The type II 5alpha-reductase is an enzyme that catalyzes the conversion of testosterone (T) to DHT, therefore it can be expected that specific inhibitors for type II 5alpha-reductase may improve the pathophysiologic status of androgenetic alopecia. In this study, we attempted to establish the reliable and convenient screening model for type II 5alpha-reductase inhibitors. After transfection of human cDNA for type II 5alpha-reductase into HEK293 cells, the type II 5alpha-reductase over-expressing stable cells were selected by G418 treatment. RT-PCR and Western blot analyses confirmed that type II 5alpha-reductase gene was expressed in the stable cells. In in vitro enzymatic assay, 10 microg of stable cell extract completely converted 1 microCi (approximately 0.015 nmol) of T into DHT. The type II 5alpha-reductase activity was inhibited by finasteride in a dose-dependent manner, confirming the reliability of screening system. In cell culture condition, 2 x 10(5) of stable cells completely converted all the input T (approximately 0.03 nmol) into DHT by 4h incubation, demonstrating that the stable cell line can be used as a cell-based assay system. Using this system, we selected the extracts of Curcumae longae rhizoma and Mori ramulus as the potential inhibitors for type II 5alpha-reductase. These results demonstrate that the type II 5alpha-reductase over-expressing stable cell line is a convenient and reliable model for screening and evaluation of inhibitors.

Inhibition of melanogenesis by selina-4(14),7(11)-dien-8-one isolated from Atractylodis Rhizoma Alba.

To develop effective skin-lightening agents, we tested medicinal herbal extracts for their melanogenic-inhibitory activities. We isolated a sesquiterpenoid compound from the extract of Atractylodis Rhizoma Alba using the bioactivity-guided fractionation and identified it as selina-4(14),7(11)-dien-8-one (compound 1) with spectroscopic methods. Compound 1 dramatically reduced melanin synthesis of melan-a cells without any apparent cytotoxicity. Compound 1 did not inhibit cell-free tyrosinase activity but decreased tyrosinase activity in melanocytes. These effects were attributed to reduced expression of melanogenic enzymes such as tyrosinase, tyrosinase-related protein 1 (TRP-1), and tyrosinase-related protein 2 (TRP-2). These results suggest that compound 1 may be an effective skin-lightening agent that regulates expression of melanogenic enzymes.

Partially purified paeoniflorin exerts protective effects on UV-induced DNA damage and reduces facial wrinkles in human skin.

Partially purified paeoniflorin (PF), a new cosmetic ingredient from roots of Paeoniae lactiflora, has been developed. Its paeoniflorin content is about 64%, far higher than that of conventional, cosmetic-grade peony root extracts (approximately 10%). In this report, we studied the effects of PF on UV-induced DNA damage in both cultured human keratinocytes and hairless mouse skin. We also investigated the anti-wrinkle effects of PF-containing cosmetic preparations on human skin. From the in vitro and in vivo comet assay, it was revealed that PF protected cells from DNA damage induced by ultraviolet B (UVB) irradiation in both cultured normal human keratinocytes (19.4% decrease at 0.001%) and hairless mouse skin keratinocytes (41% decrease at 0.01%). An eight-week clinical trial using 0.5% PF-containing formulation with 20 volunteers resulted in a statistically significant reduction in facial wrinkles (p < 0.05). These results suggest that the partially purified paeoniflorin has potent anti-aging and anti-wrinkle activities and should be a useful ingredient for these purposes.