Puerarin attenuates hepatic steatosis via G-protein-coupled estrogen receptor-mediated calcium and SIRT1 signaling pathways.

Puerarin, the major bioactive ingredient isolated from the root of Pueraria lobata (Willd.), attenuates body weight gain and reduces lipid levels in high-fat diet-induced obese mice; however, the underlying mechanism responsible for regulating lipid metabolism remains unclear. This study investigated the molecular mechanism(s) underlying the role of puerarin in regulating lipogenesis and lipolysis in human HepG2 cells. In this study, puerarin strongly inhibited the expression of fatty acid synthase (FASN) and sterol regulatory element binding protein 1c (SREBP-1c). Moreover, puerarin significantly induced the expression of adipose triglyceride lipase (ATGL), which is responsible for triacylglycerol hydrolase activity in cells. Puerarin enhanced 5' AMP-activated protein kinase (AMPK) activity, which is a central regulator of hepatic lipid metabolism. Furthermore, this AMPK activation could be mediated by sirtuin 1 (SIRT1) and calcium signaling pathways involved in G protein-coupled estrogen receptor (GPER) signaling. GPER blockage significantly reversed the effect of puerarin on lipid accumulation and the related signaling pathways. Docking studies showed that puerarin could bind in the GPER in a similar manner as GPER agonist G1. Our results suggest that puerarin can improve hepatic steatosis by activating GPER; it's signaling cascade sequentially induced calcium and SIRT1 signaling pathways. Thus, puerarin may be a potential therapeutic agent for the treatment of non-alcoholic fatty liver disease.

Effect of Porcine Whole Blood Protein Hydrolysate on Slow-Twitch Muscle Fiber Expression and Mitochondrial Biogenesis via the AMPK/SIRT1 Pathway.

Skeletal muscle is a heterogeneous tissue composed of a variety of functionally different fiber types. Slow-twitch type I muscle fibers are rich with mitochondria, and mitochondrial biogenesis promotes a shift towards more slow fibers. Leucine, a branched-chain amino acid (BCAA), regulates slow-twitch muscle fiber expression and mitochondrial function. The BCAA content is increased in porcine whole-blood protein hydrolysates (PWBPH) but the effect of PWBPH on muscle fiber type conversion is unknown. Supplementation with PWBPH (250 and 500 mg/kg for 5 weeks) increased time to exhaustion in the forced swimming test and the mass of the quadriceps femoris muscle but decreased the levels of blood markers of exercise-induced fatigue. PWBPH also promoted fast-twitch to slow-twitch muscle fiber conversion, elevated the levels of mitochondrial biogenesis markers (SIRT1, p-AMPK, PGC-1α, NRF1 and TFAM) and increased succinate dehydrogenase and malate dehydrogenase activities in ICR mice. Similarly, PWBPH induced markers of slow-twitch muscle fibers and mitochondrial biogenesis in C2C12 myotubes. Moreover, AMPK and SIRT1 inhibition blocked the PWBPH-induced muscle fiber type conversion in C2C12 myotubes. These results indicate that PWBPH enhances exercise performance by promoting slow-twitch muscle fiber expression and mitochondrial function via the AMPK/SIRT1 signaling pathway.

Influence of o,p'-DDT on MUC5AC expression via regulation of NF-κB/AP-1 activation in human lung epithelial cells.

o,p'-Dichlorodiphenyltrichloroethane (o,p'-DDT) is a representative endocrine disruptor, and exposure to o,p'-DDT may produce immune disorders and inflammation, leading to various diseases such as cancer. Chronic airway inflammation is characterized by excessive mucus secretion resulting in chronic obstructive pulmonary disease (COPD). Mucin 5AC  (MUC5AC), one of the mucus genes, plays an important role in mucus secretion and inflammation in the airways. The aim of this study was to examine the effects of o,p'-DDT on the regulation of MUC5AC expression in human lung epithelial A549 cell line. o,p'-DDT increased mRNA levels and the promoter activity of MUC5AC. Transient transfection with mutation promoter constructs of MUC5AC demonstrated that nuclear factor kappa-b (NF-κB) and activator protein 1(AP-1) response elements were essential for the consequences of o,p'-DDT on MUC5AC expression. In addition, o,p'-DDT induced phosphorylation of ERK, JNK, p38, and Akt, which are involved in the regulation of MUC5AC expression. It is noteworthy that inhibitors of NF-κB, AP-1, Akt, and MAPKs blocked enhanced o,p'-DDT-induced MUC5AC mRNA expression. Data indicate that o,p'-DDT increase in NF-κB, and AP-1 transcriptional activation-dependent MUC5AC expression is associated with stimulation of Akt and MAPK signaling pathways in A549 cells.

Effects of tobacco compound 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) on the expression of epigenetically regulated genes in lung carcinogenesis.

Cigarette smoking is a major cause of lung cancer. Although tobacco smoking-induced genotoxicity has been well established, there is apparent lack of abundance functional epigenetic effects reported On cigarette smoke-induced lung carcinogenesis. The aim of this study was to determine effects of intratracheal administration of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) utilizing target gene expression DNA methylation patterns in lung tissues of mice following twice weekly for 8 weeks treatment. An unbiased approach where genomic regions was undertaken to assess early methylation changes within mouse pulmonary tissues. A methylated-CpG island recovery assay (MIRA) was performed to map the DNA methylome in lung tissues, with the position of methylated DNA determined using a Genome Analyzer (MIRA-SEQ). Alterations in epigenetic-regulated target genes were confirmed with quantitative reverse transcription-PCR, which revealed 35 differentially hypermethylated genes including Cdkn1C, Hsf4, Hnf1a, Cdx1, and Hoxa5 and 30 differentially hypomethylated genes including Ddx4, Piwi1, Mdm2, and Pce1 in NNK-exposed lung tissue compared with controls. The main pathway of these genes for mediating biological information was analyzed using the Kyoto Encyclopedia of Genes and Genomes database. Among them, Rssf1 and Mdm2 were closely associated with NNK-induced lung carcinogenesis. Taken together, our data provide valuable resources for detecting cigarette smoke-induced lung carcinogenesis.

Impressic Acid Attenuates the Lipopolysaccharide-Induced Inflammatory Response by Activating the AMPK/GSK3ß/Nrf2 Axis in RAW264.7 Macrophages.

Inflammatory diseases are caused by excessive inflammation from pro-inflammatory mediators and cytokines produced by macrophages. The Nrf2 signaling pathway protects against inflammatory diseases by inhibiting excessive inflammation via the regulation of antioxidant enzymes, including HO-1 and NQO1. We investigated the anti-inflammatory effect of impressic acid (IPA) isolated from Acanthopanax koreanum on the lipopolysaccharide (LPS)-induced inflammation and the underlying molecular mechanisms in RAW264.7 cells. IPA attenuated the LPS-induced production of pro-inflammatory cytokines and reactive oxygen species, and the activation of the NF-κB signaling pathway. IPA also increased the protein levels of Nrf2, HO-1, and NQO1 by phosphorylating CaMKKß, AMPK, and GSK3ß. Furthermore, ML385, an Nrf2 inhibitor, reversed the inhibitory effect of IPA on LPS-induced production of pro-inflammatory cytokines in RAW264.7 cells. Therefore, IPA exerts an anti-inflammatory effect via the AMPK/GSK3ß/Nrf2 signaling pathway in macrophages. Taken together, the findings suggest that IPA has preventive potential for inflammation-related diseases.

Rutaecarpine Increases Nitric Oxide Synthesis via eNOS Phosphorylation by TRPV1-Dependent CaMKII and CaMKKß/AMPK Signaling Pathway in Human Endothelial Cells.

Rutaecarpine (RUT) is a bioactive alkaloid isolated from the fruit of Evodia rutaecarpa that exerts a cellular protective effect. However, its protective effects on endothelial cells and its mechanism of action are still unclear. In this study, we demonstrated the effects of RUT on nitric oxide (NO) synthesis via endothelial nitric oxide synthase (eNOS) phosphorylation in endothelial cells and the underlying molecular mechanisms. RUT treatment promoted NO generation by increasing eNOS phosphorylation. Additionally, RUT induced an increase in intracellular Ca2+ concentration and phosphorylation of Ca2+/calmodulin-dependent protein kinase kinase ß (CaMKKß), AMP-activated protein kinase (AMPK), and Ca2+/calmodulin-dependent kinase II (CaMKII). Inhibition of transient receptor potential vanilloid type 1 (TRPV1) attenuated RUT-induced intracellular Ca2+ concentration and phosphorylation of CaMKII, CaMKKß, AMPK, and eNOS. Treatment with KN-62 (a CaMKII inhibitor), Compound C (an AMPK inhibitor), and STO-609 (a CaMKKß inhibitor) suppressed RUT-induced eNOS phosphorylation and NO generation. Interestingly, RUT attenuated the expression of ICAM-1 and VCAM-1 induced by TNF-α and inhibited the inflammation-related NF-κB signaling pathway. Taken together, these results suggest that RUT promotes NO synthesis and eNOS phosphorylation via the Ca2+/CaMKII and CaM/CaMKKß/AMPK signaling pathways through TRPV1. These findings provide evidence that RUT prevents endothelial dysfunction and benefit cardiovascular health.

Impressic Acid Ameliorates Atopic Dermatitis-Like Skin Lesions by Inhibiting ERK1/2-Mediated Phosphorylation of NF-κB and STAT1.

Impressic acid (IPA), a lupane-type triterpenoid from Acanthopanax koreanum, has many pharmacological activities, including the attenuation of vascular endothelium dysfunction, cartilage destruction, and inflammatory diseases, but its influence on atopic dermatitis (AD)-like skin lesions is unknown. Therefore, we investigated the suppressive effect of IPA on 2,4-dinitrochlorobenzene (DNCB)-induced AD-like skin symptoms in mice and the underlying mechanisms in cells. IPA attenuated the DNCB-induced increase in the serum concentrations of IgE and thymic stromal lymphopoietin (TSLP), and in the mRNA levels of thymus and activation regulated chemokine(TARC), macrophage derived chemokine (MDC), interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-13 (IL-13), tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) in mice. Histopathological analysis showed that IPA reduced the epidermal/dermal thickness and inflammatory and mast cell infiltration of ear tissue. In addition, IPA attenuated the phosphorylation of NF-κB and IκBα, and the degradation of IκBα in ear lesions. Furthermore, IPA treatment suppressed TNF-α/IFN-γ-induced TARC expression by inhibiting the NF-κB activation in cells. Phosphorylation of extracellular signalregulated protein kinase (ERK1/2) and the signal transducer and activator of transcription 1 (STAT1), the upstream signaling proteins, was reduced by IPA treatment in HaCaT cells. In conclusion, IPA ameliorated AD-like skin symptoms by regulating cytokine and chemokine production and so has therapeutic potential for AD-like skin lesions.

Stimulatory effects of platycodin D on osteoblast differentiation.

Previous studies have suggested that platycodin D is implicated in bone biology and ameliorates osteoporosis development. Platycodin D repressed the osteoclast activity and enhanced bone mineral density in the mouse model. However, the effects of platycodin D on osteoblast differentiation have not been elucidated yet. In C3H10T1/2 cells, platycodin D upregulated osteogenic markers including alkaline phosphatase (ALP), bone sialoprotein, and collagen type 1 alpha 1, and transcription factors, such as Runx2 and osterix, subsequently enhancing the bone mineralization. In a molecular mechanism study, platycodin D induced ß-catenin nuclear accumulation by upregulating GSK3ß phosphorylation. Furthermore, platycodin D upregulated the ALP activity and enhanced the mineralization process in osteoblast cells via the sirtuin 1/ß-catenin pathways. Taken together, these results suggested that platycodin D could be an effective therapeutic compound against osteoporosis because of its regulatory effects during the osteoblast differentiation.

Impressic Acid, a Lupane-Type Triterpenoid from Acanthopanax koreanum, Attenuates TNF-α-Induced Endothelial Dysfunction via Activation of eNOS/NO Pathway.

Atherosclerosis is one of the most reported diseases worldwide, and extensive research and trials are focused on the discovery and utilizing for novel therapeutics. Nitric oxide (NO) is produced mainly by endothelial nitric oxide synthase (eNOS) and it plays a key role in regulating vascular function including systemic blood pressure and vascular inflammation in vascular endothelium. In this study hypothesized that Impressic acid (IPA), a component isolated from Acanthopanax koreanum, acts as an enhancer of eNOS activity and NO production. IPA treatment induced eNOS phosphorylation and NO production, which was correlated with eNOS phosphorylation via the activation of JNK1/2, p38 MAPK, AMPK, and CaMKII. In addition, the induction of eNOS phosphorylation by IPA was attenuated by pharmacological inhibitor of MAPKs, AMPK, and CaMKII. Finally, IPA treatment prevented the adhesion of TNF-α-induced monocytes to endothelial cells and suppressed the TNF-α-stimulated ICAM-1 expression via activation of NF-κB, while treatment with L-NAME, the NOS inhibitor, reversed the inhibitory effect of IPA on TNF-α-induced ICAM-1 expression via activation of NF-κB. Taken together, these findings show that IPA protects against TNF-α-induced vascular endothelium dysfunction through attenuation of the NF-κB pathway by activating eNOS/NO pathway in endothelial cells.

WY-14643 Regulates CYP1B1 Expression through Peroxisome Proliferator-Activated Receptor α-Mediated Signaling in Human Breast Cancer Cells.

Human cytochrome P450 1B1 (CYP1B1)-mediated biotransformation of endobiotics and xenobiotics plays an important role in the progression of human breast cancer. In this study, we investigated the effects of WY-14643, a peroxisome proliferator-activated receptor α (PPARα) agonist, on CYP1B1 expression and the related mechanism in MCF7 breast cancer cells. We performed quantitative reverse transcription-polymerase chain reaction, transient transfection, and chromatin immunoprecipitation to evaluate the effects of PPARα on peroxisome proliferator response element (PPRE)-mediated transcription. WY-14643 increased the protein and mRNA levels of CYP1B1, as well as promoter activity, in MCF-7 cells. Moreover, WY-14643 plus GW6471, a PPARα antagonist, significantly inhibited the WY-14643-mediated increase in CYP1B1 expression. PPARα knockdown by a small interfering RNA markedly suppressed the induction of CYP1B1 expression by WY-14643, suggesting that WY-14643 induces CYP1B1 expression via a PPARα-dependent mechanism. Bioinformatics analysis identified putative PPREs (-833/-813) within the promoter region of the CYP1B1 gene. Inactivation of these putative PPREs by deletion mutagenesis suppressed the WY-14643-mediated induction of CYP1B1 promoter activation. Furthermore, WY-14643 induced PPARα to assume a form capable of binding specifically to the PPRE-binding site in the CYP1B1 promoter. Our findings suggest that WY-14643 induces the expression of CYP1B1 through activation of PPARα.

Pseudoshikonin I enhances osteoblast differentiation by stimulating Runx2 and Osterix.

Pseudoshikonin I (PSI), a novel biomaterial isolated from Lithospermi radix, has been recognized as an herbal medicine for the treatment of infectious and inflammatory diseases. Bone remodeling maintains a balance through bone resorption (osteoclastogenesis) and bone formation (osteoblastogenesis). Bone formation is generally attributed to osteoblasts. However, the effects of PSI on the bone are not well known. In this study, we found that the ethanol extracts of PSI induced osteoblast differentiation by increasing the expression of bone morphogenic protein 4 (BMP 4). PSI positively regulates the transcriptional expression and osteogenic activity of osteoblast-specific transcription factors such as Runx2 and Osterix. To identify the signaling pathways that mediate PSI-induced osteoblastogenesis, we examined the effects of serine-threonine kinase inhibitors that are known regulators of Osterix and Runx2. PSI-induced upregulation of Osterix and Runx2 was suppressed by treatment with AKT and PKA inhibitors. These results suggest that PSI enhances osteoblast differentiation by stimulating Osterix and Runx2 via the AKT and PKA signaling pathways. Thus, the activation of Runx2 and Osterix is modulated by PSI, thereby demonstrating its potential as a treatment target for bone disease.

Platycodin D Inhibits Osteoclastogenesis by Repressing the NFATc1 and MAPK Signaling Pathway.

Platycodon grandiflorum root-derived saponins (Changkil saponins, CKS) are reported to have many pharmacological activities. In our latest research, CKS was proven to have a significant osteogenic effect. However, the detail molecular mechanism of CKS on osteoclastic differentiation has not been fully investigated. Administration of CKS considerably reduced OVX-induced bone loss, and ameliorated the reduction in plasma levels of alkaline phosphatase, calcium, and phosphorus observed in OVX mice. CKS also repressed the deterioration of bone trabecular microarchitecture. Interestingly, platycodin D, the most abundant and major pharmacological constituent of triterpenoid CKS, inhibited receptor activator of NF-κB ligand (RANKL)-induced activation of NF-κB, and ERK and p38 MAPK, ultimately repressing osteoclast differentiation. OVX-induced bone turnover was attenuated by CKS, possibly via repression of osteoclast differentiation by platycodin D, the active component of CKS. Platycodin D can be regarded as an antiosteoporotic candidate for treatment of osteoporosis diseases. J. Cell. Biochem. 118: 860-868, 2017. © 2016 Wiley Periodicals, Inc.

Caffeic acid phenethyl ester inhibits 3-MC-induced CYP1A1 expression through induction of hypoxia-inducible factor-1α.

Caffeic acid phenethyl ester (CAPE), a natural component of propolis, is reported to have anticarcinogenic properties, although its precise chemopreventive mechanism remains unclear. In this study, we examined the effects of CAPE on 3-methylcholanthrene (3-MC)-induced CYP1A1 expression and activities. CAPE reduced the formation of the benzo[a]pyrene-DNA adduct. Moreover, CAPE inhibited 3-MC-induced CYP1A1 activity, mRNA expression, protein level, and promoter activity. CAPE treatment also decreased 3-MC-inducible xenobiotic-response element (XRE)-linked luciferase, aryl hydrocarbons receptor (AhR) transactivation and nuclear localization. CAPE induced hypoxia inducible factor-1α (HIF-1α) protein level and HIF-1α responsible element (HRE) transcriptional activity. CAPE-mediated HIF-1α reduced 3-MC-inducible CYP1A1 protein expression. Taken together, CAPE decreases 3-MC-mediated CYP1A1 expression, and this inhibitory response is associated with inhibition of AhR and HIF-1α induction.

Endosulfan induces COX-2 expression via NADPH oxidase and the ROS, MAPK, and Akt pathways.

Endosulfan (1,4,5,6,7,7-hexachloro-8,9,10-trinorborn-5-en-2,3-ylenebismet-hylene) is correlated with endocrine disruption, reproductive, and immune dysfunctions. Recently, endosulfan was shown to have an effect on inflammatory pathways, but its influence on cyclooxygenase-2(COX-2) expression is unclear. This study investigated the effects of COX-2 and molecular mechanisms by endosulfan in murine macrophage RAW 264.7 cells. Endosulfan significantly induced COX-2 protein and mRNA levels, as well as COX-2 promoter-driven luciferase activity and the production of prostaglandin E2, a major COX-2 metabolite. Transfection experiments with several human COX-2 promoter constructs revealed that endosulfan activated NF-κB, C/EBP, AP-1, and CREB. Moreover, Akt and mitogen-activated protein kinases (MAPK) were significantly activated by endosulfan. Moreover, endosulfan increased production of the ROS and the ROS-producing NAPDH-oxidase (NOX) family oxidases, NOX2, and NOX3. Endosulfan-induced Akt/MAPK pathways and COX-2 expression were attenuated by DPI, a specific NOX inhibitor, and the ROS scavenger N-acetylcysteine. These results demonstrate that endosulfan induces COX-2 expression via NADPH oxidase, ROS, and Akt/MAPK pathways. These findings provide further insight into the signal transduction pathways involved in the inflammatory effects of endosulfan.

Saponins from the roots of Platycodon grandiflorum suppresses TGFß1-induced epithelial-mesenchymal transition via repression of PI3K/Akt, ERK1/2 and Smad2/3 pathway in human lung carcinoma A549 cells.

Transforming growth factor ß (TGFß) is a multifunctional cytokine that induces growth arrest, tissue fibrosis, and epithelial-mesenchymal transition (EMT) through activation of Smad and non-Smad signaling pathways. EMT is the differentiation switch by which polarized epithelial cells differentiate into contractile and motile mesenchymal cells. Our previous studies have shown that saponins from the roots of Platycodon grandiflorum (CKS) have antiinflammatory, antioxidant, antimetastatic, and hepatoprotective effects. In this study, we investigated the inhibitory effect of CKS on TGFß1-induced alterations characteristic of EMT in human lung carcinoma A549 cells. We found that CKS-treated cells displayed inhibited TGFß1-mediated E-cadherin downregulation and Vimentin upregulation and also retained epithelial morphology. Furthermore, TGFß1-increased Snail expression, a repressor of E-cadherin and an inducer of the EMT, was reduced by CKS. CKS inhibited TGFß1-induced phosphorylation of Akt, ERK1/2, and glycogen synthase kinase-3ß (GSK-3ß). Inhibition of PI3K/Akt and ERK1/2 also blocked TGFß1-induced GSK-3ß phosphorylation and Snail activation. Furthermore, TGFß1-increased Snail expression was reduced by selective inhibitors of Akt and ERK1/2. Moreover, CKS treatment attenuated TGFß1-induced Smad2/3 phosphorylation and upregulated Smad7 expression. These results indicate that pretreatment with the CKS inhibits the TGFß1-induced EMT through PI3K/Akt, ERK1/2, GSK-3ß and Smad2/3 in human lung carcinoma cells.

Sesamin ameliorates lipotoxicity and lipid accumulation through the activation of the estrogen receptor alpha signaling pathway.

Nonalcoholic fatty liver disease (NAFLD) has been linked to fat accumulation in the liver and lipid metabolism imbalance. Sesamin, a lignan commonly found in sesame seed oil, possesses antioxidant, anti-inflammatory, and anticancer properties. However, the precise mechanisms by which sesamin prevents hepatic steatosis are not well understood. This study aimed to explore the molecular mechanisms by which sesamin may improve lipid metabolism dysregulation. A in vitro hepatic steatosis model was established by exposing HepG2 cells to palmitate sodium. The results showed that sesamin effectively mitigated lipotoxicity and reduced reactive oxygen species production. Additionally, sesamin suppressed lipid accumulation by regulating key factors involved in lipogenesis and lipolysis, such as fatty acid synthase (FASN), sterol regulatory element-binding protein 1c (SREBP-1c), forkhead box protein O-1, and adipose triglyceride lipase. Molecular docking results indicated that sesamin could bind to estrogen receptor α (ERα) and reduce FASN and SREBP-1c expression via the Ca2+/calmodulin-dependent protein kinase kinase ß (CaMKKß)/AMP-activated protein kinase (AMPK) signaling pathway. Sesamin attenuated palmitate-induced lipotoxicity and regulated hepatic lipid metabolism in HepG2 cells by activating the ERα/CaMKKß/AMPK signaling pathway. These findings suggest that sesamin can improve lipid metabolism disorders and is a promising candidate for treating hepatic steatosis.

Upregulation of CYP1B1 by hypoxia is mediated by ERα activation in breast cancer cells.

Endocrine therapy for breast cancer often leads to drug resistance and tumor recurrence; tumor hypoxia is also associated with mortality and tumor relapse. Cytochrome P450 1B1 (CYP1B1) regulates estrogen metabolism in breast cells and is known to be overexpressed in breast cancer tissue. Although the individual association of hypoxia-induced hypoxia-inducible factor-1-alpha (HIF-1α) and CYP1B1 with tumorigenesis is well known, the association between HIF-1α and CYP1B1 leading to tumorigenesis has not been investigated. Here, we investigated the correlation between hypoxia and CYP1B1 expression in breast cancer cells for tumorigenesis-related mechanisms. Hypoxia was induced in the human breast cancer cell lines MCF-7 (Er-positive) and MDA-MB-231 (triple-negative) and the normal breast epithelial cell line MCF10A; these cell lines were then subjected to immunoblotting, transient transfection, luciferase assays, gene silencing using small interfering RNA, polymerase chain reaction analysis, chromatin immunoprecipitation, co-immunoprecipitation, and mammalian two-hybrid assays. Furthermore, immunofluorescence analysis of the tumor microarrays was performed, and the pub2015 and the Cancer Genome Atlas patient datasets were analyzed. HIF-1α expression in response to hypoxia occurred in both normal and breast cancer cells, whereas CYP1B1 was induced only in estrogen receptor α (ERα)-positive breast cancer cells under hypoxia. HIF-1α activated ERα through direct binding and in a ligand-independent manner to promote CYP1B1 expression. Therefore, we suggested the mechanism by which hypoxia and ER-positivity orchestrate breast cancer relapse.

Rutaecarpine Protects against Acetaminophen-Induced Acute Liver Injury in Mice by Activating Antioxidant Enzymes.

Rutaecarpine, an indolopyridoquinazolinone alkaloid isolated from the unripe fruit of Evodia rutaecarpa, is used to treat hypertension, postpartum hemorrhage, dysentery, and amenorrhea as a traditional medicine in Asia. We investigated the effect of rutaecarpine on acetaminophen-induced hepatotoxicity in mice. Rutaecarpine was administered orally daily for seven consecutive days, followed by intraperitoneal injection of acetaminophen in mice on day seven to induce hepatotoxicity. Rutaecarpine pretreatment significantly decreased acetaminophen-induced serum alanine aminotransferase (ALT)/aspartate aminotransferase (AST) activities and hepatic malondialdehyde content and prevented acetaminophen-induced hepatic glutathione depletion. Furthermore, CYP2E1 expression was decreased by rutaecarpine pretreatment in a dose-dependent manner. Rutaecarpine pretreatment inhibited acetaminophen-induced expression of inflammatory cytokines by inhibiting NF-κB activation by JNK1/2. Also, rutaecarpine pretreatment promoted Nrf2-mediated activation of the antioxidant enzymes GCLC, HO-1, and NQO1. This indicates that the protective effect of rutaecarpine during acetaminophen-induced acute liver injury is mediated by the activation of antioxidant enzymes. Therefore, rutaecarpine has a protective effect of APAP-induced liver damage.

G protein-coupled estrogen receptor regulates the KLF2-dependent eNOS expression by activating of Ca2+ and EGFR signaling pathway in human endothelial cells.

G protein-coupled estrogen receptor (GPER) is important for maintaining normal blood vessel function by preventing endothelial cell dysfunction. It has been reported that G-1, an agonist of GPER, increases nitric oxide (NO) production through the phosphorylation of endothelial nitric oxide synthase (eNOS). However, the effect of GPER activation on eNOS expression has not been studied. Our results show that G-1 significantly increased the expression of eNOS and Kruppel-like factor 2 (KLF2) in human endothelial EA.hy926 cells. The individual silences of KLF2 and GPER attenuated G-1-induced eNOS expression. In addition, inhibition of the Gαq and Gßγ suppressed G-1-induced the expression of eNOS and KLF2 in EA.hy926 cells. Interestingly, these effects were similar in HUVECs. Furthermore, we found that GPER-mediated Ca2+ signaling increased the phosphorylation of CaMKKß, AMPK, and CaMKIIα in the cells. The phosphorylation of histone deacetylase 5 (HDAC5) by activation of AMPK and CaMKIIα increased the expression of eNOS via transcriptional activity of KLF2. We further demonstrate that GPER activation increased the phosphorylation of Src, EGFR, ERK5, and MEF2C and consequently induced the expression of eNOS and KLF2. Meanwhile, inhibition of ERK5 and HDAC5 suppressed the expression of eNOS and KLF2 induced by G-1 in the cells. These findings suggest that GPER provides a novel mechanism for understanding the regulation of eNOS expression and is an essential therapeutic target in preventing cardiovascular-related endothelial dysfunction.

Orostachys japonicus ethanol extract inhibits 2,4-dinitrochlorobenzene-induced atopic dermatitis-like skin lesions in NC/Nga mice and TNF-α/IFN-γ-induced TARC expression in HaCaT cells.

The risk of atopic dermatitis (AD)-like skin lesions has increased due to the elevated levels of allergens worldwide. Natural-origin agents, which are effective and safe, show promise for the prevention and treatment of inflammatory conditions. Orostachys japonicus (OJ) A. Berger is an ingredient of traditional herbal medicines for fever, gingivitis, and cancer in Korea, China, and Japan. However, the effect of OJ on AD-like skin lesions is unknown. Therefore, we investigated the effect of OJ ethanol extract (OJEE) on AD-like skin symptoms in mice and cells. OJEE reduced the 2,4-dinitrochlorobenzene-induced AD severity, serum levels of IgE and TARC, and mRNA levels of TARC, TNF-α, and IL-4 in NC/Nga mice. Histopathological analysis showed that OJEE reduced the thickness of the epidermis/dermis and dermal infiltration of inflammatory cells in ear tissue. Furthermore, OJEE suppressed the TNF-α/IFN-γ-increased TARC mRNA level by inhibiting NF-κB and STAT1 activation in HaCaT cells. Taken together, our findings show that OJEE reduced the risk of AD-like skin symptoms by decreasing TARC expression via inhibiting NF-κB and STAT1 activation in skin keratinocytes and thus shows promise as an alternative therapy for AD-like skin lesions.