Evaluation of the 52-week chronic toxicity of a novel phthalate-free plasticizer, Eco-DEHCH (bis(2-ethylhexyl) cyclohexane-1,4-dicarboxylate), in Han Wistar rats.

Phthalate esters (PEs) are the most widely used class of plasticizers. Several PEs, however, were found to have adverse effects on the health of animals. A new phthalate-free plasticizer, Eco-DEHCH (bis(2-ethylhexyl) cyclohexane-1,4-dicarboxylate), was recently developed as an ecofriendly replacement for phthalate plasticizers and to be less harmful to organisms. The present study evaluated the long-term toxicity of Eco-DEHCH in Wistar Han rats to explore adverse effects and predict hazardous potential to humans. Forty male and forty female Wistar Han rats were exposed to Eco-DEHCH in dietary feed for 52 weeks, and their hematologic, coagulation, and serum biochemical parameters were monitored. The rats were subjected to close clinical, ophthalmic, and histopathologic examinations and urinalysis throughout the consumption of Eco-DEHCH. The effects of this plasticizer on food consumption and organ weight were also determined. Chronic exposure to Eco-DEHCH was generally safe, although it also resulted in α2u-globulin accumulation, a parameter with no human relevance. In conclusion, Eco-DEHCH can serve as a safe and promising alternative plasticizer.

Alteration of microRNA profiling in sphere-cultured ovarian carcinoma cells.

Ovarian cancer is an aggressive and lethal cancer, which in part, can be attributed to complications in the effective detection of this disease during early stages of progression. Frequently, epithelial ovarian cancer is disseminated to the abdominal cavity and forms multicellular aggregates. This unique early metastatic event, and formation of the multicellular aggregate is implicated to provide a basis for understanding the underlying molecular mechanisms of metastasis in ovarian cancer. Therefore, a 3-dimensional (3D) sphere culture system was established in the present study to mimic the later stages of ovarian cancer. The aim of the present study was to investigate whether microRNAs (miRNAs), which have functions in metastasis and chemoresistance in various cancer models, are altered in ovarian cancer cells by 3-dimensional (3D) culture. A multicellular aggregate of SKOV3ip1 ovarian carcinoma cells was generated using a 3D sphere culture system. Cell viability analysis demonstrated that the sphere-cultured SKOV3ip1 cells exhibited chemoresistance compared with those in a conventional 2-dimensional (2D) monolayer cultured SKOV3ip1 system. Under the same experimental conditions, 71 upregulated miRNAs and 63 downregulated miRNAs were identified in the 3D sphere-cultured SKOV3ip1 cells. The predicted targets of the 3D sphere-culture specific miRNAs were further identified using PITA, microRNAorg and TargetScan. Compared with the target gene pool and Kyoto Encyclopedia of Genes and Genomes pathway, the present study provides evidence that the 3D sphere culture-specific miRNAs regulated sphere formation and chemoresistance in 3D sphere-cultured SKOV3ip1 cells. Overall, the results of the present study demonstrated that miRNA-mediated regulation is implicated to provoke features of SKOV3ip1 multicellular aggregation, including sphere formation and chemoresistance.

Poria cocos Wolf extracts represses pigmentation in vitro and in vivo.

In skin, melanocytes determine skin color using melanogenesis, which induces protective mechanism to oxidative stress and UV damage. However, when melanin is excessive produced by the various stimulus, the accumulated melanin induces hyperpigmentation disease such as melasma, freckles, Melanism ware induced. Therefore, it is implicated to finding potential agents for whitening to be used in cosmetic products. In our present study, we show that Poria cocos Wolf extracts decreased melanin synthesis in B16F10. And then this inhibition of melanogenesis was provoked by regulation of tyrosinase activity and tyrosinase and MITF expression. Moreover, Poria cocos Wolf extracts contained cream improved skin tone using increase of bright value. Overall, these results provide evidence to potential agent for whitening to be used in cosmetic products.

MicroRNA­378b regulates α­1­type 1 collagen expression via sirtuin 6 interference.

Ultraviolet (UV) light mediates skin aging and induces destruction of the dermis by modulating the expression levels of extracellular matrix­associated genes, including collagen and matrix metalloproteinases. Sirtuin 6 (SIRT6), a member of the sirtuin family of proteins, regulates collagen metabolism and is an established anti­aging protein. However, the exact underlying mechanism by which SIRT6 expression is regulated in dermal fibroblasts during the aging process is unclear. The present study demonstrated that expression of microRNA­378b (miR­378b) is induced in UVB­exposed human dermal fibroblasts (HDFs), and this was inversely associated with the mRNA expression levels of α­1­type 1 collagen (COL1A1). In addition, knockdown of miR­378b enhanced the mRNA expression levels of COL1A1 in HDFs. A target analysis for miR­378b was performed, and the results revealed that SIRT6, a regulator of COL1A1, contains a target sequence for miR­378b in its 3'untranslated region. Notably, the present study demonstrated that an miR­378b mimic and inhibitor may directly regulate SIRT6 expression in HDFs. In conclusion, the present study suggested that miR­378b represses the mRNA expression levels of COL1A1 via interference with SIRT6 in HDFs, and may contribute to the underlying molecular mechanism by which UVB inhibits collagen I in dermal fibroblasts.

Arctiin regulates collagen type 1α chain 1 mRNA expression in human dermal fibroblasts via the miR­378b­SIRT6 axis.

Arctiin, a lignin isolated from Arctium lappa, exhibits a variety of biological effects, including anti­viral, anti­inflammatory, and anti­proliferative actions, in mammalian cells. In a previous study, arctiin was demonstrated to induce procollagen type I synthesis and exhibited protective effects against ultraviolet B (UVB) radiation in normal human dermal fibroblasts (nHDFs). However, the underlying molecular mechanism of arctiin­mediated collagen synthesis remains unknown. In the present study, the mechanism for increased expression of collagen type 1α 1 chain (COL1A1) mRNA in arctiin­induced nHDFs was identified. The expression of microRNA­378b (miR­378b), downregulated by arctiin, was correlated with the expression of sirtuin­6 (SIRT6) mRNA, a regulator of COL1A1 mRNA. Furthermore, it was revealed that arctiin protected the UVB radiation­mediated decrease in COL1A1 mRNA expression, through the miR­378b/SIRT6 signaling pathway. In conclusion, these results suggest that arctiin regulates COL1A1 through the miR­378b­SIRT6 axis.

Selective FGFR inhibitor BGJ398 inhibits phosphorylation of AKT and STAT3 and induces cytotoxicity in sphere-cultured ovarian cancer cells.

Epithelial ovarian cancer is the most aggressive and lethal among the gynecological malignancies, which is often found disseminated to peritoneal cavity at the time of diagnosis. There is accumulating evidence on the existence of genetic alteration and amplification of fibroblast growth factor receptor (FGFR) in various cancers. Also the aberrated FGFR/FGF signaling has been implicated in cancer development and tumor microenvironment. However, the antitumor activity of BGJ398, a selective inhibitor of FGFR 1/2/3 against ovarian cancer still remains unknown. The aim of the present study is to evaluate the antitumoral activity of BGJ398 on ovarian cancer cell line SKOV3ip1 using 3-dimensional (3D) sphere culture system which has been accepted as a better mimic in vivo microenvironment than conventional 2-dimensional (2D) monolayer culture system. We examined the differential expression features of key signaling molecules which have a role in cell survival and proliferation between sphere-cultured SKOV3ip1 cells and monolayer-cultured SKOV3ip1 cells. The phosphorylation of AKT and signal transducer and activator of transcription 3 (STAT3) known as survival signaling molecules were upregulated in sphere-cultured SKOV3ip1 cells compared to in monolayer-cultured SKOV3ip1 cells. Next, we evaluated the antitumor activity of BGJ398 in monolayer-cultured SKOV3ip1 cells or sphere-cultured SKOV3ip1 cells. Treatment of BGJ398 did not affect the SKOV3ip1 cell viability in monolayer culture system, but, the cell viability of sphere-cultured SKOV3ip1 cells was markedly reduced by BGJ398. The phosphorylation of AKT and STAT3 was downregulated by BGJ398 in sphere-cultured SKOV3ip1 cells, but not in monolayer cultured-SKOV3ip1 cells. Moreover, combination treatment with BGJ398 and paclitaxel in sphere-cultured SKOV3ip1 showed synergistic inhibitory effect on cell viability. Collectively, our report reveals the BGJ398 is a potent antitumor agent against ovarian cancer and FGFR is a promising therapeutic target to anticancer therapy considering ovarian cancer metastatic microenvironment.

Kinetin Improves Barrier Function of the Skin by Modulating Keratinocyte Differentiation Markers.

BACKGROUND: Kinetin is a plant hormone that regulates growth and differentiation. Keratinocytes, the basic building blocks of the epidermis, function in maintaining the skin barrier. OBJECTIVE: We examined whether kinetin induces skin barrier functions in vitro and in vivo. METHODS: To evaluate the efficacy of kinetin at the cellular level, expression of keratinocyte differentiation markers was assessed. Moreover, we examined the clinical efficacy of kinetin by evaluating skin moisture, transepidermal water loss (TEWL), and skin surface roughness in patients who used kinetin-containing cream. We performed quantitative real-time polymerase chain reaction to measure the expression of keratinocyte differentiation markers in HaCaT cells following treatment. A clinical trial was performed to assess skin moisture, TEWL, and evenness of skin texture in subjects who used kinetin-containing cream for 4 weeks. RESULTS: Kinetin increased involucrin, and keratin 1 mRNA in HaCaT cells. Moreover, use of a kinetin-containing cream improved skin moisture and TEWL while decreasing roughness of skin texture. CONCLUSION: Kinetin induced the expression of keratinocyte differentiation markers, suggesting that it may affect differentiation to improve skin moisture content, TEWL, and other signs of skin aging. Therefore, kinetin is a potential new component for use in cosmetics as an anti-aging agent that improves the barrier function of skin.

Phytosphingosine-1-phosphate and epidermal growth factor synergistically restore extracellular matrix in human dermal fibroblasts in vitro and in vivo.

Phytosphingosine-1-phosphate (PhS1P), which is found in plants and fungi, is generated by the phosphorylation of phytosphingosine and is structurally similar to molecules that promote cellular growth and proliferation. The aim of this study was to ascertain whether PhS1P displays synergistic effects together with epidermal growth factor (EGF), which is also critical for activating proliferation, migration and survival pathways. We utilized cultured human dermal fibroblasts (HDFs) and a number of assays, including western blotting, cell migration assays, quantitative (real-time) PCR, and viability assays. We found that PhS1P promoted the activity of EGF in vitro. We then conducted a clinical trial in females over 35 years of age, with visible signs of skin aging. By evaluating skin hydration, dermal density and thickness, length of fine wrinkles, and skin elasticity, we verified the clinical efficacy of a combined treatment of PhS1P and EGF in vivo. On the whole, our data suggest that PhS1P displays a synergistic anti-aging effect together with EGF, both in vitro and in vivo.

Single Low-Dose Radiation Induced Regulation of Keratinocyte Differentiation in Calcium-Induced HaCaT Cells.

BACKGROUND: We are continually exposed to low-dose radiation (LDR) in the range 0.1 Gy from natural sources, medical devices, nuclear energy plants, and other industrial sources of ionizing radiation. There are three models for the biological mechanism of LDR: the linear no-threshold model, the hormetic model, and the threshold model. OBJECTIVE: We used keratinocytes as a model system to investigate the molecular genetic effects of LDR on epidermal cell differentiation. METHODS: To identify keratinocyte differentiation, we performed western blots using a specific antibody for involucrin, which is a precursor protein of the keratinocyte cornified envelope and a marker for keratinocyte terminal differentiation. We also performed quantitative polymerase chain reaction. We examined whether LDR induces changes in involucrin messenger RNA (mRNA) and protein levels in calcium-induced keratinocyte differentiation. RESULTS: Exposure of HaCaT cells to LDR (0.1 Gy) induced p21 expression. p21 is a key regulator that induces growth arrest and represses stemness, which accelerates keratinocyte differentiation. We correlated involucrin expression with keratinocyte differentiation, and examined the effects of LDR on involucrin levels and keratinocyte development. LDR significantly increased involucrin mRNA and protein levels during calcium-induced keratinocyte differentiation. CONCLUSION: These studies provide new evidence for the biological role of LDR, and identify the potential to utilize LDR to regulate or induce keratinocyte differentiation.

Apigenin inhibits UVA-induced cytotoxicity in vitro and prevents signs of skin aging in vivo.

Apigenin (4',5,7-trihydroxyflavone) is a flavone that has been reported to have anti-inflammatory, antioxidant and anti-carcinogenic properties. In this study, we investigated the protective effects of apigenin on skin and found that, in experiments using cells, apigenin restored the viability of normal human dermal fibroblasts (nHDFs), which had been decreased by exposure to ultraviolet (UV) radiation in the UVA range. Using a senescence-associated (SA)-ß-gal assay, we also demonstrate that apigenin protects against the UVA-induced senescence of nHDFs. Furthermore, we found that apigenin decreased the expression of the collagenase, matrix metalloproteinase (MMP)-1, in UVA-irradiated nHDFs. UVA, which has been previously identified as a photoaging-inducing factor, has been shown to induce MMP-1 expression. The elevated expression of MMP-1 impairs the collagen matrix, leading to the loss of elasticity and skin dryness. Therefore, we examined the clinical efficacy of apigenin on aged skin, using an apigenin­containing cream for clinical application. Specifically, we measured dermal density, skin elasticity and the length of fine wrinkles in subjects treated with apigenin cream or the control cream without apigenin. Additionally, we investigated the effects of the apigenin-containing cream on skin texture, moisture and transepidermal water loss (TEWL). From these experiments, we found that the apigenin­containing cream increased dermal density and elasticity, and reduced fine wrinkle length. It also improved skin evenness, moisture content and TEWL. These results clearly demonstrate the biological effects of apigenin, demonstrating both its cellular and clinical efficacy, and suggest that this compound holds promise as an anti-aging cosmetic ingredient.

Epigallocatechin Gallate-Mediated Alteration of the MicroRNA Expression Profile in 5α-Dihydrotestosterone-Treated Human Dermal Papilla Cells.

BACKGROUND: Dihydrotestosterone (DHT) induces androgenic alopecia by shortening the hair follicle growth phase, resulting in hair loss. We previously demonstrated how changes in the microRNA (miRNA) expression profile influenced DHT-mediated cell death, cell cycle arrest, cell viability, the generation of reactive oxygen species (ROS), and senescence. Protective effects against DHT have not, however, been elucidated at the genome level. OBJECTIVE: We showed that epigallocatechin gallate (EGCG), a major component of green tea, protects DHT-induced cell death by regulating the cellular miRNA expression profile. METHODS: We used a miRNA microarray to identify miRNA expression levels in human dermal papilla cells (DPCs). We investigated whether the miRNA expression influenced the protective effects of EGCG against DHT-induced cell death, growth arrest, intracellular ROS levels, and senescence. RESULTS: EGCG protected against the effects of DHT by altering the miRNA expression profile in human DPCs. In addition, EGCG attenuated DHT-mediated cell death and growth arrest and decreased intracellular ROS levels and senescence. A bioinformatics analysis elucidated the relationship between the altered miRNA expression and EGCG-mediated protective effects against DHT. CONCLUSION: Overall, our results suggest that EGCG ameliorates the negative effects of DHT by altering the miRNA expression profile in human DPCs.

Biological effects of rutin on skin aging.

Rutin, a quercetin glycoside is a member of the bioflavonoid family which is known to possess antioxidant properties. In the present study, we aimed to confirm the anti­aging effects of rutin on human dermal fibroblasts (HDFs) and human skin. We examined the effects of rutin using a cell viability assay, senescence-associated-ß-galactosidase assay, reverse transcription-quantitative polymerase chain reaction, and by measuring reactive oxygen species (ROS) scavenging activity in vitro. To examine the effects of rutin in vivo, rutin­containing cream was applied to human skin. A double-blind clinical study was conducted in 40 subjects aged between 30-50 years and divided into control and experimental groups. The test material was applied for 4 weeks. After 2 and 4 weeks, dermal density, skin elasticity, the length and area of crow's feet, and number of under-eye wrinkles following the application of either the control or the rutin-containing cream were analyzed. Rutin increased the mRNA expression of collagen, type I, alpha 1 (COL1A1) and decreased the mRNA expression of matrix metallopeptidase 1 (MMP1) in HDFs. We verified that ROS scavenging activity was stimulated by rutin in a dose­dependent manner and we identified that rutin exerted protective effects under conditions of oxidative stress. Furthermore, rutin increased skin elasticity and decreased the length, area and number of wrinkles. The consequences of human aging are primarily visible on the skin, such as increased wrinkling, sagging and decreased elasticity. Overall, this study demonstrated the biological effects of rutin on ROS-induced skin aging.

Intercellular and intracellular functions of ceramides and their metabolites in skin (Review).

The skin consists of the epidermis, dermis and subcutis. The epidermis is primarily comprised of keratinocytes and is separated into four layers according to the stage of differentiation of the keratinocytes. Corneocytes are terminally differentiated keratinocytes that closely interact with other corneocytes through corneodesmosomes, and synthesize lamellar bodies and the intercellular multilamellar barrier, which protects the body from the external environment. As ceramides are the principal components of lamellar bodies and the multilamellar barrier, it is important to understand the biosynthesis of ceramides and their functions in skin. Ceramides are synthesized by amide bond­mediated interactions between sphingoid bases, long­chain amino alcohols [long-chain base] and fatty acids through a de novo pathway, a sphingomyelin (SM) hydrolysis pathway and a catabolic pathway. The majority of ceramides produced by the de novo pathway form the epidermal barrier. Ceramides used as signaling molecules are synthesized by the SM and catabolic pathways. Synthesized ceramides are released from corneocytes and form the multilamellar barrier. Additionally, ceramides and their metabolites regulate the apoptosis, proliferation and differentiation of skin cells as well as the formation of the skin barrier. Thus, the study of ceramides and their metabolites is crucial to understanding the function and regulation of the skin barrier.

Topical application of a cleanser containing extracts of Diospyros kaki folium, Polygonum cuspidatum and Castanea crenata var. dulcis reduces skin oil content and pore size in human skin.

The effects of skin pores on skin topographic features can be reduced by decreasing excessive production and accumulation of sebum and elimination of comedones. Therefore, a cosmetic cleanser that regulates sebum homeostasis is required. In the present study, the effects of a cosmetic cleanser that contained Diospyros kaki folium, Polygonum cuspidatum and Castanea crenata var. dulcis (DPC) was examined on the removal of sebum and on skin pore size. Healthy volunteers (n=23) aged 20-50 years were asked to apply the test materials to the face. Skin oil content, pore size, pore number and extracted sebum surface area were measured using various measurement methods. All the measurements were performed at pre- and post-application of the test materials. When the cosmetic cleanser containing DPC was applied to the skin, the oil content decreased by 77.3%, from 6.19 to 1.40. The number of skin pores decreased by 24.83%, from 125.39 to 94.23. Skin pore size decreased from 0.07 to 0.02 µm3 (71.43% decrease). The amount of extracted sebum increased by 335% when the DPC cleanser was used. Compared to the control cleanser, skin oil content was significantly decreased when the cleanser that contained DPC was used. The cleanser containing DPC also decreased pore size and number. Finally, the DPC cleanser easily removed solidified sebum from the skin.

Implication of microRNA regulation in para-phenylenediamine-induced cell death and senescence in normal human hair dermal papilla cells.

Para-phenylenediamine (PPD) is a major component of hair coloring and black henna products. Although it has been largely demonstrated that PPD induces allergic reactions and increases the risk of tumors in the kidney, liver, thyroid gland and urinary bladder, the effect on dermal papilla cells remains to be elucidated. Therefore, the current study evaluated the effects of PPD on growth, cell death and senescence using cell-based assays and microRNA (miRNA) microarray in normal human hair dermal papilla cells (nHHDPCs). Cell viability and cell cycle analyses demonstrated that PPD exhibited a significant cytotoxic effect on nHHDPCs through inducing cell death and G2 phase cell cycle arrest in a dose-dependent manner. It was additionally observed that treatment of nHHDPCs with PPD induced cellular senescence by promoting cellular oxidative stress. In addition, the results of the current study indicated that these PPD-mediated effects were involved in the alteration of miRNA expression profiles. Treatment of nHHDPCs with PPD altered the expression levels of 74 miRNAs by ≥ 2-fold (16 upregulated and 58 downregulated miRNAs). Further bioinformatics analysis determined that these identified miRNA target genes were likely to be involved in cell growth, cell cycle arrest, cell death, senescence and the induction of oxidative stress. In conclusion, the observations of the current study suggested that PPD was able to induce several cytotoxic effects through alteration of miRNA expression levels in nHHDPCs.

Analysis of the microRNA expression profile of normal human dermal papilla cells treated with 5α-dihydrotestosterone.

Clinical evidence has demonstrated that the accumulation of 5α-dihydrotestosterone (DHT) in dermal papilla cells (DPCs) is implicated in androgenetic alopecia. Whether this accumulation in DHT may have direct cellular effects leading to androgenetic alopecia remains to be elucidated. The present study aimed to determine whether DHT affects cell growth, cell cycle arrest, cell death, senescence and the induction of reactive oxygen species (ROS), and whether these effects are mediated by microRNA (miRNA)-dependent mechanisms. The cell viability and cell cycle were determined, levels of ROS were examined and senescence-associated ß-galactosidase assays were performed in normal human DPCs (nHDPCs). Furthermore, miRNA expression profiling was performed using an miRNA microarray to determine whether changes in the expression levels of miRNA were associated with the cellular effects of DHT. The results revealed that DHT decreased cell growth by inducing cell death and G2 cell cycle arrest, and by increasing the production of ROS and senescence in the nHDPCs. In addition, 55 miRNAs were upregulated and 6 miRNAs were downregulated in the DHT-treated nHDPCs. Bioinformatic analysis demonstrated that the putative target genes of these upregulated and downregulated miRNAs were involved in cell growth, cell cycle arrest, cell death, senescence and the production of ROS. Specifically, the target genes of five highly upregulated and downregulated miRNAs were identified and were associated with the aforementioned effects of DHT. These results demonstrated that the expression of miRNA was altered in the DHT-treated nHDPCs and suggest the potential mechanisms of DHT-induced cell growth repression, cell cycle arrest, cell death, senescence and induction of ROS.

Low-dose γ-irradiation induces dual radio-adaptive responses depending on the post-irradiation time by altering microRNA expression profiles in normal human dermal fibroblasts.

Exposure to high-dose ionizing radiation, including γ-radiation, induces severe skin disorders. However, the biological consequences and molecular mechanisms responsible for the response of human skin to low-dose γ-radiation (LDR) are largely unknown. In the present study, we demonstrate that LDR (0.1 Gy) induces distinct cellular responses in normal human dermal fibroblasts (NHDFs) depending on the post-irradiation time point. A MTT-based cell viability assay and propidium iodide staining-based cell cycle assay revealed that the viability and proportion of the cells in the G2/M phase were differed at 6 and 24 h post-irradiation. Reverse transcription quantitative PCR (RT-qPCR) revealed that LDR significantly upregulated the mRNA expression of collagen type I alpha 1 (COL1A1), but downregulated the mRNA expression of matrix metalloproteinase 1 (MMP1) at 24 h post-irradiation. MicroRNA (miRNA) microarray analysis further demonstrated that LDR induced changes in the expression profiles of specific miRNAs and that some of the deregulated miRNAs were specific to either the early or late radio-adaptive response. Our results suggest that LDR generates dual radio-adaptive responses depending on the post-irradiation time by altering specific miRNA expression profiles in NHDFs.

Arctiin blocks hydrogen peroxide-induced senescence and cell death though microRNA expression changes in human dermal papilla cells.

BACKGROUND: Accumulating evidence indicates that reactive oxygen species (ROS) are an important etiological factor for the induction of dermal papilla cell senescence and hair loss, which is also known alopecia. Arctiin is an active lignin isolated from Arctium lappa and has anti-inflammation, anti-microbial, and anti-carcinogenic effects. In the present study, we found that arctiin exerts anti-oxidative effects on human hair dermal papilla cells (HHDPCs). RESULTS: To better understand the mechanism, we analyzed the level of hydrogen peroxide (H2O2)-induced cytotoxicity, cell death, ROS production and senescence after arctiin pretreatment of HHDPCs. The results showed that arctiin pretreatment significantly inhibited the H2O2-induced reduction in cell viability. Moreover, H2O2-induced sub-G1 phase accumulation and G2 cell cycle arrest were also downregulated by arctiin pretreatment. Interestingly, the increase in intracellular ROS mediated by H2O2 was drastically decreased in HHDPCs cultured in the presence of arctiin. This effect was confirmed by senescence associated-beta galactosidase (SA-ß-gal) assay results; we found that arctiin pretreatment impaired H2O2-induced senescence in HHDPCs. Using microRNA (miRNA) microarray and bioinformatic analysis, we showed that this anti-oxidative effect of arctiin in HHDPCs was related with mitogen-activated protein kinase (MAPK) and Wnt signaling pathways. CONCLUSIONS: Taken together, our data suggest that arctiin has a protective effect on ROS-induced cell dysfunction in HHDPCs and may therefore be useful for alopecia prevention and treatment strategies.

Altered microRNA expression profiles are involved in resistance to low-dose ionizing radiation in the absence of BMI1 in human dermal fibroblasts.

The polycomb group RING finger protein, B-cell­specific moloney murine leukemia virus integration site 1 (BMI1), has emerged as a key regulator of cell proliferation, cell cycle, cell immortalization, chemoresistance and radioresistance. Although the radioresistant effect of BMI1 has been thoroughly investigated, the effectiveness of this factor on low-dose radiation (LDR) resistance has not been explored. Here, we demonstrate that BMI1 is not critical for altering cell viability or cell growth in response to LDR, but BMI1 changes cellular gene expression profiles in response to LDR. Normal human dermal fibroblasts (NHDFs) stably expressing BMI1 short hairpin RNA (shRNA) did not exhibit changes in cell viability or cell cycle distribution assays following exposure to 0.1 Gy of γ-radiation. However, microRNA (miRNA) microarrays revealed that a lack of BMI1 leads to changes in miRNA expression in response to LDR. Bioinformatics analyses demonstrated that predicted target genes of the altered miRNAs are functionally involved in both negative and positive regulation of cell growth, cell proliferation, cell cycle and apoptosis. Therefore, these results indicate that low radiosensitivity even in the absence of the radioresistant factor BMI1 is related with the altered miRNA expression profiles in NHDF.