Mannosidase-inhibiting iminosugar production by recombinant Corynebacterium glutamicum harboring the 1-deoxynojirimycin biosynthetic gene cluster.

The iminosugar class of carbohydrate-active enzyme inhibitors has therapeutic applications in metabolic syndrome conditions, viral infections and cancer. Compared to chemical synthesis, microbial iminosugar production has benefits of cost, sustainability and optimization. In this study, the 1-deoxynojirimycin (DNJ) biosynthetic gene cluster from Bacillus velezensis MBLB0692, and its individual genes, were cloned into Corynebacterium glutamicum (Cg). Characterizations of the encoded aminotransferase GabT1, phosphatase Yktc1, and dehydrogenase GutB1, were performed with purified enzymes and whole cell biocatalysts bearing individual and clustered (TYB) genes. GabT1 showed a variable pattern in its half-reaction with a slow turnover. GutB1 was an alkaline dehydrogenase with a broad substrate specificity and no divalent ion dependency while the zinc-dependent phosphatase Yktc1 had substrate specificity that was both pH- and ion-dependent. The CgYktc1 and CgGutB1 whole cells were viable biocatalysts with wider ranges of substrates than their enzyme counterparts. The CgTYB cells produced mannosidase-inhibiting iminosugars corresponding to mannojirimycin dehydrate (162 m/z) and deoxymannojirimycin (164 m/z). Mannosidase inhibitors have been found to be effective in treating orphan diseases, cancer and viral infections, and their biosynthesis by recombinant C. glutamicum can be optimized for industrial production and novel drug development.

Correction to: A combined extract containing Schisandra chinensis (SCE) reduced hepatic triglyceride accumulation in rats fed a high­sucrose diet.

[This corrects the article DOI: 10.1007/s10068-023-01464-1.].

High Mobility Transistors and Flexible Optical Synapses Enabled by Wafer-Scale Chemical Transformation of Pt-Based 2D Layers.

Electronic devices employing two-dimensional (2D) van der Waals (vdW) transition-metal dichalcogenide (TMD) layers as semiconducting channels often exhibit limited performance (e.g., low carrier mobility), in part, due to their high contact resistances caused by interfacing non-vdW three-dimensional (3D) metal electrodes. Herein, we report that this intrinsic contact issue can be efficiently mitigated by forming the 2D/2D in-plane junctions of 2D semiconductor channels seamlessly interfaced with 2D metal electrodes. For this, we demonstrated the selectively patterned conversion of semiconducting 2D PtSe2 (channels) to metallic 2D PtTe2 (electrodes) layers by employing a wafer-scale low-temperature chemical vapor deposition (CVD) process. We investigated a variety of field-effect transistors (FETs) employing wafer-scale CVD-2D PtSe2/2D PtTe2 heterolayers and identified that silicon dioxide (SiO2) top-gated FETs exhibited an extremely high hole mobility of ∼120 cm2 V-1 s-1 at room temperature, significantly surpassing performances with previous wafer-scale 2D PtSe2-based FETs. The low-temperature nature of the CVD method further allowed for the direct fabrication of wafer-scale arrays of 2D PtSe2/2D PtTe2 heterolayers on polyamide (PI) substrates, which intrinsically displayed optical pulse-induced artificial synaptic behaviors. This study is believed to vastly broaden the applicability of 2D TMD layers for next-generation, high-performance electronic devices with unconventional functionalities.

A combined extract containing Schisandra chinensis (SCE) reduced hepatic triglyceride accumulation in rats fed a high-sucrose diet.

Excessive hepatic lipid accumulation is closely linked to inflammation, insulin resistance, and metabolic syndromes. We hypothesized that a combined extract containing Schisandra chinensis (SCE) could alleviate hepatic lipid accumulation. Male Sprague-Dawley rats fed a high-sucrose diet (HSD) were randomly assigned to three groups (n = 6): normal diet (ND), HSD (60% kcal from sucrose), and HSD + SCE (HSD with 2.44% SCE). Liquid chromatography-tandem mass spectrometry revealed that SCE contains chlorogenic acid (5.514 ± 0.009 mg/g) and schisandrin (0.179 ± 0.002 mg/g) as bioactive components. SCE did not alter the body weight, fat mass, lean mass, or glucose levels. Strikingly, SCE effectively reduced the plasma triglyceride (TG) and hepatic TG levels compared to the HSD group. Adiposity reduction is due to decreased activity of hepatic de novo lipogenic enzymes. These results indicated that SCE has nutraceutical potential for the prevention and treatment of hepatic steatosis. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-023-01464-1.

Development of performance indicators by the Delphi study for foodservice operations in senior welfare centers: application of the balanced scorecard.

With the rapid growth of the elderly population, the number of elderly welfare centers has expanded significantly. However, the current regulations and standards for foodservice management in these centers are inadequate. To address this issue, this study aimed to develop objective and integrated performance indicators based on the Balanced Scorecard for foodservice programs in elderly welfare centers. To evaluate the validity and reliability of the performance indicators, two Delphi studies were conducted in April 2017. The Delphi survey included the evaluation of strategic goals, financial perspective, customer perspective, learning and growth perspective, and the internal process perspective. The degree of consensus among experts was assessed using Kendall's W-test. As a result of the study, the study ultimately identified 33 performance indicators from 12 strategic goals in four perspectives, which could be used as an efficient tool to evaluate, supplement, and improve foodservice in elderly welfare centers. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-023-01468-x.

Efficient biotransformation of naringenin to naringenin α-glucoside, a novel α-glucosidase inhibitor, by amylosucrase from Deinococcus wulumuquiensis.

Amylosucrase (ASase) efficiently biosynthesizes α-glucoside using flavonoids as acceptor molecules and sucrose as a donor molecule. Here, ASase from Deinococcus wulumuqiensis (DwAS) biosynthesized more naringenin α-glucoside (NαG) with sucrose and naringenin as donor and acceptor molecules, respectively, than other ASases from Deinococcus sp. The biotransformation rate of DwAS to NαG was 21.3% compared to 7.1-16.2% for other ASases. Docking simulations showed that the active site of DwAS was more accessible to naringenin than those of others. The 217th valine in DwAS corresponded to the 221st isoleucine in Deinococcus geothermalis AS (DgAS), and the isoleucine possibly prevented naringenin from accessing the active site. The DwAS-V217I mutant had a significantly lower biosynthetic rate of NαG than DwAS. The kcat/Km value of DwAS with naringenin as the donor was significantly higher than that of DgAS and DwAS-V217I. In addition, NαG inhibited human intestinal α-glucosidase more efficiently than naringenin.

Development of occupation-based exposure matrix of lead for Korean workers: challenges and opportunities.

OBJECTIVES: Industry- and occupation-based carcinogen exposure matrices play a pivotal role in preventing occupational cancer. While the Korean CARcinogen EXposure (K-CAREX) has been developed in recent years to assess exposure prevalence and intensity by industry, the feasibility of constructing an occupation-based exposure matrix remains unexplored. Hence, the objective of this study is to explore the potential of combining the nationwide work environment measurement database (WEMD) and the special health examination database (SHED) to develop a comprehensive occupation-based exposure matrix. METHODS: The WEMD provides information on airborne lead measurements, including industry codes, but it does not include data related to occupations. In contrast, the SHED contains information on both occupation and blood lead levels. By integrating these 2 databases, we attempted to assess airborne lead exposure levels by occupation. Additionally, we performed a rank correlation analysis to compare the airborne exposure levels with corresponding blood lead levels according to occupation. RESULTS: A total of 35 425 workers who both wore air samplers for lead and underwent special health examinations for lead were extracted between 2019 and 2021. An occupation-based exposure matrix was developed to evaluate the intensity of lead exposure across a range of occupations, encompassing 51 minor occupations and 70-unit occupations. Rank correlation analyses showed strong positive correlations between airborne lead and blood lead measurements according to occupation. CONCLUSIONS: Our study findings suggest that combining 2 nationwide surveillance databases can be an effective approach for creating an occupation-based exposure matrix. However, our results also highlight several limitations that need to be addressed in future studies to improve the accuracy and reliability of such matrices.

Evaluation on the Sex-Specific Association Between Cigarette Smoke Exposure and Inflammation Markers-C-Reactive Protein and White Blood Cell Count.

INTRODUCTION: Cigarette smoke increases peripheral white blood cell (WBC) count. However, the dose-dependent association between smoking and C-reactive protein (CRP), an important inflammatory marker, has been reported as inconsistent. AIMS AND METHODS: Here, we evaluated the associations between smoking and CRP using both smoking questionnaires and urine cotinine as exposure markers. The Korea National Health and Nutrition Examination Survey data were used for analyzing the associations. Multiple regression analyses were performed to examine the associations between cigarette smoke exposure, as assessed by questionnaires and urine cotinine, and health effects, as measured by CRP and WBC count, controlling for potential confounders. The confounders, including age, sex, body mass index, blood pressure, cholesterol, glucose, alanine aminotransferase, and uric acid, were selected a priori based on the literature. RESULTS: A total of 11 435 participants were included for analysis. For the exposure-response relationship, the results indicated a significant increase in CRP levels in male smokers compared to male nonsmokers (p = .002), whereas no significant increase was found in female smokers compared to female nonsmokers (p = .680). For the dose-response relationship, a significant positive association was observed between urine cotinine and CRP in male smokers (p = .018), whereas no significant association was found in female smokers (p = .508). WBC count consistently showed significant exposure-response and dose-response relationships in both sexes. CONCLUSIONS: WBC count was found to be a consistent effect marker of cigarette smoke exposure, while the association between CRP level and smoking was inconsistent and varied by sex. The sex-specific response to cigarette smoke exposure warrants further exploration in future studies. IMPLICATIONS: Cigarette smoke exposure is known to increase inflammation and has been thought to increase CRP, a significant inflammation marker. However, recent studies have reported conflicting results regarding the dose-dependent association between cigarette smoke exposure and CRP. This study found that the association between smoking and CRP is inconsistent and varies by sex, showing significant exposure response in men but not in women. Furthermore, the study suggests that WBC count is a more consistent marker for cigarette smoke exposure.

Suppression of Pro-Inflammatory M1 Polarization of LPS-Stimulated RAW 264.7 Macrophage Cells by Fucoxanthin-Rich Sargassum hemiphyllum.

Macrophages play an important role in managing the onset and progression of chronic inflammatory diseases. The primary objective of this study is to explore the antioxidant potential and anti-inflammatory properties of Sargassum hemiphyllum ethanol extract (SHE) and its fraction. SHE and its five constituent fractions were assessed for overall antioxidant capabilities and inhibitory effects on LPS-induced inflammation by modulating macrophages polarization in both RAW 264.7 macrophages and bone-marrow-derived macrophages (BMDM). Among the organic solvent fractions of SHE, the ethyl acetate fraction displayed the highest total phenolic content and total antioxidant capacity. Notably, the n-hexane (Hex) fraction showed the most substantial suppression of LPS-induced tumor necrosis factor α secretion in BMDM among the five fractions of SHE. The SHE and Hex fraction significantly reduced the heightened expression of pro-inflammatory cytokines and inflammation-inducible enzymes induced by LPS in RAW 264.7 macrophages. In particular, the SHE and Hex fraction inhibited M1 macrophage polarization by reducing the mRNA expression of M1 macrophage markers in macrophages that were polarized toward the M1 phenotype. Furthermore, the SHE and Hex fraction attenuated the induction in nuclear factor E2-related factor 2 and its target genes, which was accompanied by an alteration in antioxidant gene expression in M1-polarized BMDM. The findings suggest that both SHE and its Hex fraction exhibit inhibitory effects on LPS-triggered inflammation and oxidative stress by modulating the polarization of M1 macrophages within macrophage populations.

Evaluation of Temporal Trends of Lead Exposure in Korean Workers Using Workplace Monitoring Data.

BACKGROUND: Lead, which is widely used in various industrial settings, is a major health hazard for manufacturing workers. Therefore, control of lead exposure has been implemented in an effort to prevent lead-related health problems. In this study, our aim was to evaluate temporal trends in occupational lead exposure in Korean lead workers using data from monitoring of workplace exposure. METHODS: A nationwide work environment monitoring database, data from a work environment monitoring institution, and data extracted from a review paper were utilized. Different versions of standard industrial classification codes were aligned with the 10th Korean Standard Industrial Classification, which is generally consistent with the 4th revision of the International Standard Industrial Classification. The multiple data sources were combined and temporal trends over the period from 1994-2021 were estimated. In addition, separate estimation of temporal trends in the storage battery manufacturing industry over the period from 1987-2021 was also performed. RESULTS: A total of 444,296 personal airborne lead measurements were used for the estimation process. The temporal trends in occupational exposure to lead declined by -6% annually over the study period. In particular, levels of lead exposure in the storage battery manufacturing industry showed a steeper decline of -12% annually. CONCLUSIONS: Findings of our study showed that occupational exposure to lead declined over the period from 1994 to 2021 in Korea. However, adverse effects of exposure to lead on health should be regarded with caution. The results will be useful in conduct of epidemiological studies examining lead-related effects on health.