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.

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.

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.

The ZmHSF08-ZmUGT92A1 module regulates heat tolerance by altering reactive oxygen species levels in maize

GTs(Glycosyltransferases)are important in plant growth and abiotic stresses.However,its role in maize heat response is far from clear.Here,we describe the constitutively expressed UDP-glycosyltransferase ZmUGT92A1,which has a highly conserved PSPG box and is localized in chloroplasts,is induced under heat stress.Functional disruption of ZmUGT92A1 leads to heat sensitivity and reactive oxygen species accumulation in maize.Metabolomics analysis revealed that ZmUGT92A1 affected multiple metabolic pathways and altered the metabolic homeostasis of flavonoids under heat stress.In vitro assay showed ZmUGT92A1 exhibits glycosyltransferase activity on flavonoids and hormones.Additionally,we identified a rapidly heat-induced transcription factor,ZmHSF08,which can directly bind and repress the promoter region of ZmUGT92A1.The ZmHSF08 overexpression line exhibits heat sensitivity and reactive oxygen species accumulation.These findings reveal that the ZmHSF08-ZmUGT92A1 module plays a role in heat tolerance in maize and provide candidate strategies for the development of heat-tolerant varieties.

Correlation between UGT1A1 Polymorphism and Neonatal Hyperbilirubinemia of Neonates in Wuhan

This study attempts to discuss the correlation between UGT1A1＊28 as uridine diphosphate glucuronosyltransferase gene promoter and coding region Gly71 Arg gene polymorphism with neonatal hyperbilirubinemia of neonates in Wuhan. A total of 168 neonates were divided into the hyperbilirubinemia group（case group, n=108） and healthy neonates group（control group, n=60）. Their DNA was obtained through blood extraction. The gene exon mutation of UGT1A1 was detected by Sanger sequencing, which revealed the relationship between UGT1A1＊28 and Gly71 Arg polymorphism with neonatal hyperbilirubinemia of neonates. The results showed that：（1） The frequency of UGT1A1＊28 allele mutation in the case group and the control group was 9.3% and 10% respectively, with the difference being not significant between the two groups（P〉0.05）.（2） The frequency of Gly71 Arg allele mutation in the case group and the control group was 35.1% and 21.7% respectively, with the difference being significant between the two groups（P〈0.01）.（3） The serum bilirubin level of Gly71 Arg mutant homozygous and heterozygous subgroups（n=66） in the case group was 302.7±31.4 μmol/L, which was significantly higher than 267.3±28.5 μmol/L of the wild subgroup（n=42）（P〈0.01）. It was suggested that the occurrence of neonatal hyperbilirubinemia of neonates in Wuhan was not associated with UGT1A1＊28 gene polymorphism, but closely with the Gly71 Arg gene polymorphism. Meanwhile, the Arg allele mutation was related to the degree of jaundice.

Etiology analysis for term newborns with severe hyperbilirubinemia in eastern Guangdong of China

BACKGROUND Neonatal hyperbilirubinemia is one of the common diseases of newborns that typically presents with yellow staining of skin,resulting in sequelaes such as hearing loss,motor and intellectual development disorders,and even death.The pathogenic factors of neonatal hyperbilirubinemia are complex.Different cases of hyperbilirubinemia may have a single or mixed etiology.AIM To explore the etiological characteristics of severe hyperbilirubinemia in term newborns of eastern Guangdong of China.METHODS Term newborns with severe hyperbilirubinemia in one hospital from January 2012 to December 2021 were retrospectively analyzed.The etiology was determined according to the laboratory results and clinical manifestations.RESULTS Among 1602 term newborns with hyperbilirubinemia in eastern Guangdong of China,32.20%(580/1602)was severe hyperbilirubinemia.Among the causes of severe hyperbilirubinemia,neonatal hemolysis accounted for 15.17%,breast milk jaundice accounted for 12.09%,infection accounted for 10.17%,glucose-6-phosphate dehydrogenase(G6PD)deficiency accounted for 9.14%,and the coexistence of multiple etiologies accounted for 6.55%,unknown etiology accounted for 41.72%.ABO hemolysis and G6PD deficiency were the most common causes in the 20 cases with bilirubin encephalopathy.94 severe hyperbilirubinemia newborns were tested for uridine diphosphate glucuronosyl transferase 1A1(UGT1A1)*6 variant(rs4148323,c.211G>A,p.Arg71Gly),9 cases were 211 G to A homozygous variant,37 cases were 211 G to A heterozygous variant,and 48 cases were wild genotypes.CONCLUSION The main cause for severe hyperbilirubinemia and bilirubin encephalopathy in eastern Guangdong of China were the hemolytic disease of the newborns,G6PD deficiency and infection.UGT1A1 gene variant was also a high-risk factor for neonatal hyperbilirubinemia.Targeted prevention and treatment according to the etiology may reduce the occurrence of bilirubin encephalopathy and kernicterus.

羧基和咪唑基团在柚柠檬苦素类化合物糖基转移酶催化反应中的作用(英文)

Limonoid bitterness is a serious problem in the citrus industry worldwide. Limonoid glucosyltransferase is an enzyme that catalyzes the conversion of bitter limonoid into non-bitter limonoid glucoside while retaining the health benefit of limonoids in the juice. The immobilization of this enzyme in a column can solve the juice bitterness problem. More information about the catalytic residues of the enzyme is needed in this immobilization process. Glutamate/aspartate,histidine,lysine,tryptophan,serine,and cysteine residues were chemi-cally modified to investigate their roles in the catalytic function of limonoid glucosyltransferase. Inactivation of the enzyme following modi-fication of carboxyl and imidazole moieties was a consequence of a loss in substrate binding and catalysis in the glucosyltransfer reaction. The modification of a single histidine residue completely destroyed the ability of limonoid glucosyltransferase to transfer the D-glucopyranosyl unit. Tryptophan seemed to have some role in maintaining the active conformation of the catalytic site. Lysine also seemed to have some direct or indirect role in this catalysis but the modification of serine and cysteine did not have any effect on catalysis. Therefore,we conclude that the carboxyl and imidazole groups containing amino acids are responsible for the catalytic action of the enzyme.

Genetic analysison the association between polymorphisms of UGT1A1and GST and neonatal hyperbilirubinemia

Objective:To investigate whether polymorphisms of uridine diphosphoglucuronate-glucuronosyltransferase 1A1(UGT1A1)c.211G>A and glutathione S transferases(GST)gene(GSTT1and GSTM1)are associated with neonatal hyperbilirubinemia.Methods:A case-control study was performed.A multiplex polymerase chain reaction(PCR)was used to detect the GSTT1and GSTM1polymorphisms.Single nucleotide polymorphism of UGT1A1c.211G>A was identified by PCR combined with DNA sequencing.The effects and co-expression of UGT1A1c.211G>A,GSTT1and GSTM1gene polymorphisms on the development of neonatal hyperbilirubinemia were estimated.Results:A allele frequency of c.211G>A polymorphism of UGT1A1gene was 0.186in case group and 0.086in control group,respectively.A allele frequency of the polymorphism of UGT1A1gene in the case group was higher than that of the control group(χ2=5.968,P=0.022).The frequencies of GSTT1and GSTM1in the case group were similar to that of the control groups.Logistic regression analysis showed that UGT1A1c.211G>A variant and UGT1A1+GSTM1 mutation affected neonatal hyperbilirubinemia.Conclusion:UGT1A1c.211G>A gene polymorphism may be one risk factor involved in the development of neonatal hyperbilirubinemia,and GST gene polymorphism may not be associated with the development of neonatal hyperbilirubinemia in our study.The co-expression of UGT1A1c.211G>A and GSTM1polymorphisms may reduce the risk for neonatal hyperbilirubinemia development.

Advances in biosynthesis of triterpenoid saponins in medicinal plants

In recent years, biosynthesis of triterpenoid saponins in medicinal plants has been widely studied because of their active ingredients with diverse pharmacological activities. Various oxidosqualene cyclases, cytochrome P450 monooxygenases, uridine diphosphate glucuronosyltransferases, and transcription factors related to triterpenoid saponins biosynthesis have been explored and identified. In the biosynthesis of triterpenoid saponins, the progress of gene mining by omics-based sequencing, gene screening, gene function verification, catalyzing mechanism of key enzymes and gene regulation are summarized and discussed. By the progress of the biosynthesis pathway of triterpenoid saponins, the large-scale production of some triterpenoid saponins and aglycones has been achieved through plant tissue culture, transgenic plants and engineered yeast cells. However, the complex biosynthetic pathway and structural diversity limit the biosynthesis of triterpenoid saponins in different system. Special focus can further be placed on the systematic botany information of medicinal plants obtained from omics large dataset, and triterpenoid saponins produced by synthetic biology strategies, gene mutations and gene editing technology.

Inhibitory potential of three Yin-tonification herbal formulas on the activities of human major cytochrome P450 and UDP-glucuronosyltransferases isozymes in vitro

OBJECTIVE:To investigate the influence of Yin-tonification herbal formulas Jaeumganghwa-tang(Ziyin Jianghuo Tang,JEGHT),Ssanghwa-tang(Shuanghe Tang,SHT) and Yukmijihwang-tang(Liuwei Di huang Tang,YMJHT) on the activities of human major cytochrome P450(CYP450 s) and UDP-glucuronosyltransferases isozymes(UGTs) in vitro.METHODS:The activities of CYP450 s(CYP1 A2,CYP3 A4,CYP2 B6,CYP2 C9,CYP2 C19,CYP2 D6 and CYP2 E1) and UGTs(UGT1 A1,UGT1 A4 and UGT2 B7)were assessed using in vitro fluorescence-and luminescence-based enzyme assays,respectively.The effects of herbal formulas on the activities of CYP450 s and UGTs were presented as IC50 values.RESULTS:JEGHT showed the potent inhibition of the CYP2 D6 activity,with weak inhibition on the activities of CYP1 A2,CYP2 B6,CYP2 C9,CYP2 C19,CYP2 E1,CYP3 A4,UGT1 A1,UGT1 A4 and UGT2 B7.SHT inhibited the activities of CYP1 A2 and CYP2 E1,whereas the negligible inhibition of the activities of CYP2 B6,CYP2 C9,CYP2 C19,CYP2 D6,CYP3 A4,UGT1 A1,UGT1 A4 and UGT2 B7 through SHT was observed.YMJHT inhibited CYP2 E1 activity,with a negligible inhibition on the activities of CYP1 A2,CYP2 B6,CYP2 C9,CYP2 C19,CYP2 D6,CYP3 A4,UGT1 A1,UGT1 A4 and UGT2 B7.CONCLUSION:These findings provide information about the potential interactions between three Yin-tonification herbal formulas and conventional drugs.