Direct detection of a single[4Fe-4S]cluster in a tungsten-containing enzyme:Electrochemical conversion of CO_(2) into formate by formate dehydrogenase

The conversion of CO_(2) into fuels and valuable chemicals is one of the central topics to combat climate change and meet the growing demand for renewable energy.Herein,we show that the formate dehydrogenase from Clostridium ljungdahlii(ClFDH)adsorbed on electrodes displays clear characteristic voltammetric signals that can be assigned to the reduction and oxidation potential of the[4Fe-4S]^(2+/+)cluster under nonturnover conditions.Upon adding substrates,the signals transform into a specific redox center that engages in catalytic electron transport.ClFDH catalyzes rapid and efficient reversible interconversion between CO_(2) and formate in the presence of substrates.The turnover frequency of electrochemical CO_(2) reduction is determined as 1210 s^(-1) at 25℃ and pH 7.0,which can be further enhanced up to 1786 s^(-1) at 50℃.The Faradaic efficiency at−0.6 V(vs.standard hydrogen electrode)is recorded as 99.3%in a 2-h reaction.Inhibition experiments and theoretical modeling disclose interesting pathways for CO_(2) entry,formate exit,and OCN−competition,suggesting an oxidation-state-dependent binding mechanism of catalysis.Our results provide a different perspective for understanding the catalytic mechanism of FDH and original insights into the design of synthetic catalysts.

F-box only protein 2 exacerbates non-alcoholic fatty liver disease by targeting the hydroxyl CoA dehydrogenase alpha subunit

BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is a major health burden with an increasing global incidence.Unfortunately,the unavailability of knowledge underlying NAFLD pathogenesis inhibits effective preventive and therapeutic measures.AIM To explore the molecular mechanism of NAFLD.METHODS Whole genome sequencing(WGS)analysis was performed on liver tissues from patients with NAFLD(n=6)and patients with normal metabolic conditions(n=6)to identify the target genes.A NAFLD C57BL6/J mouse model induced by 16 wk of high-fat diet feeding and a hepatocyte-specific F-box only protein 2(FBXO2)overexpression mouse model were used for in vivo studies.Plasmid transfection,co-immunoprecipitation-based mass spectrometry assays,and ubiquitination in HepG2 cells and HEK293T cells were used for in vitro studies.RESULTS A total of 30982 genes were detected in WGS analysis,with 649 up-regulated and 178 down-regulated.Expression of FBXO2,an E3 ligase,was upregulated in the liver tissues of patients with NAFLD.Hepatocyte-specific FBXO2 overexpression facilitated NAFLD-associated phenotypes in mice.Overexpression of FBXO2 aggravated odium oleate(OA)-induced lipid accumulation in HepG2 cells,resulting in an abnormal expression of genes related to lipid metabolism,such as fatty acid synthase,peroxisome proliferator-activated receptor alpha,and so on.In contrast,knocking down FBXO2 in HepG2 cells significantly alleviated the OA-induced lipid accumulation and aberrant expression of lipid metabolism genes.The hydroxyl CoA dehydrogenase alpha subunit(HADHA),a protein involved in oxidative stress,was a target of FBXO2-mediated ubiquitination.FBXO2 directly bound to HADHA and facilitated its proteasomal degradation in HepG2 and HEK293T cells.Supplementation with HADHA alleviated lipid accumulation caused by FBXO2 overexpression in HepG2 cells.CONCLUSION FBXO2 exacerbates lipid accumulation by targeting HADHA and is a potential therapeutic target for NAFLD。

2型糖尿病合并慢性牙周炎患者血清LRG1、LDH与牙周指标和牙周病变程度的关系

目的探究2型糖尿病(T2DM)合并慢性牙周炎(CP)患者血清富含亮氨酸α-2糖蛋白1(LRG1)、乳酸脱氢酶(LDH)与牙周指标和牙周病变程度的关系。方法选取2022年7月至2023年7月宁夏医科大学总医院口腔医院收治的112例T2DM合并CP患者(T2DM合并CP组),根据牙周病变程度将其分为轻度、中度和重度组;选取同期本院112例单纯CP患者(CP组),再选取112例单纯T2DM患者(T2DM组);检测LRG1、LDH和牙周指标;Pearson法分析血清LRG1、LDH及二者与牙周指标的相关性;重度T2DM合并CP的影响因素采用多因素logistic回归分析;绘制ROC曲线分析血清LRG1、LDH对重度T2DM合并CP的诊断价值。结果CP组、T2DM组以及T2DM合并CP组LRG1、LDH水平依次升高(P<0.05)。轻度、中度和重度组血清LRG1、LDH、附着丧失(AL)、牙周探诊深度(PD)、牙龈出血指标(BI)水平依次升高(P<0.05)。根据Pearson相关性分析得知,血清LRG1与LDH呈正相关(P<0.05),二者均与AL、PD、BI呈正相关(P<0.05)。根据logistic回归分析得知LRG1、LDH、AL、PD、BI均为影响重度T2DM合并CP的因素(P<0.05)。根据ROC曲线得知血清LRG1和LDH二者联合诊断重度T2DM合并CP的AUC为0.910,两者联合优于各自单独诊断(Z_(联合vs LRG1)=2.659、Z_(联合vs LDH)=2.627,P<0.05)。结论LRG1、LDH在T2DM合并CP患者血清中显著升高,两者与牙周指标和牙周病变程度有关。

Role of aldehyde dehydrogenase 2 in ischemia reperfusion injury:An update

Aldehyde dehydrogenase 2(ALDH2) is best known for its critical detoxifying role in liver alcohol metabolism. However, ALDH2 dysfunction is also involved in a wide range of human pathophysiological situations and is associated with complications such as cardiovascular diseases, diabetes mellitus, neurodegenerative diseases and aging. A growing body of research has shown that ALDH2 provides important protection against oxidative stress and the subsequent loading of toxic aldehydes such as 4-hydroxy-2-nonenal and adducts that occur in human diseases, including ischemia reperfusion injury(IRI). There is increasing evidence of its role in IRI pathophysiology in organs such as heart, brain, small intestine and kidney; however, surprisingly few studies have been carried out in the liver, where ALDH2 is found in abundance. This study reviews the role of ALDH2 in modulating the pathways involved in the pathophysiology of IRI associated with oxidative stress, autophagy and apoptosis. Special emphasis is placed on the role of ALDH2 in different organs, on therapeutic "preconditioning" strategies, and on the use of ALDH2 agonists such as Alda-1, which may become a useful therapeutic tool for preventing the deleterious effects of IRI in organ transplantation.

Aldehyde dehydrogenase 2 overexpression inhibits neuronal apoptosis after spinal cord ischemia/reperfusion injury

Aldehyde dehydrogenase 2（ALDH2）is an important factor in inhibiting oxidative stress and has been shown to protect against renal ischemia/reperfusion injury.Therefore,we hypothesized that ALDH_2 could reduce spinal cord ischemia/reperfusion injury.Spinal cord ischemia/reperfusion injury was induced in rats using the modified Zivin＇s method of clamping the abdominal aorta.After successful model establishment,the agonist group was administered a daily consumption of 2.5%alcohol.At 7 days post-surgery,the Basso,Beattie,and Bresnahan score significantly increased in the agonist group compared with the spinal cord ischemia/reperfusion injury group.ALDH_2expression also significantly increased and the number of apoptotic cells significantly decreased in the agonist group than in the spinal cord ischemia/reperfusion injury group.Correlation analysis revealed that ALDH_2 expression negatively correlated with the percentage of TUNEL-positive cells（r=-0.485,P〈0.01）.In summary,increased ALDH_2 expression protected the rat spinal cord against ischemia/reperfusion injury by inhibiting apoptosis.

Association of genetic polymorphisms of aldehyde dehydrogenase-2 with esophageal squamous cell dysplasia

AIM:To demonstrate the possible associations between genetic polymorphisms of aldehyde dehydrogenase-2(ALDH2) and esophageal squamous cell dysplasia(ESCD).METHODS:All participants came from an area of high incidence of esophageal cancer and underwent an endoscopic staining examination;biopsies were taken from a non-staining area of the mucosa and diagnosed by histopathology.Based on the examinations,the subjects were divided into the control group with normal esophageal squamous epithelial cells and the ESCD group.ALDH2 genotypes of 396 cases were determined including 184 ESCD cases and 212 controls.The odds ratio(OR) and 95% confidence intervals(95% CI) were calculated by binary logistic regression models.RESULTS:The distribution of ALDH2 genotypes showed significant differences between the two groups.The adjustment factors were gender and age in the logistic regression models.Compared with 2*2/2*2 genotype,2*1/2*1 genotype was found to be a risk factor for ESCD,and the OR(95% CI) was 4.50(2.21-9.19).There were significant correlations between ALDH2 genotypes and alcohol drinking/smoking/history of esophageal cancer.CONCLUSION:The ALDH2 polymorphism is significantly associated with ESCD.

2型糖尿病合并视网膜病变患者血清ALDH2和CAT活性检测及临床意义

目的分析2型糖尿病(T2DM)合并糖尿病视网膜病变(DR)患者血清乙醛脱氢酶2(ALDH2)和过氧化氢酶(CAT)活性,并探讨其临床诊断价值。方法选取该院2020年4月至2021年11月206例T2DM患者,根据视网膜是否发生病变分为单纯T2DM组(T2DM组,n=103)和T2DM合并DR组(T2DM+DR组,n=103),另选取该院同期103例体检健康者为对照组。检测血清ALDH2、CAT活性,Pearson相关性分析T2DM合并DR患者血清ALDH2、CAT与糖化血红蛋白、甘油三酯、空腹血糖(FBG)、餐后1 h血糖(1 hPG)及胰岛素抵抗指数(HOMA-IR)的关系,多因素Logistic回归分析T2DM合并DR的影响因素,受试者工作特征(ROC)曲线分析血清ALDH2、CAT对T2DM合并DR的临床诊断价值。结果对照组、T2DM组、T2DM+DR组患者血清ALDH2、CAT活性依次逐渐降低(P<0.05)。多因素Logistic回归分析结果显示,糖化血红蛋白、1 hPG、HOMA-IR、糖尿病病程及ALDH2、CAT活性是T2DM合并DR的影响因素(P<0.05)。Pearson相关性分析结果显示,T2DM合并DR患者血清ALDH2、CAT与糖化血红蛋白、甘油三酯、FBG、1 hPG及HOMA-IR均呈负相关(P<0.05)。ROC曲线分析结果显示,ALDH2和CAT联合诊断T2DM合并DR的曲线下面积(AUC)明显大于ALDH2单独诊断的AUC(Z=2.563,P=0.010)及CAT单独诊断的AUC(Z=1.984,P=0.047)。结论T2DM合并DR患者血清ALDH2、CAT活性降低,二者联合检测对T2DM合并DR具有较高的诊断价值。

Polymorphisms of alcohol dehydrogenase-2 and aldehyde dehydrogenase-2 and esophageal cancer risk in Southeast Chinese males

AIM:To evaluate the impact of alcohol dehydrogenase-2(ADH2) and aldehyde dehydrogenase-2(ALDH2) polymorphisms on esophageal cancer susceptibility in Southeast Chinese males.METHODS:Two hundred and twenty-one esophageal cancer patients and 191 healthy controls from Taixing city in Jiangsu Province were enrolled in this study.ADH2 and ALDH2 genotypes were examined by polymerase chain reaction and denaturing high-performance liquid chromatography.Unconditional logistic regression was used to calculate the odds ratios(OR) and 95% confi dence interval(CI) .RESULTS:The ADH G allele carriers were more susceptible to esophageal cancer,but no association was found between ADH2 genotypes and risk of esophageal cancer when disregarding alcohol drinking status.Regardless of ADH2 genotype,ALDH2G/A or A/A carriers had significantly increased risk of developing esophageal cancer,with homozygous individuals showing higher esophageal cancer risk than those who were heterozygous.A signif icant interaction between ALDH2 and drinking was detected regarding esophageal cancer risk;the OR was 3.05(95% CI:1.49-6.25) .Compared with non-drinkers carrying both ALDH2 G/G and ADH2 A/A,drinkers carrying both ALDH2 A allele and ADH2 G allele showed a signif icantly higher risk of developing esophageal cancer(OR = 8.36,95% CI:2.98-23.46) .CONCLUSION:Both ADH2 G allele and ALDH2 A allele significantly increase the risk of esophageal cancer development in Southeast Chinese males.ALDH2 A allele significantly increases the risk of esophageal cancer development especially in alcohol drinkers.Alcohol drinkers carrying both ADH2 G allele and ALDH2 A allele have a higher risk of developing esophageal cancer.

Chronic stress causes protein kinase C epsilon-aldehyde dehydrogenase 2 signaling pathway perturbation in the rat hippocampus and prefrontal cortex,but not in the myocardium

Chronic stress is strongly associated with the occurrence and development of depression and cardiovascular disease.Stress can induce altered mitochondrial function and activation of apoptosis in the cardio-cerebral system.However,it is unknown whether the protein kinase C ε（PKCε）-aldehyde dehydrogenase 2（ALDH2） pathway is altered under chronic stress,and this study sought to address this question.A rat model of depression was established using a chronic unpredictable mild stress（CUMS） protocol.After experiencing CUMS for 4 weeks,the sucrose preference test and the forced swim test verified depressive-like behaviors.Enzyme linked immunosorbent assays showed that ALDH2 activity was decreased in the rat hippocampus and prefrontal cortex,but was not altered in the myocardium.Western blot assays demonstrated reduced levels of ALDH2 and PKCε,but increased levels of 4-hydroxy-2-nonenal（4 HNE） adducts.Caspase-3 expression did not obviously alter,but active forms of caspase-3 were increased in the hippocampus and prefrontal cortex.In the myocardium,expression of ALDH2,PKCε and 4 HNE adducts did not remarkably alter;while caspase-3 expression was reduced and the active forms of caspase-3 were upregulated.Pearson＇s correlation test demonstrated that expression of 4 HNE adducts was positively correlated with levels of the active forms of caspase-3 in the hippocampus and prefrontal cortex,but not in the myocardium.In conclusion,chronic stress can damage the PKCε-ALDH2 signaling pathway in the hippocampus and prefrontal cortex,but not in the myocardium.Moreover,4 HNE is associated with active forms of caspase-3 in the hippocampus and prefrontal cortex.

11β-hydroxysteroid dehydrogenase types 1 and 2. in postnatal development of rat testis： gene express,on, localization and regulation by luteinizing hormone and androgens

11β-hydroxysteroid dehydrogenase type 1 （11β-HSD1） and type 2 （11β-HSD2） are expressed in rat testis, where they regulate the local concentrations of glucocorticoids. Here, we investigated the expression and localization of 11β-HSD in rat testis during postnatal development, and the regulation of these genes by luteinizing hormone （LH） and androgens, mRNA and protein levels were analyzed by quantitative real-time-polymerase chain reaction and western blotting, respectively, in testes collected from rats at postnatal day （PND） 7, 14, 21, 35, and 90, and from rats treated with LH, 7α.methyl-19-nortestosterone （MENT） and testosterone at PND 21 and PND 90. Immunohistochemical staining was used to identify the localization of the 11β-HSD in rat testis at PND 7, 14, and 90. We found that 11β-HSD1 expression was restricted to the interstitial areas, and that its levels increased during rat testis development. In contrast, whereas 11β-HSD2 was expressed in both the interstitial areas and seminiferous tubules at PND 7, it was present only in the interstitial areas at PND 90, and its levels declined during testicular development. Moreover, 11β-HSD1 mRNA was induced by LH in both the PND 21 and 90 testes and by MENT at PND 21, whereas 11β-HSD2 mRNA was induced by testosterone and MENT in the PND 21 testis and by LH in the PND 90 testis. In conclusion, our study indicates that the 11β-HSD1 and 11β-HSD2 genes have distinct patterns of spatiotemporal expression and hormonal regulation during postnatal development of the rat testis.

Prokaryotic Expression of Gene Encoding Glutamate Dehydrogenase of Streptococcus suis Serotype 2 and Preparation of Polyclonal Antibodies against Its Expressed Products

[ Objective] To obtain detection antigen for diagnosis of Streptococcus suis infection. [ Method] The complete ORF of glutamate dehy- drogenase （GDH） gene was amplified from the genomic DNA of Streptococcus suis serotype 2 strain SC22 isolated in Sichuan Province by poly- merase chain reaction （PCR）. The resulting product was cloned into the prokaryotic expression vector pET-30a, which was then transformed into E. coil BL21 （DE3）. The identified positive transformants were screened for expression induced by IPTG. The expression products were subjected to SDS-PAGE and the recombinant protein was purified by nickel ion-agarose affinity chromatography. New Zealand rabbits were immunized with the purified recombinant GDH protein to prepare polyclonal antibodies. Titers of the anti-serum were determined by indirect ELISA and Western blot assay. [ Result] The recombinant GDH protein was effectively expressed in the host bacteria, and highly pure recombinant protein was obtained by nickel ion-agarose affinity chromatography. High-titer anti-serum against the recombinant protein was obtained. As evidenced by western blot as- say, the sera could react specifically with the lysates of all detected Streptococcus suis strains. In addition, the recombinant GDH protein could re- act specifically with serum samples collected from five pigs experimentally infected by strain SC22. [ Conclusion] The expressed GDH fusion protein has some common epitopes of natural GDH and can be used as detection antigen to develop ELISA and other diagnostic methods.

Aldehyde dehydrogenase 2 preserves mitochondrial morphology and attenuates hypoxia/reoxygenationinduced cardiomyocyte injury

BACKGROUND:Disturbance of mitochondrial fi ssion and fusion(termed mitochondrial dynamics)is one of the leading causes of ischemia/reperfusion(I/R)-induced myocardial injury.Previous studies showed that mitochondrial aldehyde dehydrogenase 2(ALDH2)conferred cardioprotective effect against myocardial I/R injury and suppressed I/R-induced excessive mitophagy in cardiomyocytes.However,whether ALDH2 participates in the regulation of mitochondrial dynamics during myocardial I/R injury remains unknown.METHODS:In the present study,we investigated the effect of ALDH2 on mitochondrial dynamics and the underlying mechanisms using the H9c2 cells exposed to hypoxia/reoxygenation(H/R)as an in vitro model of myocardial I/R injury.RESULTS:Cardiomyocyte apoptosis was significantly increased after oxygen-glucose deprivation and reoxygenation(OGD/R),and ALDH2 activation largely decreased the cardiomyocyte apoptosis.Additionally,we found that both ALDH2 activation and overexpression significantly inhibited the increased mitochondrial fission after OGD/R.Furthermore,we found that ALDH2 dominantly suppressed dynamin-related protein 1(Drp1)phosphorylation(Ser616)and adenosine monophosphate-activated protein kinase(AMPK)phosphorylation(Thr172)but not interfered with the expression levels of mitochondrial shaping proteins.CONCLUSIONS:We demonstrate the protective effect of ALDH2 against cardiomyocyte H/R injury with a novel mechanism on mitochondrial fission/fusion.

Polymorphisms of alcohol dehydrogenase 2 and aldehyde dehydrogenase 2 and colorectal cancer risk in Chinese males

AIM: To evaluate the relationship between drinking and polymorphisms of alcohol dehydrogenase 2 (ADH2) and/or aldehyde dehydrogenase 2 (ALDH2) for risk of colorectal cancer (CRC) in Chinese males. METHODS: A case-control study was conducted in 190 cases and 223 population-based controls. ADH2 Arg47His (G-A) and ALDH2 Glu487Lys (G-A)genotypes were identified by PCR and denaturing high-performance liquid chromatography (DHPLC). Information on smoking and drinking was collected and odds ratio (OR) was estimated. RESULTS: The ADH2 A/A and ALDH2 G/G genotypes showed moderately increased CRC risk. The age- and smoking-adjusted OR for ADH2 A/A relative to G/A and G/G was 1.60 (95% CI=1.08-2.36), and the adjusted OR for ALDH2 G/G relative to G/A and A/A was 1.79 (95% CI=1.19-2.69). Signif icant interactions between ADH2, ALDH2 and drinking were observed. As compared to the subjects with ADH2 G and ALDH2 A alleles, those with ADH2 A/A and ALDH2 G/G genotypes had a signif icantly increased OR (3.05, 95% CI= 1.67-5.57). The OR for CRC among drinkers with the ADH2 A/A genotype was increased to 3.44 (95% CI= 1.84-6.42) compared with non-drinkers with the ADH2 G allele. The OR for CRC among drinkers with the ALDH2 G/G genotype was also increased to 2.70 (95% CI= 1.57-4.66) compared with non-drinkers with the ALDH2 A allele. CONCLUSION: Polymorphisms of the ADH2 and ALDH2 genes are significantly associated with CRC risk. There are also signifi cant gene-gene and gene- environment interactions between drinking and ADH2 and ALDH2 polymorphisms regarding CRC risk in Chinese males.

亚甲基四氢叶酸脱氢酶2是异质性细胞叠套结构形成的负调控分子

异质性细胞叠套结构(heterotypic cell-in-cell structure,heCICs)介导独特的非自主性细胞死亡,广泛参与肿瘤发生、发展和临床预后等多种重要的病理学过程。亚甲基四氢叶酸脱氢酶2(methylenetetrahydrofolata dehydrogenase 2,MTHFD2)作为一碳代谢的关键酶之一,在多种肿瘤细胞中高表达。在本研究中,为了探究MTHFD2对heCICs形成能力的影响,首先应用活细胞染料对肝癌细胞和免疫细胞分别进行标记,利用荧光显微镜对细胞进行拍摄分析建立heCICs模型。进一步通过RNAi技术瞬时敲低细胞中的MTHFD 2,结果显示,MTHFD 2敲低后,PLC/PRF/5和Hep3B分别与免疫细胞形成heCICs的能力显著升高(均P<0.01)。通过同源重组方法构建MTHFD2重组表达质粒,进一步构建MTHFD2过表达细胞系;将过表达细胞系与免疫细胞共培养检测MTHFD2过表达对heCICs形成能力的影响,结果显示,过表达MTHFD2后heCICs形成率显著降低(均P<0.001)。综上,本研究表明,MTHFD2是heCICs形成的负调控因子,为靶向MTHFD2促进heCICs形成增强免疫细胞胞内杀伤提供了研究基础。

醛脱氢酶2与人类疾病的关系及其小分子激动剂研究

醛脱氢酶2(ALDH2)是人体内重要的抗氧化应激损伤因子之一,而较高比例的东亚人携带ALDH2失活突变基因。与ALDH2密切相关的疾病有很多,如心血管疾病、神经退行性疾病和肝脏疾病等。近期研究还发现ALDH2与铁死亡也有联系。正因如此,ALDH2逐渐成为上述相关疾病治疗的潜在靶点,研究者报道了其多个类型的小分子激动剂,展现出一定的应用前景。本文重点介绍ALDH2的结构、功能、与人类疾病的关系以及其激动剂的研究进展。

多发性骨髓瘤患者血清β_(2)-微球蛋白、肿瘤坏死因子-α、乳酸脱氢酶检测及临床意义

目的:检测多发性骨髓瘤患者血清β_(2)-微球蛋白(β_(2)-MG)、肿瘤坏死因子-α(TNF-α)、乳酸脱氢酶(LDH)水平,分析其临床意义。方法:选取多发性骨髓瘤患者101例为研究组,选取同期性别比例、年龄相似的非多发性骨髓瘤患者50例为对照组。比较两组血清β_(2)-MG、TNF-α、LDH水平。比较不同Durie-Salmon分期及治疗前后多发性骨髓瘤患者血清β_(2)-MG、TNF-α、LDH水平。比较治疗后不同疗效多发性骨髓瘤患者血清β_(2)-MG、TNF-α、LDH水平并进行相关性分析。结果:研究组血清β_(2)-MG、TNF-α、LDH水平明显高于对照组(均P<0.05)。Durie-Salmon分期Ⅲ期多发性骨髓瘤患者血清β_(2)-MG、TNF-α、LDH水平高于Ⅰ期和Ⅱ期,Ⅱ期患者这些指标又高于Ⅰ期(均P<0.05)。治疗后,多发性骨髓瘤患者血清β_(2)-MG、TNF-α、LDH水平较治疗前明显下降(均P<0.05)。不同疗效患者血清β_(2)-MG、TNF-α、LDH水平比较差异有统计学意义(均P<0.05)。多发性骨髓瘤患者血清β_(2)-MG、TNF-α、LDH水平与疗效正相关(r=0.862、0.396、0.885,均P<0.05)。结论:血清β_(2)-MG、TNF-α、LDH参与多发性骨髓瘤疾病发生与发展过程,对三者进行检测有助于评估疾病进展及疗效。

Edema, Enigma: 11 B-Hydroxysteroid Dehydrogenase Type 2 Inhibition by Sweetener “Stevia”

Intrduction: Edema, Hypertension and Hypokalemia occur with inhibition of 11 B-Hydroxysteroid Dehydrogenase Type 2 (11B-HSD2) by chronic Licorice ingestion. However, a similar presentation following a chronic use of another commonly used sweetener “Stevia” is not reported. Objective: To document a first case report of a subject presenting with Edema, Prehypertension and Hypokalemia induced by 11B-HSD2 inhibition induced by chronic ingestion of sweetener stevia. Case Report: 32 year old Caucasian woman presented with generalized edema (feet, hands and face) of over 6 months. She was noted to also manifest Prehypertension (138/88 mmHg) and Hypokalemia (3.4 mM/l). Laboratory tests revealed decline in serum aldosterone and plasma renin activity, an increase in plasma cortisol/cortisone ratio. On persistent interrogation, patient admitted to daily consumption of sweetener stevia for over 9 months. All the presenting manifestations resolved with normalization of the laboratory tests on withdrawal of stevia. Conclusion: This case report indicates that chronic ingestion of sweetener stevia may induce edema, hypertension and hypokalemia via reduced conversion of cortisol into cortisone by inhibition of 11 B-Hydroxysteroid Dehydrogenase Type 2.

Role of Cathepsin G in the Degradation of Glyceraldehyde-3-Phosphate Dehydrogenase Triggered by 4-Hydroxy-2-Nonenal in U937 Cells

Degradation of oxidized or oxidatively modified proteins is an essential part of the cellular antioxidant defense system. 4-Hydroxy-2-nonenal (HNE), a major reactive aldehyde formed by lipid peroxidation, causes many types of cellular damage. HNE-modified proteins are degraded by the ubiquitin-proteasome pathway or the lysosomal pathway. However, our previous studies using U937 cells showed that HNE-modified glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is degraded by cathepsin G. In the present study, we examined whether GAPDH in U937 cells treated with HNE in culture is degraded similarly to that incubated with HNE and U937 cell extract. Treatment with HNE for 10 min in culture decreased GAPDH activity in a concentration dependent manner, but did not affect GAPDH degradation. The proteasome activities were not affected by HNE, but culturing with HNE decreased cathepsin G activity and protein level in a concentration dependent manner. These results suggest that HNE-induced oxidative stress leads to decreased cathepsin G activity and results in the loss of GAPDH degradation. Taken together, our findings indicate that cathepsin G has an important role in the degradation of oxidatively modified GAPDH in U937 cells.

ADH1B与ALDH2在胃癌组织中的表达及其临床意义

目的探讨乙醇脱氢酶1B(alcohol dehydrogenase 1B,ADH1B)与乙醛脱氢酶2(aldehyde dehydrogenase 2,ALDH2)在胃癌组织中的表达及其临床意义。方法选取2017年05月至2019年10月期间在滁州市第一人民医院接受根治性切除的132例胃癌患者为研究对象,通过免疫组织化学染色(Immunohistochemistry,IHC)检测ADH1B与ALDH2在胃癌及癌旁组织中的表达。分析ADH1B、ALDH2表达与患者临床病理特征的关系,采用Kaplan-Meier曲线评估两者表达在胃癌中的预后价值。单、多变量Cox回归分析用于确定胃癌患者的独立预后因素。结果对132例组织样本的IHC分析显示ADH1B(41.5%vs 58.5%,χ^(2)=9.594,P=0.002)与ALDH2(38.8%vs 61.2%,χ^(2)=16.716,P<0.001)在胃癌组织中的阳性表达率显著低于其癌旁组织。与高表达组相比,ADH1B低表达在T_(3)-T_(4)期(χ^(2)=5.572,P=0.018)、pTNMⅢ期肿瘤(χ^(2)=4.675,P=0.031)中更为常见,淋巴血管侵犯率更高(χ^(2)=4.566,P=0.033)。ALDH2在低分化癌(χ^(2)=4.261,P=0.039)和pTNMⅢ期胃癌(χ^(2)=5.877,P=0.015)中表达更低,淋巴结转移率(χ^(2)=5.491,P=0.019)较高表达者更为频繁。生存分析表明ADH1B与ALDH2低表达是胃癌患者预后不良的标志。ADH1B低、高表达患者的3年总体生存(Overall survival,OS)率分别为52.3%和73.9%(χ^(2)=6.900,P=0.009),ALDH2低、高表达患者的3年OS率分别为49.8%和74.4%(χ^(2)=8.665,P=0.003)。ADH1B(HR=2.115,95%CI:1.133-3.946,P=0.019)与ALDH2低表达(HR=2.296,95%CI:1.207-4.367,P=0.011)是胃癌患者的独立预后因素。结论ADH1B与ALDH2在胃癌组织中呈明显低表达,两者可能是预测肿瘤进展与患者预后的分子标志物。

基于氧化应激介导NF-κB通路研究ALDH2基因表达对氯胺酮相关性膀胱炎的影响

目的:研究乙醛脱氢酶(ALDH2)基因表达对氧化应激介导的NF-κB通路在氯胺酮相关性膀胱炎(KIC)中的影响。方法:将SV-HUC-1细胞分为不同浓度氯胺酮组(0 mmol/L、0.5 mmol/L、1 mmol/L、2 mmol/L),诱导48 h后检测ALDH2蛋白表达量;然后将SV-HUC-1细胞构建分为对照组(si-NC组、OE-NC组)、ALDH2沉默组(si-ALDH2组)、ALDH2过表达组(OE-ALDH2组);分别用完全培养基和氯胺酮(1 mmol/L)诱导刺激细胞48 h,检测每组细胞内炎症因子和炎症蛋白水平。结果:蛋白质免疫印迹法(western blotting)显示经氯胺酮(0.5 mmol/L、1 mmol/L)处理后的ALDH2蛋白相对表达量显著高于0 mmol/L组(P<0.05);进一步在氯胺酮(1 mmol/L)诱导后的组中比较发现,si-ALDH2组炎症细胞因子白细胞介素-1β(IL-1β)及白细胞介素-6(IL-6)的表达较si-NC组显著增加(P<0.05);OE-ALDH2组IL-1β及IL-6的表达较OE-NC组显著减少(P<0.05);si-ALDH2组中炎症蛋白核因子-κB(NF-κB)、环氧合酶-2(COX-2)、诱导型一氧化氮合酶(iNOS)的表达量均较si-NC组升高(P<0.05);OE-ALDH2组中炎症蛋白NF-κB、COX-2、iNOS的表达量均较OE-NC组降低(P<0.05)。而在对照组(0 mmol/L)中,siALDH2组与si-NC组,OE-ALDH2组与OE-NC组比较,炎症因子和炎症蛋白水平比较均无统计学差异(P>0.05)。结论:ALDH2基因可在KIC的发生中发挥一定的抗炎保护作用。