BST1 regulates nicotinamide riboside metabolism via its glycohydrolase and base-exchange activities.

Nicotinamide riboside (NR) is one of the orally bioavailable NAD+ precursors and has been demonstrated to exhibit beneficial effects against aging and aging-associated diseases. However, the metabolic pathway of NR in vivo is not yet fully understood. Here, we demonstrate that orally administered NR increases NAD+ level via two different pathways. In the early phase, NR was directly absorbed and contributed to NAD+ generation through the NR salvage pathway, while in the late phase, NR was hydrolyzed to nicotinamide (NAM) by bone marrow stromal cell antigen 1 (BST1), and was further metabolized by the gut microbiota to nicotinic acid, contributing to generate NAD+ through the Preiss-Handler pathway. Furthermore, we report BST1 has a base-exchange activity against both NR and nicotinic acid riboside (NAR) to generate NAR and NR, respectively, connecting amidated and deamidated pathways. Thus, we conclude that BST1 plays a dual role as glycohydrolase and base-exchange enzyme during oral NR supplementation.

Synergistic effect of bodyweight resistance exercise and protein supplementation on skeletal muscle in sarcopenic or dynapenic older adults.

AIM: The objective of this trial was to investigate the synergistic effects of bodyweight resistance exercise and a protein supplement with vitamin D on skeletal muscle in sarcopenic or dynapenic older adults. METHODS: This was a four-arm randomized controlled trial. Sarcopenic or dynapenic older adults were recruited for this trial. After screening, a total of 112 older adults were randomly allocated among four groups; 28 older adults each were enrolled in the combined resistance exercise and nutritional supplementation group, the exercise alone group, the nutritional supplementation alone group, and the control group. Participants in the combined group and exercise alone groups took part in a bodyweight resistance exercise program for 12 weeks. Protein and vitamin D supplements were provided every day for 12 weeks for the participants in the combined group and nutritional supplementation alone groups. We assessed the echo intensity of participants' thigh muscle using ultrasonography, measured their appendicular muscle mass using a bioelectrical impedance data acquisition system, and tested their knee extension strength and physical function. RESULTS: Participants in the combined group had a significantly greater improvement in rectus femoris echo intensity and knee extension torque than those in the other groups (P < 0.05). Furthermore, the combined program increased appendicular muscle mass in sarcopenic older adults (P < 0.05), but not in older adults with low physical function with normal muscle mass. CONCLUSIONS: The present study confirmed the synergistic effect of bodyweight resistance exercise and protein supplement with vitamin D on muscle quality and muscle strength in sarcopenic or dynapenic older adults. Geriatr Gerontol Int 2019; 19: 429-437.

Hyperosmosis and its combination with nutrient-limitation are novel environmental stressors for induction of triacylglycerol accumulation in cells of Chlorella kessleri.

Triacylglycerols of oleaginous algae are promising for production of food oils and biodiesel fuel. Air-drying of cells induces triacylglycerol accumulation in a freshwater green alga, Chlorella kessleri, therefore, it seems that dehydration, i.e., intracellular hyperosmosis, and/or nutrient-limitation are key stressors. We explored this possibility in liquid-culturing C. kessleri cells. Strong hyperosmosis with 0.9 M sorbitol or 0.45 M NaCl for two days caused cells to increase the triacylglycerol content in total lipids from 1.5 to 48.5 and 75.3 mol%, respectively, on a fatty acid basis, whereas nutrient-limitation caused its accumulation to 41.4 mol%. Even weak hyperosmosis with 0.3 M sorbitol or 0.15 M NaCl, when nutrient-limitation was simultaneously imposed, induced triacylglycerol accumulation to 61.9 and 65.7 mol%, respectively. Furthermore, culturing in three-fold diluted seawater, the chemical composition of which resembled that of the medium for the combinatory stress, enabled the cells to accumulate triacylglycerol up to 24.7 weight% of dry cells in only three days. Consequently, it was found that hyperosmosis is a novel stressor for triacylglycerol accumulation, and that weak hyperosmosis, together with nutrient-limitation, exerts a strong stimulating effect on triacylglycerol accumulation. A similar combinatory stress would contribute to the triacylglycerol accumulation in air-dried C. kessleri cells.

[Dispositional mindfulness modulates automatic transference of disgust into moral judgment].

Previous studies showed that incidental feelings of disgust could make moral judgments more severe. In the present study, we investigated whether individual differences in mindfulness modulated automatic transference of disgust into moral judgment. Undergraduates were divided into high- and low-mindfulness groups based on the mean score on each subscale of the Five Facet Mindfulness Questionnaire (FFMQ). Participants were asked to write about a disgusting experience or an emotionally neutral experience, and then to evaluate moral (impersonal vs. high-conflict personal) and non-moral scenarios. The results showed that the disgust induction made moral judgments more severe for the low "acting with awareness" participants, whereas it did not influence the moral judgments of the high "acting with awareness" participants irrespective of type of moral dilemma. The other facets of the FFMQ did not modulate the effect of disgust on moral judgment. These findings suggest that being present prevents automatic transference of disgust into moral judgment even when prepotent emotions elicited by the thought of killing one person to save several others and utilitarian reasoning conflict.

Randomized phase III study of gemcitabine plus S-1, S-1 alone, or gemcitabine alone in patients with locally advanced and metastatic pancreatic cancer in Japan and Taiwan: GEST study.

PURPOSE: The present phase III study was designed to investigate the noninferiority of S-1 alone and superiority of gemcitabine plus S-1 compared with gemcitabine alone with respect to overall survival. PATIENTS AND METHODS: The participants were chemotherapy-naive patients with locally advanced or metastatic pancreatic cancer. Patients were randomly assigned to receive only gemcitabine (1,000 mg/m(2) on days 1, 8, and 15 of a 28-day cycle), only S-1 (80, 100, or 120 mg/d according to body-surface area on days 1 through 28 of a 42-day cycle), or gemcitabine plus S-1 (gemcitabine 1,000 mg/m(2) on days 1 and 8 plus S-1 60, 80, or 100 mg/d according to body-surface area on days 1 through 14 of a 21-day cycle). RESULTS: In the total of 834 enrolled patients, median overall survival was 8.8 months in the gemcitabine group, 9.7 months in the S-1 group, and 10.1 months in the gemcitabine plus S-1 group. The noninferiority of S-1 to gemcitabine was demonstrated (hazard ratio, 0.96; 97.5% CI, 0.78 to 1.18; P < .001 for noninferiority), whereas the superiority of gemcitabine plus S-1 was not (hazard ratio, 0.88; 97.5% CI, 0.71 to 1.08; P = .15). All treatments were generally well tolerated, although hematologic and GI toxicities were more severe in the gemcitabine plus S-1 group than in the gemcitabine group. CONCLUSION: Monotherapy with S-1 demonstrated noninferiority to gemcitabine in overall survival with good tolerability and presents a convenient oral alternative for locally advanced and metastatic pancreatic cancer.

p-Hydroxyamphetamine causes prepulse inhibition disruption in mice: contribution of serotonin neurotransmission.

p-Hydroxyamphetamine (p-OHA) has been shown to have a number of pharmacological actions, including causing abnormal behaviors such as increased locomotor activity and head-twitch response in rodents. We have recently reported that intracerebroventricular (i.c.v.) administration of p-OHA dose-dependently induces prepulse inhibition (PPI) disruption in mice, which is attenuated by pretreatment with haloperidol, clozapine or several dopaminergic agents. Haloperidol and clozapine have affinities for serotonergic (especially 5-HT(2A)) receptors. To investigate the involvement of the central serotonergic systems in p-OHA-induced PPI disruption, herein we tested several serotonergic agents to determine their effects on p-OHA-induced PPI disruption. p-OHA-induced PPI disruption was attenuated by pretreatment with 5,7-dihydroxytryptamine (5,7-DHT, a neurotoxin which targets serotonin-containing neurons) and p-chlorophenylalanine (PCPA, a serotonin synthesis inhibitor). p-OHA-induced PPI disruption was also attenuated by pretreatment with ketanserin (a 5-HT(2A/2C) receptor antagonist) and MDL100,907 (a selective 5-HT(2A) receptor antagonist). These data suggest that p-OHA-induced PPI disruption may involve increased serotonin release into the synaptic cleft, which then interacts with the post-synaptic 5-HT(2A) receptor.

Pharmacological characterizations of memantine-induced disruption of prepulse inhibition of the acoustic startle response in mice: involvement of dopamine D2 and 5-HT2A receptors.

It has recently been reported that psychotic symptoms in patients such as those with Parkinson's disease dementia (PDD) and Lewy body dementia (LBD) may worsen following treatment with memantine, a non-competitive NMDA receptor antagonist. Prepulse inhibition (PPI) of the acoustic startle response (ASR) is used as a measure for sensorimotor gating and it has been reported that PPI is disrupted by memantine. However, the mechanism of memantine-induced PPI disruption remains unclear. In the present study, we investigated the effects of memantine on PPI of the ASR in mice. Memantine (1.25-20mg/kg, intraperitoneally) increased the ASR and dose-dependently decreased PPI for all prepulse intensities tested. This effect of memantine on PPI was attenuated by pretreatment with the antipsychotics clozapine (3 and 6 mg/kg), risperidone (0.3mg/kg) and haloperidol (0.5mg/kg), the selective D(2) antagonist sulpiride (40 mg/kg) and 5-HT(2A/2C) antagonist ketanserin (2 and 4 mg/kg) but not with the selective D(1) antagonist SCH23390 (0.05 and 0.1mg/kg). Clozapine (6 mg/kg) and risperidone (0.3 mg/kg) significantly attenuated the increased startle amplitude in the memantine-treated groups. These results suggest that involvement of dopaminergic and/or serotonergic neurotransmission may play a crucial role in memantine-induced PPI disruption, and additionally, indicate that blockade of either the D(2) or 5-HT(2A) receptor may prevent disruption of PPI induced by memantine in mice. Conceivably, memantine may exacerbate psychotic symptoms in patients with PDD and LBD.

Behavioral and neurochemical characterization of mice deficient in the N-type Ca2+ channel alpha1B subunit.

N-type voltage-dependent calcium channels (VDCCs) play an important role in neurotransmission, synaptic plasticity, and brain development. They are composed of several subunits named alpha(1), alpha(2), delta, beta and gamma. The alpha(1) subunit is essential for channel functions and determines fundamental channel properties. Since N-type VDCC are critically involved in the release of neurotransmitters and clinical relevance, we predicted that alpha(1) subunit KO mice would show several alterations in behavior. In the present study, we investigated neuronal functions in mice lacking the alpha(1B) (Ca(V)2.2) subunit of the N-type calcium channels. Ca(V)2.2(-/-) mice exhibited a significant increase in locomotion on an activity wheel during the dark phase. Furthermore, when challenged with apomorphine, mutant mice showed enhanced locomotor activity. Cognitive functions were examined using a Y-maze task for short-term memory and a passive avoidance task for long-term memory. The Y-maze revealed no differences in spontaneous alternation behavior between mutant and wild-type mice. The passive avoidance test revealed that the latency time in mutant mice was significantly decreased. The mutant mice showed prepulse inhibition deficits reminiscent of the sensorimotor gating deficits observed in a large majority of schizophrenic patients. Decreases in baseline levels of dopamine and serotonin within the striata and frontal cortices of mutant mice were also observed. These results suggest that Ca(2+) in the central nervous system modulates various neurophysiological functions, such as locomotor activity, long-term memory, and sensorimotor gating through the alpha(1B) subunit of the N-type calcium channels.

PEGylated lactoferrin enhanced its hepatoprotective effects on acute liver injury induced by carbon tetrachloride in rats.

Polyethylene glycol (PEG) is attached to proteins in order to increase their half-life in circulation and reduce their immunogenicity in vivo. The present study was conducted to examine whether two different sizes of PEGylated bovine lactoferrin (40k-PEG-bLf and 20k-PEG-bLf) would enhance the protective effect of native bLf on liver injury induced by carbon tetrachloride (CCl(4)) in rats. Silymarin, a known hepatoprotective drug was used as a positive control. Compared to native bLf, the treatment of PEGylated bLf more markedly prevented the elevation of serum levels of hepatic enzyme markers and inhibited fatty degeneration and the hepatic necrosis induced by CCl(4). 40k-PEG-bLf showed a more significant suppressive effect on CCl(4)-induced hepatic injury than 20k-PEG-bLf. The treatment with PEGylated bLf elevated serum SOD activity reduced by CCl(4) more significantly than native bLf. 40k-PEG-bLf enhanced serum SOD activity more significantly than 20k-PEG-bLf. Immunohistochemical study showed that the PEGylation of bLf enhanced its intracellular transportation to hepatocytes. The increases in intracellular transportation of the PEGylated bLf in order were: 40k-PEG-bLf>20k-PEG-bLf>native bLf. These findings suggested that the mechanism of the enhancement of hepatoprotective effect by PEGylated bLf was associated with an increase in the intracellular transportation of PEGylated bLf in hepatocytes.

Dietary histidine ameliorates murine colitis by inhibition of proinflammatory cytokine production from macrophages.

BACKGROUND & AIMS: Elemental diet (ED) is effective for human Crohn's disease (CD). Although some of this effectiveness may be due to its low antigenic load and low fat content, the mechanisms remain unclear. We sought to assess the role of histidine, one of the constituent amino acids of ED, in controlling colitis. METHODS: The interleukin (IL)-10-deficient (IL-10(-/-)) cell transfer model of colitis was used. SCID mice with colitis induced by transfer of IL-10(-/-) cells were maintained on experimented diets containing either single amino acids or a mixture. The severity of colitis was assessed by wet colon weight. Colonic tumor necrosis factor (TNF)-alpha messenger RNA (mRNA) expression was detected by quantitative reverse-transcription polymerase chain reaction. Mouse peritoneal macrophages were stimulated by lipopolysaccharides (LPS), with or without amino acids. The concentration of cytokines in the supernatant was determined by enzyme-linked immunosorbent assay. Inhibitor of nuclear factor (NF)-kappaB-alpha and nuclear p65 were confirmed by immunoblotting. RESULTS: In the IL-10(-/-) transfer model, dietary histidine, but not alanine, reduced histologic damage and colon weight and TNF-alpha mRNA expression. Histidine inhibited LPS-induced TNF-alpha and IL-6 production by mouse macrophages in a concentration-dependent manner, whereas alanine or histidine-related metabolites had no such effect. Histidine inhibited LPS-induced NF-kappaB in macrophages. CONCLUSIONS: These results showed that histidine could be a novel therapeutic agent for CD by inhibition of NF-kappaB activation, following down-regulation of proinflammatory cytokine production by macrophages. Thus, our studies provided new insights into the roles of amino acid metabolism in the pathophysiology of CD and for therapeutic strategies.

DNA sequence selective adenine alkylation, mechanism of adduct repair, and in vivo antitumor activity of the novel achiral seco-amino-cyclopropylbenz[e]indolone analogue of duocarmycin AS-I-145.

AS-I-145 is a novel achiral seco-amino-cyclopropylbenz[e]indolone (seco-amino-CBI) analogue of duocarmycin that has evolved from an alternative strategy of designing CC-1065/duocarmycin agents lacking the characteristic chiral center of the natural agents. The sequence specificity of this compound was assessed by a Taq polymerase stop assay, identifying the sites of covalent modification on plasmid DNA. The adenine-N3 adducts were confirmed at AT-rich sequences using a thermally induced strand cleavage assay. These studies reveal that this compound retains the inherent sequence selectivity of the related natural compounds. The AS-I-145 sensitivity of yeast mutants deficient in excision and post-replication repair (PRR) pathways was assessed. The sensitivity profile suggests that the sequence-specific adenine-N3 adducts are substrates for nucleotide excision repair (NER) but not base excision repair (BER). Single-strand ligation PCR was employed to follow the induction and repair of the lesions at nucleotide resolution in yeast cells. Sequence specificity was preserved in intact cells, and adduct elimination occurred in a transcription-coupled manner and was dependent on a functional NER pathway and Rad18. The involvement of NER as the predominant excision pathway was confirmed in mammalian DNA repair mutant cells. AS-I-145 showed good in vivo antitumor activity in the National Cancer Institute standard hollow fiber assay and was active against the human breast MDA-MD-435 xenograft when administered i.v. or p.o. Its novel structure and in vivo activity renders AS-I-145 a new paradigm in the design of novel achiral analogues of CC-1065 and the duocarmycins.