Regulation of colonic neuropeptide Y expression by the gut microbiome in patients with ulcerative colitis and its association with anxiety- and depression-like behavior in mice.

Patients with inflammatory bowel disease (IBD), including ulcerative colitis (UC), show an increased incidence of anxiety and depression; however, the association between UC-associated psychiatric disorders and the gut microbiota is unclear. This study aimed to examine whether gut microbiota from patients with UC can alter colonic gene expression, leading to anxiety- and depression-like behavior in mice receiving fecal microbiota transplantation (FMT). RNA sequencing transcriptome analyses revealed a difference in colonic gene expression between mice receiving FMT from patients with UC (UC-FMT mice) and those receiving FMT from healthy controls (HC-FMT mice). Gene ontology analysis revealed the downregulation of neuropeptide signaling pathways, including neuropeptide Y (NPY) expression, in the colons of UC-FMT mice. The protein levels of NPY also decreased in the colon and plasma of UC-FMT mice compared to those in HC-FMT mice. The oral administration of Enterococcus mundtii (EM), a bacterium isolated from the feces of patients with UC, reduced NPY expression in the colons of mice and induced intestinal inflammation, anxiety, and depression-like behavior. Reduced NPY protein levels were also observed in the plasma and hippocampus of EM-treated mice. Intraperitoneal administration of NPY significantly alleviated anxiety- and depressive-like behaviors induced by EM in mice. Capsular polysaccharide in EM was associated with EM-induced NPY downregulation in the colon. Analysis of Gene Expression Omnibus datasets showed markedly reduced NPY expression in the inflamed colons of patients with UC compared with that in the colons of healthy controls. In summary, EM-induced reduction in the colonic expression of NPY may be associated with a decrease in hippocampal NPY and anxiety- and depression-like behavior in mice.

Macrophages Promote Ovarian Cancer-Mesothelial Cell Adhesion by Upregulation of ITGA2 and VEGFC in Mesothelial Cells.

Ovarian cancer is a metastatic disease that frequently exhibits extensive peritoneal dissemination. Recent studies have revealed that noncancerous cells inside the tumor microenvironment, such as macrophages and mesothelial cells, may play a role in ovarian cancer metastasis. In this study, we found that human ovarian cancer cells (A2780 and SKOV3) adhered more to human mesothelial Met5A cells stimulated by macrophages (M-Met5A) in comparison to unstimulated control Met5A cells. The mRNA sequencing revealed that 94 adhesion-related genes, including FMN1, ITGA2, COL13A1, VEGFC, and NRG1, were markedly upregulated in M-Met5A cells. Knockdown of ITGA2 and VEGFC in M-Met5A cells significantly inhibited the adhesion of ovarian cancer cells. Inhibition of the JNK and Akt signaling pathways suppressed ITGA2 and VEGFC expression in M-Met5A cells as well as ovarian cancer-mesothelial cell adhesion. Furthermore, increased production of CC chemokine ligand 2 (CCL2) and CCL5 by macrophages elevated ovarian cancer-mesothelial cell adhesion. These findings imply that macrophages may play a significant role in ovarian cancer-mesothelial cell adhesion by inducing the mesothelial expression of adhesion-related genes via the JNK and Akt pathways.

Upregulation of SPI1 in Ectopic Endometrium Contributes to an Invasive Phenotype.

BACKGROUD AND AIM: Endometriosis is one of the most common gynecological diseases associated with chronic pelvic pain, infertility, and cancer. However, its molecular pathogenesis remains unclear. This study aimed to identify key genes involved in the pathogenesis of endometriosis. METHODS: Bioinformatic analyses were perfomed to identify key differentially expressed genes (DEGs), transcription factors (TFs), and functionally enriched pathways. Effect of SPI1 on migration, invasion, expression of ADH1B, MYH11, and PLN were analyzed in human endometriotic cells. RESULTS: By screening three transcriptome datasets from the GEO for overlapping DEGs between eutopic and ectopic endometria in patients with endometriosis, we found that the expression of ADH1B, MYH11, and PLN was markedly upregulated in the ectopic endometrium. Knockdown of ADH1B, MYH11, and PLN significantly inhibited the migration and invasion of human endometriotic 12Z cells. Additionally, gene set enrichment analysis revealed that epithelial-mesenchymal transition gene signature was positively correlated with ADH1B, MYH11, and PLN expression. Notably, the TF SPI1 was found to regulate the expression of these three genes in the endometriotic tissues and 12TZ cells. Moreover, SPI1 expression was associated with the invasion of endometriotic cells and was increased in the ectopic endometrium of patients with endometriosis. CONCLUSION: These data suggest that SPI1 plays a key role in the progression of endometriosis by regulating ADH1B, MYH11, and PLN expression and may therefore serve as a potential prognostic and therapeutic factor for endometriosis.

Luteolin Promotes Apoptosis of Endometriotic Cells and Inhibits the Alternative Activation of Endometriosis-Associated Macrophages.

Luteolin, a flavonoid present in several fruits, vegetables, nuts, and herbs reportedly exhibits anti-cancer and anti-inflammatory properties. However, the effect of luteolin on endometriosis, a painful condition characterized by the ectopic growth of endometrial tissue and pelvic inflammation, remains elusive. Herein, we observed that luteolin inhibited cell growth and induced apoptosis of 12Z human endometriotic cells by activating caspase-3, -8, and -9. Additionally, luteolin significantly inhibited the expression of key chemokines, C-C motif chemokine ligand 2 (CCL2) and CCL5, required for monocyte/macrophage influx at endometriotic sites. In macrophages stimulated by endometriotic cells, luteolin treatment suppressed the intracellular expression of M2 markers and endometriosis-promoting factors. Collectively, our data suggest that luteolin exerts anti-endometriotic effects by stimulating endometriotic cell apoptosis and hindering the alternative activation of macrophages.

Reduced Levels of Intestinal Neuropeptides and Neurotrophins in Neurotoxin-Induced Parkinson Disease Mouse Models.

Intestinal neuropeptides and neurotrophins as endocrine messengers play a key role in the bidirectional gut-brain interaction both in health and disease status. Their alterations in several neurological disorders have been reported, but whether a remarkable change occurs in Parkinson disease (PD) remains unexplored. In this study, we aimed to investigate the levels of 13 neuropeptides and 4 neurotrophins in the intestine of neurotoxin-induced PD mice. The PD mice were obtained by chronic injection of 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP) or MPTP/probenecid (MPTP/p). The levels of mRNA and protein expression in mouse intestines were measured by using real-time reverse transcription polymerase chain reaction and Western blotting, respectively. We found that the mRNA expression of 2 neuropeptides (cholecystokinin [CCK] and dynorphin A [Dyn A]) and 2 neurotrophins (brain-derived neurotrophic factor [BDNF] and neurotrophin-5) was significantly decreased in the colon of MPTP group compared to the vehicle-treated group. The protein levels of CCK, Dyn A, and BDNF were reduced in the colon of MPTP- or MPTP/p-treated mice compared to those of the vehicle-treated group. These data suggest that the intestinal expression of CCK, Dyn A, and BDNF was significantly reduced in PD animal models, and may play a role in the gut-brain axis in PD.

Iron-Storage Protein Ferritin Is Upregulated in Endometriosis and Iron Overload Contributes to a Migratory Phenotype.

High levels of iron in the peritoneal cavity during menstruation have been implicated in the pathogenesis of endometriosis. However, whether iron directly affects the growth or migration of human endometriotic cells is poorly understood. This study demonstrated the presence of increased levels of the iron storage protein, ferritin, in the endometriotic tissues of patients with endometriosis. Furthermore, iron treatment stimulated the migration and epithelial-mesenchymal transition (EMT), but not growth, of 12Z human endometriotic cells. The expression of matrix metalloproteinase (MMP)-2/-9 was markedly increased through iron treatment in 12Z cells. Interestingly, intracellular reactive oxygen species (ROS) levels were significantly increased by iron in 12Z cells, and N-acetyl-L-cysteine significantly reduced iron-induced migration and MMP-2/-9 expression. Additionally, iron stimulated the activation of the NFκB pathway, and the activation was associated with iron-induced migration and MMP-2/-9 expression in 12Z cells. Moreover, iron markedly increased EMT and MMP-2/-9 expression in endometriotic lesions in an endometriosis mouse model. Taken together, these results suggest that iron may contribute to the migration abilities of human endometriotic cells via MMP expression through the ROS-NFκB pathway.

Curcumin induces expression of 15-hydroxyprostaglandin dehydrogenase in gastric mucosal cells and mouse stomach in vivo: AP-1 as a potential target.

15-Hydroxyprostaglandin dehydrogenase (15-PGDH) catalyzes the conversion of oncogenic prostaglandin E2 to non-tumerigenic 15-keto prostaglandin E2. In the present study, we found that curcumin, a yellow coloring agent present in the rhizome of Curcuma longa Linn (Zingiberaceae), induced expression of 15-PGDH at the both transcriptional and translational levels in normal rat gastric mucosal cells. By using deletion constructs of 15-PGDH promoter, we were able to demonstrate that activator protein-1 (AP-1) is the principal transcription factor responsible for regulating curcumin-induced 15-PGDH expression. Curcumin enhanced the expression of c-Jun and c-Fos that are functional subunits of AP-1, in the nuclear fraction of cells. Silencing of c-Jun suppressed curcumin-induced expression of 15-PGDH. Moreover, the chromatin immunoprecipitation assay revealed curcumin-induced binding of c-Jun to the AP-1 consensus sequence present in the 15-PGDH promoter. Curcumin increased phosphorylation of ERK1/2 and JNK, and pharmacologic inhibition of these kinases abrogated the curcumin-induced phosphorylation of c-Jun and 15-PGDH expression. In contrast, tetrahydrocurcumin which lacks the α,ß-unsaturated carbonyl group failed to induce 15-PGDH expression, suggesting that the electrophilic carbonyl group of curcumin is essential for its induction of 15-PGDH expression. Curcumin restored the expression of 15-PGDH which is down-regulated by Helicobacter pylori through suppression of DNA methyltransferase 1. In addition, oral administration of curcumin increased the expression of 15-PGDH and its regulators such as p-ERK1/2, p-JNK, and c-Jun in the mouse stomach. Taken together, these findings suggest that curcumin-induced upregulation of 15-PGDH may contribute to chemopreventive effects of this phytochemical on inflammation-associated gastric carcinogenesis.

Effect of Dehydrocostus Lactone Isolated from the Roots of Aucklandia lappa on the Apoptosis of Endometriotic Cells and the Alternative Activation of Endometriosis-Associated Macrophages.

The roots of Aucklandia lappa have been used in traditional medicine in Asia to treat inflammation and diseases associated with pain, including endometriosis. The aim of this study was to investigate the anti-endometriotic effect of dehydrocostus lactone, an active compound in A. lappa roots, using human endometriotic cells and macrophages stimulated by these cells. Dehydrocostus lactone induced apoptotic cell death in 12Z human endometriotic cells. Dehydrocostus lactone stimulated the activation of caspase-3, -8, and -9, while caspase inhibitors significantly reversed the dehydrocostus lactone-induced cell death in 12Z cells. In addition, dehydrocostus lactone decreased the production of PGE2 and neurotrophins (BDNF, NGF, NT3, and NT4/5), which are regarded as endometriosis-associated pain factors in human endometriotic cells. Moreover, dehydrocostus lactone inhibited the expression of M2 markers (CD206, and Trem-2), IL-10, VEGF, and MMP-2/-9 in endometriosis-associated macrophages (EAMs). Furthermore, dehydrocostus lactone inhibited the Akt and NFκB pathways in both endometriotic cells and EAMs. Taken together, our findings suggest that dehydrocostus lactone, an active compound of A, lappa, has anti-endometriotic activities via induction of apoptosis and downregulation of pain factors in endometriotic cells and inhibition of the alternative activation of EAMs.

Hepatocyte nuclear factor-1 beta protects endometriotic cells against apoptotic cell death by up-regulating the expression of antiapoptotic genes†.

The overexpression of hepatocyte nuclear factor-1 beta (HNF1ß) in endometriotic lesion has been demonstrated. However, the role of HNF1ß in endometriosis remains largely unknown. Human endometriotic 12Z cells showed higher level of HNF1ß when compared with normal endometrial HES cells. In human endometriotic 12Z cells, HNF1ß knockdown increased susceptibility to apoptotic cell death by oxidative stress, while HNF1ß overexpression suppressed apoptosis. In addition, HNF1ß knockdown and overexpression significantly decreased and increased, respectively, the expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)-dependent antiapoptotic genes. Knockdown of the antiapoptotic genes significantly reduced the HNF1ß-induced resistance against oxidative stress in 12Z cells. Furthermore, HNF1ß regulated the transcriptional activity of NF-κB, and an NF-κB inhibitor suppressed the HNF1ß-enhanced NF-κB-dependent antiapoptotic gene expression and the resistance of the 12Z cells against cell death. Taken together, these data suggest that HNF1ß overexpression may protect endometriotic cells against oxidative damage by augmenting antiapoptotic gene expression.

15-Deoxy-Δ12,14-prostaglandin J2 up-regulates the expression of 15-hydroxyprostaglandin dehydrogenase through DNA methyltransferase 1 inactivation.

15-Hydroxyprostaglandin dehydrogenase (15-PGDH) is the key enzyme that catalyses the conversion of prostaglandin E2 to a keto metabolite. The expression of 15-PGDH is ubiquitously repressed in various human malignancies. However, the molecular mechanisms underlying down-regulation of 15-PGDH expression remain largely unknown. 15-Deoxy-△12,14-prostaglandin J2 (15d-PGJ2), an endogenous ligand of peroxisome proliferator-activated receptor γ, has been reported to have anti-inflammatory and anticarcinogenic activities. In the present study, we have found that 15d-PGJ2 induces expression and catalytic activity of 15-PGDH in human breast cancer (MDA-MB-231) cells. 15d-PGJ2 decreased the level of CpG methylation in the 15-PGDH promoter in MDA-MB-231 cells as determined by the bisulphite genome sequencing and methyl-specific PCR. 15d-PGJ2 inhibited the catalytic activity of methyltransferase 1 (DNMT1) but did not influence its expression. Biotinylated 15d-PGJ2 directly interacted with DNMT1 and reduced its catalytic activity. Chromatin-immunoprecipitation analysis revealed that 15d-PGJ2 significantly attenuated DNMT1 binding to the activator protein-1 transcription factor present in the 15-PGDH promoter region. A nonelectrophilic analogue 9,10-dihydro-15d-PGJ2 failed to suppress the methylation of CpG islands present in 15-PGDH promoter and did not affect both DNMT1 activity and 15-PGDH expression. These findings suggest that the α,ß-unsaturated carbonyl group present in 15d-PGJ2 is essential for its inactivation on DNMT1 and expression of 15-PGDH. In conclusion, 15d-PGJ2 plays as a hypomethylating agent through direct interaction with DNMT1 and consequently suppresses DNMT1-mediated hypermethylation of 15-PGDH promoter, leading to up-regulation of 15-PGDH expression.

Anticancer Activity of Gukulenin A Isolated from the Marine Sponge Phorbas gukhulensis In Vitro and In Vivo.

Gukulenin A is a bis-tropolone tetraterpenoid isolated from the marine sponge Phorbas gukhulensis. In this study, we examined the anticancer activities of gukulenin A in ovarian cancer cell lines (A2780, SKOV3, OVCAR-3, and TOV-21G) and in an ovarian cancer mouse model generated by injecting A2780 cells. We found that gukulenin A suppressed tumor growth in A2780-bearing mice. Gukulenin A markedly inhibited cell viability in four ovarian cancer cell lines, including the A2780 cell line. Gukulenin A treatment increased the fraction of cells accumulated at the sub G1 phase in a dose-dependent manner and the population of annexin V-positive cells, suggesting that gukulenin A induces apoptotic cell death in ovarian cancer cells. In addition, gukulenin A triggered the activation of caspase-3, -8, and -9, and caspase inhibitors attenuated gukulenin A-induced A2780 cell death. The results suggest that gukulenin A may be a potential therapeutic agent for ovarian cancer.

Interleukin 6 secretion from alternatively activated macrophages promotes the migration of endometriotic epithelial cells.

Accumulating evidence has suggested an interaction between endometriotic cells and macrophages in the endometriotic microenvironment and the potential role of this interaction in the pathogenesis of endometriosis. However, how endometriotic cells communicate with macrophages to influence their function is poorly understood. In the present study, we found that the mRNA expression and production of CC chemokine ligand 2 (CCL2) were much higher in human endometriotic epithelial cells (11Z and 12Z) than those in human endometrial epithelial cells (HES). The inhibition of CCL2 action using neutralizing antibodies substantially suppressed macrophage migration induced by endometriotic epithelial cells. The endometriosis-associated macrophages (EAMs), which are the macrophages that are stimulated by the conditioned medium (CM) of human endometriotic cells, highly expressed the M2 phenotype markers (MRC1 and TREM2). In addition, the CM of EAMs significantly increased cell migration in 12Z cells, but no significant change was observed in cell growth. RT-PCR and antibody array analyses revealed that EAMs highly express and produce interleukin (IL) 6 compared to macrophages stimulated by the CM of HES cells. Moreover, the EAM-CM-induced migration and MMP2/9 expression in endometriotic cells were significantly attenuated by IL6 signaling inhibition. These results suggest a reciprocal activation of macrophages and endometriotic cells via the soluble factors CCL2 and IL6, which may contribute to the development of endometriosis.

Effect of Kumatakenin Isolated From Cloves on the Apoptosis of Cancer Cells and the Alternative Activation of Tumor-Associated Macrophages.

The flower bud of Syzygium aromaticum (clove) has been used for centuries as a spice and herbal medicine. The biological activities of kumatakenin, a flavonoid that has recently been isolated from cloves, are poorly characterized. In the present study, the anticancer effects of kumatakenin in human ovarian cancer cells and tumor-associated macrophages (TAMs) were investigated. We found that kumatakenin exhibited significant cytotoxic activity in human ovarian cancer cells, SKOV3 and A2780. A propidium iodide and Annexin V-FITC staining assay showed that kumatakenin induces apoptosis in ovarian cancer cells. Kumatakenin treatment increased the activity of caspase-3, -8, and -9, and caspase inhibitors attenuated kumatakenin-induced SKOV3 cell death. In addition, kumatakenin was found to reduce the expressions of MCP-1 and RANTES, which are major determinants of macrophage recruitment at tumor sites in ovarian cancer cells. Moreover, kumatakenin inhibited the expression of M2 markers and cancer-promoting factors, including IL-10, MMP-2/-9, and VEGF, in macrophages stimulated by the ovarian cancer cells. In conclusion, these results suggest that kumatakenin shows anticancer activities by inducing apoptosis of ovarian cancer cells and inhibiting the alternative activation of TAM.

Anti-Endometriotic Effects of Pueraria Flower Extract in Human Endometriotic Cells and Mice.

Pueraria flowers have been used as a vegetable and an ingredient for tea and jelly. In this study, we investigated the effects of Pueraria flower extract (PFE) on endometriosis, a common gynaecological disease characterised by local sterile inflammation of peritoneal cavity. PFE suppressed the adhesion of human endometriotic cells 11Z and 12Z to human mesothelial Met5A cells. In addition, PFE significantly inhibited the migration of 11Z and 12Z cells as shown by woundhealing and transwell migration assays. PFE reduced the protein and mRNA levels of matrix metalloproteinase (MMP)-2 and MMP-9 in endometriotic cells. Moreover, extracellular signalregulated kinase (ERK)1/2 was activated by PFE treatment, and an ERK1/2 inhibitor, PD98059, significantly inhibited PFE-inhibited cell migration in endometriotic cells. Furthermore, PFE significantly suppressed endometriotic lesion formation in a mouse model. These data suggest that Pueraria flower is a potential anti-endometriotic agent for the inhibition of endometriotic cell adhesion, migration, and MMP expression.

A new acetophenone glycoside from the flower buds of Syzygium aromaticum (cloves).

A new acetophenone, 2,4,6-trihydroxy-3-methylacetophenone-2-O-ß-d-glucoside (1), together with 21 known compounds; one acetophenone (2), four chromone glycosides (3-6), six phenylpropanoids (7-12), six sesquiterpenoids (13-18), two triterpenoids (19 and 20), one sterol (21), and one tannin (22) were isolated from the flower buds of Syzygium aromaticum (cloves). The structure of the new compound 1 was determined by spectroscopic analyses including 1D-, 2D-NMR and HRMS interpretation. Among the isolates, one acetophenone (2), three phenylpropanoids (10-12), and one sesquiterpenoid (13) were isolated from the flower buds of S. aromaticum for the first time in this study. All the isolates (1-22) were evaluated for their cytotoxicity against human ovarian cancer cells (A2780) using MTT assays. Some of the isolates (5, 6, 9, 15, 17, 19, 20, and 21) showed either moderate or weak cytotoxicity on A2780 cells.

New Flavonol Glucuronides from the Flower Buds of Syzygium aromaticum (Clove).

Repeated chromatography of the EtOAc-soluble fraction from the 70% EtOH extract of the flower buds of Syzygium aromaticum (clove) led to the isolation and characterization of four new flavonol glucuronides, rhamnetin-3-O-ß-d-glucuronide (1), rhamnazin-3-O-ß-d-glucuronide (2), rhamnazin-3-O-ß-d-glucuronide-6″-methyl ester (3), and rhamnocitrin-3-O-ß-d-glucuronide-6″-methyl ester (4), together with 15 flavonoids (5-19) having previously known chemical structures. The structures of the new compounds 1-4 were determined by interpretation of spectroscopic data, particularly by 1D- and 2D-NMR studies. Six flavonoids (6, 7, 9, 14, 18, and 19) were isolated from the flower buds of S. aromaticum for the first time in this study. The flavonoids were examined for their cytotoxicity against human ovarian cancer cells (A2780) using MTT assays. Among the isolates, pachypodol (19) showed the most potent cytotoxicity on A2780 cells with an IC50 value of 8.02 µM.

Eclalbasaponin II induces autophagic and apoptotic cell death in human ovarian cancer cells.

Triterpenoids echinocystic acid and its glycosides, isolated from several Eclipta prostrata, have been reported to possess various biological activities such as anti-inflammatory, anti-bacterial, and anti-diabetic activity. However, the cytotoxicity of the triterpenoids in human cancer cells and their molecular mechanism of action are poorly understood. In the present study, we found that eclalbasaponin II with one glucose moiety has potent cytotoxicity in three ovarian cancer cells and two endometrial cancer cells compared to an aglycone echinocystic acid and eclalbasaponin I with two glucose moiety. Eclalbasaponin II treatment dose-dependently increased sub G1 population. Annexin V staining revealed that eclalbasaponin II induced apoptosis in SKOV3 and A2780 ovarian cancer cells. In addition, eclalbasaponin II-induced cell death was associated with characteristics of autophagy; an increase in acidic vesicular organelle content and elevation of the levels of LC3-II. Interestingly, autophagy inhibitor BaF1 suppressed the eclalbasaponin II-induced apoptosis. Moreover, eclalbasaponin II activated JNK and p38 signaling and inhibited the mTOR signaling. We further demonstrated that pre-treatment with a JNK and p38 inhibitor and mTOR activator attenuated the eclalbasaponin II-induced autophagy. This suggests that eclalbasaponin II induces apoptotic and autophagic cell death through the regulation of JNK, p38, and mTOR signaling in human ovarian cancer cells.

Helicobacter pylori Activates IL-6-STAT3 Signaling in Human Gastric Cancer Cells: Potential Roles for Reactive Oxygen Species.

BACKGROUND: Recent studies have shown that Helicobacter pylori (H. pylori) activates signal transducer and activator of transcription 3 (STAT3) that plays an important role in gastric carcinogenesis. However, the molecular mechanism underlying H. pylori-mediated STAT3 activation is still not fully understood. In this study, we investigated H. pylori-induced activation of STAT3 signaling in AGS human gastric cancer cells and the underlying mechanism. MATERIALS AND METHODS: AGS cells were cocultured with H. pylori, and STAT3 activation was assessed by Western blot analysis, electrophoretic mobility shift assay and immunocytochemistry. To demonstrate the involvement of reactive oxygen species (ROS) in H. pylori-activated STAT3 signaling, the antioxidant N-acetylcysteine was utilized. The expression and production of interleukin-6 (IL-6) were measured by reverse-transcription polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA), respectively. The interaction between IL-6 and IL-6 receptor (IL-6R) was determined by the immunoprecipitation assay. RESULTS: H. pylori activates STAT3 as evidenced by increases in phosphorylation on Tyr(705) , nuclear localization, DNA binding and transcriptional activity of this transcription factor. The nuclear translocation of STAT3 was also observed in H. pylori-inoculated mouse stomach. In the subsequent study, we found that H. pylori-induced STAT3 phosphorylation was dependent on IL-6. Notably, the increased IL-6 expression and the IL-6 and IL-6R binding were mediated by ROS produced as a consequence of H. pylori infection. CONCLUSIONS: H. pylori-induced STAT3 activation is mediated, at least in part, through ROS-induced upregulation of IL-6 expression. These findings provide a novel molecular mechanism responsible for H. pylori-induced gastritis and gastric carcinogenesis.

Protective Effect of Brown Alga Phlorotannins against Hyper-inflammatory Responses in Lipopolysaccharide-Induced Sepsis Models.

Brown algae have been recognized as a food ingredient and health food supplement in Japan and Korea, and phlorotannins are unique marine phenol compounds produced exclusively by brown algae. Sepsis is a whole-body inflammatory condition with a mortality rate of 30-40%. Here, we investigated the effects of a phlorotannin-rich extract of the edible brown alga Ecklonia cava against hyper-inflammatory response in LPS-induced septic shock mouse model. E. cava extract significantly increased the survival rate and attenuated liver and kidney damage in the mice. In addition, E. cava attenuated serum levels of NO, PGE2, and HMGB-1. In macrophages, treatment with E. cava extract down-regulated iNOS, COX-2, TNF-α, IL-6, and HMGB-1. In addition, E. cava suppressed the NIK/TAK1/IKK/IκB/NFκB pathway. Moreover, E. cava increased Nrf2 and HO-1 expression. HO-1 knockdown using siRNA restored the extract-suppressed NO and PGE2 production. Dieckol, a major compound in the extract, reduced mortality, tissue toxicity, and serum levels of the inflammatory factors in septic mice. These data suggest that brown algae phlorotannins suppress septic shock through negative regulation of pro-inflammatory factors via the NIK/TAK1/IKK/IκB/NFκB and Nrf2/HO-1 pathways.

Helicobacter pylori Induces Hypermethylation of CpG Islands Through Upregulation of DNA Methyltransferase: Possible Involvement of Reactive Oxygen/Nitrogen Species.

Helicobacter pylori infection has been considered to be one of the major factors implicated in etiology of gastric cancer. Aberrant DNA methylation accounts for epigenetic modifications induced by H. pylori. H. pylori-induced hypermethylation has been linked to enhancement of the rates of metastasis and recurrence in gastric cancer patients. H. pylori-induced gene hypermethylation has been known to be associated with inflammation. However, the molecular mechanisms underlying H. pylori-induced hypermethylation remain largely unknown. This review highlights possible involvement of reactive oxygen/nitrogen species in H. pylori-induced hypermethylation and gastric carcinogenesis.