MeCP2 regulates activity-dependent transcriptional responses in olfactory sensory neurons.

During postnatal development, neuronal activity controls the remodeling of initially imprecise neuronal connections through the regulation of gene expression. MeCP2 binds to methylated DNA and modulates gene expression during neuronal development and MECP2 mutation causes the autistic disorder Rett syndrome. To investigate a role for MeCP2 in neuronal circuit refinement and to identify activity-dependent MeCP2 transcription regulations, we leveraged the precise organization and accessibility of olfactory sensory axons to manipulation of neuronal activity through odorant exposure in vivo. We demonstrate that olfactory sensory axons failed to develop complete convergence when Mecp2 is deficient in olfactory sensory neurons (OSNs) in an otherwise wild-type animal. Furthermore, we demonstrate that expression of selected adhesion genes was elevated in Mecp2-deficient glomeruli, while acute odor stimulation in control mice resulted in significantly reduced MeCP2 binding to these gene loci, correlating with increased expression. Thus, MeCP2 is required for both circuitry refinement and activity-dependent transcriptional responses in OSNs.

Timosaponin AIII inhibits migration and invasion of A549 human non-small-cell lung cancer cells via attenuations of MMP-2 and MMP-9 by inhibitions of ERK1/2, Src/FAK and ß-catenin signaling pathways.

Timosaponin AIII (TAIII) is a type of steroidal saponins isolated from Anemarrhena asphodeloides. It was known to improve learning and memory deficits through anti-inflammatory effects. TAIII was also reported to induce autophagy preceding mitochondria-mediated apoptosis in HeLa cancer cells and inhibit the growth of human colorectal cancer cells, thus regarded as a potential candidate for anti-cancer agent. In this study, we verified apoptosis-inducing and cell-cycle-arresting effects of TAIII in A549 human non-small-cell lung cancer (NSCLC) cells. Then, we report that TAIII suppresses migration and invasion of A549 human NSCLC cells. We propose that two matrix metalloproteinases (MMPs), MMP-2 and MMP-9, which are well known to be involved in cancer-metastasis, are attenuated by the treatment of TAIII. TAIII exerts its suppressive effects on MMP-2 and MMP-9 via inhibitions of ERK1/2, Src/FAK and ß-catenin signalings which are closely related with the regulations of MMP-2 and MMP-9.

Luteolin inhibits hyperglycemia-induced proinflammatory cytokine production and its epigenetic mechanism in human monocytes.

Hyperglycemia is a key feature in diabetes. Hyperglycemia has been implicated as a major contributor to several complications of diabetes. High glucose levels induce the release of proinflammatory cytokines. Luteolin is a flavone isolated from celery, green pepper, perilla leaf, and chamomile tea. Luteolin has been reported to possess antimutagenic, antitumorigenic, antioxidant, and anti-inflammatory properties. In this study, we investigated the effects of luteolin on proinflammatory cytokine secretion and its underlying epigenetic regulation in high-glucose-induced human monocytes. Human monocytic (THP-1) cells were cultured under controlled (14.5 mM mannitol), normoglycemic (NG, 5.5 mM glucose), or hyperglycemic (HG, 20 mM glucose) conditions, in the absence or presence of luteolin. Luteolin (3-10 µM) was added for 48 h. While hyperglycemic conditions significantly induced histone acetylation, NF-κB activation, and proinflammatory cytokine (IL-6 and TNF-α) release from THP-1 cells, luteolin suppressed NF-κB activity and cytokine release. Luteolin also significantly reduced CREB-binding protein/p300 (CBP/p300) gene expression, as well as the levels of acetylation and histone acetyltransferase (HAT) activity of the CBP/p300 protein, which is a known NF-κB coactivator. These results suggest that luteolin inhibits HG-induced cytokine production in monocytes, through epigenetic changes involving NF-κB. We therefore suggest that luteolin may be a potential candidate for the treatment and prevention of diabetes and its complications.

Sodium butyrate inhibits high glucose-induced inflammation by controlling the acetylation of NF-κB p65 in human monocytes.

BACKGROUND/OBJECTIVES: Hyperglycemia is a major cause of diabetes and diabetes-related diseases. Sodium butyrate (NaB) is a short-chain fatty acid derivative that produces dietary fiber by anaerobic bacterial fermentation in the large intestine and occurs in foods, such as Parmesan cheese and butter. Butyrate has been shown to prevent obesity, improve insulin sensitivity, and ameliorate dyslipidemia in diet-induced obese mice. Therefore, this study examined the effects and mechanism of NaB on the secretion of inflammatory cytokines induced by high glucose (HG) in THP-1 cells. MATERIALS/METHODS: THP-1 cells were used as an in vitro model for HG-induced inflammation. The cells were cultured under normal glycemic or hyperglycemic conditions with or without NaB (0-25 µM). Western blotting and quantitative polymerase chain reaction were used to evaluate the protein and mRNA levels of nuclear factor-κB (NF-κB), interleukin-6, tumor necrosis factor-α, acetylated p65, acetyl CREB-binding protein/p300 (CBP/p300), and p300 using THP-1 cells. Histone acetyltransferase (HAT), histone deacetylase (HDAC), and pro-inflammatory cytokine secretion activity were analyzed using an enzyme-linked immunosorbent assay. RESULTS: HG significantly upregulated histone acetylation, acetylation levels of p300, NF-κB activation, and inflammatory cytokine release in THP-1 cells. Conversely, the NaB treatment reduced cytokine release and NF-κB activation in HG-treated cells. It also significantly reduced p65 acetylation, CBP/p300 HAT activity, and CBP/p300 gene expression. In addition, NaB decreased the interaction of p300 in acetylated NF-κB and TNF-α. CONCLUSIONS: These results suggest that NaB suppresses HG-induced inflammatory cytokine production through HAT/HDAC regulation in monocytes. NaB has the potential for preventing and treating diabetes and its related complications.

Neuroprotective effects of hesperetin on H2O2-induced damage in neuroblastoma SH-SY5Y cells.

BACKGROUND/OBJECTIVES: Oxidative stress is a fundamental neurodegenerative disease trigger that damages and decimates nerve cells. Neurodegenerative diseases are chronic central nervous system disorders that progress and result from neuronal degradation and loss. Recent studies have extensively focused on neurodegenerative disease treatment and prevention using dietary compounds. Heseperetin is an aglycone hesperidin form with various physiological activities, such as anti-inflammation, antioxidant, and antitumor. However, few studies have considered hesperetin's neuroprotective effects and mechanisms; thus, our study investigated this in hydrogen peroxide (H2O2)-treated SH-SY5Y cells. MATERIALS/METHODS: SH-SY5Y cells were treated with H2O2 (400 µM) in hesperetin absence or presence (10-40 µM) for 24 h. Three-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assays detected cell viability, and 4',6-diamidino-2-phenylindole staining allowed us to observe nuclear morphology changes such as chromatin condensation and apoptotic nuclei. Reactive oxygen species (ROS) detection assays measured intracellular ROS production; Griess reaction assays assessed nitric oxide (NO) production. Western blotting and quantitative polymerase chain reactions quantified corresponding mRNA and proteins. RESULTS: Subsequent experiments utilized various non-toxic hesperetin concentrations, establishing that hesperetin notably decreased intracellular ROS and NO production in H2O2-treated SH-SY5Y cells (P < 0.05). Furthermore, hesperetin inhibited H2O2-induced inflammation-related gene expression, including interluekin-6, tumor necrosis factor-α, and nuclear factor kappa B (NF-κB) p65 activation. In addition, hesperetin inhibited NF-κB translocation into H2O2-treated SH-SY5Y cell nuclei and suppressed mitogen-activated protein kinase protein expression, an essential apoptotic cell death regulator. Various apoptosis hallmarks, including shrinkage and nuclear condensation in H2O2-treated cells, were suppressed dose-dependently. Additionally, hesperetin treatment down-regulated Bax/Bcl-2 expression ratios and activated AMP-activated protein kinase-mammalian target of rapamycin autophagy pathways. CONCLUSION: These results substantiate that hesperetin activates autophagy and inhibits apoptosis and inflammation. Hesperetin is a potentially potent dietary agent that reduces neurodegenerative disease onset, progression, and prevention.

Neuroprotective Effects of Zerumbone on H2O2-Induced Oxidative Injury in Human Neuroblastoma SH-SY5Y Cells.

Oxidative stress is recognized as one of the main reasons for cellular damage and neurodegenerative diseases. Zerumbone is one of the sesquiterpenoid compounds in the essential oil of Zingiber zerumbet Smith. Zerumbone exhibits various physiological activities, such as anticancer, antioxidant, and antibacterial effects. However, studies on the neuroprotective efficacy of zerumbone and the mechanism behind it are lacking. In this study, we explored the neuroprotective efficacy of zerumbone and its mechanism in hydrogen peroxide-treated human neuroblastoma SH-SY5Y cells. H2O2 treatment (400 µM) for 24 h enhanced the generation of intracellular reactive oxygen species (ROS) compared to untreated cells. By contrast, zerumbone treatment significantly suppressed the production of intracellular ROS. Zerumbone significantly inhibited H2O2-induced nitric oxide production and expression of inflammation-related genes. Moreover, zerumbone decreased H2O2-induced mitogen-activated protein kinase (MAPK) protein expression. Various hallmarks of apoptosis in H2O2-treated cells were suppressed in a dose-dependent manner through downregulation of the Bax/Bcl-2 expression ratio by zerumbone. Since activation of AMP-activated kinase (AMPK) is a promising therapeutic target for neurodegenerative diseases, we also investigated the mammalian target of rapamycin (mTOR) as part of the autophagy mechanism in H2O2-treated SH-SY5Y cells. In this study, zerumbone upregulated the expression of Sirtuin 1 (SIRT1) and p-AMPK (which were downregulated by the H2O2 treatment) and downregulated p-mTOR. Altogether, our results propose that inhibition of apoptosis and inflammation by autophagy activation plays an important neuroprotective role in H2O2-treated SH-SY5Y cells. Zerumbone may thus be a potent dietary agent that reduces the onset and progression, as well as prevents neurodegenerative diseases.

Fisetin inhibits hyperglycemia-induced proinflammatory cytokine production by epigenetic mechanisms.

Diabetes is characterized by a proinflammatory state, and several inflammatory processes have been associated with both type 1 and type 2 diabetes and the resulting complications. High glucose levels induce the release of proinflammatory cytokines. Fisetin, a flavonoid dietary ingredient found in the smoke tree (Cotinus coggygria), and is also widely distributed in fruits and vegetables. Fisetin is known to exert anti-inflammatory effects via inhibition of the NF-κB signaling pathway. In this study, we analyzed the effects of fisetin on proinflammatory cytokine secretion and epigenetic regulation, in human monocytes cultured under hyperglycemic conditions. Human monocytic (THP-1) cells were cultured under control (14.5 mmol/L mannitol), normoglycemic (NG, 5.5 mmol/L glucose), or hyperglycemic (HG, 20 mmol/L glucose) conditions, in the absence or presence of fisetin. Fisetin was added (3-10 µM) for 48 h. While the HG condition significantly induced histone acetylation, NF-κB activation, and proinflammatory cytokine (IL-6 and TNF-α) release from THP-1 cells, fisetin suppressed NF-κB activity and cytokine release. Fisetin treatment also significantly reduced CBP/p300 gene expression, as well as the levels of acetylation and HAT activity of the CBP/p300 protein, which is a known NF-κB coactivator. These results suggest that fisetin inhibits HG-induced cytokine production in monocytes, through epigenetic changes involving NF-κB. We therefore propose that fisetin supplementation be considered for diabetes prevention.

Fisetin Inhibits Osteoclast Differentiation via Downregulation of p38 and c-Fos-NFATc1 Signaling Pathways.

The prevention or therapeutic treatment of loss of bone mass is an important means of improving the quality of life for patients with disorders related to osteoclast-mediated bone loss. Fisetin, a flavonoid dietary ingredient found in the smoke tree (Continus coggygria), exhibits various biological activities, but its effect on osteoclast differentiation is unknown. In this study, fisetin dose-dependently inhibited the RANKL-induced osteoclast differentiation with downregulation of the activity or expression of p38, c-Fos, and NFATc1 signaling molecules. The p38/c-Fos/NFATc1-regulated expression of genes required for cell fusion and bone resorption, such as DC-STAMP and cathepsin K, was also inhibited by fisetin. Considering the rescue of fisetin's inhibitory action by NFATc1 over-expression, the cascade of p38-c-Fos-NFATc1 could be strongly involved in the inhibitory effect of fisetin on osteoclast differentiation. Furthermore, fisetin inhibited the bone-resorbing activity of mature osteoclasts. In conclusion, fisetin may be of use in the treatment of osteoclast-related disorders, including osteoporosis.

Zerumbone suppresses high glucose and LPS-induced inflammation in THP-1-derived macrophages by inhibiting the NF-κB/TLR signaling pathway.

Diabetes mellitus is characterized by hyperglycemia. Low-grade bacterial infection with hyperglycemia in patients with diabetes is associated with atherosclerosis development. Therefore, this study hypothesized that macrophages lead to more severe diabetic complications under combined conditions of high glucose and lipopolysaccharide (LPS)-induced inflammation than under normoglycemic conditions. Zerumbone is the main component of Zingiber zerumbet Smith essential oil, a type of wild ginger. It possesses various biomedical activities, including antibacterial, antioxidant, anti-inflammatory, and anticancer activities; however, the precise mechanism of its anti-inflammatory and epigenetic effects is not fully understood. In this study, the effects of zerumbone on the secretion of proinflammatory cytokines and its underlying regulatory mechanism were investigated in THP-1-derived macrophages exposed to high glucose and LPS. THP-1-derived macrophages were cultured under normoglycemic (5.5 mmol/L glucose) or hyperglycemic (25 mmol/L glucose) conditions in the absence or presence of zerumbone (5-50 µM) for 48 hours and then treated with 100 ng/mL LPS for 6 hours. Zerumbone (25 and 50 µM) suppressed the production of tumor necrosis factor-α and interleukin-6 and the activation of cyclooxygenase-2, nuclear factor-κB, histone deacetylases 3 proteins, and Toll-like receptor messenger RNA (mRNA) and increased the transcription of the sirtuin 1 (SIRT1), SIRT3, and SIRT6 mRNAs. Taken together, our results suggest that zerumbone may exert beneficial effects on diabetes and its complications.

Phenethyl Isothiocyanate Improves Lipid Metabolism and Inflammation via mTOR/PPARγ/AMPK Signaling in the Adipose Tissue of Obese Mice.

Obesity is defined as excess adipose mass that causes serious health problems. Phenethyl isothiocyanate (PEITC) is a major and relatively nontoxic compound of the isothiocyanates. Although many studies have demonstrated that PEITC is a potent substance with physiological activities, such as anticancer activity, the precise mechanism for the effects of PEITC on inflammation and lipid metabolism in adipose tissue is not clear. Our study aimed to clarify the effects of PEITC supplements on the adipose tissue in obesity induced with a high-fat/cholesterol diet, and the underlying mechanisms. We induced obesity by feeding the mice with high fat with 1% cholesterol diet (HFCD) for 13 weeks. Mice were divided into five groups: normal diet (CON), HFCD, HFCD with 3 mg/(kg·d) gallic acid (HFCD+G), and HFCD with 30 and 75 mg/(kg·d) PEITC (HFCD+P30 and HFCD+P75, respectively). Using western blotting and quantitative polymerase chain reaction (qPCR) analysis of the adipose tissue, we determined the expression of lipid metabolism-related genes and inflammation-related genes. In the HFCD, the expression level of nuclear factor-κB (NF-κB), lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1), and cyclooxygenase-2 (COX-2), was higher compared with that in the CON. Moreover, in the HFCD, the expression of p-mechanical targets of the rapamycin (mTOR) was increased, whereas that of p-AMP-activated protein kinase (AMPK) was decreased compared with that in the CON. Nevertheless, these decreased expression levels of p-AMPK and increased levels of LOX-1, p-mTOR, peroxisome proliferator-activated receptor gamma (PPARγ), NF-κB, and COX-2, were alleviated by PEITC supplementation. Therefore, we suggest that PEITC might be a potential preventive agent for ameliorating obesity-induced inflammation and adipogenesis by modulating the mTOR/AMPK/PPARγ pathway.

Dietary Patterns and Mild Cognitive Impairment Risk in Korean Adults over 50 Years Old.

The prevalence of age-related diseases such as dementia and cognitive disorders is rapidly increasing. This study aimed to identify the dietary patterns associated with mild cognitive impairment (MCI) in adults aged over 50 years. This cross-sectional study investigated dietary patterns associated with cognitive function among older adults hospitalized in Gwangju province. Global cognitive function was assessed using the Mini-Mental State Examination. Diet information was obtained using a food frequency questionnaire with 112 food items and 24-h dietary recall. Using a principal component analysis, we identified three dietary patterns, "legumes and vegetables", "beverage and nuts", and "white rice". The "beverage and nuts" pattern was inversely associated with the prevalence of high MCI after adjusting for covariates (third vs. first tertile, adjusted odds ratio: 0.333; 95% confidence interval: 0.133∼0.831; P<0.05). The white rice pattern was associated with the prevalence of MCI in the crude analysis. However, after adjusting for all confounding factors, no association was found. The "beverage and nuts" pattern was inversely associated with the prevalence of MCI. In the future, longitudinal population-based studies and randomized clinical trials are required to confirm the effect of potential dietary patterns on cognitive impairment and reveal the underlying mechanism of their association.

Neck Circumference as a Predictor of Metabolic Syndrome in Koreans: A Cross-Sectional Study.

Metabolic syndrome (MetS) is a complex metabolic disorder and a high-risk condition for type 2 diabetes and cardiovascular disease. Rapid screening of at-risk individuals using accurate and time-saving tools is effective in disease management. Using the Korea National Health and Nutrition Examination Survey (KNHANES) data, we collected data from 2234 participants suitable for the study design, of which 974 (43.6%) were men and 1260 (56.4%) were women. We used receiver operating characteristic (ROC) curve analysis to estimate the optimal sex-specific neck circumference (NC) cut-off point to predict the MetS risk. To analyze the risk of MetS according to the estimated NC, logistic regression analysis was performed to identify the confounding factors. The result of the ROC analysis showed that the optimal neck cut-off points for predicting the risk of MetS were 38.25 cm (AUC: 0.759, 95% CI: 0.729-0.790) in men and 33.65 cm (AUC: 0.811, 95% CI: 0.782-0.840) in women. In the upper NC cut-off point compared to the lower NC cut-off point, NC was associated with an increased MetS risk by 2.014-fold (p = 0.010) in men and 3.650-fold (p < 0.001) in women, after adjustments. The current study supports NC as an effective anthropometric indicator for predicting the risk of MetS. It is suggested that more studies should be conducted to analyze the disease prediction effect of the combined application of anthropometric indicators currently in use and NC.

Protective effects of phenethyl isothiocyanate on foam cell formation by combined treatment of oxidized low-density lipoprotein and lipopolysaccharide in THP-1 macrophage.

Accumulation of cholesterol-laden macrophage foam cells characteristic of early stage atherosclerotic lesions. Phenethyl isothiocyanate (PEITC) is a naturally occurring isothiocyanate found in cruciferous vegetables that has reported a variety of activities including antioxidant and anti-inflammatory properties. However, the protective effect of PEITC on foam cell formation and its precise mechanism is not yet clear. Therefore, we investigated whether PEITC suppresses foam cell formation and regulates the expression of genes related to lipid accumulation, cholesterol efflux, and inflammation in THP-1 derived-macrophages. We exposed THP-1 derived-macrophages to oxidized low-density lipoprotein (ox-LDL) (20 µg/mL) and lipopolysaccharide (LPS) (500 ng/ml) to mimic foam cell formation. Here, PEITC downregulated the expression of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), cluster of differentiation 36 (CD36), scavenger receptor A1 (SR-A1), and nuclear factor-κB (NF-κB), while upregulated ATP binding cassette subfamily A member 1 (ABCA1)/liver-X-receptor α (LXR-α)/peroxisome proliferator-activated receptor gamma (PPARγ) and sirtuin 1 (SIRT1) expression compared to co-treated with ox-LDL and LPS. Taken together, PEITC, at least in part, inhibits foam cell formation and reduces lipid accumulation in foam cells. Therefore, we suggest that PEITC may be a potential candidate for the treatment and prevention of vascular inflammation and atherosclerosis.

Dietary glucosinolates inhibit splenic inflammation in high fat/cholesterol diet-fed C57BL/6 mice.

BACKGROUND/OBJECTIVES: Obesity is associated with chronic inflammation. The spleen is the largest organ of the lymphatic system and has an important role in immunity. Obesity-induced inflammatory responses are triggered by Toll-like receptor (TLR)-myeloid differentiation primary response 88 (MyD88) pathway signaling. Phenethyl isothiocyanate (PEITC) and 3,3'-diindolylmethane (DIM), major dietary glucosinolates present in cruciferous vegetables, have been reported to produce anti-inflammatory effects on various diseases. However, the effects of PEITC and DIM on the obesity-induced inflammatory response in the spleen are unclear. The purpose of this study was to examine the anti-inflammatory effects of PEITC and DIM on the spleen and their mechanism in high fat/cholesterol diet (HFCD)-fed C57BL/6 mice. MATERIALS/METHODS: We established an animal model of HFCD-induced obesity using C57BL/6 mice. The mice were divided into six groups: normal diet with AIN-93G diet (CON), high fat diet (60% calories from fat) with 1% cholesterol (HFCD), HFCD with PEITC 30 mg/kg/day or 75 mg/kg/day (HFCD+P30, HFCD+P75), and HFCD with DIM 1.5 mg/kg/day or 7.5 mg/kg/day (HFCD+D1.5, HFCD+D7.5). Enzyme-linked immunosorbent assay was used to evaluate pro-inflammatory cytokine secretion. Western blot and quantitative polymerase chain reaction were used to analyze protein and mRNA levels of nuclear factor kappa B (NF-κB) p65, interleukin 6 (IL-6), cyclooxygenase 2 (COX-2), TLR2, TLR4, and MyD88 in spleen tissue. RESULTS: Serum IL-6 levels were significantly higher in the HFCD group than in groups fed a HFCD with PEITC or DIM. Levels of NF-κB p65 protein and TLR2/4, MyD88, NF-κB p65, IL-6, and COX-2 mRNA were significantly higher in the HFCD group than in the CON group and were reduced by the PEITC and DIM supplements. CONCLUSIONS: PEITC- and DIM-supplemented diets improved splenic inflammation by modulating the TLR2/4-MyD88 pathway in HFCD-fed mice. We suggest that dietary glucosinolates may at least partially improve obesity-induced inflammation of the spleen.

Hesperetin suppresses LPS/high glucose-induced inflammatory responses via TLR/MyD88/NF-κB signaling pathways in THP-1 cells.

BACKGROUND/OBJECTIVES: Unregulated inflammatory responses caused by hyperglycemia may induce diabetes complications. Hesperetin, a bioflavonoid, is a glycoside in citrus fruits and is known to have antioxidant and anticarcinogenic properties. However, the effect of inflammation on the diabetic environment has not been reported to date. In this study, we investigated the effect of hesperetin on proinflammatory cytokine secretion and its underlying mechanistic regulation in THP-1 macrophages with co-treatment LPS and hyperglycemic conditions. MATERIALS/METHODS: THP-1 cells differentiated by PMA (1 µM) were cultured for 48 h in the presence or absence of hesperetin under normoglycemic (5.5 mM/L glucose) or hyperglycemic (25 mM/L glucose) conditions and then treated with LPS (100 ng/mL) for 6 h before harvesting. Inflammation-related proteins and mRNA levels were evaluated by enzyme-linked immunosorbent assay, western blot, and quantitative polymerase chain reaction analyses. RESULTS: Hesperetin (0-100 µM, 48 h) treatment did not affect cell viability. The tumor necrosis factor-α and interleukin-6 levels increased in cells co-treated with LPS under hyperglycemic conditions compared to normoglycemic conditions, and these increases were decreased by hesperetin treatment. The TLR2/4 and MyD88 activity levels increased in cells co-treated with LPS under hyperglycemic conditions compared to normoglycemic conditions; however, hesperetin treatment inhibited the TLR2/4 and MyD88 activity increases. In addition, nuclear factor-κB (NF-κB) and Acetyl-NF-κB levels increased in response to treatment with LPS under hyperglycemic conditions compared to normoglycemic conditions, but those levels were decreased when treated with hesperetin. SIRT3 and SIRT6 expressions were increased by hesperetin treatment. CONCLUSIONS: Our results suggest that hesperetin may be a potential agent for suppressing inflammation in diabetes.

Effects of epigallocatechin gallate on regulatory T cell number and function in obese v. lean volunteers.

Obesity predisposes to an increased incidence of diabetes and CVD. Also, obesity is a pro-inflammatory state. Regulatory T cells (Tregs) are essential negative regulators of inflammation and are down-regulated in pro-inflammatory states. Animal models of obesity are associated with decreased Tregs. The dietary modulation of Tregs could be used as a therapeutic strategy to control inflammation. Epigallocatechin gallate (EGCG) is a potent anti-inflammatory agent and an active ingredient of green tea and is suggested to have a role as a preventive agent in obesity, diabetes and CVD. The role of EGCG in the modulation of Tregs has, however, not been studied. Thus, the aim of the present study was to determine the effect of EGCG on the number and function of Tregs in obese and lean human subjects in vitro, and to delineate its specific regulation mechanisms. Tregs were isolated from normal-weight and obese subjects. Tregs were cultured in the absence or presence of EGCG (20 mum) for 24 h. Foxp3-expressing Tregs were enumerated using flow cytometry. Histone deacetylase (HDAC) activity and nuclear NF-kappaBp65 level were measured by ELISA and Western blots. Obese subjects had lower Tregs and IL-10 production than lean subjects. EGCG treatment significantly enhanced the number of Foxp3-expressing Tregs and IL-10 production in vitro (P < 0.05) in both groups. Also, EGCG decreased NF-kappaB activity and increased HDAC activity and HDAC-2 expression in Tregs (P < 0.05) in both groups. Thus, in part, EGCG enhances the functionality of Tregs, i.e. IL-10 production and number by suppressing the NF-kappaB signalling pathway via inducing epigenetic changes.

C-reactive protein induces M-CSF release and macrophage proliferation.

Inflammation is pivotal in atherosclerosis. M-CSF regulates macrophage growth and differentiation and plays a role in atherogenesis. C-reactive protein (CRP), a cardiovascular risk marker, may promote atherogenesis. However, the effects of CRP on M-CSF release and subsequent macrophage proliferation have not been examined previously. Human aortic endothelial cells (HAEC) were incubated with boiled CRP or native CRP 12.5, 25, and 50 microg/mL for 12-15 h, and M-CSF release was examined by flow cytometry and ELISA. CRP resulted in a significant and dose-dependent increase in M-CSF mRNA and secretion from HAEC as well as human monocyte-derived macrophages (HMDM; P<0.01). Furthermore, conditioned medium (5%) from HAEC pretreated with CRP, when incubated with HMDM, increased macrophage proliferation significantly. This was blocked with M-CSF antibody but not irrelevant antibody. Inhibition of NF-kappaB resulted in significant abrogation of CRP-induced M-CSF release and subsequent macrophage proliferation. Antibodies to CD32 and CD64 but not CD16 abrogated CRP-induced M-CSF release. Thus, CRP up-regulates M-CSF release from HMDM and HAEC and increased macrophage proliferation. These effects appear to be mediated via activation of NF-kappaB via CD32 and CD64. These studies provide further evidence for a proatherogenic role for CRP.

MeCP2 regulates gene expression through recognition of H3K27me3.

MeCP2 plays a multifaceted role in gene expression regulation and chromatin organization. Interaction between MeCP2 and methylated DNA in the regulation of gene expression is well established. However, the widespread distribution of MeCP2 suggests it has additional interactions with chromatin. Here we demonstrate, by both biochemical and genomic analyses, that MeCP2 directly interacts with nucleosomes and its genomic distribution correlates with that of H3K27me3. In particular, the methyl-CpG-binding domain of MeCP2 shows preferential interactions with H3K27me3. We further observe that the impact of MeCP2 on transcriptional changes correlates with histone post-translational modification patterns. Our findings indicate that MeCP2 interacts with genomic loci via binding to DNA as well as histones, and that interaction between MeCP2 and histone proteins plays a key role in gene expression regulation.

Phenethyl Isothiocyanate Protects against High Fat/Cholesterol Diet-Induced Obesity and Atherosclerosis in C57BL/6 Mice.

This study concerns obesity-related atherosclerosis, hyperlipidemia, and chronic inflammation. We studied the anti-obesity and anti-atherosclerosis effects of phenethyl isothiocyanate (PEITC) and explored their underlying mechanisms. We established an animal model of high fat/cholesterol-induced obesity in C57BL/6 mice fed for 13 weeks. We divided the mice into five groups: control (CON), high fat/cholesterol (HFCD), HFCD with 3 mg/kg/day gallic acid (HFCD + G), and HFCD with PEITC (30 and 75 mg/kg/day; HFCD + P30 and P75). The body weight, total cholesterol, and triglyceride were significantly lower in the HFCD + P75 group than in the HFCD group. Hepatic lipid accumulation and atherosclerotic plaque formation in the aorta were significantly lower in both HFCD + PEITC groups than in the HFCD group, as revealed by hematoxylin and eosin (H&E) staining. To elucidate the mechanism, we identified the expression of genes related to inflammation, reverse cholesterol transport, and lipid accumulation pathway in the liver. The expression levels of peroxisome proliferator activated receptor gamma (PPARγ), liver-X-receptor α (LXR-α), and ATP binding cassette subfamily A member 1 (ABCA1) were increased, while those of scavenger receptor A (SR-A1), cluster of differentiation 36 (CD36), and nuclear factor-kappa B (NF-κB) were decreased in the HFCD + P75 group compared with those in the HFCD group. Moreover, PEITC modulated H3K9 and H3K27 acetylation, H3K4 dimethylation, and H3K27 di-/trimethylation in the HFCD + P75 group. We, therefore, suggest that supplementation with PEITC may be a potential candidate for the treatment and prevention of atherosclerosis and obesity.

Delphinidin, an anthocyanidin in pigmented fruits and vegetables, induces apoptosis and cell cycle arrest in human colon cancer HCT116 cells.

Because of unsatisfactory treatment options for colon cancer, there is a need to develop novel preventive approaches for this malignancy. One such strategy is through chemoprevention by the use of non-toxic dietary substances and botanical products. Delphinidin, an anthocyanidin in pigmented fruits and vegetables, possesses strong anti-oxidant and anti-inflammatory properties. In the present study, we investigated the antiproliferative and proapoptotic properties of delphinidin in human colon cancer HCT116 cells. We found that treatment of cells with delphinidin (30-240 microM; 48 h) resulted in (i) decrease in cell viability (ii) induction of apoptosis, (iii) cleavage of PARP, (iv) activation of caspases-3, -8, and -9, (v) increase in Bax with a concomitant decrease in Bcl-2 protein, and (vi) G2/M phase cell cycle arrest. NF-kappaB provides a mechanistic link between inflammation and cancer, and is a major factor controlling the ability of both pre-neoplastic and malignant cells to resist apoptosis-based tumor surveillance mechanisms. We therefore, determined the effect of delphinidin on NF-kappaB signaling pathway. The immunoblot, ELISA and EMSA analysis demonstrated that the treatment of HCT116 cells with delphinidin resulted in the inhibition of (i) IKKalpha, (ii) phosphorylation and degradation of IkappaBalpha, (iii) phosphorylation of NF-kappaB/p65 at Ser(536), (iv) nuclear translocation of NF-kappaB/p65, (v) NF-kappaB/p65 DNA binding activity, and (vi) transcriptional activation of NF-kappaB. Our results suggest that delphinidin treatment of HCT116 cells suppressed NF-kappaB pathway, resulting in G2/M phase arrest and apoptosis. We suggest that delphinidin could have potential in inhibiting colon cancer growth.