RESUMEN

Objective:To explore expression patterns of transcription factor TFAP2B in epidermal melanocytes of healthy individuals and vitiligo patients.Methods:Lesional tissues were collected from 5 patients confirmedly diagnosed with progressive vitiligo at the Department of Dermatology, Xijing Hospital, Air Force Medical University from January 2020 to December 2022. At the same time, some discarded normal skin tissues were obtained from 5 gender- and age-matched healthy individuals after plastic surgeries. The immortalized healthy human epidermal melanocyte cell line PIG1, the vitiligo epidermal melanocyte cell line PIG3V, and primary human epidermal melanocytes, which were isolated from the discarded foreskin tissues of 3 healthy males after urological surgeries in Xijing Hospital, were cultured in vitro. Tissue immunofluorescence assay was performed to determine the expression and localization of TFAP2B and dopachrome tautomerase (DCT) in healthy skin tissues and vitiligo lesions, and cell immunofluorescence assay and Western blot analysis were conducted to determine the TFAP2B expression in human epidermal melanocytes. Comparisons between two groups were performed using t test, and correlation analysis was performed using Pearson correlation coefficients. Results:Tissue immunofluorescence assay showed that TFAP2B was specifically expressed in human epidermal melanocytes and localized in the nuclei. Western blot analysis showed that TFAP2B was strongly expressed in the human epidermal melanocyte cell line PIG1 and primary melanocytes, with the relative expression levels being 0.45 ± 0.05 and 0.36 ± 0.04, respectively. Tissue immunofluorescence analysis showed that the fluorescence intensity of TFAP2B (623 917.5 ± 88 784.0) was significantly and positively correlated with that of DCT (2 232 655.3 ± 588 810.4; r = 0.91, P < 0.001) in human epidermal tissues from 5 healthy controls and 5 vitiligo patients. In addition, the relative fluorescence intensity of TFAP2B in epidermal melanocytes was significantly lower in the vitiligo lesions (0.12 ± 0.05) than in the healthy skin tissues (1, t = 19.35, P < 0.001). Western blot analysis showed that the relative expression level of TFAP2B was also significantly lower in the PIG3V cells (0.62 ± 0.09) than in the PIG1 cells (1, t = 5.92, P < 0.027) . Conclusions:TFAP2B was specifically and highly expressed in human epidermal melanocytes, and its expression level was significantly and positively correlated with that of the melanocyte marker DCT. Additionally, TFAP2B was obviously lowly expressed in the epidermal melanocytes of patients with vitiligo.

RESUMEN

The etiology and pathogenesis of vitiligo have not yet been clear, and animal models are important tools for vitiligo research. In addition to traditional mouse models of vitiligo, many new models have been gradually established with the deepening of research, such as mouse models expressing epidermal melanocytes and melanocyte-reactive T cells, K14-SCF/h3TA2/HLA-A2 triple-transgenic mouse (Vitesse mice) models, autoimmune-induced mouse models, chemical reagent-induced mouse models, etc. Manifestations of these models are highly similar to human vitiligo, their reproducibility and stability have been improved to different extents, and they have already become good models for exploring the pathogenesis of and therapeutic targets for vitiligo, as well as for evaluating therapeutic efficacy. This review summarizes current research progress and existing problems in mouse models of vitiligo-like depigmentation.

RESUMEN

Objective:To analyze clinical and histopathological characteristics of infantile congenital melanocytic nevi (ICMN) .Methods:Clinical and pathological data were collected from 126 infants with confirmedly diagnosed congenital melanocytic nevi in Department of Dermatology, Xijing Hospital from January 2015 to January 2020, and were retrospectively analyzed. Chi-square test was used for comparisons of enumeration data.Results:Among the 126 patients with ICMN, 68 were males and 58 were females; 109 (86.5%) presented with skin lesions at birth; 73 (57.9%) were 2 - 3 years old at the first clinic visit. The skin lesions occurred on the head and face (76 cases, 60.3%) , trunk (24 cases, 19.1%) or extremities (26 cases, 20.6%) . There were 36 (28.6%) patients with small congenital nevi, 68 (54.0%) with M1-type medium-sized nevi, 13 (10.3%) with M2-type medium-sized nevi and 9 (7.1%) with giant nevi. Of 126 cases of ICMN, 121 (96.0%) had solitary lesions, 5 (4.0%) had multiple lesions, 44 (34.9%) had nevi with coarse hairs, 15 (11.9%) had nevi complicated by papules or hyperplastic nodules, and 6 (4.8%) had satellite lesions. Pathological subtypes included compound nevus (120 cases, 95.2%) , intradermal nevus (4 cases, 3.2%) , and junctional nevus (2 cases, 1.6%) . Under the microscope, the depth of the skin lesions was < 1 mm in 38 (30.1%) cases, 1 - 2 mm in 61 (48.4%) and > 2 mm in 25 (19.8%) , and 45 (35.7%) cases showed nevus cells infiltrating the subcutaneous fat layer or deeper tissues. Among the 126 ICMN lesions, common pathological features included nevus tissue maturation (100%, 2 cases of junctional nevi were excluded) , pigment granules in the stratum corneum (53 cases, 42.1%) , disordered/asymmetric distribution of nevus cells (80 cases, 63.5%) , scattered epidermal nevus cells (91 cases, 72.2%) , pagetoid spread of epidermal nevus cells (67 cases, 53.2%) , melanophages in the dermis (71 cases, 56.4%) , and nevus cells distributed along hair follicles/sebaceous glands (82 cases, 65.1%) . Special pathological features included nevus cells embedded in the vascular/lymphatic vessels (42 cases, 33.3%) , nevus cell lysis (45 cases, 35.7%) , fibromatous changes (25 cases, 19.8%) , involvement of the arrector pilli muscles (31 cases, 24.6%) , and mast cell infiltration (30 cases, 23.8%) . Pathological patterns of ICMN with different clinical features: the incidences of infiltration depth > 2 mm, pigment granules and columnar pigment granules in the stratum corneum were significantly higher in the giant nevi than in the small and medium-sized nevi ( χ2 = 7.93, 10.76, 5.89 respectively, all P < 0.05) ; the incidences of infiltration depth > 2 mm, epidermal spongiosis with scattered nevus cells, nevus cell nests distributed along the hair follicles/sebaceous glands, fibromatous changes and mast cell infiltration were significantly higher in the skin lesions with coarse hairs than in those without ( χ2 = 28.29, 8.11, 6.22, 7.92, 8.19 respectively, all P < 0.01) ; the incidences of pagetoid spread of epidermal nevus cells and atypical nevus cells were significantly higher in the skin lesions with papules/hyperplastic nodules than in those without papules/hyperplastic nodules ( χ2 = 4.92, 6.30 respectively, both P < 0.05) . Conclusions:The clinical and histopathological characteristics of ICMN are unique, and atypical nevus cells are common in ICMN. The diagnosis and treatment of ICMN need to be based on the combination of clinical and pathological characteristics.

RESUMEN

At present,specific targeted treatment of vitiligo is still lacking,and there are many limitations of current therapies,such as slow repigmentation process,long duration of treatment and frequent recurrence.As a therapeutic strategy for rapidly improving the appearance of patients,camouflage therapy has a unique advantage in the treatment of various skin diseases.Several studies in China and other countries have shown that the correct use of cosmetic camouflage can effectively improve the appearance and quality of life of patients with vitiligo.This review summarizes the knowledge about various camouflage therapies and related clinical researches on the relationship between camouflage therapies and quality of life of patients with vitiligo,and elaborates application prospects of camouflage therapies in the treatment of vitiligo.

RESUMEN

The design and development of novel dye sensitizers are effective method to improve the performance of dye-sensitized solar cells (DSSCs) because dye sensitizers have significant influence on photo-to-current conversion efficiency. In the procedure of dye sensitizer design, it is very important to understand how to tune their electronic structures and related properties through the substitution of electronic donors, acceptors, and conjugated bridges in dye sensitizers. Here, the electronic structures and excited-state properties of organic JK dye sensitizers are calculated by using density functional theory (DFT) and time dependent DFT methods. Based upon the calculated results, we investigated the role of different electronic donors, acceptors, and π-conjugated bridges in the modification of electronic structures, absorption properties, as well as the free energy variations for electron injection and dye regeneration. In terms of the analysis of transition configurations and molecular orbitals, the effective chromophores which are favorable for electron injection in DSSCs are addressed. Meanwhile, considering the absorption spectra and free energy variation, the promising electronic donors, π-conjugated bridges, and acceptors are presented to design dye sensitizers.

RESUMEN

Objective To explore the effects of NF-E2-related factor 2 (Nrf2) overexpression on mitochondrial biosynthesis and function in melanocytes.Methods An immortalized human vitiligo melanocyte cell line PIG3V was used in this study.An overexpression plasmid Nrf2-pEX-1 containing the full-length Nrf2 gene was constructed.PIG3V cells were divided into 3 groups:blank group receiving no treatment,control group transfected with the pEX-1 plasmid,overexpression group transfected with the Nrf2-pEX-1 plasmid.After transfection,real-time quantitative reverse transcription-PCR (RT-PCR) and Western blot were performed to determine the mRNA and protein levels of mitochondrial biosynthesis-related factors (including Nrf2,nuclear respiratory factor 1 (NRF1) and mitochondrial transcription factor A (TFAM)) respectively;RT-PCR was also conducted to measure the copy number of mitochondrial DNA (mtDNA),and flow cytometry to estimate mitochondial membrane potential (MMP);luciferase reporter system was used to estimate the intracellular adenosine triphosphate (ATP) level.Statistical analysis was carried out by using a two-sample t-test.Results After transfection,a significant increase was observed in the mRNA expression levels of Nrf2 and NRF1 at 24 hours (both P ＜ 0.001) and in those of Nrf2 and TFAM at 48 hours (both P ＜ 0.05),but no significant change was noted in the mRNA expression level of TFAM at 24 hours (P ＞ 0.05) or in that of NRF1 at 48 hours (P ＞0.05) in the overexpression group compared with the control group.In the case of Nrf2,NRF1 and TFAM protein levels,the overexpression group showed significant increases compared with the control group at 48 hours after transfection (all P ＜ 0.05),while no significant difference was noted between the two groups at 24 hours.Compared with the control group,MMP in the overexpression group increased by 2.313％ at 24 hours (t =5.546,P =0.005) and by 14.872％ at 48 hours (t =8.537,P =0.001) after transfection.Both the relative copy number of mtDNA and ATP level were similar between the overexpression group and control group at 24 hours after transfection (both P ＞ 0.05),but significantly higher in the overexpression group than in the control group at 48 hours (t =5.760,P =0.005;t =22.040,P =0.008).Conclusion Up-regulation of Nrf2 pathway can improve mitochondrial function and biosynthesis in PIG3V cells likely by promoting the expressions of mitochondrial biosynthesis-related genes and proteins.

RESUMEN

The electronic structures and excitation properties of dye sensitizers determine the photon-to-current conversion efficiency of dye sensitized solar cells (DSSCs). In order to understand the different performance of porphyrin dye sensitizers YD2 and YD2-o-C8 in DSSC, their geometries and electronic structures have been studied using density functional theory (DFT), and the electronic absorption properties have been investigated via time-dependent DFT (TDDFT) with polarizable continuum model for solvent effects. The geometrical parameters indicate that YD2 and YD2-o-C8 have similar conjugate length and charge transfer (CT) distance. According to the experimental spectra, the HSE06 functional in TDDFT is the most suitable functional for describing the Q and B absorption bands of porphyrins. The transition configurations and molecular orbital analysis suggest that the diarylamino groups are major chromophores for effective CT excitations (ECTE), and therefore act as electron donor in photon-induced electron injection in DSSCs. The analysis of excited states properties and the free energy changes for electron injection support that the better performance of YD2-o-C8 in DSSCs result from the more excited states with ECTE character and the larger absolute value of free energy change for electron injection.

Asunto(s)

RESUMEN

To understand the role of the conjugate bridge in modifying the properties of organic dye sensitizers in solar cells, the computations of the geometries and electronic structures for 10 kinds of tetrahydroquinoline dyes were performed using density functional theory (DFT), and the electronic absorption and fluorescence properties were investigated via time dependent DFT. The population analysis, molecular orbital energies, radiative lifetimes, exciton binding energies (EBE), and light harvesting efficiencies (LHE), as well as the free energy changes of electron injection ( ) and dye regeneration ( ) were also addressed. The correlation of charge populations and experimental open-circuit voltage (Voc) indicates that more charges populated in acceptor groups correspond to larger Voc. The elongating of conjugate bridge by thiophene units generates the larger oscillator strength, higher LHE, larger absolute value of , and longer relative radiative lifetime, but it induces the decreasing of EBE and . So the extending of conjugate bridge with thiopene units in organic dye is an effective way to increase the harvest of solar light, and it is also favorable for electron injection due to their larger . While the inversely correlated relationship between EBE and LHE implies that the dyes with lower EBE produce more efficient light harvesting.

RESUMEN

The computations of the geometries, electronic structures, dipole moments and polarizabilities for indoline and triphenylamine (TPA) based dye sensitizers, including D102, D131, D149, D205, TPAR1, TPAR2, TPAR4, and TPAR5, were performed using density functional theory, and the electronic absorption properties were investigated via time-dependent density functional theory with polarizable continuum model for solvent effects. The population analysis indicates that the donating electron capability of TPA is better than that of indoline group. The reduction driving forces for the oxidized D131 and TPAR1 are slightly larger than that of other dyes because of their lower highest occupied molecular orbital level. The absorption properties and molecular orbital analysis suggest that the TPA and 4-(2,2diphenylethenyl)phenyl substituent indoline groups are effective chromophores in intramolecular charge transfer (IMCT), and they play an important role in sensitization of dye-sensitized solar cells (DSCs). The better performance of D205 in DSCs results from more IMCT excited states with larger oscillator strength and higher light harvesting efficiency. While for TPA dyes, the longer conjugate bridges generate the larger oscillator strength and light harvesting efficiency, and the TPAR1 and TPAR4 have larger free energy change for electron injection and dye regeneration.

RESUMEN

Objective To investigate DJ-1 expression and protective effect against H2O2-induced oxidative stress in primary human melanocytes.Methods The expression and location of DJ-1 in primary melanocytes were identified by immunofluorescence.After cultured melanocytes were exposed to H2O2 for 24 hours,modified MTT assay was used to assess the proliferation of cells and to choose the suitable concentration of H2O2 for the following experiment.Western blot was used to detect D J-1 expression in melanocytes after being treated with 0.5 mmol/L H2O2 for 24 hours.Some melanocytes were divided into 3 groups to be reversely transfected with PBS(mock control group),non-targeting siRNA(negative control group)and DJ-1 targeting siRNA(DJ-1 group).Optical microscopy was utilized to observe the morphologic changes of transfected melanocytes.At 48 hours after the transfection,the melanocytes were stimulated with H2O2 for 24 hours.Subsequently,modified MTT assay,2′,7′-dichlorofluorescein diacetate(DCFH-DA)and annexin Ⅴ-fluorescein isothiocyanate/propidium iodide were used to determine cell viability,intracellular reactive oxygen species (ROS)level and apoptosis rate respectively.Results DJ-1 was expressed in both melanocyte nucleus and cytoplasm,and predominantly in the nucleus.H2O2 inhibited the cell viability in a dose dependent manner.After treatment with H2O2 of 0.5 mmol/L for 24 hours,the cell viability began to decrease in melanocytes with the expression level of DJ-1 being 2.23 times that in the untreated melanocytes(both P ＜ 0.05).Compared with the mock control group,the dendrites of melanocytes in DJ-1 group were obviously shortened with cytoplasm vacuolization.After 24-hour treatment with H2O2 of 0.5 mmol/L,the cell viability in the DJ-1 group dropped to 35％ of that in the mock control group(P ＜ 0.05),while the intracellular ROS fluorescence intensity( FI) and apoptosis rate were higher in the DJ-1 group than in the mock control group (902 ± 40 vs.529± 32,58q％ ± 6.1％ vs.30% ± 3.8％,both P ＜ 0.05).Conclusion DJ-1 can protect melanocytes against H2O2induced oxidative stress likely by decreasing intracellular ROS production and inhibiting ceU apoptosis.

RESUMEN

Objective To study to the effect of 1064-nm Q-switched Nd:YAG laser irradiation on the melanogenesis in a human epidermal melanocyte line PIG. Methods Cultured PIG cells were irradiated with 1064-nm Q-switched Nd:YAG laser (Medlite C6) at different energy densities for 10 times. After additional culture for various durations, cell viability was detected by MT assay, tyrosinase activity by dopa oxidation assay, mRNA and protein expressions of tyrosinase, tyrosinase related protein (TRP)-1 and TRP-2 by real-time quantitative fluorescent RT-PCR and Westen blotting respectively, Results The irradiation with Q-switched Nd:YAG laser at energy densities from 1 to 3 J/cm2 had no obvious effect on the viability of PIG cells. After irradiation with Nd:YAG laser at 1 J/cm2, PIG cells showed a significant increase in the tyrosinase activity,mRNA expressions of tyrosinase and TRP-1 compared with unirradiated cells (0.563 ± 0.014 vs 0.501 ±0.019, 1.40±0.11 vs 1.0, 1.28 ± 0.03 vs 1.0, all P＜ 0.05), but both the mRNA (0.91 ± 0.17 vs 1.0, P＞0.05) and protein expressions of TRP-2 experienced no significant changes before and after the irradiation.However, a significant decrease was noted in PIG cells irradiated with Nd:YAG laser at 3 J/cm2 in tyrosinase activity, mRNA and protein expressions of tyrosinase (0.70 ± 0.02 vs 1.0, 0.64 ± 0.05 vs 1.0, both P ＜ 0.05),TRP-1 (0.73±0.04 vs l.0, 0.86±0.17 vs l.0, both P＜0.05) andTRP-2 (0.68±0.04 vs l.0,0.69±0.11vs 1.0, both P ＜0.05) in comparison with unirradiated PIG cells. Conclusions The 1064-nm Q-switched Nd:YAG laser irradiation may affect the melanogenesis in PIG cells. With no influence on cell viability, the 1064-nm Q-switched Nd:YAG laser at 1 J/cm2 could enhance melanogenesis, while that at 3 J/cm2 could suppress melanogenesis, in PIG cells.