Poliovirus induces indoleamine-2,3-dioxygenase and quinolinic acid synthesis in macaque brain.

Accumulation of the neurotoxin quinolinic acid within the brain occurs in a broad spectrum of patients with inflammatory neurologic disease and may be of neuropathologic significance. The production of quinolinic acid was postulated to reflect local induction of indoleamine 2,3-dioxygenase by cytokines in reactive cells and inflammatory cell infiltrates within the central nervous system. To test this hypothesis, macaques received an intraspinal injection of poliovirus as a model of localized inflammatory neurologic disease. Seventeen days later, spinal cord indoleamine 2,3-dioxygenase activity and quinolinic acid concentrations in spinal cord and cerebrospinal fluid were both increased in proportion to the degree of inflammatory responses and neurologic damage in the spinal cord, as well as the severity of motor paralysis. The absolute concentrations of quinolinic acid achieved in spinal cord and cerebrospinal fluid exceeded levels reported to kill spinal cord neurons in vitro. Smaller increases in indoleamine 2,3-dioxygenase activity and quinolinic acid concentrations also occurred in parietal cortex, a poliovirus target area. In frontal cortex, which is not a target for poliovirus, indoleamine 2,3-dioxygenase was not affected. A monoclonal antibody to human indoleamine 2,3-dioxygenase was used to visualize indoleamine 2,3-dioxygenase predominantly in grey matter of poliovirus-infected spinal cord, in conjunction with local inflammatory lesions. Macrophage/monocytes in vitro synthesized [13C6]quinolinic acid from [13C6]L-tryptophan, particularly when stimulated by interferon-gamma. Spinal cord slices from poliovirus-inoculated macaques in vitro also converted [13C6]L-tryptophan to [13C6]quinolinic acid. We conclude that local synthesis of quinolinic acid from L-tryptophan within the central nervous system follows the induction of indoleamine-2,3-dioxygenase, particularly within macrophage/microglia. In view of this link between immune stimulation and the synthesis of neurotoxic amounts of quinolinic acid, we propose that attenuation of local inflammation, strategies to reduce the synthesis of neuroactive kynurenine pathway metabolites, or drugs that interfere with the neurotoxicity of quinolinic acid offer new approaches to therapy in inflammatory neurologic disease.     

Indoleamine 2,3-dioxygenase activity and L-tryptophan transport in human breast cancer cells

The activity and expression of indoleamine 2,3-dioxygenase together with L-tryptophan transport has been examined in cultured human breast cancer cells. MDA-MB-231 but not MCF-7 cells expressed mRNA for indoleamine 2,3-dioxygenase. Kynurenine production by MDA-MB-231 cells, which was taken as a measure of enzyme activity, was markedly stimulated by interferon-gamma (1000 units/ml). Accordingly, L-tryptophan utilization by MDA-MB-231 cells was enhanced by interferon-gamma. 1-Methyl-DL-tryptophan (1 mM) inhibited interferon-gamma induced kynurenine production by MBA-MB-231 cells. Kynurenine production by MCF-7 cells remained at basal levels when cultured in the presence of interferon-gamma. L-Tryptophan transport into MDA-MB-231 cells was via a Na(+)-independent, BCH-sensitive pathway. It appears that system L (LAT1/CD98) may be the only pathway for l-tryptophan transport into these cells. 1-Methyl-D,L-tryptophan trans-stimulated l-tryptophan efflux from MDA-MB-231 cells and thus appears to be a transported substrate of system L. The results suggest that system L plays an important role in providing indoleamine-2,3-dioxygenase with its main substrate, L-tryptophan, and suggest a mechanism by which estrogen receptor-negative breast cancer cells may evade the attention of the immune system.     

Role of indoleamine-2,3-dioxygenase in alpha/beta and gamma interferon-mediated antiviral effects against herpes simplex virus infections

Gamma interferon (IFN-gamma)-mediated indoleamine-2,3-dioxygenase (IDO) activity in human astrocytoma cells and in native astrocytes was found to be responsible for the inhibition of herpes simplex virus replication. The effect is abolished in the presence of excess amounts of L-tryptophan. Both IFN-alpha and IFN-beta restricted herpes simplex virus replication in both cell types, but (in contrast to the results seen with IFN-gamma) the addition of an excess amount of L-tryptophan did not inhibit the induced antiviral effect.     

Circannual variation of efficacy outcomes in patients with newly diagnosed metastatic colorectal cancer and treated with first-line chemotherapy

Seasonal variation of baseline diagnosis (or clinical suspect) of stage I–III colorectal cancer patients has been repeatedly reported as an independent variable influencing overall survival. However, data are conflicting and no information is available about such a rhythm in advanced stage patients. To test whether a circannual rhythm of efficacy outcomes can be detected in this setting, we collected data about response rate (RR), progression-free survival (PFS), and overall survival (OS) to first-line chemotherapy of 1610 newly diagnosed metastatic patients treated at four independent centers. Responses to first-line chemotherapy were available for 1495 patients. A strong circannual rhythm in RR was evident, with the higher proportion of responding patients in the subgroup diagnosed in January (acrophase). At the time of data cutoff, 1322 patients progressed and 986 died, with median PFS and OS of 11 and 25.6 months, respectively. A circannual rhythmicity of the proportion of patients progressing at 6 months and surviving at 1 year was demonstrated, with acrophases located both in winter (February and January, respectively), similar to what reported for RR. Several interpretations about the genesis of this cyclic variation could be claimed: the rhythm in sunlight exposure and, as a consequence, of vitamin D serum levels and folate degradation, the variability in toxic effect intensity of chemotherapy, and the rhythm in the biological behavior of tumor cells. This observation is worth of further investigation both in preclinical and in clinical settings in order to better elucidate the underlying mechanisms.     

Tryptophan 2,3-dioxygenase activity in turkey poults infected with Bordetella avium

1. Liver tryptophan 2,3-dioxygenase (TPO) activity was depressed significantly by the Bordetella avium infection localized in the trachea of the turkey poult. 2. Tryptophan, given orally, induced a significant increase in TPO activity in both control and infected poults. 3. Hydrocortisone induced TPO activity in the turkey in a dose dependent manner.     

Cancer chemotherapy reduces plasma total polyphenols and total antioxidants capacity in colorectal cancer patients

Our aim was to investigate the effect of chemotherapy on plasma total antioxidant capacity and polyphenols in patients with colon cancer. Plasma samples were collected from 70 CRC patients under chemotherapy treatment, and 15 non-treated patients. The control group included 71 healthy individuals. Plasma ABTS and FRAP were measured as biomarkers of antioxidant total capacity and the total phenols as an indicator to determine the polyphenols levels in plasma. Treatment with chemotherapy protocols resulted in a significant decrease of ABTS (-24?%, p?相似文献   

结肠癌患者肠道菌群变化的临床研究

目的 对比分析结肠癌患者肠道菌群数量变化的特点,为结肠癌的治疗提供新途径。方法 选取2014年6月至2015年6月在本院就诊的结肠癌患者48例为试验组,同期在本院体检的48例健康者为对照组。取两组患者粪便标本进行传统菌落培养与计数检测,同时采用荧光定量聚合酶链反应（qPCR）法检测肠道细菌相对含量与相关基因表达拷贝数。结果 菌落计数结果显示试验组大肠埃希菌、屎肠球菌和酵母菌数量多于对照组,而双歧杆菌和乳酸杆菌数量少于对照组,组间比较差异均有统计学意义（P0.05）。结论 结肠癌患者大肠埃希菌、屎肠球菌和酵母菌数量明显增加,双歧杆菌和乳酸杆菌数量明显减少,肠道菌群数量变化在结肠癌的发生和发展中可能发挥一定作用。     

Inhibition of indoleamine 2,3-dioxygenase, an immunoregulatory target of the cancer suppression gene Bin1, potentiates cancer chemotherapy

Immune escape is a crucial feature of cancer progression about which little is known. Elevation of the immunomodulatory enzyme indoleamine 2,3-dioxygenase (IDO) in tumor cells can facilitate immune escape. Not known is how IDO becomes elevated or whether IDO inhibitors will be useful for cancer treatment. Here we show that IDO is under genetic control of Bin1, which is attenuated in many human malignancies. Mouse knockout studies indicate that Bin1 loss elevates the STAT1- and NF-kappaB-dependent expression of IDO, driving escape of oncogenically transformed cells from T cell-dependent antitumor immunity. In MMTV-Neu mice, an established breast cancer model, we show that small-molecule inhibitors of IDO cooperate with cytotoxic agents to elicit regression of established tumors refractory to single-agent therapy. Our findings suggest that Bin1 loss promotes immune escape in cancer by deregulating IDO and that IDO inhibitors may improve responses to cancer chemotherapy.     

Effects of nutritional support in patients with colorectal cancer during chemotherapy

Nutritional support, addressing the specific needs of this patient group, is required to help improve prognosis, and reduce the consequences of cancer-associated nutritional decline. Early intervention with nutritional supplementation has been shown to halt malnutrition, and may improve outcome in some patients. In our study we tried to assess the influence of nutritional support (counseling, oral liquids, megestrol acetate) on nutritional status and symptoms prevalence in patients with colorectal cancer during chemotherapy. Group I consisted of 215 (55%) patients with medium age 68 +/- 2.6 years who were monitored prospectively and were given nutritional support. Group II included 173 (45%) patients (medium age 67 +/- 2.9 years) without the proper nutritional counseling, in whom the data were collected retrospectively during a 6 years period of time. After evaluation Nottingham Screening Tool Score, Appetite Loss Scale and Karnofsky Performance Status) all patients in the group I received nutritional counseling, 153 of them (72%) were taking form of enteral food supplement and 103 (48%) patients were using megestrol acetate. Evaluating the initial risk measurements according to BMI, decrease in weight gain and NST, we did not find any significant difference between the two groups. After chemotherapy completion, patients in group I had a 15.3% drop of those who's BMI was < 20.65% patients increased their body weight, with an average weight gain of 1.5 kg (0.6-2.8 kg). Contrary, in group II we found increase in weight loss > or = 2 kg/month in 39% of patients. The appetite improvement was detected on Appetite Loss Scale from 3.1 (pre-chemotherapy) to 4.7 (post-chemotherapy) in group I, especially in those receiving megestrol acetate. In both groups Karnofsky Performance Status didn't change significantly reflecting the impact of the disease itself and chemotherapy procedures to the patient's condition. Nutritional counseling, supplemental feeding and pharmacological support do temporarily stop weight loss and improve appetite, social life and quality of life in those groups of patients. However, this improvement have no implications on patients KPS and course of their disease.     

The role of serine 167 in human indoleamine 2,3-dioxygenase: a comparison with tryptophan 2,3-dioxygenase

The initial step in the l-kynurenine pathway is oxidation of l-tryptophan to N-formylkynurenine and is catalyzed by one of two heme enzymes, tryptophan 2,3-dioxygenase (TDO) or indoleamine 2,3-dioxygenase (IDO). Here, we address the role of the conserved active site Ser167 residue in human IDO (S167A and S167H variants), which is replaced with a histidine in other mammalian and bacterial TDO enzymes. Our kinetic and spectroscopic data for S167A indicate that this residue is not essential for O 2 or substrate binding, and we propose that hydrogen bond stabilization of the catalytic ferrous-oxy complex involves active site water molecules in IDO. The data for S167H show that the ferrous-oxy complex is dramatically destabilized in this variant, which is similar to the behavior observed in human TDO [Basran et al. (2008) Biochemistry 47, 4752-4760], and that this destabilization essentially destroys catalytic activity. New kinetic data for the wild-type enzyme also identify the ternary [enzyme-O 2-substrate] complex. The data reveal significant differences between the IDO and TDO enzymes, and the implications of these results are discussed in terms of our current understanding of IDO and TDO catalysis.     

The role of plasma IDO activity as a diagnostic marker of patients with colorectal cancer

High levels of indoleamine 2,3-dioxygenase (IDO) are involved in tumour escape mechanisms. The aim of this study is the evaluation of l-kynurenine of plasma as marker of diagnostic and prognostic in patients with colorectal cancer. The study included 78 patients with colorectal cancer, of whom 15 % were in stage I/II, 30 % in stage III, and 55 % in stage IV, and was compared with a control group of 70 healthy subjects. The receiver operating characteristic (ROC) curve analysis showed an area under the curve of 0.917, with a specificity of 100 % and with a sensitivity to detect cancer of the colon of 85.2 %, taking 1.83 μM as a cut-off point. The overall survival analysis also indicated that patients with low levels of l-kynurenine in plasma increased survival rate after 45 months of follow-up (P = 0.032). These results show that the plasma levels of l-kynurenine could be a good biomarker to differentiate individuals with colorectal cancer from healthy individuals.     

Design,synthesis and biological evaluation of novel aryl-acrylic derivatives as novel indoleamine-2,3-dioxygenase 1 (IDO1) inhibitors

Two series of novel aryl-acrylic derivatives were designed, synthesized, and screened in enzymatic and cellular inhibitory activities. All compounds showed moderate to significant potency. The SAR analyses indicated that the semicarbazone linker is better than the 1,2,3-triazole linker. Among semicarbazone compounds that R₁ bearing di-chain amino groups exhibited superior activities to those with morpholino group. Furthermore, compounds with electron-withdrawing groups at the 2-position or 4-position on the terminal phenyl ring were more active. Among these, compounds 7g, 7i, 7m and 7n exhibited the inhibitory potency in the low micromolar range and displayed negligible level of cytotoxicity against normal HeLa cells. In addition, the study suggested that the aryl-acrylic is an interesting novel scaffold for IDO1 inhibition for further development.     

Comparative effects of oxygen on indoleamine 2,3-dioxygenase and tryptophan 2,3-dioxygenase of the kynurenine pathway

Indoleamine 2,3-dioxygenase (IDO) reacts with either oxygen or superoxide and tryptophan (trp) or other indoleamines while tryptophan 2,3-dioxygenase (TDO) reacts with oxygen and is specific for trp. These enzymes catalyze the rate-limiting step in the kynurenine (KYN) pathway from trp to quinolinic acid (QA) with TDO in kidney and liver and IDO in many tissues, including brain where it is low but inducible. QA, which does not cross the blood-brain barrier, is an excitotoxin found in the CNS during various pathologies and is associated with convulsions. We proposed that HBO-induced convulsions result from increased flux through the KYN pathway via oxygen stimulation of IDO. To test this, TDO and IDO of liver and brain, respectively, of Sprague Dawley rats were assayed with oxygen from 0 to 6.2 atm HBO. TDO activity was appreciable at even 30 microM oxygen and rose steeply to a maximum at 40 microM. Conversely, IDO had almost no detectable activity at or below 100 microM oxygen and maximum activity was not reached until about 1150 microM. (Plasma contains about 215 microM oxygen and capillaries about 20 microM oxygen when rats breathe air.) KYN was 60% higher in brains of HBO-convulsed rats compared to rats breathing air. While the oxygen concentration inside cells of rats breathing air or HBO is not known precisely, it is clear that the rate-limiting, IDO-catalyzed step in the brain KYN pathway (but not liver TDO) can be greatly accelerated in rats breathing HBO.     

Changes in plasma levels of inflammatory cytokines in response to paclitaxel chemotherapy

BACKGROUND: Flu-like symptoms are common, early transient side effects of paclitaxel chemotherapy. We hypothesized that these symptoms may be due to release of inflammatory cytokines in response to treatment. The objective of this study was to assess changes in plasma levels of interleukin (IL)-1beta, IL-6, IL-8, IL-10, IL-12, and TNF-alpha during chemotherapy and to correlate these changes with musculoskeletal symptoms. METHODS: Ninety patients with breast cancer were included; 70 patients received single agent paclitaxel either weekly or every 3 weeks and 20 received FAC (5-FU, doxorubicin, cyclophosphamide) chemotherapy. Fifteen healthy volunteers were included as controls. Cytokines and symptoms were measured before starting therapy, on day 3 and on the last day of one treatment cycle. RESULTS: At baseline, all subjects had measurable levels of IL-8 but only 49% had IL-12, 45% had IL-10, 32% had IL-6, and 21% had IL-1beta or TNF-alpha in their plasma. There was no difference in baseline cytokine levels between cancer patients and the healthy volunteers. Schedule-dependent transient changes in the levels of 3 cytokines were observed in the paclitaxel treated patients. In the every 3-week paclitaxel group, IL-6 and IL-8 increased whereas in the weekly paclitaxel group IL-10 increased significantly compared to baseline. Fatigue and flu-like symptoms were also worse on day 3. In the weekly paclitaxel group, increase in IL-10 level correlated positively with joint pain (p=0.003). In the every 3-week paclitaxel group, increase in IL-8 level correlated positively with flu-like symptom (p=0.008). In the FAC-treated group and among the healthy volunteers none of these cytokines increased significantly. CONCLUSIONS: Weekly paclitaxel induces transient increase in IL-10 levels whereas every 3-week higher dose treatments induce IL-8 and IL-6 in the plasma. These changes correlate with joint pain and flu-like symptoms.     

Indoleamine 2,3-dioxygenase pathways of pathogenic inflammation and immune escape in cancer

Genetic and pharmacological studies of indoleamine 2,3-dioxygenase (IDO) have established this tryptophan catabolic enzyme as a central driver of malignant development and progression. IDO acts in tumor, stromal and immune cells to support pathogenic inflammatory processes that engender immune tolerance to tumor antigens. The multifaceted effects of IDO activation in cancer include the suppression of T and NK cells, the generation and activation of T regulatory cells and myeloid-derived suppressor cells, and the promotion of tumor angiogenesis. Mechanistic investigations have defined the aryl hydrocarbon receptor, the master metabolic regulator mTORC1 and the stress kinase Gcn2 as key effector signaling elements for IDO, which also exerts a non-catalytic role in TGF-β signaling. Small-molecule inhibitors of IDO exhibit anticancer activity and cooperate with immunotherapy, radiotherapy or chemotherapy to trigger rapid regression of aggressive tumors otherwise resistant to treatment. Notably, the dramatic antitumor activity of certain targeted therapeutics such as imatinib (Gleevec) in gastrointestinal stromal tumors has been traced in part to IDO downregulation. Further, antitumor responses to immune checkpoint inhibitors can be heightened safely by a clinical lead inhibitor of the IDO pathway that relieves IDO-mediated suppression of mTORC1 in T cells. In this personal perspective on IDO as a nodal mediator of pathogenic inflammation and immune escape in cancer, we provide a conceptual foundation for the clinical development of IDO inhibitors as a novel class of immunomodulators with broad application in the treatment of advanced human cancer.     

盐霉素类似物的分离及抑制吲哚胺2,3-双加氧酶活性研究

为研究盐霉素发酵粗产物中的新型盐霉素类活性化合物。实验通过制备色谱从盐霉素发酵粗产物中分离得到两个盐霉素类似物,并利用波谱手段表征了这两个化合物的结构,化合物A为40-甲基盐霉素,化合物B为35-甲基盐霉素,均为新化合物。生物活性研究表明,化合物B具有一定的吲哚胺2,3-双加氧酶(IDO)抑制活性。