Uridine diphosphate glucuronosyltransferase 1A1 prevents the progression of liver injury

BACKGROUND Uridine diphosphate glucuronosyltransferase 1A1(UGT1A1)plays a crucial role in metabolizing and detoxifying endogenous and exogenous substances.However,its contribution to the progression of liver damage remains unclear.AIM To determine the role and mechanism of UGT1A1 in liver damage progression.METHODS We investigated the relationship between UGT1A1 expression and liver injury through clinical research.Additionally,the impact and mechanism of UGT1A1 on the progression of liver injury was analyzed through a mouse model study.RESULTS Patients with UGT1A1 gene mutations showed varying degrees of liver damage,while patients with acute-onchronic liver failure(ACLF)exhibited relatively reduced levels of UGT1A1 protein in the liver as compared to patients with chronic hepatitis.This suggests that low UGT1A1 levels may be associated with the progression of liver damage.In mouse models of liver injury induced by carbon tetrachloride(CCl_(4))and concanavalin A(ConA),the hepatic levels of UGT1A1 protein were found to be increased.In mice with lipopolysaccharide or liver steatosis-mediated liver-injury progression,the hepatic protein levels of UGT1A1 were decreased,which is consistent with the observations in patients with ACLF.UGT1A1 knockout exacerbated CCl_(4)-and ConA-induced liver injury,hepatocyte apoptosis and necroptosis in mice,intensified hepatocyte endoplasmic reticulum(ER)stress and oxidative stress,and disrupted lipid metabolism.CONCLUSION UGT1A1 is upregulated as a compensatory response during liver injury,and interference with this upregulation process may worsen liver injury.UGT1A1 reduces ER stress,oxidative stress,and lipid metabolism disorder,thereby mitigating hepatocyte apoptosis and necroptosis.

Targeting uridine diphosphate glucuronosyltransferase 1A1 in liver disease:Current research and future directions

The current letter to the editor pertains to the manuscript entitled'Uridine diphosphate glucuronosyltransferase 1A1 prevents the progression of liver injury'.Increased levels of uridine diphosphate glucuronosyltransferase 1A1 during liver injury could mitigate damage by reducing endoplasmic reticulum stress,oxidative stress,and dysregulated lipid metabolism,impeding hepatocyte apoptosis and necroptosis.

Protective Effects of Sodium Magnesium Fructose Diphosphate on Brain Damage of Rats Subjected to Focal Cerebral Ischemia and Reperfusion

Objective: To study the effects of sodium magnesiusm fructose diphosphate(FDPM) on brain damage of rats after ischemia-reperfusion. Methods: Rats were subjected to cerebral ischemia-reperfusion induced by inserting a nylon thread into internal carotid artery to block the origin of middle cerebral artery and removing the thread later. FDPM (400 mg·kg -1), fructose-1,6-diphosphate (FDP, 400 mg·kg -1)and magnesium sulfate (MgSO 4, 30 mg·kg -1) were administrated 10 min after the onset of ischemia. Neurological scale, brain infarct area, Malondialdehyde(MDA) content and histopathological changes of brain tissue were studied. Results: FDPM decreased neurological scale, diminished brain infarct area, reduced MDA content and relieved histopathological change of rat brain tissue subjected to ischemia-reperfusion. These effects were more powerful than that of FDP or MgSO 4. Conclusions: It is suggested that FDPM markedly prevented rats against brain damage after cerebral ischemia-reperfusion, and its effect was better than that of FDP or MgSO 4.

No association between cyclooxygenase-2 and uridine diphosphate glucuronosyltransferase 1A6 genetic polymorphisms and colon cancer risk

AIM：To investigate the association of variations in the cyclooxygenase-2 （COX2） and uridine diphosphate glucuronosyltransferase 1A6 （UGTIA6） genes and non-steroidal anti-inflammatory drugs （NSAIDs） use with risk of colon cancer.METHODS： NSAIDs, which are known to reduce the risk of colon cancer, act directly on COX2 and reduce its activity. Epidemiological studies have associated variations in the COX2 gene with colon cancer risk, but others were unable to replicate this finding. Similarly,enzymes in the UGT1A6 gene have been demonstrated to modify the therapeutic effect of NSAIDs on colon adenomas. Polymorphisms in the UGTIA6 gene have been statistically shown to interact with NSAID intake to influence risk of developing colon adenomas, but not colon cancer. Here we examined the association of tagging single nucleotide polymorphisms （SNPs） in the COX2 and UGTIA6 genes, and their interaction with NSAID consumption, on risk of colon cancer in a population of 422 colon cancer cases and 481 population controls.RESULTS： No SNP in either gene was individually statistically significantly associated with colon cancer, nor did they statistically significantly change the protective effect of NSAID consumption in our sample. Like others, we were unable to replicate the association of variants in the COX2 gene with colon cancer risk （P 〉 0.05）,and we did not observe that these variants modify the protective effect of NSAIDs （P 〉 0.05）. We were able to confirm the lack of association of variants in UGT1A6 with colon cancer risk, although further studies will have to be conducted to confirm the association of these variants with colon adenomas.CONCLUSION： Our study does not support a role of COX2 and UGTIA6 genetic variations in the development of colon cancer.

Roles and mechanisms of the CD38/cyclic adenosine diphosphate ribose/Ca^(2+) signaling pathway

Mobilization of intracellular Ca2+ stores is involved inmany diverse cell functions, including: cell proliferation;differentiation; fertilization; muscle contraction; secre-tion of neurotransmitters, hormones and enzymes;and lymphocyte activation and proliferation. Cyclic ad-enosine diphosphate ribose(cADPR) is an endogenousCa2+ mobilizing nucleotide present in many cell typesand species, from plants to animals. cADPR is formedby ADP-ribosyl cyclases from nicotinamide adenine di-nucleotide. The main ADP-ribosyl cyclase in mammalsis CD38, a multi-functional enzyme and a type Ⅱ mem-brane protein. It has been shown that many extracel-lular stimuli can induce cADPR production that leadsto calcium release or influx, establishing cADPR as asecond messenger. cADPR has been linked to a widevariety of cellular processes, but the molecular mecha-nisms regarding cADPR signaling remain elusive. Theaim of this review is to summarize the CD38/cADPR/Ca2+ signaling pathway, focusing on the recent advanc-es involving the mechanism and physiological functionsof cADPR-mediated Ca2+ mobilization.

Decaprenyl diphosphate synthase subunit 2 as a prognosis factor in hepatocellular carcinoma

AIM:To investigate the involvement of decaprenyl diphosphate synthase subunit 2(PDSS2) in development and progression of human hepatocellular carcinoma(HCC).METHODS:PDSS2 protein expression was examined in well-and poorly differentiated HCC tumor samples.The levels of PDSS2 expression were compared with clinical features and prognosis of HCC patients.The effects of PDSS2 on cell proliferation,cell cycle,apoptosis,cell migration,and invasion in HCC Hep G2 cells were also investigated.RESULTS:PDSS2 was downregulated in poorly differentiated cancer samples compared with welldifferentiated tumor samples,and the expression level was markedly lower in HCC tissues than in histologically normal tissue adjacent to the cancer.Reduced protein expression was negatively associated with the status of HCC progression.In addition,overexpression of PDSS2dramatically suppressed cell proliferation and colony formation,and induced apoptosis in Hep G2 cells by inducing G1-phase cell-cycle arrest.The migration and invasion capabilities of Hep G2 cells were significantly decreased following PDSS2 overexpression.CONCLUSION:Decreased PDSS2 expression is an unfavorable prognostic factor for HCC,and PDSS2 has potent anticancer activity in HCC tissues and Hep G2cells.

Heterologous expression of active human undine diphosphate glucuronosyltransferase 1A3 in Chinese hamster lung cells

AIM: To obtain the active human recombinant uridine diphosphate glucuronosyltransferase 1A3 (UGT1A3) enzyme from Chinese hamster lung (CHL) cells.METHODS: The full-length UGT1A3 gene was amplified by reverse transcription-polymerase chain reaction (RT-PCR)using total RNA from human liver as template. The correct fragment confirmed by sequencing was subcloned into the mammalian expression vector pcDNA3.1 (+), and the recombinant vector was transfected into CHL cells using a calcium phosphate method. Expressed UGT1A3 protein was prepared from CHL cells resistant to neomycin (G418). Then the protein was added into a reaction mixture for glucuronidation of quercetin. The glucuronidation activity of UGT1A3 was determined by reverse phase-high performance liquid chromatography (RP-HPLC) coupled with a diode array detector (DAD). The quercetin glucuronide was confirmed by hydrolysis with β-glucuronidase. Control experiments were performed in parallel. The transcriptions of recombinants were also determined by RT-PCR.RESULTS: The gene was confirmed to be an allele (UGT1A3-3) of UGT1A3 by DNA sequencing. The fragment was introduced into pcDNA3.1 (+) successfully. Several colonies were obtained under the selection pressure of G418.The result of RT-PCR showed transcription of recombinants in mRNA level. Glucuronidation assay and HPLC analysis indicated UGT1A3 expressed heterologously in CHL cells was in an active form, and one of the gulcuronides corresponding to quercetin was also detected.CONCLUSION: Correct sequence of UGT1A3 gene can be obtained, and active UGT1A3 enzyme is expressed heterologously in CHL cells.

Expression,Purification,Crystallization and Preliminary Crystallographic Analysis of Nucleoside Diphosphate Kinase(NDK)from Aspergillus Flavus

Aspergillus flavus causes serious disease on important agriculture crops, and its secondary metabolic products-aflatoxins are most potent toxin and carcinogen for animal and human, Structural and functional studies ofA. flavus proteins may provide insights into the identification of potential therapeutic targets and prevention of damage caused by A. flavus. Here, we report the expression, purification, crystallization and preliminary crystallographic analysis of NDK protein from A. flavus. The NDK protein was expressed in E. coli and purified by using a series of chromatographic methods to 〉98% purity. The recombinant protein was crystallized and the crystals diffracted to 2.4 A^° resolution. The crystal of NDK is in space group of C121 with a = 190.84, b = 169.47, c = 146.94 A^°. Preliminary data analysis indicated that the NDK molecule assembles into a multimer in the asymmetric unit.

Electrochemical Studies of Effect of Eu^(3+) on Adenosine-5′-Diphosphate at Mercury Electrode

The electrochemical behavior of the adenosine5diphosphate(ADP) was studied in 005 molL-1 MES buffer solution(pH 585) at mercury electrode. There are no reduction and oxidation waves for the adenosine5diphosphate in the range of -04-14 V(vs. Ag/AgCl). In a mixture solution of Eu3+ and ADP(Eu3+ADP=14), a reduction peak is obtained at -078 V. Comparing with the cyclic voltammograms of Eu3+ ions under the same experimental conditions, it is found that the complex of Eu3+ADP can be produced in above solutions between Eu3+ion and ADP. The complex is strongly adsorbed at mercury electrode and has the following electrode reaction mechanism: Eu3++ADPEu3+ADP+e-Eu2+-ADP.

Synthesis and Crystal Structure of a New Potassium Yttrium Diphosphate Dihydrate KYP_2O_7·2H_2O

The dihydrated potassium yttrium diphosphate, KYP2O7·2H2O, has been synthesized for the first time. Single-crystal XRD study has allowed the determination of its structure and correct formula. It crystallizes in the monoclinic system, space group P21/c, with the cell parameters a = 7.7069（3）, b = 10.5801（4）, c = 10.0204（5）A,β = 93.24（3）A, V= 815.76（6）A^3, Z= 4, Mr = 337.98, F（000） = 656, Dc = 2.752 g/cm^3 and/t = 8.073 mm^-1. The single-crystal structure was solved from 1856 unique reflections with the final R = 0.0365 and wR = 0.0772, refined with 119 parameters. The atomic arrangement of KYP2O7·2H2O is built by the P2O7 groups, the YO7 and the KO10 polyhedrons which are connected by corner and edge-sharing to form a three-dimensional framework. Water molecules are directly bonded to the Y and K atoms, and they are located in channels running along the a direction.

THE REGULATORY EFFECT OF NUCLEOSIDE DIPHOSPHATE KINASE ON G－PROTEIN AND G－PROTEIN MEDIATED PHOSPHOLIPASE C

The effect of nucleoside diphosphate kinase (NDPK) on the activrty of guanine nucleotide regulatory protein (G-protein) mediated phospholipase C(PLC) and on the [35S]GTPTτS binding of G-protein was investigated in this work in order to demonstrate the mechanism behind the regulation of G-protein and its effector PLC by NDPK. The stimulation of PLC in turkey erythrocyte membrane by both GTP and GTPτS indicated that the PLC stimulation was mediated by G-protein. NDPK alone stimulated PLC activity. as well as the stimulation in the presence of GTP and GDP, in a dose-dependent manner. However. NDPK inhibited GTPτS-stimulated PLC. Furthermore, NDPK inhibited [35S]GTPτS binding of purified Gi-protein in a non-competitive manner. A hypothesis implying an important role of direct interaction of G-protein and NDPK in the regulation of their functions is suggested and discussed.

Poly adenosine diphosphate-ribosylation, a promising target for colorectal cancer treatment

The development of colorectal cancer(CRC)can result from changes in a variety of cellular systems within the tumor microenvironment.Particularly,it is primarily associated with genomic instability that is the gradual accumulation of genetic and epigenetic changes consisting of a characteristic set of mutations crucial for pathways in CRC progression.Based on this background,the potential to focus on poly[adenosine diphosphate(ADP)-ribose]polymerase(PARP)-1 and poly-ADP ribosylation(PARylation)as the main causes of malignant formation of CRC may be considered.One of the important functions of PARP-1 and PARylation is its deoxyribonucleic acid(DNA)repair function,which plays a pivotal role in the DNA damage response and prevention of DNA damage maintaining the redox homeostasis involved in the regulation of oxidation and superoxide.PARP-1 and PARylation can also alter epigenetic markers and chromatin structure involved in transcriptional regulation for the oncogenes or tumor suppressor genes by remodeling histone and chromatin enzymes.Given the high importance of these processes in CRC,it can be considered that PARP-1 and PARylation are at the forefront of the pathological changes required for CRC progression.Therefore,this review addresses the current molecular biological features for understanding the multifactorial function of PARP-1 and PARylation in CRC related to the aforementioned roles;furthermore,it presents a summary of recent approaches with PARP-1 inhibition in non-clinical and clinical studies targeting CRC.This understanding could help embrace the importance of targeting PARP-1 and PARylation in the treatment of CRC,which may present the potential to identify various research topics that can be challenged both nonclinically and clinically.

Clinical study of applying fructose-1,6-diphosphate and captopril to enhance the protective effects of cardioplegia solution on ischemic myocardium

In the present experiment,fructose-1,6-diphosphate（FDP）and captopril（Cap）wereadded to the cold potassium cardioplegia solution and the levels of malondialdehyde（MDA）,cre-atine phosphokinase MB（CPK-MB）,thromboxane B（TXB2）and 6-keto-PGF1α in plasma weremeasured during open-heart surgery.Quantitative study of myocardial ultrastructure and obser-vation of cardiac resuscitation were also undertaken.The findings suggested that FDP,especiallywhen combined with Cap could significantly strengthen the protective effects of cold potassiumcardioplegia solution on ischemic myocardium.

Nucleoside diphosphate-linked moiety X-type motif 15 R139C genotypes impact 6-thioguanine nucleotide cut-off levels to predict thiopurine-induced leukopenia in Crohn’s disease patients

BACKGROUND Thiopurine-induced leukopenia(TIL)is a life-threatening toxicity and occurs with a high frequency in the Asian population.Although nucleoside diphosphate-linked moiety X-type motif 15(NUDT15)variants significantly improve the predictive sensitivity of TIL,more than 50%of cases of this toxicity cannot be predicted by this mutation.The potential use of the 6-thioguanine nucleotide(6TGN)level to predict TIL has been explored,but no decisive conclusion has been reached.Can we increase the predictive sensitivity based on 6TGN by subgrouping patients according to their NUDT15 R139C genotypes?AIM To determine the 6TGN cut-off levels after dividing patients into subgroups according to their NUDT15 R139C genotypes.METHODS Patients’clinical and epidemiological characteristics were collected from medical records from July 2014 to February 2017.NUDT15 R139C,thiopurine S methyltransferase,and 6TGN concentrations were measured.RESULTS A total of 411 Crohn’s disease patients were included.TIL was observed in 72 individuals with a median 6TGN level of 323.4 pmol/8×10^8 red blood cells(RBC),which was not different from that of patients without TIL(P=0.071).Then,we compared the 6TGN levels based on NUDT15 R139C.For CC(n=342)and CT(n=65)genotypes,the median 6TGN level in patients with TIL was significantly higher than that in patients without(474.8 vs 306.0 pmol/8×10^8 RBC,P=9.4×10-^5;291.7 vs 217.6 pmol/8×10^8 RBC,P=0.039,respectively).The four TT carriers developed TIL,with a median 6TGN concentration of 135.8 pmol/8×10^8 RBC.The 6TGN cut-off levels were 411.5 and 319.2 pmol/8×108 RBC for the CC and CT groups,respectively.CONCLUSION The predictive sensitivity of TIL based on 6TGN is dramatically increased after subgrouping according to NUDT15 R139C genotypes.Applying 6TGN cut-off levels to adjust thiopurine therapies based on NUDT15 is strongly recommended.

Cloning And Characterization Of A Geranylgeranyl Diphosphate Synthase Gene From Taxus Chinensis

Taxol(Paclitaxel)is a diterpene from Taxus species and has been used in treatment of various kinds of cancers.Geranylgeranyl diphosphate synthase(GGPPS)catalyzes the formation of geranylgeranyl diphosphate(GGPP,the common precursor for diterpenes and plays a key role in taxol biosynthesis.Here we report a functional GGPPS gene from Taxus chinensis(designated TcGGPPS).TcGGPPS is an intron free gene and has a 1,182-bp open reading frame encoding a polypeptide of 393 amino acid residues with a calculated molecular mass of 42.63 kDa and an isoelectric point of 5.58.The catalytic activity of TcGGPPS for production of GGPP was verified by a color enhancement assay in the Escherichia coli cells harboring plasmid pAC-BETA.Multiple sequence alignment indicates that TcGGPPS is a little different in sequence from the functional GGPPS genes from other Taxus species such as T.canadensis,T.media and T.wallichiana,which are almost identical to each other.Protein structure prediction by using bioinformatics reveals that TcGGPPS consists of 52.2%α-helix,10.9%extended strand,8.4%β-turn and 28.5%random coil,and has a three-dimensional structure highly similar to the structurally known Sinapis alba GGPPS.In silicon predictions also demonstrate that TcGGPPS has a plastid-targeting peptide at the N-terminus,suggesting it is responsible for the synthesis of GGPP in plastids.

Fructose 1,6-diphosphate alleviates myocardial ischemia reperfusion injury in rats through JAK2/STAT3 pathway

Objective: To study the effect of fructose 1,6-diphosphate(FDP) on myocardial ischemia reperfusion injury in rats and its molecular mechanism.Methods: Male SPF SD rats were selected as experimental animals and randomly divided into four groups.Sham group received sham operation, I/R group were made into myocardial ischemia reperfusion injury models, FDP group were made into myocardial ischemia reperfusion injury models and then were given FDP intervention, and FDP+AG490 group were made into myocardial ischemia reperfusion injury models and then were given FDP and JAK2 inhibitor AG490 intervention.Results: CK, CK-MB, c Tn I and LDH contents in serum as well as Bax and Caspase-3 protein expression in myocardial tissue of I/R group were significantly higher than those of Sham group whereas Bcl-2, p-JAK2 and p-STAT3 protein expression in myocardial tissues were significantly lower than those of Sham group; CK, CK-MB, c Tn I and LDH contents in serum as well as Bax and Caspase-3 protein expression in myocardial tissue of FDP group were significantly lower than those of I/R group whereas Bcl-2, p-JAK2 and p-STAT3 protein expression in myocardial tissue were significantly higher than those of I/R group; CK, CK-MB, c Tn I and LDH contents in serum as well as Bax and Caspase-3 protein expression in myocardial tissue of FDP+AG490 group were significantly higher than those of FDP group whereas Bcl-2 protein expression in myocardial tissue was significantly lower than that of FDP group.Conclusion: FDP could reduce the myocardial ischemia reperfusion injury in rats by activating the JAK2/STAT3 pathway.

Repeated febrile convulsions impair hippocampal neurons and cause synaptic damage in immature rats: neuroprotective effect of fructose-1,6-diphosphate

Fructose-1,6-diphosphate is a metabolic intermediate that promotes cell metabolism. We hypothesize that fructose-1,6-diphosphate can protect against neuronal damage induced by febrile convulsions. Hot-water bathing was used to establish a repetitive febrile convulsion model in rats aged 21 days, equivalent to 3–5 years in humans. Ninety minutes before each seizure induction, rats received an intraperitoneal injection of low- or high-dose fructose-1,6-diphosphate（500 or 1,000 mg/kg, respectively）. Low- and high-dose fructose-1,6-diphosphate prolonged the latency and shortened the duration of seizures. Furthermore, high-dose fructose-1,6-diphosphate effectively reduced seizure severity. Transmission electron microscopy revealed that 24 hours after the last seizure, high-dose fructose-1,6-diphosphate reduced mitochondrial swelling, rough endoplasmic reticulum degranulation, Golgi dilation and synaptic cleft size, and increased synaptic active zone length, postsynaptic density thickness, and synaptic interface curvature in the hippocampal CA1 area. The present findings suggest that fructose-1,6-diphosphate is a neuroprotectant against hippocampal neuron and synapse damage induced by repeated febrile convulsion in immature rats.

PRODUCTION OF FRUCTOSE-l,6-DIPHOSPHATE(FDP) BY PERMEABILIZED SACCHAROMYCES CEREVISIAE AND A KINETIC MODEL FOR FDP ACCUMULATION

Permeable yeast cells were used in the batch production of fructose-1,6-diphosphate(FDP).The optimum reaction conditions were reported to be:reaction temperature 30℃,tolueneconcentration 8%(V/V),and initial ratio of glucose to inorganic phosphorus(Pi)10:1.Addition ofAMP was found to be very beneficial to the FDP production.A multienzyme system model for FDPaccumulation was developed,in which FDP was regarded as a substrate of phosphor-fructokinase(PFK),to simulate the activation effect of FDP on PFK.The model simulations were in good agree-ment with the experimental data.

The effect of stunned myocardium on heart function and the protection of fructose－1，6－diphosphate on it

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The Effect of Fructose-1,6-diphosphate and HTK Solution on Protecting Primary Cardiac Muscle Cells of Rat with Cold Preservation

In this study we tried to investigate the effect of fructose-1,6-diphosphate and HTK solution on protecting primary cardiac muscle cells of rat with cold preservation. The primary cardiac muscle cells of rat were cultured in vitro with four preservation solutions respectively: 0.9 % sodium chloride solution (group A), FDP (group B), HTK solution (group C) and a mixture of FDP and HTK solution (group D). The cells were preserved for 6, 8 and 10 h at 0-4 ℃. The values of AST and LDH-L and the Na+-K+ ATPase activity in cardiac muscle cells were detected, and the survival rate of cardiac muscle cells was detected with trypan blue staining. The values of AST and LDH-L in group C and group D were remarkable lower those in group A and group B (P<0.001), while the Na+-K+ ATPase activity and the survival rate of cells in group C and group D were much higher than those in group A and group B (P<0.001). The values of AST and LDH-L after 6 hours in group D decreased much more than those in group C (P<0.01), while the Na+-K+ ATPase activity and the survival rate of cells in group D improved more than those in group C (P<0.01). Both of the HTK solution and the mixture of HTK and FDP solution have an evident effect on protecting the primary cardiac muscle cells of rat in vitro with cold preservation, Compared with the HTK solution, the mixture solution has a better short-term protective effect.