Degradation of indole via a two-component indole oxygenase system from Enterococcus hirae GDIAS-5.

Animal farming copiously generates indoles, which contribute to odor and pose a challenge for deodorization. While biodegradation is widely accepted, there is a lack of suitable indole-degrading bacteria for animal husbandry. In this study, we aimed to construct genetically engineered strains with indole-degrading abilities. Enterococcus hirae GDIAS-5 is a highly efficient indole-degrading bacterium, which functions via a monooxygenase YcnE presumably contributes to indole oxidation. However, the efficiency of engineered Escherichia coli expressing YcnE for indole degradation is lower than that of GDIAS-5. To improve its efficacy, the underlying indole-degradation mechanisms in GDIAS-5 were analyzed. An ido operon that responds to a two-component indole oxygenase system was identified. In vitro experiments showed that the reductase component of YcnE, YdgI, can improve the catalytic efficiency. The reconstruction of the two-component system in E. coli exhibited higher indole removal efficiency than GDIAS-5. Furthermore, isatin, the key intermediate metabolite in indole degradation, might be degraded via a novel isatin-acetaminophen-aminophenol pathway involving an amidase whose coding gene is located near the ido operon. The two-component anaerobic oxidation system, upstream degradation pathway, and engineering strains investigated in this study provide important insights into indole degradation metabolism and offer efficient resources for achieving bacterial odor elimination.

Substance basis of warm nature of Poria cocos.

Objective: The research indicated that the nature of Chinese medicine is mainly related to body's substance and energy metabolism. The purpose of the study is to elucidate the substance basis for warm nature of Poria cocos (called Fuling (FL) in Chinese). Methods: In terms of the effects of its separated fractions on the substance and energy metabolism in rat models of cold-deficiency with Aconiti Lateralis Radix Praeparata (called Fuzi (FZ) in Chinese), with hot nature, as reference drug. Biochemical indexes in the material metabolism, energy metabolism, endocrine system, nervous system and nucleotide system were determined, then analyzed by additive, cluster and principal component analysis (PCA). Results: The medicinal natures of oligosaccharides and amino acids fractions were attributable to plain and crude polysaccharides, volatile oils and triterpenoids fractions were attributable to mild warm. Conclusion: The nature of FL was regarded as mild warm based on the old records of Chinese medicine and fractions of crude polysaccharides, volatile oils and triterpenoids might be the main substance basis for the warm nature of FL. It is the first time that substance basis of FL was elucidated from view point of medicinal nature.

Regulatory effects of Poria on substance and energy metabolism in cold-deficiency syndrome compared with heat-deficiency syndrome in rats.

Recent studies have revealed that the property of drug is mainly associated with the body's substance and energy metabolism. The present study aimed to evaluate the drug property of Poria, called Fuling (FL) in traditional Chinese medicine (TCM), in terms of its effects on the substance and energy metabolism in rat models of cold-deficiency and heat-deficiency syndromes, compared with Aconiti Lateralis Radix Praeparaia, called Fuzi (FZ) in TCM, with hot property, and Anemarrhenae Rhizoma, called Zhimu (ZM) in TCM, with cold property, as reference drugs, respectively. The appearance score, toe and rectal temperatures of the animals treated were assessed at different time points. Several indices in vivo correlated with substance and energy metabolism (glucokinas, phosphoglycerate kinase, cytochrome c reductase, cytochrome c oxydase, and Na+-K+-ATPase), endocrine system (triiodothyronine, thyroxine, and 17-hydroxycorticosteroid), nervous system (acetylcholin esterase), and cyclic nucleotide system were determined. The changes in appearance score and indices in vivo suggested the successful establishment of cold-deficiency and heat-deficiency syndrome models. FZ reversed the decreased levels of indices (substance and energy metabolism and endocrine system) and alleviated the syndrome of cold-deficiency model, and ZM showed obviously therapeutic effect on heat-deficiency syndrome (appearance score, substance and energy metabolism, and endocrine system). FL could alleviate cold-deficiency syndrome and raise the decreased levels of glucokinas, phosphoglycerate kinase, cytochrome c reductase and triiodothyronine in cold-deficiency model, but had no significant effect on heat-deficiency syndrome. Drug property of FL was inferred as trending to "flat and warm", which still need further study. It was advisable to adopt both cold-deficiency and heat-deficiency models to study the drugs with "flat" property.

GOLDEN2-LIKE transcription factors coordinate the tolerance to Cucumber mosaic virus in Arabidopsis.

Arabidopsis thaliana GOLDEN2-LIKE (GLKs) transcription factors play important roles in regulation of photosynthesis-associated nuclear genes, as well as participate in chloroplast development. However, the involvement of GLKs in plants resistance to virus remains largely unknown. Here, the relationship between GLKs and Cucumber mosaic virus (CMV) stress response was investigated. Our results showed that the Arabidopsis glk1glk2 double-mutant was more susceptible to CMV infection and suffered more serious damages (such as higher oxidative damages, more compromised in PSII photochemistry and more reactive oxygen species accumulation) when compared with the wild-type plants. Interestingly, there was little difference between single mutant (glk1 or glk2) and wild-type plants in response to CMV infection, suggesting GLK1 and GLK2 might function redundant in virus resistance in Arabidopsis. Furthermore, the induction of antioxidant system and defense-associated genes expression in the double mutant were inhibited when compared with single mutant or wild-type plants after CMV infection. Further evidences showed that salicylic acid (SA) and jasmonic acid (JA) might be involved in GLKs-mediated virus resistance, as SA or JA level and synthesis-related genes transcription were impaired in glk1glk2 mutant. Taken together, our results indicated that GLKs played a positively role in virus resistance in Arabidopsis.

Role of Transcription Factor HAT1 in Modulating Arabidopsis thaliana Response to Cucumber mosaic virus.

Arabidopsis thaliana homeodomain-leucine zipper protein 1 (HAT1) belongs to the homeodomain-leucine zipper (HD-Zip) family class II that plays important roles in plant growth and development as a transcription factor. To elucidate further the role of HD-Zip II transcription factors in plant defense, the A. thaliana hat1, hat1hat3 and hat1hat2hat3 mutants and HAT1 overexpression plants (HAT1OX) were challenged with Cucumber mosaic virus (CMV). HAT1OX displayed more susceptibility, while loss-of-function mutants of HAT1 exhibited less susceptibility to CMV infection. HAT1 and its close homologs HAT2 and HAT3 function redundantly, as the triple mutant hat1hat2hat3 displayed increased virus resistance compared with the hat1 and hat1hat3 mutants. Furthermore, the induction of the antioxidant system (the activities and expression of enzymatic antioxidants) and the expression of defense-associated genes were down-regulated in HAT1OX but up-regulated in hat1hat2hat3 when compared with Col-0 after CMV infection. Further evidence showed that the involvement of HAT1 in the anti-CMV defense response might be dependent on salicylic acid (SA) but not jasmonic acid (JA). The SA level or expression of SA synthesis-related genes was decreased in HAT1OX but increased in hat1hat2hat3 compared with Col-0 after CMV infection, but there were little difference in JA level or JA synthesis-related gene expression among HAT1OX or defective plants. In addition, HAT1 expression is dependent on SA accumulation. Taken together, our study indicated that HAT1 negatively regulates plant defense responses to CMV.

Orchestration of hydrogen peroxide and nitric oxide in brassinosteroid-mediated systemic virus resistance in Nicotiana benthamiana.

Brassinosteroids (BRs) play essential roles in modulating plant growth, development and stress responses. Here, involvement of BRs in plant systemic resistance to virus was studied. Treatment of local leaves in Nicotiana benthamiana with BRs induced virus resistance in upper untreated leaves, accompanied by accumulations of H2O2 and NO. Scavenging of H2O2 or NO in upper leaves blocked BR-induced systemic virus resistance. BR-induced systemic H2O2 accumulation was blocked by local pharmacological inhibition of NADPH oxidase or silencing of respiratory burst oxidase homolog gene NbRBOHB, but not by systemic NADPH oxidase inhibition or NbRBOHA silencing. Silencing of the nitrite-dependent nitrate reductase gene NbNR or systemic pharmacological inhibition of NR compromised BR-triggered systemic NO accumulation, while local inhibition of NR, silencing of NbNOA1 and inhibition of NOS had little effect. Moreover, we provide evidence that BR-activated H2O2 is required for NO synthesis. Pharmacological scavenging or genetic inhibiting of H2O2 generation blocked BR-induced systemic NO production, but BR-induced H2O2 production was not sensitive to NO scavengers or silencing of NbNR. Systemically applied sodium nitroprusside rescued BR-induced systemic virus defense in NbRBOHB-silenced plants, but H2O2 did not reverse the effect of NbNR silencing on BR-induced systemic virus resistance. Finally, we demonstrate that the receptor kinase BRI1(BR insensitive 1) is an upstream component in BR-mediated systemic defense signaling, as silencing of NbBRI1 compromised the BR-induced H2O2 and NO production associated with systemic virus resistance. Together, our pharmacological and genetic data suggest the existence of a signaling pathway leading to BR-mediated systemic virus resistance that involves local Respiratory Burst Oxidase Homolog B (RBOHB)-dependent H2O2 production and subsequent systemic NR-dependent NO generation.

Nitric oxide is involved in brassinosteroid-induced alternative respiratory pathway in Nicotiana benthamiana seedlings' response to salt stress.

Recent studies reported that brassinosteroids (BRs) can induce plant tolerance to different environmental stresses via the nitric oxide (NO) signaling pathway. Previous reports have indicated that alternative oxidase (AOX) plays an important role in plants under various stresses. The mechanisms governing how NO is involved as a signal molecule which connects BR with AOX in regulating stress tolerance are still unknown. Recently, we found that Nicotiana benthamiana seedlings which were pretreated with BR have more tolerance to salt stress, accompanied with an increase of CN-resistant respiration. Our results suggested that pretreatment with 0.1 µM brassinolide (BL, the most active brassinosteroid) alleviated salt-induced oxidative damage and increased the NbAOX1 transcript level. Application of 2-(4-carboxyphenyl)-4,4,5,5-tetramethyl-imidazoline-1-1-oxyl-3-oxide (cPTIO, an NO scavenger) or virus-induced gene silencing of nitrate reductase (NR) and nitric oxide synthase (NOS)-like enzyme compromised the BRs-induced alternative respiratory pathway. Furthermore, pretreatment with specific chemical inhibitors of NR and NOS or gene silencing experiments decreased plant resistance to salt stress which also compromised BRs-induced salt stress tolerance. In conclusion, NO is involved in BRs-induced AOX capability which plays essential roles in salt tolerance in N. benthamiana seedlings.

[Determination of plasma protein binding rate of arctiin and arctigenin with ultrafiltration].

OBJECTIVE: To determine the plasma protein binding rate of arctiin and arctigenin. METHOD: The ultrafiltration combined with HPLC was employed to determine the plasma protein binding rate of arctiin and arctigenin as well as rat plasma and healthy human plasma proteins. RESULT: The plasma protein binding rate of arctiin with rat plasma at the concentrations of 64. 29, 32.14, 16.07 mg x L(-1) were (71.2 +/- 2.0)%, (73.4 +/- 0.61)%, (78.2 +/- 1.9)%, respectively; while the plasma protein binding rate of arctiin with healthy human plasma at the above concentrations were (64.8 +/- 3.1)%, (64.5 +/- 2.5)%, (77.5 +/- 1.7)%, respectively. The plasma protein binding rate of arctigenin with rat plasma at the concentrations of 77.42, 38.71, 19.36 mg x L(-1) were (96.7 +/- 0.41)%, (96.8 +/- 1.6)%, (97.3 +/- 0.46)%, respectively; while the plasma protein binding rate of arctigenin with normal human plasma at the above concentrations were (94.7 +/- 3.1)%, (96.8 +/- 1.6)%, (97.9 +/- 1.3)%, respectively. CONCLUSION: The binding rate of arctiin with rat plasma protein was moderate, which is slightly higher than the binding rate of arctiin with healthy human plasma protein. The plasma protein binding rates of arctigenin with both rat plasma and healthy human plasma are very high.

Simultaneous determination of arctiin and its metabolites in rat urine and feces by HPLC.

Arctiin, an important lignan compound in Fructus Arctii, has been reported to possess various kinds of bioactivities. Previous studies on the pharmacokinetic of arctiin after oral administration showed that it had a rapid absorption phase followed by a sharp but lasting disappearance. To gain deep insight into the action mechanism of arctiin, the excretion and metabolism of arctiin in vivo should be further studied. In this paper, three metabolites were isolated and identified in rat feces as (-)-enterolactone (M-1), (-)-arctigenin (M-2) and [(2R,3R)-2-(3'-hydroxybenzyl)-3-(3″,4″-dimethoxybenzyl)-butyrolactone] (M-3). Based on the structures of three metabolites, possible metabolic pathways of arctiin in rats are proposed. At the same time, the cumulative excretion rate of arctiin and its metabolites in rat urine and feces were determined, indicating that arctiin was excreted 19.84% in urine and 1.80% in feces, respectively, enterolactone, the most main metabolite, was excreted 35.80% in feces. These results provide very important information for understanding the metabolism and excretion of arctiin in vivo and speculating its action mechanism, they can provide useful information and reference for further metabolic investigations on arctiin in humans.

MUTYH association with esophageal adenocarcinoma in a Han Chinese population.

Adenocarcinoma of esophagus (AE) is a complex disease, affected by a variety of genetic and environmental factors. Much evidence has shown that the MutY glycosylase homologue (MUTYH) plays a key role in the pathogenesis of many cancers. However, there have been no reports on influence on AE in the Han Chinese population. The objective of this study was to investigate this issue. A gene-based association study was conducted using three single nucleotide polymorphisms(SNPs) reported in previous studies. The three SNPs (rs3219463, rs3219472, rs3219489) were genotyped in 207 unrelated AE patients and 249 healthy controls in a case-control study using polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). The results revealed that the genotype distribution of rs3219472 differed between the case and control groups (OR=1.66,95%CI=1.11-2.48, P=0.012 ), indicating that an association may exist between MUTYH and AE. These findings support a signifcant role for MUTYH in AE pathogenesis in the Han Chinese population.

[Recovery of reproductive endocrine function after orthotopic fetal ovarian allotransplantation in rats].

OBJECTIVE: To assess the recovery of the reproductive endocrine function in rats following orthotopic transplantation of fetal ovarian allograft. METHODS: Ninety female SD rats (50-60 days old) were randomized into graft recipient group (n=50), positive control group (n=20), and negative control group (n=20) to receive orthotopic transplantation of fetal (17-19 gestational days) ovaries following bilateral oophorectomy, sham abdominal surgery, and bilateral oophorectomy, respectively. At 45 days after the surgeries, serum estradiol and progesterone levels were measured and the ovaries were removed for evaluation of the ovarian volume and follicle development. RESULTS: On day 45 after the operations, the estradiol or progesterone levels showed no significant difference between the recipient group and positive control group (P>0.05), but both were significantly lowered in the negative control group (P<0.05). The ovarian volume was comparable between the recipient group and positive control group (P>0.05), and optical microscopy showed follicles in different stages of development and formation of corpus luteum in the ovaries in both groups. CONCLUSION: Fetal rat ovary allografts can develop into functional ovaries capable of ovulation to restore the reproductive endocrine function of recipient female rats.

[In vitro stimulation of retinoic acid syndrome by rotary cell culture system and its relationship with expression of CXCR4 and SDF-1 alpha].

OBJECTIVE: To explore the molecular mechanism and prevention of retinoic acid syndrome (RAS). METHODS: SDF-1 alpha mRNA from healthy adult lung tissue was measured by RT-PCR, CXCR4 protein expression on the cell membrane of APL cells induced by ATRA (APL-ATRA) was tested by FCM, and the rotary cell culture system (RCCS) was used to build a modal for in vitro stimulation of APL-ATRA infiltrating human lung tissue. The ability of APL-ATRA in adhesion, migration and infiltration was observed by interference from DEX, Ara-C and DNR. RESULTS: The APL-ATRA cells could evidently infiltrate into normal lung tissue. Mean fluorescence intensity (MFI) of CXCR4 on the cell membrane of APL-ATRA cells was 30.6 +/- 1.8, which was much higher than that on unspecialized APL cells (9.8 +/- 4.2). SDF-1 alpha mRNA expression was detected positive in all 6 lung tissue. Contrary to the control groups, DEX could dramatically restrain the ability of APL-ATRA cells in adhesion and migration [(27.2 +/- 2.6)% vs. (46.0 +/- 3.0)%, (28.1 +/- 4.0)% vs. (48.2 +/- 3.0)%], while Ara-C and DNR could distinctly depress the ability in adhesion, migration and infiltration [(28.1 +/- 3.0)%, (30.2 +/- 3.2)% vs. (46.0 +/- 3.0)%; (29.0 +/- 4.0)%, (23.0 +/- 5.2)% vs. (48.2 +/- 3.0)%; (16.8 +/- 7.6)%, (17.1 +/- 6.0)% vs. (43.6 +/- 5.0)%]. CONCLUSION: In vitro APL-ATRA cells can infiltrate into the human lung tissue. High expression of CXCR4 on APL-ATRA and SDF-1 alpha in the lung tissue may be one of the molecular mechanisms of the lung infiltration and RAS. DEX, Ara-C and DNR can dramatically restrain the ability of APL-ATRA cells in adhesion, migration and infiltration.

[Adverse effects of intravenous arsenic trioxide and their prevention].

OBJECTIVE: To study the main side effects of As(2)O(3) and the way of prevention. METHODS: The changes of body weight and various systems of body were observed after treatment with As(2)O(3) injection. The arsenic content in blood, urine and hair was detected with atom absorbed-spectrum analysis. RESULTS: Mild reactions were observed in 57.43% (147/256) of the patients and they could subside after cessation of arsenic treatment or allotherapy. Chronic mild poisoning manifestations including arsenic furuncle, liver dysfunction and peripheral nerve injury were found in 2.73% (7/256) of the patients and they subsided gradually after treatment. Chronic severe poisoning was found in 1.17% of the patients and all of them died of liver failure. As(2)O(3) might cause decrease of peripheral blood WBC in catabatic patients. There was no infection after allopathy without ceasing arsenic medication. The results showed that As(2)O(3) could distribute over and discharge from the plasma without accumulation in blood. The results also demonstrated the main route of excretion for As(2)O(3) is through urine and there is definite accumulation in the hair 50 days after treatment. CONCLUSION: Most of the side effects of As(2)O(3) are mild and recoverable. Allotherapy could be effective to relieve the complications without stopping arsenic medication. A few patients with complicating hepatitis may suffer from chronic poisoning. As(2)O(3) may cause increase of peripheral blood WBC in induced catabatic APL patients. The side effects must be prevented early.

[Correlation of thrombosis with increased platelet turnover in essential thrombocythemia].

This study was aimed to investigate the correlation of thrombosis with increased platelet turnover in essential thrombocythemia. According to presence or absence of thrombosis, 26 patients with ET were divided into two groups. Reticulated platelets (RP) were measured by flow cytometry and 26 healthy volunteers were selected as healthy controls. The ET patients with thrombosis were treated with hydroxyurea and interferon-alpha. The results demonstrated that the ET patients with thrombotic events had a significantly higher RP percentage (14.8% +/- 7.2%) than that in both asymptomatic ET patients (4.5% +/- 2.3%) and normal control (3.3% +/- 1.5%), (P < 0.05); the RP percentage in asymptomatic ET patients did not differ significantly from controls. ET patients with thrombosis also had a significantly higher absolute RP (ARP) count than those in ET patients without thrombosis [(176 +/- 37) x 10(9)/L vs (46 +/- 12) x 10(9)/L]. The ET patients with thrombosis were successfully treated with hydroxyurea plus INF-alpha, the RP percentage and ARP counts obviously reduced. In conclusion, when the ET patients had thrombotic events, those patients had a significantly higher RP percentage and ARP compared with patients without thrombosis and healthy controls. The ET patients with thrombosis were successfully treated with hydroxyurea plus INF-alpha.