Improved Refolding of a Human IgG1 Fc (CH2-CH3) Scaffold from Its Inclusion Body in E. coli by Alkaline Solubilization.

Recently, we developed a platform strategy for hinge-deficient human immunoglobulin G1 (IgG1) Fc fusion as a non-immunostimulatory Fc fusion system. As a starting point to establish a promising approach for generating hinge-deficient Fc fusion proteins in Escherichia (E.) coli, we selected a CH2-CH3 scaffold as a model protein for evaluation. Recombinant CH2-CH3, expressed as inclusion bodies, was solubilized with various denaturants (urea, sarkosyl, sodium dodecyl sulfate (SDS), 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS), or Triton X-100) in neutral (phosphate-buffered saline (PBS), pH 8) or alkaline (50 or 500 mM N-cyclohexyl-3-aminopropanesulfonic acid (CAPS), pH 11) buffer at 25 °C. Similar to the authentic CH2-CH3 produced in Chinese hamster ovary (CHO) cells, all denaturants, except urea in CAPS buffer but not in PBS, were found to elicit the dimer formation of solubilized CH2-CH3 on SDS-polyacrylamide gel electrophoresis (PAGE). After dialysis with PBS, sarkosyl-soluble CH2-CH3 inclusion bodies were successfully purified using protein G-Sepharose, indicating their successful refolding. Compared to the purified CH2-CH3 from its sarkosyl-soluble inclusion bodies in neutral buffer, that in 500 mM CAPS alkaline buffer revealed substantial structure-related similarities, such as secondary structures and thermal stabilities, as measured by circular dichroism spectroscopy, to authentic CH2-CH3. Native PAGE analysis also supported the above data. Therefore, solubilization at alkaline pH is an essential factor that promotes the refolding of CH2-CH3. Dimer formation of CH2-CH3 on SDS-PAGE may act as a surrogate marker for its protein refolding status. Our observations may provide important hints toward downstream processing of Fc-fusion production in E. coli.

Selective Visualization of Administrated Arachidonic and Docosahexaenoic Acids in Brain Using Combination of Simple Stable Isotope-Labeling Technique and Imaging Mass Spectrometry.

We developed a new method for monitoring the distribution of administrated fatty acids in the body by combination of a stable isotope-labeling technique and imaging mass spectrometry (IMS). The developed stable isotope-labeling technique is very simple and able to adapt to all the fatty acid species. In this study, we synthesized stable isotope-labeled arachidonic acid (AA) and docosahexaenoic acid (DHA), and they were simultaneously administrated to mice to examine their migrations and distributions in the brain. The administrated AA and DHA have two more molecular weights compared to the originals and apparently were distinguished from the originally accumulated AA and DHA in the brain using IMS. As a result, we reveal that the administered AA and DHA first accumulated in the hippocampus and cerebellar cortex in the brain. This technique does not use radio isotopes and would appear to elucidate the role of all kinds of fatty acid species in the body.

Effect of resveratrol on the hyperexcitability of nociceptive neurons associated with ectopic hyperalgesia induced by experimental tooth movement.

The present study investigated whether, under in vivo conditions, systemic administration of resveratrol attenuates the experimental tooth movement-induced ectopic hyperalgesia associated with hyperexcitability of nociceptive trigeminal spinal nucleus caudalis (SpVc) neurons. The threshold of escape from mechanical stimulation applied to the ipsilateral whisker pad in rats exposed to experimental tooth movement was significantly lower than seen in control rats from day 1 to 3 following movement of the right maxillary first molar tooth. The lowered mechanical threshold in the rats exposed to experimental tooth movement had almost returned to the level of sham-treated naïve rats at day 3 following administration of resveratrol. The mean mechanical threshold of nociceptive SpVc neurons was significantly lower after experimental tooth movement but the lower threshold could be reversed by administration of resveratrol. The higher discharge frequency of nociceptive SpVc neurons for noxious mechanical stimuli observed in rats exposed to experimental tooth movement was statistically significantly lower following resveratrol administration. These results suggest that resveratrol attenuates experimental tooth movement-induced mechanical ectopic hyperalgesia via suppression of peripheral and/or central sensitization. These findings support the idea that resveratrol, a complementary alternative medicine, is a potential therapeutic agent for the prevention of experimental tooth movement-induced ectopic hyperalgesia.

Characterization of ABC transporter genes, sll1180, sll1181, and slr1270, involved in acid stress tolerance of Synechocystis sp. PCC 6803.

Over 50 ATP-binding cassette (ABC) transporter-related genes are detected in the Synechocystis sp. PCC 6803 genome by genome sequence analysis. Deletion mutants of other substrate-unknown ABC transporter genes were screened for their acid stress sensitivities in a low-pH medium to identify ABC transporters involved in acid resistance. We found that a mutant of sll1180 encoding proteins with homology to HlyB in Escherichia coli (E.coli) is more sensitive to acid stress than wild-type (WT) cells and analyzed the abundance of expression of the genes in WT cells under acid stress condition by quantitative real-time reverse transcriptase-polymerase chain reaction. sll1180 expression increased in the WT cells after acid stress treatment. Immunofluorescence revealed that Sll1180 localized in the plasma membrane. These results suggest that Sll1180 has an important role in the growth of Synechocystis sp. PCC 6803 under acid stress conditions. HlyB, HlyD, and TolC complex transport HlyA in E.coli; therefore, we searched for genes corresponding to these in Synechocystis sp. PCC 6803. A BlastP search suggested that HlyA, HlyD, and TolC proteins had homology to Sll1951, Sll1181, and Slr1270. Therefore, we constructed deletion mutant of these genes. sll1181 and slr1270 mutant cells revealed acid stress sensitivity. The bacterial two-hybrid analysis showed that Sll1180 interacted with Sll1181 and Sll1951. Dot blot analysis of Sll1951-His revealed that the sll1180 and sll1181 mutant cells did not transport Sll1951-His from the cytoplasm to the extracellular matrix. These results suggest that Sll1180 and Sll1181 transport Sll1951 and that Sll1951-outside of the cells-might be a key factor in acid stress tolerance.

Effect of the Japanese diet during pregnancy and lactation or post-weaning on the risk of metabolic syndrome in offspring.

We examined the effects on offspring of ingestion of the 1975 Japanese diet during pregnancy and lactation and after weaning in mice. Pregnant dams were divided into groups that were fed the Japanese diet or a control diet and raised until offspring were weaned. The offspring after weaning were further divided into groups that were raised on the Japanese diet or the control diet. Ingestion of the Japanese diet after weaning suppressed accumulation of visceral fat in offspring, and reduced the amount of lipids in serum and liver. This effect was weakened if the Japanese diet was only ingested during pregnancy and lactation. Therefore, it was suggested that ingestion of the Japanese diet of mothers during pregnancy and lactation weakens the lipid accumulation inhibitory effect of the Japanese diet in children.

Effect of medium-chain triglycerides supplements and walking on health-related quality of life in sedentary, healthy middle-aged, and older adults with low BMIs: a randomized, double-blind, placebo-controlled, parallel-group trial.

Introduction: To extend individuals' healthy life expectancies, the improvement of subjective health and quality of life (QOL) has been increasingly prioritized, alongside the improvement of their physical functioning. Reports have indicated that intake of medium-chain triglycerides (MCTs) benefits the physical health of older individuals requiring nursing care, and athletes, and healthy individuals. But there are few studies investigating the effects of MCTs on subjective health and QOL. The present study sought to evaluate the combined effects of 12-week MCTs supplements and moderate-intensity walking exercise on the subjective health and QOL of middle-aged and older adults aged 60-74 with low BMIs (< 24 kg/m2) and who had no exercise habits. Methods: A placebo-controlled, double-blind, parallel-group trial was conducted. Three MCTs supplement groups with different doses and fatty acid compositions were compared with a control group. The study used the SF-36v2 questionnaire to assess subjective health and health-related QOL (HRQOL). Results: The result showed significant improvements in the scores on subscales of the physical QOL, such as Physical functioning and General health, and summary scores on the mental QOL, compared to the control. Conclusion: It is estimated that the combination of continuous intake of MCTs and walking exercise may affect HRQOL and improve subjective physical and mental health in sedentary, healthy, middle-aged and older adults. Clinical trial registration: https://rctportal.niph.go.jp/s/detail/um?trial_id=UMIN000046861, UMIN000046861.

A Randomized, Double-Blind, Controlled Trial Assessing If Medium-Chain Triglycerides in Combination with Moderate-Intensity Exercise Increase Muscle Strength in Healthy Middle-Aged and Older Adults.

An adequate nutritional intake is recommended for the prevention of physical frailty and sarcopenia. In particular, medium-chain fatty acids (MCFAs) are reportedly important for muscle strength in nursing home residents. However, the effects of MCFAs on healthy adults at risk for frailty remain unknown. Hence, a randomized, placebo-controlled study was conducted to investigate the effects of 12 weeks of medium-chain triglycerides (MCTs) intake and walking on muscle mass and function in healthy, sedentary, middle-aged and older adults with a low body mass index. Three MCT intake groups with different amounts of octanoic and decanoic acid intake were compared with a control group. After 12 weeks, knee extension strength increased in all groups, with the increases in all MCT intake groups being significantly higher than those in the control group (p < 0.05). Grip strength significantly increased from baseline in the MCT 6 g/day intake group (p < 0.05). The combination of aerobic exercise and MCT intake may be effective in preventing decline in muscle strength and promoting increase in muscle strength as they can improve muscle energy production, thereby contributing to the maintenance of good health for middle-aged and older adults at high risk for frailty and sarcopenia.

Incorporation of Dietary Arachidonic and Docosatetraenoic Acid into Mouse Brain.

It is essential to analyze the metabolism of dietary polyunsaturated fatty acids in the brain for the research and development of functional foods. In this study, a single dose of 2,2-dideuterium-labeled docosatetraenoic acid ((+2)DTA) or 2,2-dideuterium-labeled arachidonic acid ((+2)AA) was orally administered to Institute of Cancer Research (ICR) mice and its metabolism in the brain was investigated. In the (+2)DTA group, the (+2)DTA content in the brain was significantly increased at 4, 8, 24, and 96 h compared to 0 h after administration, while in the (+2)AA group, the (+2)AA content was significantly increased at 4, 8, 24, and 96 h compared to 0 h. However, there was no significant difference in the content of (+2)DTA, a metabolite of (+2)AA, among all the groups. These results suggest that dietary (+2)DTA and (+2)AA pass through the blood-brain barrier and dietary (+2)AA is rather stored in the brain than converted to (+2)DTA.

pspK acquisition contributes to the loss of capsule in pneumococci: molecular characterisation of non-encapsulated pneumococci.

With the introduction of the pneumococcal conjugate vaccine (PCV), the number of cases of non-vaccine type pneumococci and non-encapsulated Streptococcus pneumoniae (NESp) infection have increased. In order to clarify how pspK-harbouring NESp might have emerged, we characterised NESp and analysed the correlation between transformation and non-encapsulation. A total of 26 NESp strains were used in this study. The genetic backgrounds were compared using multilocus sequence typing (MLST). The ΔpspK::ermB strain, in which pspK was replaced by ermB in NESp, was constructed by homologous recombination. The genomic DNA of the ΔpspK::ermB strain was transformed into two types of encapsulated S. pneumoniae via transformation. The fitness of the parent and non-encapsulated transformants was compared using the growth curve. All NESp had pspK instead of capsular coding regions and were classified into 14 types by MLST, which indicated that NESp had several genetic backgrounds. Transformation of ΔpspK::ermB genomic DNA resulted in 10-4‒10-5 non-encapsulated transformants. Non-encapsulated transformants could grow faster than the encapsulated parent strain. The acquisition of pspK region via transformation contributed to the loss of encapsulation with high frequency. The present results suggest that non-encapsulation through pspK acquisition could be a potential mechanism to evade PCV.

Influence of Japanese diet consumption during pregnancy and lactation on lipid metabolism in offspring.

OBJECTIVE: Previous studies have demonstrated that obesity is rare among those who consume the Japanese diet because of its lower caloric content compared with the American diet. Meanwhile, it has been reported that maternal caloric restriction, which induces antiobesity effects, during pregnancy and lactation increases the likelihood of a low birthweight infant, which increases the risks for obesity and diabetes later in life. The aim of this study was to examine the influence of maternal consumption of the Japanese diet during pregnancy and lactation on the risk for obesity and diabetes in the offspring later in life. METHODS: Pregnant mice were divided into three groups and fed either a control diet, Western diet, or Japanese diet, and their offspring were raised until 7 wk old. RESULTS: Examinations of 18-d-old and 7-wk-old offspring showed no effect of consistently eating a Japanese diet during pregnancy and lactation on the health conditions of 18-d-old offspring, but 7-wk-old offspring showed a decrease in visceral fat and liver triacylglycerol levels. In addition, 7-wk-old offspring from mothers who consumed the Japanese diet during pregnancy and lactation showed a decrease in the homeostatic model assessment of insulin resistance and a reduced risk for developing diabetes. This tendency was also confirmed in 18-d-old offspring. Evaluation of the mechanism revealed that fatty acid synthesis in the liver of the offspring was suppressed by the mother's consumption of the Japanese diet. CONCLUSION: From these results, maternal consumption of the Japanese diet during pregnancy and lactation did not adversely affect the offspring, and continual intake of this diet reduced the risk for developing obesity and diabetes in the offspring later in life.

Impact of the introduction of a 13-valent pneumococcal vaccine on pneumococcal serotypes in non-invasive isolates from 2007 to 2016 at a teaching hospital in Japan.

PURPOSE: To prevent severe invasive pneumococcal infection, pneumococcal conjugate vaccines (PCVs) were introduced in Japan in 2010, and in 2013 a pneumococcal 13-valent conjugate vaccine (PCV13) was included in the routine vaccination schedule for infants. In this study, we analysed the antimicrobial susceptibilities and capsular types of pneumococci isolated from non-invasive patient sites from 2007 to 2016 to assess the impact of the introduction of PCV13. METHODOLOGY: A total of 618 pneumococcal isolates collected at a teaching hospital from 2007 to 2016 were used. These isolates were characterized by capsular typing, multilocus sequence typing and antimicrobial susceptibility testing. RESULTS: Capsular typing indicated that, after the introduction of the PCV, the proportion of PCV13 serotypes decreased (P<0.01), while non-PCV13 serotypes became diverse. In particular, increases in 22 F, 15A and 23A were noted among non-PCV13 serotypes. Regarding antimicrobial susceptibility, the non-susceptibility rate to penicillin of pneumococci that showed higher minimum inhibitory concentrations (MICs) than the susceptibility breakpoint decreased, and pneumococci tended to become susceptible. However, all type 23A pneumococci and 77.8  % of type 15A pneumococci showed the reverse trend, with low susceptibility to penicillin. Furthermore, all 15A and 23A isolates had macrolide resistance genes. CONCLUSION: These data suggest that PCVs can prevent infections caused by PCV serotypes. However, since non-PCV13-type pneumococci, in particular 15A and 23A, which have acquired multidrug resistance, have already emerged over time, the development of a novel vaccine targeting a broader spectrum of pneumococci is warranted.

K1 gene transformation activities in AIDS-related and classic type Kaposi's sarcoma: Correlation with clinical presentation.

Kaposi's sarcoma-associated herpesvirus (KSHV) causes both AIDS-related Kaposi's sarcoma (KS) and classic KS, but their clinical presentations are different, and respective mechanisms remain to be elucidated. The KSHV K1 gene is reportedly involved in tumorigenesis through the immunoreceptor tyrosine-based activation motif (ITAM). Since we found the sequence variations in the K1 gene of KSHV isolated from AIDS-related KS and classic KS, we hypothesized that the transformation activity of the K1 gene contributes to the different clinical presentations. To evaluate our hypothesis, we compared the transformation activities of the K1 gene between AIDS-related KS and classic KS. We also analyzed ITAM activities and the downstream AKT and NF-κB. We found that the transformation activity of AIDS-related K1 was greater than that of classic K1, and that AIDS-related K1 induced higher ITAM activity than classic K1, causing more potent Akt and NF-κB activities. K1 downregulation by siRNA in AIDS-related K1 expressing cells induced a loss of transformation properties and decreased both Akt and NF-κB activities, suggesting a correlation between the transformation activity of K1 and ITAM signaling. Our study indicates that the increased transformation activity of AIDS-related K1 is associated with its clinical aggressiveness, whereas the weak transformation activity of classic type K1 is associated with a mild clinical presentation and spontaneous regression. The mechanism of spontaneous regression of classic KS may provide new therapeutic strategy to cancer.

Transport of fluorescent chenodeoxycholic acid via the human organic anion transporters OATP1B1 and OATP1B3.

This study sought to clarify the contributions of organic anion-transporting polypeptide (OATP) 1B1 and 1B3 to the liver uptake of chenodeoxycholic acid (CDCA). We synthesized a fluorescent version of CDCA, chenodeoxychilyl-(Nepsilon-NBD)-lysine (CDCA-NBD), to characterize transporter-mediated uptake. CDCA-NBD is efficiently transported by OATP1B1 and OATP1B3 with high affinities. The Michaelis-Menten constants for CDCA-NBD uptake by OATP1B1 and OATP1B3 were 1.45 +/- 0.39 microM and 0.54 +/- 0.09 microM, respectively. By confocal laser scanning microscopy, CDCA-NBD, which is taken up by OATP1B1 and OATP1B3, was observed to localize to the cytosol. We also examined the transport of newly synthesized fluorescent bile acids. NBD-labeled bile acids, including cholic acid, deoxycholic acid, lithocholic acid, and ursodeoxycholic acid, were all transported by OATP1B1 and OATP1B3. CDCA-NBD exhibited the highest rate of transport of the five NBD-labeled bile acids examined in OATP1B1- and OATP1B3-expressing cells. Our results suggest that OATP1B1 and OATP1B3 play important roles in CDCA uptake into the liver. Fluorescent bile acids are useful tools to characterize the uptake properties of membrane transporters.