Publications by authors named "Isao Kobayashi"

126 Publications

Zinc-finger E-box-binding homeobox 1 (ZEB1) plays a crucial role in the maintenance of lung cancer stem cells resistant to gefitinib.

Thorac Cancer 2021 05 25;12(10):1536-1548. Epub 2021 Mar 25.

Department of Respiratory Medicine, Juntendo University, Graduate School of Medicine, Tokyo, Japan.

Background: Zinc-finger E-box-binding homeobox 1 (ZEB1) is an important regulator of epithelial-mesenchymal transition (EMT) and is involved in the maintenance of cancer stem cells (CSCs) via miR-200c and BMI1 pathway. Recent studies revealed that ZEB1 contributes to the EMT-mediated acquired resistance to gefitinib in EGFR-mutant non-small cell lung cancer (NSCLC). However, the precise role of ZEB1 in the maintenance of lung CSCs that lead to acquired resistance to gefitinib remains unclear.

Methods: PC9 and HCC827 NSCLC cell lines were treated with high concentrations of gefitinib, and surviving cells were referred to as "gefitinib-resistant persisters" (GRPs). ZEB1 knockdown or overexpression was performed to determine the biological significance of ZEB1 in the CSC features of GRPs, and animal models were studied for in vivo validation. Expression of ZEB1, BMI1, and ALDH1A1 was analyzed by immunohistochemistry in tumor specimens from NSCLC patients with acquired resistance to gefitinib.

Results: GRPs had characteristic features of mesenchymal and CSC phenotypes with high expression of ZEB1 and BMI1, and decreased miR-200c, in vitro and in vivo. ZEB1 silencing attenuated the suppression of miR-200c, resulting in the reduction in BMI1 and reversed the mesenchymal and CSC features of GRPs. Furthermore, ZEB1 overexpression induced EMT and increased the levels of CD133- and BMI1-positive GRPs in vitro and gefitinib resistance in vivo. Finally, ZEB1, BMI1, and ALDH1A1 were highly expressed in tumor specimens from EGFR-mutant NSCLC patients with gefitinib resistance.

Conclusions: ZEB1 plays an important role in gefitinib-resistant lung CSCs with EMT features via regulation of miR-200c and BMI1.
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http://dx.doi.org/10.1111/1759-7714.13937DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8107025PMC
May 2021

Spray technology applications of xanthan gum-based edible coatings for fresh-cut lotus root (Nelumbo nucifera).

Food Res Int 2020 11 19;137:109723. Epub 2020 Sep 19.

Tsukuba Life Science Innovation Program (T-LSI), University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8572, Japan; Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8572, Japan. Electronic address:

In this study, the effect of spraying method as an application technique for xanthan gum-based edible coatings was investigated, based on its barrier and microbial properties on fresh-cut lotus root. Xanthan gum solutions (0.1%, 0.3%, and 0.5%) were prepared and incorporated with 2% (w/w) citric acid as an anti-browning agent and 1% (w/w) glycerol as plasticizer. The coatings were then sprayed using a pilot spray system to 5 mm-thick slices of fresh-cut lotus root for 20 s, packed in polyethylene bags, stored for 16 d at 5 °C and analyzed for color, pH, morphology and microbial counts. It was found that spray-coated fresh-cut lotus root samples had significant reduction in the total color changes as compared to non-coated samples. The experimental results suggested that the spray coating treatments were effective in decreasing the enzymatic browning of fresh-cut lotus root during storage which could potentially increase its shelf-life in the market. In addition, we have also found that the xanthan gum-based spray coated treatments were also effective against inhibiting the growth of Bacillus subtilis during 24 h of incubation which were indicated by the lower microbial counts recorded as compared to non-coated fresh-cut lotus root samples. In this part of the work, the author highlighted the spray coating technique of xanthan gum-based edible coatings as a promising strategy in improving the storage stability of fresh-cut lotus root during post-harvest storage. Overall, the application of edible coatings is a promising strategy in extending the shelf life of fresh-cut lotus root. In the future, the author aims to widen the scope of the application of these coatings to other agricultural products which are prone to degradation during storage in the market.
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http://dx.doi.org/10.1016/j.foodres.2020.109723DOI Listing
November 2020

Tranilast Inhibits Pulmonary Fibrosis by Suppressing TGFβ/SMAD2 Pathway.

Drug Des Devel Ther 2020 29;14:4593-4603. Epub 2020 Oct 29.

Department of Respiratory Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan.

Purpose: Idiopathic pulmonary fibrosis (IPF) is characterized by the accumulation of extracellular matrix (ECM) protein in the lungs. Transforming growth factor (TGF) β-induced ECM protein synthesis contributes to the development of IPF. Tranilast, an anti-allergy drug, suppresses TGFβ expression and inhibits interstitial renal fibrosis in animal models. However, the beneficial effects of tranilast or its mechanism as a therapy for pulmonary fibrosis have not been clarified.

Methods: We investigated the in vitro effect of tranilast on ECM production and TGFβ/SMAD2 pathway in TGFβ2-stimulated A549 human alveolar epithelial cells, using quantitative polymerase chain reaction, Western blotting, and immunofluorescence. In vitro observations were validated in the lungs of a murine pulmonary fibrosis model, which we developed by intravenous injection of bleomycin.

Results: Treatment with tranilast suppressed the expression of ECM proteins, such as fibronectin and type IV collagen, and attenuated SMAD2 phosphorylation in TGFβ2-stimulated A549 cells. In addition, based on a wound healing assay in these cells, tranilast significantly inhibited cell motility, with foci formation that comprised of ECM proteins. Histological analyses revealed that the administration of tranilast significantly attenuated lung fibrosis in mice. Furthermore, tranilast treatment significantly reduced levels of TGFβ, collagen, fibronectin, and phosphorylated SMAD2 in pulmonary fibrotic tissues in mice.

Conclusion: These findings suggest that tranilast inhibits pulmonary fibrosis by suppressing TGFβ/SMAD2-mediated ECM protein production, presenting tranilast as a promising and novel anti-fibrotic agent for the treatment of IPF.
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http://dx.doi.org/10.2147/DDDT.S264715DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7605600PMC
August 2021

Microfibrillated cellulose from Argania spinosa shells as sustainable solid particles for O/W Pickering emulsions.

Carbohydr Polym 2021 Jan 29;251:116990. Epub 2020 Aug 29.

School of Integrative and Global Majors, Tsukuba Life Science Innovation Program, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan; Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan; Alliance for Research on Mediterranean and North Africa (ARENA), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan. Electronic address:

Microfibrillated cellulose (MFC) from Argan (Argania spinosa) shells was prepared by chemical purification of cellulose, then mechanical disintegration via high pressure homogenization was performed to isolate fibrils of cellulose. Chemical characterization of raw argan shell (AS-R), purified cellulose (AS-C), and argan shell MFC (AS-MFC) included FT-IR, XRD and NMR. Morphological characterization of AS-MFC was assessed using TEM. Next, the use of AS-MFC as oil-in-water (O/W) emulsions stabilizer was investigated. The particle concentration was observed to affect the long-term stability of the emulsions; high concentrations (0.5-1 % w/w) of AS-MFC resulted in emulsions that were thermodynamically stable during 15 days of storage, which was demonstrated by the droplet's size evolution. The suitable oil concentration for a maximum volume of emulsion using 1 % w/w AS-MFC was demonstrated. The results show that AS-MFC is able to stabilize 70 % w/w MCT oil without visual phase separation. Finally, CLSM shows the adsorption of AS-MFC at the oil-water interface and the formation of a 3D network surrounding oil droplets, confirming Pickering emulsion formation and stabilization.
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http://dx.doi.org/10.1016/j.carbpol.2020.116990DOI Listing
January 2021

Risk Factors of Subsequent Central Nervous System Tumors after Childhood and Adolescent Cancers: Findings from the French Childhood Cancer Survivor Study.

Cancer Epidemiol Biomarkers Prev 2021 01 8;30(1):133-141. Epub 2020 Oct 8.

Inserm U1018, CESP, Radiation Epidemiology Team, Gustave Roussy, Villejuif, Paris, France.

Background: Childhood or adolescent cancer survivors are at increased risks of subsequent primary neoplasms (SPN) of the central nervous system (CNS) after cranial irradiation. In a large multicentric cohort, we investigated clinical and therapeutic factors associated with the long-term risk of CNS SPN, and quantified the dose-response relationships.

Methods: We selected all CNS SPN cases diagnosed up to 2016 among members of the French Childhood Cancer Survivor Study at least 5 years after first cancer diagnosis in 1946-2000. Four controls per case were randomly selected within the cohort and matched by sex, year of/age at first cancer diagnosis, and follow-up time. On the basis of medical and radiological reports, cumulative radiation doses received to the SPN or matched location were retrospectively estimated using mathematical phantoms. We computed conditional logistic regression models.

Results: Meningioma risk significantly increased with higher radiation doses [excess OR per Gy (EOR/Gy) = 1.377; < 0.001; 86 cases; median latency time = 30 years], after adjustment for reported genetic syndromes and first CNS tumor. It was higher among youngest individuals at first cancer diagnosis, but did not vary with follow-up time. On the opposite, radiation-related glioma risk (EOR/Gy = 0.049; = 0.11; 47 cases; median latency time = 17 years) decreased over time ( for time effect = 0.05). There was a significant association between meningioma risk and cumulative doses of alkylating agents, but no association with growth hormone therapy.

Conclusions: The surveillance of patients with cranial irradiation should continue beyond 30 years after treatment.

Impact: The identified risk factors may inform long-term surveillance strategies.
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http://dx.doi.org/10.1158/1055-9965.EPI-20-0735DOI Listing
January 2021

Interfacial and emulsifying properties of purified glycyrrhizin and non-purified glycyrrhizin-rich extracts from liquorice root (Glycyrrhiza glabra).

Food Chem 2021 Feb 1;337:127949. Epub 2020 Sep 1.

Food and Medicinal Resource Engineering Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 5-2, Tsukuba City, Ibaraki 305-8565, Japan. Electronic address:

This study compared the interfacial and emulsifying properties of purified saponins and non-purified saponin-rich extracts of Glycyrrhiza glabra, and highlighted potential mechanisms by which crude surface-active compositions, such as liquorice root extract (LRE), act as emulsifiers. LRE presented different fluid properties, in comparison to purified glycyrrhizin (PG), at equivalent glycyrrhizin concentrations. Particularly, it exhibited limited glycyrrhizin fibrilization at pH < pKa and efficiently reduced the interfacial tension at the soybean oil/water interface, independently of pH. LRE also presented better emulsification properties, in comparison to PG samples. Emulsions prepared using LRE had lower droplet sizes when using higher oil mass fractions or lower homogenization pressures, which was attributed to 2 main factors: (i) efficient adsorption of glycyrrhizin molecules at relatively low interfacial curvatures, thus accelerating oil phase breakup during homogenization and (ii) sufficient coverage of newly generated droplets due to adsorption of residual surface-active components (e.g. proteins), thus minimizing droplet coalescence.
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http://dx.doi.org/10.1016/j.foodchem.2020.127949DOI Listing
February 2021

Melatonin suppresses both osteoblast and osteoclast differentiation through repression of epidermal Erk signaling in the zebrafish scale.

Biochem Biophys Res Commun 2020 10 5;530(4):644-650. Epub 2020 Aug 5.

Faculty of Biological Science and Technology, Institute of Science and Engineering, Kanazawa University, Kanazawa, Ishikawa, 920-1192, Japan. Electronic address:

Melatonin has been implicated in the regulation of bone metabolism; however, the molecular mechanisms underlying its involvement in fracture healing are still obscure. We previously developed an in vivo fracture healing model using the scale of a double-transgenic zebrafish, trap:GFP; osterix:mCherry, which labels osteoclasts and osteoblasts with GFP and mCherry, respectively. Here we show using this model that melatonin inhibits both osteoblast and osteoclast differentiation under fracture stress through the repression of Erk signaling in epidermal cells of the scale. Melatonin treatment resulted in reduced numbers of both osteoblasts and osteoclasts in the fractured scale. Immunochemistry analysis revealed that Erk signals in epidermal cells, which express melatonin receptors, were greatly enhanced in response to fracture stress, but this enhancement was blocked by melatonin treatment. Moreover, inhibition of Erk signaling phenocopied the effects of melatonin treatment in the fractured scale. Collectively, these data suggest that the activation of epidermal Erk signaling is required for both osteoblast and osteoclast differentiation in the early stage of fracture healing, and melatonin suppresses epidermal Erk signaling, leading to impaired fracture healing.
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http://dx.doi.org/10.1016/j.bbrc.2020.07.075DOI Listing
October 2020

Correction to: Establishment and characterization of novel cell lines derived from six lepidopteran insects collected in the field.

In Vitro Cell Dev Biol Anim 2020 Jun;56(6):492

Division of Insect Sciences, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), 1-2, Owashi, Tsukuba, 305-8634, Japan.

This article was originally published with the final word of the title, "field", omitted.
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http://dx.doi.org/10.1007/s11626-020-00470-5DOI Listing
June 2020

Uptake of osteoblast-derived extracellular vesicles promotes the differentiation of osteoclasts in the zebrafish scale.

Commun Biol 2020 04 23;3(1):190. Epub 2020 Apr 23.

Faculty of Biological Science and Technology, Institute of Science and Engineering, Kanazawa University, Kanazawa, Ishikawa, 920-1192, Japan.

Differentiation of osteoclasts (OCs) from hematopoietic cells requires cellular interaction with osteoblasts (OBs). Due to the difficulty of live-imaging in the bone, however, the cellular and molecular mechanisms underlying intercellular communication involved in OC differentiation are still elusive. Here, we develop a fracture healing model using the scale of trap:GFP; osterix:mCherry transgenic zebrafish to visualize the interaction between OCs and OBs. Transplantation assays followed by flow cytometric analysis reveal that most trap:GFP OCs in the fractured scale are detected in the osterix:mCherry fraction because of uptake of OB-derived extracellular vesicles (EVs). In vivo live-imaging shows that immature OCs actively interact with osterix:mCherry OBs and engulf EVs prior to convergence at the fracture site. In vitro cell culture assays show that OB-derived EVs promote OC differentiation via Rankl signaling. Collectively, these data suggest that EV-mediated intercellular communication with OBs plays an important role in the differentiation of OCs in bone tissue.
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http://dx.doi.org/10.1038/s42003-020-0925-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7181839PMC
April 2020

Establishment and characterization of novel cell lines derived from six lepidopteran insects collected in the field.

In Vitro Cell Dev Biol Anim 2020 Jun 3;56(6):425-429. Epub 2020 Apr 3.

Division of Insect Sciences, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), 1-2, Owashi, Tsukuba, 305-8634, Japan.

Insect cell lines are used to study cellular interactions and gene functions in vitro in several research areas. However, suitable cell lines for experiments are not always available, especially in non-model species. Here, we established novel cell lines derived from fat bodies of six lepidopteran insects: Cydia kurokoi (named NARO-Cyku), Cephonodes hylas (NARO-Cehy), Haritalodes basipunctalis (NARO-Haba), Theretra oldenlandiae (NARO-Thol), Lymantria dispar (NARO-Lydi), and Hyphantria cunea (NARO-Hycu) collected in the field. The larval fat body was a promising tissue for the starting material when samples were limited due to field collection. It was critical that the medium volume was kept to a minimum for primary culture to maintain adherence of the fat body cells to the flask. The flask was coated with poly-L-lysine for effective induction of adherence and cell division. The identities of cell lines were confirmed using DNA barcoding with the mitochondrial cytochrome c oxidase I gene after cultures were passaged over 50 times. All lines except for NARO-Lydi and NARO-Hycu are adherent cells, and population doubling time of six cell lines ranged from 1.03 to 2.49. Induction of gene expression was practicable in the four adherent cell lines as revealed by transfection of expression vectors and found the immediate early 2 and the Bombyx actin 3 were effective gene promoters. The results suggest that these cell lines are capable of gene functional analysis. Thus, establishments of cell line using our methods for non-model lepidopterans could make a practical contribution to pest management and insect utilization.
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http://dx.doi.org/10.1007/s11626-020-00438-5DOI Listing
June 2020

Impact of functional studies on exome sequence variant interpretation in early-onset cardiac conduction system diseases.

Cardiovasc Res 2020 11;116(13):2116-2130

Department of Cardiovascular Medicine, Kanazawa University Graduate School of Medical Sciences, 13-1, Takara-machi, Kanazawa, Ishikawa 920-8641, Japan.

Aims: The genetic cause of cardiac conduction system disease (CCSD) has not been fully elucidated. Whole-exome sequencing (WES) can detect various genetic variants; however, the identification of pathogenic variants remains a challenge. We aimed to identify pathogenic or likely pathogenic variants in CCSD patients by using WES and 2015 American College of Medical Genetics and Genomics (ACMG) standards and guidelines as well as evaluating the usefulness of functional studies for determining them.

Methods And Results: We performed WES of 23 probands diagnosed with early-onset (<65 years) CCSD and analysed 117 genes linked to arrhythmogenic diseases or cardiomyopathies. We focused on rare variants (minor allele frequency < 0.1%) that were absent from population databases. Five probands had protein truncating variants in EMD and LMNA which were classified as 'pathogenic' by 2015 ACMG standards and guidelines. To evaluate the functional changes brought about by these variants, we generated a knock-out zebrafish with CRISPR-mediated insertions or deletions of the EMD or LMNA homologs in zebrafish. The mean heart rate and conduction velocities in the CRISPR/Cas9-injected embryos and F2 generation embryos with homozygous deletions were significantly decreased. Twenty-one variants of uncertain significance were identified in 11 probands. Cellular electrophysiological study and in vivo zebrafish cardiac assay showed that two variants in KCNH2 and SCN5A, four variants in SCN10A, and one variant in MYH6 damaged each gene, which resulted in the change of the clinical significance of them from 'Uncertain significance' to 'Likely pathogenic' in six probands.

Conclusion: Of 23 CCSD probands, we successfully identified pathogenic or likely pathogenic variants in 11 probands (48%). Functional analyses of a cellular electrophysiological study and in vivo zebrafish cardiac assay might be useful for determining the pathogenicity of rare variants in patients with CCSD. SCN10A may be one of the major genes responsible for CCSD.
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http://dx.doi.org/10.1093/cvr/cvaa010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8453299PMC
November 2020

Oil-in-water emulsions containing tamarind seed gum during in vitro gastrointestinal digestion: rheological properties, stability, and lipid digestibility.

J Sci Food Agric 2020 Apr 17;100(6):2473-2481. Epub 2020 Feb 17.

Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Japan.

Background: Polysaccharides may enhance/inhibit lipid digestibility of oil-in-water (O/W) emulsions because of their emulsifying and/or stabilizing ability and can also affect the formation, stability, and viscosity of emulsions. Tamarind seed gum (TSG) was used as the sole emulsifier/stabilizer to stabilize an O/W emulsion prepared using high-speed homogenization. We investigated the effects of various TSG concentrations (50-150 g kg ) on the lipid digestibility, rheological properties, and stability of O/W emulsions during in vitro gastrointestinal digestion.

Results: A low concentration (50 g kg ) and a high concentration (150 g kg ) of TSG reduced lipid digestibility by about 33% and 45%, respectively, compared to the control sample (without TSG). However, the emulsion containing the intermediate TSG concentration at 100 g kg was the most efficient in the inhibition of lipid digestion, reducing lipid digestibility by about 70% compared to that of the control sample. The stability of emulsion tended to enhance as the concentration of TSG increased. The size of oil droplets before passing through the intestinal phase and the viscosity of the intestinal digested system may be important factors for enhancing/inhibiting lipid digestibility of emulsions. The destabilization of the emulsion during digestion was not clearly detected by rheological analysis because rheological characteristics (e.g. flow behavior index) were mainly driven by TSG.

Conclusions: The addition of TSG in O/W emulsions inhibited lipid digestibility. TSG at a concentration of 100 g kg was the most efficient in the inhibition of lipid digestibility, suggesting that TSG is an attractive alternative ingredient for control of lipid digestibility of emulsion foods. © 2020 Society of Chemical Industry.
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http://dx.doi.org/10.1002/jsfa.10268DOI Listing
April 2020

Dual role of Jam3b in early hematopoietic and vascular development.

Development 2020 01 8;147(1). Epub 2020 Jan 8.

Faculty of Biological Science and Technology, Institute of Science and Engineering, Kanazawa University, Ishikawa 920-1192, Japan.

In order to efficiently derive hematopoietic stem cells (HSCs) from pluripotent precursors, it is crucial to understand how mesodermal cells acquire hematopoietic and endothelial identities: two divergent, but closely related, cell fates. Although Npas4 has been recently identified as a conserved master regulator of hemato-vascular development, the molecular mechanisms underlying cell fate divergence between hematopoietic and vascular endothelial cells are still unclear. Here, we show in zebrafish that mesodermal cell differentiation into hematopoietic and vascular endothelial cells is regulated by Junctional adhesion molecule 3b (Jam3b) via two independent signaling pathways. Mutation of led to a reduction in expression in the posterior lateral plate mesoderm and defects in both hematopoietic and vascular development. Mechanistically, we show that Jam3b promotes endothelial specification by regulating expression through repression of the Rap1a-Erk signaling cascade. Jam3b subsequently promotes hematopoietic development, including HSCs, by regulating expression in endothelial precursors through the activation of an integrin-dependent signaling cascade. Our data provide insight into the divergent mechanisms for instructing hematopoietic or vascular fates from mesodermal cells.
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http://dx.doi.org/10.1242/dev.181040DOI Listing
January 2020

Influence of Smoking on Thyroid Function in Japanese Subjects: Longitudinal Study for One Year of On-Off Smoking.

J Endocr Soc 2019 Dec 3;3(12):2385-2396. Epub 2019 Oct 3.

Department of Internal Medicine, Division of Endocrinology and Metabolism, Gunma University Graduate School of Medicine, Maebashi, Japan.

Context: We previously identified factors affecting thyroid status, including sex, age, and smoking.

Objective: In the current study, we increased the number of subjects examined and investigated the effects of these factors, particularly smoking and the thyroid peroxidase antibody (TPO-Ab), in Japanese patients with euthyroxinemia and serum free T4 levels within the normal range.

Participants: A total of 12,289 subjects who underwent health checkups were analyzed in a cross-sectional and longitudinal study.

Results: The mean age of subjects was 50 ± 10 years (age range: 21 to 88 years). Serum TSH levels and the prevalence of positivity for TPO-Ab increased with age in Japanese subjects with euthyroxinemia. Mean serum TSH levels were significantly lower in the smoking group than in the nonsmoking group except for women older than 50 years. Serum TSH levels were significantly higher in subjects with positivity for TPO-Ab than in those with negativity at all ages and in both sexes; however, smoking did not affect free T4 levels or positivity for TPO-Ab. Among men, the rate of smokers was significantly higher in patients with subclinical hyperthyroidism (25%) than in those with subclinical hypothyroidism (10%; < 0.05). Furthermore, the results of the longitudinal study revealed a significant decrease in serum TSH levels 1 year after the start of smoking in men ( < 0.05).

Conclusion: Because smoking appeared to lower serum TSH levels in Japanese subjects with euthyroxinemia, their smoking status warrants careful consideration when evaluating subclinical thyroid function.
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http://dx.doi.org/10.1210/js.2019-00155DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6864365PMC
December 2019

Enrichment of hematopoietic stem/progenitor cells in the zebrafish kidney.

Sci Rep 2019 10 2;9(1):14205. Epub 2019 Oct 2.

Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA, USA.

Hematopoietic stem cells (HSCs) maintain the entire blood system throughout life and are utilized in therapeutic approaches for blood diseases. Prospective isolation of highly purified HSCs is crucial to understand the molecular mechanisms underlying regulation of HSCs. The zebrafish is an elegant genetic model for the study of hematopoiesis due to its many unique advantages. It has not yet been possible, however, to purify HSCs in adult zebrafish due to a lack of specific HSC markers. Here we show the enrichment of zebrafish HSCs by a combination of two HSC-related transgenes, gata2a:GFP and runx1:mCherry. The double-positive fraction of gata2a:GFP and runx1:mCherry (gata2a runx1) was detected at approximately 0.16% in the kidney, the main hematopoietic organ in teleosts. Transcriptome analysis revealed that gata2a runx1 cells showed typical molecular signatures of HSCs, including upregulation of gata2b, gfi1aa, runx1t1, pbx1b, and meis1b. Transplantation assays demonstrated that long-term repopulating HSCs were highly enriched within the gata2a runx1 fraction. In contrast, colony-forming assays showed that gata2a runx1 cells abundantly contain erythroid- and/or myeloid-primed progenitors. Thus, our purification method of HSCs in the zebrafish kidney is useful to identify molecular cues needed to regulate self-renewal and differentiation of HSCs.
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http://dx.doi.org/10.1038/s41598-019-50672-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6775131PMC
October 2019

Fucoxanthin-Loaded Oil-in-Water Emulsion-Based Delivery Systems: Effects of Natural Emulsifiers on the Formulation, Stability, and Bioaccessibility.

ACS Omega 2019 Jun 18;4(6):10502-10509. Epub 2019 Jun 18.

Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan.

The effect of natural emulsifiers (whey protein isolate, WPI; modified lecithin, ML; and gum arabic, GA) on the formulation, stability, and bioaccessibility of fucoxanthin-loaded oil-in-water (O/W) emulsions was determined in this study. The fine emulsions were prepared under high-pressure homogenization at 100 MPa for 4 passes, using 2 wt % WPI, ML, and GA, resulting in emulsions with the droplet sizes of 136, 140, and 897 nm, respectively. The chemical stability of fucoxanthin in the emulsions after long-term storage at ambient temperature decreased in the following order: WPI > GA > ML. The release of free fatty acids of fucoxanthin, studied by in vitro digestion, decreased in the following order: WPI > ML > GA > bulk oil. The bioaccessibility of fucoxanthin in emulsions stabilized by WPI, ML, and GA after in vitro digestion were 92.5 ± 6.8%, 44.6 ± 0.4, and 36.8 ± 2.5, respectively. These results indicate that natural emulsifier type and concentration used significantly affects the formulation, stability, lipid digestion, and fucoxanthin bioaccessibility, which may be ascribed to the different properties of each emulsifier. The bioaccessibility of fucoxanthin was improved by using emulsion-based delivery systems.
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http://dx.doi.org/10.1021/acsomega.9b00871DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6648090PMC
June 2019

Role of FBXW7 in the quiescence of gefitinib-resistant lung cancer stem cells in EGFR-mutant non-small cell lung cancer.

Bosn J Basic Med Sci 2019 Nov 8;19(4):355-367. Epub 2019 Nov 8.

Department of Respiratory Medicine; Research Institute for Diseases of Old Ages, Graduate School of Medicine, Juntendo University, Tokyo, Japan.

Several recent studies suggest that cancer stem cells (CSCs) are involved in intrinsic resistance to cancer treatment. Maintenance of quiescence is crucial for establishing resistance of CSCs to cancer therapeutics. F-box/WD repeat-containing protein 7 (FBXW7) is a ubiquitin ligase that regulates quiescence by targeting the c-MYC protein for ubiquitination. We previously reported that gefitinib-resistant persisters (GRPs) in EGFR-mutant non-small cell lung cancer (NSCLC) cells highly expressed octamer-binding transcription factor 4 (Oct-4) as well as the lung CSC marker CD133, and they exhibited distinctive features of the CSC phenotype. However, the role of FBXW7 in lung CSCs and their resistance to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors in NSCLC is not fully understood. In this study, we developed GRPs from the two NSCLC cell lines PC9 and HCC827, which express an EGFR exon 19 deletion mutation, by treatment with a high concentration of gefitinib. The GRPs from both PC9 and HCC827 cells expressed high levels of CD133 and FBXW7, but low levels of c-MYC. Cell cycle analysis demonstrated that the majority of GRPs existed in the G0/G1 phase. Knockdown of the FBXW7 gene significantly reduced the cell number of CD133-positive GRPs and reversed the cell population in the G0/G1-phase. We also found that FBXW7 expression in CD133-positive cells was increased and c-MYC expression was decreased in gefitinib-resistant tumors of PC9 cells in mice and in 9 out of 14 tumor specimens from EGFR-mutant NSCLC patients with acquired resistance to gefitinib. These findings suggest that FBXW7 plays a pivotal role in the maintenance of quiescence in gefitinib-resistant lung CSCs in EGFR mutation-positive NSCLC.
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http://dx.doi.org/10.17305/bjbms.2019.4227DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6868484PMC
November 2019

Rap1b Promotes Notch-Signal-Mediated Hematopoietic Stem Cell Development by Enhancing Integrin-Mediated Cell Adhesion.

Dev Cell 2019 06 18;49(5):681-696.e6. Epub 2019 Apr 18.

Department of Molecular Pathophysiology, Institute of Advanced Medical Sciences, Nippon Medical School, 1-396 Kosugi-machi, Nakahara-ku, Kawasaki, Kanagawa 211-8533, Japan. Electronic address:

Hematopoietic stem cells (HSCs) emerge from hemogenic endothelium (HE) within the ventral portion of the dorsal aorta during vertebrate development. In zebrafish, Notch signaling induces HE specification from posterior lateral plate mesoderm (PLPM) cells as they migrate over the ventral surface of the somite. During migration, PLPM cells make close contact with Notch-ligand-expressing somitic cells to acquire HE identity. Herein, we show in zebrafish that the small GTPase Rap1b regulates HSC development by potentiating Notch-mediated HE specification. PLPM cells migrate toward the midline along the somite boundary where fibronectin accumulates. Rap1b stimulates integrin β1 to enhance PLPM cell adhesion to fibronectin localized at the somite boundary. Rap1b-induced integrin-β1-mediated adhesion to fibronectin leads to the spreading of PLPM cells to facilitate their physical contact with the Notch-ligand-expressing somitic cells, thereby promoting Notch-mediated HE specification. Thus, we have revealed an unexpected role of Rap1-induced integrin-mediated cell adhesion in HSC development.
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http://dx.doi.org/10.1016/j.devcel.2019.03.023DOI Listing
June 2019

Age-Dependent Progression of Renal Dysfunction After Adrenalectomy for Aldosterone-Producing Adenomas in Japan.

J Endocr Soc 2019 Mar 17;3(3):577-589. Epub 2018 Dec 17.

Department of Internal Medicine, Division of Endocrinology and Metabolism, Gunma University Graduate School of Medicine, Maebashi, Japan.

Context: In patients with aldosterone-producing adenomas (APAs), adrenalectomy causes a rapid decrease in blood pressure and increase in blood potassium levels; however, the effects of these intensive metabolic changes on kidney function with age have not yet been examined in Japan.

Objective: To investigate factors related to the progression of kidney dysfunction after adrenalectomy in different age groups.

Participants: Fifty Japanese patients with APAs and 27,572 health checkup patients as controls were examined.

Main Outcome Measures: We investigated changes in estimated glomerular filtration rate (eGFR) after adrenalectomy and characterized patients who progressed to chronic kidney disease (CKD).

Results: The postoperative cutoff age of CKD is 50 years and age is a unique factor for the progression of CKD after adrenalectomy. Among preoperative patients, CKD was 6% for those <50 years old and 40% for those ≥50 years old, indicating a higher prevalence of CKD with APAs than in control subjects. Median eGFR <50 mL/min/1.73 m did not significantly change after adrenalectomy but decreased from 67 to 42 mL/min/1.73 m in those with APAs ≥50 years old. Patients with APAs ≥50 years old who progressed to CKD showed higher preoperative aldosterone/renin ratios, lower potassium and chloride levels, lower body mass index, and a higher incidence of a history of cardiovascular events and KCNJ5 mutation rates.

Conclusion: Age is the most important predictor of the progression of kidney dysfunction after adrenalectomy in Japanese patients with APAs, particularly those with a history of cardiovascular events and positivity for KCNJ5 mutations.
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http://dx.doi.org/10.1210/js.2018-00260DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6382408PMC
March 2019

Resistant Starch Attenuates Bone Loss in Ovariectomised Mice by Regulating the Intestinal Microbiota and Bone-Marrow Inflammation.

Nutrients 2019 Jan 30;11(2). Epub 2019 Jan 30.

Department of Food Function and Labeling, National Institute of Health and Nutrition, National Institutes of Biomedical Innovation, Health and Nutrition, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8636, Japan.

The intestinal microbiota may regulate bone metabolism by reducing levels of pro-inflammatory cytokines, and T cells in bone tissues of oestrogen-deficient mice have been reported. Resistant starch (RS) is a type of dietary fibre and results in changes in the composition of the gut microbiota. We evaluated the effects of RS supplemented in diets on intestinal microbial composition, bone mineral density, and inflammatory-gene expression in the colon and bone marrow of ovariectomised (OVX) mice. OVX mice were divided randomly into three groups: OVX control, OVX fed a 20% high amylose corn starch (HAS) diet, and OVX fed a 20% acid-hydrolysed HAS (AH-HAS) diet. HAS and AH-HAS diets contained 6.8% and 12% of RS, respectively. After 6 weeks, treatment with HAS or AH-HAS increased the abundance of spp. in faeces. The AH-HAS diet tended to upregulate mRNA expression of interleukin (IL)-10 in the colon, and downregulate expression of receptor activator of nuclear factor kappa-B ligand and IL-7 receptor genes in the bone marrow of OVX mice. AH-HAS treatment attenuated ovariectomy-induced bone loss. These findings suggest that AH-HAS might change the microbiota and immune status of the bone marrow, resulting in attenuated bone resorption in OVX mice.
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http://dx.doi.org/10.3390/nu11020297DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6412451PMC
January 2019

Anteroposterior molecular registries in ectoderm of the echinus rudiment.

Dev Dyn 2018 12 22;247(12):1297-1307. Epub 2018 Nov 22.

Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa, Japan.

Background: Echinoderms and hemichordates are sister taxa that both have larvae with tripartite coeloms. Hemichordates inherit the coelom plan and ectoderm from larvae, whereas echinoderms form the adult rudiment comprising rearranged coeloms and a vestibule that then develops into adult oral ectoderm. Molecular networks that control patterns of the ectoderm and the central nervous system along the anteroposterior (AP) axis are highly conserved between hemichordates and chordates, respectively. In echinoderms, however, little is known about the AP registry in the ectoderm.

Results: We isolated ectodermal AP map genes from the sand dollar Peronella japonica and examined their expression. Comparative expression analyses showed that (1) P. japonica orthologs of hemichordate anterior markers are expressed in the larval apical plate, which degenerates during metamorphosis; (2) P. japonica orthologs of the medial markers are expressed in the ambulacral ectoderm of the rudiment; and (3) few P. japonica orthologs of the posterior markers are expressed in ectoderm.

Conclusions: We suggest that echinoids only inherit the ambulacral ectoderm from a common ambulacrarian ancestor, which largely corresponds to the collar ectoderm in hemichordates. The ectodermal AP registry provides insights into the AP axis and evolutionary processes of echinoderms from a common ambulacrarian ancestor. Developmental Dynamics 247:1297-1307, 2018. © 2018 Wiley Periodicals, Inc.
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http://dx.doi.org/10.1002/dvdy.24686DOI Listing
December 2018

[Construction of a Platform for the Development of Pharmaceutical and Medical Applications Using Transgenic Silkworms].

Yakugaku Zasshi 2018 ;138(7):863-874

Institute of Agrobiological Sciences, National Agriculture and Food Research Organization.

 We have been constructing a platform for the development of pharmaceutical and medical applications using the domesticated silkworm, Bombyx mori, as a new animal model for drug development and evaluation. Because silkworm larvae originally have the capacity to synthesize up to 0.5 g of silk proteins, genetically modified silkworms (transgenic silkworms) are expected to have high potential in the production of recombinant silks/proteins. An innovative method for generating transgenic silkworms was established in 2000, and ever since this epoch-defining technological development, longstanding efforts have succeeded in developing novel silks that enable the manufacture of new textile materials for regenerative medical uses. Furthermore, we have succeeded in developing a new system of recombinant protein production. This recombinant protein production system is currently capable of producing a maximum of approximately 15 mg recombinant protein per silkworm larva. Transgenic silkworms have also been shown to produce a wide variety of useful proteins, including antibodies and membrane proteins. Some of these recombinant proteins have been in commercial use since 2011. In addition, we have been developing transgenic silkworms as a novel animal model for testing medicines based on metabolic similarities between silkworms and mammals. These applications show the suitability and potential of transgenic silkworms for medical use. Here, we will describe the challenges faced in creating a transgenic silkworm-based platform for pharmaceutical and medical applications.
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http://dx.doi.org/10.1248/yakushi.17-00202-1DOI Listing
August 2018

RANKL, Ephrin-Eph and Wnt10b are key intercellular communication molecules regulating bone remodeling in autologous transplanted goldfish scales.

Comp Biochem Physiol A Mol Integr Physiol 2018 11 15;225:46-58. Epub 2018 Jun 15.

Department of Clinical Laboratory Science, Graduate School of Medical Science, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan. Electronic address:

This study aimed to investigate the precise data of gene expression, functions, and chronological relationships amongst communication molecules involved in the bone remodeling process with an in vivo model using autologous transplanted scales of goldfish. Autotransplantation of methanol-fixed cell-free scales triggers scale resorption and regeneration, as well as helps elucidate the process of bone remodeling. We investigated osteoclastic markers, osteoblastic markers, and gene expressions of communicating molecules (RANKL, ephrinB2, EphB4, EphA4, Wnt10b) by qPCR, in situ hybridization for Wnt10b, and immunohistochemistry for EphrinB2 and EphA4 proteins to elucidate the bone remodeling process. Furthermore, functional inhibition experiments for the signaling of ephrinB2/Eph, ephrin/EphA4, and Wnt10b using specific antibodies, revealed that these proteins are involved in key signaling pathways promoting normal bone remodeling. Our data suggests that the remodeling process comprises of two successive phases. In the first absorption phase, differentiation of osteoclast progenitors by RANKL is followed by the bone absorption by mature, active osteoclasts, with the simultaneous induction of osteoblast progenitors by multinucleated osteoclast-derived Wnt10b, and proliferation of osteoblast precursors by ehprinB2/EphB4 signaling. Subsequently, during the second formation phase, termination of bone resorption by synergistic cooperation occurs, with downregulation of RANKL expression in activated osteoblasts and Ephrin/EphA4-mediated mutual inhibition between neighboring multinucleated osteoclasts, along with simultaneous activation of osteoblasts via forward and reverse EphrinB2/EphB4 signaling between neighboring osteoblasts. In addition, the present study shows that autologous transplantation of methanol-fixed cell-free scale is an ideal in vivo model to study bone remodeling.
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http://dx.doi.org/10.1016/j.cbpa.2018.06.011DOI Listing
November 2018

Microencapsulation of betanin in monodisperse W/O/W emulsions.

Food Res Int 2018 07 25;109:489-496. Epub 2018 Apr 25.

Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil. Electronic address:

Betanin is the main pigment of the food color beetroot red (E162). Due to the fair heat and light stability of E162, this pigment is mainly used in minimally processed packaged food products. Encapsulation increases the stability of betanin, but detailing on the effect of different sources of betanin on the properties and stability of multiple emulsions are scarce. Here we describe the encapsulation of E162, spray-dried beetroot juice and betanin in a monodisperse food-grade water-in-oil-in-water (W/O/W) emulsions by using microchannel emulsification. We compare the tinctorial strength of the encapsulated pigments and investigate the effect of temperature, storage period and pigment concentration on emulsion stability and color. Betanin increases the overall stability of the W/O/W emulsion, reduce the oil droplet size and improve size distribution when compared to the negative control without pigment and to emulsions containing betanin from other sources.
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http://dx.doi.org/10.1016/j.foodres.2018.04.053DOI Listing
July 2018

A single amino acid substitution in the Bombyx-specific mucin-like membrane protein causes resistance to Bombyx mori densovirus.

Sci Rep 2018 05 9;8(1):7430. Epub 2018 May 9.

Division of Insect Sciences, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, 305-8634, Japan.

Bombyx mori densovirus type 1 (BmDV) is a pathogen that causes flacherie disease in the silkworm. The absolute nonsusceptibility to BmDV among certain silkworm strains is determined independently by two genes, nsd-1 and Nid-1. However, neither of these genes has been molecularly identified to date. Here, we isolated the nsd-1 gene by positional cloning and characterized the properties of its product, NSD-1. Sequence and biochemical analyses revealed that this gene encodes a Bombyx-specific mucin-like glycoprotein with a single transmembrane domain. The NSD-1 protein was specifically expressed in the larval midgut epithelium, the known infection site of BmDV. Sequence analysis of the nsd-1 gene from 13 resistant and 12 susceptible strains suggested that a specific arginine residue in the extracellular tail of the NSD-1 protein was common among susceptible strains. Germline transformation of the susceptible-type nsd-1 (with a single nucleotide substitution) conferred partial susceptibility to resistant larvae, indicating that the +  gene is required for the susceptibility of B. mori larvae to BmDV and the susceptibility is solely a result of the substitution of a single amino acid with arginine. Taken together, our results provide striking evidence that a novel membrane-bound mucin-like protein functions as a cell-surface receptor for a densovirus.
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http://dx.doi.org/10.1038/s41598-018-25388-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5943349PMC
May 2018

Formulation and characterization of water-in-oil nanoemulsions loaded with açaí berry anthocyanins: Insights of degradation kinetics and stability evaluation of anthocyanins and nanoemulsions.

Food Res Int 2018 04 17;106:542-548. Epub 2018 Jan 17.

Tsukuba Life Science Innovation Program (T-LSI), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan; Food Research Institute, NARO, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan. Electronic address:

Açaí berry is the fruit of an Amazonian palm tree and rich in anthocyanins (ACNs). Scientific studies have proven the health benefits of açaí berry and declared this fruit as "super fruit". ACNs have high antioxidant activities, but they are unstable and can easily deteriorate during food processing. In order to protect ACNs and increase their applicability, food-grade water-in-oil (W/O) emulsions were successfully formulated with different concentrations of açaí berry extracts (AEs). The formulated W/O nanoemulsions were relatively stable, with no phase separation after 30 days of storage. The average droplet size varied between 146.8 and 814.8 nm, with higher values corresponding to samples without AEs. All W/O nanoemulsion samples exhibited antioxidant activity and high retention rates of polyphenols after 30 days of storage. ACN retention followed first-order kinetics, with high protection of ACNs observed in emulsified samples. 2% AE encapsulated in a 30 wt% W/O nanoemulsion had an estimated half-life of 385 days. The results indicate that stable nanoemulsion systems with high ACN protection can be produced with possible applications in the food and pharmaceutical industries.
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http://dx.doi.org/10.1016/j.foodres.2018.01.017DOI Listing
April 2018

Formulation and stabilization of oil-in-water nanoemulsions using a saponins-rich extract from argan oil press-cake.

Food Chem 2018 Apr 6;246:457-463. Epub 2017 Dec 6.

Tsukuba Life Science Innovation Program (T-LSI), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan. Electronic address:

In this study, we formulated and stabilized oil-in-water nanoemulsions using a crude extract from argan press-cake as sole emulsifier. Various extracts from argan press-cake were prepared in order to select the most surface-active one(s) foreseeing emulsions preparation. Fifty percent (v/v) ethanolic extract reduced the interfacial tension to a minimum value at both MCT oil and soybean oil interfaces (12.7 and 10.5 mN m respectively). This extract was also effective at producing fine emulsions with small droplet sizes (d < 115 nm) and good physical stability using different oils such as soybean oil, MCT oil and fish oil and at conventional homogenization conditions (100 MPa for 4 passes). On the other hand, the emulsions were very sensitive to NaCl addition (≥25 mM) and to acidic pH (<3) indicating that the main stabilization mechanism is electrostatic, likely due to the presence of surface-active compounds with ionizable groups such as saponins.
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http://dx.doi.org/10.1016/j.foodchem.2017.12.008DOI Listing
April 2018

Formulation and characterization of O/W nanoemulsions encapsulating high concentration of astaxanthin.

Food Res Int 2017 12 16;102:364-371. Epub 2017 Jun 16.

Centre for Chemistry and Biotechnology, Deakin University, Waurn Ponds, Victoria 3217, Australia. Electronic address:

This study evaluates the effect of modified lecithin (ML) and sodium caseinate (SC) on the formulation, stability and bioaccessibility of astaxanthin (AXT) loaded oil-in-water (O/W) nanoemulsions. These nanoemulsions were formulated using high-pressure homogenization in four passes at 100MPa. The volume mean diameter (d) of nanoemulsions produced by ML and SC were 163±5 and 144±12 nm, respectively. The physiochemical stability of nanoemulsions was recorded at 25°C. The nanoemulsions prepared by ML were stable for 30 minutes against a wide range of pH and heating temperatures (60-120 °C). However, ML-stabilized nanoemulsions showed droplet growth when treated at high NaCl concentrations. In comparison, droplet growth was observed in SC-stabilized nanoemulsions at pH4 and at high temperature treatment. However, SC-stabilized nanoemulsions were stable at high NaCl concentration (500 mM). The SC-stabilized nanoemulsions showed good physical and chemical stability (>70%) after 30 days of storage. The bioaccessibility of AXT in nanoemulsions was significantly higher in ML (33%) than in SC-stabilized nanoemulsions (6%), indicating a strong influence of emulsifier on bioaccessibility. These findings provide valuable information in designing nutritional products such as aqueous based AXT fortified beverages.
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http://dx.doi.org/10.1016/j.foodres.2017.06.019DOI Listing
December 2017

Formulation and stability assessment of ergocalciferol loaded oil-in-water nanoemulsions: Insights of emulsifiers effect on stabilization mechanism.

Food Res Int 2016 Dec 18;90:320-327. Epub 2016 Oct 18.

Tsukuba Life Science Innovation Program (TSLI), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan; Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan; Food Research Institute, NARO, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan. Electronic address:

In the study, we investigated the effect of emulsifiers with different stabilizing mechanisms on the formulation and stability of ergocalciferol loaded oil-in-water (O/W) emulsions. O/W emulsion stabilized by modified lecithin (ML; electrostatic stabilization), sodium caseinate (SC; electrosteric stabilization) or decaglycerol monooleate (MO-7S; steric stabilization) were formulated using high-pressure homogenization. The Sauter mean diameter (d) of emulsions produced by ML, SC and MO-7S were 126±1, 127±4 and 138±3nm, respectively. The stability of resulting emulsions was evaluated when they exposed to different environmental stresses and during 30days of storage at 25 and 55°C. Results showed that the emulsions prepared by MO-7S or ML were stable against a wide range of pH (2-8), while SC-stabilized emulsions showed instability with extensive droplet aggregation at pH4 or and 5. Only ML-stabilized emulsions showed droplet growth due to coalescence when treated at high NaCl concentration (300-500mM). In the absence of glucose, SC-stabilized O/W emulsions showed better freeze-thaw stability, in comparison to those formed with ML or MO-7S emulsifiers. The emulsion produced by ML was found to be stable to droplet aggregation at heating temperatures (80-120°C) for 1h. All the O/W emulsions stored at 25°C showed good physical and chemical stability. However, the chemical stability of ergocalciferol in emulsion system decreased in order of ML>MO-7S≫SC during storage at 55°C for a period of 30days. These findings provide valuable information for the development of nanoemulsion-based delivery system applied in food and beverage products.
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http://dx.doi.org/10.1016/j.foodres.2016.10.021DOI Listing
December 2016

Formulation and characterization of O/W emulsions stabilized using octenyl succinic anhydride modified kudzu starch.

Carbohydr Polym 2017 Nov 18;176:91-98. Epub 2017 Aug 18.

Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8572, Japan; Tsukuba Life Science Innovation Program (TLSI), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan; Food Research Institute, NARO, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan. Electronic address:

Kudzu starch esterified with octenyl succinic anhydride (OSA) was used as a food-grade emulsifier to formulate O/W emulsions. In addition, the difference between the physicochemical properties and emulsifying ability of native kudzu starch and those of OSA-modified kudzu starch was investigated. Granules of the OSA-modified kudzu starches increased in size after gelatinization. The interfacial tension between soybean oil and gelatinized OSA-modified kudzu starch was lower than that of kudzu starch. The droplet size of O/W emulsions decreased to 186nm at 100MPa after three passes. The emulsions stabilized using gelatinized OSA-modified kudzu starch were less stable when exposed to different ionic strengths (100mM to 500mM NaCl), than when exposed to different pH levels (2-8). The results of oil droplet size and confocal laser scanning microscopy analysis indicated that emulsions containing 2-5% OSA-modified kudzu starch remained stable at room temperature for 30 days.
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http://dx.doi.org/10.1016/j.carbpol.2017.08.064DOI Listing
November 2017
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