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1.
Int J Food Sci Nutr ; 73(4): 460-470, 2022 Jun.
Article in English | MEDLINE | ID: mdl-34719319

ABSTRACT

Oleuropein (OLE) and hydroxytyrosol (HT) are dietary polyphenols with skin beneficial effects but their effects on skin-ageing-related enzymes are not clear. Herein, we evaluated their inhibitory effects on elastase and collagenase. OLE and HT (62.5-1 000 µM) showed moderate anti-elastase and anti-collagenase effects (5.1-26.3%, 5.8-12.2% and 12.6-31.0%, 11.6-31.9% inhibition, respectively). Combinations of OLE and HT (1:1 ratio) exerted synergistic inhibitory effects on elastase, which were supported by their combination index (CI), kinetic assay and computational docking. Moreover, HT (100 µM) reduced hydrogen peroxide (H2O2)-induced cytotoxicity and reactive oxygen species (ROS) in human dermal fibroblast cells by 21.8 and 15.2%, respectively. In addition, combinations of OLE and HT (6.25/6.25-100/100 µM) exerted synergistic cytoprotective effects by reducing ROS levels by 7.6-37.3% with CIs of 0.17-0.44, respectively. The findings from this study support the cosmeceutical activities of OLE and HT but further research is warranted to evaluate their anti-skin-ageing effects using in vivo models.


Subject(s)
Antioxidants , Polyphenols , Antioxidants/pharmacology , Fibroblasts , Humans , Hydrogen Peroxide , Iridoid Glucosides , Iridoids/pharmacology , Matrix Metalloproteinase Inhibitors , Pancreatic Elastase , Phenylethyl Alcohol/analogs & derivatives , Polyphenols/pharmacology , Reactive Oxygen Species
2.
Biochem Biophys Res Commun ; 576: 100-107, 2021 10 22.
Article in English | MEDLINE | ID: mdl-34482022

ABSTRACT

RATIONALE: Coronary artery ligation to induce myocardial infarction (MI) and ischemia injury in mice is typically performed in normal mice, but This is not consistent with disease progression. There should be atherosclerosis (AS) first, followed by MI. OBJECTIVE: We tried a novel model to induce MI that was established on atherosclerosis in mice. This approach was much more consistent with disease progression. METHODS: In this study, Mice lacking apolipoprotein E (ApoE-/-) were randomly divided into four groups. The mice of the control and MI groups were fed normal diet for 24-weeks, while the mice of AS and AS + MI groups were fed high-fat diet (HFD). After 23 weeks, the mice of MI and AS + MI groups were ligated with coronary arteries. A week later, after echocardiography, analysis of plaque and myocardium were conducted on aortic and heart, then the serum, aorta and heart tissues were further detected. RESULTS: Our results showed that AS model mice exhibited significant body weight gain, dyslipidemia and atherosclerotic lesions formation which were in accordance with the pathological changes of AS. Co-treatment with AS and MI led to higher operative mortality and heart pathological were in accordance with the pathological changes of MI. In addition, Echocardiography and NT pro-BNP revealed co-treatment with AS and MI led to deterioration of cardiac function. AS also aggravated myocardial inflammatory cell infiltration and fibrosis post-MI. CONCLUSIONS: Together, it is feasible to establish myocardial infarction model based on atherosclerosis model.


Subject(s)
Atherosclerosis/pathology , Diet, High-Fat , Disease Models, Animal , Dyslipidemias/physiopathology , Mice, Knockout, ApoE/genetics , Myocardial Infarction/pathology , Animals , Atherosclerosis/metabolism , Disease Progression , Female , Mice , Mice, Inbred C57BL , Mice, Knockout, ApoE/metabolism , Myocardial Infarction/metabolism
3.
Am J Dermatopathol ; 43(12): 942-944, 2021 Dec 01.
Article in English | MEDLINE | ID: mdl-34291739

ABSTRACT

ABSTRACT: Acquired perforating dermatoses (APDs) are a group of diverse skin disorders in patients with systemic disease, most commonly chronic renal failure and diabetes mellitus. APD induced by medication has seldom been reported. Anti-PD-1 monoclonal antibody has recently been used as a broad-spectrum, effective, durable, and relatively safe antitumor therapy for various malignancies. Thus far, known side effects involving skin have included rash, pruritus, and vitiligo. Here, we present a rare case of a unilateral linear eruption with histopathologic features of APD in a 36-year-old man during treatment with Terepril monoclonal antibody. To the best of our knowledge, APD induced by the PD-1 inhibitor has not been described in the medical literature.


Subject(s)
Drug Eruptions/pathology , Immune Checkpoint Inhibitors/adverse effects , Skin Diseases/chemically induced , Skin Diseases/pathology , Adenocarcinoma/drug therapy , Adult , Colonic Neoplasms/drug therapy , Drug Eruptions/etiology , Humans , Male
4.
Dermatol Ther ; 33(3): e13426, 2020 05.
Article in English | MEDLINE | ID: mdl-32301192

ABSTRACT

Reactive carbonyl species including methylglyoxal (MGO) are oxidation metabolites of glucose and precursors of advanced glycation end products (AGEs). They are important mediators of cellular oxidative stress and exacerbate skin complications. Published data supports that certain phenolic compounds can exert cellular protective effects by their antioxidant activity. A phenolic-enriched maple syrup extract (MSX) was previously reported to show protective effects against AGEs- and MGO-induced cytotoxicity in human colon cells but its skin protective effects remain unknown. The protective effects of MSX were evaluated against hydrogen peroxide (H2 O2 )- and MGO-induced cytotoxicity in human keratinocytes (HaCaT cells). Cellular viability and antioxidant activity were evaluated by the luminescent cell viability CellTiter-Glo assay and the reactive oxygen species (ROS) assay, respectively. A single-cell gel electrophoresis (Comet assay) was used to measure the strand breaks in the DNA of HaCaT cells. MSX (at 50 µg/mL) ameliorated H2 O2 - and MGO-induced cytotoxicity by increasing cell viability by 21.5% and 25.9%, respectively. MSX reduced H2 O2 - and MGO-induced ROS production by 69.4% and 56.6%, respectively. MSX also reduced MGO-induced DNA damage by 47.5%. MSX showed protective effects against H2 O2 - and MGO-induced cytotoxicity in HaCaT cells supporting its potential for dermatological and/or cosmeceutical applications.


Subject(s)
Acer , Pyruvaldehyde , Humans , Hydrogen Peroxide/toxicity , Keratinocytes , Oxidative Stress , Plant Extracts/pharmacology , Pyruvaldehyde/toxicity , Reactive Oxygen Species
5.
BMC Cancer ; 18(1): 1078, 2018 Nov 07.
Article in English | MEDLINE | ID: mdl-30458743

ABSTRACT

BACKGROUND: Extramammary Paget's disease (EMPD), a rare skin malignancy with non-specific manifestations, is often misdiagnosed as eczema of scrotum or tinea cruris. Although the diagnosis of EMPD could be confirmed by biopsy, it can be delayed as patients are reluctant to receive invasive operations. Herein, we investigated the serum miRNA expressions of EMPD patients and compared to that of the eczema of scrotum or tinea cruris patients as well as health volunteers for potential diagnostic markers for EMPD. METHODS: Altogether 45 subjects including 16 patients diagnosed with EMPD, 12 patients diagnosed with eczema of scrotum or tinea cruris and 17 healthy volunteers were enrolled in this study. Serum from all of subjects were collected to identify miRNAs (by miRNA array global normalization, RT-PCR validation, and receiver operating characteristic curve analysis) that could be potential diagnostic markers for EMPD. RESULTS: The miRNA array analyses revealed that the expressions of 37 miRNAs from the EMPD patients were different (change ≥4-fold) from health volunteers. Among these miRNAs, the expression of miR-155 was significantly increased (p < 0.01) in the EMPD patients as compared with that of the health volunteers and the eczema of scrotum or the tinea cruris patients (no difference between these two control groups). In addition, receiver operating characteristic (ROC) curve analysis showed that diagnostic capacities (defined as the area under curve of ROC) of miR-155 are 0.85 (as compared with health volunteers group) and 0.81 (as compared with the eczema of scrotum or the tinea cruris patients group), respectively. CONCLUSION: The serum miRNA expression of gene miR-155 in the EMPD patients was differentiated from that of other subjects warranting further validation of miR-155 as a diagnostic marker of EMPD.


Subject(s)
Biomarkers, Tumor/genetics , MicroRNAs/genetics , Paget Disease, Extramammary/genetics , Skin Neoplasms/genetics , Aged , Biomarkers, Tumor/blood , Diagnosis, Differential , Eczema/diagnosis , Eczema/genetics , Female , Gene Expression , Humans , Male , MicroRNAs/blood , Middle Aged , Paget Disease, Extramammary/blood , Paget Disease, Extramammary/diagnosis , ROC Curve , Reverse Transcriptase Polymerase Chain Reaction , Scrotum/metabolism , Scrotum/pathology , Skin Neoplasms/blood , Skin Neoplasms/diagnosis , Tinea/diagnosis , Tinea/genetics
6.
J Nanosci Nanotechnol ; 16(6): 6258-64, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27427699

ABSTRACT

Curcumin, a polyphenol extracted from turmeric (Curcuma longa), has emerged as a potent multimodal cancer-preventing agent. It may attenuate the spread of cancer and render chemotherapy more effective. However, curcumin is neither well absorbed nor well retained in the blood, resulting in low efficacy. In an attempt to enhance the potency and to improve the bioavailability of curcumin, new delivery agents, hydroxypropyl-beta-cyclodextrin (HP-ß-CD)-modified GoldMag nanoparticles (CD-GMNs) were designed and synthesized to incorporate curcumin. The CD-GMNs were characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Thermo-gravimetric Analysis (TGA), X-ray Diffraction (XRD), Dynamic Light Scattering measurements (DLS), Transmission Electron Microscopy (TEM) and Vibrating Sample Magnetometer (VSM) analyses. For the magnetic carrier of CD-GMNs, the content of HP-ß-CD was 26.9 wt%. CD-GMNs have a saturation magnetization of 22.7 emu/g with an average hydrodynamic diameter of 80 nm. The curcumin loading, encapsulation efficiency and releasing properties in vitro were also investigated. The results showed that the drug encapsulation ratio was 88% and the maximum curcumin loading capacity of CD-GMNs was 660 µg/5 mg. In vitro drug release studies showed a controlled and pH-sensitive curcumin release over a period of one week. Collectively, our data suggest that HP-ß-CD-modified GoldMag nanoparticles can be considered to form a promising delivery system for curcumin to tumor sites. Targeting can be achieved by the combined effects of the application of an external magnetic field and the effect on drug release of lower pH values often found in the tumor microenvironment.


Subject(s)
Curcumin/chemistry , Drug Carriers/chemistry , Drug Carriers/chemical synthesis , Gold/chemistry , Magnetite Nanoparticles/chemistry , beta-Cyclodextrins/chemistry , beta-Cyclodextrins/chemical synthesis , 2-Hydroxypropyl-beta-cyclodextrin , Chemistry Techniques, Synthetic , Drug Liberation , Hydrophobic and Hydrophilic Interactions
7.
Antioxidants (Basel) ; 13(4)2024 Apr 17.
Article in English | MEDLINE | ID: mdl-38671925

ABSTRACT

Cannabis and its major cannabinoid cannabidiol (CBD) are reported to exhibit anticancer activity against skin tumors. However, the cytotoxic effects of other minor cannabinoids and synthetic CBD derivatives in melanoma are not fully elucidated. Herein, the antiproliferative activity of a panel of phytocannabinoids was screened against murine (B16F10) and human (A375) melanoma cells. CBD was the most cytotoxic natural cannabinoid with respective IC50 of 28.6 and 51.6 µM. Further assessment of the cytotoxicity of synthetic CBD derivatives in B16F10 cells identified two bipiperidinyl group-bearing derivatives (22 and 34) with enhanced cytotoxicity (IC50 = 3.1 and 8.5 µM, respectively). Furthermore, several cell death assays including flow cytometric (for apoptosis and ferroptosis) and lactate dehydrogenase (for pyroptosis) assays were used to characterize the antiproliferative activity of CBD and its bipiperidinyl derivatives. The augmented cytotoxicity of 22 and 34 in B16F10 cells was attributed to their capacity to promote apoptosis (as evidenced by increased apoptotic population). Taken together, this study supports the notion that CBD and its derivatives are promising lead compounds for cannabinoid-based interventions for melanoma management.

9.
ACS Appl Bio Mater ; 5(11): 5231-5239, 2022 11 21.
Article in English | MEDLINE | ID: mdl-36331184

ABSTRACT

Optical tissue phantoms present substantial value for medical imaging and therapeutic applications. We have developed an epidermal tissue phantom to mimic the optical properties of human skin from the ultraviolet to the infrared region, exceeding the breadth of existing studies. An epoxy matrix is combined with melanin-mimicking polydopamine via a cost-effective fabrication strategy. Reflectance and transmittance measurements enable calculation of the wavelength-dependent complex refractive index and absorption coefficient. Results are compared with literature data to establish agreement with a real human epidermis. By analyzing emissive power at a typical skin temperature, the epidermal tissue phantom is shown to accurately mimic the radiative properties of human skin. This simple, multifunctional material represents a promising substitute for human tissue for a variety of medical and bioengineering applications.


Subject(s)
Epidermis , Skin , Humans , Skin/diagnostic imaging , Epidermal Cells , Biomedical Engineering , Melanins
10.
Int J Mol Med ; 49(2)2022 Feb.
Article in English | MEDLINE | ID: mdl-34878147

ABSTRACT

Following the publication of the above article, an interested reader drew to the authors' attention that the Transwell cell migration assay data shown in Fig. 4A appeared to be partly overlapping with data presented for experiments performed under different experimental conditions in Figs. 4D and E. The authors independently examined the figure and realized that inadvertent errors had been made during the assembly of Fig. 4; furthermore, owing to the time that has elapsed since this paper was published, the authors no longer had access to the original data. Accordingly, to further verify the conclusions reported in the study, the authors repeated these experiments, and the results obtained were found to be consistent with the original findings. The new version of Fig. 4 is shown below. The authors are grateful to the Editor of International Journal of Molecular Medicine for allowing them the opportunity to publish this Corrigendum, and apologize to the readership for any inconvenience caused. [the original article was published in International Journal of Molecular Medicine 26: 57-65, 2010; DOI: 10.3892/ijmm_00000435].

11.
J Biol Chem ; 285(19): 14842, 2010 May 07.
Article in English | MEDLINE | ID: mdl-29874310

ABSTRACT

[This retracts the article on p. 28897 in vol. 283, PMID: 18715874.].

12.
Biochem Biophys Res Commun ; 414(3): 499-505, 2011 Oct 28.
Article in English | MEDLINE | ID: mdl-21968016

ABSTRACT

Patients with age related macular degeneration (AMD) have a loss of vision in the center of the visual field. Oxidative stress plays an important role in this progress. Nerve growth factor (NGF) is important for the survival and maintenance of sympathetic and sensory neurons and NGF eye drops improve visual acuity and electro-functional activity in patients with AMD. However, the molecular mechanisms and signaling events involved in this have not been fully investigated. Using cultured human retinal pigment epithelial (RPE) cells, we demonstrate here that NGF protects RPE cells against hydrogen peroxide (H(2)O(2))-induced cell apoptosis. NGF also induces RPE cell migration, the latter is important for retinal regeneration and the recovery from AMD. H(2)O(2) decreases S6 phosphorylation and cell viability, which is restored by NGF. Rapamycin, the pharmacologic inhibitor of mammalian target of rapamycin (mTOR), diminished NGF-induced S6 phosphorylation, cell migration and protective effects against oxidative stress. Collectively, we conclude that activation of rapamycin sensitive mTOR signaling mediates NGF induced cell migration and pro-survival effects in H(2)O(2) treated RPE cells.


Subject(s)
Hydrogen Peroxide/antagonists & inhibitors , Nerve Growth Factor/pharmacology , Oxidative Stress/drug effects , Proto-Oncogene Proteins c-akt/antagonists & inhibitors , Retinal Pigment Epithelium/enzymology , TOR Serine-Threonine Kinases/biosynthesis , Apoptosis/drug effects , Cell Line , Cell Movement/drug effects , Cell Survival/drug effects , Cytoprotection , Enzyme Activation , Humans , Hydrogen Peroxide/pharmacology , Macular Degeneration/enzymology , Phosphatidylinositol 3-Kinases/metabolism , Phosphoinositide-3 Kinase Inhibitors , Proto-Oncogene Proteins c-akt/metabolism , Retinal Pigment Epithelium/drug effects , Sirolimus/pharmacology , TOR Serine-Threonine Kinases/antagonists & inhibitors
13.
Am J Chin Med ; 49(7): 1683-1701, 2021.
Article in English | MEDLINE | ID: mdl-34521318

ABSTRACT

Helianthus Annuus L. (HAL) is composed of flavonoids and polysaccharides. Flavonoids have demonstrated beneficial effects on atherosclerosis (AS). The objective of this study was to investigate the anti-atherosclerosis effect and the related mechanism of HAL. In this study, the AS model induced by high-fat diet (HFD) mice that lacked apolipoprotein E (Apoe[Formula: see text] received feed containing 5% HAL for 24 weeks. After administration, the analysis of plaque on aorta was conducted, and the possible mechanisms were further explored. With HAL treatment, the size of atherosclerotic lesions in HFD-induced AS model mice was reduced. HAL ameliorated dyslipidemia and decreased the combined ratio. HAL up-regulated concentrations of superoxide dismutase (SOD), nitric oxide (NO) and glutathione peroxidase (GSH-Px) and down-regulated concentrations of malondialdehyde (MDA) in the aorta. In addition, 16S rRNA analysis showed that HAL also reduced diversity of the intestinal microbiota, decreased the Firmicutes-to-Bacteroidetes ratio, and increased the relative abundance of probiotics such as Akkermansia muciniphila and Lactobacillus. In the end, HAL decreased the permeability of intestine by increasing the levels of occludin and tight junction protein 1 (ZO-1) in the colon, consequently decreasing concentration of interleukin (IL)-6, IL-1[Formula: see text] and tumor necrosis factor-alpha (TNF-[Formula: see text] in serum and mRNA expressions in the aorta. Data showed that HAL alleviates AS by restraining oxidative stress, regulating intestinal microbiota, decreasing intestinal permeability and inhibiting inflammation. Our findings provided novel insights into the role and mechanism of anti-atherogenic potential of HAL.


Subject(s)
Atherosclerosis/drug therapy , Gastrointestinal Microbiome/drug effects , Helianthus , Inflammation/drug therapy , Oxidative Stress/drug effects , Plant Extracts/pharmacology , Animals , Diet, High-Fat , Disease Models, Animal , Down-Regulation , Mice , Up-Regulation
14.
Nanoscale ; 13(42): 17754-17764, 2021 Nov 04.
Article in English | MEDLINE | ID: mdl-34553203

ABSTRACT

Water scarcity and waste mismanagement are global crises that threaten the health of populations worldwide and a sustainable future. In order to help mitigate both these issues, a solar desalination device composed entirely of fallen leaves and guar - both natural materials - has been developed and demonstrated herein. This sustainable desalinator realizes an evaporation rate of 2.53 kg m-2 h-1 under 1 sun irradiance, and achieves consistent performance over an extended exposure period. Furthermore, it functions efficiently under a variety of solar intensities and in high salinity environments, and can produce water at salinities well within the acceptable levels for human consumption. Such strong performance in a large variety of environmental conditions is made possible by its excellent solar absorption, superb and rapid water absorption, low thermal conductivity, and considerable salt rejection abilities. Composed primarily of biowaste material and boasting a simple fabrication process, this leaf-guar desalinator provides a low-cost and sustainable avenue for alleviating water scarcity and supporting a green path forward.

15.
ACS Omega ; 6(50): 34555-34562, 2021 Dec 21.
Article in English | MEDLINE | ID: mdl-34963940

ABSTRACT

Water shortage is a critical global issue that threatens human health, environmental sustainability, and the preservation of Earth's climate. Desalination from seawater and sewage is a promising avenue for alleviating this stress. In this work, we use the hornet nest envelope material to fabricate a biomass-based photothermal absorber as part of a desalination isolation system. This system realizes an evaporation rate of 3.98 kg m-2 h-1 under one-sun illumination, with prolonged evaporation rates all above 4 kg m-2 h-1. This system demonstrates a strong performance of 3.86 kg m-2 h-1 in 3.5 wt % saltwater, illustrating its effectiveness in evaporation seawater. Thus, with its excellent evaporation rate, great salt rejection ability, and easy fabrication approach, the hornet nest envelope constitutes a promising natural material for solar water treatment applications.

16.
Food Funct ; 11(6): 5105-5114, 2020 Jun 24.
Article in English | MEDLINE | ID: mdl-32356551

ABSTRACT

Phytochemicals from functional foods are common ingredients in dietary supplements and cosmetic products for anti-skin aging effects due to their antioxidant activities. A proprietary red maple (Acer rubrum) leaf extract (Maplifa™) and its major phenolic compound, ginnalin A (GA), have been reported to show antioxidant, anti-melanogenesis, and anti-glycation effects but their protective effects against oxidative stress in human skin cells remain unknown. Herein, we investigated the cytoprotective effects of Maplifa™ and GA against hydrogen peroxide (H2O2) and methylglyoxal (MGO)-induced oxidative stress in human keratinocytes (HaCaT cells). H2O2 and MGO (both at 400 µM) induced toxicity in HaCaT cells and reduced their viability to 59.2 and 61.6%, respectively. Treatment of Maplifa™ (50 µg mL-1) and GA (50 µM) increased the viability of H2O2- and MGO-treated cells by 22.0 and 15.5%, respectively. Maplifa™ and GA also showed cytoprotective effects by reducing H2O2-induced apoptosis in HaCaT cells by 8.0 and 7.2%, respectively. The anti-apoptotic effect of Maplifa™ was further supported by the decreased levels of apoptosis associated enzymes including caspases-3/7 and -8 in HaCaT cells by 49.5 and 19.0%, respectively. In addition, Maplifa™ (50 µg mL-1) and GA (50 µM) reduced H2O2- and MGO-induced reactive oxygen species (ROS) by 84.1 and 56.8%, respectively. Furthermore, flow cytometry analysis showed that Maplifa™ and GA reduced MGO-induced total cellular ROS production while increasing mitochondria-derived ROS production in HaCaT cells. The cytoprotective effects of Maplifa™ and GA in human keratinocytes support their potential utilization for cosmetic and/or dermatological applications.


Subject(s)
Acer/chemistry , Deoxyglucose/analogs & derivatives , Gallic Acid/analogs & derivatives , Hydrogen Peroxide/toxicity , Keratinocytes/metabolism , Oxidative Stress , Plant Extracts/pharmacology , Pyruvaldehyde/toxicity , Apoptosis/drug effects , Caspases/metabolism , Cell Line , Cytoprotection , Deoxyglucose/pharmacology , Down-Regulation , Gallic Acid/pharmacology , Humans , Keratinocytes/drug effects , Mitochondria/metabolism , Plant Leaves/chemistry , Reactive Oxygen Species/metabolism
17.
Nanoscale ; 12(18): 10098-10105, 2020 May 14.
Article in English | MEDLINE | ID: mdl-32350488

ABSTRACT

Rapid and simple detection of single nucleotide polymorphism (SNP) is vital for individualized diagnosis and eventual treatment in the current clinical setting. In this study, we developed a tetra-primer ARMS-PCR combined lateral flow assay (T-ARMS-PCR-LFA) method for simultaneous visual detection of two alleles. By using four primers labeled with digoxin, biotin and Cy5 separately in one PCR reaction, the amplified allele-specific products could be captured by streptavidin and the anti-Cy5 antibody on two separated test lines of a LFA strip, which allows the presentation of both alleles within the single LFA strip. Both DNA and whole blood can be used as templates in this genotyping method in which the whole detection process is completed within 75 minutes. The performance assay of T-ARMS-PCR-LFA demonstrates the accuracy, specificity and sensitivity of this method. One hundred human whole blood samples were used for MTHFR C677T genotyping in T-ARMS-PCR-LFA. The concordance rate of the results detected was up to 100% when compared with that of the sequencing results. Collectively, this newly developed method is highly applicable for SNP screening in clinical practices.


Subject(s)
DNA/metabolism , Methylenetetrahydrofolate Reductase (NADPH2)/genetics , Polymerase Chain Reaction/methods , Alleles , Antibodies/chemistry , Antibodies/immunology , DNA/blood , DNA Primers/chemistry , DNA Primers/metabolism , Digoxin/chemistry , Digoxin/immunology , Genotype , Humans , Polymorphism, Single Nucleotide
18.
J Cell Mol Med ; 13(9B): 3632-43, 2009 Sep.
Article in English | MEDLINE | ID: mdl-18681908

ABSTRACT

SIRT1 is a member of a highly conserved gene family (sirtuins) encoding nicotinamide adenine dinucleotide (NAD)(+)-dependent deacetylases, originally found to deacetylate histones leading to increased DNA stability and prolonged survival in yeast and higher organisms, including mammals. SIRT1 has been found to function as a deacetylase for numerous protein targets involved in various cellular pathways, including stress responses, apoptosis and axonal degeneration. However, the role of SIRT1 in ultraviolet (UV) signalling pathways remains unknown. Using cell culture and Western blot analysis in this study we found that SIRT1 is expressed in cultured human skin keratinocytes. Both UV radiation and H(2)O(2), two major inducers of skin cell damage, down-regulate SIRT1 in a time- and dose-dependent manner. We observed that reactive oxygen species-mediated JNK activation is involved in this SIRT1 down-regulation. SIRT1 activator, resveratrol, which has been considered as an important antioxidant, protects against UV- and H(2)O(2)-induced cell death, whereas SIRT inhibitors such as sirtinol and nicotinamide enhance cell death. Activation of SIRT1 negatively regulates UV- and H(2)O(2)-induced p53 acetylation, because nicotinamide and sirtinol as well as SIRT1 siRNA enhance UV- and H(2)O(2)-induced p53 acetylation, whereas SIRT1 activator resveratrol inhibits it. We also found that SIRT1 is involved in UV-induced AMP-activated protein kinase (AMPK) and downstream acetyl-CoA carboxylase (ACC), phosphofructose kinase-2 (PFK-2) phosphorylation. Collectively, our data provide new insights into understanding of the molecular mechanisms of UV-induced skin aging, suggesting that SIRT1 activators such as resveratrol could serve as new anti-skin aging agents.


Subject(s)
Cells, Cultured/metabolism , Gene Expression Regulation , Hydrogen Peroxide/pharmacology , MAP Kinase Kinase 4/metabolism , Sirtuin 1/metabolism , Skin/cytology , Tumor Suppressor Protein p53/metabolism , Animals , Cell Death , Cell Proliferation , Dose-Response Relationship, Drug , Humans , Mice , Reactive Oxygen Species
19.
J Cell Physiol ; 220(2): 277-84, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19360745

ABSTRACT

Epidemiological and experimental evidence has supported the notion that solar ultraviolet (UV) radiation is the leading cause of skin cell damage and skin cancer. Non-melanoma skin cancer, one of the malignancies with the most rapidly increasing incidence, is suggested to be directly related to the total exposure to solar UV light. Over the past few years, the mechanisms of cellular responses to UV radiation have received unprecedented attention. Understanding how skin cells respond to UV radiation will undoubtedly help decipher what goes wrong in a variety of clinical skin disorders including skin cancer and will facilitate the development of novel therapeutic strategies. In the past decade, studies have established that UV radiation induces multifarious signal transduction pathways, some of which lead to apoptotic cell death, while others protect against this process. In this review, we summarize some of the most recent progresses regarding the involvement of multiple signal pathways in UV radiation-induced apoptosis in skin cells, especially in keratinocytes. These pathways include pro-apoptosis components such as MAPK, AMPK, and p53 as well as pro-survival components, namely, AKT and mTORC complexes.


Subject(s)
Skin Neoplasms/prevention & control , Skin , Ultraviolet Rays/adverse effects , Adenylate Kinase/metabolism , Animals , Apoptosis/physiology , Apoptosis/radiation effects , Enzyme Activation , Humans , Mitogen-Activated Protein Kinases/metabolism , Multiprotein Complexes/metabolism , Protein Kinases/metabolism , Protein Processing, Post-Translational , Proto-Oncogene Proteins c-akt/metabolism , Reactive Oxygen Species/metabolism , Signal Transduction/physiology , Skin/pathology , Skin/radiation effects , Skin Neoplasms/epidemiology , TOR Serine-Threonine Kinases , Tumor Suppressor Protein p53/metabolism
20.
Cell Signal ; 20(10): 1830-8, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18644433

ABSTRACT

Ultraviolet radiation (UV) induces apoptosis and functional maturation in skin dendritic cells (DCs). However, the molecular mechanisms through which UV activates DCs have not been thoroughly investigated. In this study, we examined the mechanisms of activation and apoptosis of DCs after UV irradiation by focusing on epidermal growth factor receptor (EGFR). Our previous studies have demonstrated that in addition to cognate ligands, EGFR is also activated by UVB irradiation in cultured human skin keratinocytes in vitro and in human skin in vivo. We found for the first time in this study that UV also induces EGFR activation in cultured mouse skin DCs (XS 106 cell line) as well as mouse monocyte-derived dendritic cells (MoDCs). Pharmacological inhibition of EGFR tyrosine kinase significantly inhibits UV-induced ERK, p38, and JNK MAP kinases, and their effectors, transcription factors c-Fos and c-Jun. Inhibition of EGFR also suppresses UV-induced activation of PI3K/AKT/mTOR/S6K and NF-kappaB signal transduction pathways. Our data demonstrated that UV induces LKB1/AMPK pathway, also dependent on EGFR trans-activation. We further observed that MAPK, LKB1/AMPK, PI3K/AKT/mTOR/S6K as well as NF-kappaB activation are impaired in EGFR-/- cells compared to wide type MEF cells after UV radiation. Taken together, we conclude that UV induces multiple signaling pathways mediated by EGFR trans-activation leading to possible maturation, apoptosis and survival, and EGFR activation protects against UV-induced apoptosis in cultured mouse dendritic cells.


Subject(s)
Apoptosis/radiation effects , Dendritic Cells/cytology , Dendritic Cells/enzymology , ErbB Receptors/metabolism , Skin/cytology , Ultraviolet Rays , AMP-Activated Protein Kinases , Adaptor Proteins, Signal Transducing , Animals , Carrier Proteins/metabolism , Cell Cycle Proteins , Cells, Cultured , Dendritic Cells/radiation effects , Enzyme Activation/radiation effects , ErbB Receptors/genetics , Eukaryotic Initiation Factors , Humans , Mice , Mitogen-Activated Protein Kinases/metabolism , Models, Biological , Multienzyme Complexes/metabolism , NF-kappa B/metabolism , Phosphoproteins/metabolism , Protein Kinases/metabolism , Protein Serine-Threonine Kinases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Ribosomal Protein S6 Kinases/metabolism , Signal Transduction/radiation effects , Skin/enzymology , TOR Serine-Threonine Kinases , Transcriptional Activation/radiation effects
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