Caprylic acid and medium-chain triglycerides inhibit IL-8 gene transcription in Caco-2 cells: comparison with the potent histone deacetylase inhibitor trichostatin A

The Protective Effect of Octanoic Acid on Sepsis: A Review

Sepsis, a systemic inflammation that occurs in response to a bacterial infection, is a significant medical challenge. Research conducted over the past decade has indicated strong associations among a patient's nutritional status, the composition of their gut microbiome, and the risk, severity, and prognosis of sepsis. Octanoic acid (OA) plays a vital role in combating sepsis and has a protective effect on both animal models and human patients. In this discussion, the potential protective mechanisms of OA in sepsis, focusing on its regulation of the inflammatory response, immune system, oxidative stress, gastrointestinal microbiome and barrier function, metabolic disorders and malnutrition, as well as organ dysfunction are explored. A comprehensive understanding of the mechanisms by which OA act may pave the way for new preventive and therapeutic approaches to sepsis.

Lower caprylate and acetate levels in the breast milk is associated with atopic dermatitis in infancy

BACKGROUND

Atopic dermatitis (AD) occurs in exclusively breastfed infants. As fatty acids have some immunomodulatory effect, we aimed to investigate the influence of fatty acid compositions in breast milk (BM) on the development of AD in exclusively breastfed infants.

METHODS

We enrolled two- to four-month-old exclusively breastfed infants. The objective SCORing Atopic Dermatitis (objSCORAD) was evaluated. The lipid layer of BM was analyzed by gas chromatography for fatty acid levels. Medical charts were reviewed.

RESULTS

Forty-seven AD infants and 47 healthy controls were enrolled. The objSCORAD was 20.5 ± 1.7 (shown as mean ± SEM) in the AD group. The age, sex, parental atopy history, and nutrient intake of mothers were not significantly different between two groups. The palmitate and monounsaturated fatty acid (MUFA) levels in BM positively correlated with objSCORAD, while caprylate, acetate, and short-chain fatty acid (SCFA) levels negatively correlated with objSCORAD (p = .031, .019, .039, .013, .022, respectively). However, the butyrate levels in BM were not significantly different. The caprylate and acetate levels in BM were significantly associated with the presence of infantile AD (p = .021 and .015, respectively) after adjusting for age, sex, parental allergy history, MUFA, palmitate, and SCFA levels in BM. ObjSCORAD in infancy was significantly associated with persistent AD (p = .026) after adjusting for age, sex, parental atopy history, caprylate, palmitate, MUFA, acetate, and SCFA levels in BM.

CONCLUSION

Caprylate and acetate levels in BM for exclusively breastfed infants were negatively associated with objSCORAD. Lower caprylate and acetate in BM might be the risk factors for infantile AD, while butyrate in BM was not associated with infantile AD.

Anti-Colon Cancer Activity of Novel Peptides Isolated from In Vitro Digestion of Quinoa Protein in Caco-2 Cells

Quinoa peptides are the bioactive components obtained from quinoa protein digestion, which have been proved to possess various biological activities. However, there are few studies on the anticancer activity of quinoa peptides, and the mechanism has not been clarified. In this study, the novel quinoa peptides were obtained from quinoa protein hydrolysate and identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The anticancer activity of these peptides was predicted by PeptideRanker and evaluated using an antiproliferative assay in colon cancer Caco-2 cells. Combined with the result of histone deacetylase 1 (HDAC1) inhibitory activity assay, the highly anticancer activity peptides FHPFPR, NWFPLPR, and HYNPYFPG were screened and further investigated. Molecular docking was used to analyze the binding site between peptides and HDAC1, and results showed that three peptides were bound in the active pocket of HDAC1. Moreover, real-time quantitative polymerase chain reaction (RT-qPCR), and Western blot showed that the expression of HDAC1, NFκB, IL-6, IL-8, Bcl-2 was significantly decreased, whereas caspase3 expression showed a remarkable evaluation. In conclusion, quinoa peptides may have the potential to protect against cancer development by inhibiting HDAC1 activity and regulating the expression of the cancer-related genes, which indicates that these peptides could be explored as functional foods to alleviate colon cancer.

Therapeutic deep eutectic solvent-based microemulsion enhances anti-inflammatory efficacy of curcuminoids and aromatic-turmerone extracted from Curcuma longa L

To diminish chemical waste and improve the delivery of Curcuma longa L. (CL) constituents, microemulsions based on hydrophobic deep eutectic solvents (HDESs) were designed as ready-to-use solvents for CL extraction. The microemulsion (ME) of the ME-23 formulation (HDES/Tween 80 : propylene glycol (1 : 1)/water, 25/70/5) displayed CL extraction yields of 1.69, 3.04, 7.36, and 1.39 wt% of bisdemethoxycurcumin, demethoxycurcumin, curcumin, and aromatic-turmerone, respectively. The ME-23 without CL chemical constituents and ME-23-based CL extract inhibited NO production with an IC₅₀ value of 0.0136 ± 0.0023%v/v and a curcumin IC₅₀ value of 75.2 ± 6.7 nM, respectively, and simultaneously lowered inflammatory cytokines tumor necrosis factor-α, interleukin (IL)-6, and IL-1β production in lipopolysaccharide-activated murine macrophages. Authentic curcumin in ME-23 possessed superior NO inhibitory activity, which was 103-fold more effective than curcumin prepared in the conventional solvent dimethyl sulfoxide. ME-23 was also capable of delivering curcumin into murine macrophages. After 30 days of storage in HDES and HDES-based ME, curcumin remained more than 90%. ME-23 provides advantages for CL extraction, constituent delivery, and anti-inflammatory functions that can be applied to pharmaceutical and cosmetic products.

A novel HDES-based microemulsion system with anti-inflammatory activity serves as an extraction solvent of Curcuma longa L.

Serenoa repens and its effects on male sexual function. A systematic review and meta-analysis of clinical trials

BACKGROUND

Serenoa repens (SR) is a plant used to treat benign prostatic hyperplasia and prostatitis. We know that SR act as a 5α-reductase inhibitor, moreover, several studies have proved that SR has anti-inflammatory and antioxidant properties. There is some belief among patients that SR may negatively impact male sexual function. Such belief is circulating in non-medical social networks and is perhaps maintained by patients as a result of incorrect web surfing. However, it is also possible that SR may exert a "nocebo" effect thus negatively impacting on the general well-being of patients.

OBJECTIVE

The aim of this study is to investigate whether SR is causing negative effects on male sexual function.

METHODS

To ascertain the effect of SR on male sexual function, we conducted a systematic review and meta-analysis, by performing an electronic database search in accordance with the PRISMA guidelines.

RESULTS

Out of 20 included papers, 8 papers reported comparisons of SR with placebo, and 7 studies reported comparisons of SR with tamsulosin. The standardized mean difference of changes from baseline scores of sexual function was not significantly different between SR and placebo (SMD: 0.43, 95% CI: 0.18 to 1.05; I^2 = 95%). Similarly, no significant mean differences in the Male Sexual Function-4 (MSF-4) test scores were found between SR and tamsulosin (SMD: -0.31, 95% CI: -0.82 to 0.19; I^2 = 90%).

CONCLUSIONS

We found no statistically significant differences between negative effects on sexual function in patients treated with SR compared to patients who received placebo. The results of our meta-analysis are similar to those of other systematic reviews. Studies are warranted to ascertain whether any such effects might occur as a result of a nocebo effect.

Sodium caprylate improves intestinal mucosal barrier function and antioxidant capacity by altering gut microbial metabolism

Short-chain fatty acids (SCFA) produced by gut microbial metabolism have been reported to regulate the immunological response and intestinal health of the host by activating G protein-coupled receptors (GPR). It is unclear whether medium-chain fatty acids (MCFA) improve the intestinal barrier function by activating GPR. This study was conducted to investigate the effects of sodium caprylate and sodium butyrate on antioxidant capacity and intestinal barrier function in IPEC-J2 treated with H₂O₂ and C57/BL6 mouse models. For in vitro and in vivo assays, mice and oxidation-damaged IPEC-J2 (NC) were treated with sodium caprylate (SC) and sodium butyrate (PC) to determine intestinal barrier and antioxidant functions of the host. In vitro, SC treatment increased the concentrations of glutathione and total antioxidant capacity, and expression of claudin-1 and claudin-3 in oxidation-damaged IPEC-J2 (P < 0.05). In vivo, SC treatment improved growth performance, intestinal morphology, expression of claudin-3, and activity of superoxide dismutase in mice (P < 0.05), but decreased interleukin-1β and interferon-γ concentrations in serum compared to the NC group (P < 0.05). Treatment with SC increased the populations of Prevotella_9 in the ileum and Lachnoclostridium and Roseburia in the colon, but decreased the abundances of Streptococcus and Enterococcus in the ileum and Lactobacillus and Clostridium_sensu_stricto_1 in the colon compared with the NC group (P < 0.05). Concentrations of SCFA increased in the SC and PC groups than in the NC group (P < 0.05). Ileal protein expression of GPR 43 in the SC and PC groups was significantly greater than that in the NC group (P < 0.05). In conclusion, our findings confirmed the important role of sodium caprylate in improving intestinal barrier function and gut health by activating GPR 43 through regulating gut microbial metabolism.

The effect of a 6-month ketogenic medium-chain triglyceride supplement on plasma cardiometabolic and inflammatory markers in mild cognitive impairment

INTRODUCTION

Mild cognitive impairment (MCI) is often accompanied by metabolic abnormalities and inflammation that might play a role in the development of cognitive impairment. The use of ketogenic medium-chain triglycerides (kMCT) to improve cognition in this population has shown promising results but remains controversial because of the potentially detrimental effect of elevated intake of saturated fatty acids on cardiovascular (CV) health and perhaps inflammatory processes. The primary aim of this secondary data analysis report is to describe changes in cardiometabolic markers and peripheral inflammation during a 6-month kMCT intervention in MCI.

METHODS

Thirty-nine participants with MCI completed the intervention of 30 g/day of either a kMCT drink or calorie-matched placebo (high-oleic acid) for 6 months. Plasma concentrations of cardiometabolic and inflammatory markers were collected before (fasting state) and after the intervention (2 h following the last drink).

RESULTS

A mixed model ANOVA analysis revealed a time by group interaction for ketones (P < 0.001), plasma 8:0 and 10:0 acids (both P < 0.001) and IL-8 (P = 0.002) with follow up comparison revealing a significant increase in the kMCT group (+48%, P = 0.005), (+3,800 and +4,900%, both P < 0.001) and (+147%, P < 0.001) respectively. A main effect of time was observed for insulin (P = 0.004), triglycerides (P = 0.011) and non-esterified fatty acids (P = 0.036).

CONCLUSION

Under these study conditions, 30 g/d of kMCT taken for six months and up to 2-hour before post-intervention testing had minimal effect on an extensive profile of circulating cardiometabolic and inflammatory markers as compared to a placebo calorie-matched drink. Our results support the safety kMCT supplementation in individuals with MCI. The clinical significance of the observed increase in circulating IL-8 levels is presently unknown and awaits future studies.

Nutrition, IBD and Gut Microbiota: A Review

Inflammatory bowel disease (IBD) is a chronic relapsing–remitting systemic disease of the gastrointestinal tract, characterized by an inflammatory process that requires lifelong treatment. The underlying causes of IBD are still unclear, as this heterogeneous disorder results from a complex interplay between genetic variability, the host immune system and environmental factors. The current knowledge recognizes diet as a risk factor for the development of IBD and attributes a substantial pathogenic role to the intestinal dysbiosis inducing an aberrant mucosal immune response in genetically predisposed individuals. This review focused on the clinical evidence available that considers the impact of some nutrients on IBD onset and the role of different diets in the management of IBD and their effects on the gut microbiota composition. The effects of the Specific Carbohydrate Diet, low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diet, gluten free diet, anti-inflammatory diet and Mediterranean diet are investigated with regard to their impact on microbiota and on the evolution of the disease. At present, no clear indications toward a specific diet are available but the assessment of dysbiosis prior to the recommendation of a specific diet should become a standard clinical approach in order to achieve a personalized therapy.

Caprylic acid suppresses inflammation via TLR4/NF-κB signaling and improves atherosclerosis in ApoE-deficient mice

Background

As reported previously by our group, medium-chain triglycerides can ameliorate atherosclerosis. Given that TLR4 is closely related to atherosclerosis, we hypothesized herein that caprylic acid (C8:0) would suppress inflammation via TLR4/NF-κB signaling and further promote the amelioration of atherosclerosis in apoE- deficient (apoE^-/-) mice.

Methods

Fifty 6-week male apoE^-/- mice were randomly allocated into five diet groups: a high-fat diet (HFD) without or with 2% caprylic acid (C8:0), capric acid (C10:0), stearic acid (C18:0), or linolenic acid (C18:3). RAW246.7 cells were treated with caprylic acid (C8:0), docosahexenoic acid (DHA), palmitic acid (C16:0), and lipopolysaccharide (LPS) with or without TLR4 knock-down (TLR4-KD). The serum lipid profiles, inflammatory biomolecules, and mRNA and protein expression levels were measured. Atherosclerotic lesions that occurred in the aorta and aortic sinuses were evaluated and quantified.

Results

Our results indicated that C8:0 reduced body fat, improved the lipid profiles, suppressed inflammatory cytokine production, downregulated aortic TLR4, MyD88, NF-κB, TNF-α, IKKα, and IKKβ mRNA expression, and alleviated atherosclerosis in the apoE^-/- mice (P < 0.05). In RAW 264.7 cells, C8:0 diminished the inflammatory response and both mRNA and protein expression of TLR4, MyD88, NF-κB, and TNF-α compared to those in the LPS and C16:0 groups (P < 0.05). However, in the TLR4-KD RAW 264.7 cells, C8:0 significantly upregulated NF-κB mRNA and protein expression compared to those in the C16:0 and DHA groups.

Conclusions

These results suggest that C8:0 functions via TLR4/NF-κB signaling to improve the outcomes of apoE^-/- mice through suppressing inflammation and ameliorating atherosclerosis. Thus, C8:0 may represent as a promising nutrient against chronic inflammatory diseases.

Egg Protein Transferrin-Derived Peptides IRW and IQW Regulate Citrobacter rodentium-Induced, Inflammation-Related Microbial and Metabolomic Profiles

Bioactive peptides that target the gastrointestinal tract can strongly affect the health of animals and humans. This study aimed to evaluate the abilities of two peptides derived from egg albumin transferrin, IRW and IQW, to treat enteritis in a mouse model of Citrobacter rodentium-induced colitis by evaluating serum metabolomics and gut microbes. Forty-eight mice were randomly assigned to six groups: basal diet (CTRL), intragastric administration Citrobacter rodentium (CR), basal diet with 0.03%IRW (IRW), CR with 0.03% IRW (IRW+CR), basal diet with 0.03%IQW (IQW) and CR with 0.03% IQW (IQW+CR). CR administration began on day 10 and continued for 7 days. After 14 days of IRW and IQW treatment, serum was collected and subjected to a metabolomics analysis. The length and weight of each colon were measured, and the colon contents were collected for 16srRNA sequencing. The colons were significantly longer in the CR group, compared to the CTRL group. A serum metabolomics analysis revealed no significant difference in microbial diversity between the six groups. Compared with the CTRL group, the proportions of Firmicutes and Actinobacteria species decreased significantly and the proportions of Bacteroidetes and Proteobacteria species increased in the CR group. There were no significant differences between the CTRL and other groups. The serum metabolomics analysis revealed that Infected by CR increased the levels of oxalic acid, homogentisic acid and prostaglandin but decreased the levels of L-glutamine, L-acetyl carnitine, 1-methylhistidine and gentisic acid. Therefore, treatment with IRW and IQW was shown to regulate the intestinal microorganisms associated with colonic inflammation and serum metabolite levels, thus improving intestinal health.

Roles of TRPA1 and TRPV1 in cigarette smoke -induced airway epithelial cell injury model

Transient receptor potential protein (TRP) ion channels TRPA1 and TRPV1 may be important in mediating airway tissue injury and inflammation. This study was designed to clarify the role of TRPA1 and TRPV1 channels in cigarette smoke extract (CSE)-induced damage to bronchial and alveolar epithelial cells. Alveolar epithelial (A549) cells and bronchial epithelial (Beas-2B) cells were treated with CSE in the presence and absence of a TRPA1 inhibitor (100 μM, A967079), a TRPV1 inhibitor (100 μM, AMG9810) or both. DCFH-DA and MitoSOX Red probes were used to assay intracellular and mitochondrial oxidative stress, respectively. The mRNA levels of inflammatory mediators (IL-1β, IL-8, IL-18, IL-33) and antioxidants (HO-1, NQO1, MnSOD, catalase) and the protein expression levels of mitochondrial and inflammasome factors (MFN2, OPA1, DRP1, MFF, NLRP3,caspase-1) were respectively detected by RT-PCR and Western Blot. The results were validated in TRPA1 shRNA and TRPV1 shRNA cells. In both cell types, 10% CSE increased intracellular and mitochondrial oxidative stress, induced Ca²⁺ influx, increased inflammatory gene expression, reduced antioxidant gene expression and inhibited the activities of mitochondrial respiratory chain (MRC) complexes. 10% CSE increased the expression of mitochondrial fission proteins (MFF and DRP1), Caspase-1 and NLRP3 protein expression and decreased that of mitochondrial fusion proteins (MFN2 and OPA1). Both inhibitors and gene-knockout of TRPA1 and TRPV1 reduced oxidative stress, blocked Ca²⁺ influx, and inhibited inflammatory and increased antioxidant gene expression. They also prevented the changes in mitochondrial fission and fusion proteins and in MRC complexes activities induced by CSE. Both TRPA1 and TRPV1 mediate CSE-induced damage of bronchial and alveolar epithelial cells via modulation of oxidative stress, inflammation and mitochondrial damage and their inhibition should be considered as potential therapy for COPD.

Hookworm-Derived Metabolites Suppress Pathology in a Mouse Model of Colitis and Inhibit Secretion of Key Inflammatory Cytokines in Primary Human Leukocytes

Iatrogenic hookworm therapy shows promise for treating disorders that result from a dysregulated immune system, including inflammatory bowel disease (IBD). Using a murine model of trinitrobenzenesulfonic acid-induced colitis and human peripheral blood mononuclear cells, we demonstrated that low-molecular-weight metabolites derived from both somatic extracts (LMWM-SE) and excretory-secretory products (LMWM-ESP) of the hookworm, Ancylostoma caninum, display anti-inflammatory properties. Administration to mice of LMWM-ESP as well as sequentially extracted fractions of LMWM-SE using both methanol (SE-MeOH) and hexane-dichloromethane-acetonitrile (SE-HDA) resulted in significant protection against T cell-mediated immunopathology, clinical signs of colitis, and impaired histological colon architecture. To assess bioactivity in human cells, we stimulated primary human leukocytes with lipopolysaccharide in the presence of hookworm extracts and showed that SE-HDA suppressed ex vivo production of inflammatory cytokines. Gas chromatography-mass spectrometry (MS) and liquid chromatography-MS analyses revealed the presence of 46 polar metabolites, 22 fatty acids, and five short-chain fatty acids (SCFAs) in the LMWM-SE fraction and 29 polar metabolites, 13 fatty acids, and six SCFAs in the LMWM-ESP fraction. Several of these small metabolites, notably the SCFAs, have been previously reported to have anti-inflammatory properties in various disease settings, including IBD. This is the first report showing that hookworms secrete small molecules with both ex vivo and in vivo anti-inflammatory bioactivity, and this warrants further exploration as a novel approach to the development of anti-inflammatory drugs inspired by coevolution of gut-dwelling hookworms with their vertebrate hosts.

Inflammatory mechanisms and oxidative stress in prostatitis: the possible role of antioxidant therapy

This article focuses on the role that oxidative stress plays in chronic prostatitis, not only with respect to the known impact on symptoms and fertility but also especially in relation to possible prostate cancer development. Prostatitis is the most common urologic disease in adult males younger than 50 years and the third most common urologic diagnosis in males older than 50 years. If the germ-causing acute prostatitis is not eliminated, the inflammatory process becomes chronic. Persistent inflammation causes ongoing production of large quantities of pro-inflammatory cytokines and both oxygen and nitrogen reactive species, with consequent activation of transcription factor nuclear factor-kappa B (NF-κB) and genes encoding for further production of pro-inflammatory cytokines, chemotactic factors, and growth factors. Confirming the role of oxidative stress in chronic prostatitis, several studies have demonstrated the presence of oxidative stress markers in the genital secretions of patients suffering from the disease. Antioxidants can therefore play an essential role in the treatment of chronic bacterial and non-bacterial prostatitis; in the case of bacterial inflammation, they can be associated with antibiotic therapy. Moreover, due to their anti-inflammatory properties, antioxidants hinder the progression of inflammation and the possible development of prostate cancer.

The Anti-inflammatory Effects of Short Chain Fatty Acids on Lipopolysaccharide- or Tumor Necrosis Factor α-Stimulated Endothelial Cells via Activation of GPR41/43 and Inhibition of HDACs

Background and Aim: Previously, we found that short chain fatty acids (SCFA) inhibit LPS or TNFα-induced endothelial inflammatory responses and excessive vascular cell adhesion molecule-1 (VCAM-1) expression, two important steps in the development of atherosclerosis. However, the mechanisms involved are still unclear. We hypothesized that the effects of SCFA are associated with activation of G-protein coupled receptor 41/43 (GPR41/43) and/or inhibition of histone deacetylases (HDACs).

Methods: The expression and location of GPR41/43 and HDAC3 in human umbilical vein endothelial cells (HUVEC) were confirmed. HUVEC were pre-incubated with acetate, butyrate or propionate alone or in combination with GLPG0974 (GLPG, antagonist of GPR43) or β-hydroxybutyrate (SHB, antagonist of GPR41) and then exposed to LPS or TNFα. Interleukin (IL)-6 and IL-8 levels and VCAM-1 expression were measured. HDAC activity was measured after treatment with butyrate, propionate and trichostatin A (TSA, HDAC inhibitor). The peripheral blood mononuclear cell (PBMC) adhesive level was also determined after TSA treatment.

Results: GPR41/43 were expressed on the membrane of HUVEC and HDAC3 was located in cytoplasm and nucleus. The GLPG and/or SHB treatments restored the inhibitory effects of acetate on IL-6 and IL-8 production and the inhibitory effects of butyrate or propionate on IL-6 production, but not on IL-8. In contrast, GLPG and/or SHB treatments did not affect the inhibitory effects of butyrate or propionate on TNFα-induced VCAM-1 expression. TSA showed similar effects on IL-8 production and VCAM-1 expression as butyrate and propionate. In addition, TSA significantly inhibited the adhesion of PBMC to an endothelial monolayer.

Conclusion: Activation of GPR41/43 mediates the effects of acetate on IL-6 and IL-8 production and the effects of butyrate and propionate on IL-6 production. Furthermore, inhibition of HDACs mediates the effects of butyrate and propionate on IL-8 production, VCAM-1 expression, and PBMC adhesion to an endothelial monolayer. These data indicate the beneficial roles of SCFA in preventing vascular inflammation and relevant diseases by activation of GPR41/43 and inhibition of HDACs.

Fermented non-digestible fraction from combined nixtamalized corn (Zea mays L.)/cooked common bean (Phaseolus vulgaris L.) chips modulate anti-inflammatory markers on RAW 264.7 macrophages

Chronic non-communicable diseases (NCDs) are low-level inflammation processes affected by several factors including diet. It has been reported that mixed whole grain and legume consumption, e.g. corn and common bean, might be a beneficial combination due to its content of bioactive compounds. A considerable amount would be retained in the non-digestible fraction (NDF), reaching the colon, where microbiota produce short-chain fatty acids (SCFAs) and phenolic compounds (PC) with known anti-inflammatory effect. The aim of this study was to estimate the anti-inflammatory potential of fermented-NDF of corn-bean chips (FNDFC) in RAW 264.7 macrophages. After 24 h, FNDFC produced SCFAs (0.156-0.222 mmol/l), inhibited nitric oxide production > 80% and H₂O₂ > 30%, up-regulated anti-inflammatory cytokines (I-TAC, TIMP-1) > 2-fold, and produced angiostatic and protective factors against vascular/tissue damage, and amelioration of tumor necrosis factor signalling and inflammatory bowel disease. These results confirm the anti-inflammatory potential derived from healthy corn-bean chips.

Alkylated resveratrol prodrugs and metabolites as potential therapeutics for neurodegenerative diseases

Resveratrol is a naturally occurring stilbene which has shown promising results as treatment for several neurodegenerative diseases. However, its application is limited due to its low efficacy and bioavailability. Here, we have designed and synthesized alkylated resveratrol prodrugs combining structural modification to improve antioxidant and anti-inflammatory properties and the preparation of prodrugs to extend drug bioavailability. For comparison we also studied resveratrol prodrugs and alkylated resveratrol derivatives. Methylated and butylated resveratrol derivatives showed the best in vitro neuroprotective and anti-inflammatory activity. The glucosyl- and glucosyl-acyl- prodrugs of these derivatives showed lower toxicity on zebra fish embryo. When neuroprotection was examined on pentylenetetrazole challenged zebra fish, they were capable of reverting neuronal damage but to a lower extent than resveratrol. Nevertheless, 3-O-(6'-O-octanoyl)-β-d-glucopyranoside resveratrol (compound 8) recovered AChE activity over 100% whereas resveratrol only up to 92%. In a 3-nitropropionic acid mice model of Huntington's disease, resveratrol derivative 8 delayed the onset and reduced the severity of HD-like symptoms, by improving locomotor activity and protecting against weight loss. Its effects involved an equal antioxidant but better anti-inflammatory profile than resveratrol as shown by SOD2 expression in brain tissue and circulating levels of IL-6 (11 vs 18 pg/mL), respectively. Finally, the octanoyl chain in compound 8 could be playing a role in inflammation and neuronal development indicating it could be acting as a double-drug, instead of as a prodrug.

Diet as a Therapeutic Option for Adult Inflammatory Bowel Disease

There are many mechanisms to explain how food may drive and ameliorate inflammation. Although there are no consistent macronutrient associations inflammatory bowel disease (IBD) development, many exclusion diets have been described: IgG-4 guided exclusion diet; semivegetarian diet; low-fat, fiber-limited exclusion diet; Paleolithic diet; Maker's diet; vegan diet; Life without Bread diet; exclusive enteral nutrition (EEN), the Specific Carbohydrate Diet (SCD) and the low FODMAP diet. The literature on diet and IBD is reviewed with a particular focus on EEN, SCD, and low FODMAP diets. Lessons learned from the existing observations and strengths and shortcomings of existing data are presented.

HDAC1 triggers the proliferation and migration of breast cancer cells via upregulation of interleukin-8

Targeted inhibition of histone deacetylase (HDAC) is one of the potent anticancer therapy approaches. Our data showed that mRNA and protein levels of HDAC1 in breast cancer cells were greater than that in normal fibroblast 3T3 cells and normal epithelial breast MCF10A cells. The mRNA levels of HDAC1 in 75% of breast cancer tissues (18/24) were greater than that in their corresponding adjacent normal tissues. Knockdown of HDAC1 by specific siRNAs can suppress the proliferation and migration of breast cancer cells and inhibit the expression of interleukin-8 (IL-8), while not IL-6. While recombinant IL-8 (rIL-8) can attenuate the suppression effects of si-HDAC1 on the proliferation and migration of breast cancer cells. HDAC1 can positively regulate the transcription and promoter activities of IL-8. While NF-κB and MAPK, two important signals responsible for the transcription of IL-8, did not mediate HDAC1 regulated IL-8 expression. The expression and nuclear translocation of Snail were increased in HDAC1 over expressed breast cancer cells. Targeted inhibition of Snail can attenuate HDAC1 over expression induced cell proliferation and migration. Collectively, our data showed that HDAC1 can trigger the proliferation and migration of breast cancer cells via activation of Snail/IL-8 signals.

Sodium Octanoate Modulates the Innate Immune Response of Bovine Mammary Epithelial Cells through the TLR2/P38/JNK/ERK1/2 Pathway: Implications during Staphylococcus aureus Internalization

Bovine mammary epithelial cells (bMECs) contribute to mammary gland defense against invading pathogens, such as Staphylococcus aureus (intracellular facultative), which is recognized by TLR2. In a previous report, we showed that sodium octanoate [NaO, a medium chain fatty acid (C8)] induces (0.25 mM) or inhibits (1 mM) S. aureus internalization into bMECs and differentially regulates the innate immune response (IIR). However, the molecular mechanisms have not been described, which was the aim of this study. The results showed that α5β1 integrin membrane abundance (MA) was increased in 0.25 mM NaO-treated cells, but TLR2 or CD36 MA was not modified. When these receptors were blocked individually, 0.25 mM NaO-increased S. aureus internalization was notably reduced. Interestingly, in this condition, the IIR of the bMECs was impaired because MAPK (p38, JNK, and ERK1/2) phosphorylation and the activation of transcription factors related to these pathways were decreased. In addition, the 1 mM NaO treatment induced TLR2 MA, but neither the integrin nor CD36 MA was modified. The reduction in S. aureus internalization induced by 1 mM NaO was increased further when TLR2 was blocked. In addition, the phosphorylation levels of the MAPKs increased, and 13 transcriptional factors related to the IIR were slightly activated (CBF, CDP, c-Myb, AP-1, Ets-1/Pea-3, FAST-1, GAS/ISRE, AP-2, NFAT-1, OCT-1, RAR/DR-5, RXR/DR-1, and Stat-3). Moreover, the 1 mM NaO treatment up-regulated gene expression of IL-8 and RANTES and secretion of IL-1β. Notably, when 1 mM NaO-treated bMECs were challenged with S. aureus, the gene expression of IL-8 and IL-10 increased, while IL-1β secretion was reduced. In conclusion, our results showed that α5β1 integrin, TLR2 and CD36 are involved in 0.25 mM NaO-increased S. aureus internalization in bMECs. In addition, 1 mM NaO activates bMECs via the TLR2 signaling pathways (p38, JNK, and ERK1/2), which improves IIR before S. aureus invasion. Additionally, NaO (1 mM) might exert anti-inflammatory effects after bacterial internalization.

Effects of medium-chain fatty acids on the structure and immune response of IPEC-J2 cells

Medium-chain fatty acids (MCFAs) have been suggested as an alternative to the use of antibiotics in animal nutrition with promising results. First, we studied the sensitivity of Salmonella Enteritidis and an enteropathogenic Escherichia coli strain against caprylic (C8), capric (C10) and lauric (C12) acids. A porcine in vitro model using the porcine cell line IPEC-J2 was used to test the effects of MCFAs on structural and immunological traits without and with a concomitant challenge with E. coli or S. Enteritidis. The three MCFAs exerted an inhibitory effect on bacterial growth, stronger for C12 than C8 or C10, S. Enteritidis being more sensitive than the E. coli strain. Flow cytometry showed a numeric concentration dependent increase in the adhesion of E. coli or S. Enteritidis to IPEC-J2 cells. Measurement of transepithelial electrical resistance after bacterial challenge showed negative effects of all MCFAs on IPEC-J2 cells at the highest concentrations. Immune parameters were affected by C8, since a concentration dependent effect starting at 5 mM was observed for mRNA expression of IL-6 and TLR-4 (up-regulated) and IL-8 (down-regulated). TLR-4 was up-regulated with C10 at 2 and 5 mM. The three MCFAs affected also the epithelial morphology through down-regulation of Occludin and up-regulation of Claudin-4 expression. In conclusion, the three MCFAs under study influenced bacterial growth rates and modified the gene expression to a different degree in the cell line IPEC-J2 but the effect on the morphological structure and response of the cells after bacterial challenge could not be assessed. Although these tests show a prior estimation of MCFAs effects in intestinal epithelium, in vivo confirmation is still needed.

Cinnamomum camphora Seed Kernel Oil Ameliorates Oxidative Stress and Inflammation in Diet-Induced Obese Rats

Cinnamomum camphora seed kernel oil (CCSKO) was found to reduce body fat deposition and improve blood lipid in both healthy and obese rats. The study was aimed to investigate the antioxidative stress and anti-inflammatory effects of CCSKO in high-fat-diet-induced obese rats. The obese rats were treated with CCSKO, lard, and soybean oil, respectively, for 12 wk. The level of total antioxidant capacity (T-AOC), activities of superoxide dismutase (SOD), glutathione peroxidase, and catalase, and levels of malondialdehyde (MDA), tumor necrosis factor (TNF)-α, peroxisome proliferator-activated receptor (PPAR)-γ, interleukin (IL)-6, and P65 were compared among CCSKO, lard, and soybean oil groups. Our results showed that the level of T-AOC and activities of SOD and catalase were significantly increased and the level of MDA was significantly decreased in CCSKO group. In addition, CCSKO treatment reduced the activities of serum glutamic oxaloacetic transaminase and glutamate-pyruvate transaminase, and levels of serum TNF-α, IL-6, and P65 through raising the level of PPAR-γ. In conclusion, CCSKO has, for the first time, been found to ameliorate oxidative stress and inflammation in high-fat-diet-induced obese rats.

Medium-chain triglyceride ameliorates insulin resistance and inflammation in high fat diet-induced obese mice

PURPOSE

The aim of the present study was to investigate the in vivo effects of dietary medium-chain triglyceride (MCT) on inflammation and insulin resistance as well as the underlying potential molecular mechanisms in high fat diet-induced obese mice.

METHODS

Male C57BL/6J mice (n = 24) were fed one of the following three diets for a period of 12 weeks: (1) a modified AIN-76 diet with 5 % corn oil (normal diet); (2) a high-fat control diet (17 % w/w lard and 3 % w/w corn oil, HFC); (3) an isocaloric high-fat diet supplemented with MCT (17 % w/w MCT and 3 % w/w corn oil, HF-MCT). Glucose metabolism was evaluated by fasting blood glucose levels and intraperitoneal glucose tolerance test. Insulin sensitivity was evaluated by fasting serum insulin levels and the index of homeostasis model assessment-insulin resistance. The levels of serum interleukin-6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor-α were measured by ELISA, and hepatic activation of nuclear factor κB (NF-κB) and mitogen-activated protein kinase (MAPK) pathways was determined using western blot analysis.

RESULTS

Compared to HFC diet, consumption of HF-MCT did not induce body weight gain and white adipose tissue accumulation in mice. HFC-induced increases in serum fasting glucose and insulin levels as well as glucose intolerance were prevented by HF-MCT diet. Meanwhile, HF-MCT resulted in significantly lower serum IL-6 level and higher IL-10 level, and lower expression levels of inducible nitric oxide synthase and cyclooxygenase-2 protein in liver tissues when compared to HFC. In addition, HF-MCT attenuated HFC-triggered hepatic activation of NF-κB and p38 MAPK.

CONCLUSIONS

Our study demonstrated that MCT was efficacious in suppressing body fat accumulation, insulin resistance, inflammatory response, and NF-κB and p38 MAPK activation in high fat diet-fed mice. These data suggest that MCT may exert beneficial effects against high fat diet-induced insulin resistance and inflammation.

Combinatorial effects of diet and genetics on inflammatory bowel disease pathogenesis

Inflammatory bowel disease (IBD) encompasses a group of disorders affecting the gastrointestinal tract characterized by acute and chronic inflammation. These are complex and multifactorial disorders that arise in part from a genetic predisposition. However, the increasing incidence of IBD in developing countries suggests that environmental factors, such as diet, are also critical components of disease susceptibility. Evidence suggests that consumption of a Western diet, enriched with saturated fat, refined carbohydrates, and food additives, is associated with increased IBD risk. Dietary components, such as omega-6 fatty acids, long-chain fatty acids, protein, and digestible carbohydrates, may contribute to IBD pathogenesis through altering intestinal microbiota, increasing intestinal permeability, and promoting inflammation; whereas omega-3 fatty acids, medium chain triglycerides, and nondigestible carbohydrates improve these parameters and intestinal health. However, the limited amount of prospective studies, small sample sizes, and the heterogeneity of disease subtype result in inconsistencies between studies and difficulty in conclusively determining the specific effects of diet on intestinal homeostasis. There are no standard clinical dietary recommendations for patients with IBD. However, exclusionary diet interventions have shown some efficacy in relieving symptoms or inducing remission, suggesting more research is needed to fully understand how diet influences disease behavior or combines with other IBD risk factors to promote disease. This review focuses on the associations of various dietary components and IBD risk in clinical studies and genetically susceptible IBD models.

Effects of sodium octanoate on innate immune response of mammary epithelial cells during Staphylococcus aureus internalization

Bovine mammary epithelial cells (bMECs) are capable of initiating an innate immune response to invading bacteria. Short chain fatty acids can reduce Staphylococcus aureus internalization into bMEC, but it has not been evaluated if octanoic acid (sodium octanoate, NaO), a medium chain fatty acid (MCFA), has similar effects. In this study we determined the effect of NaO on S. aureus internalization into bMEC and on the modulation of innate immune elements. NaO (0.25–2 mM) did not affect S. aureus growth and bMEC viability, but it differentially modulated bacterial internalization into bMEC, which was induced at 0.25–0.5 mM (~60%) but inhibited at 1-2 mM (~40%). Also, bMEC showed a basal expression of all the innate immune genes evaluated, which were induced by S. aureus. NaO induced BNBD4, LAP, and BNBD10 mRNA expression, but BNBD5 and TNF-α were inhibited. Additionally, the pretreatment of bMEC with NaO inhibited the mRNA expression induction generated by bacteria which coincides with the increase in internalization; only TAP and BNDB10 showed an increase in their expression; it coincides with the greatest effect on the reduction of bacterial internalization. In conclusion, NaO exerts a dual effect on S. aureus internalization in bMEC and modulates elements of innate immune response.

Dietary medium-chain triglycerides promote oral allergic sensitization and orally induced anaphylaxis to peanut protein in mice

BACKGROUND

The prevalence of peanut allergies is increasing. Peanuts and many other allergen sources contain significant amounts of triglycerides, which affect absorption of antigens but have unknown effects on sensitization and anaphylaxis. We recently reported that dietary medium-chain triglycerides (MCTs), which bypass mesenteric lymph and directly enter portal blood, reduce intestinal antigen absorption into blood compared with long-chain triglycerides (LCTs), which stimulate mesenteric lymph flow and are absorbed in chylomicrons through mesenteric lymph.

OBJECTIVE

We sought to test how dietary MCTs affect food allergy.

METHODS

C3H/HeJ mice were fed peanut butter protein in MCT, LCT (peanut oil), or LCT plus an inhibitor of chylomicron formation (Pluronic L81). Peanut-specific antibodies in plasma, responses of the mice to antigen challenges, and intestinal epithelial cytokine expression were subsequently measured.

RESULTS

MCT suppressed antigen absorption into blood but stimulated absorption into Peyer patches. A single gavage of peanut protein with MCT, as well as prolonged feeding in MCT-based diets, caused spontaneous allergic sensitization. MCT-sensitized mice experienced IgG-dependent anaphylaxis on systemic challenge and IgE-dependent anaphylaxis on oral challenge. MCT feeding stimulated jejunal-epithelial thymic stromal lymphopoietin, Il25, and Il33 expression compared with that seen after LCT feeding and promoted T(H)2 cytokine responses in splenocytes. Moreover, oral challenges of sensitized mice with antigen in MCT significantly aggravated anaphylaxis compared with challenges with the LCT. Importantly, the effects of MCTs could be mimicked by adding Pluronic L81 to LCTs, and in vitro assays indicated that chylomicrons prevent basophil activation.

CONCLUSION

Dietary MCTs promote allergic sensitization and anaphylaxis by affecting antigen absorption and availability and by stimulating T(H)2 responses.

PGE2 induces interleukin-8 derepression in human astrocytoma through coordinated DNA demethylation and histone hyperacetylation

We have recently reported that in astrocytoma cells the expression of interleukin-8 (IL-8) is upregulated by prostaglandin E2 (PGE2). Unfortunately, the exact mechanism by which this happens has not been clarified yet. Here, we have investigated whether IL-8 activation by PGE2 involves changes in DNA methylation and/or histone modifications in 46 astrocytoma specimens, two astrocytoma cell lines and normal astrocytic cells. The DNA methylation status of the IL-8 promoter was analyzed by bisulphite sequencing and by methylation DNA immunoprecipitation analysis. The involvement of DNA methyltransferases (DNMTs) and histone deacetylases (HDACs), as well as histone acetylation levels, was assayed by chromatin immunoprecipitation. IL-8 expression at promoter, mRNA and protein level was explored by transfection, real-time PCR and enzyme immunoassay experiments in cells untreated or treated with PGE2, 5-aza-2'-deoxycytidine (5-aza-dC) and HDAC inhibitors, alone or in combination. EMSA was performed with crude cell extracts or recombinant protein. We observed that PGE2 induced IL-8 activation through: (1) demethylation of the single CpG site 5 located at position -83 within the binding region for CEBP-β in the IL-8 promoter; (2) C/EBP-β and p300 co-activator recruitment; (3) H3 acetylation enhancement and (4) reduction in DNMT1, DNMT3a, HDAC2 and HDAC3 association to CpG site 5 region. Treatment with 5-aza-dC or HDAC inhibitors of class I HDACs strengthened either basal or PGE2-mediated IL-8 expression. These findings have elucidated an orchestrated mechanism triggered by PGE2 whereby concurrent association of site-specific demethylation and histone H3 hyperacetylation resulted in derepression of IL-8 gene expression in human astrocytoma.

Nutrient signaling: evolutionary origins of the immune-modulating effects of dietary fat

Many dietary fatty acids (FA) have potent effects on inflammation, which is not only energetically costly, but also contributes to a range of chronic diseases. This presents an evolutionary paradox: Why should the host initiate a costly and damaging response to commonly encountered nutrients? We propose that the immune system has evolved a capacity to modify expenditure on inflammation to compensate for the effects of dietary FA on gut microorganisms. In a comprehensive literature review, we show that the body preferentially upregulates inflammation in response to saturated FA that promote harmful microbes. In contrast, the host opften reduces inflammation in response to the many unsaturated FA with antimicrobial properties. Our model is supported by contrasts involving shorter-chain FA and omega-3 FA, but with less consistent evidence for trans fats, which are a recent addition to the human diet. Our findings support the idea that the vertebrate immune system has evolved a capacity to detect diet-driven shipfts in the composition of gut microbiota from the profile of FA consumed and to calibrate the costs of inflammation in response to these cues. We conclude by extending the nutrient signaling model to other nutrients, and consider implications for drug discovery and public health.

Nutritional and physiological role of medium-chain triglycerides and medium-chain fatty acids in piglets

Medium-chain fatty acids (MCFAs) are found at higher levels in milk lipids of many animal species and in the oil fraction of several plants, including coconuts, palm kernels and certainCupheaspecies. Medium-chain triglycerides (MCTs) and fatty acids are efficiently absorbed and metabolized and are therefore used for piglet nutrition. They may provide instant energy and also have physiological benefits beyond their energetic value contributing to several findings of improved performance in piglet-feeding trials. MCTs are effectively hydrolyzed by gastric and pancreatic lipases in the newborn and suckling young, allowing rapid provision of energy for both enterocytes and intermediary hepatic metabolism. MCFAs affect the composition of the intestinal microbiota and have inhibitory effects on bacterial concentrations in the digesta, mainly onSalmonellaand coliforms. However, most studies have been performedin vitroup to now andin vivodata in pigs are still scarce. Effects on the gut-associated and general immune function have been described in several animal species, but they have been less studied in pigs. The addition of up to 8% of a non-esterified MCFA mixture in feed has been described, but due to the sensory properties this can have a negative impact on feed intake. This may be overcome by using MCTs, allowing dietary inclusion rates up to 15%. Feeding sows with diets containing 15% MCTs resulted in a lower mortality of newborns and better development, particularly of underweight piglets. In conclusion, MCFAs and MCTs offer advantages for the improvement of energy supply and performance of piglets and may stabilize the intestinal microbiota, expanding the spectrum of feed additives supporting piglet health in the post-weaning period.

Preventive oral treatment with resveratrol pro-prodrugs drastically reduce colon inflammation in rodents

There is no pharmaceutical or definitive surgical cure for inflammatory bowel diseases (IBDs). The naturally occurring polyphenol resveratrol exerts anti-inflammatory properties. However, its rapid metabolism diminishes its effectiveness in the colon. The design of prodrugs to targeting active molecules to the colon provides an opportunity for therapy of IBDs. Herein we explore the efficacy of different resveratrol prodrugs and pro-prodrugs to ameliorate colon inflammation in the murine dextran sulfate sodium (DSS) model. Mice fed with a very low dose (equivalent to 10 mg for a 70 kg-person) of either resveratrol-3-O-(6'-O-butanoyl)-β-D-glucopyranoside (6) or resveratrol-3-O-(6'-O-octanoyl)-β-D-glucopyranoside (7) did not develop colitis symptoms and improved 6-fold the disease activity index (DAI) compared to resveratrol. Our results indicate that these pro-prodrugs exerted a dual effect: (1) they prevented the rapid metabolism of resveratrol and delivered higher quantities of resveratrol to the colon and (2) they reduced mucosal barrier imbalance and prevented diarrhea, which consequently facilitated the action of the delivered resveratrol in the colon mucosa.

Statins control oxidized LDL-mediated histone modifications and gene expression in cultured human endothelial cells

OBJECTIVE

Activation of the endothelium by oxidized low-density lipoprotein (oxLDL) has been implicated in the development of atherosclerosis. Histone modifications impact on the transcriptional activity state of genes. We tested the hypothesis that oxLDL-induced inflammatory gene expression is regulated by histone modifications and experienced the effect of statins on these alterations.

METHODS AND RESULTS

OxLDL-related interleukin-8 (IL-8) and monocyte-chemoattractant protein-1 (MCP-1) secretion in endothelial cells was reduced by statins but enhanced by histone deacetylase inhibitors. OxLDL induced lectin-like oxidized LDL receptor-1 (LOX-1) and extracellular regulated kinases (ERK1/2)-dependent acetylation of histone H3 and H4 as well as phosphorylation of histone H3, both globally and on the promoters of il8 and mcp1. Pretreatment of oxLDL-exposed cells with statins reduced the above mentioned histone modification, as well as recruitment of CREB binding protein (CBP) 300, NF-kappaB, and of RNA polymerase II but prevented loss of binding of histone deacetylase (HDAC)-1 and -2 at the il8 and mcp1 gene promoters. OxLDL reduced HDAC1 and 2 expression, and statins partly restored global HDAC-activity. Statin-related effects were reverted with mevalonate. In situ experiments indicated decreased expression of HDAC2 in endothelial cells in atherosclerotic plaques of human coronary arteries.

CONCLUSIONS

Histone modifications seem to play an important role in atherosclerosis.

Histone deacetylase inhibitors suppress interleukin-1beta-induced nitric oxide and prostaglandin E2 production in human chondrocytes

OBJECTIVE

Overproduction of nitric oxide (NO) and prostaglandin E(2) (PGE(2)) plays an important role in the pathogenesis of osteoarthritis (OA). In the present study, we determined the effect of trichostatin A (TSA) and butyric acid (BA), two histone deacetylase (HDAC) inhibitors, on NO and PGE(2) synthesis, inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 expression, and nuclear factor (NF)-kappaB DNA-binding activity, in interleukin-1beta (IL-1)-stimulated human OA chondrocytes, and on IL-1-induced proteoglycan degradation in cartilage explants.

METHODS

Chondrocytes were stimulated with IL-1 in the absence or presence of increasing concentrations of TSA or BA. The production of NO and PGE(2) was evaluated using Griess reagent and an enzyme immunoassay, respectively. The expression of iNOS and COX-2 proteins and mRNAs was evaluated using Western blotting and real-time reverse transcriptase-polymerase chain reaction (RT-PCR), respectively. Proteoglycan degradation was measured with dimethymethylene blue assay. Electrophoretic mobility shift assay (EMSA) was utilized to analyze the DNA-binding activity of NF-kappaB.

RESULTS

HDAC inhibition with TSA or BA resulted in a dose-dependent inhibition of IL-1-induced NO and PGE(2) production. IL-17- and tumor necrosis factor-alpha (TNF-alpha)-induced NO and PGE(2) production was also inhibited by TSA and BA. This inhibition correlated with the suppression of iNOS and COX-2 protein and mRNA expression. TSA and BA also prevented IL-1-induced proteoglycan release from cartilage explants. Finally, we demonstrate that the DNA-binding activity of NF-kappaB, was induced by IL-1, but was not affected by treatment with HDAC inhibitors.

CONCLUSIONS

These data indicate that HDAC inhibitors suppressed IL-1-induced NO and PGE(2) synthesis, iNOS and COX-2 expression, as well as proteoglycan degradation. The suppressive effect of HDAC inhibitors is not due to impaired DNA-binding activity of NF-kappaB. These findings also suggest that HDAC inhibitors may be of potential therapeutic value in the treatment of OA.

Interleukin-8 expression is regulated by histone deacetylases through the nuclear factor-kappaB pathway in breast cancer

We have reported recently that the chemokine interleukin 8 (IL-8)/CXCL8 was overexpressed in invasive estrogen receptor (ERalpha)-negative breast cancer cells compared with ERalpha-positive breast cancer cells. We now demonstrate that histone deacetylases (HDACs) play an essential role in the regulation of IL-8 gene expression in ERalpha-positive MCF-7 breast cancer cells. Treatment of MCF-7 cells with the HDAC inhibitor trichostatin A (TSA) led to a strong up-regulation of IL-8 protein and RNA levels in MCF-7 cells. The up-regulation of IL-8 in MCF-7 cells was time- and concentration-dependent. Moreover, run-on and transfection experiments demonstrated that IL-8 induction by HDAC inhibitors was transcriptional and involved mainly the nuclear factor-kappaB (NF-kappaB) site of the IL-8 promoter. These observations are corroborated by an up-regulation of NF-kappaB activity in MCF-7 cells in the presence of TSA. In addition, blocking NF-kappaB pathway by adenoviral delivery of a dominant-negative IkappaBorIkappaB kinase complex 2 (IKK2) mutant abolished IL-8 gene induction by histone deacetylase inhibitors. HDAC inhibitors triggered IKK phosphorylation and up-regulated p65 nuclear translocation, although they decreased the protein levels of IkappaBalpha, which accounts for NF-kappaB activation. TSA increased binding of acetylated histone 3 to the IL-8 gene promoter. In summary, our results demonstrate that NF-kappaB pathway repression by HDAC is responsible for the low expression of IL-8 in ERalpha-positive breast cancer cells.

Simvastatin Reduces Chlamydophila pneumoniae –Mediated Histone Modifications and Gene Expression in Cultured Human Endothelial Cells

Inflammatory activation of the endothelium by Chlamydophila pneumoniae infection has been implicated in the development of chronic vascular lesions and coronary heart disease by seroepidemiological and animal studies. We tested the hypothesis that C pneumoniae induced inflammatory gene expression is regulated by Rho-GTPase–related histone modifications. C pneumoniae infection induced the liberation of proinflammatory interleukin-6, interleukin-8, granulocyte colony-stimulating factor, macrophage inflammatory protein-1β, granulocyte/macrophage colony-stimulating factor, and interferon-γ by human endothelial cells. Cytokine secretion was reduced by simvastatin and the specific Rac1 inhibitor NSC23766 but was synergistically enhanced by inhibitors of histone deacetylases trichostatin A and suberoylanilide hydroxamic acid. Infection of endothelial cells with viable C pneumoniae , but not exposure to heat-inactivated C pneumoniae or infection with C trachomatis , induced acetylation of histone H4 and phosphorylation and acetylation of histone H3. Pretreatment of C pneumoniae –infected cells with simvastatin or NSC23766 reduced global histone modifications as well as specific modifications at the il8 gene promoter, as shown by chromatin immunoprecipitation. Reduced recruitment of nuclear factor κB p65/RelA as well as of RNA polymerase II was observed in statin-treated cells. Taken together, Rac1-mediated histone modifications seem to play an important role in C pneumoniae –induced cytokine production by human endothelial cells.

Suppression of lipopolysaccharide- and tumour necrosis factor-alpha-induced interleukin (IL)-8 expression by glucocorticoids involves changes in IL-8 promoter acetylation

There is accumulating evidence that the transrepressional effect of glucocorticoids in down-regulating proinflammatory gene expression might be regulated by an action on histone acetylation. To investigate this, we studied the effect of two glucocorticoids (dexamethasone and triamcinolone acetonide) on reducing lipopolysaccharide (LPS)- and tumour necrosis factor (TNF)-alpha-induced interleukin (IL)-8 release in a monocytic cell line and two lymphocytic cell lines (HUT-78 and Jurkat). The effect of the histone deacetylase inhibitor trichostatin A (TSA) on LPS- and TNF-alpha-induced IL-8 release and its repression by glucocorticoids was also examined. LPS and TNF-alpha induced IL-8 release in all three cell lines and this induction was inhibited by both dexamethasone and triamcinolone. Pretreatment of cells with TSA enhanced basal and LPS- and TNFalpha-stimulated IL-8 release in all three cell lines. TSA also attenuated the inhibitory effect of glucocorticoids on stimulated IL-8 release. Chromatin immunoprecipitation assays confirmed that LPS and TNF-alpha enhanced histone acetylation at the IL-8 promoter and that this was inhibited by triamcinolone in all three cell types. Changes in histone acetylation at the IL-8 are important in its regulation by proinflammatory and anti-inflammatory agents, and modulation of this activity may have therapeutic potential in inflammatory conditions.

Listeria monocytogenes induced Rac1-dependent signal transduction in endothelial cells

Infection of endothelial cells by Listeria monocytogenes is an essential step in the pathogenesis of listeriosis. Small GTPases of the Rho family act as molecular switches in signal transduction. We tested the hypothesis that Rho GTPases contribute to the regulation of cytokine expression following L. monocytogenes infection. L. monocytogenes induced release of distinct CC and CXC, as well as Th1 and Th2 cytokines and growth factors by endothelial cells and activated RhoA and Rac1. Inhibition of Rac1 by inhibitor Nsc23766 reduced cytokine expression, and slightly yet significantly the uptake of bacteria. Blocking of Rho proteins by Clostridium difficile toxin B-10463 (TcdB) reduced Listeria-dependent cytokine expression, whereas activating Rho proteins by Escherichia coli CNF1 increased it. We analyzed regulation of IL-8 expression in more detail: Listeria-induced IL-8 release was reduced by inhibition of RhoA, Rac1 and Cdc42 (TcdB) or Rac1 while blocking of RhoA/B/C by Clostridium limosum C3 fusion toxin (C3FT) or Rho kinase by Y27632 reduced cytokine expression only slightly. Activation of RhoA, Rac1 and Cdc42 (CNF1), but not of RhoA alone (CNF(Y)), enhanced Listeria-dependent IL-8 release significantly. Furthermore, inhibition of RhoA, Rac1 and Cdc42 (TcdB) and Rac1 (Nsc23766), but not of RhoA (C3FT) reduced Listeria-related recruitment of NF-kappaB/p65 and RNA polymerase II to the il8 promoter, as well as acetylation of histone H4 and Ser10/Lys14-phosphorylation/acetylation of histone H3 at the il8 gene promoter in HUVEC. In conclusion, Rac1 contributed to L. monocytogenes-induced cytokine expression by human endothelial cells.

Intracellular bacteria differentially regulated endothelial cytokine release by MAPK-dependent histone modification

Epigenetic histone modifications contribute to the regulation of eukaryotic gene transcription. The role of epigenetic regulation in immunity to intracellular pathogens is poorly understood. We tested the hypothesis that epigenetic histone modifications influence cytokine expression by intracellular bacteria. Intracellular Listeria monocytogenes, but not noninvasive Listeria innocua, induced release of distinct CC and CXC chemokines, as well as Th1 and Th2 cytokines and growth factors by endothelial cells. Cytokine expression was in part dependent on p38 MAPK and MEK1. We analyzed global histone modification and modifications in detail at the gene promoter of IL-8, which depended on both kinase pathways, and of IFN-gamma, which was not blocked by kinase inhibition. Intracellular Listeria induced time-dependent acetylation (lysine 8) of histone H4 and phosphorylation/acetylation (serine 10/lysine 14) of histone H3 globally and at the il8 promoter in HUVEC, as well as recruitment of the histone acetylase CREB-binding protein. Inhibitors of p38 MAPK and MEK1 reduced lysine 8 acetylation of histone H4 and serine 10/lysine 14 phosphorylation/acetylation of histone H3 in Listeria-infected endothelial cells and disappearance of histone deacetylase 1 at the il8 promoter in HUVEC. In contrast, IFN-gamma gene transcription was activated by Listeria monocytogenes independent of p38 MAPK and MEK1, and histone phosphorylation/acetylation remained unchanged in infected cells at the IFN-gamma promoter. Specific inhibition of histone deacetylases by trichostatin A increased Listeria-induced expression of IL-8, but not of IFN-gamma, underlining the specific physiological impact of histone acetylation. In conclusion, MAPK-dependent epigenetic modifications differentially contributed to L. monocytogenes-induced cytokine expression by human endothelial cells.

Redox modulation of chromatin remodeling: impact on histone acetylation and deacetylation, NF-kappaB and pro-inflammatory gene expression

Reactive oxygen species (ROS), either directly or via the formation of lipid peroxidation products, such as 4-hydroxy-2-nonenal, acrolein and F2-isoprostanes, may play a role in enhancing inflammation through the activation and phosphorylation of stress kinases (JNK, ERK, p38) and redox-sensitive transcription factors such as NF-kappaB and AP-1. This increases the expression of genes regulating a battery of distinct pro-inflammatory mediators. Acetylation by histone acetyltransferase (HAT) of specific lysine residues on the N-terminal tail of core histones, results in uncoiling of the DNA and increased accessibility to transcription factor binding. In contrast, histone deacetylation by histone deacetylase (HDAC) represses gene transcription by promoting DNA winding thereby limiting access to transcription factors. Oxidative stress activates NF-kappaB resulting in expression of pro-inflammatory mediators through the activation of intrinsic HAT activity on co-activator molecules. In addition, oxidative stress also inhibits HDAC activity and in doing so enhances inflammatory gene expression which leads to a chronic inflammatory response. Oxidative stress can also increase complex formation between the co-activator CBP/p300 and the p65 subunit of NF-kappaB suggesting a further role of oxidative stress in chromatin remodeling. The antioxidant and/or anti-inflammatory effects of thiol molecules (glutathione, N-acetyl-L-cysteine and N-acystelyn), dietary polyphenols (curcumin-diferuloylmethane and resveratrol), the bronchodilator theophylline and glucocorticoids have all been shown to play a role in either controlling NF-kappaB activation or chromatin remodeling through modulation of HDAC activity and subsequently inflammatory gene expression in lung epithelial cells. Thus, oxidative stress regulates both signal transduction and chromatin remodeling which in turn impacts on pro-inflammatory responses in the lungs.

Oxidative stress and calcium signaling in the adverse effects of environmental particles (PM10)

This review focuses on the potential role that oxidative stress plays in the adverse effects of PM(10). The central hypothesis is that the ability of PM(10) to cause oxidative stress underlies the association between increased exposure to PM(10) and both exacerbations of lung disease and lung cancer. Pulmonary inflammation may also underlie the cardiovascular effects seen following increased PM(10), although the mechanisms of the cardiovascular effects of PM(10) are not well understood. PM(10) is a complex mix of various particle types and several of the components of PM(10) are likely to be involved in the induction of oxidative stress. The most likely of these are transition metals, ultrafine particle surfaces, and organic compounds. In support of this hypothesis, oxidative stress arising from PM(10) has been shown to activate a number of redox-responsive signaling pathways in lung target cells. These pathways are involved in expression of genes that play a role in responses relevant to inflammation and pathological change, including MAPKs, NF-kappaB, AP-1, and histone acetylation. Oxidative stress from particles is also likely to play an important role in the carcinogenic effects associated with PM(10) and hydroxyl radicals from PM(10) cause DNA damage in vitro.