Near-Physiological Concentrations of Extracellular Pyruvate Stimulated Glucose Utilization along with Triglyceride Accumulation and Mitochondrial Activity in HepG2 Cells.

Pyruvate, a key intermediate in energy and nutrient metabolism, probably plays important roles in these regulations. In previous reports using cell lines, extracellular pyruvate of supraphysiological concentrations inhibited the glucose uptake by myotubes while being stimulated by adipocytes. As the effect of pyruvate on the glucose utilization is unclear in cultured hepatocytes. We have investigated the effects of extracellular pyruvate on the glucose utilization and the subsequent metabolic changes using the cell line HepG2. In a 24 h culture, pyruvate enhanced the glucose consumption more potently than 1 µM insulin, and this enhancement was detectable at a near-physiological concentrations of ≤1 mM. For metabolic changes following glucose consumption, the conversion ratio of glucose and pyruvate to extracellular lactate was approximately 1.0 without extracellular pyruvate. The addition of pyruvate decreased the conversion ratio to approximately 0.7, indicating that the glycolytic reaction switched from being an anaerobic to a partially aerobic feature. Consistent with this finding, pyruvate increased the accumulation of intracellular triglycerides which are produced through substrate supply from the mitochondria. Furthermore, pyruvate stimulated mitochondria activity as evidenced by increases in ATP content, mitochondrial DNA copy number, enhanced mitochondria-specific functional imaging and oxygen consumption. Interestingly, 1 mM pyruvate increased oxygen consumption immediately after addition. In this study, we found that near-physiological concentrations of extracellular pyruvate exerted various changes in metabolic events, including glucose influx, lactate conversion rations, TG accumulation, and mitochondrial activity in HepG2 cells.

Application to Butterbur Products of a Suggested Daily Intake-Based Safety Evaluation of Individual Herbal Supplements with Cytochrome P450 Expression as a Major Index.

The present paper first proposes a method for ensuring the safety of commercial herbal supplements, termed the suggested daily intake-based safety evaluation (SDI-based safety evaluation). This new method was inspired as a backward analog of the acceptable daily intake (ADI) derivation from the no observed adverse effect level (NOAEL), the basis of food additive risk analysis; namely, rats are dosed with individual herbal supplement products at the SDI for human use multiplied by 100 (the usual uncertainty factor value) per body weight for 8 d. The primary endpoint is the sign of adverse effects on liver, especially gene expression of cytochrome P450 (CYP) isoforms. The proposed method was then applied to three butterbur (Petasites hybridus) products without pyrrolizidine alkaloids but lacking clear safety information. Results showed that two oily products markedly enhanced the mRNA expression of CYP2B (>10-fold) and moderately enhanced that of CYP3A1 (<4-fold) with liver enlargement. These products also caused the renal accumulation of alpha 2-microglobulin. One powdery product showed no significant effect on liver and kidney. The large difference in effects of products was due to the difference in chemical composition revealed by liquid chromatography-mass spectroscopy. The oily and the powdery products required attention in terms of safety and effectiveness, respectively. Finally, the results from the SDI-based safety evaluation of butterbur and other herbal supplement products were grouped into four categories and cautionary notes were discussed. The SDI-based safety evaluation of their products by herbal supplement operators would contribute to safe and secure use by consumers.

[Association of D-dimer Levels with Complications after Subcutaneous Implantable Central Venous Port Placement in Combination Chemotherapy with Bevacizumab for Colorectal Cancer].

Bevacizumab(BV)combination chemotherapy in colorectal cancer under subcutaneously implanted central venous port (CVP)implantation may cause complications after the implantation. Measurement of D-dimer is recommended to predict thromboembolism and other complications, but its relevance to complications after CVP implantation remains unclear. In this study, we investigated the association between D-dimer and complications after CVP implantation in 93 patients with colorectal cancer who received BV combination chemotherapy. Complications after CVP implantation occurred in 26 patients (28%), and those with VTE showed higher D-dimer values at the onset of the complication. The D-dimer values of the patients with VTE displayed a sharp increase at the onset of the disease, while those with an abnormal CVP implantation site showed a more variable course. Measurement of D-dimer levels appeared useful in estimating the incidence of VTE and abnormal CVP implantation sites in post-CVP implantation complications of BV combination chemotherapy for colorectal cancer. Further, monitoring not only the quantitative values but also the fluctuations over time is also important.

[Exploratory Study of the Risk Factors for Acute Kidney Injury in the Cisplatin Combination Chemotherapy for Solid Cancer].

In the present study, we investigated the rate of cisplatin(CDDP)-induced acute kidney injury(CIA)and examined its association with various clinical factors in the combination therapy with CDDP for solid cancers. A total of 726 cases of solid cancer that had been indicated for the CDDP combination regimen from December 2012 to December 2013 were enrolled. CIA occurred in 48 cases(6.6%). The multivariate analysis revealed that diabetes, the regular use of non-steroidal anti- inflammatory drugs(NSAIDs), first dose of CDDP, and severe hyponatremia(≥Grade 3)within one week after CDDP administration were significantly associated with an increased risk for CIA, whereas magnesium supplementation was associated with a significantly reduced risk for CIA. Particularly, diabetes and cardiovascular disease were identified as risk factors for CIA in patients with esophageal and head and neck cancers. Based on the results of this survey, it is important to formulate preventive measures, evaluate risk factors, and respond rapidly.

[Risk Factors of Thromboembolism in Colorectal Cancer Patients Receiving Combination Chemotherapy with Bevacizumab].

We investigated the incidence of thromboembolism in patients receiving combination chemotherapy with bevacizumab (BV)for colorectal cancer and examined its association with clinical factors. Between July 2007 and April 2014, 250 patients with colorectal cancer received combination chemotherapy with BV. Thromboembolism occurred in 24 cases(9.6%). Five predictive risk factors(platelet count B350,000/µL, hemoglobin <10 g/dL, leukocyte count>11,000/mL, body mass index B25.3 kg/m2, and D-dimer B1.44 µg/mL)were set based on a previous report, and the corresponding number of risk factors for thromboembolism and incidence of thromboembolism were examined. The results of multivariate analysis showed that the occurrence of 3 or more risk factors conferred a significant risk for the incidence of thromboembolism. Due to the increased risk of developing thromboembolism in such patients, special attention during management is required.

[Survey of Cholinergic Symptoms in Patients with Colorectal Cancer Who Were Receiving Irinotecan Hydrochloride Combination Chemotherapy].

We investigated the incidence of cholinergic symptoms related to irinotecan hydrochloride(CPT-11)and examined their association with clinical factors. The subjects were 61 patients with colorectal cancer for whom combination chemotherapy with CPT-11 was indicated between May 2008 and December 2014. The incidence of CPT-11-related cholinergic symptoms was investigated. Cholinergic symptoms were observed in 46 patients(75.4%), of whom 29(47.5%)showed Grade 2 or higher symptoms as follows: nasal discharge(47.5%), lacrimation(39.3%), nausea/vomiting(29.5%), and watery stool (26.2%). The results of the multivariate analysis showed that high-dose CPT-11 administration(150mg/m2)was a significant risk factor for the appearance of cholinergic symptoms and that PS 0 was a significant factor for reducing the onset of symptoms. It is important to adequately manage cholinergic symptoms, considering these clinical factors.

[Associations between Clinical Factors and Acute Renal Failure Due to Cisplatin Combination Chemotherapy for Lung Cancer].

In this study, we investigated the clinical factors associated with acute kidney injury (AKI) due to combination therapy with cisplatin (CDDP) for treating lung cancer. We classified cases according to the presence or absence of adequate hydration and magnesium(Mg)administered above the regulations of the registered regimen to evaluate the effect due to differences in hydration on AKI. We also investigated clinical factors before and after administration of CDDP in each case group, and examined their association with AKI. Seventy-four patients with lung cancer that were indicated for treatment with a CDDP combination regimen between December 2012 and April 2013 were studied. The patients whose conditions progressed to AKI of Bgrade 2 accounted for 0% (0/33) in the Mg administration group and 7.3%(3/41)in the Mg non-administration group. In particular, 2 cases of serious AKI (grade 4) were observed in the Mg non-administration without additional hydration group. When compared with other groups, a high antiemetic rate and favorable urine volume were observed in the Mg administration with additional hydration group. In the patients with AKI, many developed hyponatremia of Bgrade 3 within 1 week after administration of CDDP. Although Mg administration and ample hydration seem to be effective measures to deal with CDDP-caused AKI, comprehensive monitoring, including antiemesis therapy, after CDDP administration and correction of electrolytes is important.

Production of L-tryptophan-derived catabolites in hepatocytes from streptozotocin-induced diabetic rats.

BACKGROUND: Recently the L-tryptophan (Trp) metabolites such as L-kynurenine(Kyn), L-kinurenic acid, quinolinic acid (QA) and picolinic acid (PA) have been shown physiologically important in central nervous and immune system, and various enzyme activities concerning their production were reported to be affected by insulin-dependent diabetes mellitus. However, the states of these metabolites in diabetes have not been clarified enough yet. AIM OF STUDY: The present study was performed to make clear the states of the productions of L-Kyn, QA, PA and nicotinamide (Nam) in vitro in the hepatocytes prepared from streptozotocin (STZ)-induced diabetic rats using [5-3H]L-Trp. METHODS: The diabetic model rats were made by STZ injection (60 mg/kg) and the hepatocytes isolated from the rats were incubated with [5-3H]L-Trp. The amounts of metabolites derived from L-Trp were determined by the isotope-dilution methods. RESULTS: The alpha-amino-beta-carboxymuconate-epsilon-semiarldehyde decarboxylase (ACMSD) mRNA level in the diabetic group was greatly higher than that in the control group. In the STZ-induced diabetes group, the amount of [5-3H]L-Trp converted to tritiated water, L-Kyn or QA were found to be more than 3 times of that in the control group, respectively. The produced amounts of PA and Nam were not significantly different between the diabetic and the control groups. CONCLUSIONS: It is suggested that STZ-diabetes mellitus causes augmentations of both L-Kyn and QA generations but not those of PA and Nam in liver, indicating the possibility that the immune and neuronal systems of insulin dependent diabetes mellitus would be influenced by the increased amounts of LKyn and QA but not by those of PA and Nam.

Down-regulation of alpha-amino-beta-carboxymuconate-epsilon-semialdehyde decarboxylase by polyunsaturated fatty acids in hepatocytes is not mediated by PPARalpha.

BACKGROUND: alpha-Amino-beta-carboxymuconate-epsilon-semialdehyde decarboxylase (ACMSD) is a key enzyme in NAD biosynthesis from tryptophan. Dietary polyunsaturated fatty acids (PUFA) have been shown to suppress hepatic ACMSD activity and its mRNA level in rat. However the mechanism of the suppressive action has not been clarified yet. Although the phenomena that fatty acids suppress the expression of ACMSD in rat liver have been established in vivo experiment, it is still obscure whether the effect of fatty acids on the expression of the enzyme is caused by its direct or indirect action, because there have been very few investigations performed in vitro. AIM OF THE STUDY: In this study, to examine whether down-regulation of ACMSD mRNA by PUFA involves peroxisome proliferator-activated receptor (PPAR) alpha mediated mechanism or not, we investigated the effect of PUFA on the ACMSD expression by using primary cultured rat hepatocytes. METHODS: For this purpose we investigated the effect of PUFA (linoleic acid and eicosapentanoic acid) on the ACMSD mRNA level in primary-cultured rat hepatocytes and compared its effect with that of WY-14,643 (a PPARalpha agonist). After the incubation of hepatocytes with fatty acids, WY-14,643 and/or MK886 (a PPARalpha antagonist), mRNA levels of ACMSD and a peroxisome marker enzyme acyl-CoA oxidase (ACO) were determined by competitive reverse transcription-polymerase chain reaction (RT-PCR) method. RESULTS: ACMSD mRNA level in primary hepatocytes were decreased by the incubation with high concentrations of linoleic acid, eicosapentaenoic acid (EPA) and WY-14,643. The appearance of ACO mRNA by WY-14,643 was remarkably increased, and those by linoleic acid and EPA were increased less than that by WY-14,643. Moreover, the suppression of ACMSD mRNA and the augmentation of ACO mRNA by WY-14,643 were inhibited by MK886, but the suppression by PUFA was not substantially affected by MK886. CONCLUSIONS: The present study suggesting that the mechanism of decrease in ACMSD mRNA level by PUFA was different from that by WY-14,643, and that there would be any pathway other than PPARalpha mediated one for PUFA to regulate ACMSD expression.