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Effects of n-butyrate on Epstein-Barr virus-carrying lymphoma lines.

n-Butyrate has been shown to induce Epstein-Barr virus (EBV) antigen synthesis in certain EBV-carrying lymphoma lines (Luka et al., 1979). We have studied the effect of n-butyrate on two EBV-positive Burkitt lymphoma lines by immuno-fluorescence and electron microscopy. In the producer line P3HR-1, the drug induced not only early antigen (EA) and virus capsid antigen (VCA) synthesis, as shown before, but also increased the number of cells containing virus particles. The transition from VCA expression to the formation of virus particles was much more effective in treated cells than in EBV antigen-producing cells of the same line. The productive cycle was associated with the development of characteristic morphological changes. In the non-producer Raji cells, n-butyrate induced EA in only a minor fraction of the cells. There were, however, clear signs of differentiation in the direction of plasma cells. Two days after the addition of n-butyrate 80% of the Raji cells could be classified as plasmablasts. After 72 h, 20% of the cells appeared as typical plasma cells.

Antigens, Viral↗

Increase in the level of P-glycoprotein mRNA expression in multidrug-resistant K562 cell lines treated with sodium butyrate is not accompanied with erythroid differentiation.

We examined the effect of hemin, sodium butyrate and mitomycin C on levels of P-glycoprotein mRNA in human myelogenous K562 cells by northern blot analysis. After treatment with sodium butyrate a dose-dependent increase of P-glycoprotein mRNA expression was observed in the adriamycin-resistant K562 and vincristine-resistant K562 lines. With 10 mM sodium butyrate, the level of P-glycoprotein mRNA reached 20 times that of control adriamycin-resistant K562 and with 30 mM sodium butyrate, it exceeded 5 times that of control vincristine-resistant K562. In contrast, hemin and mitomycin C had almost no effect on P-glycoprotein mRNA. In this experiment, since expression of P-glycoprotein mRNA was not necessarily accompanied with induction of erythroid differentiation, the increased amount of P-glycoprotein mRNA is unlikely to be a result of differentiation.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

In vitro and in vivo induction of squamous cell carcinoma antigen (SCC) in a uterine cervical cancer cell line (SKG-IIIa) with peplomycin and sodium butyrate.

In order to investigate the effect of an antisquamous cell carcinoma drug, peplomycin, the new analogue of bleomycin, on the production of a squamous cell carcinoma-associated tumor marker termed "SCC" (or TA-4), we carried out in vitro and in vivo experiments using the uterine cervical epidermoid cancer cell line SKG-IIIa, together with the investigation of the effect of sodium butyrate which was reported to be one of the representative gene modulators. In vitro production of SCC was biochemically and immunocytochemically confirmed in SKG-IIIa cells. Immunocytochemistry using anti-SCC antibody revealed that the total number of SCC-positive cells increased after the treatment with peplomycin (1.6 fold) or sodium butyrate (1.5 fold). The total amount of SCC in cultured medium, intracellular SCC, and cell debris during 5 days of culturation also increased with peplomycin (1.8 fold) and sodium butyrate (1.4 fold). These data strongly suggest that SCC production of SKG-IIIa cells is stimulated by peplomycin and sodium butyrate in vitro. In vivo experiments were also performed by administering peplomycin to nude rats with heterotransplanted tumors of SKG-IIIa, and transient elevations of serum SCC level (113% to 238% of the initial values) were observed, suggesting that SCC production of cancer cells is also stimulated by peplomycin in vivo.

Animals↗

Pancreatic neuroendocrine responses to butyrate in conscious sheep.

The role of the autonomic innervation in the control of pancreatic endocrine responses to I.V. infusions of butyrate (0.02 mmol kg-1 min-1 for 10 min) has been investigated in conscious 4-6 month old weaned lambs. Intravenous butyrate produced a small rise in mean arterial plasma pancreatic glucagon concentration which was unlikely to have had any physiological effect and produced no consistent or statistically significant changes in mean plasma pancreatic polypeptide concentration in any of the groups studied. In contrast, butyrate produced an abrupt and substantial rise in mean plasma insulin concentration, which rose to a peak incremental value of about 300 pmol l-1 in normal control lambs. This response was unaffected by pre-treatment with either phentolamine or propranolol alone, but was significantly reduced by simultaneous administration of these drugs, as it was either by pre-treatment with atropine or prior section of the splanchnic nerves. The rise in mean plasma insulin concentration was inhibited most effectively by combined treatment with propranolol, phentolamine and atropine, which was significantly more effective than administration of atropine to lambs with cut splanchnic nerves (P less than 0.01). It is concluded that both divisions of the autonomic nervous system are likely to be involved in mediating the release of insulin from the pancreas, in response to butyrate, in this species under these experimental conditions and also in the resting state.

Animals↗

Transcriptional regulation of genes encoding insulin, glucagon, and angiotensinogen by sodium butyrate in a rat islet cell line.

The state of differentiation of various neoplastic cell lines is inversely correlated with the rate of cellular growth. To delineate the changes in hormone gene expression associated with an induced decrease in the growth rate of rat insulinoma cells, we studied the effects of sodium butyrate on the expression of the genes encoding insulin, glucagon, and angiotensinogen. Sodium butyrate inhibited cellular proliferation and decreased levels of c-myc mRNA. Concomitantly, steady-state levels of mRNAs encoding insulin and glucagon increased by 10- and 8.5-fold, respectively, as a result of a specific increase in the transcription of both genes. Sodium butyrate also inhibited angiotensinogen gene expression, which was ectopic in the insulinoma cells. These observations suggest that sodium butyrate induces a pattern of events leading to the differentiation of the rat insulinoma cells.

Angiotensinogen↗

Increasing butyrate concentration in the distal colon by accelerating intestinal transit.

BACKGROUND: Populations at low risk of colonic cancer consume large amounts of fibre and starch and pass acid, bulky stools. One short chain fatty acid (SCFA), butyrate, is the colon's main energy source and inhibits malignant transformation in vitro. AIM: To test the hypothesis that altering colonic transit rate alters colonic pH and the SCFA content of the stools. PATIENTS: Thirteen healthy adults recruited by advertisement. METHODS: Volunteers consumed, in turn, wheat bran, senna and loperamide, each for nine days with a two week washout period between study periods, dietary intake being unchanged. Before, and in the last four days of each intervention, whole gut transit time (WGTT), defaecation frequency, stool form, stool beta-glucuronidase activity, stool pH, stool SCFA concentrations and intracolonic pH (using a radiotelemetry capsule for continuous monitoring) were assessed. RESULTS: WGTT decreased, stool, output and frequency increased with wheat bran and senna, vice versa with loperamide. The pH was similar in the distal colon and stool. Distal colonic pH fell with wheat bran and senna and tended to increase with loperamide. Faecal SCFA concentrations, including butyrate, increased with senna and fell with loperamide. With wheat bran the changes were non-significant, possibly because of the short duration of the study. Baseline WGTT correlated with faecal SCFA concentration (r = -0.511, p = 0.001), with faecal butyrate (r = -0.577, p < 0.001) and with distal colonic pH (r = 0.359, p = 0.029). CONCLUSION: Bowel transit rate is a determinant of stool SCFA concentration including butyrate and distal colonic pH. This may explain the inter-relations between colonic cancer, dietary fibre intake, stool output, and stool pH.

Adult↗

Regulation of surfactant protein A mRNA by hormones and butyrate in cultured fetal rat lung.

We have previously shown that dexamethasone, triiodothyronine (T3) and dibutyryl adenosine 3',5'-cyclic monophosphate (cAMP) stimulate phosphatidylcholine (PC) synthesis in fetal rat lung explants in culture. There are also additive interactions between these agents with regard to PC synthesis. In this study we examined the regulation of surfactant protein A (SP-A) mRNA in fetal rat lung in culture. Dexamethasone increased SP-A mRNA in the explants in a dose-dependent fashion (1-200 nM), but T3 did not. Whereas 8-bromo-cAMP increased SP-A mRNA, a decrease was observed with dibutyryl cAMP. These findings support the view that at least some of the genes involved in the synthesis of the various components of surfactant are independently regulated. Since we observed differences in the effects of a cAMP analogue which contained butyrate and one that did not, explants were then cultured with Na butyrate, a known regulator of gene expression. A significant decrease in SP-A mRNA was observed at mM concentrations. Exposure of the explants to alpha-aminobutyric acid, a butyric acid analogue which is elevated in the blood of infants of diabetic mothers, resulted in a significant decrease in SP-A mRNA at a concentration 1/25 of that required for Na butyrate. This observation raises the question of whether the decreased SP-A levels reported in fetuses of diabetic mothers may, at least in part, be related to this metabolite.

8-Bromo Cyclic Adenosine Monophosphate↗

Sodium butyrate inhibits the enhancing effect of high fat diet on mammary tumorigenesis.

We have studied the effect of butyrate on mammary tumorigenesis by 7,12-dimethylbenz(a)anthracene. As reported previously, a high incidence of mammary tumors was observed in rats fed a basal diet containing 20% margarine. However, the enhancing effect of margarine was inhibited when sodium butyrate was supplemented in the high margarine diet. Sodium butyrate did not cause any effect when it was supplemented in the basal diet. The result suggests a possibility that a part of the inhibitory effect of butter on mammary tumorigenesis, which we had previously reported, was caused by butyrate milk lipids.

9,10-Dimethyl-1,2-benzanthracene↗

Na-K-2Cl cotransporter gene expression and function during enterocyte differentiation. Modulation of Cl- secretory capacity by butyrate.

The basolateral Na-K-2Cl cotransporter (NKCC1) is a key component of the intestinal crypt cell secretory apparatus. Its fate during the transition to absorptive enterocyte and the potential impact of its altered expression on secretory output have not been addressed. In this report, NKCC1 mRNA was found to be expressed in rat jejunal crypt but not villus cells. Butyrate treatment of intestinal epithelial HT29 cells induced a differentiation pattern that recapitulated the rat intestinal crypt-villus axis, with NKCC1 mRNA levels decreasing in a time- and dose-dependent fashion in parallel with upregulation of apical brush-border markers. Butyrate but not acetate or proprionate decreased basal and cAMP-stimulated bumetanide-sensitive K+ (86Rb) uptake in both HT29 cells and the Cl--secreting T84 line. Butyrate markedly decreased transepithelial Cl- secretion in confluent T84 monolayers without effect on cAMP-regulated apical Cl- efflux. We conclude that NKCC1 regulation during enterocyte differentiation occurs at the level of gene expression, and that selective downregulation of NKCC1 gene expression and function by butyrate leads to a profound decrease in transepithelial Cl- secretion. These data emphasize the importance of NKCC1 in determining epithelial secretory capacity and suggest the possibility of modulation of the enterocytic transport phenotype as therapy for diarrheal disorders.

Animals↗

n-Butyrate inhibition of hyaluronate synthesis in cultured human fibroblasts.

The effects of the short-chain aliphatic carboxylic acid, n-butyrate, on glycosaminoglycan (GAG) accumulation were studied in cultured human skin fibroblasts. Normal fibroblast cultures were grown to confluence, shifted to a medium without or with n-butyrate for 24 h, labeled with either [3H]acetate or [3H]glucosamine and analyzed for [3H]GAG and [3H]hyaluronate accumulation. Accumulation was stimulated at low concentrations (0.1-1 mM) by up to 27%. Higher concentrations of n-butyrate (greater than 1 mM) inhibited [3H]GAG by up to 70-90%. This effect was maximal at 10 mM and half-maximal at 3 mM. Propionate had similar effects but was less potent. Parallel studies conducted in colonic fibroblasts revealed that n-butyrate could markedly inhibit [3H]GAG accumulation in that cell type as well. These effects were rapid, occurring within 3 h of treatment, and were reversible. Chondroitin sulfate accumulation was unaffected by the compound. A pulse-chase study failed to demonstrate any effect on [3H]GAG degradation.

Acetates↗

Proenkephalin gene expression in the PC12 pheochromocytoma cell line: stimulation by sodium butyrate.

The differentiation promoter sodium butyrate increases the content of Met5-enkephalin-Arg6-Gly7-Leu8 (Met5-enk-RGL)-immunoreactive peptides in PC12 pheochromocytoma cells, which, unlike mature adrenomedullary chromaffin cells, contain exceedingly low levels of opioid peptides. These butyrate-induced enkephalin-immunoreactive peptides, which are specific products of the proenkephalin gene, consist principally of two high mol wt forms of amino-terminally extended Met5-enk-RGL. These high mol wt peptides, with apparent mol wt of 20,000 and 10,000, are approximately the same size as the two major immunoreactive peptides found in adult New England Deaconess Hospital rat adrenal. The low mol wt Met5-enk-RGL-immunoreactive peptide found in butyrate-treated cells is similar in size to authentic Met5-enk-RGL, which is not found in the adrenal medulla of the adult rat. When PC12 cells are grown as a tumor in vivo, the amount of Met5-enk-RGL-immunoreactive peptide increased only slightly above the level found in control cells grown in vitro and consisted exclusively of the highest mol wt immunoreactive species. In PC12 cells, the butyrate-stimulated elevation in the content of Met5-enk-RGL-immunoreactive peptides may involve changes in transcription, since the peptide increase is preceded by a 2- to 3-fold increase in the level of proenkephalin mRNA. These results suggest that the PC12 cell line may be useful for investigating those factors that control the initial expression and processing of proenkephalin-derived peptides during embryogenesis.

Adrenal Gland Neoplasms↗

Sodium butyrate increases glucagon and insulin gene expression by recruiting immunocytochemically negative cells to produce hormone.

Current evidence suggests that a multipotential endodermal progenitor cell may give rise to all islet cell phenotypes. We characterized two hormone-producing rat islet (RIN) cell lines derived from a radiation-induced islet tumor by immunocytochemistry, Northern blot analysis, and radioimmunoassay of secreted hormone. Using antisera to glucagon, insulin, and somatostatin, we found that less than 15% of the cells in any of these three islet cell lines contained immunopositive cells. The number of cells staining for the hormone correlated with mRNA levels and immunoreactive secreted hormones. Sodium butyrate, a short-chain aliphatic fatty acid, slowed cell growth and increased dramatically the percentage of cells staining for glucagon and insulin. The increase in immunopositive cells was accompanied by an increase in glucagon and insulin mRNAs and secreted glucagon and insulin. These observations indicate that sodium butyrate increases glucagon and insulin gene expression by recruiting previously immunonegative cells to produce hormone. The relationship of DNA synthesis and hormone production was assessed by pulse-labeling RIN cells with [3H]thymidine, which was followed by autoradiography and immunocytochemistry. [3H]thymidine incorporation was observed in a lower percentage of immunopositive compared with immunonegative cells. Furthermore, sodium butyrate reduced the number of [3H]thymidine-labeled cells and increased the number of immunopositive cells. These observations suggest that sodium butyrate differentiates the islet cells and thereby increases the expression of the glucagon and insulin genes.

Adenoma, Islet Cell↗

Effects of propionate and methylmalonate on conversions of acetate, butyrate, and D(-)-3-hydroxybutyrate to fatty acids and carbon dioxide by mammary tissue slices of goats.

Incorporations of [1-carbon-14] acetate, [1-carbon-14] propionate, n-[1-carbon-14] butyrate, and D(-)-3-hydroxy[3-carbon-14] butyrate into individual milk fatty acids and their conversion to carbon dioxide were studied in vitro with caprine mammary tissue slices in the presence and absence of propionate and methylmalonate. Neither propionate nor methylmalonate affected incorporation of these substances into fatty acids. In a decreasing order butyrate, acetate, propionate, and D(-)-3-hydroxybutyrate were converted to carbon dioxide. Acetate had the highest incorporation rate into fatty acids followed by D(-)-3-hydroxybutyrate, butyrate, and propionate. Labeled propionate was incorporated mainly into odd-numbered fatty acids. Results do not support the theory that either propionate or its metabolite, methylmalonate, inhibit de novo synthesis of fatty acids in the mammary gland in relation to the etiology of low milk fat syndrome.

3-Hydroxybutyric Acid↗

[Suppressive effect of CDDP on induction of the Epstein-Barr virus antigen synthesis by n-butyrate].

n-Butyrate has been shown to induce Epstein-Barr virus (EBV) antigen synthesis in certain EBV genome-carrying lymphoblastoid cell lines. We have studied the effect of cis-dichloro-diamine-platinum (CDDP) on induction of EBV antigen synthesis not only by n-butyrate treatment of the EBV producer, P3HR-1 cells, but also by superinfection of EBV to the EBV non-producer, Raji cells. Simultaneous treatment of the cells with n-butyrate and CDDP or MMC blocked VCA and EA induction, but no suppressive effect was observed by the treatment of the cells with n-butyrate and Ara-C. The induction of EBV antigens was also observed in EBV-superinfected Raji cells, even in the presence of DNA synthesis inhibitor, CDDP or MMC. From these results, we discussed the mechanisms of the EBV antigens synthesis in EBV latently infected cells.

Antigens, Viral↗

The long-term effects of 5-fluorouracil and sodium butyrate on human Tenon's fibroblasts.

The use of subconjunctival 5-fluorouracil (5-FU) in the first weeks after filtration surgery may ensure long-term bleb survival despite a continuing proliferative stimulus such as in eyes with neovascular glaucoma. In addition, long-term side effects may occur, such as increasing bleb thinning. To ascertain the long-term effects of 5-FU and sodium butyrate, an agent with differentiating and antiproliferative properties, we exposed proliferating human Tenon's capsule fibroblasts to different concentrations of the drugs. The cells were exposed to 5-FU for 1-12 d. The cells were subsequently observed for up to 30 d. Cell proliferation was assessed using cell counting and bromodeoxyuridine uptake, and cell viability was assessed with trypan blue uptake. 5-FU and sodium butyrate inhibited fibroblast proliferation during the treatment period. Higher concentrations of 5-FU (100 and 1000 micrograms/ml) for as little as 1 d resulted in no significant increase in the number of fibroblasts for at least 29 d after treatment was stopped, despite continued stimulation with serum. When treatment with sodium butyrate was stopped, there was greater recovery of proliferation. At a constant concentration of 1000 micrograms/ml of 5-FU for 3 or more days, or a concentration of 100 mmol/l sodium butyrate for 12 d, the entire fibroblast population gradually died over the 30 d period. Thus, short-term treatment with 5-FU may result in long-term inhibition of proliferation of fibroblasts. Long-term inhibition depends on the duration of treatment or on the concentration of 5-FU. Short-term treatment may be affecting the ability of the tissues at the bleb site to heal in the long term. Different dosage regimens may have advantages and are discussed.

Adolescent↗

Transcriptional regulation of the human placental-like alkaline phosphatase gene and mechanisms involved in its induction by sodium butyrate.

The human alkaline phosphatases constitute a multigene family with at least four members. Placental-like alkaline phosphatase (PLAP) is of particular interest because it is frequently present in tumors, where it serves as a marker of malignant transformation. Moreover, its expression is highly inducible by differentiating agents such as sodium butyrate. In the present study we have examined the PLAP gene promoter in order to better understand the mechanisms involved in its expression and induction. The PLAP promoters from four colon cancer cell lines with widely varied butyrate-inducible alkaline phosphatase activity were thermally amplified and sequenced. The overall sequence similarity of this region was found to be 99% between cell lines; thus, sequence variation of the promoter does not appear to account for the differential expression of this marker. We therefore analyzed the activity of the LS174T cell PLAP promoter using transient transfection experiments. Here, the 5'-flanking region of the gene was found to have positive regulatory elements in nucleotides -1 to -170 and -363 to -512 (relative to the start of transcription). A negative control element was also found to be present in the region between nucleotides -170 and -363. Mobility shift electrophoresis indicated that a nuclear factor bound to the promoter between bases -182 and -341. Furthermore, the activity of the PLAP promoter was found to be inducible by sodium butyrate. In contrast, the closely related placental alkaline phosphatase gene promoter exhibited almost no response to this agent. These results confirm that the activity of the PLAP promoter is stimulated by sodium butyrate and delineate regions that control this induction process.

Alkaline Phosphatase↗

Feeding trial in pigs with a diet containing sodium n-butyrate.

Pigs weighing 7 to 102 kg were fed a diet containing 0.17% sodium n-butyrate. The diet increased the average daily body mass gain of pigs by 23.5%. Due to its dietetic effect, feed consumption increased by 8.9%. However, owing to the higher feed conversion, specific feed utilization was reduced by 11.8%. The experimental diet markedly reduced the percentile proportion of coliform bacteria in the ileum as compared to Lactobacillus ssp.: it decreased the coliform count and increased the counts of Lactobacillus spp. The diet increased the length of ileal microvilli and the depth of caecal crypts. It raised the concentration of immunoreactive insulin in the blood plasma. The feed supplemented with sodium butyrate did not alter adversely the clinical indices tested. It reduced feed costs by 9% and increased the returns from sales by 13%. As the additive is normally produced by microbial fermentation in the large intestine, it is not alien to the body. Sodium butyrate exerted its favourable effect in 3.6- to 24.2-fold lower concentrations than the organic acids (citric acid, fumaric acid, propionic acid) used earlier. With respect to its favourable biological and economic effect, sodium n-butyrate can be recommended for use in pig feeding as a growth promoter.

Animal Feed↗

Sodium butyrate and a T lymphocyte cell line-derived differentiation factor induce basophilic differentiation of the human promyelocytic leukemia cell line HL-60.

Sodium butyrate induces basophilic differentiation of HL-60 promyelocytic leukemia cells that have been previously passaged in alkaline medium. A factor present in Mo conditioned medium (Mo-CM) acts synergistically with sodium butyrate to promote basophilic maturation in a dose-dependent fashion. The induced HL-60 cells exhibit nuclei at various stages of maturity and cytoplasmic granules staining azurophilic with May-Grünwald-Giemsa and metachromatically with toluidine blue. The histamine content of induced HL-60 cells is 50 ng/10(6) cells with sodium butyrate alone or 190 ng/10(6) cells with butyrate in combination with Mo-CM. Induced cells release histamine in response to anti-IgE and have receptors for the Fc portion of human IgE. The basophilic cell-differentiating activity present in Mo-CM appears to be distinct from several other cytokines including recombinant human interleukin-1 alpha, interleukin-2, interferon-gamma, interferon-alpha, murine interleukin-3, erythroid-potentiating activity, and purified human granulocyte/macrophage colony-stimulating factor. This is the first demonstration of a cell line that is capable of differentiation along the basophil lineage and could provide a useful model for examining biochemical and molecular events associated with basophil differentiation.

Basophils↗