The conventional perception of astrocytes as mere supportive cells within the brain has recently been called into question by empirical evidence, which has revealed their active involvement in regulating brain functio...The conventional perception of astrocytes as mere supportive cells within the brain has recently been called into question by empirical evidence, which has revealed their active involvement in regulating brain function and encoding behaviors associated with emotions.Specifically, astrocytes in the basolateral amygdala have been found to play a role in the modulation of anxiety-like behaviors triggered by chronic stress. Nevertheless, the precise molecular mechanisms by which basolateral amygdala astrocytes regulate chronic stress–induced anxiety-like behaviors remain to be fully elucidated. In this study, we found that in a mouse model of anxiety triggered by unpredictable chronic mild stress, the expression of excitatory amino acid transporter 2 was upregulated in the basolateral amygdala. Interestingly, our findings indicate that the targeted knockdown of excitatory amino acid transporter 2 specifically within the basolateral amygdala astrocytes was able to rescue the anxiety-like behavior in mice subjected to stress. Furthermore, we found that the overexpression of excitatory amino acid transporter 2 in the basolateral amygdala, whether achieved through intracranial administration of excitatory amino acid transporter 2agonists or through injection of excitatory amino acid transporter 2-overexpressing viruses with GfaABC1D promoters, evoked anxiety-like behavior in mice. Our single-nucleus RNA sequencing analysis further confirmed that chronic stress induced an upregulation of excitatory amino acid transporter 2 specifically in astrocytes in the basolateral amygdala. Moreover, through in vivo calcium signal recordings, we found that the frequency of calcium activity in the basolateral amygdala of mice subjected to chronic stress was higher compared with normal mice.After knocking down the expression of excitatory amino acid transporter 2 in the basolateral amygdala, the frequency of calcium activity was not significantly increased, and anxiety-like behavior was obviously mitigated. Additionally, administration of an excitatory amino acid transporter 2 inhibitor in the basolateral amygdala yielded a notable reduction in anxiety level among mice subjected to stress. These results suggest that basolateral amygdala astrocytic excitatory amino acid transporter 2 plays a role in in the regulation of unpredictable chronic mild stress-induced anxiety-like behavior by impacting the activity of local glutamatergic neurons, and targeting excitatory amino acid transporter 2 in the basolateral amygdala holds therapeutic promise for addressing anxiety disorders.展开更多
Highly-efficient oxidation of 5-hydroxymethylfurtural(HMF) to 2,5-furandicarboxylic acid(FDCA) at low temperature with air as the oxidant is still challenging.Herein,inspired by the respirato ry electron transport cha...Highly-efficient oxidation of 5-hydroxymethylfurtural(HMF) to 2,5-furandicarboxylic acid(FDCA) at low temperature with air as the oxidant is still challenging.Herein,inspired by the respirato ry electron transport chain(ETC) of living cells mediated by electron carriers,we constructed artificial ETCs and transformed liquid flow fuel cells(LFFCs) to flexible reactors for efficient oxidation of HMF to produce FDCA under mild conditions.This LFFC reactor employed an electrodeposition modified nickel foam as an anode to promote HMF oxidation and(VO_(2))_(2)SO_(4) as a cathode electron carrier to facilitate the electron transfer to air.The reaction rate could be easily controlled by selecting the anode catalyst,adjusting the external loading and changing the cathodic electron carrier or oxidants.A maximal power density of 44.9 mW cm^(-2) at room temperature was achieved,while for FDCA production,short-circuit condition was preferred to achieve quick transfer of electrons.For a single batch operation with 0.1 M initial HMF,FDCA yield reached 97.1%.By fed-batch operation,FDCA concentration reached 144.5 g L^(-1) with a total yield of 96%.Ni^(2+)/Ni^(3+) redox couple was the active species mediating the electron transfer,while both experimental and DFT calculation results indicated that HMFCA pathway was the preferred reaction mechanism.展开更多
Aim Prenatal stress （PS） can lead to abnormal behavior of offspring and increase the incidence of mental illness. Previous researches have shown that levels of glutamate and its receptor expression are closely relat...Aim Prenatal stress （PS） can lead to abnormal behavior of offspring and increase the incidence of mental illness. Previous researches have shown that levels of glutamate and its receptor expression are closely relat- ed to the occurrence of this phenomenon. Furthermore, recent study has demonstrated that the expression levels of excitatory amino acid transporters 2 （EAAT2） in different brain regions of 1 month PS offspring rats have changed. Methods The SD pregnant rats were used restraint stress to imitate PS from gestation 14 -~ 19 days. Offspring rats were weaned 21 days after birth. The expression of EAAT2 of hippocampus was observed by Western blot. Results The expression of EAAT2 of 1 month PS offspring rats was significantly decreased in comparison to control group. However, the expression of EAAT2 of 2 month PS offspring rats was significantly increased in comparison to 1 month PS offspring rats. Conclusion These phenomena have illustrated that the expression of EAAT2 of PS off- spring rats could show time dependence or reversibility. The expression of EAAT2 may play an important role in the development of mental illness of offspring rats influenced by PS.展开更多
Monocarboxylic acid transporter 2 （MCT2） transports pyruvate and lactate outside and inside of sperms, mainly as energy sources and plays roles in the regulation of spermatogenesis. We investigated the association a...Monocarboxylic acid transporter 2 （MCT2） transports pyruvate and lactate outside and inside of sperms, mainly as energy sources and plays roles in the regulation of spermatogenesis. We investigated the association among genetic variations in the MCT2 gene, male infertility and MCT2 expression levels in sperm. The functional and genetic significance of the intron 2 （＋28201A 〉 G, rs10506398） and 3＇ untranslated region （UTR） single nucleotide polymorphism （SNP） （＋2626G 〉 A, rs10506399） of MCT2 variants were investigated. Two MCT2 polymorphisms were associated with male infertility （n = 471, P 〈 0.05）. In particular, the MCT2-3＇ UTR SNP （＋2626 G 〉 A） had a strong association with the oligoasthenoteratozoospermia （OAT） group. The ＋2626GG type had an almost 2.4-fold higher sperm count than that of the ＋2626AA type （＋2626GG; 66 x 106 vs ＋2626AA; 27 x 106, P 〈 0.0001）. The MCT2-3＇ UTR SNP may be important for expression, as it is located at the MCT2 3＇ UTR. The average MCT2 protein amount in sperm of the ＋2626GG type was about two times higher than that of the ＋2626AA type. The results suggest that genetic variation in MCT2 has functional and clinical relevance with male infertility.展开更多
目的探讨Lipofermata通过抑制脂肪酸转运蛋白2(fatty acid transport protein 2,FATP2)对小鼠人乳腺癌MDA-MB-231移植瘤生长的影响及其机制。方法通过小鼠构建人乳腺癌移植瘤模型后随机分成实验组(10只)和对照组(10只),实验组小鼠皮下注...目的探讨Lipofermata通过抑制脂肪酸转运蛋白2(fatty acid transport protein 2,FATP2)对小鼠人乳腺癌MDA-MB-231移植瘤生长的影响及其机制。方法通过小鼠构建人乳腺癌移植瘤模型后随机分成实验组(10只)和对照组(10只),实验组小鼠皮下注射Lipofermata,2 mg/kg,每天两次,连续给药2周。对照组小鼠皮下注射溶媒(10%DMSO)2 mg/kg,每天两次,连续给药2周。给药后第8天、第11天、第14天、第17天使用游标卡尺测量并计算各组小鼠移植瘤的体积。给药结束后,取两组小鼠脾脏组织制作组织匀浆,检测各组小鼠脾脏内花生四烯酸(Arachidonicacid,AA)和前列腺素E2的含量。取两组小鼠脾脏组织和肿瘤组织,研磨形成单个细胞,过筛除去多余组织块,流式细胞仪检测CD8+T细胞占总细胞的比例。结果给药后第8天,实验组小鼠移植瘤体积(904.55±62.50)mm 3,对照组小鼠移植瘤体积(907.21±11.07)mm 3,两组无显著差异(t=-0.13,P=0.90)。第11天、第14天及第17天测量发现,实验组小鼠移植瘤体积明显小于对照组,且差异均有统计学意义(P<0.01)。实验组小鼠脾脏内花生四烯酸含量(23.98±1.65)ng/mL,对照组为(45.63±1.85)ng/mL,差异有统计学意义(t=-27.62,P<0.01)。实验组小鼠脾脏内前列腺素E2含量(0.98±0.24)ng/mL,对照组为(1.62±0.18)ng/mL,差异有统计学意义(t=-6.76,P<0.01)。实验组小鼠脾脏内CD8+T细胞比例(0.42±0.07)%,对照组(0.27±0.05)%,差异有统计学意义(t=5.68,P<0.01)。实验组小鼠肿瘤组织内CD8+T细胞比例(0.24±0.06)%,对照组(0.13±0.04)%,差异有统计学意义(t=4.65,P<0.01)。结论Lipofermata通过靶向抑制FATP2来解除髓系抑制细胞(Myeloid-derived suppressor cells,MDSCs)的免疫抑制,提高CD8+T细胞,从而抑制小鼠人乳腺癌MDA-MB-231移植瘤的生长。展开更多
BACKGROUND Colorectal cancer(CRC)is a worldwide problem,which has been associated with changes in diet and lifestyle pattern.As a result of colonic fermentation of dietary fibres,short chain free fatty acids are gener...BACKGROUND Colorectal cancer(CRC)is a worldwide problem,which has been associated with changes in diet and lifestyle pattern.As a result of colonic fermentation of dietary fibres,short chain free fatty acids are generated which activate free fatty acid receptors(FFAR)2 and 3.FFAR2 and FFAR3 genes are abundantly expressed in colonic epithelium and play an important role in the metabolic homeostasis of colonic epithelial cells.Earlier studies point to the involvement of FFAR2 in colorectal carcinogenesis.AIM To understand the role of short chain FFARs in CRC.METHODS Transcriptome analysis console software was used to analyse microarray data from CRC patients and cell lines.We employed short-hairpin RNA mediated down regulation of FFAR2 and FFAR3 genes,which was validated using quantitative real time polymerase chain reaction.Assays for glucose uptake and cyclic adenosine monophosphate(cAMP)generation was done along with immunofluorescence studies to study the effects of FFAR2/FFAR3 knockdown.For measuring cell proliferation,we employed real time electrical impedancebased assay available from xCELLigence.RESULTS Microarray data analysis of CRC patient samples showed a significant down regulation of FFAR2 gene expression.This prompted us to study the FFAR2 in CRC.Since,FFAR3 shares significant structural and functional homology with FFAR2,we knocked down both these receptors in CRC cell line HCT 116.These modified cell lines exhibited higher proliferation rate and were found to have increased glucose uptake as well as increased level of glucose transporter 1.Since,FFAR2 and FFAR3 signal through G protein subunit(Gαi),knockdown of these receptors was associated with increased cAMP.Inhibition of protein kinase A(PKA)did not alter the growth and proliferation of these cells indicating a mechanism independent of cAMP/PKA pathway.CONCLUSION Our results suggest role of FFAR2/FFAR3 genes in increased proliferation of colon cancer cells via enhanced glucose uptake and exclude the role of PKA mediated cAMP signalling.Alternate pathways could be involved that would ultimately result in increased cell proliferation as a result of down regulated FFAR2/FFAR3 genes.This study paves the way to understand the mechanism of action of short chain FFARs in CRC.展开更多
Objective This study aimed to investigate the effects of caprylic acid(C8:0)on lipid metabolism and inflammation,and examine the mechanisms underlying these effects in mice and cells.Methods Fifty-six 6-week-old male ...Objective This study aimed to investigate the effects of caprylic acid(C8:0)on lipid metabolism and inflammation,and examine the mechanisms underlying these effects in mice and cells.Methods Fifty-six 6-week-old male C57BL/6J mice were randomly allocated to four groups fed a highfat diet(HFD)without or with 2%C8:0,palmitic acid(C16:0)or eicosapentaenoic acid(EPA).RAW246.7 cells were randomly divided into five groups:normal,lipopolysaccharide(LPS),LPS+C8:0,LPS+EPA and LPS+cAMP.The serum lipid profiles,inflammatory biomolecules,and ABCA1 and JAK2/STAT3 mRNA and protein expression were measured.Results C8:0 decreased TC and LDL-C,and increased the HDL-C/LDL-C ratio after injection of LPS.Without LPS,it decreased TC in mice(P<0.05).Moreover,C8:0 decreased the inflammatory response after LPS treatment in both mice and cells(P<0.05).Mechanistic investigations in C57BL/6J mouse aortas after injection of LPS indicated that C8:0 resulted in higher ABCA1 and JAK2/STAT3 expression than that with HFD,C16:0 and EPA,and resulted in lower TNF-α,NF-κB mRNA expression than that with HFD(P<0.05).In RAW 264.7 cells,C8:0 resulted in lower expression of pNF-κBP65 than that in the LPS group,and higher protein expression of ABCA1,p-JAK2 and p-STAT3 than that in the LPS and LPS+cAMP groups(P<0.05).Conclusion Our studies demonstrated that C8:0 may play an important role in lipid metabolism and the inflammatory response,and the mechanism may be associated with ABCA1 and the p-JAK2/p-STAT3 signaling pathway.展开更多
Objective This study was conducted to examine the absorption and translocation of conjugated bile acids(BAs)in Calculus bovis and its substitutes to detect differences in these materials.Methods A Caco-2 monolayer cel...Objective This study was conducted to examine the absorption and translocation of conjugated bile acids(BAs)in Calculus bovis and its substitutes to detect differences in these materials.Methods A Caco-2 monolayer cell model was used to compare the apparent permeability coefficient(Papp)value and efflux ratio(ER)of BAs in natural cow-bezoar(NCB),artificial cow-bezoar(ACB),and in vitro cultured cow-bezoar(Ivt-CCB).Papp and ER values were determined by liquid chromatography-mass spectrometry.Samples were separated on an analytical column.Results The distribution of BAs in NCB was significantly different from that in ACB and Ivt-CCB.The percentages of conjugated BAs were significantly higher in NCB than in the two substitutes.The distribution differences of conjugated and unconjugated BAs can be used to distinguish costly NCB from relatively inexpensive substitutes.Conclusion The transport characteristics of BAs in Ivt-CCB were more consistent with NCB than with ACB,even when the proportions of BAs in Ivt-CCB were closer to those of ACB.展开更多
Objective: Persons with type 2 diabetes have increased incidence of hyperuricemia and gout. The hypothesis that Urate transporter 1 (URAT1) levels are increased in type 2 diabetic Zucker rats and this is responsible f...Objective: Persons with type 2 diabetes have increased incidence of hyperuricemia and gout. The hypothesis that Urate transporter 1 (URAT1) levels are increased in type 2 diabetic Zucker rats and this is responsible for elevation of uric acid was tested. Methods: Male 12-week-old obese Zucker rats were compared to non-diabetic lean counterparts. Plasma glucose, uric acid and creatinine were measured. URAT1 protein levels in the renal cortex and medulla were determined by Western blot. Immunohistochemistry was used to determine the location of URAT1 inrenal tubules. Results: Plasma glucose and uric acid levels were higher in the diabetic rats. There was no difference in plasma createnine. URAT1 antibody-positive bands of 27, 31, 50, 62 and 70 kDa were observed in cortex. A similar pattern was observed in medulla with addition of a 44 kDa band. No differences were observed in URAT1 proteins in the cortex between obese and lean rats. In the medulla, expression of the 44 and 50 kDa proteins was higher in lean rats. Expression of 27, 50, 62 kDa URAT1 proteins in the cortex was higher than in the medulla, while expression of the 70 kDa URAT1 was higher in medulla than in cortex. Localization of URAT1 did not differ between groups and included tubules in both cortex and medulla. Conclusions: In male Zucker rats, URAT1 protein expression was observed in both kidney cortex and medulla. Uric acid elevation in the obese group was associated with decreases in the 44 and 50 kDa URAT1 proteins in renal medulla.展开更多
The ability of tetrandrine (Tet), an alkaloid isolated from Radix Stephaniae Tetrandrae, to reduce cortical neuronal injury in cortical cultures derived from fetal rats was quantitatively assessed by examination of mo...The ability of tetrandrine (Tet), an alkaloid isolated from Radix Stephaniae Tetrandrae, to reduce cortical neuronal injury in cortical cultures derived from fetal rats was quantitatively assessed by examination of morphological changes and measurement of lactate dehydrogenase (LDH) released to the extracellular bathing media Cell cultures exposed to the excitatory amino acids (EAA) 50 μmol L 1 glutamate (Glu), 20 μmol L 1 N methyl D aspartate (NMDA), 300 μmol·L 1 β N oxalylamino L alanine (BMAA, NMDA receptor agonist) or 20 μmol·L 1 β N oxaly lamino L alanine (BOAA, non NMDA receptor agonist) for 24 h at 37℃ showed widespread neuronal injury Tet had little effect on the injury induced by 20 μmol·L 1 NMDA but 10 7 and 10 6 μmol·L 1 Tet did partially attenuate the neuronal degeneration, neuronal loss and LDH efflux resulting from prolonged exposures to 100 μmol·L 1 Glu, 300 μmol·L 1 BMAA and 20 μmol·L 1 BOAA respectively The ability of Tet to reduce the neuronal injury induced by prolonged exposure to EAA may contribute, at least in part, to the reduction of Ca 2+ influx through inhibiting the opening of voltagegated Ca 2+ channels Another mechanism that Tet might have a little inhibitory effect on NMDA receptor on neuronal membrane cannot be excluded, as BMAA has been considered to act as a weak NMDA receptor agonist展开更多
基金supported by the National Natural Science Foundation of China,Nos.32371070 (to JT),31761163005 (to JT),32100824 (to QX)the Shenzhen Science and Technology Program,Nos.RCBS20210609104606024 (to QX),JCY20210324101813035 (to DL)+4 种基金the Guangdong Provincial Key S&T Program,No.2018B030336001 (to JT)the Key Basic Research Program of Shenzhen Science and Technology Innovation Commission,Nos.JCYJ20200109115405930 (to JT),JCYJ20220818101615033 (to DL),JCYJ20210324115811031 (to QX),JCYJ20200109150717745 (to QX)Shenzhen Key Laboratory of Neuroimmunomodulation for Neurological Diseases,No.ZDSYS20220304163558001 (to JT)Guangdong Provincial Key Laboratory of Brain Connectome and Behavior,No.2023B1212060055 (to JT)the China Postdoctoral Science Foundation,No.2021M693298 (to QX)。
文摘The conventional perception of astrocytes as mere supportive cells within the brain has recently been called into question by empirical evidence, which has revealed their active involvement in regulating brain function and encoding behaviors associated with emotions.Specifically, astrocytes in the basolateral amygdala have been found to play a role in the modulation of anxiety-like behaviors triggered by chronic stress. Nevertheless, the precise molecular mechanisms by which basolateral amygdala astrocytes regulate chronic stress–induced anxiety-like behaviors remain to be fully elucidated. In this study, we found that in a mouse model of anxiety triggered by unpredictable chronic mild stress, the expression of excitatory amino acid transporter 2 was upregulated in the basolateral amygdala. Interestingly, our findings indicate that the targeted knockdown of excitatory amino acid transporter 2 specifically within the basolateral amygdala astrocytes was able to rescue the anxiety-like behavior in mice subjected to stress. Furthermore, we found that the overexpression of excitatory amino acid transporter 2 in the basolateral amygdala, whether achieved through intracranial administration of excitatory amino acid transporter 2agonists or through injection of excitatory amino acid transporter 2-overexpressing viruses with GfaABC1D promoters, evoked anxiety-like behavior in mice. Our single-nucleus RNA sequencing analysis further confirmed that chronic stress induced an upregulation of excitatory amino acid transporter 2 specifically in astrocytes in the basolateral amygdala. Moreover, through in vivo calcium signal recordings, we found that the frequency of calcium activity in the basolateral amygdala of mice subjected to chronic stress was higher compared with normal mice.After knocking down the expression of excitatory amino acid transporter 2 in the basolateral amygdala, the frequency of calcium activity was not significantly increased, and anxiety-like behavior was obviously mitigated. Additionally, administration of an excitatory amino acid transporter 2 inhibitor in the basolateral amygdala yielded a notable reduction in anxiety level among mice subjected to stress. These results suggest that basolateral amygdala astrocytic excitatory amino acid transporter 2 plays a role in in the regulation of unpredictable chronic mild stress-induced anxiety-like behavior by impacting the activity of local glutamatergic neurons, and targeting excitatory amino acid transporter 2 in the basolateral amygdala holds therapeutic promise for addressing anxiety disorders.
基金supported by the National Key R&D Program of China(2022YFA2105900)the National Natural Science Foundation of China(22178197)。
文摘Highly-efficient oxidation of 5-hydroxymethylfurtural(HMF) to 2,5-furandicarboxylic acid(FDCA) at low temperature with air as the oxidant is still challenging.Herein,inspired by the respirato ry electron transport chain(ETC) of living cells mediated by electron carriers,we constructed artificial ETCs and transformed liquid flow fuel cells(LFFCs) to flexible reactors for efficient oxidation of HMF to produce FDCA under mild conditions.This LFFC reactor employed an electrodeposition modified nickel foam as an anode to promote HMF oxidation and(VO_(2))_(2)SO_(4) as a cathode electron carrier to facilitate the electron transfer to air.The reaction rate could be easily controlled by selecting the anode catalyst,adjusting the external loading and changing the cathodic electron carrier or oxidants.A maximal power density of 44.9 mW cm^(-2) at room temperature was achieved,while for FDCA production,short-circuit condition was preferred to achieve quick transfer of electrons.For a single batch operation with 0.1 M initial HMF,FDCA yield reached 97.1%.By fed-batch operation,FDCA concentration reached 144.5 g L^(-1) with a total yield of 96%.Ni^(2+)/Ni^(3+) redox couple was the active species mediating the electron transfer,while both experimental and DFT calculation results indicated that HMFCA pathway was the preferred reaction mechanism.
文摘Aim Prenatal stress （PS） can lead to abnormal behavior of offspring and increase the incidence of mental illness. Previous researches have shown that levels of glutamate and its receptor expression are closely relat- ed to the occurrence of this phenomenon. Furthermore, recent study has demonstrated that the expression levels of excitatory amino acid transporters 2 （EAAT2） in different brain regions of 1 month PS offspring rats have changed. Methods The SD pregnant rats were used restraint stress to imitate PS from gestation 14 -~ 19 days. Offspring rats were weaned 21 days after birth. The expression of EAAT2 of hippocampus was observed by Western blot. Results The expression of EAAT2 of 1 month PS offspring rats was significantly decreased in comparison to control group. However, the expression of EAAT2 of 2 month PS offspring rats was significantly increased in comparison to 1 month PS offspring rats. Conclusion These phenomena have illustrated that the expression of EAAT2 of PS off- spring rats could show time dependence or reversibility. The expression of EAAT2 may play an important role in the development of mental illness of offspring rats influenced by PS.
文摘Monocarboxylic acid transporter 2 （MCT2） transports pyruvate and lactate outside and inside of sperms, mainly as energy sources and plays roles in the regulation of spermatogenesis. We investigated the association among genetic variations in the MCT2 gene, male infertility and MCT2 expression levels in sperm. The functional and genetic significance of the intron 2 （＋28201A 〉 G, rs10506398） and 3＇ untranslated region （UTR） single nucleotide polymorphism （SNP） （＋2626G 〉 A, rs10506399） of MCT2 variants were investigated. Two MCT2 polymorphisms were associated with male infertility （n = 471, P 〈 0.05）. In particular, the MCT2-3＇ UTR SNP （＋2626 G 〉 A） had a strong association with the oligoasthenoteratozoospermia （OAT） group. The ＋2626GG type had an almost 2.4-fold higher sperm count than that of the ＋2626AA type （＋2626GG; 66 x 106 vs ＋2626AA; 27 x 106, P 〈 0.0001）. The MCT2-3＇ UTR SNP may be important for expression, as it is located at the MCT2 3＇ UTR. The average MCT2 protein amount in sperm of the ＋2626GG type was about two times higher than that of the ＋2626AA type. The results suggest that genetic variation in MCT2 has functional and clinical relevance with male infertility.
文摘BACKGROUND Colorectal cancer(CRC)is a worldwide problem,which has been associated with changes in diet and lifestyle pattern.As a result of colonic fermentation of dietary fibres,short chain free fatty acids are generated which activate free fatty acid receptors(FFAR)2 and 3.FFAR2 and FFAR3 genes are abundantly expressed in colonic epithelium and play an important role in the metabolic homeostasis of colonic epithelial cells.Earlier studies point to the involvement of FFAR2 in colorectal carcinogenesis.AIM To understand the role of short chain FFARs in CRC.METHODS Transcriptome analysis console software was used to analyse microarray data from CRC patients and cell lines.We employed short-hairpin RNA mediated down regulation of FFAR2 and FFAR3 genes,which was validated using quantitative real time polymerase chain reaction.Assays for glucose uptake and cyclic adenosine monophosphate(cAMP)generation was done along with immunofluorescence studies to study the effects of FFAR2/FFAR3 knockdown.For measuring cell proliferation,we employed real time electrical impedancebased assay available from xCELLigence.RESULTS Microarray data analysis of CRC patient samples showed a significant down regulation of FFAR2 gene expression.This prompted us to study the FFAR2 in CRC.Since,FFAR3 shares significant structural and functional homology with FFAR2,we knocked down both these receptors in CRC cell line HCT 116.These modified cell lines exhibited higher proliferation rate and were found to have increased glucose uptake as well as increased level of glucose transporter 1.Since,FFAR2 and FFAR3 signal through G protein subunit(Gαi),knockdown of these receptors was associated with increased cAMP.Inhibition of protein kinase A(PKA)did not alter the growth and proliferation of these cells indicating a mechanism independent of cAMP/PKA pathway.CONCLUSION Our results suggest role of FFAR2/FFAR3 genes in increased proliferation of colon cancer cells via enhanced glucose uptake and exclude the role of PKA mediated cAMP signalling.Alternate pathways could be involved that would ultimately result in increased cell proliferation as a result of down regulated FFAR2/FFAR3 genes.This study paves the way to understand the mechanism of action of short chain FFARs in CRC.
基金supported by the National Natural Science Fund of China[no.81703204].
文摘Objective This study aimed to investigate the effects of caprylic acid(C8:0)on lipid metabolism and inflammation,and examine the mechanisms underlying these effects in mice and cells.Methods Fifty-six 6-week-old male C57BL/6J mice were randomly allocated to four groups fed a highfat diet(HFD)without or with 2%C8:0,palmitic acid(C16:0)or eicosapentaenoic acid(EPA).RAW246.7 cells were randomly divided into five groups:normal,lipopolysaccharide(LPS),LPS+C8:0,LPS+EPA and LPS+cAMP.The serum lipid profiles,inflammatory biomolecules,and ABCA1 and JAK2/STAT3 mRNA and protein expression were measured.Results C8:0 decreased TC and LDL-C,and increased the HDL-C/LDL-C ratio after injection of LPS.Without LPS,it decreased TC in mice(P<0.05).Moreover,C8:0 decreased the inflammatory response after LPS treatment in both mice and cells(P<0.05).Mechanistic investigations in C57BL/6J mouse aortas after injection of LPS indicated that C8:0 resulted in higher ABCA1 and JAK2/STAT3 expression than that with HFD,C16:0 and EPA,and resulted in lower TNF-α,NF-κB mRNA expression than that with HFD(P<0.05).In RAW 264.7 cells,C8:0 resulted in lower expression of pNF-κBP65 than that in the LPS group,and higher protein expression of ABCA1,p-JAK2 and p-STAT3 than that in the LPS and LPS+cAMP groups(P<0.05).Conclusion Our studies demonstrated that C8:0 may play an important role in lipid metabolism and the inflammatory response,and the mechanism may be associated with ABCA1 and the p-JAK2/p-STAT3 signaling pathway.
基金support from the Youth Development Research Foundation of NIFDC(2014A1)National Science and Technology Major Project(2017ZX09101002-002-008)the National Natural Science Foundation of China(No.81403171 and No.81603517)
文摘Objective This study was conducted to examine the absorption and translocation of conjugated bile acids(BAs)in Calculus bovis and its substitutes to detect differences in these materials.Methods A Caco-2 monolayer cell model was used to compare the apparent permeability coefficient(Papp)value and efflux ratio(ER)of BAs in natural cow-bezoar(NCB),artificial cow-bezoar(ACB),and in vitro cultured cow-bezoar(Ivt-CCB).Papp and ER values were determined by liquid chromatography-mass spectrometry.Samples were separated on an analytical column.Results The distribution of BAs in NCB was significantly different from that in ACB and Ivt-CCB.The percentages of conjugated BAs were significantly higher in NCB than in the two substitutes.The distribution differences of conjugated and unconjugated BAs can be used to distinguish costly NCB from relatively inexpensive substitutes.Conclusion The transport characteristics of BAs in Ivt-CCB were more consistent with NCB than with ACB,even when the proportions of BAs in Ivt-CCB were closer to those of ACB.
文摘Objective: Persons with type 2 diabetes have increased incidence of hyperuricemia and gout. The hypothesis that Urate transporter 1 (URAT1) levels are increased in type 2 diabetic Zucker rats and this is responsible for elevation of uric acid was tested. Methods: Male 12-week-old obese Zucker rats were compared to non-diabetic lean counterparts. Plasma glucose, uric acid and creatinine were measured. URAT1 protein levels in the renal cortex and medulla were determined by Western blot. Immunohistochemistry was used to determine the location of URAT1 inrenal tubules. Results: Plasma glucose and uric acid levels were higher in the diabetic rats. There was no difference in plasma createnine. URAT1 antibody-positive bands of 27, 31, 50, 62 and 70 kDa were observed in cortex. A similar pattern was observed in medulla with addition of a 44 kDa band. No differences were observed in URAT1 proteins in the cortex between obese and lean rats. In the medulla, expression of the 44 and 50 kDa proteins was higher in lean rats. Expression of 27, 50, 62 kDa URAT1 proteins in the cortex was higher than in the medulla, while expression of the 70 kDa URAT1 was higher in medulla than in cortex. Localization of URAT1 did not differ between groups and included tubules in both cortex and medulla. Conclusions: In male Zucker rats, URAT1 protein expression was observed in both kidney cortex and medulla. Uric acid elevation in the obese group was associated with decreases in the 44 and 50 kDa URAT1 proteins in renal medulla.
文摘The ability of tetrandrine (Tet), an alkaloid isolated from Radix Stephaniae Tetrandrae, to reduce cortical neuronal injury in cortical cultures derived from fetal rats was quantitatively assessed by examination of morphological changes and measurement of lactate dehydrogenase (LDH) released to the extracellular bathing media Cell cultures exposed to the excitatory amino acids (EAA) 50 μmol L 1 glutamate (Glu), 20 μmol L 1 N methyl D aspartate (NMDA), 300 μmol·L 1 β N oxalylamino L alanine (BMAA, NMDA receptor agonist) or 20 μmol·L 1 β N oxaly lamino L alanine (BOAA, non NMDA receptor agonist) for 24 h at 37℃ showed widespread neuronal injury Tet had little effect on the injury induced by 20 μmol·L 1 NMDA but 10 7 and 10 6 μmol·L 1 Tet did partially attenuate the neuronal degeneration, neuronal loss and LDH efflux resulting from prolonged exposures to 100 μmol·L 1 Glu, 300 μmol·L 1 BMAA and 20 μmol·L 1 BOAA respectively The ability of Tet to reduce the neuronal injury induced by prolonged exposure to EAA may contribute, at least in part, to the reduction of Ca 2+ influx through inhibiting the opening of voltagegated Ca 2+ channels Another mechanism that Tet might have a little inhibitory effect on NMDA receptor on neuronal membrane cannot be excluded, as BMAA has been considered to act as a weak NMDA receptor agonist
