Sodium butyrate alleviates fructose-induced non-alcoholic fatty liver disease by remodeling gut microbiota to promoteγ-amino butyric acid production

Sodium butyrate(NaB)can regulate lipid metabolism and inhibit hepatic steatosis.This study aimed to investigate whether NaB can alleviate fructose-induced hepat ic steatosis via remodeling the gut microbiota and evaluate the anti-fatty liver mechanisms.The results showed that NaB and NaB-remodeled gut microbiota significantly alleviated fructose-induced hepatic steatosis and increased plasma uric acid and fructose levels.Furthermore,both NaB and NaB-remodeled gut microbiota increased the abundance of Lactobacillus and altered the levels of plasma amino acids(upregulating gamma-amino butyric acid(GABA)and downregulating L-glutamic acid and L-arginine)in fructose-exposed mice.The correlation analysis showed that GABA levels positively correlated with Lactobacillus abundance,and increased GABA levels might promote the reduction of the hepatic triglyceride content.Further studies confirmed that GABA significantly reduced lipid deposition in mouse hepatocytes induced via fructose pretreatment in vitro.These findings suggested that NaB could ameliorate fructose-induced hepatic steatosis by regulating gut microbiota.

Preparation of Cellulose Acetate Butyrate Porous Micro/Nanofibrous Membranes and Their Properties

Cellulose acetate butyrate(CAB)is a cellulose ester that is commonly used in applications such as coatings and leather brighteners.However,its appearance in a fibrous form is rarely reported.CAB porous micro/nanofibrous membranes with a large number of nanopores on the fiber surface were successfully prepared by electrospinning with dichloromethane(DCM)/acetone(AC)as the mixed solvent.Apparent morphology,porosity,moisture permeability,air permeability,static water contact angles,and thermal conductivity of the fibrous membranes were investigated at different spinning voltages.The results showed that with the increase of the spinning voltage,the average fiber diameter of the CAB porous micro/nanofibrous membranes gradually decreased and the fiber diameter distribution was more uniform.When the spinning voltage reached 40 kV,the porosity reached 91.38%,the moisture permeability was up to 7430 g/(m^(2)·d),the air permeability was up to 36.289 mm/s,the static water contact angle was up to 145.0°,while the thermal conductivity of the fibrous membranes reached 0.030 W/(m·K).The material can be applied as thermal-insulation,waterproof and moisture-permeable membranes.

Sodium butyrate alleviates deoxynivalenol-induced hepatic cholesterol metabolic dysfunction via RORγ-mediated histone acetylation modification in weaning piglets

Background:Cholesterol is an essential component of lipid rafts in cell plasma membrane,which exerts a hepatoprotective role against mycotoxin exposure in pigs,and cholesterol metabolism is vulnerable to epigenetic histone acetylation.Therefore,our present study aimed to investigate whether a histone deacetylase inhibitor(sodium butyrate [NaBu]) could protect the porcine liver from deoxynivalenol(DON) exposure by modulating cholesterol metabolism.Herein,we randomly divided 28 pigs into four groups,which were fed an uncontaminated basal diet,contaminated diet(4 mg DON/kg),uncontaminated diet supplemented with 0.2% NaBu or 4 mg/kg DON contaminated diet(4 mg DON/kg) supplemented with 0.2% NaBu for 28 d.Results:We found that the serum alanine transaminase(ALT),aspartate transaminase(AST),and alkaline phosphatase(ALP) were all increased in pigs exposed to DON,indicative of significant liver injury.Furthermore,the cholesterol content in the serum of DON-exposed pigs was significantly reduced,compared to the healthy Vehicle group.Transcriptome analysis of porcine liver tissues revealed that the cholesterol homeostasis pathway was highly enriched due to DON exposure.In which we validated by qRT-PCR and western blotting that the cholesterol program was markedly activated.Importantly,NaBu effectively restored parameters associated with liver injury,along with the cholesterol content and the expression of key genes involved in the cholesterol biosynthesis pathway.Mechanistically,we performed a ChIP-seq analysis of H3K27ac and showed that NaBu strongly diminished DON-increased H3K27ac genome-wide enrichment.We further validated that the elevated H3K27ac and H3K9ac occupancies on cholesterol biosynthesis genes were both decreased by NaBu,as determined by ChIP-qPCR analysis.Notably,nuclear receptor RORγ,a novel regulator of cholesterol biosynthesis,was found in the hyperacetylated regions.Again,a remarkable increase of RORγ at both mRNA and protein levels in DON-exposed porcine livers was drastically reduced by NaBu.Consistent with RORγ expression,NaBu also hindered RORγ transcriptional binding enrichments on these activated cholesterol biosynthesis genes like HMGCR,SQLE,and DHCR24.Furthermore,we conducted an in vitro luciferase reporter assay to verify that porcine RORγ directly bonds to the promoters of the above target genes.Conclusions:Collectively,our results demonstrate the utility of the natural product Na Bu as a potential anti-mycotoxin nutritional strategy for regulating cholesterol metabolism via RORγ-mediated histone acetylation modification.

The specificity of ten non-digestible carbohydrates to enhance butyrate-producing bacteria and butyrate production in vitro fermentation

Butyrate and butyrate-producing bacteria are important indicators of gut microbial metabolism in human health.Ten non-digestible carbohydrates(NDCs),including inulin,fructooligosaccharide(FOS),oatsβ-glucans(OGS),oatsβ-glucan oligosaccharides(OGOS),Astragalus polysaccharides(APS),Astragalus oligosaccharides(AOS),xanthan gum oligosaccharides(XGOS),gellan gum oligosaccharides(GGOS),curdlan oligosaccharides(COS),and pullulan oligosaccharides(POS)were used to investigate NDC specifi city in modulating butyrate-producing bacteria and butyrate production in 48 h in vitro fermentation studies in combination with fecal inocula from 7 healthy donors and 11 patients with type 2 diabetes(T2D).We observed that the amount of these ten NDCs utilized depended on NDC structure and inter-individual gut microbial differences.XGOS and GGOS fermentations signifi cantly increased butyrate-producing bacteria(especially f_Lachnospiraceae)and butyric acid production.Furthermore,XGOS and GGOS fermentations showed a better ability to consistently modulate gut microbiota composition and metabolic properties between individuals of healthy donors or T2D patients when compared to inulin,FOS,APS,AOS,OGS,OGOS,COS and POS fermentation.This research indicated that xanthan gum and gellan gum oligosaccharides have strong specifi city to enhance butyrate-producing bacteria and butyrate production.

Prospects for clinical applications of butyrate-producing bacteria

As the major source of energy for colonic mucosal cells and as an important regulator of gene expression,inflammation,differentiation,and apoptosis in host cells,microbiota-derived butyrate can enhance the intestinal mucosal immune barrier,modulate systemic immune response,and prevent infections.Maintaining a certain level of butyrate production in the gut can help balance intestinal microbiota,regulate host immune response,and promote the development and maintenance of the intestinal mucosal barrier.Butyrate-producing bacteria act as probiotics and play important roles in a variety of normal biological functions.Bacteriotherapeutic supplementation by using fecal microbiota transplantation to restore butyrate-producing commensal bacteria in the gut has been very successful in the treatment of recurrent and refractory Clostridium difficile(C.difficile)infection or C.difficile-negative nosocomial diarrhea.Administration of probiotics that include butyrate-producing bacteria may have a role in the treatment of inflammatory bowel diseases and in the prevention of necrotizing enterocolitis and late-onset sepsis in premature infants.Furthermore,modulating gut microbiota with dietary approaches may improve intestinal dysbiosis commonly seen in patients with obesity-associated metabolic disorders.Supplementation with a butyrate-producing bacterial stain might be used to increase energy expenditure,improve insulin sensitivity,and to help control obesity and metabolic syndrome.

Sodium butyrate prevents radiation-induced cognitive impairment by restoring pCREB/BDNF expression

Sodium butyrate is a histone deacetylase inhibitor that affects various types of brain damages.To investigate the effects of sodium butyrate on hippocampal dysfunction that occurs after whole-brain irradiation in animal models and the effect of sodium butyrate on radiation exposure-induced cognitive impairments,adult C57BL/6 mice were intraperitoneally treated with 0.6 g/kg sodium butyrate before exposure to 10 Gy cranial irradiation.Cognitive impairment in adult C57BL/6 mice was evaluated via an object recognition test 30 days after irradiation.We also detected the expression levels of neurogenic cell markers(doublecortin)and phosphorylated cAMP response element binding protein/brain-derived neurotrophic factor.Radiation-exposed mice had decreased cognitive function and hippocampal doublecortin and phosphorylated cAMP response element binding protein/brain-derived neurotrophic factor expression.Sodium butyrate pretreatment reversed these changes.These findings suggest that sodium butyrate can improve radiation-induced cognitive dysfunction through inhibiting the decrease in hippocampal phosphorylated cAMP response element binding protein/brain-derived neurotrophic factor expression.The study procedures were approved by the Institutional Animal Care and Use Committee of Korea Institute of Radiological Medical Sciences(approval No.KIRAMS16-0002)on December 30,2016.

Supplementation with sodium butyrate improves growth and antioxidant function in dairy calves before weaning

Background: There is increasing research interest in using short-chain fatty acids(SCFAs) including butyrate as potential alternatives to antibiotic growth promoters in animal production. This study was conducted to evaluate the effects of supplementation of sodium butyrate(SB) in liquid feeds(milk, milk replacer, and the mixture of both)on the growth performance, rumen fermentation, and serum antioxidant capacity and immunoglobins in dairy calves before weaning. Forty healthy female Holstein calves(4-day-old, 40 ± 5 kg of body weight) were housed in individual hutches and randomly allocated to 1 of 4 treatment groups(n = 10 per group) using the RAND function in Excel. The control group was fed no SB(SB0), while the other three groups were supplemented with 15(SB15),30(SB30), or 45(SB45) g/d of SB mixed into liquid feeds offered. The calves were initially fed milk only(days 2 to 20), then a mixture of milk and milk replacer(days 21 to 23), and finally milk replacer only(days 24 to 60).Results: The SB supplementation enhanced growth and improved feed conversion into body weight gain compared with the SB0 group, and the average daily gain increased quadratically with increasing SB supplementation. No significant effect on rumen pH;concentrations of NH_3-N, individual and total VFAs;or acetate:propionate(A:P) ratio was found during the whole experimental period. Serum glutathione peroxidase activity increased linearly with the increased SB supplementation, while the serum concentration of maleic dialdehyde linearly decreased. Serum concentrations of immunoglobulin A, immunoglobulin G, or immunoglobulin M were not affected by the SB supplementation during the whole experimental period.Conclusions: Under the conditions of this study, SB supplementation improved growth performance and antioxidant function in pre-weaned dairy calves. We recommended 45 g/d as the optimal level of SB supplementation mixed into liquid feeds(milk or milk replacer) to improve the growth and antioxidant function of dairy calves before weaning.

CREB-binding protein, p300, butyrate, and Wnt signaling in colorectal cancer

This paper reviews the distinctive roles played by the transcriptional coactivators CREB-binding protein(CBP) and p300 in Wnt/β-catenin signaling and cell physiology in colorectal cancer(CRC). Specifically, we focus on the effects of CBP- and p300-mediated Wnt activity on(1) neoplastic progression;(2) the activities of butyrate, a breakdown product of dietary fiber, on cell signaling and colonic cell physiology;(3) the development of resistance to histone deacetylase inhibitors(HDACis), including butyrate and synthetic HDACis, in colonic cells; and(4) the physiology and number of cancer stem cells. Mutations of the Wnt/β-catenin signaling pathway initiate the majority of CRC cases, and we have shown that hyperactivation of this pathway by butyrate and other HDACis promotes CRC cell apoptosis. This activity by butyrate may in part explain the preventive action of fiber against CRC. However, individuals with a high-fiber diet may still develop neoplasia; therefore, resistance to the chemopreventive action of butyrate likely contributes to CRC. CBP or p300 may modify the ability of butyrate to influence colonic cell physiology since the two transcriptional coactivators affect Wnt signaling, and likely, its hyperactivation by butyrate. Also, CBP and p300 likely affect colonic tumorigenesis, as well as stem cell pluripotency. Improvement of CRC prevention and therapy requires a better understanding of the alterations in Wnt signaling and gene expression that underlie neoplastic progression, stem cell fate, and the development of resistance to butyrate and clinically relevant HDACis. Detailed knowledge of how CBP- and p300 modulate colonic cell physiology may lead to new approaches for anti-CRC prevention and therapeutics, particularly with respect to combinatorial therapy of CBP/p300 inhibitors with HDACis.

Beneficial effect of butyrate, Lactobacillus casei and L-carnitine combination in preference to each in experimental colitis

AIM: To investigate the beneficial effect of the combination of butyrate, Lactobacillus casei, and L-carnitine in a rat colitis model.METHODS: Rats were divided into seven groups. Fourgroups received oral butyrate, L-carnitine, Lactobacillus casei and the combination of three agents for 10 consecutive days. The remaining groups included negative and positive controls and a sham group. Macroscopic, histopathological examinations, and biomarkers such as tumor necrosis factor-alpha(TNF-α) and interlukin-1β(IL-1β), myeloperoxidase(MPO), thiobarbituric acid reactive substances(TBARS), and ferric reduced ability of plasma(FRAP) were determined in the colon.RESULTS: The combination therapy exhibited a significant beneficial effect in alleviation of colitis compared to controls. Overall changes in reduction of TNF-α(114.66 ± 18.26 vs 171.78 ± 9.48 pg/mg protein, P < 0.05), IL-1β(24.9 ± 1.07 vs 33.06 ± 2.16 pg/mg protein, P < 0.05), TBARS(0.2 ± 0.03 vs 0.49 ± 0.04 μg/mg protein, P < 0.01), MPO(15.32 ± 0.4 vs 27.24 ± 3.84 U/mg protein, P < 0.05), and elevation of FRAP(23.46 ± 1.2 vs 15.02 ± 2.37 μmol/L, P < 0.05) support the preference of the combination therapy in comparison to controls. Although the monotherapies were also effective in improvement of colitis markers, the combination therapy was much better in improvement of colon oxidative stress markers including FRAP, TBARS, and MPO.CONCLUSION: The present combination is a suitable mixture in control of experimental colitis and should be trialed in the clinical setting.

Sodium butyrate protects against toxin-induced acute liver failure in rats

BACKGROUND: Acute liver failure(ALF) is a serious clinical syndrome with high mortality. Sodium butyrate has been shown to alleviate organ injury in a wide variety of preclinical models of critical diseases. The aim of this study was to investigate the protective effect of sodium butyrate on ALF in rats.METHODS: All rats were randomly divided into control,model and sodium butyrate treatment groups. Except the control group, the rats were induced ALF animal model by subcutaneous injection of human serum albumin+D- galactosamine+lipopolysaccharide. After induction of ALF,the rats in the treatment group received sodium butyrate(500mg/kg) at 12-hour or 24-hour time point. Fourty-eight hours after ALF induction, the animals were sacrificed and samples were harvested. Serum endotoxin, high mobility group box-1(HMGB1), liver function parameters, tumor necrosis factoralpha(TNF-α) and interferon-gamma(IFN-γ) were measured.The expression of HMGB1 and nuclear factor-kappa B(NF-κB)p65 protein in liver tissue was detected by Western blotting. The histological changes of liver and intestine were examined. The survival duration was also observed.RESULTS: Serum endotoxin, alanine aminotransferase, HMGB1,TNF-α and IFN-γ were significantly increased and the liver histology showed more severe histopathological injury in the model group compared with the control group(P<0.05).Compared to the model group, sodium butyrate treatment significantly improved the histopathological changes in the liver and intestine, reduced serum endotoxin and inflammatory cytokines, suppressed HMGB1 and NF-кB p65 proteins in liver tissue, and prolonged the survival duration regardless of treatment at 12 hours or 24 hours after induction of ALF(P<0.05).CONCLUSIONS: Sodium butyrate protected the liver from toxin-induced ALF in rats. The mechanisms may be due to direct hepatoprotection and decreased intestinal permeability.

Sodium Butyrate Induces Apoptosis of Human Colon Cancer Cells by Modulating ERK and Sphingosine Kinase 2

Objective To investigate the role of extracellular signal-regulated kinase （ERK） in apoptosis of human colon cancer （HCT116） cells. Methods After the HCT116 cells were pretreated with specific ERK inhibitor （U0126） or specific siRNA and exposed to 10 mmol/L sodium butyrate （NaBT） for 24 h, their apoptosis was detected by flow cytometry, levels of SphK2 and ERK protein were measured by Western blot, and translocation of SphK2 was assayed by immunofluorescence microscopy. Results The U0126 and siRNAs specific for SphK2 blocked the export of SphK2 from nuclei to cytoplasm and increased the apoptosis of HCT116 cells following NaBT exposure. Over-expression of PKD decreased NaBT-induced apoptosis of HCT116 cells, which was reversed by U0126. Furthermore, transfection of HCT116 cells with constitutively activated PKD plasmids recovered the UO126-blocked export of SphK2. Conclusion ERK regulates the export of SphK2 and apoptosis of HCT116 cells by modulating PKD. Modulation of these molecules may help increase the sensitivity of colon cancer cells to the physiologic anti-colon cancer agent, NaBT.

Protective effects of sodium butyrate on rotavirus inducing endoplasmic reticulum stress-mediated apoptosis via PERK-eIF2αsignaling pathway in IPEC-J2 cells

Background:Rotavirus(RV)is a major pathogen that causes severe gastroenteritis in infants and young animals.Endoplasmic reticulum(ER)stress and subsequent apoptosis play pivotal role in virus infection.However,the protective mechanisms of intestinal damage caused by RV are poorly defined,especially the molecular pathways related to enterocytes apoptosis.Thus,the aim of this study was to investigate the protective effect and mechanism of sodium butyrate(SB)on RV-induced apoptosis of IPEC-J2 cells.Results:The RV infection led to significant cell apoptosis,increased the expression levels of ER stress(ERS)markers,phosphorylated protein kinase-like ER kinase(PERK),eukaryotic initiation factor 2 alpha(eIF2α),caspase9,and caspase3.Blocking PERK pathway using specific inhibitor GSK subsequently reversed RV-induced cell apoptosis.The SB treatment significantly inhibited RV-induced ERS by decreasing the expression of glucose regulated protein 78(GRP78),PERK,and eIF2α.In addition,SB treatment restrained the ERS-mediated apoptotic pathway,as indicated by downregulation of C/EBP homologous protein(CHOP)mRNA level,as well as decreased cleaved caspase9 and caspase3 protein levels.Furthermore,siRNA-induced GPR109a knockdown significantly suppressed the protective effect of SB on RV-induced cell apoptosis.Conclusions:These results indicate that SB exerts protective effects against RV-induced cell apoptosis through inhibiting ERS mediated apoptosis by regulating PERK-eIF2αsignaling pathway via GPR109a,which provide new ideas for the prevention and control of RV.

Suppression of fibrosis in human pterygium fibroblasts by butyrate and phenylbutyrate

AIM：To evaluate the antifibrogenic effects of butyrate or phenylbutyrate,a chemical derivative of butyrate,in human pterygium fibroblasts.METHODS：Human pterygium fibroblasts obtained from patient pterygium tissue were treated with butyrate or phenylbutyrate for 48h.Expression ofα-smooth muscle actin,collagen I,collagen III and matrix metalloproteinase-1m RNA was measured by quantitative real-time reverse transcription polymerase chain reaction,and acetylated histone was evaluated by Western blotting.RESULTS：Butyrate inhibitedα-smooth muscle actin,type III collagen and matrix metalloproteinase-1 expressions,and phenylbutyrate inhibited types I and III collagen and matrix metalloproteinase-1 expressions without changing cell viability as well as both of these increased histone acetylation.These results suggested that butyrate and phenylbutyrate suppress fibrosis through a mechanism involving histone deacetylase inhibitor.CONCLUSION：This indicates that butyrate or phenylbutyrate have antifibrogenic effects in human pterygium fibroblasts and could be novel types of prophylactic and/or therapeutic drugs for pterygium,especially phenylbutyrate,which does not have the unpleasant smell associated with butyrate.

Butyrate in combination with forskolin alleviates necrotic enteritis,increases feed efficiency,and improves carcass composition of broilers

Background:The emergence of antimicrobial resistance has necessitated the development of effective alternatives to antibiotics for livestock and poultry production.This study investigated a possible synergy between butyrate and forskolin(a natural labdane diterpene)in enhancing innate host defense,barrier function,disease resistance,growth performance,and meat quality of broilers.Methods:The expressions of representative genes involved in host defense(AvBD9 and AvBD10),barrier function(MUC2,CLDN1,and TJP1),and inflammation(IL-1β)were measured in chicken HD11 macrophages in response to butyrate and forskolin in the presence or absence of bacterial lipopolysaccharides(LPS).Intestinal lesions and the Clostridium perfringens titers were also assessed in C.perfringens-challenged chickens fed butyrate and forskolincontaining Coleus forskohlii(CF)extract individually or in combination.Furthermore,growth performance and carcass characteristics were evaluated in broilers supplemented with butyrate and the CF extract for 42 d.Results:Butyrate and forskolin synergistically induced the expressions of AvBD9,AvBD10,and MUC2 in chicken HD11 cells(P<0.05)and the synergy was maintained in the presence of LPS.Butyrate and forskolin also suppressed LPS-induced IL-1βgene expression in HD11 cells in a synergistic manner(P<0.05).The two compounds significantly reduced the intestinal lesions of C.perfringens-challenged chickens when combined(P<0.05),but not individually.Furthermore,butyrate in combination with forskolin-containing CF extract had no influence on weight gain,but significantly reduced feed intake(P<0.05)with a strong tendency to improve feed efficiency(P=0.07)in a 42-d feeding trial.Desirably,the butyrate/forskolin combination significantly decreased abdominal fat deposition(P=0.01)with no impact on the carcass yield,breast meat color,drip loss,or pH of d-42 broilers.Conclusions:Butyrate and forskolin has potential to be developed as novel antibiotic alternatives to improve disease resistance,feed efficiency,and carcass composition of broilers.

Effect and Comparison of Sodium Butyrate and Trichostatin A on the Proliferation/Differentiation of K562

In order to explore the molecular mechanisms of sodium butyrate and trichostatin A on K562 cell proliferation/differentiation, K562 cells were grown in the absence or presence of sodium butyrate or trichostatin A The percentage of viable cells was determined by trypan blue exclusion Differentiation was determined by nitro-blue tetrazolium (NBT) reduction and cell surface adhesion molecules analyzed by FACS Cell cycle distribution was studied after DNA staining by propidium iodide Cell cycle regulatory proteins were detected by Western blot and reverse transcription-polymerase chain reaction The results showed that sodiun butyrate blocked cells mainly at the G0/G1 phase of the cell cycle, whereas trichostatin A arrested the cells at G2 phase Sodium butyrate could down-regulate the mRNA expression of cyclin D1, but not affect its protein expression; down-regulate the protein expression of cyclin D3, but not affect its mRNA expression Trichostatin A showed similar effects on cyclin D1 and D3 as sodium butyrate Both sodium butyrate and trichostatin A could stimulate p21 expression of K562 cells at mRNA and protein levels It may be concluded that sodium butyrate and trichostatin A could promote the proliferation/differentiation of the K562 cells, which might be contributed to the induced expression of cyclin D3 and p21 proteins

The Effect of Sodium Butyrate in Combination with ATRA on the Proliferation/Differentiation of SKM-1

To explore the molecular mechanisms of sodium butyrate working on SKM-1 cell proliferation/differentiation and to study its synergistic effect with all-trans retinoic acid (ATRA), SKM-1 cells were grown in the absence or presence of sodium butyrate and/or ATRA. The percentage of viable cells was determined by trypan blue exclusion. Differentiation was determined by nitroblue tetrazolium (NBT) reduction and cell surface adhesion molecules was analyzed by FACS. Cell cycle distribution was examined after DNA staining by propidium iodide. D-type cyclins, cdks and P21 mRNA were studied by reverse transcription-polymerase chain reaction. Our results showed that sodiun butyrate and/or ATRA blocked cells mainly in the G 0/G 1 phase of the cell cycle. ATRA inhibited the mRNA expression of CDK6, CDK4, cyclinD3 and cyclinD1. Sodium butyrate inhibited the mRNA expression of CDK2, cyclinD2 and cyclinD1. ATRA and sodium butyrate inhibited the mRNA expression of CDK6, CDK4, CDK2, cyclinD1, cyclinD2 and cyclinD3. Both ATRA and/or sodium butyrate stimulated p21 expression at the mRNA levels. Our results suggest that the effect of sodium butyrate on cell proliferation/differentiation might be linked to its ability to induce expression of p21 mRNA and inhibit the cyclin-cdk complexes. Our observations support the notion that the sodium butyrate works synergistically with ATRA.

MODULATION OF MDR-1 GENE IN HUMAN BREAST CANCER CELLS BY SODIUM BUTYRATE AND DMSO

Objective: To analyze the regulation effect of MDR-1 gene in human breast cancer cell by the differentiating agents, sodium butyrate and dimethyl sulfoxide. Methods: 1. A sensitive assay, RT-PCR, was used to measure the mRNA level before and after the treatment of sodium butyrate, DMSO, using β-actin as control; 2. Evaluated the effect of sodium butyrate, DMSO on MDR-1 gene expression of human breast cancer at the protein level by immunoflow cytometry; 3. P-glycoprotein function was examined after accumulation of the fluorescent drug, Phodamine-123, by flow cytometry; 4. Chemosensitivity to doxorubicin was analyzed using the MTT assay. Results: Sodium butyrate and DMSO were found to increase the MDR characteristics on MDR-1 gene, MDR-1 expression levels, P-glycoprotein function and chemosensitivity to doxorubicin. Conclusion: sodium butyrate, DMSO can modulate the MDR-1 gene at gene level, protein level, protein function level and cell level.

Rapid Estimation of Enantioselectivity in Lipase-catalyzed Resolution of Glycidyl Butyrate Using pH Indicator

A simple method for rapid estimation of the enantioselectivity of lipase in resolution of chiral esters is described. The enantioselectivity of lipase can be estimated rapidly through comparing the difference of hydrolysis rates for the racemic ester and its slow reacting enantiomer under the same condition because the difference mainly depends on the enantioselective ratio（E values）. The higher the enantioselectivity of enzyme, the larger the difference of hydrolysis rate. The bromothymol blue（BTB） can be used as pH indicator for microplate reader to monitor the formation of acid in lipase-catalyzed hydrolysis of esters. This method has been successfully used to rapidly estimate the enantioselectivity of several lipases in the resolution of glycidyl butyrate.

Contribution of Decreased Expression of Ku70 to Enhanced Radiosensitivity by Sodium Butyrate in Glioblastoma Cell Line(U251)

The present study investigated the enhanced radiosensitivity of U-251 cells induced by sodium butyrate（NaB） and its possible mechanisms.Increased radiosensitivity of U251 cells was examined by clonogenic cell survival assays.The expression of Ku70 mRNA and protein was detected by using RT-PCR and Western blotting respectively.γ-H2AX foci were measured at different time points after ionizing irradiation alone or combined with NaB treatment.The results showed that cell survival rate was significantly reduced,both D0 and Dq values were decreased（D0：1.43 Gy vs.1.76 Gy;Dq：1.22 Gy vs.2.05 Gy） after the combined treatment as compared with irradiation alone,and sensitivity enhancing ratio（SER） reached 1.23.The average number of γ-H2AX foci per cell receiving the combined treatment was significantly increased at different time points,and the expression levels of Ku70 mRNA and protein were suppressed by NaB in a dose-dependent manner.It was concluded that enhanced radiosensitivity induced by NaB involves an inhibited expression of Ku70 and an increase in γ-H2AX foci,which suggests decreased ability in DSB repair.

Butyrate inhibits the bovine rumen epithelial cell proliferation via downregulation of positive regulators at G0/G1 phase checkpoint

Short-chain fatty acids(SCFAs)butyrate promote the postnatal rumen epithelial development and maturation in ruminants.However,molecular mechanisms of effects of butyrate on the bovine rumen epithelial cells(BRECs)proliferation remain elusive.Therefore,purpose of this study was to investigate the effects of butyrate on the expression of genes and proteins at G0/G1 and S phase of BRECs cycle.Our results showed that BRECs treated with butyrate inhibited(P<0.05)the proliferation of BRECs,relatively to control.Flow cytometric assays revealed that butyrate triggers the BRECs cycle arrest at the G0/G1 phase.qRT-PCR analyses of mRNA level of genes involved in the G0/G1 phase of cell cycle showed that butyrate significantly upregulated(P<0.001)the expression of mRNA encoding p21^(Cip1)compared with control group,but it decreased(P<0.05)the mRNA levels of cyclin D1 and CDK4 genes at G0/G1 phase checkpoint compared with control.Moreover,Western blot also revealed that butyrate downregulated the expression of cyclin D3,CDK6,p-Rb,and E2F1 proteins involved in the modulation of G0/G1 phase of cell cycle.In conclusion,our results demonstrated that butyrate inhibits the proliferation of BRECs via downregulation of positive regulators at G0/G1 phase checkpoint.