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
BACKGROUND Hepatic ischemia-reperfusion injury(IRI)poses a great challenge in liver surgery and transplantation because of oxidative stress and inflammatory responses.The changes in glutamine synthetase(GS)expression ...BACKGROUND Hepatic ischemia-reperfusion injury(IRI)poses a great challenge in liver surgery and transplantation because of oxidative stress and inflammatory responses.The changes in glutamine synthetase(GS)expression during hepatic IRI remain unclear.AIM To investigate the dynamic expression of GS during hepatic IRI.METHODS Following hepatic ischemia for 1 h and reperfusion,liver tissue samples were collected at 0.5,6,and 24 hours postreperfusion for fixation,embedding,section-ing.Hematoxylin and eosin staining and GS staining were performed.RESULTS GS expression rapidly decreases in hepatocytes around the central vein after IRI,reaching its lowest point at 6 hours postreperfusion,and then gradually recovers.CONCLUSION GS is highly sensitive to IRI,highlighting its potential role as an indicator of liver injury states and a target for therapeutic intervention.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
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
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
BACKGROUND:Hepatocellular carcinoma(HCC)is a highly malignant tumor with a poor prognosis.Because small HCCs possess most of the characteristics of early HCC,we investigated small HCCs to screen potential biomarkers f...BACKGROUND:Hepatocellular carcinoma(HCC)is a highly malignant tumor with a poor prognosis.Because small HCCs possess most of the characteristics of early HCC,we investigated small HCCs to screen potential biomarkers for early diagnosis.METHODS:Proteins were extracted from 10 sets of paired tissue samples from HBV-infected small-HCC patients.The extracted proteins were well resolved by two-dimensional electrophoresis.These HCC-associated proteins were then identified by MALDI-TOF/TOF MS following image analysis.Western blotting and immunohistochemistry were used to assess glutamine synthetase(GS)and phenazine biosynthesislike domain-containing protein(PBLD)expression in liver tissue.Enzyme-linked immunosorbent assays in 152 serum samples(from 49 healthy donors,24 patients with liver cirrhosis,and 79 with HCC)were used to further assess the significance of GS clinically.RESULTS:Fifteen up-regulated and three down-regulated proteins were identified.Western blotting confirmed GS overexpression and decreased PBLD expression in liver tissue.Immunohistochemistry showed that GS was expressed in 70.0%(84/120)of HCCs and 35.8%(43/120)of nontumor tissues;PBLD was expressed in 74.2%(89/120) of nontumor tissues and 40.8%(49/120)of HCCs.The Chi-square test showed significant expression differences between HCCs and adjacent tissues.Consistent with this,serum GS levels in HCC patients were significantly higher than those in liver cirrhosis patients and healthy donors,while the latter two groups were also significantly different.In addition, a diagnostic cutoff value of 2.6 mg/ml was used for GS;it was elevated in 19(76.0%)of 25 HCC patients with AFP≤20 ng/ml and 47(88.7%)of 53 HCC patients with AFP≤200 ng/ml.CONCLUSION:GS and PBLD are abnormally expressed in most HCCs.GS may be a novel serum marker for early HCC, especially for those patients with low AFP levels(≤200 ng/ml).展开更多
Carbamoyl phosphate synthetase i （CPS1） deficiency （CPS1D） is an inborn error of the urea cycle having autosomal （2q34） recessive inheritance that can cause hyperammonemia and neonatal death or mental retardatio...Carbamoyl phosphate synthetase i （CPS1） deficiency （CPS1D） is an inborn error of the urea cycle having autosomal （2q34） recessive inheritance that can cause hyperammonemia and neonatal death or mental retardation. We analyzed the effects on CPS1 activity, kinetic parameters and enzyme stability of missense mutations reported in patients with CPS1 deficiency that map in the 20-kDa C-terminal domain of the enzyme. This domain turns on or off the enzyme depending on whether the essential allosteric activator of CPS 1, N-acetyl- L-glutamate （NAG）, is bound or is not bound to it. To carry out the present studies, we exploited a novel system that allows the expression in vitro and the purification of human CPS1, thus permitting site-directed mutagenesis. These studies have clarified disease causation by individual mutations, identifying functionally important residues, and revealing that a number of mutations decrease the affinity of the enzyme for NAG. Patients with NAG affinity-decreasing mutations might benefit from NAG site saturation therapy with N-carbamyl-L- glutamate （a registered drug, the analog of NAG）. Our results, together with additional present and prior site-directed mutagenesis data for other residues mapping in this domain, suggest an NAG-triggered conformational change in the 134-~4 loop of the C-terminal domain of this enzyme. This change might be an early event in the NAG activation process. Molecular dynamics simulations that were restrained according to the observed effects of the mutations are consistent with this hypothesis, providing further backing for this structurally plausible signaling mechanism by which NAG could trigger urea cycle activation via CPS1.展开更多
Interstitial lung and liver disease(ILLD) is caused by biallelic mutations in the methionyl-tRNA synthetase(MARS) gene. To date, no genetic changes other than missense variants were reported in the literature. Here, w...Interstitial lung and liver disease(ILLD) is caused by biallelic mutations in the methionyl-tRNA synthetase(MARS) gene. To date, no genetic changes other than missense variants were reported in the literature. Here, we report a five-month old female infant with typical ILLD(failure to thrive, developmental delay, jaundice, diffuse interstitial lung disease, hepatomegaly with severe steatosis, anemia, and thrombocytosis) showing novel phenotypes such as kidney stones, acetabular dysplasia, prolonged fever, and extreme leukocytosis. Whole exome sequencing revealed a novel truncating variant(c.2158 C>T/p.Gln720 Stop) together with a novel tri-nucleotide insertion(c.893_894 insTCG that caused the insertion of an arginine at amino acid position 299) in the MARS gene.展开更多
Four japonica rice varieties differed in cooking and eating qualities were used in a pot experiment to study the relationship between the activities of glutamine synthetase during grain filling and rice quality. The a...Four japonica rice varieties differed in cooking and eating qualities were used in a pot experiment to study the relationship between the activities of glutamine synthetase during grain filling and rice quality. The activities of glutamine synthetase gradually increased and then declined as a single peak curve in the course of grain filling. The 15th day after heading was a turning point, before which the enzymatic activities in the inferior rice varieties with high protein content were higher than those in the superior rice varietie with low protein content, and after which it was converse. The activity of glutamine synthetase in grain was correlated with the taste meter value, peak viscosity and breakdown negatively at the early stage of grain filling whereas positively at the middle and late stages. Moreover, it was correlated with the protein content of rice grain and setback positively at the early stage and negatively at the middle and late stages. The correlation degree varied with the course of grain filling. From 15 days to 20 days after heading was a critical stage, in which the direction of correlation between the activity of glutamine synthetase and taste meter value and RVA properties of rice changed.展开更多
IM To establish a nonradioactive assay for 2′5′ oligoadenylate synthetase (25 AS) and to measure the 25AS in peripheral blood mononuclear cell (PBMC) extracts of patients with chronic hepatitis C before IFNα injec...IM To establish a nonradioactive assay for 2′5′ oligoadenylate synthetase (25 AS) and to measure the 25AS in peripheral blood mononuclear cell (PBMC) extracts of patients with chronic hepatitis C before IFNα injection, 24 hours and one month after the first injection.METHODS 25AS in cell extracts of PBMCs from 10 normal persons and 15 chronic hepatitis C patients were determined with PEI cellulose thinlayer chromatography.RESULTS The assay of 25AS in human PBMC was found to be rapid, sensitive, specific and reliable. The 25AS activity of PBMC in normal persons was in a quite low level (20%), and it was increased about tenfolds after stimulation of IFN (197%), (P<001). In 15 chronic hepatitic C patients, the basal levels of 25AS before IFN treatment were higher than those of normal persons, being much higher in the group showing poor response to IFN treatment, but 24h after the first injection of IFNα the 25AS level showed a more rapid and much greater rise in those patients with a good response.CONCLUSION 25AS may be a useful parameter of biological response during the IFN therapy..展开更多
AIM： To investigate the association of the inducible ni- tric oxide synthetase （iNOS） C150T polymorphism with Helicobacter pylori （H. pylor/） infection and gastric can- cer （GC） risk in Iran. METHODS： In order...AIM： To investigate the association of the inducible ni- tric oxide synthetase （iNOS） C150T polymorphism with Helicobacter pylori （H. pylor/） infection and gastric can- cer （GC） risk in Iran. METHODS： In order to determine whether there was a correlation between iNOS genotype and GC in Iran, we conducted a case-control study using samples from 329 individuals. For each sample, the C150T ilVOS poly- morphism was genotyped by polymerase chain reaction （PCR） and restriction digestion. Patients were grouped by cancer presence, demographic and behavior charac- teristics, and/-/, pylori infection status. Statistical tests were conducted to determine whether any behavioral factors or a particular iNOS genotype was associated with GC in the study population. RESULTS： In this population, we found that smok- ing, hot beverage consumption, a familial history of GC and H. pylori infection status were significantly associated with GC development （P = 0.015, P 〈 0.001, P = 0.0034, and P 〈 0.015, respectively）. The distribution of the C150T ilVOS genotypes among the two study groups was not statistically significant alone, but was impacted by H. pylori infection status. When compared to the non-/-/, pylori infected group, cancer patients who had a heterozygous CT genotype and were also infected with H. pylori were 2.1 times more at risk of developing GC [odds ratio （OR） = 2.1, P = 0.03] while those with a homozygous TT genotype and infected with H. pylori were 5.0 times more at risk of developing GC （OR = 5.0, P = 0.029）. In contrast, this association was not seen in patients in the control group.CONCLUSION： ACT or TT polymorphism at position 150 in the iNO$ gene significantly increases the risk of GC and may be a marker for GC susceptibility.展开更多
The intestinal mucosa is characterized by a high complexity in terms of structure and functions and allows for a controlled demarcation towards the gut lumen.On the one hand it is responsible for pulping and selective...The intestinal mucosa is characterized by a high complexity in terms of structure and functions and allows for a controlled demarcation towards the gut lumen.On the one hand it is responsible for pulping and selective absorption of alimentary substances ensuring the immunological tolerance,on the other hand it prevents the penetration of micro-organisms as well as bacterial outgrowth.The continuous regeneration of surface epithelia along the crypt-villus-axis in the small intestine is crucial to assuring these various functions.The core phenomena of intestinal epithelia regeneration comprise cell proliferation,migration,differentiation,and apoptosis.These partly contrarily oriented processes are molecularly balanced through numerous interacting signaling pathways like Wnt/β-catenin,Notch and Hedgehog,and regulated by various modifying factors.One of these modifiers is acyl-CoA synthetase 5(ACSL5).It plays a key role in de novo lipid synthesis,fatty acid degradation and membrane modifications,and regulates several intestinal processes,primarily through different variants of protein lipidation,e.g.,palmitoylation.ACSL5 was shown to interact with proapoptotic molecules,and besides seems to inhibit proliferation along the crypt-villus-axis.Because of its proapoptotic and antiproliferative characteristics it could be of significant relevance for intestinal homeostasis,cellular disorder and tumor development.展开更多
Plant glutamine synthetase(GS,EC6.3.1.2)catalyzes the synthesis of glutamine from glutamate and ammonium ions and acts as a key enzyme in the nitrogen metabolic pathway in organisms.Nitrogen is an essential element fo...Plant glutamine synthetase(GS,EC6.3.1.2)catalyzes the synthesis of glutamine from glutamate and ammonium ions and acts as a key enzyme in the nitrogen metabolic pathway in organisms.Nitrogen is an essential element for plant growth and development and plays an important role in crop yield and quality formation.Therefore,GS is crucial in many physiological processes in plants.Currently,nitrogen regulation by GS in plants is well-studied in terms of its effect on plant growth and development.This article reviews the regulatory role of plant GS and its molecular mechanism in mitigating stress injury,such as low or high temperature,salinity,drought and oxidation.The function of plant GS in stress tolerance response is focused.The review aims to provide a reference for the utilization of plant GS in crop stress tolerance breeding.展开更多
Nitrogen is a key element to control the growth and yield of crops. Fertilizer urea nitrogen (N) 60,45, and 30 kg/hm2 was applied at three different stages, midtillering, panicle initiation, and flowering, of the grow...Nitrogen is a key element to control the growth and yield of crops. Fertilizer urea nitrogen (N) 60,45, and 30 kg/hm2 was applied at three different stages, midtillering, panicle initiation, and flowering, of the growth and development of rice plants, respectively. At both midtillering and panicle initiation, the total activity of glutamine synthetase (GS) in rice roots and leaves was incrased remarkably as a result of a large amount of ammonia absorbed by roots. Native-PAGE and activity staining showed that the increase of total activity in rice roots and leaves was due to the synthesis of GSrb in roots and GS2 in leaves and that the activity of GSra in roots and GS1 in leaves remained constant. The results showed that the assimilation of external nitrogen was carried out by GSrb but not GSra in rice roots and that the activitry of GS2 was induced also by the external nitrogen, and that GSrb played main role in meeting the needs of the rapid tillering for nitrogen. At flowering, the activity of GS in rice roots and leaves did not change almost after topdressing. These rssults suggest that the change of GS activity in rice roots may use as a measure of the utilization efficiency of the fertilizer.展开更多
Long-chain acyl coenzyme A synthetase(ACSL) is a member of the synthetase family encoded by a multigene family;it plays an important role in the absorption and transport of fatty acid.Here we review the roles of ACSL ...Long-chain acyl coenzyme A synthetase(ACSL) is a member of the synthetase family encoded by a multigene family;it plays an important role in the absorption and transport of fatty acid.Here we review the roles of ACSL in the regulating absorption and transport of fatty acid,as well as the connection between ACSL and some metabolic diseases.展开更多
Asparagine is an efficient nitrogen transport and storage carrier. Asparagine synthesis occurs by the amination of aspartate which is catalyzed by asparagine synthetase(ASN) in plants. Complete genome-wide analysis an...Asparagine is an efficient nitrogen transport and storage carrier. Asparagine synthesis occurs by the amination of aspartate which is catalyzed by asparagine synthetase(ASN) in plants. Complete genome-wide analysis and classifications of the ASN gene family have recently been reported in different plants. However, systematic analysis and expression profiles of these genes have not been performed in apple(Malus domestica). Here, a comprehensive bioinformatics approach was applied to identify MdASNs in apple. Then, plant phylogenetic tree, chromosome location, conserved protein motif, gene structure, and expression pattern of MdASNs were analyzed. Five members were identified and distributed on 4 chromosomes with conserved GATase-7 and ASN domains. Expression analysis indicated that all MdASNs mRNA accumulated at the highest level in reproductive organs, namely flowers or fruits, which may be associated with the redistribution of free amino acids in plant metabolic organs and reservoirs. Additionally, most of Md ASNs were dramatically up-regulated under various nitrogen supplies, especially in the aboveground part. Taken together, MdASNs may be assigned to be responsible for the nitrogen metabolism and asparagine synthesis in apple.展开更多
Phosphoribosyl-pyrophosphate synthetase 2(PRPS2)is a rate-limiting enzyme and plays an important role in purine and pyrimidine nucleotide synthesis.Recent studies report that PRPS2 is involved in male infertility.Howe...Phosphoribosyl-pyrophosphate synthetase 2(PRPS2)is a rate-limiting enzyme and plays an important role in purine and pyrimidine nucleotide synthesis.Recent studies report that PRPS2 is involved in male infertility.However,the role of PRPS2 in hypospermatogenesis is unknown.In this study,the relationship of PRPS2 with hypospermatogenesis and spermatogenic cell apoptosis was investigated.The results showed that PRPS2 depletion increased the number of apoptotic spermatogenic cells in vitro.PRPS2 was downregulated in a mouse model of hypospermatogenesis.When PRPS2 expression was knocked down in mouse testes,hypospermatogenesis and accelerated apoptosis of spermatogenic cells were noted.E2F transcription factor 1(E2F1)was confirmed as the target gene of PRPS2 and played a key role in cell apoptosis by regulating the P53/Bcl-xl/Bcl-2/Caspase 6/Caspase 9 apoptosis pathway.Therefore,these data indicate that PRPS2 depletion contributes to the apoptosis of spermatogenic cells and is associated with hypospermatogenesis,which may be helpful for the diagnosis of male infertility.展开更多
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.
文摘BACKGROUND Hepatic ischemia-reperfusion injury(IRI)poses a great challenge in liver surgery and transplantation because of oxidative stress and inflammatory responses.The changes in glutamine synthetase(GS)expression during hepatic IRI remain unclear.AIM To investigate the dynamic expression of GS during hepatic IRI.METHODS Following hepatic ischemia for 1 h and reperfusion,liver tissue samples were collected at 0.5,6,and 24 hours postreperfusion for fixation,embedding,section-ing.Hematoxylin and eosin staining and GS staining were performed.RESULTS GS expression rapidly decreases in hepatocytes around the central vein after IRI,reaching its lowest point at 6 hours postreperfusion,and then gradually recovers.CONCLUSION GS is highly sensitive to IRI,highlighting its potential role as an indicator of liver injury states and a target for therapeutic intervention.
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 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.
基金supported by a grant from the Beijing Municipal Science and Technology Commission(No.Z0006264040791)
文摘BACKGROUND:Hepatocellular carcinoma(HCC)is a highly malignant tumor with a poor prognosis.Because small HCCs possess most of the characteristics of early HCC,we investigated small HCCs to screen potential biomarkers for early diagnosis.METHODS:Proteins were extracted from 10 sets of paired tissue samples from HBV-infected small-HCC patients.The extracted proteins were well resolved by two-dimensional electrophoresis.These HCC-associated proteins were then identified by MALDI-TOF/TOF MS following image analysis.Western blotting and immunohistochemistry were used to assess glutamine synthetase(GS)and phenazine biosynthesislike domain-containing protein(PBLD)expression in liver tissue.Enzyme-linked immunosorbent assays in 152 serum samples(from 49 healthy donors,24 patients with liver cirrhosis,and 79 with HCC)were used to further assess the significance of GS clinically.RESULTS:Fifteen up-regulated and three down-regulated proteins were identified.Western blotting confirmed GS overexpression and decreased PBLD expression in liver tissue.Immunohistochemistry showed that GS was expressed in 70.0%(84/120)of HCCs and 35.8%(43/120)of nontumor tissues;PBLD was expressed in 74.2%(89/120) of nontumor tissues and 40.8%(49/120)of HCCs.The Chi-square test showed significant expression differences between HCCs and adjacent tissues.Consistent with this,serum GS levels in HCC patients were significantly higher than those in liver cirrhosis patients and healthy donors,while the latter two groups were also significantly different.In addition, a diagnostic cutoff value of 2.6 mg/ml was used for GS;it was elevated in 19(76.0%)of 25 HCC patients with AFP≤20 ng/ml and 47(88.7%)of 53 HCC patients with AFP≤200 ng/ml.CONCLUSION:GS and PBLD are abnormally expressed in most HCCs.GS may be a novel serum marker for early HCC, especially for those patients with low AFP levels(≤200 ng/ml).
基金supported by grants from the Alicia Koplowitz Foundation, the Valencian government (No. Prometeo II/2014/ 029 to V.R.)the Spanish government (Nos. BFU2011-30407 to V.R., BFU2012-30770 to J.G. and a FPU fellowship to C.D.-F.)the Swiss National Science Foundation (No. 310030_127184 to J.H.)
文摘Carbamoyl phosphate synthetase i （CPS1） deficiency （CPS1D） is an inborn error of the urea cycle having autosomal （2q34） recessive inheritance that can cause hyperammonemia and neonatal death or mental retardation. We analyzed the effects on CPS1 activity, kinetic parameters and enzyme stability of missense mutations reported in patients with CPS1 deficiency that map in the 20-kDa C-terminal domain of the enzyme. This domain turns on or off the enzyme depending on whether the essential allosteric activator of CPS 1, N-acetyl- L-glutamate （NAG）, is bound or is not bound to it. To carry out the present studies, we exploited a novel system that allows the expression in vitro and the purification of human CPS1, thus permitting site-directed mutagenesis. These studies have clarified disease causation by individual mutations, identifying functionally important residues, and revealing that a number of mutations decrease the affinity of the enzyme for NAG. Patients with NAG affinity-decreasing mutations might benefit from NAG site saturation therapy with N-carbamyl-L- glutamate （a registered drug, the analog of NAG）. Our results, together with additional present and prior site-directed mutagenesis data for other residues mapping in this domain, suggest an NAG-triggered conformational change in the 134-~4 loop of the C-terminal domain of this enzyme. This change might be an early event in the NAG activation process. Molecular dynamics simulations that were restrained according to the observed effects of the mutations are consistent with this hypothesis, providing further backing for this structurally plausible signaling mechanism by which NAG could trigger urea cycle activation via CPS1.
基金Supported by the National Natural Science Foundation of China,No.81570468
文摘Interstitial lung and liver disease(ILLD) is caused by biallelic mutations in the methionyl-tRNA synthetase(MARS) gene. To date, no genetic changes other than missense variants were reported in the literature. Here, we report a five-month old female infant with typical ILLD(failure to thrive, developmental delay, jaundice, diffuse interstitial lung disease, hepatomegaly with severe steatosis, anemia, and thrombocytosis) showing novel phenotypes such as kidney stones, acetabular dysplasia, prolonged fever, and extreme leukocytosis. Whole exome sequencing revealed a novel truncating variant(c.2158 C>T/p.Gln720 Stop) together with a novel tri-nucleotide insertion(c.893_894 insTCG that caused the insertion of an arginine at amino acid position 299) in the MARS gene.
文摘Four japonica rice varieties differed in cooking and eating qualities were used in a pot experiment to study the relationship between the activities of glutamine synthetase during grain filling and rice quality. The activities of glutamine synthetase gradually increased and then declined as a single peak curve in the course of grain filling. The 15th day after heading was a turning point, before which the enzymatic activities in the inferior rice varieties with high protein content were higher than those in the superior rice varietie with low protein content, and after which it was converse. The activity of glutamine synthetase in grain was correlated with the taste meter value, peak viscosity and breakdown negatively at the early stage of grain filling whereas positively at the middle and late stages. Moreover, it was correlated with the protein content of rice grain and setback positively at the early stage and negatively at the middle and late stages. The correlation degree varied with the course of grain filling. From 15 days to 20 days after heading was a critical stage, in which the direction of correlation between the activity of glutamine synthetase and taste meter value and RVA properties of rice changed.
文摘IM To establish a nonradioactive assay for 2′5′ oligoadenylate synthetase (25 AS) and to measure the 25AS in peripheral blood mononuclear cell (PBMC) extracts of patients with chronic hepatitis C before IFNα injection, 24 hours and one month after the first injection.METHODS 25AS in cell extracts of PBMCs from 10 normal persons and 15 chronic hepatitis C patients were determined with PEI cellulose thinlayer chromatography.RESULTS The assay of 25AS in human PBMC was found to be rapid, sensitive, specific and reliable. The 25AS activity of PBMC in normal persons was in a quite low level (20%), and it was increased about tenfolds after stimulation of IFN (197%), (P<001). In 15 chronic hepatitic C patients, the basal levels of 25AS before IFN treatment were higher than those of normal persons, being much higher in the group showing poor response to IFN treatment, but 24h after the first injection of IFNα the 25AS level showed a more rapid and much greater rise in those patients with a good response.CONCLUSION 25AS may be a useful parameter of biological response during the IFN therapy..
基金Supported by The Mazandaran University of Medical Sciences,No. 88-512
文摘AIM： To investigate the association of the inducible ni- tric oxide synthetase （iNOS） C150T polymorphism with Helicobacter pylori （H. pylor/） infection and gastric can- cer （GC） risk in Iran. METHODS： In order to determine whether there was a correlation between iNOS genotype and GC in Iran, we conducted a case-control study using samples from 329 individuals. For each sample, the C150T ilVOS poly- morphism was genotyped by polymerase chain reaction （PCR） and restriction digestion. Patients were grouped by cancer presence, demographic and behavior charac- teristics, and/-/, pylori infection status. Statistical tests were conducted to determine whether any behavioral factors or a particular iNOS genotype was associated with GC in the study population. RESULTS： In this population, we found that smok- ing, hot beverage consumption, a familial history of GC and H. pylori infection status were significantly associated with GC development （P = 0.015, P 〈 0.001, P = 0.0034, and P 〈 0.015, respectively）. The distribution of the C150T ilVOS genotypes among the two study groups was not statistically significant alone, but was impacted by H. pylori infection status. When compared to the non-/-/, pylori infected group, cancer patients who had a heterozygous CT genotype and were also infected with H. pylori were 2.1 times more at risk of developing GC [odds ratio （OR） = 2.1, P = 0.03] while those with a homozygous TT genotype and infected with H. pylori were 5.0 times more at risk of developing GC （OR = 5.0, P = 0.029）. In contrast, this association was not seen in patients in the control group.CONCLUSION： ACT or TT polymorphism at position 150 in the iNO$ gene significantly increases the risk of GC and may be a marker for GC susceptibility.
文摘The intestinal mucosa is characterized by a high complexity in terms of structure and functions and allows for a controlled demarcation towards the gut lumen.On the one hand it is responsible for pulping and selective absorption of alimentary substances ensuring the immunological tolerance,on the other hand it prevents the penetration of micro-organisms as well as bacterial outgrowth.The continuous regeneration of surface epithelia along the crypt-villus-axis in the small intestine is crucial to assuring these various functions.The core phenomena of intestinal epithelia regeneration comprise cell proliferation,migration,differentiation,and apoptosis.These partly contrarily oriented processes are molecularly balanced through numerous interacting signaling pathways like Wnt/β-catenin,Notch and Hedgehog,and regulated by various modifying factors.One of these modifiers is acyl-CoA synthetase 5(ACSL5).It plays a key role in de novo lipid synthesis,fatty acid degradation and membrane modifications,and regulates several intestinal processes,primarily through different variants of protein lipidation,e.g.,palmitoylation.ACSL5 was shown to interact with proapoptotic molecules,and besides seems to inhibit proliferation along the crypt-villus-axis.Because of its proapoptotic and antiproliferative characteristics it could be of significant relevance for intestinal homeostasis,cellular disorder and tumor development.
基金supported by Qingdao Agriculture University Internal Strategic Research Fund,National Natural Science Foundation of China(32101715)the Foundation of Research and Application of Whole Genome Selection in Wheat(2019LZGC016)+1 种基金the High-Level Talents Project of Qingdao Agricultural University(663/1119057)the State Key Laboratory of Crop Biology at Shandong Agricultural University(2020KF03)。
文摘Plant glutamine synthetase(GS,EC6.3.1.2)catalyzes the synthesis of glutamine from glutamate and ammonium ions and acts as a key enzyme in the nitrogen metabolic pathway in organisms.Nitrogen is an essential element for plant growth and development and plays an important role in crop yield and quality formation.Therefore,GS is crucial in many physiological processes in plants.Currently,nitrogen regulation by GS in plants is well-studied in terms of its effect on plant growth and development.This article reviews the regulatory role of plant GS and its molecular mechanism in mitigating stress injury,such as low or high temperature,salinity,drought and oxidation.The function of plant GS in stress tolerance response is focused.The review aims to provide a reference for the utilization of plant GS in crop stress tolerance breeding.
文摘Nitrogen is a key element to control the growth and yield of crops. Fertilizer urea nitrogen (N) 60,45, and 30 kg/hm2 was applied at three different stages, midtillering, panicle initiation, and flowering, of the growth and development of rice plants, respectively. At both midtillering and panicle initiation, the total activity of glutamine synthetase (GS) in rice roots and leaves was incrased remarkably as a result of a large amount of ammonia absorbed by roots. Native-PAGE and activity staining showed that the increase of total activity in rice roots and leaves was due to the synthesis of GSrb in roots and GS2 in leaves and that the activity of GSra in roots and GS1 in leaves remained constant. The results showed that the assimilation of external nitrogen was carried out by GSrb but not GSra in rice roots and that the activitry of GS2 was induced also by the external nitrogen, and that GSrb played main role in meeting the needs of the rapid tillering for nitrogen. At flowering, the activity of GS in rice roots and leaves did not change almost after topdressing. These rssults suggest that the change of GS activity in rice roots may use as a measure of the utilization efficiency of the fertilizer.
基金Supported by the National Natural Science Foundation of China(81373465)
文摘Long-chain acyl coenzyme A synthetase(ACSL) is a member of the synthetase family encoded by a multigene family;it plays an important role in the absorption and transport of fatty acid.Here we review the roles of ACSL in the regulating absorption and transport of fatty acid,as well as the connection between ACSL and some metabolic diseases.
基金financially supported by the National Natural Science Foundation of China(31901574 and 31570271)。
文摘Asparagine is an efficient nitrogen transport and storage carrier. Asparagine synthesis occurs by the amination of aspartate which is catalyzed by asparagine synthetase(ASN) in plants. Complete genome-wide analysis and classifications of the ASN gene family have recently been reported in different plants. However, systematic analysis and expression profiles of these genes have not been performed in apple(Malus domestica). Here, a comprehensive bioinformatics approach was applied to identify MdASNs in apple. Then, plant phylogenetic tree, chromosome location, conserved protein motif, gene structure, and expression pattern of MdASNs were analyzed. Five members were identified and distributed on 4 chromosomes with conserved GATase-7 and ASN domains. Expression analysis indicated that all MdASNs mRNA accumulated at the highest level in reproductive organs, namely flowers or fruits, which may be associated with the redistribution of free amino acids in plant metabolic organs and reservoirs. Additionally, most of Md ASNs were dramatically up-regulated under various nitrogen supplies, especially in the aboveground part. Taken together, MdASNs may be assigned to be responsible for the nitrogen metabolism and asparagine synthesis in apple.
基金the Science and Technology Projects of Shenzhen(No.JCYJ20160428173152329)the Fundamental Research Funds for the Central Universities(No.21617316)+1 种基金the Guangdong Medical Research Fund(No.A2019553)the National Natural Science Foundation of China(No.81773277).
文摘Phosphoribosyl-pyrophosphate synthetase 2(PRPS2)is a rate-limiting enzyme and plays an important role in purine and pyrimidine nucleotide synthesis.Recent studies report that PRPS2 is involved in male infertility.However,the role of PRPS2 in hypospermatogenesis is unknown.In this study,the relationship of PRPS2 with hypospermatogenesis and spermatogenic cell apoptosis was investigated.The results showed that PRPS2 depletion increased the number of apoptotic spermatogenic cells in vitro.PRPS2 was downregulated in a mouse model of hypospermatogenesis.When PRPS2 expression was knocked down in mouse testes,hypospermatogenesis and accelerated apoptosis of spermatogenic cells were noted.E2F transcription factor 1(E2F1)was confirmed as the target gene of PRPS2 and played a key role in cell apoptosis by regulating the P53/Bcl-xl/Bcl-2/Caspase 6/Caspase 9 apoptosis pathway.Therefore,these data indicate that PRPS2 depletion contributes to the apoptosis of spermatogenic cells and is associated with hypospermatogenesis,which may be helpful for the diagnosis of male infertility.
