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At least 865 records · Page 48Linked to original sources
PubMed2005

Butyrate blocks interferon-gamma-inducible protein-10 release in human intestinal subepithelial myofibroblasts.

BACKGROUND: Interferon (IFN)-gamma-inducible protein (IP)-10 is a chemoattractant for CXCR 3-expressing T lymphocytes and monocytes. IP-10 has been reported to mediate chronic inflammation such as that in inflammatory bowel disease (IBD). However, the local secretion of IP-10 in the intestine remains unclear. In this study, we investigated IP-10 secretion in human colonic subepithelial myofibroblasts (SEMFs). METHODS: IP-10 secretion was determined by enzyme-linked immunosorbent assay (ELISA), and IP-10 mRNA expression was evaluated by Northern blotting. RESULTS: Interleukin (IL)-10 mRNA was not detected in unstimulated SEMFs. Interferon (IFN)-gamma strongly induced IP-10 mRNA expression. Tumor necrosis factor (TNF)-alpha also stimulated IP-10 mRNA expression, but this was much weaker than that induced by IFN-gamma. The effects of IFN-gamma and TNF-alpha were detected in a dose- and time-dependent manner. These responses were also observed at the protein levels. The IFN-gamma-induced IP-10 secretion was not affected by acetate or propionate, but was significantly reduced by butyrate. Trichostatin A, a specific inhibitor of histone deacetylase, also blocked the IFN-gamma- and TNF-alpha-induced IP-10 mRNA expression, but the effects of trichostatin A were weaker than those of butyrate. The inhibitory effect of butyrate on IFN-gamma-induced IP-10 release was not associated with STAT (signaling transducer and activator of transcription)-1alpha activation. CONCLUSIONS: We demonstrated that human colonic SEMFs are the local site for the secretion IP-10. The regulation of IP-10 release by IFN-gamma and butyrate may play an important role in controlling chronic mucosal inflammation in pathological entities such as IBD.

Base Sequence↗
PubMed2006

Relation between phylogenetic position, lipid metabolism and butyrate production by different Butyrivibrio-like bacteria from the rumen.

The Butyrivibrio group comprises Butyrivibrio fibrisolvens and related Gram-positive bacteria isolated mainly from the rumen of cattle and sheep. The aim of this study was to investigate phenotypic characteristics that discriminate between different phylotypes. The phylogenetic position, derived from 16S rDNA sequence data, of 45 isolates from different species and different countries was compared with their fermentation products, mechanism of butyrate formation, lipid metabolism and sensitivity to growth inhibition by linoleic acid (LA). Three clear sub-groups were evident, both phylogenetically and metabolically. Group VA1 typified most Butyrivibrio and Pseudobutyrivibrio isolates, while Groups VA2 and SA comprised Butyrivibrio hungatei and Clostridium proteoclasticum, respectively. All produced butyrate but strains of group VA1 had a butyrate kinase activity <40 U (mg protein)(-1), while strains in groups VA2 and SA all exhibited activities >600 U (mg protein)(-1). The butyrate kinase gene was present in all VA2 and SA bacteria tested but not in strains of group VA1, all of which were positive for the butyryl-CoA CoA-transferase gene. None of the bacteria tested possessed both genes. Lipase activity, measured by tributyrin hydrolysis, was high in group VA2 and SA strains and low in Group VA1 strains. Only the SA group formed stearic acid from LA. Linoleate isomerase activity, on the other hand, did not correspond with phylogenetic position. Group VA1 bacteria all grew in the presence of 200 microg LA ml(-1), while members of Groups VA2 and SA were inhibited by lower concentrations, some as low as 5 microg ml(-1). This information provides strong links between phenotypic and phylogenetic properties of this group of clostridial cluster XIVa Gram-positive bacteria.

Animals↗
PubMed2005

Activation of CMV promoter-controlled glycosyltransferase and beta -galactosidase glycogenes by butyrate, tricostatin A, and 5-aza-2'-deoxycytidine.

Cytomegalovirus (CMV) immediate early promoter is a powerful promoter frequently used for driving the expression of transgenes in mammalian cells. However, this promoter gradually becomes silenced in stably transfected cells. We employed Chinese Hamster Ovary (CHO) and human pancreatic cancer (Panc 1) cells stably tansfected with three glycogenes driven by a CMV promoter to study the activation of silenced glycogenes. We found that butyrate, tricostatin A (TSA), and 5-aza-2'-deoxycytidine (5-Aza-dC) can activate these CMV-driven glycogenes. The increase in mRNA and protein of a glycogene occurred 8-10 h after butyrate treatment, suggesting an indirect effect of butyrate in the activation of the transgene. The enhanced expression of the trangenes by butyrate and TSA, known inhibitors of histone deacetylase, was independent of the transgene or cell type. However, the transgene can be activated by these two agents in only a fraction of the cells derived from a single clone, suggesting that inactivation of histone deacetylase can only partially explain silencing of the transgenes. Combination treatment of one or both agents with 5-Aza-dC, a known inhibitor of DNA methylase, resulted in a synergistic activation of the transgene, suggesting a cross-talk between histone acetylation and DNA demethylation. Understanding the mechanisms of the inactivation and reactivation of CMV promoter-controlled transgenes should help develop an effective strategy to fully activate the CMV promoter-controlled therapeutic genes silenced by the host cells.

Animals↗
PubMed2006

Sodium butyrate induces apoptosis and cell cycle arrest in primary effusion lymphoma cells independently of oxidative stress and p21(CIP1/WAF1) induction.

Primary effusion lymphoma, a peculiar type of B cell non-Hodgkin lymphoma, preferentially develops in immunodeficient individuals and its pathogenesis is closely linked with human herpesvirus 8 (HHV-8). HHV-8 is present primarily persistence in primary effusion lymphoma cells, and the lytic cycle of HHV-8 can be induced by sodium butyrate (NaB) treatment. HHV-8 gene expression is affected by NaB in BCBL-1 cells, but the cellular response of BCBL-1 cells upon NaB treatment has not been investigated to date. Using BCBL-1 cells, a HHV-8 harboring cell line, we demonstrated that sodium butyrate could induce the reactive oxygen species generation, apoptosis and cell cycle arrest in BCBL-1 cells. The sodium butyrate-induce cell cycle arrest was associated with the decrease of Cdc2, Cdk4 and cyclin A in BCBL-1 cells without altering the protein levels of p21(CIP1/WAF1). The apoptosis induced by sodium butyrate in BCBL-1 cells was independent of oxidative stress.

Apoptosis↗
PubMed1980

Sodium n-butyrate induces prostaglandin synthetase activity in mastocytoma P-815 cells.

Cultured mouse mastocytoma P-815 cells were treated with 1 mM sodium n-butyrate for 40 h. The treated cell homogenate showed high activities in synthesizing prostaglandin D2, E2, and F2 alpha. Such activities were virtually absent in untreated cell homogenate. Direct addition of sodium n-butyrate to the homogenate showed no effects. Pre-exposure of cells to acetylsalicylic acid did not diminish the effect of the subsequent treatment with sodium n-butyrate. These data suggest that sodium n-butyrate induces fatty acid cyclooxygenase in P-815 cells.

Animals↗
PubMed1995

Effect of germfree state on the capacities of isolated rat colonocytes to metabolize n-butyrate, glucose, and glutamine.

BACKGROUND & AIMS: Among substrates available to the colonic mucosa, n-butyrate from bacterial origin represents a major fuel. The present work investigated possible modifications of energy substrate metabolism in colonocytes isolated from germfree rats. METHODS: Colonocytes isolated from germfree vs. conventional rats were incubated (30 minutes at 37 degrees C) in the presence of 14C-labeled n-butyrate (10 mmol/L), glucose (5 mmol/L), or glutamine (5 mmol/L). 14CO2 and metabolites generated were measured. Possible regulatory steps were also investigated. RESULTS: Glucose use rate was 25% lower in germfree rat colonocytes due to a reduced glycolytic capacity in these cells. Differences in 6-phosphofructo-1-kinase activity could account for this decrease. In contrast, glutamine use rate was 45% higher, and this was correlated with a higher maximum velocity of glutaminase in these cells. Nevertheless, the capacities to oxidize glucose and glutamine remained unchanged. Although the capacity to use n-butyrate was maintained in colonocytes of germfree rats, the ketogenic capacity was lower, whereas the capacity to oxidize n-butyrate was higher. The mitochondrial 3-hydroxy-3-methylglutaryl-coenzyme A synthase protein was identified in the colonic mucosa. Moreover, the messenger RNA and amount of protein were 75% lower in the germfree state. CONCLUSIONS: The absence of an intestinal microflora induces specific changes in the metabolic capacities of colonocytes.

Animals↗
PubMed1988

Mechanism of L-triiodothyronine (T3) uptake by glial C6 cells: regulation by butyrate.

The mode of entry of triiodothyronine (T3) and its regulation by butyrate was studied in cultured glial C6 cells. Uptake of [125I]T3 increases for at least 60 min in C6 cells. The amount of cell-associated radioactivity is 2- to 4-fold higher during the entire time-course in cells previously exposed to 2 mM butyrate for 48 h. Uptake was non-saturable since uptake velocity was linearly related to the extracellular hormone concentration between 0.2 and 800 nM T3 in control and butyrate-treated cells. Uptake velocity increased by more than 3-fold in the cells incubated with the fatty acid. T3 uptake was temperature dependent and the effect of butyrate was observed at the different temperatures examined. Preincubation with metabolic inhibitors did not block [125I]T3 uptake in either group, and monodansylcadaverine was also ineffective. Present results suggest that in C6 cells T3 uptake proceeds by a passive, energy-independent, non-saturable process, that is markedly affected by short-chain fatty acids. Additionally, this is the first study documenting that a natural compound directly influences the entry of thyroid hormones into cells.

Animals↗
PubMed1994

Butyrate as a differentiating agent: pharmacokinetics, analogues and current status.

The field of butyrate-induced differentiation of neoplastic and non-neoplastic cells is reviewed and possible clinical correlations considered with regard to butyrate, butyrate prodrugs and butyrate analogues. These topics are discussed from the point of view of the concentrations required in vitro for biologic effect, and likely pharmacokinetic behavior in vivo.

Anemia, Sickle Cell↗
PubMed2004

Butyrate regulation of glycosylation-related gene expression: evidence for galectin-1 upregulation in human intestinal epithelial goblet cells.

Glycosylation of mucins produced by human intestinal goblet cells plays a crucial role in their functions: mucus gel physico-chemical protective properties, host-bacteria interactions, cell-cell adhesion, cell migration, and cell signaling. Colonic mucin glycosylation can be modified by luminal metabolites of fiber fermentation like butyrate. Our aim was to assess the effect of butyrate on the expression of a large panel of glycosylation-related genes in human intestinal epithelial goblet cells HT29-Cl.16E. We found that only a very scarce group of genes: 9 out of 252 were evidenced by microarray screening, and only three had their modulation significantly confirmed by real time PCR quantification. The most striking effect of butyrate was its 8- to 18-fold increase of galectin-1 gene expression, which was confirmed at the protein level, specifically with a central and apical intracellular localization. Significant butyrate effects will be discussed in regard to their possible link with mucins expressed by HT29-Cl.16E cells.

Butyrates↗
PubMed2006

n-Butyrate inhibits Jun NH(2)-terminal kinase activation and cytokine transcription in mast cells.

Mast cells are well known to contribute to type I allergic conditions but only recently have been brought in association with chronic relapsing/remitting autoimmune diseases such as celiac disease and ulcerative colitis. Since the bacterial metabolite n-butyrate is considered to counteract intestinal inflammation we investigated the effects of this short chain fatty acid on mast cell activation. Using RNAse protection assays and reporter gene technology we show that n-butyrate downregulates TNF-alpha transcription. This correlates with an impaired activation of the Jun NH(2)-terminal kinase (JNK) but not other MAP kinases such as ERK and p38 that are largely unaffected by n-butyrate. As a consequence, we observed a decreased nuclear activity of AP-1 and NF-AT transcription factors. These results indicate that n-butyrate inhibits critical inflammatory mediators in mast cells by relatively selectively targeting the JNK signalling.

Animals↗
PubMed2005

Peroxisome proliferator-activated receptor alpha expression is regulated by estrogen receptor alpha and modulates the response of MCF-7 cells to sodium butyrate.

Peroxisome proliferator-activated receptors are ligand-activated transcription factors with a potential role in cancer. We investigated peroxisome proliferator-activated receptor alpha expression in breast cancer cell lines and showed a relationship between mean peroxisome proliferator-activated receptor alpha and estrogen receptor alpha mRNA levels in estrogen receptor alpha positive breast cancer cells. Transfection of estrogen receptor alpha into the estrogen receptor alpha negative cell line, MDA-MB-231 decreased peroxisome proliferator-activated receptor alpha mRNA and conversely inhibition of estrogen receptor alpha by ICI-182 780 in estrogen receptor alpha positive, MCF-7 cells increased peroxisome proliferator-activated receptor alpha mRNA levels. Estrogen receptor alpha levels can be modulated by histone deacetylase inhibitors and such agents are in clinical trials for cancer treatment. We found the histone deacetylase inhibitor, sodium butyrate, increased peroxisome proliferator-activated receptor alpha mRNA levels within 4h of treatment. Peroxisome proliferator-activated receptor alpha modulation was independent of estrogen receptor alpha, as a similar increase was observed in the estrogen receptor alpha negative MDA-MB-231 cells. To further investigate the relationship between sodium butyrate and peroxisome proliferator-activated receptor alpha expression, we created an MCF-7 cell line that conditionally over-expresses human peroxisome proliferator-activated receptor alpha. Over-expression of the peroxisome proliferator-activated receptor protected MCF-7 cells from sodium butyrate-mediated inhibition of proliferation and attenuated sodium butyrate-mediated induction of histone deacetylase 3 mRNA, indicating that elevated levels of peroxisome proliferator-activated receptor alpha may reduce the sensitivity of cells to histone deacetylase inhibitors. The estrogen receptor alpha dependence of peroxisome proliferator-activated receptor alpha levels may be significant since estrogen receptor alpha negative breast cancer cells are associated with a more aggressive phenotype. Our studies also suggest that peroxisome proliferator-activated receptor alpha levels may be a marker of breast cancer cell sensitivity to histone deacetylase inhibitors.

Butyrates↗
PubMed2005

Sensitization of colon cancer cell lines to butyrate-mediated proliferation inhibition by combined application of indomethacin and nordihydroguaiaretic acid.

The aim of the study was to investigate the effects of nonsteroidal anti-inflammatory drugs (NSAIDs) on histone deacetylase-mediated proliferation inhibition. In the colon cancer cell line HT29 butyrate-mediated proliferation inhibition was enhanced by the additional presence of indomethacin (IM) and/or nordihydroguaiaretic acid (NDGA). Sensitisation to butyrate-mediated proliferation inhibition was abolished by the general caspase inhibitor Z-VAD-fmk, however, only IM-induced cell detachment was prevented by the caspase inhibitor but not that induced by NDGA or NDGA plus IM. In contrast to the parental cell line HT29, in the methotrexate-resistant sub-lines HT29-12 and HT29-21, IM counteracted butyrate-mediated proliferation inhibition, which was abrogated by NDGA. In all the investigated cell lines, proliferation inhibition was most effectively achieved under the combined application of butyrate with IM and NDGA, suggesting that inhibition of both cyclooxygenase (COX) and lipoxygenase (LOX) isoenzymes is needed for proliferation inhibition by NSAIDs in tumour cells.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2006

Contribution of C. beijerinckii and C. sporogenes in association with C. tyrobutyricum to the butyric fermentation in Emmental type cheese.

The relationship between C. tyrobutyricum, C. sporogenes and C. beijerinckii in experimental cheese conditions, and their influences on late-blowing and butyric fermentation, have been investigated. A molecular approach using a PCR-TTGE method in combination with conventional methods, such as microbiological and physico-chemical analysis, was performed to monitor the evolution of these clostridial species, simultaneously with the occurrence of cheese defects. Sixteen Emmental type cheeses were produced from milk inoculated with different clostridial spore associations. In all cheeses inoculated with C. tyrobutyricum, obvious signs of late blowing were detected. In cheeses inoculated with C. beijerinckii or C. sporogenes, a formation of holes in cheese body was observed, with a concomitant slight amount of butyric acid production. Even though C. beijerinckii and C. sporogenes were less metabolically active and less numerically important than C. tyrobutyricum in cheese as shown by TTGE profiles, the association of these species to C. tyrobutyricum enhanced the butyric fermentation and the cheese defects. The level of butyric content in ripened cheese increased to 268 mg 100 g(-1) in presence of C. tyrobutyricum, and reached a maximum of 414 mg 100 g(-1) in presence of the C. beijerinckii-C. tyrobutyricum (1:10) association. The propionic fermentation was also higher in cheese inoculated with C. tyrobutyricum, and was slowed down in presence of C. beijerinckii and C. sporogenes. From 30 days of ripening, a strong correlation between the chemical contents and the intensity of cheese defects was demonstrated. A chemical analysis of cheese associated with a molecular method for microbial spoilage investigation allows the prediction of the level of late blowing at early stages of ripening, and the understanding of the origin of the defect.

Butyric Acid↗
PubMed2004

Sodium butyrate suppresses interferon-gamma-, but not lipopolysaccharide-mediated induction of nitric oxide and tumor necrosis factor-alpha in microglia.

In the present study, we demonstrate that sodium butyrate repressed IFN-gamma-induced expression of iNOS and TNF-alpha, but had little effect on LPS-induced expression in BV2 murine microglial cells. Sodium butyrate significantly inhibited NF-kappa B binding and NF-kappa B-mediated transcription induced by IFN-gamma, suggesting that the anti-inflammatory effect of sodium butyrate is mediated via specific inhibition of the NF-kappa B pathway. IFN-gamma is a major stimulator of innate and adaptive immune response. Thus, the specific down-regulation of IFN-gamma-induced microglial activation by sodium butyrate may provide potential therapeutic strategies for a variety of inflammatory diseases in the central nervous system.

Animals↗
PubMed2002

The effect of retinoids and butyrate on the expression of CRX and IRBP in retinoblastoma cells.

We sought to determine whether differentiation agents such as retinoids and butyrate regulate transcript levels of interphotoreceptor retinoid binding protein (IRBP) and cone rod homeobox (CRX), a homeodomain transcription factor that regulates IRBP promoter activity. WERI-Rb1 retinoblastoma cells were treated with all-trans retinol, all-trans retinoic acid, or butyrate. IRBP and CRX mRNA levels were determined by quantitative RT-PCR. Butyrate at low concentrations increased both mRNA levels but suppressed them at higher concentrations. Retinoic acid had minimal effects. Retinol increased CRX mRNA over four fold. IRBP and CRX transcript levels are sensitive to butyrate and CRX expression is sensitive to retinol.

Butyrates↗
PubMed2002

Effects of C18 long chain fatty acids on glucose, butyrate and hydrogen degradation.

The effects of linoleic (C18:2), oleic (C18:1), and stearic (C18:0) acids on glucose, butyrate and hydrogen degradation were investigated at 21 degrees C using a culture unacclimated to long-chain fatty acids (LCFAs). Diethyl ether was used to facilitate precise addition of LCFAs and provide adequate dispersion in cultures. Butyrate degradation was affected by diethyl ether but minimal effects were observed on hydrogen and glucose consumption. In the presence of oleic and stearic acids, the glucose consumption rate was similar but was approximately 50% lower in the presence of linoleic acid. The effect of a mixture of 100 mg l(-1) of each individual LCFA (300 mg l(-1) total LCFA) was approximately the same as 100 mg l(-1) linoleic acid alone, suggesting no synergistic inhibition of glucose degradation. Butyric acid degradation was more severely inhibited by the LCFAs with inhibition becoming more severe with the addition of double bonds to the LCFA. Furthermore, mixtures of LCFAs synergistically inhibited butyric acid degradation compared to the results with individual LCFAs. In contrast, although lower hydrogen consumption rates were observed in cultures receiving oleic and linoleic acids compared to cultures receiving stearic acid, inhibition by all three acids individually or in mixture was limited. The introduction of LCFAs into a system may severly inhibit intermediate acid degradation while having little effect on acid production.

Bioreactors↗
PubMed2002

Arginine butyrate increases the cytotoxicity of DAB(389)IL-2 in leukemia and lymphoma cells by upregulation of IL-2Rbeta gene.

DAB(389)IL-2 (ONTAK) is a fusion protein consisting of the ADP-ribosyltransferase and membrane translocating domains of native diphtheria toxin and the full-length sequence for interleukin-2 (IL-2) gene. In vitro data demonstrates that DAB(389)IL-2 is cytotoxic to cells expressing the high affinity IL-2 receptor (IL-2R). In Phases I and II clinical trials of patients whose tumor cells express a component of the IL-2R, the response rates were 18% for B-cell non-Hodgkin lymphoma (NHL) and 30% for cutaneous T-cell lymphoma (CTCL). In this study, we examined the effects of arginine butyrate on IL-2R expression and susceptibility of leukemia cells to intoxication by DAB(389)IL-2. We demonstrate that the p75 subunit of the IL-2R (IL-2Rbeta) is upregulated in the presence of low concentrations of arginine butyrate (0.06mM) which had no direct growth inhibitory effect on the cells. To explore mechanisms of this upregulation, we examined the effect of 0.06mM arginine butyrate on relevant transcriptional elements and on histone deacetylase and found activation of cAMP response element (CRE) but not NFAT or NFKB, as well as inhibition of histone deacetylase (HDAC). Our results suggest that the effects of physiologically achievable concentrations of butyrate on IL-2R expression could be exploited to enhance the susceptibility of intermediate and low-affinity IL-2R expressing leukemia cells to DAB(389)IL-2.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

Butyric acid mediated induction of enhanced transendothelial resistance in an in vitro model blood-brain barrier system.

Previously we reported that the co-culture of non-brain vascular endothelial cells with glioma cells leads to the induction of a more differentiated endothelial cell phenotype which exhibits important properties of the blood-brain barrier (BBB). Recognising the potential for improving the model barrier system with agents known to modify the growth and differentiation of cells in culture we examined the effects of four differentiating agents (butyric acid, dexamethasone, retinoic acid, and dimethyl sulfoxide) on barrier function. Of these agents only butyric acid and dexamethasone resulted in an enhancement (depending on the dose used) of transendothelial electrical resistance (barrier function). The greatest effect was observed with butyric acid in a dose-dependent manner and was slow in onset and only occurred in the endothelial/glial cell co-cultures. These data indicate that butyric acid may be a beneficial agent in optimising conditions necessary for induction of BBB properties in in vitro barrier systems.

Blood-Brain Barrier↗