UV-irradiated Human Skin Fibroblasts Research Articles

Exosomal MiR-769-5p Exacerbates Ultraviolet-Induced Bystander Effect by Targeting TGFBR1.

Exosomal microRNAs have been investigated in bystander effect, but it is unclear whether microRNA works in ultraviolet radiation–induced bystander effects (UV-RIBEs) and what the underlying mechanism could be. Exosomes from ultraviolet (UV)–irradiated human skin fibroblasts (HSFs) were isolated and transferred to normal HSFs, followed by the detection of proliferation rate, oxidative damage level, and apoptosis rate. Exosomal miRNAs were evaluated and screened with miRNA sequencing and quantitative reverse transcriptase–polymerase chain reaction method. MiRNA shuttle and bystander photodamage reactions were observed after transfection of miR-769-5p. MiR-769-5p targeting gene transforming growth factor-β1 (TGFBR1), and TGFBR1 mRNA 3′-untranslated region (UTR) was assessed and identified by Western blotting and dual-luciferase reporter assay. Bystander effects were induced after being treated with isolated exosomes from UV-irradiated HSFs. Exosomal miR-769-5p expression was significantly upregulated. Human skin fibroblasts showed lower proliferation, increasing oxidative damage, and faster occurrence of apoptosis after transfection. Exosome-mediated transfer of miR-769-5p was observed. Upregulation of miR-769-5p induced bystander effects, whereas downregulation of miR-769-5p can suppress UV-RIBEs. In addition, miR-769-5p was found to downregulate TGFBR1 gene expression by directly targeting its 3′-UTR. Our results demonstrate that exosome-mediated miR-769-5p transfer could function as an intercellular messenger and exacerbate UV-RIBEs. MiR-769-5p inhibits the expression of TGFBR1 by targeting TGFBR1 mRNA 3′-UTR.

Effects of Macelignan Isolated from <i>Myristica fragrans</i> (Nutmeg) on Expression of Matrix Metalloproteinase-1 and Type I Procollagen in UVB-Irradiated Human Skin Fibroblasts

Exposure to ultraviolet (UV) light causes premature skin aging that is associated with upregulated matrix metalloproteinases (MMPs) and decreased collagen synthesis. Macelignan, a natural lignan compound isolated from Myristica fragrans HOUTT. (nutmeg), has been reported to possess antioxidant and antiinflammatory activities. This study assessed the effects of macelignan on photoaging and investigated its mechanisms of action in UV-irradiated human skin fibroblasts (Hs68) by reverse transcription-polymerase chain reaction, Western blot analysis, 2',7'-dichlorofluorescein diacetate assay, and enzyme-linked immunosorbent assay. Our results show that macelignan attenuated UV-induced MMP-1 expression by suppressing phosphorylation of mitogen-activated protein kinases (MAPKs) induced by reactive oxygen species. Macelignan also increased type I procollagen expression and secretion through transforming growth factor β (TGF-β)/Smad signaling. These findings indicate that macelignan regulates the expression of MMP-1 and type I procollagen in UV-irradiated human skin fibroblasts by modulating MAPK and TGF-β/Smad signaling, suggesting its potential as an efficacious antiphotoaging agent.

Ultraviolet Irradiation Induces CYR61/CCN1, a Mediator of Collagen Homeostasis, through Activation of Transcription Factor AP-1 in Human Skin Fibroblasts

UV irradiation from the sun elevates the production of collagen-degrading matrix metalloproteinases (MMPs) and reduces the production of new collagen. This imbalance of collagen homeostasis impairs the structure and function of the dermal collagenous extracellular matrix (ECM), thereby promoting premature skin aging (photoaging). We report here that aberrant dermal collagen homeostasis in UV-irradiated human skin is mediated in part by a CCN-family member, cysteine-rich protein-61 (CYR61/CCN1). CYR61 is significantly elevated in acutely UV-irradiated human skin in vivo, and UV-irradiated human skin fibroblasts. Knockdown of CYR61 significantly attenuates UV irradiation-induced inhibition of type-I procollagen and upregulation of MMP-1. Determination of CYR61 mRNA and protein indicates that the primary mechanism of CYR61 induction by UV irradiation is transcriptional. Analysis of CYR61 proximal promoter showed that a sequence conforming to the consensus binding site for transcription factor activator protein-1 (AP-1) is required for promoter activity. UV irradiation increased the binding of AP-1-family members c-Jun and c-Fos to this AP-1 site. Furthermore, functional blockade of c-Jun or knockdown of c-Jun significantly reduced the UV irradiation-induced activation of CYR61 promoter and CYR61 gene expression. These data show that CYR61 is transcriptionally regulated by UV irradiation through transcription factor AP-1, and mediates altered collagen homeostasis that occurs in response to UV irradiation in human skin fibroblasts.

Extract of Punica granatum inhibits skin photoaging induced by UVB irradiation

Punica granatum (pomegranate) is kind of a fruit consumed fresh or in beverage. It has been widely used in traditional medicine in various parts of the world. In this study, we examined the efficacy of a Punica granatum (PG) extract in protecting skin against UVB-induced damage using cultured human skin fibroblasts. A Korean red PG sample was used, and its effects classified according to if the PG source originated from the rind, seed and fruit. The polyphenol content of PG, which is known to prevent other adverse cutaneous effects of UV irradiation, was measured by GC-MS. The protective effects of PG on UVB-induced skin photoaging were examined by determining the level of procollagen type I and MMP-1 after UVB irradiation. Based on the GC-MS quantitative analysis, catechin, quercetin, kaempferol, and equol were the predominant compounds detected in PG. In the changes of expression of procollagen type I and MMP-1 in UV irradiated human skin fibroblasts treated PG, especially extract prepared from rind, the synthesis of collagen was increased and the expression of MMP-1 was decreased. The major polyphenols in PG, particularly catechin, play a significant role in its photoprotective effects on UVB-induced skin damage.

The effect of xanthorrhizol on the expression of matrix metalloproteinase‐1 and type‐I procollagen in ultraviolet‐irradiated human skin fibroblasts

Matrix metalloproteinases (MMPs) are key regulators of the skin photoaging process that is set in motion by exposure to ultraviolet (UV) irradiation. This skin damage results from UV-induced generation of reactive oxygen species, which are associated with upregulation of MMPs and decreased collagen synthesis. We investigated the effects of xanthorrhizol, isolated from Curcuma xanthorrhiza, on the expression of MMP-1 and type-I procollagen in UV-irradiated human skin fibroblasts. Fibroblasts cultured in the presence or absence of purified xanthorrhizol or C. xanthorrhiza extract were irradiated with UV (20 mJ/cm(2)), and MMP-1 and type-I procollagen levels were measured using Western blot analysis. Xanthorrhizol (0.001-0.1 microM) and C. xanthorrhiza extract (0.01-0.5 microg/mL) induced a significant, dose-dependent decrease in the expression of MMP-1 protein, and increased the expression of type-1 procollagen. At a concentration of 0.1 microM, xanthorrhizol nearly completely abrogated MMP-1 expression. The MMP-1-suppressing and type-1 procollagen-inducing effects of xanthorrhizol treatment were greater than those of epigallocatechin 3-O-gallate (EGCG), which is known to be a natural anti-aging agent. These results suggest that xanthorrhizol is a potential candidate for the prevention and treatment of skin aging.

The effect of 4-hydroxypanduratin A on the mitogen-activated protein kinase-dependent activation of matrix metalloproteinase-1 expression in human skin fibroblasts

Background Exposure of ultraviolet (UV) light on the skin induces photoaging associated with up-regulated matrix metalloproteinases (MMPs) activities. The MMP-1 expression due to UV irradiation can be mediated by mitogen-activated protein kinases (MAPKs) such as extracellular signal-regulated kinase (ERK), Jun-N-terminal kinase (JNK) and p38 kinase activation. Objective We investigated the effects of 4-hydroxypanduratin A, isolated from Kaempferia pandurata Roxb., on the expression of MMP-1 and activation of MAPKs signal pathways in UV-irradiated human skin fibroblasts. Methods The fibroblasts were treated with 4-hydroxypanduratin A for indicated times and the cells were irradiated with UVB. MMP-1 protein expression and phosphorylation of MAPKs were determined by Western blot. Activator protein-1 (AP-1) DNA binding activity was investigated using electrophoretic mobility shift assay (EMSA). Results 4-Hydroxypanduratin A in the range of 0.001–0.1 μM significantly reduced the expression of MMP-1 levels and inhibited UV-induced MAPKs activation. Moreover, inhibition of MAPKs by 4-hydroxypanduratin A resulted in decreasing c-Fos expression and c-Jun phosphorylation induced by UV, which led to inhibiting AP-1 DNA binding activity. Conclusions The results suggest that 4-hydroxypanduratin A can be a potential candidate for the prevention and treatment of skin aging brought about by UV.

Inhibitory Effect of Panduratin A on UV-induced Activation of Mitogen-Activated Protein Kinases (MAPKs) in Dermal Fibroblast Cells

Exposure of the skin to ultraviolet (UV) induces photoaging associated with up-regulated matrix metalloproteinases (MMPs) activities and decreased collagen synthesis. We previously reported that panduratin A, a chalcone compound isolated from KAEMPFERIA PANDURATA Roxb ., decreased MMP-1 expression in UV-irradiated human skin fibroblasts. Here, we have investigated the effect of panduratin A on UV-induced activation of mitogen-activated protein kinases (MAPKs) signaling modules such as extracellular-regulated protein kinase (ERK), Jun-N-terminal kinase (JNK) and p38 kinase. Treatment with panduratin A in the range of 0.001 - 0.1 microM significantly inhibited UV-induced ERK, JNK and p38 activation. Moreover, inhibition of ERK, JNK and p38 by panduratin A resulted in decreased c-Fos expression and c-Jun phosphorylation induced by UV, which led to inhibition of activator protein-1 (AP-1) DNA binding activity. Panduratin A showed stronger activity than epigallocatechin 3- O-gallate (EGCG) known as a natural anti-aging agent. The results suggest that panduratin A can down-regulate UV-induced MMP-1 expression by inhibiting the MAPKs pathways and AP-1 activation. AP-1:activator protein-1 EGCG:epigallocatechin 3- O-gallate ERK:extracellular-regulated protein kinase JNK:c-Jun N-terminal kinase MAPK:mitogen-activated protein kinase MMP:matrix metalloproteinase UV:ultraviolet.

The Effects of Panduratin A Isolated from Kaempferia pandurata on the Expression of Matrix Metalloproteinase-1 and Type-1 Procollagen in Human Skin Fibroblasts

Exposure of ultraviolet (UV) light on the skin induces photoaging associated with up-regulated matrix metalloproteinase (MMP) activities and decreased collagen synthesis. We investigated the effects of panduratin A isolated from Kaempferia pandurata Roxb. on the expression of matrix metalloproteinase-1 (MMP-1) and type-1 procollagen in UV-irradiated human skin fibroblasts. Cultured human fibroblasts were irradiated with UV (20 mJ/cm (2)) and panduratin A was added into the medium of the fibroblast culture. The expressions of MMP-1 and type-1 procollagen levels were measured using Western blot analysis and RT-RCR. Panduratin A in the range of 0.001 - 0.1 microM significantly reduced the expression of MMP-1 and induced the expression of type-1 procollagen at the protein and mRNA gene levels. Panduratin A showed stronger activity than epigallocatechin 3- O-gallate (EGCG) known as a natural anti-aging agent. The results suggest that panduratin A can be a potential candidate for the prevention and treatment of skin aging brought about by UV.

RETRACTED: The effect of sativan from Viola verecunda A. GRAY on the expressions of matrix metalloproteinase-1 cause by ultraviolet irradiated cultured primary human skin fibroblasts

Matrix metalloproteinases (MMPs) are a family of enzymes whose main function is degradation of the extracellular matrix. Matrix metalloproteinase-1 (MMP-1) degrades type I procollagen constituting the major structural component of the basement membrane and extra cellular membrane. The enzymatic activity is found to be elevated in photoaging. With the aim of finding novel MMP-1 inhibitors from natural products, 15 extracts of the Viola taxa, which are used as prescriptions for skin eruption treatment in traditional medicine, were screened for their inhibitory activities towards MMP-1. Among the 15 tested materials, the methanol extracts of Viola hondoensis W. BECKER et H. BOISS, Viola ibukiana MAKINO, Viola lactiflora NAKAI and Viola verecunda A. GRAY were potential inhibitory to MMP-1, and other Viola taxa showed a weak inhibitory effect at a concentration of 100 microg/ml. We investigated the effect of MMP-1 inhibitory of the solvent fractions of the same plants (Viola hondoensis, Viola ibukiana and Viola verecunda). Therefore, a strong inhibition was found in the ethylacetate fractions of Viola verecunda with inhibitory activity (>90%) at a concentration of 10 microg/ml. Here we investigated the effect of sativan isolated from the ethylacetate fractions of Viola verecunda on the expression of MMPs in UV-irradiated human skin fibroblasts in vitro. Sativan markedly reduced UV-induced MMP-1 expression at the protein levels in a dose-dependent manner. Our report is the first description for the ability of sativan to regulate UV-induced MMP-1 expression.

RETRACTED: The effect of flavonol glycoside on the expressions of matrix metalloproteinase-1 in ultraviolet-irradiated cultured human skin fibroblasts

Long-term and repeated exposure of ultraviolet (UV) light, a harmful environmental stress, on the skin often induces chronic skin diseases, such as skin cancer as well as photo-aging (premature skin aging), and the mechanisms of these skin damages are closely associated with up-regulation of matrix metalloproteinases (MMPs) activities. Here, we investigated the effect of quercetin-3-O-beta-d-(6''-feruloyl)-galactopyranoside isolated from the stems of Viola hondoensis (Violaceae) on the expression of MMPs in UV-irradiated human skin fibroblasts in vitro. Quercetin-3-O-beta-d-(6''-feruloyl)-galactopyranoside markedly reduced UV-induced MMP-1 expression at the protein levels in a dose-dependent manner. Our report is the first description for the ability of quercetin-3-O-beta-d-(6''-feruloyl)-galactopyranoside to regulate UV-induced MMP-1 expression.

Isoflavonoid from Viola hondoensis, Regulates the Expression of Matrix Metalloproteinase-1 in Human Skin Fibroblasts

Long term and repeated exposure of ultraviolet (UV) light, a harmful environmental stress, on the skin often induces chronic skin diseases such as skin cancer as well as photoaging (premature skin aging), and the mechanisms of these skin damages are closely associated with up-regulation of matrix metalloproteinases (MMPs) activities. Here we investigated the effect of 2',4',7-trihydroxyisoflavone isolated from the whole plants of Viola hondoensis (Violaceae) on the expression of MMPs in UV-irradiated human skin fibroblasts in vitro. 2',4',7-Trihydroxyisoflavone markedly reduced UV-induced MMP-1 expression, but not MMP-2, at the both mRNA and protein levels in a dose-dependent manner. Our report is the first description for the ability of 2',4',7-trihydroxyisoflavone to regulate MMP-1 expression specifically.

Mapping of UV photoproducts along the human P53 gene.

Methods to detect DNA adducts at the DNA sequence level in mammalian cells have been developed, and it is now possible to relate adduct frequency and repair efficiency with mutations at certain nucleotide positions in human cancer-relevant genes. Mutations in the p53 tumor suppressor gene have been found in a large proportion of human skin cancers. These mutations are predominantly C to T transitions and CC to TT double transition mutations, two types of base alterations specifically induced by UV light. In order to find possible correlations between adduct distribution and mutations at specific p53 sequences, we have mapped at single-base resolution the distribution of cyclobutane dimers (CBD) and (6-4) photoproducts along the p53 gene in UV-irradiated human skin fibroblasts by ligation-mediated polymerase chain reaction (LMPCR).

Disruption of cytoplasmic microtubules by ultraviolet radiation

Ultraviolet (UV) irradiation of cultured human skin fibroblasts causes the disassembly of their microtubules. Using indirect immunofluorescence microscopy, we have now investigated whether damage to the microtubule precursor pool may contribute to the disruption of microtubules. Exposure to polychromatic UV radiation inhibits the reassembly of microtubules during cellular recovery from cold treatment. In addition, the ability of taxol to promote microtubule polymerization and bundling is inhibited in UV-irradiated cells. However, UV irradiation of taxol-pretreated cells or in situ detergent-extracted microtubules fails to disrupt the microtubule network. These data suggest that damage to dimeric tubulin, or another soluble factor(s) required for polymerization, contributes to the disassembly of microtubules in UV-irradiated human skin fibroblasts.

Environmental Wavelengths of Ultraviolet Light Induce Cytoskeletal Damage

The ultraviolet component of sunlight is the major cause of skin cancer and is responsible for accelerating the aging of human skin. It is therefore important to determine the mechanisms by which ultraviolet light alters normal cellular functions. The potential importance of ultraviolet light-induced damage to non-DNA targets has received little attention. Since the cytoskeleton is an important participant in the control of normal cell growth, the microfilaments and microtubules of UV irradiated human skin fibroblasts have been studied using fluorescence microscopy. Polychromatic ultraviolet light, composed of environmentally relevant wavelengths, was found to disrupt the cytoplasmic microtubule complex in a dose dependent manner. The induction of microtubule disassembly did not correlate with the cytotoxicity of ultraviolet light of varying composition.