Dan Jian

Diethylstilbestrol enhances melanogenesis via cAMP-PKA-mediating up-regulation of tyrosinase and MITF in mouse B16 melanoma cells.

BACKGROUND It is well known that melanin synthesis in melanoma cells is controlled by melanogenic enzymes, which regulate the cAMP-PKA signaling pathway. Estrogen was previously reported to upregulate melanogenesis that is associated with human skin pigmentation. OBJECTIVE To investigate the influence and mechanism of diethylstilbestrol (DES) on melanogenesis in mouse B16 melanoma cells. METHODS The effects of diethylstilbestrol on cell viability, melanin content, tyrosinase activity, cAMP level, expression of the tyrosinase family and microphthalmia related transcription factor (MITF) were measured in B16 melanoma. Estrogen receptor (ER) expression were detected in B16 melanoma and A375 melanoma. Diethylstilbestrol-induced melanin synthesis were evaluated in the presence and absence of H89 (a PKA-specific inhibitor) and ICI182, 780 (a pure ER antagonist). Tyrosinase activity, the mRNA levels of tyrosinase and MITF were evaluated in the presence and absence of H89. RESULTS In B16 cells, diethylstilbestrol increased cell proliferation, melanin synthesis, tyrosinase activity and expression of the tyrosinase family and MITF. ER expression have not difference in human and mouse melanoma. When ER were inhibited by ICI182, 780, DES-induced melanogenesis was significantly reduced. Diethylstilbestrol enhanced the level of cAMP. The upregulation of melanin content and tyrosinase activity stimulated by diethylstilbestrol was significantly attenuated in the presence of H89. Further, diethylstilbestrol-induced upregulation of tyrosinase and MITF were significantly attenuated when the PKA pathway was blocked. CONCLUSIONS Diethylstilbestrol can enhance melanin synthesis in melanoma cells. This effect is associated with activation of the cAMP-PKA pathway and upregulation of expression and activity of the melanogenesis-related enzyme tyrosinase and MITF.

Adverse effects of propranolol treatment for infantile hemangiomas in China

Objectives: The β-blocker propranolol was discovered to be highly effective for the treatment of infantile hemangiomas (IHs), since 2008. Although some side effects have been reported earlier, no serious side effects of its use have been reported so far in Asia, especially in China. To determine the safety of this therapy, the side effects were analyzed in 97 infants who used propranolol (2 mg kg−1·d−1) against hemangioma from 2010 to 2011. Materials and methods: Routine blood and urine tests, hepatic and renal function tests, myocardial enzyme, electrolytes and blood sugar levels at baseline were performed. Electrocardiogram monitoring was performed 48 h after administration of the first dose (2 mg kg−1·d−1). Every patient (n = 97) was required to report to the hospital once a month. Results: The following adverse effects were observed: bronchial hyperactivity (n = 5), cyanosis and cold extremities (n = 1), agranulocytosis (n = 1), and low body temperature (n = 1). These side effects were reported for the first time in Asia. Conclusions: Although propranolol is effective against IHs, its potential side effects should be considered and appropriate monitoring performed. Further studies need to be conducted to determine the optimal dose and duration of propranolol treatment for large and complex hemangiomas.

G protein-coupled estrogen receptor enhances melanogenesis via cAMP-protein kinase (PKA) by upregulating microphthalmia-related transcription factor-tyrosinase in melanoma.

OBJECTIVE This study investigated the role and mechanism of action of G protein-coupled estrogen receptor (GPER) in melanogenesis. METHODS GPER expression was detected in the A375 human melanoma cell line and B16 mouse melanoma cell line. Cell proliferation, melanin content, tyrosinase (TYR) activity, cyclic adenosine monophosphate (cAMP) level, and TYR and microphthalmia-related transcription factor (MITF) expression were measured. GPER activation was altered by agonist and antagonist treatment and its expression was downregulated by gene silencing. Estradiol-induced melanin synthesis and the activation of related signaling pathways were suppressed by inhibiting GPER via antagonist treatment. The relationship between GPER and TYR was evaluated in clinical chloasma samples by immunohistochemistry. RESULTS Upregulation of GPER in A375 cells promoted melanogenesis, favored as indicated by increases in TYR and MITF expression and TYR activity. GPER activated melanin production via the cAMP-protein kinase (PK) A pathway, suggesting that GPER plays an important role in estrogen-induced melanin synthesis. The effect of GPER activation on cAMP-MITF-TYR signaling was also demonstrated in B16 cells. A significant association was observed between GPER and TYR expression in chloasma skin lesions relative to normal skin. CONCLUSION GPER enhances melanin synthesis via cAMP-PKA-MITF-TYR signaling and modulates the effects of estrogen in melanogenesis. GPER is therefore a potential drug target for chloasma treatment.

The association between treatment reactions and treatment efficiency of Hemoporfin-photodynamic therapy on port wine stains: A prospective double blind randomized controlled trial

BACKGROUND Research has focused on treatment efficiency and/or treatment reactions of photodynamic therapy (PDT) on port-wine stain (PWS). But few studies reported the association between them. Hence, here we investigated the association between the treatment efficiency and treatment reactions after Hemoporfin (HMME) mediated photodynamic therapy (PDT) on PWS through a prospective study. METHODS Patients (n=50) with PWS were randomly assigned to the HMME group or the placebo group. Three quit after the first treatment, and forty-seven received two sessions of treatment at an 8-week interval. They were given the treatment at day 1 and evaluations were performed at day 1, day 4 and week 8 in each session. HMME group was treated with HMME while the placebo group was given normal saline instead in the first session, double-blindly. While in the second session, both groups received HMME-PDT treatment. RESULTS After a single treatment, swelling was more severe in younger patients (p<0.05) and the lesion far from centro-facial showed more severe pruritus and scab. Compared with a single treatment, burning sensation had a higher occurrence rate, while burning sensation and scab were less severe in the second treatment. Importantly, severity of scab and pain (5min after irradiation) were found possibly correlated with the treatment efficiency. CONCLUSION HMME-PDT on PWS induces several treatment reactions, including pruritus, burning sensation, pain, swelling, blisters and scab. Two sessions of treatments do not have any accumulation effects on treatment reactions. And there might be a positive correlation between treatment efficiency and the severity of scab or pain (at early stage of the therapy), which might help in regulating treatment modalities.

Rebounding triad (severe itching, dryness and burning) after facial corticosteroid discontinuation defines a specific class of corticosteroid-dependent dermatitis

In patients with dermatitis, the sudden discontinuation of topical corticosteroid (TC) use after long‐term treatment could cause flaring symptoms (named “rebounding responses”). Diagnostic criteria for facial corticosteroid‐dependent dermatitis (FCDD) are vague and uncertain. We aim to define a category of patients with clinical rebounding triad including severe itching, dryness and burning. Patients with FCDD (n = 268) were evaluated to determine distinctive rebounding triad manifestations after TC cessation. Data on history of facial TC use and rebounding presentations were collected. A group of chronic dermatitis patients (n = 83) with rebounding triad after TC discontinuation were enrolled and added to patients with FCDD presenting triad symptoms. Patients without triad were compared with triad‐positive patients. Eighty‐five patients who displayed triad manifestations after TC cessation showed longer (93.1 ± 53.6 vs 9.6 ± 5.5 weeks, P < 0.001) and more frequent (7.7 ± 4.5 vs 2.3 ± 1.6 times/week, P < 0.001) use of TC. Similar results were observed after adding 83 dermatitis patients who experienced triad after TC cessation. Multivariate analysis showed that mean duration of TC use (odds ratio [OR] = 1.83, 95% confidence interval (95% CI) = 1.042–3.218, P = 0.035) and mean frequency of TC use (OR = 2.802, 95% CI = 1.135–6.918, P = 0.025) were independent predictors of rebounding triad after TC cessation. Duration and frequency of TC use were the main factors predicting rebounding triad.

A novel mutation for disseminated superficial actinic porokeratosis in the MVK gene

M. TOHYAMA K. HASH IMOTO Y . KANO T. SH IOHARA K . I TO H. FU J I TA M. A IHARA H. ASADA Department of Dermatology, Nara Medical University School of Medicine, 840 Shijocho, Kashihara, Nara 634-8522, Japan Department of Dermatology, Showa University School of Medicine, Tokyo, Japan Department of Dermatology, Ehime University Graduate School of Medicine, Matsuyama, Japan Department of Dermatology, Kyorin University School of Medicine, Tokyo, Japan Department of Environmental ImmunoDermatology, Yokohama City University Graduate School of Medicine, Yokohama, Japan Correspondence: Hideo Asada. E-mail: asadah@naramed-u.ac.jp

Microrna-217 modulates human skin fibroblast senescence by directly targeting DNA methyltransferase 1

DNA methyltransferase 1 (DNMT1) is a major epigenetic regulator associated with many biological processes. However, the roles and mechanisms of DNMT1 in skin aging are incompletely understood. Here we explored the role of DNMT1 in human skin fibroblasts senescence and its related regulatory mechanisms. DNMT1 expression decreased in passage-aged fibroblasts and DNMT1 silencing in young fibroblasts induced the senescence phenotype. MiR-217 is predicted to target DNMT1 mRNA and miR-217 expression increased in passage-aged fibroblasts. MiR-217 directly targeted the 3′-untranslated region (3′-UTR) of DNMT1 in HEK 293T cells and inhibited DNMT1 expression in fibroblasts. MiR-217 overexpression induced a senescence phenotype in young fibroblasts, and miR-217 downregulation in old HSFs partially reversed the senescence phenotype. However, these effects could be significantly rescued by regulating DNMT1 expression in fibroblasts. After regulating miR-217 levels, we analyzed changes in the promoter methylation levels of 24 senescent-associated genes, finding that 6 genes were significantly altered, and verified p16 and phosphorylated retinoblastoma (pRb) protein levels. Finally, an inverse correlation between DNMT1 and miR-217 expression was observed in skin tissues and different-aged fibroblasts. Together, these findings revealed that miR-217 promotes fibroblasts senescence by suppressing DNMT1-mediated methylation of p16 and pRb by targeting the DNMT1 3′-UTR.

Asymmetrical dimethylarginine promotes the senescence of human skin fibroblasts via the activation of a reactive oxygen species-p38 MAPK-microRNA-138 pathway

Asymmetrical dimethylarginine promotes the senescence of human skin fibroblasts via the activation of a reactive oxygen species-p38 MAPK-microRNA-138 pathway dose-dependently increased with ADMA treatment in HSFs (Fig. 1D). Our results indicated that exogenous ADMA might induce a senescent phenotype in HSFs. As ADMA is known to accelerate EC senescence by increasing oxidative stress, and because p38 MAPK can be activated by oxidative stressors such as ROS [2], the contribution of ROS-p38 MAPK activation to ADMA-induced senescence was evaluated. Senescence markers were evaluated in HSFs treated with NAC

Fluorofenidone inhibits UV-A induced senescence in human dermal fibroblasts via the mammalian target of rapamycin-dependent SIRT1 pathway

The aim of this study was to investigate the protective effect of fluorofenidone (5‐methyl‐1‐[3‐fluorophenyl]‐2‐[1H]‐pyridone, AKF‐PD) on ultraviolet (UV)‐A‐induced senescence in human dermal fibroblasts (HDF) and examine the mechanisms involved. HDF were treated with AKF‐PD. Senescence‐associated (SA)‐β‐galactosidase level, cell viability and expression of p16 were evaluated. In addition, UV‐A‐irradiated HDF were treated with AKF‐PD, rapamycin and MHY1485; SA‐β‐galactosidase staining, 3‐(4 5‐dimethylthiazol‐2‐yl)‐2 5‐diphenyltetrazolium bromide assay and western blot for SIRT1 were performed; and phosphorylated mammalian target of rapamycin (p‐mTOR) expression and reactive oxygen species (ROS) levels were measured. Intracellular ROS was detected by the 2′,7′‐dichlorofluroescein diacetate probe. Our results showed that AKF‐PD substantially attenuated the changes of p16 expression, SA‐β‐galactosidase staining and cellular proliferation induced by UV‐A irradiation in HDF. AKF‐PD rescued the increased mTOR phosphorylation and reduced SIRT1 expression induced by UV‐A irradiation in HDF. AKF‐PD and rapamycin together had a synergistic effect on p‐mTOR reduction and SIRT1 increase. mTOR activator MHY1485 partly blocked the above effects. Moreover, intracellular ROS level induced by UV‐A irradiation could partly decrease by AKF‐PD, and MHY1485 could reduce this effect. Our results indicated that AKF‐PD could alleviate HDF senescence induced by UV‐A‐irradiation by inhibiting the p‐mTOR and increasing SIRT1. Moreover, AKF‐PD may be a potential treatment material for skin.

An observational descriptive survey of rosacea in the Chinese population: clinical features based on the affected locations

Background There is currently no study that has evaluated the differences in epidemiological and clinical characteristics among rosacea patients according to different facial sites. Methods Clinical and demographic data were obtained from 586 rosacea patients. The patients were divided into four groups based on the main sites involved with the rosacea lesions (full-face, cheeks, nose, or perioral involvement). Clinical signs were measured through self-reported, dermatologist-evaluated grading of symptoms, and physiological indicators of epidermal barrier function. Results There were 471 (80.4%), 49 (8.4%), 52 (8.9%), and 14 (2.4%) cases in the full-face, cheek, nasal and perioral groups, respectively. Compared with the healthy control, the full-face group had lower water content and higher transepidermal water loss (TEWL) in the cheeks, and chin; the perioral group had lower water content and higher TEWL in the chin; while the nasal group had the normal water content and TEWL. Compared with the full-face group, the nasal group had more severe phymatous changes, less severe self-reported and dermatologist-evaluated grading of symptoms. All the patients in the perioral or the nasal group had their first rosacea lesions start and remain at the chin or on the nose. In the full-face group, 55.8% of patients had their lesions start with the full face, 40.1% on the cheek, and the rest (4.1%) on the nose. Conclusion Significant differences in clinical features were observed among rosacea patients with lesions at four different sites. The lesion localization of each group was relatively stable and barely transferred to other locations.