Construction of mouse intestinal organoid inflammation model / 天津医药

Objective To establish in vitro the small intestinal organoid culture system and to investigate the effect of lipopolysaccharide(LPS)on the growth of small intestinal organoids and the secretion of inflammatory factors.Methods In vitro,the small intestinal crypt cell mass of C57BL/6 mice was aseptically isolated,collected and embedded in organoid matrix.Under the support of complete medium,the small intestinal organoids with three-dimensional multi-leaf structure with small intestinal epithelioid structure were formed.The small intestinal organoids were subcultured after 5-7 d culture.On the third day after passage,the small intestinal organoids were randomly divided into different mass concentrations of LPS groups(0,150,175,200,225,250,275 and 300 mg/L).After 24 h and 48 h of LPS induction,morphological changes of small intestinal organoid growth and differentiation were observed.CCK-8 method was used to detect the effect of different time points and mass concentrations of LPS on the proliferative activity of small intestinal organoids after induction of inflammation.The effects of four different mass concentrations of LPS(0,175,200 and 225 mg/L)on expression levels of granulocyte-macrophage colony stimulating factor(GM-CSF),interleukin(IL)-1α,IL-6 and IL-10 in organoid culture supernatant at different times were detected by enzyme-linked immunosorbent assay(ELISA).Results The mouse small intestinal organoid culture system was preliminarily constructed.After different time and mass concentration of LPS induced inflammation of small intestinal organoids,it was observed by morphology that small intestinal organoids would have different degrees of expansion and apoptosis in lumen.The proliferation,differentiation and budding of damaged intestinal epithelial crypts or intestinal stem cells were also inhibited to varying degrees,indicating that the growth of small intestinal organoids would be limited to varying degrees after induced inflammation.The proliferation activity of small intestinal organoids decreased to varying degrees after 24 h and 48 h of LPS induction at 175-225 mg/L(P＜0.05),but the cell viability was still greater than 50%.The levels of IL-1α,IL-6 and GM-CSF partially increased after induction with 200 mg/L and 225 mg/L LPS for 24 h and 48 h(P＜0.05).The level of IL-10 decreased after induction with 200 mg/L LPS for 24 h and 48 h(P＜0.05).Conclusion In this study,a model of intestinal inflammatory injury in vitro induced by LPS with different mass concentrations and time points is preliminarily constructed,which provides a more reliable research platform for the mechanism research of intestinal diseases and the screening of effective drugs in the future.

Effect of exosomes and the preconditioning method on pulp regeneration / 中国组织工程研究

BACKGROUND:Existing studies have confirmed that exosomes can effectively promote pulp regeneration.However,the biological functions and properties of exosomes from preconditioned sources can be significantly changed,which have different effects on cell proliferation,migration and odontogenic differentiation. OBJECTIVE:To discuss the application status of exosomes and their preconditioning methods in the field of pulp regeneration,and summarize the preconditioning methods that affect the function of exosomes,and explore the effect of exosomes and their preconditioning on pulp regeneration. METHODS:The relevant articles were searched in WanFang,CNKI,PubMed,and Web of Science databases from 2006 to 2022.The Chinese and English search terms were"exosomes,pulp regeneration;preconditioning method".A total of 78 articles were included for analysis. RESULTS AND CONCLUSION:(1)Exosomes have the advantages of good biocompatibility,low immunogenicity and no cytotoxicity,and can induce the regeneration of pulp tissue by promoting stem cell tooth formation,neurogenesis and vascularization.(2)Exosomes derived from preconditioning can enhance the ability of tissue repair and regeneration and have a significant impact on the quality of regenerated dental pulp.(3)Currently,the preconditioning methods used in the field of dental pulp regeneration include inflammatory stimulation,hypoxia induction,conditioned medium and three-dimensional culture,and secreted exosomes can effectively improve the quality of regenerated dental pulp.Nevertheless,the specific effect and mechanism of different preconditioning methods on pulp regeneration need to be explored.

Improved effect and underlying mechanism of methylene blue on cognitive function in brain-inflammatory-aging rats / 中华老年心脑血管病杂志

Objective To determine the improved effect of methylene blue(MB)on cognitive func-tion in brain-inflammatory-aging rats and investigate the underlying mechanism.Methods A total of 38 healthy 12-month-old SD rats were randomly divided into healthy control group,lipopo-lysaccharide(LPS)group,MB vehicle group and MB group,with 8 rats in the control and 10 rats in the other three groups.LPS was injected into the fourth ventricle with aid of a subcutaneous sustained release pump to establish a rat model of brain chronic inflammatory aging.MB of 0.5 mg/(kg·d)was added into the pump in the rats from the MB group.T-maze test and new object recognition test were employed to evaluate the learning and memory abilities of the rats.The acti-vation of microglia and astrocytes in the hippocampal CA1 region of the rats was detected by im-munofluorescence assay.The release of inflammatory factors IL-1β and IL-6 was measured by ELISA,and neuronal death in the CA1 region was assessed by neuronal nuclei(NeuN)fluores-cence staining.Results There was no significant difference in the exploration time for new and old objects between the LPS group and the MB solvent group(P＞0.05).The MB group spent significantly longer time in exploring the new objects than the old object(22.50±4.32 s vs 11.60± 3.01 s,P=0.000).The alternating selection rate of new arm and expression level of NeuN antigen were significantly decreased,and the expression levels of ionized calcium binding adaptor mole-cule-1(Iba-1)and glial fibrillary acidic protein(GFAP)and the contents of IL-1β and IL-6 were obviously increased(P＜0.05)in the LPS group and the MB vehicle group than the healthy con-trol group.Compared with the MB vehicle group,the MB group had notably increased alternating selection rate of new arms and higher NeuN expression level,and decreased Iba-1 and GFAP ex-pression and IL-1β and IL-6 contents(P＜0.05).Conclusion Subcutaneous administration of MB could significantly inhibit the damages of spatial learning and memory abilities in the LPS-induced brain chronic inflammatory aging rats.The mechanism may be closely associated with MB inhibi-ting inflammatory glial cells and protecting hippocampal pyramidal neurons.

Effect of Lactobacillus-derived outer vesicles on lipopolysaccharide-induced activation of microglia and proteomic analysis / 中华麻醉学杂志

Objective:To evaluate the effect of Lactobacillus-derived extracellular vesicles (Lac-EVs) on lipopolysaccharide (LPS)-induced activation of microglia and proteomic analysis.Methods:BV2 microglia obtained from mice with good growth status were divided into 3 groups ( n=12 each) using a random number table method: control group (group C), LPS group (group L) and LPS+ Lac-EVs group (group L+ E). Group C was commonly cultured. Group L was incubated for 24 h with LPS (final concentration 1 μg/ml). Group L+ E was incubated for 24 h with Lac-EVs (final concentration 2.5 μg/ml) after being treated with LPS for 24 h. The expression of CD86 and CD206 was detected using immunofluorescence staining. Cell precipitates were taken from L and L+ E groups, and proteomics were used to screen for differentially expressed proteins between the two groups. The differentially expressed proteins were analyzed by the bioinformatics analysis, and two differentially expressed proteins, apolipoprotein A1 and G protein-coupled receptor kinase 2, were verified by quantitative real-time polymerase chain reaction and Western blot. Results:Compared with group C, the expression of CD86 was significantly up-regulated, and the expression of CD206 was down-regulated in group L ( P<0.05). Compared with group L, the expression of CD86 was significantly down-regulated, and the expression of CD206 was up-regulated in L+ E group ( P<0.05). One hundred and twenty-five differentially expressed proteins were identified using proteomics (FC=2.0, P<0.05), of which the expression of 66 proteins was up-regulated and the expression of 59 proteins was down-regulated. The results of GO analysis indicated that these differentially expressed proteins were mainly involved in biological processes such as endothelial cell proliferation, SDNA damage detection, and lipoprotein transport. The results of KEGG analysis indicated that there were differences in PPAR signaling pathway, endocytosis, metabolic pathway, MAPK signaling pathway, etc. The expression trends of the differentially expressed proteins determined by Western blot and quantitative real-time polymerase chain reaction were consistent with the results of proteomics. Conclusions:Lac-EVs can inhibit LPS-induced microglial polarization toward M1 phenotype, and the mechanism may be related to the up-regulated differential proteins apolipoprotein A1 and G protein-coupled receptor kinase 2.

Role of RhoA in hydrogen-induced alleviation of lipopolysaccharide-caused damage to pulmonary microvascular endothelial cell barrier function in mice / 中华麻醉学杂志

Objective:To evaluate the role of Ras homolog gene family member A (RhoA) in hydrogen-induced alleviation of lipopolysaccharide (LPS)-caused damage to pulmonary microvascular endothelial cell(PMVEC) barrier function in mice.Methods:PMVECs were cultured in DMEM/F12 medium containing 10% fetal bovine serum and 1% penicillin/streptomycin until 4-6 passage. These cells were divided into 6 groups ( n=36 each) using a random number table method: control group (group A), hydrogen-rich medium group (group B), LPS group (group C), LPS + hydrogen-rich medium group (group D), LPS + RhoA inhibitor C3 enzyme group (group E) and LPS + hydrogen-rich medium + RhoA agonist U-46619 group (group F). Cells were cultured within normal medium in group A, group C and group E and within hydrogen-rich medium in group B, group D and group F. LPS at a final concentration of 1 μg/ml was simultaneously added in group C, group D, group E and group F. C3 enzyme at a final concentration of 3 μg/ml was added at 2 h before addition of LPS in group E. U-46619 at a final concentration of 10 mg/ml was added at 3 h before addition of LPS in group F. The expression of vascular endothelial (VE)-cadherin and occludin was determined by Western blot at 6, 12 and 24 h after incubation with LPS. At 24 h after incubation with LPS, the release rate of LDH was measured by LDH method, cell viability was measured by MTT method, and the activity of RhoA was determined by GST pull-down method. Results:Compared with group A, the expression of VE-cadherin and occludin was significantly down-regulated at 6, 12 and 24 h of incubation, the cell viability was decreased at 24 h of incubation, and the release rate of LDH and activity of RhoA were increased in group C ( P<0.05). Compared with group C, the expression of VE-cadherin and occludin was significantly up-regulated at 6, 12 and 24 h of incubation, the cell viability was increased at 24 h of incubation, and the release rate of LDH and activity of RhoA were decreased in group D ( P<0.05). Compared with group C, the expression of VE-cadherin and occludin was significantly up-regulated at 6, 12 and 24 h of incubation, the cell viability was increased at 24 h of incubation, and the release rate of LDH and activity of RhoA were decreased in group E ( P<0.05). Compared with group D, the expression of VE-cadherin and occludin was significantly down-regulated at 6, 12 and 24 h of incubation, the cell viability was decreased at 24 h of incubation, and the release rate of LDH and activity of RhoA were increased in group F ( P<0.05). Conclusions:RhoA is involved in hydrogen-induced alleviation of LPS-caused damage to PMVEC barrier function in mice.

Blumea balsamifera （L.） DC Oil Alleviates LPS-Induced Inflammatory Response in Macrophages by Affecting Arachidonic Acid Metabolism Via NF-κB Nonclassical Pathway / 中山大学学报(医学科学版)

ObjectiveTo study the anti-inflammatory effects of Blumea balsamifera （L.） DC oil （BBO） based on nuclear factor kappa-B （NF-κB） nonclassical and arachidonic acid （AA） pathway. MethodsEffects of BBO on the production of slow reacting substance of anaphylaxis （SRS-A） were detected by the ileal smooth muscle method. The contents of prostaglandin E2 （PGE2） and leukotriene B4 （LTB4） in lipopolysaccharides （LPS） -induced macrophages were detected by ELISA kit. The expression of COX-2， 5-LOX， FLAP and RelB were detected by qRT-PCR. Western blot was performed to detect the effects of BBO on the level of NF-κB nonclassical pathway proteins TNF receptor associated factor 3 （TRAF3）， TNF receptor associated factor 2 （TRAF2）， NF-κB-inducing kinase （NIK）， p100 and RelB. ResultsThe contractile tension of guinea pig ileum was reduced （P<0.001）， and the SRS-A production inhibition rate reached 65.34% at 1mg·mL-1 BBO concentration. Compared with LPS group， BBO reduced the concentrations of PGE2 （P<0.05） and LTB4 （P<0.05）， and decreased the expressions of COX-2 （P<0.05）， 5-LOX （P<0.05） and FLAP （P<0.05） in AA pathway at concentrations of 40-80 μg·mL-1. Moreover， 40-80 μg·mL-1 BBO decreased the concentrations of TRAF3 （P<0.05）， TRAF2 （P<0.05）， and NIK （P<0.05）， and further inhibited the phosphorylation of p100 （P<0.05）， as well as the level of the transcription factor RelB in genes （P<0.05） and proteins （P<0.05） in nonclassical NF-κB pathway， whereas BBO did not cause such changes. ConclusionBBO may potentially exert its anti-inflammatory effects by suppressing the regulatory proteins TRAF3 and TRAF2 and the transcription factor RelB in NF-κB nonclassical pathway. The inhibitory action extending to the induction kinase function of NIK， further hindering the phosphorylation of p100 and its binding with the transcription factor RelB. Consequently， downstream elements in the AA pathway， including the pivotal rate-limiting enzymes COX-2， 5-LOX and FLAP， were altered. This modulation influences the levels of inflammatory mediators such as PGE2 and LTB4.

Inhibition of lipopolysaccharide-induced NF-κB maintains osteogenesis of dental pulp and periodontal ligament stem cells

Abstract Dental pulp stem cells (DPSCs) and periodontal ligament stem cells (PDLSCs) can differentiate into osteoblasts, indicating that both are potential candidates for bone tissue engineering. Osteogenesis is influenced by many environmental factors, one of which is lipopolysaccharide (LPS). LPS-induced NF-κB activity affects the osteogenic potencies of different types of MSCs differently. This study evaluated the effect of LPS-induced NF-κB activity and its inhibition in DPSCs and PDLSCs. DPSCs and PDLSCs were cultured in an osteogenic medium, pretreated with/without NF-κB inhibitor Bay 11-7082, and treated with/without LPS. Alizarin red staining was performed to assess bone nodule formation, which was observed under an inverted light microscope. NF-κB and alkaline phosphatase (ALP) activities were measured to examine the effect of Bay 11-7082 pretreatment and LPS supplementation on osteogenic differentiation of DPSCs and PDLSCs. LPS significantly induced NF-κB activity (p = 0.000) and reduced ALP activity (p = 0.000), which inhibited bone nodule formation in DPSCs and PDLSCs. Bay 11-7082 inhibited LPS-induced NF-κB activity, and partially maintained ALP activity and osteogenic potency of LPS-supplemented DPSCs and PDLSCs. Thus, inhibition of LPS-induced NF-κB activity can maintain the osteogenic potency of DPSCs and PDLSCs.

Intravital Microscopy Evidence That Methylene Blue Should Be a Vasopressor-Sparing Agent in Sepsis Vasoplegia

ABSTRACT Microvasculature failure is expected in sepsis and at higher amine concentrations. Therefore, special attention focused individually on microcirculation is needed. Here, we present that methylene blue can prevent leukocytes from adhering to the endothelium in a rat model of lipopolysaccharide-induced endotoxemia. As hypothesis evidence, an intravital microscopy image is presented.

Effects of atelectatic areas on the surrounding lung tissue during mechanical ventilation in an experimental model of acute lung injury induced by lipopolysaccharide / Efeitos das áreas atelectásicas no tecido pulmonar circundante durante a ventilação mecânica em um modelo experimental de lesão pulmonar aguda induzida por lipopolissacarídeo

ABSTRACT Objective: To assess the effect of atelectasis during mechanical ventilation on the periatelectatic and normal lung regions in a model of atelectasis in rats with acute lung injury induced by lipopolysaccharide. Methods: Twenty-four rats were randomized into the following four groups, each with 6 animals: the Saline-Control Group, Lipopolysaccharide Control Group, Saline-Atelectasis Group, and Lipopolysaccharide Atelectasis Group. Acute lung injury was induced by intraperitoneal injection of lipopolysaccharide. After 24 hours, atelectasis was induced by bronchial blocking. The animals underwent mechanical ventilation for two hours with protective parameters, and respiratory mechanics were monitored during this period. Thereafter, histologic analyses of two regions of interest, periatelectatic areas and the normally-aerated lung contralateral to the atelectatic areas, were performed. Results: The lung injury score was significantly higher in the Lipopolysaccharide Control Group (0.41 ± 0.13) than in the Saline Control Group (0.15 ± 0.51), p < 0.05. Periatelectatic regions showed higher lung injury scores than normally-aerated regions in both the Saline-Atelectasis (0.44 ± 0.06 x 0.27 ± 0.74 p < 0.05) and Lipopolysaccharide Atelectasis (0.56 ± 0.09 x 0.35 ± 0.04 p < 0.05) Groups. The lung injury score in the periatelectatic regions was higher in the Lipopolysaccharide Atelectasis Group (0.56 ± 0.09) than in the periatelectatic region of the Saline-Atelectasis Group (0.44 ± 0.06), p < 0.05. Conclusion: Atelectasis may cause injury to the surrounding tissue after a period of mechanical ventilation with protective parameters. Its effect was more significant in previously injured lungs.

RESUMO Objetivo: Avaliar o efeito da atelectasia durante a ventilação mecânica nas regiões periatelectáticas e pulmonares normais em um modelo de atelectasia em ratos com lesão pulmonar aguda induzida por lipopolissacarídeo. Métodos: Foram distribuídos aleatoriamente 24 ratos em quatro grupos, cada um com 6 animais: Grupo Salina-Controle, Grupo Lipopolissacarídeo-Controle, Grupo Salina-Atelectasia e Grupo Lipopolissacarídeo-Atelectasia. A lesão pulmonar aguda foi induzida por injeção intraperitoneal de lipopolissacarídeo. Após 24 horas, a atelectasia foi induzida por bloqueio brônquico. Os animais foram submetidos à ventilação mecânica por 2 horas com parâmetros ventilatórios protetores, e a mecânica respiratória foi monitorada durante esse período. Em seguida, foram realizadas análises histológicas de duas regiões de interesse: as áreas periatelectásicas e o pulmão normalmente aerado contralateral às áreas atelectásicas. Resultados: O escore de lesão pulmonar foi significativamente maior no Grupo Controle-Lipopolissacarídeo (0,41 ± 0,13) do que no Grupo Controle-Solução Salina (0,15 ± 0,51), com p < 0,05. As regiões periatelectásicas apresentaram escores maiores de lesão pulmonar do que as regiões normalmente aeradas nos Grupos Atelectasia-Solução Salina (0,44 ± 0,06 versus 0,27 ± 0,74, p < 0,05) e Atelectasia-Lipopolissacarídeo (0,56 ± 0,09 versus 0,35 ± 0,04, p < 0,05). O escore de lesão pulmonar nas regiões periatelectásicas foi maior no Grupo Atelectasia-Lipopolissacarídeo (0,56 ± 0,09) do que na região periatelectásica do Grupo Atelectasia-Solução Salina (0,44 ± 0,06), p < 0,05. Conclusão: A atelectasia pode causar lesão no tecido circundante após um período de ventilação mecânica com parâmetros ventilatórios protetores. Seu efeito foi mais significativo em pulmões previamente lesionados.

Role of lipopolysaccharide in the development and progression of liver cancer / 临床肝胆病杂志

Liver cancer is an important public health issue worldwide. With the improvements in high-throughput sequencing and gene editing techniques in recent years, studies have further revealed the biological mechanism of intestinal microflora in the development, progression, and metastasis of liver cancer via the gut-liver axis, and in particular, it has been found that lipopolysaccharide, a component of the outer membrane of gram-negative bacteria, can cause downstream immune cascade reactions. This article reviews the possible mechanism of action of intestinal microflora lipopolysaccharide in the development and progression of liver cancer from the aspects of the association between intestinal environmental changes and liver cancer, immunoregulation by lipopolysaccharide, and preclinical treatment.

Correlation of probiotic consumption with serum inflammatory cytokines, endotoxin and post-stroke depression severity in patients with ischemic stroke / 国际脑血管病杂志

Objective:To investigate the correlation of probiotic consumption level with serum inflammatory cytokines, endotoxin and post-stroke depression (PSD) severity in patients with ischemic stroke.Methods:Patients with ischemic stroke visited the Department of Neurology, the Third Affiliated Hospital of Naval Medical University from May 2021 to June 2022 were prospectively included. At 6 months after discharge, the outpatient follow-up was conducted to investigate the consumption of probiotic products in the past six months, and depression was evaluated using the Self-rating Depression Scale (SDS). Multiple linear regression analysis was used to determine the correlation of consumption levels of probiotic products and serum inflammatory cytokines, endotoxin, and PSD severity.Results:A total of 168 patients with ischemic stroke were included, including 74 patients (44.0%) in the probiotic product high consumption group and 94 (56.0%) in the low consumption group. The incidence of PSD in the high consumption group was significantly lower than that in the low consumption group (22.97% vs. 38.30%; χ2=6.551, P=0.036). The serum pro-inflammatory cytokine interleukin-6 (IL-6) and endotoxin levels at the follow-up in the high consumption group were significantly lower than those in the low consumption group, while the anti-inflammatory cytokine IL-10 was significantly higher than that in the low consumption group (all P<0.05). Multiple linear regression analysis shows that the probiotic consumption level was significantly negatively correlated with the serum IL-6 ( β=-0.178, P=0.001) and endotoxin ( β=-0.107, P=0.035) at follow-up. PSD severity (SDS score) was negatively correlated with probiotic consumption level ( β=-0.309, P=0.001), and was positively correlated with IL-6 ( β=0.306, P=0.027) and endotoxin ( β=0.360, P=0.017) at follow-up. Conclusion:Probiotic products can reduce the severity of serum pro-inflammatory cytokines, endotoxin and PSD, and may be a non-drug treatment direction for PSD.

Chronic exposure to lipopolysaccharides as an in vitro model to simulate the impaired odontogenic potential of dental pulp cells under pulpitis conditions

Abstract Simulating a bacterial-induced pulpitis environment in vitro may contribute to exploring mechanisms and bioactive molecules to counteract these adverse effects. Objective To investigate the chronic exposure of human dental pulp cells (HDPCs) to lipopolysaccharides (LPS) aiming to establish a cell culture protocol to simulate the impaired odontogenic potential under pulpitis conditions. Methodology HDPCs were isolated from four healthy molars of different donors and seeded in culture plates in a growth medium. After 24 h, the medium was changed to an odontogenic differentiation medium (DM) supplemented or not with E. coli LPS (0 - control, 0.1, 1, or 10 µg/mL) (n=8). The medium was renewed every two days for up to seven days, then replaced with LPS-free DM for up to 21 days. The activation of NF-κB and F-actin expression were assessed (immunofluorescence) after one and seven days. On day 7, cells were evaluated for both the gene expression (RT-qPCR) of odontogenic markers (COL1A1, ALPL, DSPP, and DMP1) and cytokines (TNF, IL1B, IL8, and IL6) and the production of reactive nitrogen (Griess) and oxygen species (Carboxy-H2DCFDA). Cell viability (alamarBlue) was evaluated weekly, and mineralization was assessed (Alizarin Red) at 14 and 21 days. Data were analyzed with ANOVA and post-hoc tests (α=5%). Results After one and seven days of exposure to LPS, NF-κB was activated in a dose-dependent fashion. LPS at 1 and 10 µg/mL concentrations down-regulated the gene expression of odontogenic markers and up-regulated cytokines. LPS at 10 µg/mL increased both the production of reactive nitrogen and oxygen species. LPS decreased cell viability seven days after the end of exposure. LPS at 1 and 10 µg/mL decreased hDPCs mineralization in a dose-dependent fashion. Conclusion The exposure to 10 µg/mL LPS for seven days creates an inflammatory environment that is able to impair by more than half the odontogenic potential of HDPCs in vitro, simulating a pulpitis-like condition.

Evaluación in vivo de la pirogenicidad de bioproductos fúngicos con potencial prebiótico / In vivo pyrogenicity evaluation of fungal bioproducts with prebiotic potential / Avaliação in vivo da pirogenicidade de bioprodutos fúngicos com potencial prebiótico

RESUMEN Introducción: Los productos naturales con actividad farmacológica requieren de evaluaciones preclínicas que justifiquen su empleo sobre una base científica. El ensayo de pirógenos es una prueba dentro de la Farmacología de Seguridad que se realiza para determinar la presencia de endotoxinas y constituye un método valioso, para demostrar la seguridad de bioderivados con potencial prebiótico en el campo de la inmunonutrición. Objetivo: Evaluar la pirogenicidad de bioproductos fúngicos de Pleurotus ostreatus (extractos acuosos del micelio y cuerpos fructíferos) y un biopreparado de levadura Kluyveromyces marxianus, empleando el ensayo de pirógenos en conejos Nueva Zelanda. Método: Se ensayaron concentraciones de 1,0 y 10,0 mg/mL de cada muestra por vía endovenosa en dosis de 0,5 y 5,0 mg/kg de peso. El diseño experimental cumplió las buenas prácticas de laboratorio según lo establecido por el International Council for Laboratory Animals Science y se realizó de acuerdo a los procedimientos normalizados de trabajo del Centro de Toxicología y Biomedicina, Santiago de Cuba. Resultados: Los extractos de Pleurotus ostreatus y el biopreparado de levadura (0,5 mg/kg) no mostraron signos de pirogenicidad. En los resultados del biopreparado (5,0 mg/kg), los valores de temperatura caen en un rango de incertidumbre, según la Farmacopea de Estados Unidos (USP) y se sugirió repetir el estudio. Conclusiones: Los extractos de Pleurotus ostreatus y el biopreparado de Kluyveromyces marxianus (0,5 mg/kg) no indujeron un aumento de temperatura significativo en los animales, lo cual sugiere que en estos bioproductos no existen niveles de endotoxinas que puedan provocar pirogenicidad.

ABSTRACT Introduction: Natural products with pharmacological activity require preclinical evaluations to justify their uses scientifically. The pyrogen assay is a safety pharmacology test performed to determine the presence of endotoxins and it is a valuable method to demonstrate the bio-derivative products safety and their prebiotic potential in the field of immunonutrition. Objective: To evaluate the pyrogenicity of fungal bioproducts from Pleurotus ostreatus (aqueous extracts from mycelium and fruiting bodies) and a biopreparation from Kluyveromyces marxianus yeast, using a pyrogen assay in New Zealand rabbits. Method: Concentrations of 1.0 and 10.0 mg/mL of each sample were tested intravenously at doses of 0.5 and 5.0 mg/kg body weight. The experimental design complied with good laboratory practices as established by the International Council for Laboratory Animal Science and was carried out according to the standard work procedures of the Centro de Toxicología y Biomedicina, Santiago de Cuba. Results: Pleurotus ostreatus extracts and the yeast biopreparation (0.5 mg/kg) showed no signs of pyrogenicity. In the biopreparation results (5.0 mg/kg), temperature values fall in the uncertainty range according to the United States Pharmacopoeia (USP), and therefore it was suggested to repeat the study. Conclusions: Pleurotus ostreatus extracts and Kluyveromyces marxianus biopreparation (0.5 mg/kg) did not induce a significant temperature increase in the animals, thereby suggesting that there are no endotoxin levels in such bioproducts that could cause pyrogenicity.

RESUMO Introdução: Produtos naturais com atividade farmacológica requerem avaliações pré-clínicas que justifiquem seu uso em bases científicas. O ensaio de pirogênio é um teste dentro da Farmacologia de Segurança que é realizado para determinar a presença de endotoxinas e é um método valioso para demonstrar a segurança de bioderivados com potencial prebiótico no campo da imunonutrição. Objetivo: Avaliar a pirogenicidade de bioprodutos fúngicos de Pleurotus ostreatus (extratos aquosos do micélio e corpos de frutificação) e de uma biopreparação da levedura Kluyveromyces marxianus, utilizando o ensaio pirogênico de coelho da Nova Zelândia. Método: Concentrações de 1,0 e 10,0 mg/mL de cada amostra foram testadas por via intravenosa nas doses de 0,5 e 5,0 mg/kg de peso. O desenho experimental obedeceu às boas práticas laboratoriais estabelecidas pelo Conselho Internacional para a Ciência dos Animais de Laboratório e foi realizado de acordo com os procedimentos de trabalho padrão do Centro de Toxicologia e Biomedicina, Santiago de Cuba. Resultados: Os extratos de Pleurotus ostreatus e a biopreparação de leveduras (0,5 mg/kg) não apresentaram sinais de pirogenicidade. Nos resultados da biopreparação (5,0 mg/kg), os valores de temperatura estão dentro de uma faixa de incerteza, segundo a Farmacopeia dos Estados Unidos (USP) e foi sugerido repetir o estudo. Conclusões: Os extratos de Pleurotus ostreatus e a biopreparação de Kluyveromyces marxianus (0,5 mg/kg) não induziram um aumento significativo da temperatura nos animais, o que sugere que não há níveis de endotoxinas nesses bioprodutos que possam causar pirogenicidade.

Research on Syringin protecting C2C12 myotube viability through regulating NF- κB/PPAR γ1 pathway / 国际中医中药杂志

Objective:To discuss the protective effect of Syringin (SYR) on myotube cell atrophy induced by lipopolysaccharide (LPS) and its molecular mechanism.Methods:After C2C12 myoblasts were differentiated into myotubes, they were divided into normal control group, model group and syringin group according to the random number table method. The cultured medium of model group and syringin group were added with LPS with a concentration of 200 ng/ml; the cultured medium of the syringin group was also added with 10 μmol/L syringin for 24 h. CCK8 was used to detect cell viability. In cell supernatant, NO release was detected with Griess and TNF-α level was detected by ELISA kit. The expression of NF-κB, PPAR γ1, MyHC were detected by Western blot.Results:Compared with the model group, the viability of cells [(101.08±8.92)%, (79.53±5.19)% vs. (69.07±7.16)%] in the 10 μmol/L and 100 μmol/L syringin groups were significantly increased ( P<0.01 or P<0.01), of which 10 μmol/L syringin had better effect. Compared with the model group, the level of NO [(2.92±0.33) μmol/L vs. (3.57±0.41) μmol/L] in the syringin group was significantly decreased after 6 hours of intervention ( P<0.01), and the cells in the syringin group after 24 hours of intervention, the level of TNF-α [(2.73±0.29) pg/ml vs. (4.15±0.29) pg/ml] was significantly decreased ( P<0.01), and the protein expression of cellular NF-κB (0.95±0.24 vs. 1.16±0.28) was significantly decreased ( P<0.05), the protein expression of MyHC (0.79±0.15 vs. 0.70±0.16) was increased ( P<0.05). Conclusion:SYR could inhibit the inflammatory response induced by LPS, promote the activity of myotubes, and antagonize the damage of LPS to myotube cells.

Effect of electrical stimulation on lipopolysaccharide-induced activation of M1 microglia / 中华麻醉学杂志

Objective:To evaluate the effect of electrical stimulation on lipopolysaccharide (LPS)-induced activation of M1 microglia.Methods:The well-growing BV2 microglia cells were divided into 3 groups ( n=18 each) using a random number table method: control group (group C), group LPS, LPS and electrical stimulation group (group LE). The cells were cultured for 24 h in normal culture atmosphere in group C. In group LPS and group LE, the LPS medium culture 100 ng/ml was added, and the cells were cultured for 24 h. In group LE, cells were stimulated with 100 mV/mm direct current for 4 h before LPS incubation.The levels of tumor necrosis factor-α (TNF-α) and leukocyte interleukin-1β (IL-1β) were determined by enzyme-linked immunosorbent assay.The expression of the M1 microglia surface markers CD32 and inducible nitric oxide synase (iNOS) was detected using immunofluorescent staining.The expression of CD32 and iNOS mRNA was detected using quantitative real-time polymerase chain reaction. Results:Compared with group C, the concentrations of TNF-α and IL-1β were significantly increased, and the expression of CD32 and iNOS protein and mRNA was up-regulated in LPS and LE groups ( P<0.05). Compared with group LPS, the concentrations of TNF-α and IL-1β were significantly decreased, and the expression of CD32 and iNOS protein and mRNA was down-regulated in group LE ( P<0.05). Conclusions:Electrical stimulation can inhibit LPS-induced activation of M1 microglia and thus alleviate the inflammatory responses.

Interleukin 33 inhibits lipopolysaccharide-induced high permeability of cardiac microvascular endothelial cells / 中华内科杂志

Objective:To investigate the effect of interleukin-33 (IL-33) on lipopolysaccharide (LPS)-induced permeability of rat cardiac microvascular endothelial cells (RCMECs).Methods:RCMECs were cultured in vitro to be divided into control group, LPS group, IL-33 group and LPS+IL-33 group. The effect of IL-33 on the proliferation of RCMECs was detected by cell counting reagent (CCK8). Fluorescein isothiocyanate (FITC)-dextran assay was used to evaluate the permeability of RCMECs. The expression of vascular endothelial calmodulin, ras homologous gene family (Rho) member A (RhoA) and phosphorylated Rho-associated coiled-coil-containing protein kinase (p-ROCK2) proteins were tested by western blot. High-throughput sequencing and gene ontology (GO) were performed for gene expression in LPS and LPS+IL-33 groups.Results:No significant effect of IL-33 at 10-50 ng/ml on the proliferation of RCMECs was observed ( P>0.05). Compared with the control group, the permeability of RCMECs (permeability coefficient ratio 1.404±0.029 vs. 1.000±0.200, P<0.05) was significantly increased in LPS group and the expression of vascular endothelial calmodulin (relative gray value 0.429 5±0.012 9 vs. 0.594 9±0.014 2, P<0.05) was down-regulated, while the permeability of monolayers (permeability coefficient ratio, 0.948±0.013, P<0.01) was decreased in LPS+IL-33 group and the expression of vascular endothelial calmodulin (relative grayscale value 0.549 1±0.012 0, P<0.005) was up-regulated compared with the LPS group. High-throughput sequencing data revealed that the differential genes downregulated in the LPS and LPS+IL-33 groups were associated with cytoskeleton and Rho signaling pathway. Compared with the control group, RhoA (relative gray value 0.211 4±0.009 9 vs. 0.135 0±0.007 6, P<0.000 1) and p-ROCK (relative gray value 0.656 3±0.013 2 vs. 0.503 6±0.036 2, P<0.000 1) protein expression was upregulated in the LPS group. When compared with LPS group, RhoA (relative gray value 0.157 7±0.010 7, P=0.000 2), p-ROCK (relative gray value 0.427 7±0.003 8, P<0.000 1) protein expression was decreased in LPS+IL-33 group. Conclusion:IL-33 may improve LPS-induced hyperpermeability of RCMECs by inhibiting RhoA and p-ROCK protein expression in Rho/Rho-associated coiled-coil-containing protein kinase signaling pathway.

Effect of Echinococcus multilocularis secreted antigen on the phenotype and function of mouse bone marrow - derived dendritic cells induced by lipopolysaccharide / 临床肝胆病杂志

Objective To investigate the effect of different concentrations of Echinococcus multilocularis secretion antigen (Em-sAg) on the phenotype and function of mouse bone marrow-derived dendritic cells (BMDCs) induced by lipopolysaccharide (LPS). Methods The bone marrow precursor cells isolated from the mouse bone marrow cavity were stimulated by mouse recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) to form BMDCs, and then cell morphology was observed under an inverted microscope. After the purity of BMDCs was identified by flow cytometry, BMDCs were divided into control group, positive control group (LPS 1 μg/ml), LPS+3 mg/ml Em-sAg group, LPS+1.5 mg/ml Em-sAg group, LPS+0.75 mg/ml Em-sAg group, and LPS+0.375 mg/ml Em-sAg group. Flow cytometry was used to measure the expression of BMDC surface molecules (CD80, CD86, and MHC-Ⅱ molecules) in each group, and ELISA was used to measure the expression level of the cytokine IL-12p70. A one-way analysis of variance was used for comparison of normally distributed continuous data between multiple groups, and the least significant difference t -test was used for further comparison between two groups. Results Observation under an inverted microscope showed that after 8-10 days of culture, the cells had burr-like protrusions and were in a state of complete suspension. Flow cytometry showed that the positive rate of CD11c was above 70% and most of the cultured cells were identified as BMDCs based on this. Flow cytometry further showed that compared with the control group, the LPS group had significant increases in the cell molecules CD80, CD86, and MHC-Ⅱ on surface (all P 0.05). ELISA showed that there was a significant difference in the level of IL-12 p70 between groups ( F =73.140, P < 0.05); compared with the control group, the LPS group had a significant increase in the expression level of IL-12p70 after stimulation ( P < 0.05); compared with the positive control group, the LPS+3 mg/ml Em-sAg group, the LPS+1.5 mg/ml Em-sAg group, the LPS+0.75 mg/ml Em-sAg group, and the LPS+0.375 mg/ml Em-sAg group had a significant reduction in the expression level of IL-12p70 ( P < 0.05), and the degree of reduction in the pro-inflammatory factor IL-12p70 increased with the increase in the concentration of Em-sAg. Conclusion Different concentrations of Em-sAg can inhibit LPS-induced maturity of BMDCs and the expression of the pro-inflammatory cytokine IL-12p70.

Cloning and tissue expression analysis of the LepROT gene of Rana dybowskii / 生物工程学报

Leptin receptor overlapping transcript (LepROT) plays multiple roles in the regulation of immune systems. However, very little information is available about the anti-infectious mechanisms of amphibians LepROT. In this study, the cDNA sequence of the Rana dybowskii LepROT gene was determined by using RT-PCR and bioinformatics analysis. Then, the Aeromonas hydrophila (Ah) and lipopolysaccharides (LPS) infected models of R. dybowskii was constructed to obtain histopathological characteristics. Constitutive expression of LepROT mRNA and NF-κB signaling pathway were detected by real-time quantitative PCR. The full-length cDNA of LepROT gene was 396 bp and encoded 131 amino acids. Amino acid sequence analysis revealed LepROT shares 93.74% and 86.39% identity with homologues from other amphibians and mammals respectively, and the LepROT gene was quite conserved among different species. After infection, the relative expression levels of LepROT, NF-κB, IKKα and IKKβ mRNA were all significantly upregulated (P < 0.01), but showed a diverse temporal pattern of up-regulation in different tissues. Therefore, it was proposed that the LepROT gene of R. dybowskii might activate the NF-κB signaling pathway to exert anti-infectious effects, thus providing evidence for further extending the biological function of LepROT.

The role and mechanism of intestinal microbiota metabolites in Alzheimer′s disease / 中华神经科杂志

The intestinal microbiota refers to the microbial group that exists in the intestine, and its composition disorder may affect human health. Many studies have found that intestinal microbiota and their metabolites may be closely related to the pathologies of Alzheimer′s disease (AD) through the gut-brain axis. This article will review the roles and possible mechanisms of lipopolysaccharide, functional bacterial amyloid proteins and bile acids, which are common metabolites of intestinal microbiota, in the pathogenesis of AD, and provide valuable information for exploring the pathogenesis of AD.

Lipopolysaccharide preconditioning protects rats against cerebral ischemia reperfusion injury by reducing the damage of blood-brain barrier / 国际脑血管病杂志

Objective:To investigate the protective effect of lipopolysaccharide (LPS) preconditioning on cerebral ischemia reperfusion in rats.Methods:One hundred and twenty adult male SD rats were randomly divided into sham operation group, model group, low-dose LPS group (0.05 mg/kg), medium-dose LPS group (0.15 mg/kg), and high-dose LPS group (0.45 mg/kg). LPS was injected intraperitoneally for preconditioning, once a day for 7 consecutive days. Twenty-four hours after the last injection, the left middle cerebral artery occlusion model was induced by suture-occluded method. The model was reperfused 1.5 h after ischemia. At 24 h after reperfusion, the neurological deficit was evaluated by neurobehavioral score. The volume of cerebral infarction was measured by triphenyltetrazolium chloride staining. The serum levels of proinflammatory cytokines interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF)-α were detected by enzyme-linked immunosorbent assay. The expression of Toll-like receptor 4 (TLR4), matrix metalloproteinase (MMP) -2 and MMP-9 in ischemic brain tissue was detected by Western blot analysis.Results:Compared with the sham operation group, blood-brain barrier permeability was increased in the model group, serum IL-1β, IL-6 and TNF-α were up-regulated, and the expression of TLR4, MMP-2 and MMP-9 proteins in ischemic brain tissue was up-regulated. Compared with the model group, the neurological impairment of each LPS intervention group was significantly reduced, the volume of cerebral infarction was significantly reduced, the permeability of blood-brain barrier was significantly reduced, the serum IL-1β, IL-6 and TNF-α were down-regulated, and the expression of TLR4, MMP-2 and MMP-9 protein in ischemic brain tissue was down-regulated, especially in the medium-dose group and the high-dose group.Conclusions:LPS preconditioning can induce the formation of ischemic tolerance, inhibit the activation of TLR4-MMP-2/MMP-9 signal pathway, reduce the damage and inflammation of blood-brain barrier structure, and thus play a neuroprotective role in rats with cerebral ischemia reperfusion.