Fatty acids are energy substrates and cell components which participate in regulating signal transduction,transcription factor activity and secretion of bioactive lipid mediators.The acyl-CoA synthetases(ACSs)family c...Fatty acids are energy substrates and cell components which participate in regulating signal transduction,transcription factor activity and secretion of bioactive lipid mediators.The acyl-CoA synthetases(ACSs)family containing 26 family members exhibits tissue-specific distribution,distinct fatty acid substrate preferences and diverse biological functions.Increasing evidence indicates that dysregulation of fatty acid metabolism in the liver-gut axis,designated as the bidirectional relationship between the gut,microbiome and liver,is closely associated with a range of human diseases including metabolic disorders,inflammatory disease and carcinoma in the gastrointestinal tract and liver.In this review,we depict the role of ACSs in fatty acid metabolism,possible molecular mechanisms through which they exert functions,and their involvement in hepatocellular and colorectal carcinoma,with particular attention paid to long-chain fatty acids and small-chain fatty acids.Additionally,the liver-gut communication and the liver and gut intersection with the microbiome as well as diseases related to microbiota imbalance in the liver-gut axis are addressed.Moreover,the development of potentially therapeutic small molecules,proteins and compounds targeting ACSs in cancer treatment is summarized.展开更多
Many enzymes which catalyze the conversion of large substrates are made of several structural domains belonging to the same polypeptide chain. Transfer RNA (tRNA), one of the substrates of the multidomain aminoacyl-tR...Many enzymes which catalyze the conversion of large substrates are made of several structural domains belonging to the same polypeptide chain. Transfer RNA (tRNA), one of the substrates of the multidomain aminoacyl-tRNA synthetases (aaRS), is an L-shaped molecule whose size in one dimension is similar to that of its cognate aaRS. Crystallographic structures of aaRS/tRNA complexes show that these enzymes use several of their structural domains to interact with their cognate tRNA. This mini review discusses first some aspects of the evolution and of the flexibility of the pentadomain bacterial glutamyl-tRNA synthetase (GluRS) revealed by kinetic and interaction studies of complementary truncated forms, and then illustrates how stable analogues of aminoacyl-AMP intermediates have been used to probe conformational changes in the active sites of Escherichia coli GluRS and of the nondiscriminating aspartyl-tRNA synthetase (ND-AspRS) of Pseudomonas aeruginosa.展开更多
Objectives: In the present study, we have sought to establish the clinical and immunological characteristics of Japanese patients with interstitial lung disease (ILD). Methods: Serum samples from 35 patients of ILD we...Objectives: In the present study, we have sought to establish the clinical and immunological characteristics of Japanese patients with interstitial lung disease (ILD). Methods: Serum samples from 35 patients of ILD were screened for autoantibodies using RNA and protein immunoprecipitation assays. Patients with or without serum antibodies to aminoacyl tRNA synthetases (ARS) were assessed clinically and compared. Results: Sera from 12 of 35 (34%) patients with ILD (mean age at onset = 49.7 yrs;range 27 - 65 yrs) were found to contain anti-ARS antibodies (anti-EJ: 3 patients;anti-OJ: 2 patients;anti-PL-12: 3 patients;anti-KS: 4 patients). Nine of the 12 (75%) were female. Six (50%) had Raynaud’s phenomenon, 5 (42%) had arthralgia/arthritis and four (33%) had rheumatoid factor. Lung biopsy specimens of 8 patients with anti-ARS antibodies were examined histologically in detail. The following was determined: Two patients had usual interstitial pneumonia;3 had non-specific interstitial pneumonia;one had organizing pneumonia;one had lymphocyte interstitial pneumonia and the remaining patient had desquamative interstitial pneumonia. Age at disease onset was significantly lower and the frequency of Raynaud’s phenomenon was significantly greater in these patients compared to anti-ARS-negative patients (49.7 yrs vs. 62.6 yrs, p = 0.004;50% vs. 4%, p = 0.003, respectively). Conclusions: These results indicate that the presence of anti-ARS autoantibodies correlates with ILD without definite diagnosis of connective tissue diseases as well as polymyositis/dermatomyositis (PM/DM) with ILD in Japanese patients.展开更多
Aminoacyl-t RNA synthetases（Amino ARSs） are essential enzymes that perform the first step of protein synthesis. Beyond their original roles, Amino ARSs possess non-canonical functions, such as cell cycle regulation ...Aminoacyl-t RNA synthetases（Amino ARSs） are essential enzymes that perform the first step of protein synthesis. Beyond their original roles, Amino ARSs possess non-canonical functions, such as cell cycle regulation and signal transduction. Therefore, Amino ARSs represent a powerful pharmaceutical target if their non-canonical functions can be controlled. Using Amino ARSs-specific primers, we screened m RNA expression in the spinal cord dorsal horn of rats with peripheral nerve injury created by sciatic nerve axotomy. Of 20 Amino ARSs, we found that phenylalanyl-t RNA synthetase beta chain（FARSB）, isoleucyl-t RNA synthetase（IARS） and methionyl-t RNA synthetase（MARS） m RNA expression was increased in spinal dorsal horn neurons on the injured side, but not in glial cells. These findings suggest the possibility that FARSB, IARS and MARS, as a neurotransmitter, may transfer abnormal sensory signals after peripheral nerve damage and become a new target for drug treatment.展开更多
Ergopeptines or their derivatives are widely used for treating neurodegenerative and cerebrovascular diseases.The nonribosomal peptide synthetasedD-lysergyl peptide synthetase A(LPSA)determines ergopeptine formation b...Ergopeptines or their derivatives are widely used for treating neurodegenerative and cerebrovascular diseases.The nonribosomal peptide synthetasedD-lysergyl peptide synthetase A(LPSA)determines ergopeptine formation but the detailed mechanism remains to be elucidated.Here,we characterized two LPSAs from Claviceps purpurea Cp-1 strain through heterologous expression in Aspergillus nidulans feeding with D-lysergic acid.We proved that Cp-LPSA1 catalyzed the formation of ergocornine,a-ergocryptine,and b-ergocryptine,precisely controlled by the substrate specificity of its three modules.Cp-LPSA2 was initially inactive but could be restored to catalyze a-ergosine formation.Using this platform,we validated that P1-LPSA1 and P1-LPSA2 from the reported C.purpurea P1 strain catalyzed ergotamine and a-ergocryptine formation,respectively.Typically,the nonribosomal peptide codes implicated in every module of the LPSAs were defined and elucidated,in which certain key residues could play a switched role for substrate specificity and product interconversion.By constructing chimeric LPSAs through module assembly,the production of the desired ergopeptines was achieved.Notably,1.46 mg/L of a-ergocryptine and 1.09 mg/L of ergotamine were produced respectively by mixed-culture of C.paspali No.24(fermentation supernatant)and the recombinants of A.nidulans.Our findings provide insights into the biosynthetic mechanism of ergopeptines and lay a foundation for directed ergopeptine biosynthesis.展开更多
Heptoses are important structural components of Gram-negative bacterium cell wall and participate in bacterial colonization,infection,and immune recognition.Current knowledge of NDP-heptose originating from D-sedohept...Heptoses are important structural components of Gram-negative bacterium cell wall and participate in bacterial colonization,infection,and immune recognition.Current knowledge of NDP-heptose originating from D-sedoheptulose 7-phosphate in Grampositive bacterium remains limited.Here,in silico analysis suggested that the special tridomain NDP-heptose synthetases with isomerase,kinase,and nucleotidyltransferase activities are conservatively distributed in Actinobacteria class of Gram-positive bacterium.Enzymatical characterization of the tridomain proteins from different strains showed that they are involved in ADPD-glycero-β-D-manno-heptose biosynthesis despite the unexpected discovery of kinase activities deficient in some proteins.The presence of three types of NDP-heptose synthetases in Gram-positive bacterium suggests that it is also a rich source of heptoses and the heptose moieties may play important roles in vivo.Our work updates the understanding of NDP-heptose biosynthesis in Gram-positive bacterium and lays a solid foundation for further physiological function explorations.展开更多
Long-range electrostatic interactions in proteins/peptides associating to nucleic acids are reflected in the salt-dependence of the binding process.According to the oligocationic binding model,which is based on counte...Long-range electrostatic interactions in proteins/peptides associating to nucleic acids are reflected in the salt-dependence of the binding process.According to the oligocationic binding model,which is based on counterion condensation theory,only the cationic residues of peptides/proteins near the binding interface are assumed to affect the salt dependence in the association of peptides and proteins to nucleic acids.This model has been used to interpret and predict the binding of oligocationic chains-such as oligoarginines/lysines-to nucleic acids,and does an excellent job in these kinds of systems.This simple relationship,which is used to compare or count the number of ionic interactions in protein-nucleic acid complexes,does not hold when acidic residues,i.e.glutamate and aspartate,are incorporated in the protein matrix.Here,we report a combined molecular mechanics(by means of energy-minimization of the structure under the influence of an empirical energy function)and Poisson-Boltzmann(PB)study on the salt-dependence in binding to tRNA of two important enzymes that are involved in the seminal step of peptide formation in the ribosome:Glutamine synthetase(GluRS)and Glutaminyl synthetase(GlnRS)bound to their cognate tRNA.These two proteins are anionic and contain a significant number of acidic residues distributed over the entire protein.Some of these residues are located in the binding interface to tRNA.We computed the salt-dependence in association,SKpred,of these enzyme-tRNA complexes using both the linear and nonlinear solution to the PoissonBoltzmann Equation(PBE).Our findings demonstrate that the SKpred obtained with the nonlinear PBE is in good agreement with the experimental SKobs,while use of the linear PBE resulted in the SKpred being anomalous.We conclude that electrostatic interactions between the binding partners in these systems are less favorable by means of charge-charge repulsion between negatively charged protein residues and phosphateoxygens in the tRNA backbone but also play a significant role in the association process of proteins to tRNA.Some unfavorable electrostatic interactions are probably compensated by hydrogen-bonds between the carboxylate group of the side chain in the interfacial acidic protein residues and the tRNA backbone.We propose that the low experimentally observed SKobs values for both GlnRS-and GluRS-tRNA depend on the distribution and number of anionic residues that exist in these tRNA synthetases.Our computed electrostatic binding free energies were large and unfavorable due to the Coulombic and de-solvation contribution for the GlnRS-tRNA and GluRS-tRNA complexes,respectively.Thus,low SKobs values may not reflect small contributions from the electrostatic contribution in complex-formation,as is often suggested in the literature.When charges are”turned off”in a computer-experiment,our results indicated that”turning off”acidic residues far from a phosphate group significantly influences SKpred.If cationic residues are“turned off”,less impact on SKpred is observed with respect to the distance to the nearest phosphate-group。展开更多
BACKGROUND Hepatocellular carcinoma(HCC)is a significant global health challenge with rising incidence rates and poor prognoses.Aminoacyl-tRNA synthetases(ARSs)are important regulators implicated in the occurrence and...BACKGROUND Hepatocellular carcinoma(HCC)is a significant global health challenge with rising incidence rates and poor prognoses.Aminoacyl-tRNA synthetases(ARSs)are important regulators implicated in the occurrence and progression of several cancers.However,their specific function in HCC remains unclear,and ARSs-related prognostic factors for patient stratification are lacking.AIM To investigate the ARSs-related mechanisms of HCC and establish an effective prognostic risk model for stratifying patients with HCC.METHODS We screened ARSs genes of interest using differential gene expression,mutation,and survival analysis.Western blot and Immunohistochemistry were used to analyze MARS1 expression in the liver tissues of patients with HCC.Functional studies,including CCK-8 cell viability assay,EdU cell proliferation assay,cell cycle assays,Transwell migration and invasion assays,and in vivo tumor xenograft models,were conducted to comprehensively elucidate the specific role of MARS1 in HCC.Moreover,the MARS1-related prognostic score(MRPS)was established by LASSO regression and Cox regression analysis in The Cancer Genome Atlas-HCC and GSE14520 cohorts.Patients’immunotherapy and chemotherapy responses were predicted by immunomicroenvironment and drug susceptibility analysis in both subgroups.RESULTS MARS1 was selected as a target gene from a series of ARSs genes,with markedly higher expression observed in HCC tissues compared to adjacent non-cancerous tissues.Silencing MARS1 considerably impeded the proliferation,migration,invasion,and tumorigenic abilities of HCC cells in vitro and in vivo.Moreover,high MRPSs were associated with poor overall survival,altered infiltration of T cells,macrophages,monocytes,elevated immune checkpoint expression(PD-L1,CTLA4,LAG3),and reduced drug sensitivity in HCC.CONCLUSION MARS1 promotes HCC development and represents a potential therapeutic target for HCC management.Furthermore,MRPS serves as an independent prognostic factor for survival and a predictor of tumor treatment response.展开更多
BACKGROUND Ferroptosis is a newly recognized form of regulated cell death characterized by iron-dependent accumulation of lipid reactive oxygen species.It has been extensively studied in various diseases,including can...BACKGROUND Ferroptosis is a newly recognized form of regulated cell death characterized by iron-dependent accumulation of lipid reactive oxygen species.It has been extensively studied in various diseases,including cancer,Parkinson’s disease,and stroke.However,its precise role and underlying mechanisms in ischemia/reperfusion injury,particularly in the intestinal ischemia-reperfusion(IIR),remain unclear.In current work,we aimed to investigate the participation of histone lactylation during IIR progression.AIM To investigate the role of mitochondrial alanyl-tRNA synthetase 2(AARS2)in ferroptosis and its epigenetic regulation of acyl-CoA synthetase long-chain family member 4(ACSL4)through histone lactylation during IIR injury.METHODS We established a mouse model to mimic IIR and conducted AARS2 knockdown as treatment.The expression of AARS2 in intestinal tissues was measured by western blot.The integrity of intestinal tissues was detected by hematoxylin and eosin staining,serum fatty acid-binding protein,protein levels of ZO-1 and occluding.An in vitro hypoxia-reperfusion(H/R)cell model was established,and cell viability was measured by CCK-8.The in vitro and in vivo ferroptosis was determined by the accumulation of Fe2+and malondialdehyde(MDA).The epigenetic regulation of ACSL4 by AARS2 was detected by chromatin immunoprecipitation(ChIP)assay and luciferase reporter assay.RESULTS We observed a notable elevated AARS2 level in intestinal tissue of mice in IIR model group,which was reversed by shAARS2 treatment.Knockdown of AARS2 repressed alleviated intestinal barrier disruption and repressed the accumulation of ferroptosis biomarker Fe2+and MDA during IIR.The in vitro results showed that shAARS2 alleviated impaired cell viability caused by H/R,as well as repressed ferroptosis.Knockdown of AARS2 notably downregulated the RNA and protein expression of ACSL4.Mechanistically,knockdown of AARS2 downregulated the enrichment of H3K18 La modification on AARS2,as well as suppressed its promoter activity.Overexpression of AARS2 could abolish the protective effects of shACSL4 in vitro.CONCLUSION The elevation of AARS2 during IIR led to cell ferroptosis via epigenetically upregulating the expression of ACSL4.Our findings presented AARS2 as a promising therapeutic target for IIR.展开更多
Black rice,as a dietary supplement,has received increasing attention because of its beneficial health properties.Although black rice and its major ingredients have been considered a potential therapy for ulcerative co...Black rice,as a dietary supplement,has received increasing attention because of its beneficial health properties.Although black rice and its major ingredients have been considered a potential therapy for ulcerative colitis(UC),its effect and underlying mechanism of action remain obscure.In this study,black rice was demonstrated to improve dextran sulfate sodium salt(DSS)-induced UC and restore intestinal barrier dysfunction.Cyanidin 3-O-glucoside(C3G)is the most abundant ingredient in black rice.Similarly,in vivo and in vitro studies have demonstrated that C3G alleviates colitis and intestinal barrier dysfunction.Proteomic analysis showed that C3G significantly reduced abnormallyelevated swiprosin-1 levels in mice with colitis.Furthermore,the effect of C3G on mitigating colitis was inhibited after swiprosin-1 was overexpressed in intestinal tissue in vivo and Caco-2 cells in vitro.Acyl-CoA synthetase long-chain family member 1(ACSL1)was identified as a potential protein that interacts with swiprosin-1 byco-immunoprecipitation and liquid chromatography-tandem mass spectrometry.By integratingmetabolomics experiments and bioinformatics analysis of single-cell sequencing,ACSL1 was found to selectively bind to swiprosin-1 and regulate downstream linoleic acid metabolism in colitis.Moreover,C3G was observed to prevent the localization of ACSL1 within mitochondria via swiprosin-1,thereby inhibiting the oxidation of linoleic acid.This study demonstrated that C3G targeted swiprosin-1 to ameliorate UC via ASCLl-mediated linoleic acid metabolism,thereby providing a novel potential insight into the mechanism of C3G protection against colitis and establishing the groundwork for its clinical application.展开更多
In rice (Oryza sativa L.) roots two glutamine synthetase (GS) isozymes, GSra and GSrb, were identified recently in the author's experiments, but the homology of both GSra and GSrb as well as their localization in ...In rice (Oryza sativa L.) roots two glutamine synthetase (GS) isozymes, GSra and GSrb, were identified recently in the author's experiments, but the homology of both GSra and GSrb as well as their localization in the rice roots are unclear. In the present study, the purified GSra and GSrb from rice roots were used to immunize rabbits to obtain the respective antibodies. The immunodiffusion and immunoblotting experiments showed that the antibody against GSra or GSrb was specific for GS and its isozymes. The immunoprecipitation test indicated that the antibody of GSra or GSrb not only recognized its respective antigen, but also well recognized each other's antigen. GSra or GSrb antibody recognized also better cytosolic GS1 of rice leaves, but the recognization for chloroplast GS2 from rice or spinach (Spinacia oleracea Mill.) leaves was weaker. Our results indicate that GSra and GSrb from rice roots are quite similar in antigenicity and are extremely similar proteins and that both GSra and GSrb may also be a form of cytosolic GS just as the cytosolic GS1 of rice leaves.展开更多
[Objective] The mRNA expression level changes of S-adenosylmethionine synthetase （SAMS） under low temperature stress was studied. [Method] Total RNA were extracted from leaves, stem and earthnut of sweet potato 0,12...[Objective] The mRNA expression level changes of S-adenosylmethionine synthetase （SAMS） under low temperature stress was studied. [Method] Total RNA were extracted from leaves, stem and earthnut of sweet potato 0,12,24,48 and 72 h after low temperature treatement, mRNA expression level was analyzed by reverse expression and Real-time PCR technique. [Result] The expression quality of the gene extracted from leaves, stem and earthnut increased and the expression quality reached the peak point 24,72 and 72 h after low temperature treatment respectively. The expression change of earthnut was the biggest. [Conclusion] Low temperature was good for increasing mRNA expression of relevart genes.展开更多
The regeneration ability of four alfalfa （Medicago sativa L.） cultivars, Xinjiang Daye, Longdong, Gannong 1 and Gannong 3, was studied, and the effects of various cultivars, explant sources and medium recipes on reg...The regeneration ability of four alfalfa （Medicago sativa L.） cultivars, Xinjiang Daye, Longdong, Gannong 1 and Gannong 3, was studied, and the effects of various cultivars, explant sources and medium recipes on regeneration were compared. The better callus forming frequency obtained from hypocotyls of Xinjiang Daye is 88.5% and regeneration frequency is 9.8% in our initial experiments. To further optimize regeneration system for genetic transformation, we therefore changed concentrations of plant growth regulators and supplemented with glutamine into callus-induction and shoot-regeneration media. Callus forming frequency and shoot differentiation frequency were increased to 100%. The time taken to generate transgenic plants （16 weeks） was shorter than that for previouse procedure （25 weeks） and regeneration frequency was promoted to 15.1%. The results show that addition of glutamine is particularly important for shortening period of regeneration and promoting regeneration frequency. For study of genetic transformation of alfalfa, Agrobacterium tumefaciens-mediated transformation of Xinjiang Daye was developed based on this optimized regeneration system. The plant expression vector carrying two glutamine synthetases （GS 1 and GS2） and △1-pyrroline-5-carboxylate synthetase （P5CS） gene was used for alfalfa in vitro transformation. Six transgenic alfalfa plantlets with resistance to PPT were obtained. The introduction of foreign genes into plants was assessed in the transformants by PCR analysis and Southern hybridizations.展开更多
Enterovirus 71(EV71) caused hand, foot and mouth disease(HFMD) is a serious threat to the health of young children. Although type I interferon(IFN-I) has been proven to control EV71 replication, the key downstream IFN...Enterovirus 71(EV71) caused hand, foot and mouth disease(HFMD) is a serious threat to the health of young children. Although type I interferon(IFN-I) has been proven to control EV71 replication, the key downstream IFNstimulated gene(ISG) remains to be clarified and investigated. Recently, we found that 2’-5’-oligoadenylate synthetases 3(OAS3), as one of ISG of IFN-β1b, was antagonized by EV71 3C protein. Here, we confirm that OAS3is the major determinant of IFN-β1b-mediated EV71 inhibition, which depends on the downstream constitutive RNase L activation. 2’-5’-oligoadenylate(2-5A) synthesis activity deficient mutations of OAS3 D816A, D818A,D888A, and K950A lost resistance to EV71 because they could not activate downstream RNase L. Further investigation proved that EV71 infection induced OAS3 but not RNase L expression by IFN pathway. Mechanically, EV71 or IFN-β1b-induced phosphorylation of STAT1, but not STAT3, initiated the transcription of OAS3 by directly binding to the OAS3 promoter. Our works elucidate the immune regulatory mechanism of the host OAS3/RNase L system against EV71 replication.展开更多
Long-chain acyl-Co A synthetase(ACSL) family members include five different ACSL isoforms, each encoded by a separate gene and have multiple spliced variants. ACSLs on endoplasmic reticulum and mitochondrial outer mem...Long-chain acyl-Co A synthetase(ACSL) family members include five different ACSL isoforms, each encoded by a separate gene and have multiple spliced variants. ACSLs on endoplasmic reticulum and mitochondrial outer membrance catalyze fatty acids with chain lengths from 12 to 20 carbon atoms to form acyl-Co As, which are lipid metabolic intermediates and involved in fatty acid metabolism, membrane modifications and various physiological processes. Gain- or lossof-function studies have shown that the expression of individual ACSL isoforms can alter the distribution and amount of intracellular fatty acids. Changes in the types and amounts of fatty acids, in turn, can alter the expression of intracellular ACSLs. ACSL family members affect not only the proliferation of normal cells, but the proliferation of malignant tumor cells. They also regulate cell apoptosis through different signaling pathways and molecular mechanisms. ACSL members have individual functions in fatty acid metabolism in different types of cells depending on substrate preferences, subcellular location and tissue specificity, thus contributing to liver diseases and metabolic diseases, such as fatty liver disease, obesity, atherosclerosis and diabetes. They are also linked to neurological disorders and other diseases. However, the mechanisms are unclear. This review addresses new findings in the classification and properties of ACSLs and the fatty acid metabolismassociated effects of ACSLs in diseases.展开更多
AIM:To evaluate effects of UDP-glucuronosyltransferase1A1(UGT1A1) and thymidylate synthetase(TS) gene polymorphisms on irinotecan in metastatic colorectal cancer(mCRC).METHODS:Two irinotecan-and fluorouracil-based reg...AIM:To evaluate effects of UDP-glucuronosyltransferase1A1(UGT1A1) and thymidylate synthetase(TS) gene polymorphisms on irinotecan in metastatic colorectal cancer(mCRC).METHODS:Two irinotecan-and fluorouracil-based regimens,FOLFIRI and IFL,were selected as second-line therapy for 138 Chinese mCRC patients.Genomic DNA was extracted from peripheral blood samples before treatment.UGT1A1 and TS gene polymorphisms were determined by direct sequencing and restriction fragment length polymorphism,respectively.Gene polymorphisms of UGT1A1*28,UGT1A1*6 and promoter enhancer region of TS were analyzed.The relationship between genetic polymorphisms and clinical outcome,that is,response,toxicity and survival were assessed.Pharmacokinetic analyses were performed in a subgroup patients based on different UGT1A1 genotypes.Plasma concentration of irinotecan and its active metabolite SN-38 and inactive metabolite SN-38G were determined by high performance liquid chromatography.Differences in irinotecan and its metabolites between UGT1A1 gene variants were compared.RESULTS:One hundred and eight patients received the FOLFIRI regimen,29 the IFL regimen,and one irinotecan monotherapy.One hundred and thirty patients were eligible for toxicity and 111 for efficacy evaluation.One hundred and thirty-six patients were tested for UGT1A1*28 and *6 genotypes and 125 for promoter enhancer region of TS.Patients showed a higher frequency of wild-type UGT1A1*28(TA6/6) compared with a Caucasian population(69.9% vs 45.2%).No significant difference was found between response rates and UGT1A1 genotype,although wild-type showed lower response rates compared with other variants(17.9% vs 24.2% for UGT1A1*28,15.7% vs 26.8% for UGT1A1*6).When TS was considered,the subgroup with homozygous UGT1A1*28(TA7/7) and non-3RG genotypes showed the highest response rate(33.3%),while wild-type UGT1A1*28(TA6/6) with non-3RG only had a 13.6% response rate,but no significant difference was found.Logistic regression showed treatment duration was closely linked to clinical response.In toxicity comparison,UGT1A1*28 TA6/6 was associated with lower incidence of grade 2-4 diarrhea(27.8% vs 100%),and significantly reduced the risk of grade 4 neutropenia compared with TA7/7(7.8% vs 37.5%).Wild-type UGT1A1*6(G/G) tended to have a lower incidence of grade 3/4 diarrhea vs homozygous mutant(A/A) genotype(13.0% vs 40.0%).Taking UGT1A1 and TS genotypes together,lower incidence of grade 2-4 diarrhea was found in patients with non-3RG TS genotypes,when TA6/6 was compared with TA7/7(35.3% vs 100.0%).No significant association with time to progression(TTP) and overall survival(OS) was observed with either UGT1A1 or TS gene polymorphisms,although slightly longer TTP and OS were found with UGT1A1*28(TA6/6).Irinotecan PK was investigated in 34 patients,which showed high area under concentration curve(AUC) of irinotecan and SN-38,but low AUC ratio(SN-38G /SN-38) in those patients with UGT1A1*28 TA7/7.CONCLUSION:A distinct distribution pattern of UGT1A1 genotypes in Chinese patients might contribute to relatively low toxicity associated with irinotecan and 5-fluorouracil in mCRC patients.展开更多
Real-time polymerase chain reaction analysis was used to compare the effect of NO3^- on the activities of nitrate reductase （NR） and glutamine synthetase （GS）, and the transcript levels of two NR genes, OsNial and...Real-time polymerase chain reaction analysis was used to compare the effect of NO3^- on the activities of nitrate reductase （NR） and glutamine synthetase （GS）, and the transcript levels of two NR genes, OsNial and OsNia2, two cytosolic GS1 genes, OsGln1;1 and OsGln1;2, and one plastid GS2 gene OsGln2, in two rice （Oryza sativa L.） cultivars Nanguang （NG） and Yunjing （Y J）. Both cultivars achieved greater biomass and higher total N concentration when grown in a mixed N supply than in sole NH4^＋ nutrition. Supply of NO3^- increased NR activity in both leaves and roots. Expression of both NR genes was also substantially enhanced and transcript levels of OsNia2 were significantly higher than those of OsNial. NO3 also caused an increase in GS activity, but had a complex effect on the expression of the three GS genes. In roots, the OsGln1;1 transcript increased, but OsGln1;2 decreased. In leaves, NO3^- had no effect on the GS1 expression, but the transcript for OsGln2 increased both in the leaves and roots of rice with a mixed supply of N. These results suggested that the increase in GS activity might be a result of the complicated regulation of the various GS genes. In addition, the NO3-induced increase of biomass, NR activity, GS activity, and the transcript levels of NR and GS genes were proportionally higher in NG than in Y J, indicating a stronger response of NG to NO3^- nutrition than YJ.展开更多
The objective is to study whether the accumulation and utilization of plant N are controlled by Mo status in winter wheat cultivars. Mo-efficient cultivar 97003 （eft） and Mo-inefficient cultivar 97014 （ineff） were...The objective is to study whether the accumulation and utilization of plant N are controlled by Mo status in winter wheat cultivars. Mo-efficient cultivar 97003 （eft） and Mo-inefficient cultivar 97014 （ineff） were grown in severely Mo-deficient acidic soil （Tamm-reagent-extractable Mo 0.112 mg kg^-1） with （＋Mo） and without （-Mo） the application of 0.13 mg kg^-1 Mo. The accumulation and use efficiency of plant total N were significantly higher in ＋Mo than that in -Mo and in eft than that in ineff under Mo deficiency. N use efficiency was remarkably higher in maturity but it was forwarded to jointing stage after Mo supply, thus indicating that Mo supply promoted the N use efficiency besides N uptake and eff was efficient in N uptake and utilization. The overall activity of nitrate reductase （NR, EC 1.6.6.1） was significantly higher in ＋Mo than in -Mo and ratio of ＋Mo/-Mo was even to 14.8 at filleting stage for ineff. Activity of glutamine synthetase （GS, EC 6.3.1.2） was significantly lower in ＋Mo than in -Mo. Concentration of nitrate and glutamate were also significantly lower in ＋Mo than in -Mo, thus provided evidences for enhancing N use efficiency by Mo supply. Activities of NR and GS were significantly higher and concentrations of nitrate and glutamate were significantly lower in eff than ineff under Mo deficiency, thus indicated eff was more efficient in N reduction and utilization. It is therefore concluded that Mo could promote N accumulation and utilization in winter wheat which was directly related to NR and feedback regulated by GS. Higher Mo status also results in higher accumulation and utilization of plant N in eft.展开更多
基金Supported by the Interdisziplinäres Zentrum für Klinische Forschung(IZKF-MSP-06)of University Hospital Jena.
文摘Fatty acids are energy substrates and cell components which participate in regulating signal transduction,transcription factor activity and secretion of bioactive lipid mediators.The acyl-CoA synthetases(ACSs)family containing 26 family members exhibits tissue-specific distribution,distinct fatty acid substrate preferences and diverse biological functions.Increasing evidence indicates that dysregulation of fatty acid metabolism in the liver-gut axis,designated as the bidirectional relationship between the gut,microbiome and liver,is closely associated with a range of human diseases including metabolic disorders,inflammatory disease and carcinoma in the gastrointestinal tract and liver.In this review,we depict the role of ACSs in fatty acid metabolism,possible molecular mechanisms through which they exert functions,and their involvement in hepatocellular and colorectal carcinoma,with particular attention paid to long-chain fatty acids and small-chain fatty acids.Additionally,the liver-gut communication and the liver and gut intersection with the microbiome as well as diseases related to microbiota imbalance in the liver-gut axis are addressed.Moreover,the development of potentially therapeutic small molecules,proteins and compounds targeting ACSs in cancer treatment is summarized.
文摘Many enzymes which catalyze the conversion of large substrates are made of several structural domains belonging to the same polypeptide chain. Transfer RNA (tRNA), one of the substrates of the multidomain aminoacyl-tRNA synthetases (aaRS), is an L-shaped molecule whose size in one dimension is similar to that of its cognate aaRS. Crystallographic structures of aaRS/tRNA complexes show that these enzymes use several of their structural domains to interact with their cognate tRNA. This mini review discusses first some aspects of the evolution and of the flexibility of the pentadomain bacterial glutamyl-tRNA synthetase (GluRS) revealed by kinetic and interaction studies of complementary truncated forms, and then illustrates how stable analogues of aminoacyl-AMP intermediates have been used to probe conformational changes in the active sites of Escherichia coli GluRS and of the nondiscriminating aspartyl-tRNA synthetase (ND-AspRS) of Pseudomonas aeruginosa.
文摘Objectives: In the present study, we have sought to establish the clinical and immunological characteristics of Japanese patients with interstitial lung disease (ILD). Methods: Serum samples from 35 patients of ILD were screened for autoantibodies using RNA and protein immunoprecipitation assays. Patients with or without serum antibodies to aminoacyl tRNA synthetases (ARS) were assessed clinically and compared. Results: Sera from 12 of 35 (34%) patients with ILD (mean age at onset = 49.7 yrs;range 27 - 65 yrs) were found to contain anti-ARS antibodies (anti-EJ: 3 patients;anti-OJ: 2 patients;anti-PL-12: 3 patients;anti-KS: 4 patients). Nine of the 12 (75%) were female. Six (50%) had Raynaud’s phenomenon, 5 (42%) had arthralgia/arthritis and four (33%) had rheumatoid factor. Lung biopsy specimens of 8 patients with anti-ARS antibodies were examined histologically in detail. The following was determined: Two patients had usual interstitial pneumonia;3 had non-specific interstitial pneumonia;one had organizing pneumonia;one had lymphocyte interstitial pneumonia and the remaining patient had desquamative interstitial pneumonia. Age at disease onset was significantly lower and the frequency of Raynaud’s phenomenon was significantly greater in these patients compared to anti-ARS-negative patients (49.7 yrs vs. 62.6 yrs, p = 0.004;50% vs. 4%, p = 0.003, respectively). Conclusions: These results indicate that the presence of anti-ARS autoantibodies correlates with ILD without definite diagnosis of connective tissue diseases as well as polymyositis/dermatomyositis (PM/DM) with ILD in Japanese patients.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT and Future Planning(2015R1A2A2A01002735 to JJ2015R1C1A1A02036863 to NYJ)
文摘Aminoacyl-t RNA synthetases（Amino ARSs） are essential enzymes that perform the first step of protein synthesis. Beyond their original roles, Amino ARSs possess non-canonical functions, such as cell cycle regulation and signal transduction. Therefore, Amino ARSs represent a powerful pharmaceutical target if their non-canonical functions can be controlled. Using Amino ARSs-specific primers, we screened m RNA expression in the spinal cord dorsal horn of rats with peripheral nerve injury created by sciatic nerve axotomy. Of 20 Amino ARSs, we found that phenylalanyl-t RNA synthetase beta chain（FARSB）, isoleucyl-t RNA synthetase（IARS） and methionyl-t RNA synthetase（MARS） m RNA expression was increased in spinal dorsal horn neurons on the injured side, but not in glial cells. These findings suggest the possibility that FARSB, IARS and MARS, as a neurotransmitter, may transfer abnormal sensory signals after peripheral nerve damage and become a new target for drug treatment.
基金supported by the Beijing Natural Science Foundation(Grant no.7252205)the CAMS Innovation Fund for Medical Sciences(Grant no.CIFMS2021-I2M-1-029)the National Natural Science Foundation of China(Grant no.81603002).
文摘Ergopeptines or their derivatives are widely used for treating neurodegenerative and cerebrovascular diseases.The nonribosomal peptide synthetasedD-lysergyl peptide synthetase A(LPSA)determines ergopeptine formation but the detailed mechanism remains to be elucidated.Here,we characterized two LPSAs from Claviceps purpurea Cp-1 strain through heterologous expression in Aspergillus nidulans feeding with D-lysergic acid.We proved that Cp-LPSA1 catalyzed the formation of ergocornine,a-ergocryptine,and b-ergocryptine,precisely controlled by the substrate specificity of its three modules.Cp-LPSA2 was initially inactive but could be restored to catalyze a-ergosine formation.Using this platform,we validated that P1-LPSA1 and P1-LPSA2 from the reported C.purpurea P1 strain catalyzed ergotamine and a-ergocryptine formation,respectively.Typically,the nonribosomal peptide codes implicated in every module of the LPSAs were defined and elucidated,in which certain key residues could play a switched role for substrate specificity and product interconversion.By constructing chimeric LPSAs through module assembly,the production of the desired ergopeptines was achieved.Notably,1.46 mg/L of a-ergocryptine and 1.09 mg/L of ergotamine were produced respectively by mixed-culture of C.paspali No.24(fermentation supernatant)and the recombinants of A.nidulans.Our findings provide insights into the biosynthetic mechanism of ergopeptines and lay a foundation for directed ergopeptine biosynthesis.
基金supported in part by the National Key R&D Program of China(2020YFA0907700)the National Natural Science Foundation of China(32025002)the Center for Ocean Mega-Science,CAS(KEXUE2019GZ05)。
文摘Heptoses are important structural components of Gram-negative bacterium cell wall and participate in bacterial colonization,infection,and immune recognition.Current knowledge of NDP-heptose originating from D-sedoheptulose 7-phosphate in Grampositive bacterium remains limited.Here,in silico analysis suggested that the special tridomain NDP-heptose synthetases with isomerase,kinase,and nucleotidyltransferase activities are conservatively distributed in Actinobacteria class of Gram-positive bacterium.Enzymatical characterization of the tridomain proteins from different strains showed that they are involved in ADPD-glycero-β-D-manno-heptose biosynthesis despite the unexpected discovery of kinase activities deficient in some proteins.The presence of three types of NDP-heptose synthetases in Gram-positive bacterium suggests that it is also a rich source of heptoses and the heptose moieties may play important roles in vivo.Our work updates the understanding of NDP-heptose biosynthesis in Gram-positive bacterium and lays a solid foundation for further physiological function explorations.
基金NSF-CHEM-0137961(to MOF)and in part by the Institute for Mathematics and its Applications with funds provided by the National Science Foundation.
文摘Long-range electrostatic interactions in proteins/peptides associating to nucleic acids are reflected in the salt-dependence of the binding process.According to the oligocationic binding model,which is based on counterion condensation theory,only the cationic residues of peptides/proteins near the binding interface are assumed to affect the salt dependence in the association of peptides and proteins to nucleic acids.This model has been used to interpret and predict the binding of oligocationic chains-such as oligoarginines/lysines-to nucleic acids,and does an excellent job in these kinds of systems.This simple relationship,which is used to compare or count the number of ionic interactions in protein-nucleic acid complexes,does not hold when acidic residues,i.e.glutamate and aspartate,are incorporated in the protein matrix.Here,we report a combined molecular mechanics(by means of energy-minimization of the structure under the influence of an empirical energy function)and Poisson-Boltzmann(PB)study on the salt-dependence in binding to tRNA of two important enzymes that are involved in the seminal step of peptide formation in the ribosome:Glutamine synthetase(GluRS)and Glutaminyl synthetase(GlnRS)bound to their cognate tRNA.These two proteins are anionic and contain a significant number of acidic residues distributed over the entire protein.Some of these residues are located in the binding interface to tRNA.We computed the salt-dependence in association,SKpred,of these enzyme-tRNA complexes using both the linear and nonlinear solution to the PoissonBoltzmann Equation(PBE).Our findings demonstrate that the SKpred obtained with the nonlinear PBE is in good agreement with the experimental SKobs,while use of the linear PBE resulted in the SKpred being anomalous.We conclude that electrostatic interactions between the binding partners in these systems are less favorable by means of charge-charge repulsion between negatively charged protein residues and phosphateoxygens in the tRNA backbone but also play a significant role in the association process of proteins to tRNA.Some unfavorable electrostatic interactions are probably compensated by hydrogen-bonds between the carboxylate group of the side chain in the interfacial acidic protein residues and the tRNA backbone.We propose that the low experimentally observed SKobs values for both GlnRS-and GluRS-tRNA depend on the distribution and number of anionic residues that exist in these tRNA synthetases.Our computed electrostatic binding free energies were large and unfavorable due to the Coulombic and de-solvation contribution for the GlnRS-tRNA and GluRS-tRNA complexes,respectively.Thus,low SKobs values may not reflect small contributions from the electrostatic contribution in complex-formation,as is often suggested in the literature.When charges are”turned off”in a computer-experiment,our results indicated that”turning off”acidic residues far from a phosphate group significantly influences SKpred.If cationic residues are“turned off”,less impact on SKpred is observed with respect to the distance to the nearest phosphate-group。
基金Supported by National Natural Science Foundation of China,No.82300694 and No.81970523Natural Science Foundation of Hunan Province,No.2022JJ70165,No.2021JJ31067,No.2023JJ40828 and No.2022JJ40704.
文摘BACKGROUND Hepatocellular carcinoma(HCC)is a significant global health challenge with rising incidence rates and poor prognoses.Aminoacyl-tRNA synthetases(ARSs)are important regulators implicated in the occurrence and progression of several cancers.However,their specific function in HCC remains unclear,and ARSs-related prognostic factors for patient stratification are lacking.AIM To investigate the ARSs-related mechanisms of HCC and establish an effective prognostic risk model for stratifying patients with HCC.METHODS We screened ARSs genes of interest using differential gene expression,mutation,and survival analysis.Western blot and Immunohistochemistry were used to analyze MARS1 expression in the liver tissues of patients with HCC.Functional studies,including CCK-8 cell viability assay,EdU cell proliferation assay,cell cycle assays,Transwell migration and invasion assays,and in vivo tumor xenograft models,were conducted to comprehensively elucidate the specific role of MARS1 in HCC.Moreover,the MARS1-related prognostic score(MRPS)was established by LASSO regression and Cox regression analysis in The Cancer Genome Atlas-HCC and GSE14520 cohorts.Patients’immunotherapy and chemotherapy responses were predicted by immunomicroenvironment and drug susceptibility analysis in both subgroups.RESULTS MARS1 was selected as a target gene from a series of ARSs genes,with markedly higher expression observed in HCC tissues compared to adjacent non-cancerous tissues.Silencing MARS1 considerably impeded the proliferation,migration,invasion,and tumorigenic abilities of HCC cells in vitro and in vivo.Moreover,high MRPSs were associated with poor overall survival,altered infiltration of T cells,macrophages,monocytes,elevated immune checkpoint expression(PD-L1,CTLA4,LAG3),and reduced drug sensitivity in HCC.CONCLUSION MARS1 promotes HCC development and represents a potential therapeutic target for HCC management.Furthermore,MRPS serves as an independent prognostic factor for survival and a predictor of tumor treatment response.
文摘BACKGROUND Ferroptosis is a newly recognized form of regulated cell death characterized by iron-dependent accumulation of lipid reactive oxygen species.It has been extensively studied in various diseases,including cancer,Parkinson’s disease,and stroke.However,its precise role and underlying mechanisms in ischemia/reperfusion injury,particularly in the intestinal ischemia-reperfusion(IIR),remain unclear.In current work,we aimed to investigate the participation of histone lactylation during IIR progression.AIM To investigate the role of mitochondrial alanyl-tRNA synthetase 2(AARS2)in ferroptosis and its epigenetic regulation of acyl-CoA synthetase long-chain family member 4(ACSL4)through histone lactylation during IIR injury.METHODS We established a mouse model to mimic IIR and conducted AARS2 knockdown as treatment.The expression of AARS2 in intestinal tissues was measured by western blot.The integrity of intestinal tissues was detected by hematoxylin and eosin staining,serum fatty acid-binding protein,protein levels of ZO-1 and occluding.An in vitro hypoxia-reperfusion(H/R)cell model was established,and cell viability was measured by CCK-8.The in vitro and in vivo ferroptosis was determined by the accumulation of Fe2+and malondialdehyde(MDA).The epigenetic regulation of ACSL4 by AARS2 was detected by chromatin immunoprecipitation(ChIP)assay and luciferase reporter assay.RESULTS We observed a notable elevated AARS2 level in intestinal tissue of mice in IIR model group,which was reversed by shAARS2 treatment.Knockdown of AARS2 repressed alleviated intestinal barrier disruption and repressed the accumulation of ferroptosis biomarker Fe2+and MDA during IIR.The in vitro results showed that shAARS2 alleviated impaired cell viability caused by H/R,as well as repressed ferroptosis.Knockdown of AARS2 notably downregulated the RNA and protein expression of ACSL4.Mechanistically,knockdown of AARS2 downregulated the enrichment of H3K18 La modification on AARS2,as well as suppressed its promoter activity.Overexpression of AARS2 could abolish the protective effects of shACSL4 in vitro.CONCLUSION The elevation of AARS2 during IIR led to cell ferroptosis via epigenetically upregulating the expression of ACSL4.Our findings presented AARS2 as a promising therapeutic target for IIR.
基金supported by grants from the National Natural Science Foundation of China(81973551,82204737,82204686)the Science and Technology Commission of Shanghai Municipality(19ZR1451800,21ZR1460400,and 21140905300)+4 种基金Guoyiqiangyou foundation of Shanghai Hongkou(HGY-KY-2018-03 and HGYMGB-2018-01-05)the Health Commission of Shanghai Municipality(ZY(2021-2023)-0203-04)Shanghai Natural Science Foundation(22ZR1455900)Future Plan for Traditional Chinese Medicine Inheritance and Development of Shanghai Municipal Hospital of TraditionalChineseMedicine(WLJH2021ZY-ZYY007,WL-HBBD-2021001K)Shanghai Putuo District Health System Special Disease Construction Project(2023tszb01).
文摘Black rice,as a dietary supplement,has received increasing attention because of its beneficial health properties.Although black rice and its major ingredients have been considered a potential therapy for ulcerative colitis(UC),its effect and underlying mechanism of action remain obscure.In this study,black rice was demonstrated to improve dextran sulfate sodium salt(DSS)-induced UC and restore intestinal barrier dysfunction.Cyanidin 3-O-glucoside(C3G)is the most abundant ingredient in black rice.Similarly,in vivo and in vitro studies have demonstrated that C3G alleviates colitis and intestinal barrier dysfunction.Proteomic analysis showed that C3G significantly reduced abnormallyelevated swiprosin-1 levels in mice with colitis.Furthermore,the effect of C3G on mitigating colitis was inhibited after swiprosin-1 was overexpressed in intestinal tissue in vivo and Caco-2 cells in vitro.Acyl-CoA synthetase long-chain family member 1(ACSL1)was identified as a potential protein that interacts with swiprosin-1 byco-immunoprecipitation and liquid chromatography-tandem mass spectrometry.By integratingmetabolomics experiments and bioinformatics analysis of single-cell sequencing,ACSL1 was found to selectively bind to swiprosin-1 and regulate downstream linoleic acid metabolism in colitis.Moreover,C3G was observed to prevent the localization of ACSL1 within mitochondria via swiprosin-1,thereby inhibiting the oxidation of linoleic acid.This study demonstrated that C3G targeted swiprosin-1 to ameliorate UC via ASCLl-mediated linoleic acid metabolism,thereby providing a novel potential insight into the mechanism of C3G protection against colitis and establishing the groundwork for its clinical application.
文摘In rice (Oryza sativa L.) roots two glutamine synthetase (GS) isozymes, GSra and GSrb, were identified recently in the author's experiments, but the homology of both GSra and GSrb as well as their localization in the rice roots are unclear. In the present study, the purified GSra and GSrb from rice roots were used to immunize rabbits to obtain the respective antibodies. The immunodiffusion and immunoblotting experiments showed that the antibody against GSra or GSrb was specific for GS and its isozymes. The immunoprecipitation test indicated that the antibody of GSra or GSrb not only recognized its respective antigen, but also well recognized each other's antigen. GSra or GSrb antibody recognized also better cytosolic GS1 of rice leaves, but the recognization for chloroplast GS2 from rice or spinach (Spinacia oleracea Mill.) leaves was weaker. Our results indicate that GSra and GSrb from rice roots are quite similar in antigenicity and are extremely similar proteins and that both GSra and GSrb may also be a form of cytosolic GS just as the cytosolic GS1 of rice leaves.
文摘[Objective] The mRNA expression level changes of S-adenosylmethionine synthetase （SAMS） under low temperature stress was studied. [Method] Total RNA were extracted from leaves, stem and earthnut of sweet potato 0,12,24,48 and 72 h after low temperature treatement, mRNA expression level was analyzed by reverse expression and Real-time PCR technique. [Result] The expression quality of the gene extracted from leaves, stem and earthnut increased and the expression quality reached the peak point 24,72 and 72 h after low temperature treatment respectively. The expression change of earthnut was the biggest. [Conclusion] Low temperature was good for increasing mRNA expression of relevart genes.
基金supported by the National Special Program for Research and Industrialization of Transgenic Plants,China(J2002-B-008)
文摘The regeneration ability of four alfalfa （Medicago sativa L.） cultivars, Xinjiang Daye, Longdong, Gannong 1 and Gannong 3, was studied, and the effects of various cultivars, explant sources and medium recipes on regeneration were compared. The better callus forming frequency obtained from hypocotyls of Xinjiang Daye is 88.5% and regeneration frequency is 9.8% in our initial experiments. To further optimize regeneration system for genetic transformation, we therefore changed concentrations of plant growth regulators and supplemented with glutamine into callus-induction and shoot-regeneration media. Callus forming frequency and shoot differentiation frequency were increased to 100%. The time taken to generate transgenic plants （16 weeks） was shorter than that for previouse procedure （25 weeks） and regeneration frequency was promoted to 15.1%. The results show that addition of glutamine is particularly important for shortening period of regeneration and promoting regeneration frequency. For study of genetic transformation of alfalfa, Agrobacterium tumefaciens-mediated transformation of Xinjiang Daye was developed based on this optimized regeneration system. The plant expression vector carrying two glutamine synthetases （GS 1 and GS2） and △1-pyrroline-5-carboxylate synthetase （P5CS） gene was used for alfalfa in vitro transformation. Six transgenic alfalfa plantlets with resistance to PPT were obtained. The introduction of foreign genes into plants was assessed in the transformants by PCR analysis and Southern hybridizations.
基金supported by funding from the National Key R&D Program of China (2021YFC2301900 and 2301904)National Natural Science Foundation of China (81930062)+2 种基金Science and Technology Department of Jilin Province (YDZJ202201ZYTS590)Health Commission of Jilin Province (2020J059)the Key Laboratory of Molecular Virology,Jilin Province (20102209)
文摘Enterovirus 71(EV71) caused hand, foot and mouth disease(HFMD) is a serious threat to the health of young children. Although type I interferon(IFN-I) has been proven to control EV71 replication, the key downstream IFNstimulated gene(ISG) remains to be clarified and investigated. Recently, we found that 2’-5’-oligoadenylate synthetases 3(OAS3), as one of ISG of IFN-β1b, was antagonized by EV71 3C protein. Here, we confirm that OAS3is the major determinant of IFN-β1b-mediated EV71 inhibition, which depends on the downstream constitutive RNase L activation. 2’-5’-oligoadenylate(2-5A) synthesis activity deficient mutations of OAS3 D816A, D818A,D888A, and K950A lost resistance to EV71 because they could not activate downstream RNase L. Further investigation proved that EV71 infection induced OAS3 but not RNase L expression by IFN pathway. Mechanically, EV71 or IFN-β1b-induced phosphorylation of STAT1, but not STAT3, initiated the transcription of OAS3 by directly binding to the OAS3 promoter. Our works elucidate the immune regulatory mechanism of the host OAS3/RNase L system against EV71 replication.
基金Supported by National Natural Science Foundation of China,No.81373465
文摘Long-chain acyl-Co A synthetase(ACSL) family members include five different ACSL isoforms, each encoded by a separate gene and have multiple spliced variants. ACSLs on endoplasmic reticulum and mitochondrial outer membrance catalyze fatty acids with chain lengths from 12 to 20 carbon atoms to form acyl-Co As, which are lipid metabolic intermediates and involved in fatty acid metabolism, membrane modifications and various physiological processes. Gain- or lossof-function studies have shown that the expression of individual ACSL isoforms can alter the distribution and amount of intracellular fatty acids. Changes in the types and amounts of fatty acids, in turn, can alter the expression of intracellular ACSLs. ACSL family members affect not only the proliferation of normal cells, but the proliferation of malignant tumor cells. They also regulate cell apoptosis through different signaling pathways and molecular mechanisms. ACSL members have individual functions in fatty acid metabolism in different types of cells depending on substrate preferences, subcellular location and tissue specificity, thus contributing to liver diseases and metabolic diseases, such as fatty liver disease, obesity, atherosclerosis and diabetes. They are also linked to neurological disorders and other diseases. However, the mechanisms are unclear. This review addresses new findings in the classification and properties of ACSLs and the fatty acid metabolismassociated effects of ACSLs in diseases.
基金Supported by National Natural Science Foundation Project, No.30971579the Capital Medical Development Foundation, No.2007-2029
文摘AIM:To evaluate effects of UDP-glucuronosyltransferase1A1(UGT1A1) and thymidylate synthetase(TS) gene polymorphisms on irinotecan in metastatic colorectal cancer(mCRC).METHODS:Two irinotecan-and fluorouracil-based regimens,FOLFIRI and IFL,were selected as second-line therapy for 138 Chinese mCRC patients.Genomic DNA was extracted from peripheral blood samples before treatment.UGT1A1 and TS gene polymorphisms were determined by direct sequencing and restriction fragment length polymorphism,respectively.Gene polymorphisms of UGT1A1*28,UGT1A1*6 and promoter enhancer region of TS were analyzed.The relationship between genetic polymorphisms and clinical outcome,that is,response,toxicity and survival were assessed.Pharmacokinetic analyses were performed in a subgroup patients based on different UGT1A1 genotypes.Plasma concentration of irinotecan and its active metabolite SN-38 and inactive metabolite SN-38G were determined by high performance liquid chromatography.Differences in irinotecan and its metabolites between UGT1A1 gene variants were compared.RESULTS:One hundred and eight patients received the FOLFIRI regimen,29 the IFL regimen,and one irinotecan monotherapy.One hundred and thirty patients were eligible for toxicity and 111 for efficacy evaluation.One hundred and thirty-six patients were tested for UGT1A1*28 and *6 genotypes and 125 for promoter enhancer region of TS.Patients showed a higher frequency of wild-type UGT1A1*28(TA6/6) compared with a Caucasian population(69.9% vs 45.2%).No significant difference was found between response rates and UGT1A1 genotype,although wild-type showed lower response rates compared with other variants(17.9% vs 24.2% for UGT1A1*28,15.7% vs 26.8% for UGT1A1*6).When TS was considered,the subgroup with homozygous UGT1A1*28(TA7/7) and non-3RG genotypes showed the highest response rate(33.3%),while wild-type UGT1A1*28(TA6/6) with non-3RG only had a 13.6% response rate,but no significant difference was found.Logistic regression showed treatment duration was closely linked to clinical response.In toxicity comparison,UGT1A1*28 TA6/6 was associated with lower incidence of grade 2-4 diarrhea(27.8% vs 100%),and significantly reduced the risk of grade 4 neutropenia compared with TA7/7(7.8% vs 37.5%).Wild-type UGT1A1*6(G/G) tended to have a lower incidence of grade 3/4 diarrhea vs homozygous mutant(A/A) genotype(13.0% vs 40.0%).Taking UGT1A1 and TS genotypes together,lower incidence of grade 2-4 diarrhea was found in patients with non-3RG TS genotypes,when TA6/6 was compared with TA7/7(35.3% vs 100.0%).No significant association with time to progression(TTP) and overall survival(OS) was observed with either UGT1A1 or TS gene polymorphisms,although slightly longer TTP and OS were found with UGT1A1*28(TA6/6).Irinotecan PK was investigated in 34 patients,which showed high area under concentration curve(AUC) of irinotecan and SN-38,but low AUC ratio(SN-38G /SN-38) in those patients with UGT1A1*28 TA7/7.CONCLUSION:A distinct distribution pattern of UGT1A1 genotypes in Chinese patients might contribute to relatively low toxicity associated with irinotecan and 5-fluorouracil in mCRC patients.
基金the National Natural Science Foundation of China (Nos.30390082 and 40471074).
文摘Real-time polymerase chain reaction analysis was used to compare the effect of NO3^- on the activities of nitrate reductase （NR） and glutamine synthetase （GS）, and the transcript levels of two NR genes, OsNial and OsNia2, two cytosolic GS1 genes, OsGln1;1 and OsGln1;2, and one plastid GS2 gene OsGln2, in two rice （Oryza sativa L.） cultivars Nanguang （NG） and Yunjing （Y J）. Both cultivars achieved greater biomass and higher total N concentration when grown in a mixed N supply than in sole NH4^＋ nutrition. Supply of NO3^- increased NR activity in both leaves and roots. Expression of both NR genes was also substantially enhanced and transcript levels of OsNia2 were significantly higher than those of OsNial. NO3 also caused an increase in GS activity, but had a complex effect on the expression of the three GS genes. In roots, the OsGln1;1 transcript increased, but OsGln1;2 decreased. In leaves, NO3^- had no effect on the GS1 expression, but the transcript for OsGln2 increased both in the leaves and roots of rice with a mixed supply of N. These results suggested that the increase in GS activity might be a result of the complicated regulation of the various GS genes. In addition, the NO3-induced increase of biomass, NR activity, GS activity, and the transcript levels of NR and GS genes were proportionally higher in NG than in Y J, indicating a stronger response of NG to NO3^- nutrition than YJ.
基金Financial supports by the National Natural Science Foun-dation of China (30070431)the Key Technologies R&D Program of China during the 9th Five-Year Plan period(95-Agric-18-04)+1 种基金the Doctoral Fund of Ministry of Edu-cation of China (200805041061)the Earmarked Fund for Modern Agro-Industry Technology Research System, China
文摘The objective is to study whether the accumulation and utilization of plant N are controlled by Mo status in winter wheat cultivars. Mo-efficient cultivar 97003 （eft） and Mo-inefficient cultivar 97014 （ineff） were grown in severely Mo-deficient acidic soil （Tamm-reagent-extractable Mo 0.112 mg kg^-1） with （＋Mo） and without （-Mo） the application of 0.13 mg kg^-1 Mo. The accumulation and use efficiency of plant total N were significantly higher in ＋Mo than that in -Mo and in eft than that in ineff under Mo deficiency. N use efficiency was remarkably higher in maturity but it was forwarded to jointing stage after Mo supply, thus indicating that Mo supply promoted the N use efficiency besides N uptake and eff was efficient in N uptake and utilization. The overall activity of nitrate reductase （NR, EC 1.6.6.1） was significantly higher in ＋Mo than in -Mo and ratio of ＋Mo/-Mo was even to 14.8 at filleting stage for ineff. Activity of glutamine synthetase （GS, EC 6.3.1.2） was significantly lower in ＋Mo than in -Mo. Concentration of nitrate and glutamate were also significantly lower in ＋Mo than in -Mo, thus provided evidences for enhancing N use efficiency by Mo supply. Activities of NR and GS were significantly higher and concentrations of nitrate and glutamate were significantly lower in eff than ineff under Mo deficiency, thus indicated eff was more efficient in N reduction and utilization. It is therefore concluded that Mo could promote N accumulation and utilization in winter wheat which was directly related to NR and feedback regulated by GS. Higher Mo status also results in higher accumulation and utilization of plant N in eft.
