Abstract Background Skin is uniquely vulnerable to damage caused by reactive oxygen species (ROS), which are most commonly produced in response to ultraviolet (UV) light. ROS generated at injury ...sites play an important role in modulating the inflammatory response. Besides inhibiting Rac, 7,8-dihydro-8-oxo-2′-deoxyguanosine (8-oxo-dG) has also shown notable antioxidant action. Objective We tested whether 8-oxo-dG could protect skin from UVB-induced damage by scavenging ROS. Methods HaCaT cells and hairless mice were irradiated with 15 and 180 mJ/cm2 narrow-spectrum UVB, respectively. ROS generation was detected through incubation with DCFDA and confocal microscopy. Western blot analyses and immunohistochemistry were performed to verify the activities of ERK, JNK, p38, ATF-2, and c-Jun, and the expression of matrix metalloproteinases (MMPs), in UVB-irradiated HaCaT cells and murine skin. Hydrogen peroxide production and protein carbonyl concentrations were measured in UVB-damaged mouse skin. MMP-1 and MMP-9 expression in UVB-irradiated HaCaT cells was measured by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Results In UVB-irradiated HaCaT cells, 8-oxo-dG inhibited ROS production, subsequent activation of mitogen-activated protein kinase (MAPK), ATF-2, and c-Jun, and MMP expression. It also prevented UV-induced skin reactions in hairless mice, inhibiting the increase in protein carbonyl content, activation of MAPKs, ATF-2, and c-Jun, the increases in MMP-9 and -13 expression, and epidermal hyperplasia. Conclusion 8-oxo-dG can be considered an endogenous antioxidant and its potent antioxidant activity might be a beneficial property that could be exploited to protect skin from ROS-associated photodamage.
The transcription factor signal transducers and activators of transcription 3 (STAT3) can promote cancer metastasis, but its underlying regulatory mechanisms in gastric cancer cell invasiveness still ...remain obscure. We investigated the relationship between STAT3 and glycogen synthase kinase‐3β (GSK‐3β) and its significance in metastatic potential in gastric cancer cells. Immunohistochemical tissue array analysis of 267 human gastric carcinoma specimens showed that the expressions of active forms of STAT3 (pSTAT3) and GSK‐3β (pGSK‐3β) were found in 68 (25%) and 124 (46%) of 267 gastric cancer cases, respectively, showing a positive correlation (p < 0.001). Cell culture experiments using gastric cancer cell lines SNU‐638 and SNU‐668 revealed that STAT3 suppression did not affect pGSK‐3β expression, whereas GSK‐3β inhibition reduced pSTAT3 expression. With respect to metastatic potential in gastric cancer cells, both STAT3 suppression and GSK‐3β inhibition decreased cell migration, invasion, and mesenchymal marker (Snail, Vimentin, and MMP9) expression. Moreover, the inhibitory effects of STAT3 and GSK‐3β on cell migration were synergistic. These results demonstrated that STAT3 and GSK‐3β are positively associated and synergistically contribute to metastatic potential in gastric cancer cells. Thus, dual use of STAT3 and GSK‐3β inhibitors may enhance the efficacy of the anti‐metastatic treatment of gastric cancer.
Zeolite 4A, synthetic silicate, has been shown to exhibit diverse biological activities such as anti-cancer and anti-oxidant activity. In the present study, we report that the zeolite 4A may improve ...skin-whitening. We found that zeolite 4A inhibited melanin production in a dose-dependent manner, which has not cytotoxicity. Zeolite 4A also inhibited alpha-melanocyte-stimulating hormone (α-MSH)-induced melanin synthesis in B16F10 cells. Interestingly, zeolite 4A decreased α-MSH-induced tyrosinase activity in B16F10 cells, which did not inhibit tyrosinase activity under cell-free conditions. The results of this study indicate that zeolite 4A may reduce pigmentation by way of an indirect nonenzymatic mechanism. We also found that zeolite 4A decreased α-MSH-induced microphthalmia-associated transcription factor (MITF) and tyrosinase expression and that zeolite 4A induced the activation of extracellular signal-regulated kinase (ERK). These results suggest that the depigmenting effect of zeolite 4A may result from the down-regulation of MITF and tyrosinase expression by increasing ERK activity. The results thus provide evidence that zeolite 4A can be used as a potential skin-whitening agent.
Recently, we observed that 8-hydroxyguanosine triphosphate and 8-hydroxy-2′-deoxyguanosine (oh
8dG) inactivate Rac and consequently down-regulate the Rac-linked NADPH oxidase, iNOS, and Cox2. Based ...on these observations, we tested whether oh
8dG has anti-inflammatory activity in vivo in lipopolysaccharide (LPS)-treated mice. LPS (1 mg/kg, ip)-treated mice exhibit marked inflammatory responses, including increases in proinflammatory cytokines (TNF-α, IL-6, IL-18, and IL-12p70) in serum and infiltration of neutrophils, increased translocation of NF-κB p50 from the cytosol to the nucleus, and phosphorylation of c-Jun in lung tissues. Mice were pretreated with oh
8dG (up to 60 mg/kg, ip) 4 h before LPS injection, and this pretreatment dose-dependently inhibited the inflammatory responses; the inhibitions observed with 60 mg/kg oh
8dG were statistically significant. At the same time, oh
8dG pretreatment inactivated Rac in lung tissues. Oh
8dG pretreatment (50 mg/kg, ip) also significantly protected against LPS-induced septic death. Furthermore, oh
8dG was more effective than acetyl salicylic acid in inhibiting these inflammatory responses. 8-Hydroxyguanosine also had some effect but was much weaker than oh
8dG. The effects of normal nucleosides (dG, G, and A) were negligible or not significant. These results support an anti-inflammatory activity for oh
8dG, which could be ascribed to its Rac-inactivating action.
Ornithine decarboxylase 1 (ODC1), a metabolic enzyme critically involved in the polyamine biosynthesis, is commonly upregulated in hepatocellular carcinoma (HCC). Despite its altered expression in ...human HCC tissues, the molecular mechanism by which ODC1 alters the course of HCC progression and functions in HCC cell survival is unknown. Here we identified that silencing of ODC1 expression with small interfering (si) RNA causes inhibition of HCC cell growth through blockade of cell cycle progression and induction of apoptosis. Next, to obtain insights into the molecular changes in response to ODC1 knockdown, global changes in gene expression were examined using RNA sequencing. It revealed that 119 genes show same directional regulation (76 up- and 43 down-regulated) in both Huh1 and Huh7 cells and were considered as a common ODC1 knockdown signature. Particularly, we found through a network analysis that KLF2, which is known to inhibit PPARγ expression and adipogenesis, was commonly up-regulated. Subsequent Western blotting affirmed that the downregulation of ODC1 was accompanied by a decrease in the levels of PPARγ as well as of PARP-1, cyclin E1 and pro-caspase 9 delaying cell cycle progression and accelerating apoptotic signaling. Following the down-regulation of PPARγ expression, ODC1 silencing resulted in a strong inhibition in the expression of important regulators of glucose transport and lipid biogenesis, and caused a marked decrease in lipid droplet accumulation. In addition, ODC1 silencing significantly inhibited the growth of human HCC xenografts in nude mice. These findings indicate that the function of ODC1 is correlated with HCC lipogenesis and suggest that targeting ODC1 could be an attractive option for molecular therapy of HCC.
•ODC1 silencing inhibits HCC cell growth.•ODC1 silencing delays cell cycle progression and induces apoptosis in HCC cells.•ODC1 silencing decreases the expression level of PPARγ.•ODC1 silencing inhibits PPARγ-mediated glucose transport and lipid biogenesis.•ODC1 silencing inhibits the growth of human HCC xenografts in nude mice.
To investigate the obstetrical, neonatal, and long-term outcomes of in vitro maturation (IVM) compared with conventional in vitro fertilization (IVF) in women with polycystic ovarian syndrome (PCOS).
...Matched retrospective case-control study.
University fertility clinic.
One hundred eighty-four patients undergoing IVM were compared with 366 patients undergoing conventional IVF. All had PCOS and were matched for patient age, gestational age at birth, and the number of fetuses.
None.
Obstetrics, neonatal outcomes, and childhood medical problems and development.
Women's mean age at oocytes retrieval was 32.6 ± 2.9 years. Children's mean age was 7.5 ± 2.3 years. There were no differences in the frequency of obstetrical and neonatal outcomes between the two groups. No difference was found in birth weights between the two groups. The incidence of congenital anomalies was similar between the groups (4.3% in IVM group vs. 4.1% in IVF group). No significant difference was observed between the two groups in the frequency and duration of hospitalization during childhood. Growth developmental status of both groups was within normal range.
In a matched setting between IVM and IVF babies born from women with PCOS, no significant increased risk associated with IVM was been identified after a mean follow-up of 7.5 years.
Although histone acetylation is important for epigenetic gene transcription, histone acetylation regulation by extracellular
cues has rarely been evidenced. Here, we examined whether and how histone ...acetylation is regulated by cell adhesion-mediated
signaling. Gastric carcinoma cells in suspension showed a higher histone acetylation, compared with fibronectin-adherent cells.
This difference was supported by a decreased histone deacetylases activity. Furthermore, trichostatin A (TSA)-mediated histone
acetylation was significantly increased only in suspended, but not in fibronectin-adherent, cells. Pharmacological inhibition
of intracellular contractility-related myosin light chain kinase or RhoA-kinase (ROCK) or expression of ROCK1 small interfering
RNA, dominant negative RhoA, or active Rac1 decreased basal and TSA-mediated histone H3 acetylationsinsuspendedcells,whereasinhibitionofcalmodulin-dependent
protein kinase II or transient overexpression of wild type myosin light chain kinase enhanced the acetylations. Meanwhile,
chromatin immunoprecipitation showed higher basal and TSA-enhanced associations of ROCK1 promoter regions with Lys 9 -acetylated histone 3 in suspended cells than in fibronectin-adherent cells and expression of ROCK1 was higher and further
increased by TSA treatment in suspension. In addition, phosphorylation of myosin light chain was further increased by TSA
in suspension and higher in anchorage-independent cells over adherently growing cells, indicating an inverse relationship
between ROCK1 expression-mediated contractility and cell adhesion abilities. Cell adhesion analysis showed that pharmacological
activation of intracellular contractility-related signaling activities decreased cell adhesion abilities, whereas inhibition
of them increased the adhesion. Taken together, these observations suggest that cell adhesion-related signal transduction
regulates histone acetylation, presumably through a close functional linkage between intracellular contractility and histone
deacetylases activity/histone acetylation.
•8-Oxo-dG ameliorates hyperglycemia and hyperinsulinemia in obese mice.•8-Oxo-dG improves lipid profiles and the fatty liver changes in obese mice.•8-Oxo-dG suppresses systemic inflammation and ...enhances adiponectin in obese mice.•8-Oxo-dG inhibits Rac1 activation in white adipose tissue from obese mice.
Metabolic syndrome describes a group of clinical features that together increase the incidence of coronary artery disease, stroke and type 2 diabetes. Insulin resistance is a major risk factor for developing metabolic syndrome. A chronic state of inflammation accompanies the accumulation of surplus lipids in adipose and liver tissue, frequently involved in insulin resistance. 8-Oxo-2′-deoxyguanosine (8-Oxo-dG) is a potent anti-inflammatory agent that inactivates both Rac1 and Rac2 which are critical to initiating the inflammatory responses in various cell types, including macrophages. In this study, we explored whether 8-Oxo-dG suppressed a series of systemic inflammatory cascades, resulting in the amelioration of typical features of metabolic syndrome in obese mice. The results demonstrate that 8-Oxo-dG effectively improved hyperglycemia, dyslipidemia and fatty liver changes in obese mice. The level of biochemical markers indicative of systemic inflammation were reduced in 8-Oxo-dG treated mice, whereas serum levels of adiponectin, a crucial factor associated with improved metabolic syndrome, were enhanced. Our results demonstrate that 8-Oxo-dG effectively disrupts the pathogenesis of insulin resistance and obesity-associated metabolic syndrome.
The EMT (epithelial-mesenchymal transition) is involved in fibrosis and cancer, and is regulated by different signalling pathways mediated through soluble factors, actin reorganization and ...transcription factor actions. Because the tetraspan (also called tetraspanin) TM4SF5 (transmembrane 4 L6 family member 5) is highly expressed in hepatocellular carcinoma and induces EMT, understanding how TM4SF5 expression in hepatocytes is regulated is important. We explored the mechanisms that induce TM4SF5 expression and whether impaired signalling pathways for TM4SF5 expression inhibit the acquisition of mesenchymal cell features, using human and mouse normal hepatocytes. We found that TGFβ1 (transforming growth factor β1)-mediated Smad activation caused TM4SF5 expression and EMT, and activation of the EGFR EGF (epidermal growth factor) receptor pathway. Inhibition of EGFR activity following TGFβ1 treatment abolished acquisition of EMT, suggesting a link from Smads to EGFR for TM4SF5 expression. Further, TGFβ1-mediated EGFR activation and TM4SF5 expression were abolished by EGFR suppression or extracellular EGF depletion. Smad overexpression mediated EGFR activation and TM4SF5 expression in the absence of serum, and EGFR kinase inactivation or EGF depletion abolished Smad-overexpression-induced TM4SF5 and mesenchymal cell marker expression. Inhibition of Smad, EGFR or TM4SF5 using Smad7 or small compounds also blocked TM4SF5 expression and/or EMT. These results indicate that TGFβ1- and growth factor-mediated signalling activities mediate TM4SF5 expression leading to acquisition of mesenchymal cell features, suggesting that TM4SF5 induction may be involved in the development of liver pathologies.
Using an established high-performance liquid chromatography (HPLC) method based on anion exchange chromatography, fraction collection, and electrochemical detection, the oxidative DNA damage marker ...8-hydroxy-2′-deoxyguanosine (8-OH-dG) can be analyzed rapidly and precisely in human urine samples. In addition, by ultraviolet (UV) detection, it was shown recently that it is possible to simultaneously analyze creatinine and 7-methylguanine (m
7Gua), an RNA degradation product, in urine. By adding a fluorescence detector to the HPLC system, we now report that it is also possible to detect pteridins such as neopterin and biopterin. The fluorescence detection was evaluated in detail for neopterin, an immune response and tumor marker. The urinary content of neopterin, assessed by using the HPLC method, was verified with a commercial neopterin enzyme-linked immunosorbent assay (ELISA) kit as indicated by the high correlation between the two methods (
r
=
0.98). In urinary samples from 58 young healthy individuals (male and female nonsmokers, ages 19–39 years), it was found that there was no significant correlation (
r
=
−0.04) between the levels of 8-OH-dG and neopterin (as normalized to urinary creatinine levels). In contrast, in urinary samples from 60 old healthy individuals (male and female nonsmokers, ages 60–86 years), there was a significant correlation (
r
=
0.47) found between the levels of 8-OH-dG and neopterin (as normalized to urinary creatinine levels). These findings strongly indicate that the higher level of immune response that was correlating with old age contributes significantly to the higher level of oxidative damage as assessed in the form of 8-OH-dG. Using this type of HPLC system, it is possible to evaluate oxidative DNA damage and immune response simultaneously using the respective urinary markers. These data may contribute to understanding of the pathophysiology of diseases such as infections and tumor progression where both oxidative stress and immune response occur simultaneously.
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