Effect of Hydration with Bicarbonate Ringer's Solution on Cisplatin-Induced Acute Kidney Injury in Patients with Esophageal Cancer: A Retrospective Cohort Study.

INTRODUCTION: Cisplatin (CDDP) often causes acute kidney injury (AKI), and magnesium supplementation has been suggested to be important in preventing CDDP-induced AKI. Sodium bicarbonate Ringer's solution (BRS) is a crystalloid solution composed of various electrolytes, including Mg2+, and can be generally used to supplement missing extracellular fluid and correct metabolic acidosis; however, the clinical outcomes of hydration with BRS for CDDP-induced AKI remain unclear. In this study, we retrospectively compared the effects of BRS and normal saline for hydration in patients undergoing CDDP treatment. METHODS: We analyzed the incidence rate of AKI (grade ≥ 1), the severity of AKI, the serum magnesium level, and the incidence rate of grade ≥ 3 hematological toxicities (leukopenia, neutropenia, anemia, or thrombocytopenia) following CDDP and fluorouracil (5-FU) administration in 131 in-patients who received CDDP and 5-FU for the first time to treat esophageal cancer. RESULTS: Fifty-six patients (43%) received saline alone, while 75 patients (57%) received BRS for hydration. The incidence rate of AKI (grade ≥ 1) was significantly lower in the BRS group (11%) than that in the saline group (39%, p < 0.001). Moreover, severe AKI (grade ≥ 2) was significantly less common in the BRS group than in the saline group. Although the serum magnesium levels before CDDP administration were not significantly different between the two groups (p = 0.939), the serum magnesium levels on days 2-3 after CDDP administration in the BRS group were significantly higher than those in the saline group (p < 0.001). In contrast, there were no significant differences in the incidence rates of hematological toxicity between the two groups. Multivariate analysis revealed that BRS use was an independent factor that significantly contributed to AKI prevention (odds ratio = 0.061, p < 0.001). CONCLUSION: Hydration with BRS could prevent CDDP-induced AKI in patients with esophageal cancer.

Cleavage of Hsp70.1 causes lysosomal cell death under stress conditions.

Autophagy mediates the degradation of intracellular macromolecules and organelles within lysosomes. There are three types of autophagy: macroautophagy, microautophagy, and chaperone-mediated autophagy. Heat shock protein 70.1 (Hsp70.1) exhibits dual functions as a chaperone protein and a lysosomal membrane stabilizer. Since chaperone-mediated autophagy participates in the recycling of ∼30% cytosolic proteins, its disorder causes cell susceptibility to stress conditions. Cargo proteins destined for degradation such as amyloid precursor protein and tau protein are trafficked by Hsp70.1 from the cytosol into lysosomes. Hsp70.1 is composed of an N-terminal nucleotide-binding domain (NBD) and a C-terminal domain that binds to cargo proteins, termed the substrate-binding domain (SBD). The NBD and SBD are connected by the interdomain linker LL1, which modulates the allosteric structure of Hsp70.1 in response to ADP/ATP binding. After the passage of the Hsp70.1-cargo complex through the lysosomal limiting membrane, high-affinity binding of the positive-charged SBD with negative-charged bis(monoacylglycero)phosphate (BMP) at the internal vesicular membranes activates acid sphingomyelinase to generate ceramide for stabilizing lysosomal membranes. As the integrity of the lysosomal limiting membrane is critical to ensure cargo protein degradation within the acidic lumen, the disintegration of the lysosomal limiting membrane is lethal to cells. After the intake of high-fat diets, however, ß-oxidation of fatty acids in the mitochondria generates reactive oxygen species, which enhance the oxidation of membrane linoleic acids to produce 4-hydroxy-2-nonenal (4-HNE). In addition, 4-HNE is produced during the heating of linoleic acid-rich vegetable oils and incorporated into the body via deep-fried foods. This endogenous and exogenous 4-HNE synergically causes an increase in its serum and organ levels to induce carbonylation of Hsp70.1 at Arg469, which facilitates its conformational change and access of activated µ-calpain to LL1. Therefore, the cleavage of Hsp70.1 occurs prior to its influx into the lysosomal lumen, which leads to lysosomal membrane permeabilization/rupture. The resultant leakage of cathepsins is responsible for lysosomal cell death, which would be one of the causative factors of lifestyle-related diseases.

Comparison of the Effects of OPRM1 A118G Polymorphism Using Different Opioids: A Prospective Study.

CONTEXT: µ-opioid receptor gene (OPRM1) A118G polymorphism (rs1799971) causes loss of N-glycosylation sites at the extracellular domain of µ-opioid receptors. G-allele carriers show a limited response to morphine; however, studies investigating the impact of A118G polymorphism on the efficacy of opioids other than morphine are limited. OBJECTIVE: To compare the impact of A118G polymorphism on the efficacy of various opioids. METHODS: This prospective cohort study enrolled 222 in-patients administered one of the following opioid therapies for cancer pain as part of an opioid introduction or rotation strategy: tapentadol extended-release tablets, methadone tablets, hydromorphone controlled-release tablets, oxycodone controlled-release tablets, or transdermal fentanyl patches. The impact of A118G polymorphism on the difference in the Brief Pain Inventory-Short Form score on days three, seven, and 14 from baseline was compared among the groups. RESULTS: Overall, 81, 74, and 67 patients had the AA, AG, and GG genotypes, respectively, with an OPRM1 A118G G-allele variant frequency of 0.47. The reduction in the Brief Pain Inventory-Short Form score after opioid therapy initiation did not differ significantly among the patients with the three A118G genotypes treated with tapentadol (p = 0.84) or methadone (p = 0.97), whereas it was significantly smaller in G-allele carriers than that in AA homozygous patients treated with hydromorphone (p < 0.001), oxycodone (p = 0.031), or fentanyl (p < 0.001). CONCLUSION: Tapentadol and methadone may be more suitable than hydromorphone, oxycodone, and fentanyl for G-allele carriers due to their dual mechanism of action and low susceptibility to OPRM1 A118G polymorphism.

Identification of Factors Contributing to Methadone-Induced Daytime Sleepiness in Cancer Patients and Proposal of the Conversion Ratio from Other Opioids to Oral Methadone: A Retrospective Cohort Study.

Background: When methadone is used to treat cancer pain, the Japanese health insurance system recommends to determine the starting dose according to the equivalency conversion table based on the morphine-equivalent daily dose (MEDD) of prior opioids proposed by the National Comprehensive Cancer Network. Owing to the wide range in variability of the conversion table, methadone increases the incidence of daytime sleepiness. Objective: To identify the factors associated with daytime sleepiness and propose a conversion ratio from pretreatment MEDD to oral methadone that decreases the risk of daytime sleepiness. Design: Retrospective cohort study. Setting/Subjects: One hundred patients who started oral methadone to relieve cancer pain at Ashiya Municipal Hospital (Hyogo, Japan) from January 1, 2013, to August 31, 2022, were enrolled. Measurements: The primary endpoint, the conversion ratio from pretreatment MEDD to oral methadone without daytime sleepiness, was determined using receiver operator characteristic (ROC) curve analysis. Results: The incidence of daytime sleepiness within seven days of methadone initiation was 40.0%. The factors identified as contributing to daytime sleepiness were pretreatment MEDD (odds ratio [OR]: 0.941, 95% confidence interval [CI]: 0.916-0.966, p <0.001) and methadone dose (OR: 1.395, 95% CI: 1.178-1.652, p <0.001). The conversion ratio from pretreatment MEDD to oral methadone was 0.24, with an area under the ROC curve of 0.909 (p <0.001). Conclusions: Daytime sleepiness developed when methadone dose is high relative to pretreatment MEDD. To the best of our knowledge, this is the first study to suggest the conversion ratio from pretreatment MEDD to oral methadone without causing daytime sleepiness.

Differences in the Analgesic Effect of Opioids on Pain in Cancer Patients With Spinal Metastases.

Background: Spinal metastasis pain includes both inflammatory and neuropathic pain, and opioids, which have only a µ-opioid receptor-stimulating effect, are generally less effective in neuropathic pain. However, no previous study has been conducted for the comparisons of the efficacy of opioids in treating spinal metastasis pain. Objective: To compare the efficacy of tapentadol and methadone with other opioids for back pain caused by a metastatic spinal tumor. Design: Retrospective cohort study. Setting/Subjects: A total of 274 patients were enrolled, who started a tapentadol extended-release tablet, methadone tablet, hydromorphone extended-release tablet, oxycodone extended-release tablet, or transdermal fentanyl patch for cancer pain due to spinal metastasis in Japan from January 1, 2013 to October 31, 2021. Measurements: The primary endpoint, the difference in the numerical rating scale (NRS) scores before and seven days after each opioid administration, was compared among the five groups. Results: In patients with numbness, a decrease of the NRS score on day seven compared with before starting each opioid was significantly higher in the tapentadol group than those in the hydromorphone, oxycodone, and fentanyl groups and comparable to that in the methadone group. In patients without numbness, no significant differences were observed in decreases of the NRS scores on day seven among the five groups. Conclusions: Tapentadol and methadone may be more effective than hydromorphone, oxycodone, and fentanyl for cancer pain due to spinal metastasis with numbness.

Reconstruction of the Native Biosynthetic System of Carotenoids in E. coli─Biosynthesis of a Series of Carotenoids Specific to Paprika Fruit.

Capsanthin, capsorubin, cucurbitaxanthin A, and capsanthin 3,6-epoxide, a series of carotenoids specific to the red fruit of paprika (Capsicum annuum), were produced in pathway-engineered Escherichia coli cells. These cells functionally expressed multiple genes for eight carotenogenic enzymes, two of which, paprika capsanthin/capsorubin synthase (CaCCS) and zeaxanthin epoxidase (CaZEP), were designed to be located adjacently. The biosynthesis of these carotenoids, except for capsanthin, was the first successful attempt in E. coli. In a previous study, the levels of capsanthin synthesized were low despite the high expression of the CaCCS gene, which may have been due to the dual activity of CaCCS as a lycopene ß-cyclase and CCS. An enhanced interaction between CaCCS and CaZEP that supplies antheraxanthin and violaxanthin, substrates for CaCCS, was considered to be crucial for an efficient reaction. To achieve this, we adapted S·tag and S-protein binding. The S·tag Thrombin Purification Kit (Novagen) is merchandized for in vitro affinity purification, and S·tag-fused proteins in the E. coli lysate are specifically trapped by S-proteins fixed on the agarose carrier. Furthermore, S-proteins have been reported to oligomerize via C-terminal swapping. In the present study, CaCCS and CaZEP were individually fused to the S·tag and designed to interact on oligomerized S-protein scaffolds in E. coli, which led to the biosynthesis of not only capsanthin and capsorubin but also cucurbitaxanthin A and capsanthin 3,6-epoxide. The latter reaction by CaCCS was assigned for the first time. This approach reinforces the scaffold's importance for multienzyme pathways when native biosynthetic systems are reconstructed in microorganisms.

Synthetic-biological approach for production of neoxanthin in Escherichia coli.

Carotenoids are isoprenoid pigments produced typically in plants, algae, and part of bacteria and fungi. Violaxanthin, neoxanthin, and lutein are xanthophylls biosynthesized specifically in land plants and part of algae. Nowadays, it is feasible to produce violaxanthin and lutein in Escherichia coli by pathway engineering, whereas there is no report to synthesize neoxanthin in E. coli. So far, several genes have been reported to code for neoxanthin synthases, e.g., NSY (NXS), ABA4 and VDL, which were assigned to catalyze a reaction for forming neoxanthin from violaxanthin. However, neither gene of these was common in plants or algae that biosynthesize neoxanthin, nor was confirmed by the E. coli complementation system. This study showed that the algal VDL gene (PtVDL1) was functional in recombinant E. coli cells accumulating violaxanthin to produce neoxanthin, whereas the E. coli cells failed to generate neoxanthin, when the NSY or ABA4 gene was introduced there instead of VDL. This result notes that VDL is one of veritable neoxanthin synthase genes.

Changes of Crocin and Other Crocetin Glycosides in Saffron Through Cooking Models, and Discovery of Rare Crocetin Glycosides in the Yellow Flowers of Freesia Hybrida.

Crocetin glycosides such as crocin are noted as functional food materials since the preventive effects of crocin have been reported against chronic disease and cancer. However, it is unclear how these apocarotenoids are structurally changed through cooking for our intake. We examined such changes in crocetin glycosides (crocin, tricrocin, and crocin-3) contained in saffron (stigmas of Crocus sativus) through cooking models. These glycosides were almost kept stable in boiling for 20 min (a boiled cooking model), while hydrolysis of the ester linkage between glucose and the crocetin aglycone occurred in a grilled cooking model (180°C, 5 min), along with a 13-cis isomerization reaction in a part of crocetin subsequently generated. We further here revealed that the yellow petals of freesia (Freesia x hybrida) with yellow flowers accumulate two unique crocetin glycosides, which were identified to be crocetin (mono)neapolitanosyl ester and crocetin dineapolitanosyl ester. A similar result as above was obtained on their changes through the cooking models. Utility applications of the freesia flowers as edible flowers are also suggested in this study. Additionally, we evaluated singlet oxygen (1O2)-quenching activities of the crocetin glycosides contained in saffron and freesia, and crocetin and 13-cis crocetin contained in the grilled saffron, indicating that they possessed moderate 1O2-quenching activities (IC50 24-64 µM).

Carotenoids: Carotenoid and apocarotenoid analysis-Use of E. coli to produce carotenoid standards.

Authentic samples of many carotenoids are commercially available, but are often too expensive and of insufficient purity. As an alternative, a wide range of carotenoids can be biosynthesized in recombinant Escherichia coli strains. E. coli cells naturally produce the carotenoid biosynthetic precursors and provide a blank slate for manufacturing different target carotenoids, depending on the introduced genes encoding carotenoid biosynthetic enzymes. This chapter presents a series of plasmids that carry genes encoding carotenoid biosynthetic enzymes and methods to produce in E. coli 21 different carotenoids and two apocarotenoids, which can be used as authentic standards. For the structural confirmation of these carotenoids or apocarotenoids, we show their individual spectral data containing MS/MS and UV-visible, along with their biosynthetic routes in the E. coli transformants.

Concomitant palonosetron ameliorates cisplatin-induced nephrotoxicity, nausea, and vomiting: a retrospective cohort study and pharmacovigilance analysis.

BACKGROUND: Cisplatin (CDDP)-induced nephrotoxicity is the most important complication of CDDP treatment. 5-Hydroxytryptamine type 3 receptor antagonists (5-HT3RAs) are widely used to prevent chemotherapy-induced nausea and vomiting (CINV). However, in patients with the triple antiemetic (neurokinin-1 receptor antagonist, 5-HT3RA, and dexamethasone) therapy, the advantage of palonosetron in comparison with other 5-HT3RAs on CDDP-induced nephrotoxicity and CINV remains unclear. In the present study, we investigated the effect of palonosetron on CDDP-induced nephrotoxicity and CINV in patients with the triple antiemetic therapy by a retrospective cohort study and a pharmacovigilance analysis. METHODS: We retrospectively analyzed the effect of 5-HT3RAs on the development of nephrotoxicity and CINV in 110 patients who received CDDP, fluorouracil, and triple antiemetic therapy for the treatment of esophageal cancer. Moreover, the effect of 5-HT3RAs on CDDP-induced nephrotoxicity was validated in patients with the triple antiemetic therapy using the Japanese Adverse Drug Event Report (JADER) database. RESULTS: In a retrospective study, the incidence of nephrotoxicity (≥ grade 1) in patients receiving palonosetron (18%) was significantly lower than that in patients receiving ramosetron (another 5-HT3RA) (36%, p = 0.044). Moreover, severe nephrotoxicity ≥ grade 3 was observed in one patient treated with ramosetron, whereas hematological toxicity was comparable between the two groups (p = 0.553). Furthermore, the incidence rate of CINV within 120 h following CDDP administration in patients treated with palonosetron (18%) was significantly lower than that in patients receiving ramosetron (39%, p = 0.026). JADER database analyses revealed that the reporting odds ratio of palonosetron for CDDP-induced acute kidney injury was 0.282 (95% confidence interval: 0.169-0.472). CONCLUSIONS: The findings of the present study suggested a greater potential of palonosetron against CDDP-induced nephrotoxicity and CINV than other 5-HT3RAs in patients with the triple antiemetic therapy.

Naldemedine-laxative combination: retrospective inpatient study.

OBJECTIVES: The initiation of peripherally acting µ-opioid receptor antagonists (PAMORAs) should be considered 2 weeks after conventional laxatives have failed to achieve an adequate response, and affected patients should be evaluated every 2 weeks thereafter. However, this guidance is difficult to implement in acute care hospitals. This study aimed to examine how naldemedine (PAMORA) should be introduced in combination with other laxatives in the acute care setting. METHODS: This retrospective study evaluated 93 inpatients who received at least four doses of naldemedine. We investigated changes in the average daily defecation counts during the first 7 days after compared with before naldemedine administration and the incidence of diarrhoea. RESULTS: Daily defecation counts during the first 7 days after compared with before naldemedine administration were greater in both the naldemedine, magnesium oxide (MgO) and another laxative group, and in the naldemedine and another laxative other than MgO group than in the naldemedine only group. The incidence rates of diarrhoea were significantly higher in the naldemedine, MgO, and another laxative group, and in the naldemedine and another laxative other than MgO group than in the naldemedine only group. CONCLUSIONS: The introduction of naldemedine alone or in combination with MgO should be considered.

Orange protein, phytoene synthase regulator, has protein disulfide reductase activity.

Orange protein (OR) is known to interact with phytoene synthase (PSY) that commits the first step in carotenoid biosynthesis, and functions as a major post-transcriptional regulator on PSY. We here tried to reveal enzymatic characteristics of OR, that is, protein disulfide reductase (PDR) activity of the Arabidopsis thaliana OR protein (AtOR) was analyzed using dieosin glutathione disulfide (Di-E-GSSG) as a substrate. The AtOR part containing only the zinc (Zn)-finger motif was found to show PDR activity, with an apparent Km of 12,632 nM, Kcat of 11.85 min-1, and KcatKm-1 of 15.6 × 103 M-1sec-1. To evaluate the significance of the N-terminal region of AtOR, we examined the kinetic parameters of a fusion protein composed of the N-terminal region and the Zn-finger motif from AtOR. Consequently, the fusion protein had lower values for Km (2,074 nM) and Kcat (3.18 min-1) and higher catalytic efficiency (25.9 × 103 M-1sec-1) than that of only the Zn-finger motif part, suggesting that the N-terminal region of AtOR should be important for substrate affinity and catalytic efficiency of PDR activity. Complementation experiments with E. coli further demonstrated that AtOR containing the N-terminal region and the Zn-finger motif increases phytoene synthase activity of AtPSY especially under reduced circumstances retaining a NADPH- and H+-regeneration system.

Proton Pump Inhibitors Ameliorate Capecitabine-induced Hand-Foot Syndrome in Patients With Breast Cancer: A Retrospective Study.

BACKGROUND/AIM: Hand-foot syndrome (HFS) is the most common adverse event associated with capecitabine, and its pathogenesis is known to be associated with inflammation. Proton pump inhibitors (PPIs) reportedly exert anti-inflammatory effects; however, the impact of PPIs on capecitabine-induced HFS needs to be clarified in the clinical setting. In the present study, we retrospectively investigated the efficacy and safety of PPIs in patients with breast cancer receiving capecitabine. PATIENTS AND METHODS: We analyzed the effects of PPIs on the development of severe HFS (grade ≥2), progression-free survival (PFS), and overall survival (OS) in 195 patients who received capecitabine chemotherapy for breast cancer. RESULTS: In total, 50 patients (26%) were treated with PPIs, while 145 patients (74%) did not receive PPIs. The incidence of severe HFS was significantly lower in patients who received PPIs (18%) than in patients who did not receive PPIs (43%, p=0.001), and the discontinuation rate of capecitabine therapy due to HFS was also lower in patients receiving PPIs than in those who did not receive PPIs (p=0.003). Multivariate analysis revealed that concomitant PPIs use was an independent factor that significantly contributed to the prevention of severe HFS (odds ratio (OR)=0.265, p=0.003). Meanwhile, no significant difference in median PFS and OS values was observed between patients treated with and without PPIs. CONCLUSION: Concomitant use of PPIs could ameliorate capecitabine-induced HFS in patients with breast cancer.

Heterologous production of novel and rare C30-carotenoids using Planococcus carotenoid biosynthesis genes.

BACKGROUND: Members of the genus Planococcus have been revealed to utilize and degrade solvents such as aromatic hydrocarbons and alkanes, and likely to acquire tolerance to solvents. A yellow marine bacterium Planococcus maritimus strain iso-3 was isolated from an intertidal sediment that looked industrially polluted, from the Clyde estuary in the UK. This bacterium was found to produce a yellow acyclic carotenoid with a basic carbon 30 (C30) structure, which was determined to be methyl 5-glucosyl-5,6-dihydro-4,4'-diapolycopenoate. In the present study, we tried to isolate and identify genes involved in carotenoid biosynthesis from this marine bacterium, and to produce novel or rare C30-carotenoids with anti-oxidative activity in Escherichia coli by combinations of the isolated genes. RESULTS: A carotenoid biosynthesis gene cluster was found out through sequence analysis of the P. maritimus genomic DNA. This cluster consisted of seven carotenoid biosynthesis candidate genes (orf1-7). Then, we isolated the individual genes and analyzed the functions of these genes by expressing them in E. coli. The results indicated that orf2 and orf1 encoded 4,4'-diapophytoene synthase (CrtM) and 4,4'-diapophytoene desaturase (CrtNa), respectively. Furthermore, orf4 and orf5 were revealed to code for hydroxydiaponeurosporene desaturase (CrtNb) and glucosyltransferase (GT), respectively. By utilizing these carotenoid biosynthesis genes, we produced five intermediate C30-carotenoids. Their structural determination showed that two of them were novel compounds, 5-hydroxy-5,6-dihydro-4,4'-diaponeurosporene and 5-glucosyl-5,6-dihydro-4,4'-diapolycopene, and that one rare carotenoid 5-hydroxy-5,6-dihydro-4,4'-diapolycopene is included there. Moderate singlet oxygen-quenching activities were observed in the five C30-carotenoids including the two novel and one rare compounds. CONCLUSIONS: The carotenoid biosynthesis genes from P. maritimus strain iso-3, were isolated and functionally identified. Furthermore, we were able to produce two novel and one rare C30-carotenoids in E. coli, followed by positive evaluations of their singlet oxygen-quenching activities.

Pathway engineering for high-yield production of lutein in Escherichia coli.

Lutein is an industrially important carotenoid pigment, which is essential for photoprotection and photosynthesis in plants. Lutein is crucial for maintaining human health due to its protective ability from ocular diseases. However, its pathway engineering research has scarcely been performed for microbial production using heterologous hosts, such as Escherichia coli, since the engineering of multiple genes is required. These genes, which include tricky key carotenoid biosynthesis genes typically derived from plants, encode two sorts of cyclases (lycopene ε- and ß-cyclase) and cytochrome P450 CYP97C. In this study, upstream genes effective for the increase in carotenoid amounts, such as isopentenyl diphosphate isomerase (IDI) gene, were integrated into the E. coli JM101 (DE3) genome. The most efficient set of the key genes (MpLCYe, MpLCYb and MpCYP97C) was selected from among the corresponding genes derived from various plant (or bacterial) species using E. coli that had accumulated carotenoid substrates. Furthermore, to optimize the production of lutein in E. coli, we introduced several sorts of plasmids that contained some of the multiple genes into the genome-inserted strain and compared lutein productivity. Finally, we achieved 11 mg/l as lutein yield using a mini jar. Here, the high-yield production of lutein was successfully performed using E. coli through approaches of pathway engineering. The findings obtained here should be a base reference for substantial lutein production with microorganisms in the future.

Tapentadol in Cancer Patients with Neuropathic Pain: A Comparison of Methadone, Oxycodone, Fentanyl, and Hydromorphone.

Tapentadol has µ-opioid receptor stimulating and noradrenaline reuptake inhibiting properties, and should be effective for neuropathic pain (NP). However, the efficacy of tapentadol for NP in cancer patients is unclear. Ashiya Municipal Hospital (Hyogo, Japan) enrolled five groups of Japanese cancer patients between January 1, 2013, and December 31, 2019. Patients with NP were administered tapentadol (n = 29), methadone (n = 32), oxycodone (n = 20), fentanyl (n = 26), or hydromorphone (n = 20). The primary endpoint was the difference in the verbal rating scale (VRS) scores between days 0 and 7. The secondary endpoint was the tolerability of each opioid. Before administering opioids among the five groups, there was no significant difference in the VRS score (p = 0.99). The mean reduction in the VRS score on day 7 was significantly greater in the tapentadol group than in the oxycodone group (p = 0.0024) and was larger than that of the methadone, fentanyl, and hydromorphone groups. Regarding safety, the discontinuation rate in the tapentadol group was the lowest of all groups (tapentadol vs. methadone vs. oxycodone vs. fentanyl vs. hydromorphone, 0.0% vs. 6.3% vs. 5.0% vs. 3.8% vs. 10.0%, respectively). This study suggests that tapentadol could be efficacious for cancer patients with NP, and a preferred option in cases that require immediate dose adjustment or for those at high risk for adverse effects. However, the pain intensity was evaluated without pain assessment scales specific to NP. Thus, we think that it is desirable to validate our findings using assessment scales, such as the painDETECT questionnaire in future.

Violaxanthin: natural function and occurrence, biosynthesis, and heterologous production.

Violaxanthin is biosynthesized from zeaxanthin with zeaxanthin epoxidase (ZEP) by way of antheraxanthin only in photosynthetic eukaryotes including higher plants and involved in the xanthophyll cycle to eliminate excessive light energy. Violaxanthin and antheraxanthin have commercially been unavailable, in contrast to commercial production of other carotenoids contained in higher plants, e.g., lycopene, ß-carotene, lutein, zeaxanthin, ß-cryptoxanthin, and capsanthin. One of the reasons is considered that resource plants or other resource organisms do not exist for enabling efficient supply of the epoxy-carotenoids, which are expected to be produced through (metabolic) pathway engineering with heterologous microbial hosts such as Escherichia coli and Saccharomyces cerevisiae. In this Mini-Review, we show heterologous production of violaxanthin with the two microorganisms that have exhibited significant advances these days. We further describe natural function and occurrence, and biosynthesis involving violaxanthin, antheraxanthin, and their derivatives that include auroxanthin and mutatoxanthin. KEY POINTS: • A comprehensive review on epoxy-carotenoids violaxanthin and antheraxanthin. • Pathway engineering for the epoxy-carotenoids in heterologous microbes. • Our new findings on violaxanthin production with the budding yeast.

Capsanthin Production in Escherichia coli by Overexpression of Capsanthin/Capsorubin Synthase from Capsicum annuum.

Capsanthin, a characteristic red carotenoid found in the fruits of red pepper (Capsicum annuum), is widely consumed as a food and a functional coloring additive. An enzyme catalyzing capsanthin synthesis was identified as capsanthin/capsorubin synthase (CCS) in the 1990s, but no microbial production of capsanthin has been reported. We report here the first successful attempt to biosynthesize capsanthin in Escherichia coli by carotenoid-pathway engineering. Our initial attempt to coexpress eight enzyme genes required for capsanthin biosynthesis did not detect the desired product. The dual activity of CCS as a lycopene ß-cyclase as well as a capsanthin/capsorubin synthase likely complicated the task. We demonstrated that a particularly high expression level of the CCS gene and the minimization of byproducts by regulating the seven upstream carotenogenic genes were crucial for capsanthin formation in E. coli. Our results provide a platform for further study of CCS activity and capsanthin production in microorganisms.

Carotenoid Biosynthesis in Liverworts.

In higher plants, there are many studies on carotenoid biosynthetic pathways and their relevant genes. On the other hand, few researches exist on carotenoid biosynthesis in early-land plants containing liverworts, mosses, and ferns. Thus, the evolutionary history of carotenoid biosynthesis genes in land plants has remained unclear. A liverwort Marchantia polymorpha is thought to be one of the first land plants, since this plant remains a primitive figure. Moreover, this liverwort is regarded as the model plant of bryophytes due to several reasons. In this chapter, we review carotenoid biosynthesis in liverworts and discuss the functional evolution and evolutionary history of carotenogenic genes in land plants.

Carotenoid Biosynthesis in Animals: Case of Arthropods.

All the organisms that belong to the animal kingdom had been believed not to synthesize carotenoids de novo. However, several groups of arthropods, which contain aphids, spider mites, and flies belonging to the family Cecidomyiidae, have been unexpectedly shown to possess carotenoid biosynthesis genes of fungal origin since 2010. On the other hand, few reports have shown direct evidence corroborating the catalytic functions of the enzymes that the carotenogenic genes encode. In the present review, we want to overview the carotenoid biosynthetic pathway of the pea aphid (Acyrthosiphon pisum), which was elucidated through functional analysis of carotenogenic genes that exist on its genome using Escherichia coli that accumulates carotenoid substrates, in addition to carotenoid biosynthesis in the other carotenogenic arthropods.