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Abstract The Nuclear factor erythroid 2–related factor (Nrf2)/ Heme oxygenase-1 (HO-1) pathway, known for its significant role in regulating innate antioxidant defense mechanisms, is increasingly being recognized for its potential in neuroprotection studies. Derived from bee venom, melittin's neuroprotective effects have raised interest. This study confirmed that melittin specificity upregulated the weakened Nrf2/HO-1 signaling in mice brain. Interestingly, we also revealed melittin’s efficient tactic, as it was suggested to first restore redox balance and then gradually stabilized other regulations of the mouse hippocampus. Using a neuro-stress-induced scopolamine model, chromatography and mass spectrometry analysis revealed that melittin crossed the compromised blood–brain barrier and accumulated in the hippocampus, which provided the chance to interact directly to weakened neurons. A wide range of improvements of melittin action were observed from various tests from behavior Morris water maze, Y maze test to immune florescent staining, western blots. As we need to find out what is the focus of melittin action, we conducted a careful observation in mice which showed that: the first signs of changes, in the hippocampus, within 5 h after melittin administration were the restoration of the Nrf2/HO-1 system and suppression of oxidative stress. After this event, from 7 to 12.5 h after administration, a diversity of conditions was all ameliorated: inflammation, apoptosis, neurotrophic factors, cholinergic function, and tissue ATP level. This chain reaction underscores that melittin focus was on redox balance's role, which revived multiple neuronal functions. Evidence of enhancement in the mouse hippocampus led to further exploration with hippocampal cell line HT22 model. Immunofluorescence analysis showed melittin-induced Nrf2 translocation to the nucleus, which would initiating the translation of antioxidant genes like HO-1. Pathway inhibitors pinpointed melittin's direct influence on the Nrf2/HO-1 pathway. 3D docking models and pull-down assays suggested melittin's direct interaction with Keap1, the regulator of the Nrf2/HO-1 pathway. Overall, this study not only highlighted melittin specifically effect on Nrf2/HO-1, thus rebalancing cellular redox, and also showed that this is an effective multi-faceted therapeutic strategy against neurodegeneration.

Background: Invasive laser acupuncture (ILA) involves simultaneous application of focused laser irradiation and acupuncture. This study aims to explore the effects of ILA on knee osteoarthritis (KOA) through a pilot clinical trial. Methods: This prospective, patient-blinded, single-center, and parallel-arm pilot randomized controlled trial will enroll 45 patients with KOA randomized to the control, 830, and 650 groups. All patients will receive education on exercise and self-care. Their ILA treatment will correspond to their group (control group, sham; 830 group, 830 nm; 650 group, 650-nm wavelength laser) for 10 minutes once daily, twice weekly for 6 weeks at EX-LE4, ST35, ST34, SP10, SP9, GB34, and EXLE2 acupoints. Results: The primary endpoint will be changes in the visual analog scale (VAS) score of pain at rest and during activity 1 week after interventions (week 7). The secondary outcomes will be the responder rate; VAS, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total, WOMAC pain subscale, WOMAC function subscale, European quality of life five-dimension five-level scale, and patient global assessment scores; and rescue medication doses. Safety outcome measures will include blood chemistry parameters, occurrence of adverse events, pulse rate, and blood pressure. The efficacy outcomes will be measured at baseline, visit after six treatments, 1 week after the last treatment, and 6 weeks after the last treatment. Conclusion: The findings will provide preliminary data on the effects of ILA on KOA.

We have a limited number of landraces and only a few of them have been used in breeding programs. In the Korean peninsula, maize was introduced before the middle of the 16th century and cultivated widely thereafter. Over 3000 Korean maize landraces have been collected and deposited in the Genebank of the National Agrobiodiversity Center, Korea, which is about a half of total maize germplasm stored in the Genebank. The majority of Korean maize accessions have been maintained as local landraces, implying the preservation of diverse morphological traits with a wide range of variation. However, there has been a few studies for discovering phenotypic characteristics of the Korean maize landraces. We collected phenotype data of 2699 maize germplasm which can be divided by geographic origin (Korean or overseas) and breeding progress (landraces or breeding lines). Principal component analysis demonstrated that the phenotypic variations of the collected maize germplasm were largely explained by flowering time, kernel yields, and stalk diameter traits. From the phenotype data analysis, 276 accessions were selected as a core collection. We also investigated endosperm phenotypes for the core collection and found novel multilayer aleurone germplasms. This indicates that Korean landraces have maintained the original genetic variation which has largely been lost during the modern breeding programs. These findings suggest that the core collection could be a valuable resource for understating and exploiting maize germplasm.

ABSTRACTColorectal cancer (CRC) is the most common malignant tumor and one of the leading causes of cancer-related death worldwide. Oncogene KRAS is a commonly mutated in CRC and plays crucial roles in the colorectal tumorigenesis. Emerging evidence suggests that increased expression levels of c-Myc are critical for KRAS-mediated CRC progression. However, it is unclear exactly how c-Myc expression is regulated in CRC. In the present study, we found that blockade of 5/12-lipoxygenase (5/12-LO) or leukotriene B4 receptor (BLT2) markedly reduced c-Myc expression in KRAS-mutant LOVO cells, while the control COLO 320DM cells were not affected. When the 5/12-LO products LTB4 and 12(S)-HETE, ligands of BLT2, were added to LOVO cells, c-Myc expression levels were restored, together suggesting that ‘5/12-LO-BLT2 cascade’ regulates c-Myc expression in KRAS-mutant CRC cells. We also observed that ‘5/12-LO-BLT2’-mediated c-Myc upregulation contributes to cell proliferation by regulating the expression of cyclin D1 in LOVO cells. Moreover, ‘5/12-LO-BLT2-cMyc’ cascade regulates the expression of EMT-related proteins in KRAS-mutant CRC cells, and depletion of both c-Myc and BLT2 using siRNA significantly enhanced the level of E-cadherin and reduced the level of Vimentin in LOVO cells. Taken together, our findings suggest that the BLT2-linked cascade promotes KRAS-mutant CRC cell proliferation and migration through the elevated expression of c-Myc. Thus, our results suggest that BLT2 appears to be an effective therapeutic target for KRAS-mutant CRCs.

Abstract Ceramic membranes are a promising alternative to polymeric membranes for selective separations, given their ability to operate under harsh chemical conditions. However, current fabrication technologies fail to construct ceramic membranes suitable for selective molecular separations. Herein, we demonstrate a molecular-level design of ceramic thin-film composite membranes with tunable subnanometer pores for precise molecular sieving. Through burning off the distributed carbonaceous species of varied dimensions within hybrid aluminum oxide films, we created membranes with tunable molecular sieving. Specifically, the membranes created with methanol showed exceptional selectivity toward monovalent and divalent salts. We attribute this observed selectivity to the dehydration of the large divalent ions within the subnanometer pores. As a comparison, smaller monovalent ions can rapidly permeate with an intact hydration shell. Lastly, the flux of neutral solutes through each fabricated aluminum oxide membrane was measured for the demonstration of tunable separation capability. Overall, our work provides the scientific basis for the design of ceramic membranes with subnanometer pores for molecular sieving using atomic layer deposition.

Recently, acupuncture has demonstrated extraordinary clinical results in the treatment of several categories of health conditions worldwide. The mechanisms of action of acupuncture (including immune mechanisms) have been investigated by biomedical studies over the last few decades. The immune mechanisms of representative clinical conditions and their clinical effects were thoroughly assessed, with a comprehensive investigation into the mechanisms of action of acupuncture (including immune responses) in this study. Conditions such as stroke, migraine, depression, chronic fatigue syndrome, lower back pain, hypertension, irritable bowel syndrome, sepsis, and allergic diseases were meticulously examined. This in-depth analysis aims to ensure a foundational understanding of the immune mechanisms involved in acupuncture, thereby serving as an initial step toward integrating the impact of acupuncture on the immune system.

Background: The aim of this study is to determine the antioxidant and anti-inflammatory effects of Dusokohwaeum (DOE). Methods: To measure the antioxidant and anti-inflammatory effects of DOE, the total flavonoid and polyphenol contents and radical scavenging activity were measured. Furthermore, reactive oxygen species (ROS), nitric oxide, and cytokine production were measured by treating lipopolysaccharide-induced RAW264.7 cells with DOE, and gene expression levels of inducible cyclooxygenase-2, nitric oxide synthase, and cytokines were evaluated. Results: Radical scavenging experiments revealed a significant concentration-dependent increase in scavenging capacity. The production of ROS, nitric oxide, and cytokines in the cells showed a significant concentration-dependent decrease when compared with the control group. The gene expression levels of inducible cyclooxygenase-2, nitric oxide synthase, and cytokines also showed a significant concentration-dependent decrease when compared with the control group. Conclusion: Interestingly, the antioxidant and anti-inflammatory effects of DOE were 23.42 ± 0.64 mg GAE/g and 20.83 ± 0.98 mg QE/g, respectively. The administration of DOE resulted in a concentration-dependent increase in scavenging ability in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azinobis-(3-ethylbenzothiazoline- 6-sulfonic acid) (ABTS) radical scavenging ability experiments. The production of intracellular ROS and nitric oxide was significantly reduced in the presence of DOE. The production of inflammatory cytokines (prostaglandin E2, tumor necrosis factor-alpha [TNF-α], interleukin-1 beta [IL-1β], and IL-6) was significantly reduced in the presence of DOE. Finally, the expression levels of inducible nitric oxide synthase, cyclooxygenase-2, TNF-α, IL-1β, and IL-6 were significantly decreased in the presence of DOE.

This study aimed to evaluate the clinical efficacy and safety of acupuncture and electroacupuncture for temporomandibular joint disorder (TMD). We searched 11 databases to find randomized-controlled trials (RCTs) published between January 2018 and January 2023 that used acupuncture and electroacupuncture to treat patients with TMD. We performed a meta-analysis of 18 RCTs involving 1,109 patients. Nine studies reported that the treatment and control groups showed improvement in the evaluation index post-treatment. The results of the meta-analysis showed that the treatment groups receiving acupuncture combined with manual therapy had significantly improved visual analog scale score and dysfunction index than the control groups receiving manual therapy. Moreover, the treatment groups receiving acupuncture combined with Western medicine had statistically improved maximum mouth opening than the control groups using Western medicine. In conclusion, acupuncture and electroacupuncture have clinical effects on TMD patients. Given that 11 studies were obtained from the Chinese database, a regional bias would be considered. Furthermore, the included studies had high a risk of bias in terms of randomization, concealment, and blinding. Further studies are required to correct these limitations.

BackgroundMild cognitive impairment (MCI) is an intermediary condition between typical cognitive decline that occurs owing to aging and dementia. It is necessary to implement an intervention to slow the progression from MCI to Alzheimer’s disease. This manuscript reports the protocol for a clinical trial on the effect of acupuncture in patients with MCI.MethodsThe trial will be a randomized, prospective, parallel-arm, active-controlled trial. Sixty-four patients with MCI will be randomized to the Rehacom or acupuncture group (n = 32 each). The participants in the acupuncture group will receive electroacupuncture at GV24 (Shenting) and GV20 (Baihui) and acupuncture at EX-HN1 (Sishencong) once (30 min) a day, twice per week for 12 weeks. The patients in the Rehacom group will receive computerized cognitive rehabilitation using RehaCom software once (30 min) daily, twice weekly for 12 weeks. The primary outcome measure is the change in the Montreal Cognitive Assessment Scale score. The secondary outcome measures are the Geriatric Depression Scale, Alzheimer’s Disease Assessment Scale-Korean version-cognitive subscale-3 scores, and European Quality of Life Five Dimensions Five Level Scale. The safety outcomes will include the incidence of adverse events, blood pressure, blood chemistry parameters, and pulse rate. The efficacy outcome will be assessed at baseline and at six weeks, 13 weeks, and 24 weeks after baseline.DiscussionThe findings of this protocol will provide information regarding the effects of acupuncture on MCI.Clinical trial registrationhttps://cris.nih.go.kr/cris/search/detailSearch.do?search_lang=E&focus=reset_12&search_page=M&pageSize=10&page=undefined&seq=25579&status=5&seq_group=25579, KCT0008861.

Summary: Peptidoglycan recognition protein 1 (PGLYRP1) is a pattern-recognition protein that mediates antibacterial actions and innate immune responses. Its expression and role in neuroinflammatory conditions remain unclear. We observed the upregulation of PGLYRP1 in inflamed human and mouse spinal cord and brain, with microglia being the primary cellular source. Experiments using a recombinant PGLYRP1 protein show that PGLYRP1 potentiates reactive gliosis, neuroinflammation, and consequent behavioral changes in multiple animal models of neuroinflammation. Furthermore, shRNA-mediated knockdown of Pglyrp1 gene expression attenuates this inflammatory response. In addition, we identify triggering receptor expressed on myeloid cell-1 (TREM1) as an interaction partner of PGLYRP1 and demonstrate that PGLYRP1 promotes neuroinflammation through the TREM1-Syk-Erk1/2-Stat3 axis in cultured glial cells. Taken together, our results reveal a role for microglial PGLYRP1 as a neuroinflammation mediator. Finally, we propose that PGLYRP1 is a potential biomarker and therapeutic target in various neuroinflammatory diseases.

BLT2 is a low-affinity leukotriene B4 receptor that plays an essential role in the pathogenesis of various inflammatory diseases, including asthma and cancer. BLT2 is minimally expressed in a normal internal environment but is overexpressed in a stress-induced inflammatory environment. Recent research indicated that human BLT2 has two distinct forms. Although their functions are likely to be different, very few studies investigated these differences. Therefore, this paper will discuss about the two distinct forms of human BLT2; the short-form of BLT2 and the long-form of BLT2.

Much research has shown Bee venom to be an effective neuroprotective agent. However, the usual transdermal injection of bee venom poses many pharmacokinetic disadvantages. Here, we compared the administration of bee venom via subcutaneous injection (SC) and via Microneedle patch (MN). Both administrated routes produce significant recovery effects, however: the MN significantly prolongs the bio-significant-and-yet-lower concentration of bee venom in mice bodies. In contrast, SC could produce only a short period of much higher bee venom levels in the blood and brain. We also see that due to the concentration-response-curve of bee venom (represented by melittin): mice bodies do not require much higher bee venom concentration (seen in the SC group) to produce a much more significant neuroprotective effect (than seen in those treated with the MN method). Therefore, a MN could maintain bee venom levels in mice bodies at lower-yet-more-efficient concentrations. This is important, as bee venom can cause more adverse effects and pain sensations, at higher concentrations. For the first time, we confirmed that the pharmacokinetic advantages of MN delivered bee venom also guarantee a holistic neuroprotection effect (which was shown by SC delivered bee venom in previous research). This was proven via the results of the water maze experiments for long-term learning memory assessment and protein analysis of key neuronal regulatory proteins: BDNF, p-CREB, iNOS, and mArhR 1. In conclusion, for situations where we ought to administrate drugs at a more downward amount, such as bee venom, MN can keep the therapeutic concentrations at a lower, yet interestingly, more-efficient level.

Background and Objectives: The surge in breast-related surgeries in Korea underscores the critical need for an accurate early diagnosis of silicone breast implant-related issues. Complications such as BIA-ALCL and BIA-SCC add complexity to breast health concerns, necessitating vigilant monitoring. Despite advancements, discrepancies persist between ultrasonographic and pathologic classifications of silicone implant ruptures, highlighting a need for enhanced diagnostic tools. This study explores the reliability of ultrasonography in diagnosing silicone breast implant ruptures and determining the extent of silicone migration, specifically with a focus on guiding potential capsulectomy based on pathology. Materials and Methods: A comprehensive review of medical records encompassing 5557 breast implants across 2790 patients who underwent ultrasound-assisted examinations was conducted. Among the screened implants, 8.9% (249 cases) were diagnosed with silicone breast implant rupture through ultrasonography. Subsequently, 89 women underwent revisional surgery, involving capsulectomy. The pathological analysis of 111 periprosthetic capsules from these cases aimed to assess the extent of silicone migration, and the findings were juxtaposed with the existing ultrasonographic rupture classification. Results: The diagnostic agreement between preoperative sonography and postoperative findings reached 100% for silicone breast implant ruptures. All eighty prosthetic capsules exhibiting a snowstorm sign in ultrasonography demonstrated silicone migration to capsules upon pathologic findings. Conclusions: High-resolution ultrasonography emerged as a valuable and reliable imaging modality for diagnosing silicone breast implant ruptures, with a notable ability to ascertain the extent of free silicone migration to capsules. This diagnostic precision is pivotal in informing decisions about potential capsulectomy during revisional surgery. The study advocates for an update to the current binary ultrasonographic classification, suggesting a more nuanced categorization into three types (subcapsular, intracapsular, and extracapsular) based on pathology.

Subnanometer-confined reaction is the frontier of catalytic chemistry, yet it is challenging to form the angstrom channels with distributed atomic catalytic centers within, and to match the internal mass transfer and the reactive species’ lifetimes. Here, the authors resolve these issues by applying the concept of the angstrom-confined catalytic water contaminant degradation.

Abstract Background Classical porcine parvovirus (PPV1) and novel porcine parvoviruses designated porcine parvovirus 2 through 7 (PPV2-PPV7) are widespread in pig populations. The objective of this study was to investigate the prevalence rates of PPV1-PPV7 in Korea by detecting PPVs in serum, lung and fecal samples and to elucidate the association of PPVs with porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory virus (PRRSV), major pathogens involved in porcine respiratory disease complex (PRDC). A total of 286 serum, 481 lung, and 281 fecal samples collected from 2018 to 2020 were analyzed. Results The results showed that PPVs are widespread in Korea; the highest detection rates were found in lung samples and ranged from 7.9% (PPV1) to 32.6% (PPV2). Regarding age groups, fattening pigs had the highest detection rates of PPVs, ranging from 6.4% (PPV1) to 36.5% (PPV6); this finding suggests the chronic nature of PPV infections and the continual circulation of these viruses. When compared with PCV2- and PRRSV-negative lung samples, PCV2-positive samples with or without PRRSV positivity had significantly higher detection levels of PPV1 and PPV6. In contrast, the prevalence of PPV2 and PPV7 was significantly higher in PRRSV-infected lung samples regardless of PCV2 detection. PPV5 was detected significantly more frequently in samples with both PCV2 and PRRSV positivity. Conclusions This study could offer a better understanding of the role of PPVs in PCV2 and/or PRRSV infection though further studies are needed to experimentally assess the impact of PPVs in coinfections.

BackgroundWe aim to obtain clinical trial data regarding the safety, efficacy, and usefulness of invasive laser acupuncture (ILA) for non-specific chronic low back pain (NSCLBP) through a randomized placebo-controlled trial.MethodsOur clinical trial will be an assessor- and patient-blinded, prospective, parallel-arm, multi-center, randomized placebo-controlled clinical trial. One hundred and six participants with NSCLBP will be allocated evenly to the 650 ILA or control group. All participants will receive education on exercise and self-management. The 650 ILA group will undergo 650 nm ILA for 10 min, and the control group will undergo sham ILA for 10 min per visit, twice a week for 4 weeks, at bilateral GB30, BL23, BL24, and BL25. The primary outcome will be the proportion of responders (≥30% reduction in pain visual analogue scale [VAS] without increased use of painkillers) at 3 days after the intervention ends. The secondary outcomes will include changes in the scores of the VAS, European Quality of Life Five Dimension Five Level scale, and Korean version of the Oswestry Disability Index at 3 days after the intervention ends and 8 weeks after the intervention ends.DiscussionsThe results of our study will provide clinical evidence concerning the safety and efficacy of 650 nm ILA for the management of NSCLBP.Clinical trial registrationhttps://cris.nih.go.kr/cris/search/detailSearch.do?search_lang=E&focus=reset_12&search_page=M&pageSize=10&page=undefined&seq=21591&status=5&seq_group=21591, identifier KCT0007167.

Background and Objectives: With the emergence of breast implant-associated anaplastic large cell lymphoma (BIA-ALCL), it has become necessary to identify the implant shell type patients have received. Therefore, an immediate, reliable method for identifying a breast implant shell type is essential. Evidence-based research and applying a real-world technique that identifies the surface topographic information of the inserted breast implants, without surgery, has become of paramount importance for breast implant physicians. Methods and Materials: A review of the medical records of 1901 patients who received 3802 breast implants and subsequently received an ultrasound-assisted examination was performed. All patients received not only a breast cancer examination but also a high-resolution ultrasonography (HRUS) assisted examination of the device at a single center between 31 August 2017 and 31 December 2022. Results: Most patients had breast implants within 10 years (77.7%) of the examination. Of the 3802 implants screened, 2034 (53.5%) were identified with macro-textured shell topography in ultrasonography. A macrotextured shell type implant was used in 53.5% of cases and a smooth type in 42.7% of cases. Seventy-three (1.9%) breast implant shell types could not be identified due to ruptures. However, 250 breast implant shell types could be identified despite rupture cases (6.5%). Conclusions: HRUS was found to be a useful and reliable image modality for identifying various surface shell types of breast implants. The shell type information would be helpful to patients who lack information about their breast implants and are concerned about BIA-ALCL.

Transgenic mice are a useful tool for exploring various aspects of gene function. A key element of this approach is the targeted overexpression of specific genes in cells or tissues. Herein, we report for the first time, the generation and characterization of conditional transgenic (cTg) mice for lipocalin-2 (LCN2) expression. We generated the R26-LCN2-transgenic (LCN2-cTg) mice that carried a loxP-flanked STOP (neo) cassette, Lcn2 cDNA, and a GFP sequence. When bred with Tg mice expressing Cre recombinase under the control of various tissues or cell-specific promoters, Cre-mediated recombination deletes the STOP cassette and allows the expression of LCN2 and GFP. In this study, we achieved the recombination of loxP-flanked LCN2 in hippocampal astrocytes of cTg mouse brain, using a targeted delivery of adeno-associated virus (AAVs) bearing Cre recombinase under the control of a GFAP promoter (AAVs-GFAP-mCherry-Cre). These mice with localized LCN2 overexpression in astrocytes of the hippocampus developed neuroinflammation with enhanced glial activation and increased mRNA and protein levels of proinflammatory cytokines. Furthermore, mice showed impairment in cognitive functions as a typical symptom of hippocampal inflammation. Taken together, our study demonstrates the usefulness of LCN2-cTg mice in targeting specific cells at various organs for conditional LCN2 expression and for subsequent investigation of the functional role of cell-type-specific LCN2 within these sites. Moreover, the LCN2-cTg mice with targeted expression of LCN2 in hippocampal astrocytes are a new in vivo model of neuroinflammation.

This study aimed to provide preliminary evidence for the efficacy of invasive laser acupuncture (ILA) for chronic non-specific low back pain (CNLBP). This was a single-center, randomized, patient and assessor-blinded, placebo-controlled, parallel-arm, clinical trial with a 1:1:1 allocation ratio that included a full analysis set. Forty-five participants with CNLBP were randomly assigned to the control group (sham laser), 650 group (650 nm-wavelength ILA), or 830 group (830 nm-wavelength ILA) (n = 15/group). All participants received ILA for 10 min, followed by electroacupuncture for 10 min on the same day. The treatment was performed once per day, twice per week for 4 weeks at bilateral BL23, BL24, BL25, and GB30. The primary outcome was the among-group difference of changes in the visual analog scale (VAS) scores at intervention endpoint (week 4). The secondary outcomes were the among-group difference of changes in VAS at 4 weeks after intervention completion (week 8), those in the Korean version of the Oswestry Disability Index (ODI) and the European Quality of Life Five-Dimension- Five-Level (EQ-5D-5L) at intervention endpoint (week 4) and 4 weeks after intervention completion (week 8). The VAS scores of the 650 group decreased significantly compared with those of the control group (p = 0.047; week 4 vs. week 0). The ODI scores of the 650 group (p = 0.018, week 4 vs. week 0; p = 0.006, week 8 vs. week 0) and 830 group (p = 0.014, week 4 vs. week 0) decreased significantly compared with those of the control group. There was no adverse event related to ILA and no significant difference in changes in vital signs among the three groups. The 650 group showed significant improvements in pain intensity and functional disability. The 830 group showed significant improvements in functional disability. Therefore, ILA therapy at 650 nm and 830 nm wavelengths can be used to treat CNLBP.

Chimeric lysins composed of various combinations of cell wall-lysing (enzymatic) and cell-wall-binding (CWB) domains of endolysins, autolysins, and bacteriocins have been developed as alternatives to or adjuvants of conventional antibiotics. The screening of multiple chimeric lysin candidates for activity via E. coli expression is not cost effective, and we previously reported on a simple cell-free expression system as an alternative. In this study, we sufficiently improved upon this cell-free expression system for use in screening activity via a turbidity reduction test, which is more appropriate than a colony reduction test when applied in multiple screening. Using the improved protocol, we screened and compared the antibacterial activity of chimeric lysin candidates and verified the relatively strong activity associated with the CHAP (cysteine, histidine-dependent amidohydrolase/peptidase) domain of secretory antigen SsaA-like protein (ALS2). ALS2 expressed in E. coli showed two major bands, and the smaller one (subprotein) was shown to be expressed by an innate downstream promoter and start codon (ATG). The introduction of synonymous mutations in the promoter resulted in clearly reduced expression of the subprotein, whereas missense mutations in the start codon abolished antibacterial activity as well as subprotein production. Interestingly, most of the S. aureus strains responsible for bovine mastitis were susceptible to ALS2, but those from human and chicken were less susceptible. Thus, the simple and rapid screening method can be applied to select functional chimeric lysins and define mutations affecting antibacterial activity, and ALS2 may be useful in itself and as a lead molecule to control bovine mastitis.

Abstract Engineered G protein‐coupled receptors (GPCRs) are commonly used in chemogenetics as designer receptors exclusively activated by designer drugs (DREADDs). Although several GPCRs have been studied in astrocytes using a chemogenetic approach, the functional role of the astrocytic Gi pathway is not clear, as the literature is conflicting depending on the brain regions or behaviors investigated. In this study, we evaluated the role of the astrocytic Gi pathway in neuroinflammation using a Gi‐coupled DREADD (hM4Di). Gi‐DREADD was expressed in hippocampal astrocytes of a lipopolysaccharide (LPS)‐induced neuroinflammation mouse model using adeno‐associated viruses. We found that astrocyte Gi‐DREADD stimulation using clozapine N‐oxide (CNO) inhibits neuroinflammation, as characterized by decreased levels of proinflammatory cytokines, glial activation, and cognitive impairment in mice. Subsequent experiments using primary astrocyte cultures revealed that Gi‐DREADD stimulation significantly downregulated LPS‐induced expression of Nos2 mRNA and nitric oxide production. Similarly, in vitro calcium imaging showed that activation of the astrocytic Gi pathway attenuated intracellular calcium transients triggered by LPS treatment, suggesting a positive correlation between enhanced calcium transients and the inflammatory phenotype of astrocytes observed in the inflamed brain. Taken together, our results indicate that the astrocytic Gi pathway plays an inhibitory role in neuroinflammation, providing an opportunity to identify potential cellular and molecular targets to control neuroinflammation.

Granulocyte colony-stimulating factor (G-CSF) has been suggested to be closely associated with neutrophilic asthma pathogenesis. However, little is known about the factors regulating the production of G-CSF in neutrophilic asthma. We previously reported that a leukotriene B4 receptor 2, BLT2, played an important role in neutrophilic airway inflammation. Therefore, in the current study, we investigated whether BLT2 plays a role in the production of G-CSF in lipopolysaccharide/ovalbumin (LPS/OVA)-induced steroid-resistant neutrophilic asthma. The data showed that BLT2 critically mediated G-CSF production, contributing to the progression of neutrophilic airway inflammation. We also observed that 12-lipoxygenase (12-LO), which catalyzes the synthesis of the BLT2 ligand 12(S)-HETE, was also necessary for G-CSF production. Together, these results suggest that the 12-LO-BLT2-linked signaling network is critical for the production of G-CSF, contributing to the development of neutrophilic airway inflammation. Our findings can provide a potential new target for the therapy of severe neutrophilic asthma.

Accumulated clinical and biomedical evidence indicates that the gut microbiota and their metabolites affect brain function and behavior in various central nervous system disorders. This study was performed to investigate the changes in brain metabolites and composition of the fecal microbial community following injection of amyloid β (Aβ) and donepezil treatment of Aβ-injected mice using metataxonomics and metabolomics. Aβ treatment caused cognitive dysfunction, while donepezil resulted in the successful recovery of memory impairment. The Aβ + donepezil group showed a significantly higher relative abundance of Verrucomicrobia than the Aβ group. The relative abundance of 12 taxa, including Blautia and Akkermansia, differed significantly between the groups. The Aβ + donepezil group had higher levels of oxalate, glycerol, xylose, and palmitoleate in feces and oxalate, pyroglutamic acid, hypoxanthine, and inosine in brain tissues than the Aβ group. The levels of pyroglutamic acid, glutamic acid, and phenylalanine showed similar changes in vivo and in vitro using HT-22 cells. The major metabolic pathways in the brain tissues and gut microbiota affected by Aβ or donepezil treatment of Aβ-injected mice were related to amino acid pathways and sugar metabolism, respectively. These findings suggest that alterations in the gut microbiota might influence the induction and amelioration of Aβ-induced cognitive dysfunction via the gut–brain axis. This study could provide basic data on the effects of Aβ and donepezil on gut microbiota and metabolites in an Aβ-induced cognitive impairment mouse model.