Systemic immune responses do not affect significant immune responses in the skin.

Fish skin plays an important role in defending against pathogens in water, primarily through the secretion of skin mucus containing various immune-related factors. Local immune responses in the skin activate systemic immune responses by inflammatory cytokines. However, it remains unclear whether immune responses in the skin occur after systemic immune responses caused by pathogen invasion into the fish body. This study aimed to clarify the relationship between systemic immune responses and skin responses after intraperitoneal injection of formalin-killed cells (FKC) of Vibrio anguillarum. Although systemic inflammatory responses were observed in the spleen after injection, expression changes in the skin did not show significant differences. In contrast, expression of hemoglobin subunit genes significantly increased in the skin after FKC injection, suggesting that erythrocytes infiltrate extravascularly.

Euphausia pacifica emulsified oil powder improves sleep quality in partially sleep-restricted healthy volunteers.

Although it is known that adequate sleep is crucial for maintaining a healthy lifestyle, approximately 30% of the general population has experienced insomnia. Thus, a better understanding of the relationship between food components and sleep quality is needed. North Pacific krill, Euphausia pacifica, is rich in marine n-3 polyunsaturated fatty acids in phospholipid form as well as 8R-hydroxy-eicosapentanoic acid. Here, emulsified oil powder derived from this krill was used in a trial involving 64 participants to assess its potential to enhance sleep quality. Consumption of the powdered emulsified oil was found to reduce drowsiness upon waking and enhance fatigue recovery, and for participants aged 40 and above, an improvement in sleep cycle was observed. In conclusion, consumption of krill emulsified oil powder was effective in enhancing sleep quality for individuals with partial sleep restrictions.

Impact of antimicrobial stewardship implementation on the antibiotic use and susceptibility in a Japanese long-term care hospital.

BACKGROUND: Antimicrobial use (AMU) is closely related to the emergence of antimicrobial-resistant (AMR) bacteria. Meanwhile, long-term care hospitals (LTCHs) have been pointed out to be important reservoirs for AMR. However, evidence illustrating the association between AMU and AMR in LTCHs is lacking compared to that of acute care hospitals. METHODS: We evaluated the impact of an antimicrobial stewardship (AS) program implementation, in a LTCH on AMU and antibiotic susceptibility between three periods: the pre-AS-period (pre-AS); the first period after AS implementation (post-AS 1), in which initiated recommendation the blood culture collection and definitive therapy by AS team; and the second period (post-AS 2), implementation of a balanced use of antibiotics was added. RESULTS: After the AS implementation, a significant increase in the number of blood cultures collected was observed. Conversely, the AMU of piperacillin-tazobactam (PIPC/TAZ), which has activity against Pseudomonas aeruginosa, was increased and occupied 43.0% of all injectable AMU in post-AS 1 compared with that in pre-AS (35.5%). In the post-AS 2 period, we analyzed the %AUD and recommended hospital-wide PIPC/TAZ sparing; this resulted in the significant reduction in %AUD of PIPC/TAZ, which was associated with improved susceptibility of P. aeruginosa to PIPC/TAZ. CONCLUSIONS: These results suggest that AS programs aimed at implementing antibiotic sparing may lead to improve AMR, highlighting the necessity of correcting overuse of a single class of antibiotics and usefulness of AMU monitoring in the LTCH setting.

8(R)-Hydroxyeicosapentaenoic acid (8R-HEPE) induces transcription of cholesterol efflux receptors via activation of liver X receptor in macrophages.

Dyslipidemia is a risk factor for the development of atherosclerotic cardiovascular disease. 8-Hydroxyeicosapentaenoic acid (8-HEPE) from North Pacific krill (Euphausia pacifica) is known to reduce plasma low-density lipoprotein (LDL) cholesterol levels and increase plasma high-density lipoprotein cholesterol levels in LDL receptor knock-out mice fed a western diet. Moreover, 8-HEPE also reduces the area of aortic atherosclerosis in apoE knock-out mice fed the same diet. In this study, we examined the stereochemical-specific activity of 8-HEPE for inducing expression of cholesterol efflux receptors (Abca1 and Abcg1) in J774.1 cells. Our findings show 8R-HEPE induces the expression of Abca1 and Abcg1 via activation of liver X receptor, whereas 8S-HEPE elicits no such activity. These results suggest that 8R-HEPE derived from North Pacific krill may have beneficial effects against dyslipidemia.

Type I interferon induced by polyinosinic-polycytidylic acid does not contribute to the efficacy of a formalin-killed cell vaccine against Edwardsiella piscicida in the Japanese flounder (Paralichthys olivaceus).

Polyinosinic-polycytidylic acid (poly I:C) is a type of pathogen-associated molecular pattern that can strongly induce the expression of type I interferon (I-IFN). Our previous study has demonstrated that the combination of poly I:C with a recombinant protein antigen not only stimulated the expression of I-IFN but also conferred protection against Edwardsiella piscicida in the Japanese flounder (Paralichthys olivaceus). In this study, our aim was to develop a better immunogenic and protective fish vaccine, for which we intraperitoneally coinjected P. olivaceus with poly I:C and formalin-killed cells (FKCs) of E. piscicida and compared the efficiency of protection against E. piscicida infection with that of FKC vaccine alone. Results showed that the expression levels of I-IFN, IFN-γ, interleukin (IL)-1ß, tumor necrosis factor (TNF)-α, and the interferon-stimulated genes (ISGs) ISG15 and Mx were significantly increased in the spleen of fish inoculated with poly I:C + FKC. The results of ELISA showed that the levels of specific serum antibodies in the FKC and FKC + poly I:C groups were gradually increased until 28 days postvaccination and were significantly higher than those in the PBS and poly I:C groups. At 3 weeks after vaccination in the challenge test, the respective cumulative mortality rates of fish in the PBS, FKC, poly I:C, and poly I:C + FKC groups were 46.7%, 20.0%, 33.3%, and 13.3% under low-concentration challenge and 93.3%, 46.7%, 78.6%, and 53.3% under high-concentration challenge. This study showed that poly I:C may not provide an effective adjuvant effect with FKC vaccine for intracellular bacterial infections.

Total Synthesis of (+)-Coriamyrtin via a Desymmetrizing Strategy Involving a 1,3-Cyclopentanedione Moiety.

We describe the total synthesis of (+)-coriamyrtin, which bears a highly functionalized cis-hydrindane skeleton and is a widely known neurotoxin of the Coriariaceae family. Our synthetic strategy involves the highly stereoselective construction of the cis-hydrindane skeleton via a desymmetrizing strategy involving a 1,3-cyclopentanedione moiety using an intramolecular aldol reaction and the formation of the 1,3-diepoxide moiety of coriamyrtin through the elaborate functionalization of the cyclopentane ring in the bicyclic structure.

Whole-genome analysis of red sea bream iridovirus spread in 2021 in Japan provided epidemiological and viral traits insight.

Red sea bream iridovirus (RSIV) is the pathogen that causes red sea bream iridoviral disease. It causes a huge loss to the Japanese aquaculture industry. In 2021, outbreaks of red sea bream iridovirus occurred in South Japan. This study analysed nine whole-genome sequences of RSIV isolated in Oita and Ehime Prefectures in 2021 using a short-read next-generation sequencer. Nine isolates had highly uniform sequences, and there was no variant depending on locations or host species. Phylogenetic analyses with other reported megalocytivirus isolates showed that RSIV isolated in 2021 was genetically different from RSIV previously isolated in Oita and Ehime Prefectures in 2017-2019. These results suggest that RSIV isolated in Oita and Ehime Prefectures in 2021 might spread from a common ancestor different from the recent one. Additionally, it was found that RSIV isolated in 2021 had sequence mutations on protein-coding sequences that may be involved in viral pathogenicity and infectivity.

Model Synthetic Study of Tutin, a Picrotoxane-Type Sesquiterpene: Stereoselective Construction of a cis-Fused 5,6-Ring Skeleton.

Picrotoxinin, coriamyrtin, and tutin are representative natural products classified as picrotoxane-type sesquiterpenes and they function as strong neurotoxins. Because they possess a cis-fused 5,6-ring skeleton with a highly congested functionalization, organic chemistry researchers have pursued the development of a stereoselective synthesis method for such skeleton. This study aims to stereoselectively synthesize the cis-fused 5,6-ring skeleton with two tetrasubstituted carbons at both angular positions using a model compound. The results revealed that the desymmetrization of the 2-methyl-1,3-cyclopentanedione moiety via the DL-proline-mediated intramolecular aldol reaction of a pentanal derivative bearing an isopropenyl group and the five-membered ring at the 3- and 5-position, respectively, provided the desired cis-fused skeleton. This reaction can construct four contiguous stereogenic centers of the bicyclic skeleton with the two angular positions in good yield with high stereoselectivity. Further, this reaction was applied to the kinetic resolution of the racemate using L-proline, providing the enantiomeric pure aldol product with the desired skeleton. This method can be utilized for total synthesis of picrotoxane-type sesquiterpenes.

Indium(III) bromide-mediated ß-selective thioglycosylation of 1,2,4-O-orthoacetylglucose derivatives.

1,2,4-O-Orthoacetyl-α-d-glucose possesses a skew-boat glucopyranose ring whose steric strain is expected to show high reactivity. This study describes the ß-selective thioglycosylation of 1,2,4-O-orthoacetyl-α-d-glucose. Indium(III) bromide catalyzes the reaction in trifluoromethylbenzene at ambient temperature in the presence of molecular sieves 4A, resulting in the corresponding thioglycoside product with perfect ß-selectivity and high yields. The presented glycosylation might be useful for the synthesis of functional molecules and natural products possessing sugar moieties.

Euphausia pacifica (North Pacific Krill): Review of Chemical Features and Potential Benefits of 8-HEPE against Metabolic Syndrome, Dyslipidemia, NAFLD, and Atherosclerosis.

Marine n-3 fatty acids are well known to have health benefits. Recently, krill oil, which contains phospholipids, has been in the spotlight as an n-3 PUFA-containing oil. Euphausia pacifica (E. pacifica), also called North Pacific krill, is a small, red crustacean similar to shrimp that flourishes in the North Pacific Ocean. E. pacifica oil contains 8-hydroxyeicosapentaenoic acid (8-HEPE) at a level more than 10 times higher than Euphausia superba oil. 8-HEPE can activate the transcription of peroxisome proliferator-activated receptor alpha (PPARα), PPARγ, and PPARδ to levels 10, 5, and 3 times greater than eicosapentaenoic acid, respectively. 8-HEPE has beneficial effects against metabolic syndrome (reduction in body weight gain, visceral fat area, amount of gonadal white adipose tissue, and gonadal adipocyte cell size), dyslipidemia (reduction in serum triacylglycerol and low-density lipoprotein cholesterol and induction of serum high-density lipoprotein cholesterol), atherosclerosis, and nonalcoholic fatty liver disease (reduction in triglyceride accumulation and hepatic steatosis in the liver) in mice. Further studies should focus on the beneficial effects of North Pacific krill oil products and 8-HEPE on human health.

Total Synthesis of Macaranin B.

This study describes the total synthesis of macaranin B, a naturally occurring ellagitannin containing 1-O-galloyl and 3,6-O-macaranoyl groups in an axial-rich d-glucose. The key steps of the synthesis include an oxidative coupling reaction of galloyl groups with 1,2,4-orthoacetylglucose moiety and oxa-Michael addition/elimination using an orthoquinone monoketal. This facilitates the construction of the macaranoyl group and the first total synthesis of macaranin B.

A yeast-based screening system identified bakkenolide B contained in Petasites japonicus as an inhibitor of interleukin-2 production in a human T cell line.

Ca2+ signaling is related to various diseases such as allergies, diabetes, and cancer. We explored Ca2+ signaling inhibitors in natural resources using a yeast-based screening method and found bakkenolide B from the flower buds of edible wild plant, Petasites japonicus, using the YNS17 strain (zds1Δ erg3Δ pdr1/3Δ). Bakkenolide B exhibited growth-restoring activity against the YNS17 strain and induced Li+ sensitivity of wild-type yeast cells, suggesting that it inhibits the calcineurin pathway. Additionally, bakkenolide B inhibited interleukin-2 production at gene and protein levels in Jurkat cells, a human T cell line, but not the in vitro phosphatase activity of human recombinant calcineurin, an upstream regulator of interleukin-2 production. Furthermore, bakkenolide A showed weak activity in YNS17 and Jurkat cells compared with bakkenolide B. These findings revealed new biological effects and the structure-activity relationships of bakkenolides contained in P. japonicus as inhibitors of interleukin-2 production in human T cells.

ß-Selective Glycosylation Using Axial-Rich and 2-O-Rhamnosylated Glucosyl Donors Controlled by the Protecting Pattern of the Second Sugar.

Herein, we describe two counterexamples of the previously reported ß/α-selectivity of 96/4 for glycosylation using ethyl 2-O-[2,3,4-tris-O-tert-butyldimethylsilyl (TBS)-α-L-rhamnopyranosyl]-3,4,6-tris-O-TBS-thio-ß-D-glucopyranoside as the glycosyl donor. Furthermore, we investigated the effects of protecting group on the rhamnose moieties in the glycosylation with cholestanol and revealed that ß-selectivity originated from the two TBS groups at the 3-O and 4-O positions of rhamnose. In contrast, the TBS group at the 2-O position of rhamnose hampered the ß-selectivity. Finally, the ß/α-selectivity during the glycosylation was enhanced to ≥99/1. The results obtained herein suggest that the protecting groups on the sugar connected to the 2-O of a glycosyl donor with axial-rich conformation can control the stereoselectivity of glycosylation.

Identification of a novel enzyme from E. pacifica that acts as an eicosapentaenoic 8R-LOX and docosahexaenoic 10R-LOX.

North Pacific krill (Euphausia pacifica) contain 8R-hydroxy-eicosapentaenoic acid (8R-HEPE), 8R-hydroxy-eicosatetraenoic acid (8R-HETE) and 10R-hydroxy-docosahexaenoic acid (10R-HDHA). These findings indicate that E. pacifica must possess an R type lipoxygenase, although no such enzyme has been identified in krill. We analyzed E. pacifica cDNA sequence using next generation sequencing and identified two lipoxygenase genes (PK-LOX1 and 2). PK-LOX1 and PK-LOX2 encode proteins of 691 and 686 amino acids, respectively. Recombinant PK-LOX1 was generated in Sf9 cells using a baculovirus expression system. PK-LOX1 metabolizes eicosapentaenoic acid (EPA) to 8R-HEPE, arachidonic acid (ARA) to 8R-HETE and docosahexaenoic acid (DHA) to 10R-HDHA. Moreover, PK-LOX1 had higher activity for EPA than ARA and DHA. In addition, PK-LOX1 also metabolizes 17S-HDHA to 10R,17S-dihydroxy-docosahexaenoic acid (10R,17S-DiHDHA). PK-LOX1 is a novel lipoxygenase that acts as an 8R-lipoxygenase for EPA and 10R-lipoxygenase for DHA and 17S-HDHA. Our findings show PK-LOX1 facilitates the enzymatic production of hydroxy fatty acids, which are of value to the healthcare sector.

Synthesis of an Ellagitannin Component, the Macaranoyl Group with a Tetra-ortho-Substituted Diaryl Ether Structure.

Herein, a practical synthesis of the macaranoyl group contained in ellagitannins, i.e., a C-O digallate structure with a tetra-ortho-substituted diaryl ether bond, is described. The methodology involved an oxa-Michael addition/elimination reaction between a brominated ortho-quinone monoketal and a phenol with a hexahydroxydiphenoyl moiety in the presence of 18-crown-6 under dark conditions, followed by reductive aromatization. The existence of rotamers originating from the constructed ether moiety is discussed as well.

Total Synthesis of Mallotusinin.

The total synthesis of mallotusinin, which bears a tetrahydroxydibenzofuranoyl (THDBF) bridge between the 2-oxygen and 4-oxygen of glucose on corilagin with a 3,6-O-(R)-hexahydroxydiphenoyl (HHDP) bridge, is described. The key features of the total synthesis are: 1) improvements of our previously reported method to synthesize corilagin; 2) establishment of the THDBF skeleton via an unusual intramolecular SN Ar reaction of an HHDP analogue, and 3) the application of a two-step bislactonization strategy for a HHDP bridge construction into the 2,4-O-THDBF bridge. Oxidative phenol coupling of 1,2,4-orthoacetyl-3,6-di-(4-O-benzylgalloyl)-α-d-glucopyranose and the orthoester cleavage of the coupling product without the pyranose-furanose ring transformation are key reactions for the improved synthesis of corilagin, which enabled the adequate supply of a corilagin precursor that was required to develop the mallotusinin synthesis. These established methods are expected to help develop the synthesis of other ellagitannins with a bridge between the two oxygens of corilagin.

8-HEPE-Concentrated Materials from Pacific Krill Improve Plasma Cholesterol Levels and Hepatic Steatosis in High Cholesterol Diet-Fed Low-Density Lipoprotein (LDL) Receptor-Deficient Mice.

Eicosapentaenoic acid (EPA), one of the N-3 polyunsaturated fatty acids (n-3 PUFAs), is a major active ingredient of fish that contributes to improve dyslipidemia. Recently, we demonstrated that 8-hydroxyeicosapentaenoic acid (8-HEPE) had a more positive effect on metabolic syndrome than EPA, and that 8-HEPE induced peroxisome proliferator-activated receptor (PPAR)α activation in the liver. We investigated the effects of 8-HEPE-concentrated materials from Pacific krill on dyslipidemia and hepatic steatosis in low-density lipoprotein (LDL) receptor-deficient (LDLR-KO) mice. Eight-week-old male LDLR-KO mice were fed a Western diet (0.15% cholesterol, WD), WD supplemented with 8-HEPE-concentrated materials from Pacific krill (8-HEPE included; WD +8-HEPE), or a standard diet (SD) for eighteen weeks, respectively. Murine J774.1 macrophages were incubated in the absence or presence of 8-HEPE (50 µM) or EPA (50 µM). 8-HEPE-concentrated materials significantly increased the plasma high-density lipoprotein (HDL)-cholesterol level, and decreased the plasma LDL-cholesterol and hepatic triglyceride levels in WD-fed LDLR-KO mice. Moreover, the rate of Oil Red O-positive staining was higher in the liver of WD-fed LDLR-KO mice than in that of 8-HEPE + WD-fed LDLR-KO mice. 8-HEPE but not EPA significantly increased gene expression levels of ABCA1, CD36, and interleukin 6 (IL-6) in murine J774.1 macrophages compared with those in the control. These results suggest that 8-HEPE-concentrated materials improve dyslipidemia and hepatic steatosis increasing ABCA1, CD36, and IL-6 gene expressions in macrophages.

Total Synthesis of Casuarinin.

This study involves the total synthesis of casuarinin, a naturally occurring ellagitannin, in which an open-chain glucose is esterified with two (S)-hexahydroxydiphenoyl (HHDP) groups. One HHDP group incorporates a C-glycosidic bond between its benzene ring and the glucose moiety, which was constructed with complete stereoselectivity using a benzyl oxime group that opened the glucopyranose ring and acted as a scaffold for C-glycoside production. This total synthesis enables future structure-activity relationship studies of this compound.

Synthesis of diaryl ether components of ellagitannins using ortho-quinone with consonant mesomeric effects.

Methods for synthesizing C-O digallate structures, the basic unit of diaryl ether components of natural ellagitannins, are described. In the designed building block derived from gallic acid, consonantly overlapped mesomeric effects enhanced its electrophilicity. This building block demonstrated substantial reactivity to improve the synthesis of dehydrodigalloyl, tergalloyl, and valoneoyl groups.

Euphausia pacifica as a source of 8(R)-hydroxy-eicosapentaenoic acid (8R-HEPE), 8(R)-hydroxy-eicosatetraenoic acid (8R-HETE) and 10(R)-hydroxy-docosahexaenoic acid (10R-HDHA).

Although not fully investigated, 8-HEPE, 8-HETE, and 10-HDHA have potentially beneficial effects for human health. Euphausia pacifica (North Pacific krill) is unique in containing several ppm level of 8R-HEPE, and sub-ppm levels of 8R-HETE and 10R-HDHA. Obtaining sufficient quantities of these compounds is a major bottleneck for conducting in vivo experiments to evaluate their biological activities. In this study, we examined an efficient way of obtaining 8R-HEPE, 8R-HETE, and 10R-HDHA by enzymatic production in E. pacifica. We devised a novel method to purify 199.4 mg of 8R-HEPE, 2.1 mg of 8R-HETE and 5.6 mg of 10R-HDHA from 1 kg of E. pacifica. We identified the stereochemistry of the hydroxy group at C-8 of HEPE and HETE and C-10 of HDHA as the R configuration by chiral column chromatography analysis using LC/QTOFMS.Abbreviations: 8-HEPE: 8-hydroxy-eicosapentaenoic acid; 8-HETE: 8-hydroxy-eicosatetraenoic acid; 10-HDHA: 10-hydroxy-docosahexaenoic acid; EPA: eicosapentaenoic acid; TLC-FID, thin layer chromatograph-Flame Ionization Detector; LC/QTOFMS: liquid chromatography/hybrid quadrupole time of flight mass spectrometry.