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1.
Toxins (Basel) ; 16(5)2024 May 07.
Article in English | MEDLINE | ID: mdl-38787067

ABSTRACT

Bacillus thuringiensis (Bt) secretes the nutritional insecticidal protein Vip3Aa11, which exhibits high toxicity against the fall armyworm (Spodoptera frugiperda). The Bt HD270 extracellular polysaccharide (EPS) enhances the toxicity of Vip3Aa11 protoxin against S. frugiperda by enhancing the attachment of brush border membrane vesicles (BBMVs). However, how EPS-HD270 interacts with Vip3Aa11 protoxin in vivo and the effect of EPS-HD270 on the toxicity of activated Vip3Aa11 toxin are not yet clear. Our results indicated that there is an interaction between mannose, a monosaccharide that composes EPS-HD270, and Vip3Aa11 protoxin, with a dissociation constant of Kd = 16.75 ± 0.95 mmol/L. When EPS-HD270 and Vip3Aa11 protoxin were simultaneously fed to third-instar larvae, laser confocal microscopy observations revealed the co-localization of the two compounds near the midgut wall, which aggravated the damage to BBMVs. EPS-HD270 did not have a synergistic insecticidal effect on the activated Vip3Aa11 protein against S. frugiperda. The activated Vip3Aa11 toxin demonstrated a significantly reduced binding capacity (548.73 ± 82.87 nmol/L) towards EPS-HD270 in comparison to the protoxin (34.96 ± 9.00 nmol/L). Furthermore, this activation diminished the affinity of EPS-HD270 for BBMVs. This study provides important evidence for further elucidating the synergistic insecticidal mechanism between extracellular polysaccharides and Vip3Aa11 protein both in vivo and in vitro.


Subject(s)
Bacterial Proteins , Polysaccharides, Bacterial , Spodoptera , Animals , Bacterial Proteins/toxicity , Bacterial Proteins/metabolism , Polysaccharides, Bacterial/pharmacology , Polysaccharides, Bacterial/chemistry , Spodoptera/drug effects , Larva/drug effects , Insecticides/toxicity , Insecticides/pharmacology , Bacillus thuringiensis/metabolism , Microvilli/metabolism , Microvilli/drug effects
2.
Nutrients ; 14(1)2022 Jan 05.
Article in English | MEDLINE | ID: mdl-35011095

ABSTRACT

Saffron (Crocus sativus L.) is known as the most expensive spice. C. sativus dried red stigmas, called threads, are used for culinary, cosmetic, and medicinal purposes. The rest of the flower is often discarded, but is now being used in teas, as coloring agents, and fodder. Previous studies have attributed antioxidant, anti-inflammatory, hepatoprotective, neuroprotective, anti-depressant, and anticancer properties to C. sativus floral bio-residues. The aim of this study is to assess C. sativus flower water extract (CFWE) for its effects on hemoglobin, brush boarder membrane (BBM) functionality, morphology, intestinal gene expression, and cecal microbiome in vivo (Gallus gallus), a clinically validated model. For this, Gallus gallus eggs were divided into six treatment groups (non-injected, 18 Ω H2O, 1% CFWE, 2% CFWE, 5% CFWE, and 10% CFWE) with n~10 for each group. On day 17 of incubation, 1 mL of the extracts/control were administered in the amnion of the eggs. The amniotic fluid along with the administered extracts are orally consumed by the developing embryo over the course of the next few days. On day 21, the hatchlings were euthanized, the blood, duodenum, and cecum were harvested for assessment. The results showed a significant dose-dependent decrease in hemoglobin concentration, villus surface area, goblet cell number, and diameter. Furthermore, we observed a significant increase in Paneth cell number and Mucin 2 (MUC2) gene expression proportional to the increase in CFWE concentration. Additionally, the cecum microbiome analysis revealed C. sativus flower water extract altered the bacterial populations. There was a significant dose-dependent reduction in Lactobacillus and Clostridium sp., suggesting an antibacterial effect of the extract on the gut in the given model. These results suggest that the dietary consumption of C. sativus flower may have negative effects on BBM functionality, morphology, mineral absorption, microbial populations, and iron status.


Subject(s)
Cecum/microbiology , Crocus/chemistry , Flowers/chemistry , Gastrointestinal Microbiome/drug effects , Microvilli/drug effects , Plant Extracts/pharmacology , Animals , Chickens
3.
Appl Environ Microbiol ; 87(24): e0178721, 2021 11 24.
Article in English | MEDLINE | ID: mdl-34586902

ABSTRACT

Vegetative insecticidal proteins (Vip3) from Bacillus thuringiensis have been used, in combination with Cry proteins, to better control insect pests and as a strategy to delay the evolution of resistance to Cry proteins in Bt crops (crops protected from insect attack by the expression of proteins from B. thuringiensis). In this study, we have set up the conditions to analyze the specific binding of 125I-Vip3Af to Spodoptera frugiperda and Spodoptera exigua brush border membrane vesicles (BBMV). Heterologous competition binding experiments revealed that Vip3Aa shares the same binding sites with Vip3Af, but Vip3Ca does not recognize all of them. As expected, Cry1Ac and Cry1F did not compete for Vip3Af binding sites. By trypsin treatment of selected alanine mutants, we were able to generate truncated versions of Vip3Af. Their use as competitors with 125I-Vip3Af indicated that only those molecules containing domains I to III (DI-III and DI-IV) were able to compete with the trypsin-activated Vip3Af protein for binding and that molecules only containing either domain IV or domains IV and V (DIV and DIV-V) were unable to compete with Vip3Af. These results were further confirmed with competition binding experiments using 125I-DI-III. In addition, the truncated protein 125I-DI-III also bound specifically to Sf21 cells. Cell viability assays showed that the truncated proteins DI-III and DI-IV were as toxic to Sf21 cells as the activated Vip3Af, suggesting that domains IV and V are not necessary for the toxicity to Sf21 cells, in contrast to their requirement in vivo.IMPORTANCE This study shows that Vip3Af binding sites are fully shared with Vip3Aa, only partially shared with Vip3Ca, and not shared with Cry1Ac and Cry1F in two Spodoptera spp. Truncated versions of Vip3Af revealed that only domains I to III were necessary for the specific binding, most likely because they can form the functional tetrameric oligomer and because domain III is supposed to contain the binding epitopes. In contrast to results obtained in vivo (bioassays against larvae), domains IV and V are not necessary for ex vivo toxicity to Sf21 cells.


Subject(s)
Bacterial Proteins/chemistry , Insecticides , Microvilli/drug effects , Spodoptera/drug effects , Animals , Bacillus thuringiensis , Binding Sites , Cell Line , Protein Binding , Trypsin
4.
Int J Biol Macromol ; 189: 956-964, 2021 Oct 31.
Article in English | MEDLINE | ID: mdl-34478795

ABSTRACT

Bacillus thuringiensis (Bt) are entomopathogenic bacteria that produce different kinds of insecticidal proteins. However, studies on Bt exopolysaccharides are lacking. Here, we aimed to explore the characteristics and insecticidal synergism of EPS, an exopolysaccharide from Bt strain 4D19. The molecular weight of EPS-2 was 58.0 kDa, which consisted of mannose (44.2%), GlcN (35.5%), D-GalN (8.0%), glucose (5.5%), arabinose (5.1%), galactose (0.9%), Man-UA (0.3%) and Glc-UA (0.2%). The toxicity of insecticidal proteins against Plutella xylostella was increased by adding EPS. EPS-2 bound to Cry1Ac protoxin and promoted the binding of Cry1Ac protoxin to the gut membrane of P. xylostella, but did not bind to activated toxins. These results suggested that EPS-2 may bind to the protoxin C-terminal region to enhance insecticidal activity. Our findings indicated that Bt strains produce exopolysaccharide to enhance the toxicity of insecticidal crystal proteins, which could be applied in biopesticide research and product development.


Subject(s)
Bacillus thuringiensis/chemistry , Polysaccharides/chemistry , Polysaccharides/pharmacology , Animals , Bacillus thuringiensis Toxins/toxicity , Biological Assay , Endotoxins/toxicity , Hemolysin Proteins/toxicity , Microvilli/drug effects , Microvilli/metabolism , Molecular Weight , Monosaccharides/analysis , Moths/drug effects , Polysaccharides/isolation & purification , Protein Binding/drug effects
5.
Hum Cell ; 34(6): 1709-1716, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34312810

ABSTRACT

Mechanical stiffness is closely related to cell adhesion and rounding in some cells. In leukocytes, dephosphorylation of ezrin/radixin/moesin (ERM) proteins is linked to cell adhesion events. To elucidate the relationship between surface stiffness, cell adhesion, and ERM dephosphorylation in leukocytes, we examined the relationship in the myelogenous leukemia line, KG-1, by treatment with modulation drugs. KG-1 cells have ring-shaped cortical actin with microvilli as the only F-actin cytoskeleton, and the actin structure constructs the mechanical stiffness of the cells. Phorbol 12-myristate 13-acetate and staurosporine, which induced cell adhesion to fibronectin surface and ERM dephosphorylation, caused a decrease in surface stiffness in KG-1 cells. Calyculin A, which inhibited ERM dephosphorylation and had no effect on cell adhesion, did not affect surface stiffness. To clarify whether decreasing cell surface stiffness and inducing cell adhesion are equivalent, we examined KG-1 cell adhesion by treatment with actin-attenuated cell softening reagents. Cytochalasin D clearly diminished cell adhesion, and high concentrations of Y27632 slightly induced cell adhesion. Only Y27632 slightly decreased ERM phosphorylation in KG-1 cells. Thus, decreasing cell surface stiffness and inducing cell adhesion are not equivalent, but these phenomena are coordinately regulated by ERM dephosphorylation in KG-1 cells.


Subject(s)
Cell Adhesion/drug effects , Cell Adhesion/physiology , Cytoskeletal Proteins/metabolism , Elasticity/physiology , Leukemia, Myeloid/pathology , Leukocytes/metabolism , Leukocytes/physiology , Membrane Proteins/metabolism , Microfilament Proteins/metabolism , Actins/metabolism , Amides/pharmacology , Cell Adhesion/genetics , Cell Line, Tumor , Cytochalasin D/pharmacology , Elasticity/drug effects , Fibronectins/metabolism , Humans , Leukemia, Myeloid/metabolism , Microvilli/drug effects , Microvilli/metabolism , Phorbol Esters/pharmacology , Phosphorylation/drug effects , Pyridines/pharmacology , Staurosporine/pharmacology
6.
Toxicology ; 460: 152873, 2021 08.
Article in English | MEDLINE | ID: mdl-34303734

ABSTRACT

Oxidative stress (OS) is a key factor in the development of gastrointestinal disorders, in which the intestinal barrier is altered. However, the Multidrug resistance-associated protein 2 (Mrp2) status, an essential component of the intestinal transcellular barrier exhibiting pharmaco-toxicological relevance by limiting the orally ingested toxicants and drugs absorption, has not been investigated. We here evaluated the short-term effect of OS on Mrp2 by treatment of isolated rat intestinal sacs with tert-butyl hydroperoxide (TBH) for 30 min. OS induction by TBH (250 and 500 µM) was confirmed by increased lipid peroxidation end products, decreased reduced glutathione (GSH) content and altered antioxidant enzyme activities. Under this condition, assessment of Mrp2 distribution between brush border (BBM) and intracellular (IM) membrane fractions, showed that Mrp2 protein decreased in BBM and increased in IM, consistent with an internalization process. This was associated with decreased efflux activity and, consequently, impaired barrier function. Subsequent incubation with N-Acetyl-L-Cysteine (NAC, 1 mM) reestablished GSH content and reverted concomitantly the alteration in Mrp2 localization and function induced by TBH. Cotreatment with a specific inhibitor of classic calcium-dependent Protein Kinase C (cPKC) implicated this kinase in TBH-effects. In conclusion, we demonstrated a negative posttranslational regulation of rat intestinal Mrp2 after short-term exposition to OS, a process likely mediated by cPKC and dependent on intracellular GSH content. The concomitant impairment of the Mrp2 barrier function may have implications in xenobiotic absorption and toxicity in a variety of human diseases linked to OS, with notable consequences on the toxicity/safety of therapeutic agents.


Subject(s)
ATP-Binding Cassette Transporters/metabolism , Intestinal Mucosa/metabolism , Jejunum/metabolism , Microvilli/metabolism , Oxidative Stress/physiology , Protein Processing, Post-Translational/physiology , Animals , Dose-Response Relationship, Drug , Intestinal Mucosa/drug effects , Jejunum/drug effects , Male , Microvilli/drug effects , Oxidative Stress/drug effects , Protein Processing, Post-Translational/drug effects , Rats , Rats, Wistar , tert-Butylhydroperoxide/toxicity
7.
Food Funct ; 12(14): 6157-6166, 2021 Jul 20.
Article in English | MEDLINE | ID: mdl-34079965

ABSTRACT

The intra-amniotic administration approach has been used to evaluate the effects of plant origin prebiotics on intestinal health and on brush border membrane functionality and morphology. Prebiotics are fermentable dietary fibers, which can positively affect the host by selectively stimulating the growth and activity of colon bacteria, thus improving intestinal health. The consumption of prebiotics increases digestive tract motility, which leads to hyperplasia and/or hypertrophy of intestinal cells, increasing nutrient digestive and absorptive surface area. This review collates information about the effects and relationship between prebiotic consumption on small intestinal brush border membrane functionality and morphology by utilizing the intra-amniotic administration approach. To date, research has shown that the intra-amniotic administration of prebiotics affects the expression of key brush border membrane functional proteins, intestinal surface area (villi height/width), and goblet cell number/size. These effects may improve brush border membrane functionality and digestive/absorptive capabilities.


Subject(s)
Chickens , Intestinal Mucosa/drug effects , Microvilli/drug effects , Plant Extracts/pharmacology , Prebiotics/administration & dosage , Animals , Colon/microbiology , Dietary Fiber/administration & dosage , Digestion , Duodenum/metabolism , Duodenum/microbiology , Gastrointestinal Microbiome/drug effects , Gastrointestinal Motility , Gastrointestinal Tract/metabolism , Gastrointestinal Tract/microbiology , Intestinal Absorption , Intestinal Mucosa/metabolism , Intestines/microbiology , Microvilli/metabolism
8.
Cells ; 10(3)2021 03 21.
Article in English | MEDLINE | ID: mdl-33801010

ABSTRACT

In Inflammatory Bowel Disease (IBD), malabsorption of electrolytes (NaCl) results in diarrhea. Inhibition of coupled NaCl absorption, mediated by the dual operation of Na:H and Cl:HCO3 exchangers on the brush border membrane (BBM) of the intestinal villus cells has been reported in IBD. In the SAMP1/YitFcs (SAMP1) mice model of spontaneous ileitis, representing Crohn's disease, DRA (Downregulated in Adenoma) mediated Cl:HCO3 exchange was shown to be inhibited secondary to diminished affinity of the exchanger for Cl. However, NHE3 mediated Na:H exchange remained unaffected. Mast cells and their secreted mediators are known to be increased in the IBD mucosa and can affect intestinal electrolyte absorption. However, how mast cell mediators may regulate Cl:HCO3 exchange in SAMP1 mice is unknown. Therefore, the aim of this study was to determine the effect of mast cell mediators on the downregulation of DRA in SAMP1 mice. Mast cell numbers and their degranulation marker enzyme (ß-hexosaminidase) levels were significantly increased in SAMP1 mice compared to control AKR mice. However, treatment of SAMP1 mice with a mast cell stabilizer, ketotifen, restored the ß-hexosaminidase enzyme levels to normal in the intestine, demonstrating stabilization of mast cells by ketotifen. Moreover, downregulation of Cl:HCO3 exchange activity was restored in ketotifen treated SAMP1 mice. Kinetic studies showed that ketotifen restored the altered affinity of Cl:HCO3 exchange in SAMP1 mice villus cells thus reinstating its activity to normal. Further, RT-qPCR, Western blot and immunofluorescence studies showed that the expression levels of DRA mRNA and BBM protein, respectively remained unaltered in all experimental conditions, supporting the kinetic data. Thus, inhibition of Cl:HCO3 exchange resulting in chloride malabsorption leading to diarrhea in IBD is likely mediated by mast cell mediators.


Subject(s)
Chlorides/metabolism , Ileitis/metabolism , Intestinal Absorption , Intestine, Small/metabolism , Mast Cells/metabolism , Animals , Antiporters/genetics , Antiporters/metabolism , Bicarbonates/metabolism , Cell Degranulation/drug effects , Chronic Disease , Disease Models, Animal , Ileum/drug effects , Ileum/metabolism , Ileum/pathology , Inflammation/pathology , Intestinal Absorption/drug effects , Intestinal Mucosa/drug effects , Intestinal Mucosa/enzymology , Intestinal Mucosa/pathology , Ketotifen/pharmacology , Kinetics , Male , Mast Cells/drug effects , Mast Cells/physiology , Mice , Microvilli/drug effects , Microvilli/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Sodium-Hydrogen Exchangers/metabolism , Sulfate Transporters/genetics , Sulfate Transporters/metabolism , beta-N-Acetylhexosaminidases/metabolism
9.
Nutrients ; 13(4)2021 Apr 17.
Article in English | MEDLINE | ID: mdl-33920564

ABSTRACT

Intestinal health relies on the association between the mucosal immune system, intestinal barrier and gut microbiota. Bioactive components that affect the gut microbiota composition, epithelial physical barrier and intestinal morphology were previously studied. The current systematic review evaluated evidence of anthocyanin effects and the ability to improve gut microbiota composition, their metabolites and parameters of the physical barrier; this was conducted in order to answer the question: "Does food source or extract of anthocyanin promote changes on intestinal parameters?". The data analysis was conducted following the PRISMA guidelines with the search performed at PubMed, Cochrane and Scopus databases for experimental studies, and the risk of bias was assessed by the SYRCLE tool. Twenty-seven studies performed in animal models were included, and evaluated for limitations in heterogeneity, methodologies, absence of information regarding allocation process and investigators' blinding. The data were analyzed, and the anthocyanin supplementation demonstrated positive effects on intestinal health. The main results identified were an increase of Bacteroidetes and a decrease of Firmicutes, an increase of short chain fatty acids production, a decrease of intestinal pH and intestinal permeability, an increase of the number of goblet cells and tight junction proteins and villi improvement in length or height. Thus, the anthocyanin supplementation has a potential effect to improve the intestinal health. PROSPERO (CRD42020204835).


Subject(s)
Anthocyanins/pharmacokinetics , Dietary Supplements , Gastrointestinal Microbiome/drug effects , Intestinal Mucosa/drug effects , Intestines/drug effects , Bacteroidetes/metabolism , Biological Availability , Fatty Acids, Volatile/biosynthesis , Firmicutes/metabolism , Goblet Cells/metabolism , Humans , Microvilli/drug effects , Permeability/drug effects
10.
Oxid Med Cell Longev ; 2021: 6610726, 2021.
Article in English | MEDLINE | ID: mdl-33613823

ABSTRACT

Exposure to total body irradiation (TBI) causes dose- and tissue-specific lethality. However, there are few effective and nontoxic radiation countermeasures for the radiation injury. In the current study, mice were pretreated with a traditional antimicrobial agent, FZD, before TBI; the protective effects of FZD on radiation injury were evaluated by using parameters such as the spleen index and thymus index, immunohistochemical staining of intestinal tissue, and frequency of micronuclei in polychromatophilic erythrocytes of bone marrow. The intestinal epithelial cell line IEC-6 was used to investigate the underlying mechanisms. Our results indicated that FZD administration significantly improved the survival of lethal dose-irradiated mice, decreased the number of micronuclei, upregulated the number of leukocytes and immune organ indices, and restored intestinal integrity in mice after TBI. TUNEL and western blot showed that FZD protected intestinal tissue by downregulating radiation-induced apoptosis and autophagy. Meanwhile, FZD protected IEC-6 cells from radiation-induced cell death by inhibiting apoptosis and autophagy. To sum up, FZD protected against radiation-induced cell death both in vitro and in vivo through antiapoptosis and antiautophagy mechanisms.


Subject(s)
Apoptosis , Autophagy , Furazolidone/therapeutic use , Radiation Injuries, Experimental/drug therapy , Radiation Injuries, Experimental/pathology , Whole-Body Irradiation , Animals , Apoptosis/drug effects , Apoptosis/radiation effects , Autophagy/drug effects , Autophagy/radiation effects , Cell Cycle Checkpoints/drug effects , Cell Cycle Checkpoints/radiation effects , Cell Line , Furazolidone/chemistry , Furazolidone/pharmacology , Hematopoiesis/drug effects , Hematopoiesis/radiation effects , Intestines/drug effects , Intestines/pathology , Intestines/radiation effects , Male , Mice, Inbred ICR , Microvilli/drug effects , Microvilli/pathology , Microvilli/radiation effects , Radiation Tolerance/drug effects , Radiation Tolerance/radiation effects , Radiation, Ionizing , Radiation-Protective Agents/chemistry , Radiation-Protective Agents/pharmacology , Radiation-Protective Agents/therapeutic use , Survival Analysis , Time Factors
11.
Int J Mol Sci ; 23(1)2021 Dec 28.
Article in English | MEDLINE | ID: mdl-35008753

ABSTRACT

Postprandial hyperglycemia is an important causative factor of type 2 diabetes mellitus, and permanent localization of intestinal GLUT2 in the brush border membrane is an important reason of postprandial hyperglycemia. Berberine, a small molecule derived from Coptidis rhizome, has been found to be potent at lowering blood glucose, but how berberine lowers postprandial blood glucose is still elusive. Here, we investigated the effect of berberine on intestinal glucose transporter 2 (GLUT2) translocation and intestinal glucose absorption in type 2 diabetes mouse model. Type 2 diabetes was induced by feeding of a high-fat diet and injection of streptozotocin and diabetic mice were treated with berberine for 6 weeks. The effects of berberine on intestinal glucose transport and GLUT2 translocation were accessed in isolated intestines and intestinal epithelial cells (IEC-6), respectively. We found that berberine treatment improved glucose tolerance and systemic insulin sensitivity in diabetic mice. Furthermore, berberine decreased intestinal glucose transport and inhibited GLUT2 translocation from cytoplasm to brush border membrane in intestinal epithelial cells. Mechanistically, berberine inhibited intestinal insulin-like growth factor 1 (IGF-1R) phosphorylation and thus reduced localization of PLC-ß2 in the membrane, leading to decreased GLUT2 translocation. These results suggest that berberine reduces intestinal glucose absorption through inhibiting IGF-1R-PLC-ß2-GLUT2 signal pathway.


Subject(s)
Berberine/pharmacology , Glucose Transporter Type 2/metabolism , Glucose/metabolism , Intestinal Absorption , Intestines/metabolism , Animals , Blood Glucose/metabolism , Body Weight/drug effects , Cell Line , Diabetes Mellitus, Experimental/blood , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Experimental/pathology , Epithelial Cells/drug effects , Epithelial Cells/metabolism , Fasting/blood , Hyperglycemia/pathology , Insulin Resistance , Insulin-Like Growth Factor Binding Protein 3 , Insulin-Like Growth Factor I/metabolism , Intestinal Absorption/drug effects , Mice, Inbred C57BL , Microvilli/drug effects , Microvilli/metabolism , Models, Biological , Protein Transport/drug effects , Receptor, IGF Type 1/metabolism , Signal Transduction/drug effects , Type C Phospholipases/metabolism
12.
Front Immunol ; 11: 2187, 2020.
Article in English | MEDLINE | ID: mdl-33013920

ABSTRACT

Microvilli are finger-like membrane protrusions, supported by the actin cytoskeleton, and found on almost all cell types. A growing body of evidence suggests that the dynamic lymphocyte microvilli, with their highly curved membranes, play an important role in signal transduction leading to immune responses. Nevertheless, challenges in modulating local membrane curvature and monitoring the high dynamicity of microvilli hampered the investigation of the curvature-generation mechanism and its functional consequences in signaling. These technical barriers have been partially overcome by recent advancements in adapted super-resolution microscopy. Here, we review the up-to-date progress in understanding the mechanisms and functional consequences of microvillus formation in T cell signaling. We discuss how the deformation of local membranes could potentially affect the organization of signaling proteins and their biochemical activities. We propose that curved membranes, together with the underlying cytoskeleton, shape microvilli into a unique compartment that sense and process signals leading to lymphocyte activation.


Subject(s)
Cell Membrane/immunology , Lymphocyte Activation/physiology , Microvilli/immunology , Signal Transduction/immunology , T-Lymphocytes/ultrastructure , Actin Cytoskeleton/drug effects , Actin Cytoskeleton/ultrastructure , Animals , Carrier Proteins/pharmacology , Cell Line , Cell Membrane/drug effects , Cell Membrane/ultrastructure , Cell Shape , Cyclodextrins/pharmacology , Cytokines/physiology , Glycocalyx/drug effects , Glycocalyx/immunology , Humans , Lymphocyte Activation/drug effects , Membrane Lipids/immunology , Membrane Proteins/immunology , Mice , Microfilament Proteins/pharmacology , Microscopy, Electron, Scanning , Microvilli/drug effects , Microvilli/ultrastructure , Receptors, Antigen, T-Cell/immunology , Signal Transduction/drug effects , Stress, Mechanical , Surface Properties , Synaptosomes/drug effects , Synaptosomes/immunology , Synaptosomes/ultrastructure , T-Lymphocytes/drug effects , T-Lymphocytes/immunology
13.
J Cell Mol Med ; 24(21): 12848-12861, 2020 11.
Article in English | MEDLINE | ID: mdl-33029898

ABSTRACT

The farnesoid X receptor (FXR), as a bile acid (BA) sensor, plays an important role in the regulation of lipid metabolism. However, the effects and underlying molecular mechanisms of FXR on intestinal glucose homeostasis remain elusive. Herein, we demonstrated that FXR and glucose transporter 2 (GLUT2) are essential for BA-mediated glucose homeostasis in the intestine. BA-activated FXR enhanced glucose uptake in intestinal epithelial cells by increasing the expression of GLUT2, which depended on ERK1/2 phosphorylation via S1PR2. However, it also reduced the cell energy generation via inhibition of oxidative phosphorylation, which is crucial for intestinal glucose transport. Moreover, BA-activated FXR signalling potently inhibited specific glucose flux through the intestinal epithelium to the circulation, which reduced the increase in blood glucose levels in mice following oral glucose administration. This trend was supported by the changed ratio of GLUT2 to SGLT1 in the brush border membrane (BBM), including especially decreased GLUT2 abundance in the BBM. Furthermore, impaired intestinal FXR signalling was observed in the patients with intestinal bile acid deficiency (IBAD). These findings uncover a novel function by which FXR sustains the intestinal glucose homeostasis and provide a rationale for FXR agonists in the treatment of IBAD-related hyperglycaemia.


Subject(s)
Bile Acids and Salts/metabolism , Glucose/metabolism , Homeostasis , Intestines/physiology , Receptors, Cytoplasmic and Nuclear/metabolism , Animals , Biological Transport/drug effects , Cell Line , Chenodeoxycholic Acid/pharmacology , Extracellular Signal-Regulated MAP Kinases/metabolism , Glucose Transporter Type 2/metabolism , Homeostasis/drug effects , Humans , Intestines/drug effects , Male , Mice, Inbred C57BL , Microvilli/drug effects , Microvilli/metabolism , Phosphorylation/drug effects , Rats , Signal Transduction , Sphingosine-1-Phosphate Receptors/metabolism
14.
Nutrients ; 12(10)2020 Oct 02.
Article in English | MEDLINE | ID: mdl-33023112

ABSTRACT

The consumption of teff (Eragrostis tef), a gluten-free cereal grain, has increased due to its dense nutrient composition including complex carbohydrates, unsaturated fatty acids, trace minerals (especially Fe), and phytochemicals. This study utilized the clinically-validated Gallus gallus intra amniotic feeding model to assess the effects of intra-amniotic administration of teff extracts versus controls using seven groups: (1) non-injected; (2) 18Ω H2O injected; (3) 5% inulin; (4) teff extract 1%; (5) teff extract 2.5%; (6) teff extract 5%; and (7) teff extract 7.5%. The treatment groups were compared to each other and to controls. Our data demonstrated a significant improvement in hepatic iron (Fe) and zinc (Zn) concentration and LA:DGLA ratio without concomitant serum concentration changes, up-regulation of various Fe and Zn brush border membrane proteins, and beneficial morphological changes to duodenal villi and goblet cells. No significant taxonomic alterations were observed using 16S rRNA sequencing of the cecal microbiota. Several important bacterial metabolic pathways were differentially enriched in the teff group, likely due to teff's high relative fiber concentration, demonstrating an important bacterial-host interaction that contributed to improvements in the physiological status of Fe and Zn. Therefore, teff appeared to represent a promising staple food crop and should be further evaluated.


Subject(s)
Eragrostis , Gastrointestinal Microbiome/drug effects , Nutritional Status/drug effects , Plant Extracts/administration & dosage , Prebiotics/administration & dosage , Seeds , Amnion , Animals , Cecum/microbiology , Chickens , Gastrointestinal Microbiome/genetics , Injections , Intestinal Mucosa/metabolism , Iron/blood , Magnesium/blood , Microvilli/drug effects , RNA, Ribosomal, 16S/drug effects , Trace Elements/blood , Zinc/blood
15.
Toxins (Basel) ; 12(10)2020 10 08.
Article in English | MEDLINE | ID: mdl-33049917

ABSTRACT

Cry proteins produced by Bacillus thuringiensis are pore-forming toxins that disrupt the membrane integrity of insect midgut cells. The structure of such pore is unknown, but it has been shown that domain I is responsible for oligomerization, membrane insertion and pore formation activity. Specifically, it was proposed that some N-terminal α-helices are lost, leading to conformational changes that trigger oligomerization. We designed a series of mutants to further analyze the molecular rearrangements at the N-terminal region of Cry1Ab toxin that lead to oligomer assembly. For this purpose, we introduced Cys residues at specific positions within α-helices of domain I for their specific labeling with extrinsic fluorophores to perform Föster resonance energy transfer analysis to fluorescent labeled Lys residues located in Domains II-III, or for disulfide bridges formation to restrict mobility of conformational changes. Our data support that helix α-1 of domain I is cleaved out and swings away from the toxin core upon binding with Manduca sexta brush border membrane vesicles. That movement of helix α-2b is also required for the conformational changes involved in oligomerization. These observations are consistent with a model proposing that helices α-2b and α-3 form an extended helix α-3 necessary for oligomer assembly of Cry toxins.


Subject(s)
Bacillus cereus/metabolism , Bacillus thuringiensis Toxins/pharmacology , Endotoxins/pharmacology , Hemolysin Proteins/pharmacology , Manduca/drug effects , Pest Control, Biological , Animals , Bacillus cereus/genetics , Bacillus thuringiensis Toxins/chemistry , Bacillus thuringiensis Toxins/genetics , Bacillus thuringiensis Toxins/metabolism , Endotoxins/chemistry , Endotoxins/genetics , Endotoxins/metabolism , Hemolysin Proteins/chemistry , Hemolysin Proteins/genetics , Hemolysin Proteins/metabolism , Manduca/metabolism , Microvilli/drug effects , Microvilli/metabolism , Mutation , Protein Conformation, alpha-Helical , Protein Multimerization , Structure-Activity Relationship
16.
Nutrients ; 12(10)2020 Oct 06.
Article in English | MEDLINE | ID: mdl-33036197

ABSTRACT

In age-related macular degeneration (AMD), both systemic and local zinc levels decline. Elevation of zinc in clinical studies delayed the progression to end-stage AMD. However, the molecular pathways underpinning this beneficial effect are not yet identified. In this study, we used differentiated primary human fetal retinal pigment epithelium (RPE) cultures and long-term zinc supplementation to carry out a combined transcriptome, proteome and secretome analysis from three genetically different human donors. After combining significant differences, we identified the complex molecular networks using Database for Annotation, Visualization and Integrated Discovery (DAVID) and Ingenuity Pathway Analysis (IPA). The cell cultures from the three donors showed extensive pigmentation, development of microvilli and basal infoldings and responded to zinc supplementation with an increase in transepithelial electrical resistance (TEER) (apical supplementation: 443.2 ± 79.3%, basal supplementation: 424.9 ± 116.8%, compared to control: 317.5 ± 98.2%). Significant changes were observed in the expression of 1044 genes, 151 cellular proteins and 124 secreted proteins. Gene set enrichment analysis revealed changes in specific molecular pathways related to cell adhesion/polarity, extracellular matrix organization, protein processing/transport, and oxidative stress response by zinc and identified a key upstream regulator effect similar to that of TGFB1.


Subject(s)
Micronutrients , Proteome , Retinal Pigment Epithelium/cytology , Retinal Pigment Epithelium/metabolism , Signal Transduction/drug effects , Signal Transduction/genetics , Transcriptome , Transforming Growth Factor beta1/physiology , Zinc/pharmacology , Cell Adhesion/drug effects , Cell Adhesion/genetics , Cell Polarity/drug effects , Cell Polarity/genetics , Cells, Cultured , Electric Impedance , Extracellular Matrix/metabolism , Humans , Macular Degeneration/genetics , Macular Degeneration/metabolism , Macular Degeneration/prevention & control , Microvilli/drug effects , Oxidative Stress/drug effects , Oxidative Stress/genetics , Pigmentation/drug effects , Protein Transport/drug effects , Retinal Pigment Epithelium/embryology , Retinal Pigment Epithelium/physiology , Zinc/metabolism
17.
Nanotoxicology ; 14(10): 1301-1323, 2020 12.
Article in English | MEDLINE | ID: mdl-32930049

ABSTRACT

Food grade titanium dioxide (TiO2) containing nanofractions, is commonly applied to whiten and brighten food products, which put consumers under health risks of ingesting TiO2 nanoparticles (NPs). Although the oral toxicity of TiO2-NPs has been evaluated in several studies, gaps in knowledge exist regarding interactions between NPs and food components. Therefore, this study aimed to estimate the influence of TiO2-NPs on nutrient absorption and metabolism through an in situ intestinal loop experiment which conducted on adult Sprague Dawley (SD) rats after 30-d gastrointestinal exposure to TiO2-NPs of two different sizes (N-TiO2 and M-TiO2). Results showed that exposure to TiO2-NPs caused flat apical membranes with sparse and short microvilli and inflammatory infiltration in small intestine. Both particles were absorbed into small intestinal cells, but N-TiO2 with smaller size could more easily be transported through gut and raise the blood titanium (Ti) levels. Changes in serum levels of amino acid were also different after exposure to these two particles. After injecting mixed solution of nutrients into in situ intestinal loop, the N-TiO2 exposure groups displayed significant absorption inhibition of the added histidine (His) and metabolism disorder of some non-added amino acid. However, no influence was observed on metal elements or glucose levels. This study identified TiO2-NPs with small sizes could affect nutrient absorption and metabolism by inducing intestinal epithelium injury, and amino acids were more susceptible than metal elements and glucose. These findings suggested that foods supplemented with TiO2-NPs should be carefully consumed by people with high protein requirements, such as children, the elderly, and patients with high metabolic disease or intestinal inflammation.


Subject(s)
Amino Acids/metabolism , Glucose/metabolism , Intestinal Absorption/drug effects , Nanoparticles/toxicity , Nutrients/metabolism , Titanium/toxicity , Administration, Oral , Aged , Animals , Humans , Inflammation , Intestinal Mucosa/drug effects , Intestinal Mucosa/metabolism , Intestine, Small/drug effects , Intestine, Small/metabolism , Microvilli/drug effects , Microvilli/metabolism , Rats , Rats, Sprague-Dawley
18.
Nutrients ; 12(9)2020 Aug 24.
Article in English | MEDLINE | ID: mdl-32847024

ABSTRACT

The inclusion of pulses in traditional wheat-based food products is increasing as the food industry and consumers are recognizing the nutritional benefits due to the high protein, antioxidant activity, and good source of dietary fiber of pulses. Iron deficiency is a significant global health challenge, affecting approximately 30% of the world's population. Dietary iron deficiency is the foremost cause of anemia, a condition that harms cognitive development and increases maternal and infant mortality. This study intended to demonstrate the potential efficacy of low-phytate biofortified pea varieties on dietary iron (Fe) bioavailability, as well as on intestinal microbiome, energetic status, and brush border membrane (BBM) functionality in vivo (Gallus gallus). We hypothesized that the low-phytate biofortified peas would significantly improve Fe bioavailability, BBM functionality, and the prevalence of beneficial bacterial populations. A six-week efficacy feeding (n = 12) was conducted to compare four low-phytate biofortified pea diets with control pea diet (CDC Bronco), as well as a no-pea diet. During the feeding trial, hemoglobin (Hb), body-Hb Fe, feed intake, and body weight were monitored. Upon the completion of the study, hepatic Fe and ferritin, pectoral glycogen, duodenal gene expression, and cecum bacterial population analyses were conducted. The results indicated that certain low-phytate pea varieties provided greater Fe bioavailability and moderately improved Fe status, while they also had significant effects on gut microbiota and duodenal brush border membrane functionality. Our findings provide further evidence that the low-phytate pea varieties appear to improve Fe physiological status and gut microbiota in vivo, and they highlight the likelihood that this strategy can further improve the efficacy and safety of the crop biofortification and mineral bioavailability approach.


Subject(s)
Animal Feed , Gastrointestinal Microbiome/drug effects , Iron/blood , Microvilli/drug effects , Phytic Acid/pharmacology , Pisum sativum/metabolism , Animals , Chickens , Phytic Acid/metabolism
19.
Life Sci ; 258: 118085, 2020 Oct 01.
Article in English | MEDLINE | ID: mdl-32663578

ABSTRACT

BACKGROUND: An integral intestinal barrier is essential for intestinal homeostasis. Yet, as a side effect of cancer treatment, chemotherapeutic drugs have been reported to cause mucositis. In a recent study, we found that alginate oligosaccharides (AOS) prevent busulfan induced intestinal mucositis. However, it is not known if AOS improves small intestine epithelial cell integrity and migration, which are two essential processes for maintaining the mechanical barrier function of the small intestine. In the current investigation, we aimed to explore the effects of AOS on the integrity and migration of small intestine cells using swine intestinal epithelial IPEC-J2 cells. METHODS: Cell integrity was determined using the TEER assay. Cell migration capability was detected using a wound healing experiment. Small interfering RNA (siRNA) was used to inhibit mannose receptor (MR) expression. Western blotting and immunofluorescence staining were used to determine protein expression. RESULTS: Increasing levels of AOS improved cell integrity as measure by TEER. At the same time, AOS improved IPEC-J2 cell migration capacity as shown in the wound closure assay. It is interesting to note that AOS increased the expression of intestinal microvillus proteins and junction proteins to benefit cell integrity. MR siRNA blocked the action of AOS on cell integrity and cell migration and inhibited the expression of microvillus and cell junction proteins. CONCLUSION: We identified the underlying mechanisms by which AOS improved small intestinal mucositis. As a novel, natural food additive, AOS may be administered to prevent intestinal mucositis induced by chemotherapy or other issues.


Subject(s)
Alginates/pharmacology , Cell Movement/drug effects , Intestine, Small/cytology , Oligosaccharides/pharmacology , Animals , Cell Line , Lectins, C-Type/metabolism , Mannose Receptor , Mannose-Binding Lectins/metabolism , Microfilament Proteins/metabolism , Microvilli/drug effects , Microvilli/metabolism , Myosins/metabolism , RNA, Small Interfering/metabolism , Receptors, Cell Surface/metabolism , Swine , Tight Junction Proteins/metabolism , Wound Healing/drug effects
20.
Sci Rep ; 10(1): 10877, 2020 07 02.
Article in English | MEDLINE | ID: mdl-32616784

ABSTRACT

Epithelial ovarian cancer (EOC) metastasis occurs by exfoliation of cells and multicellular aggregates (MCAs) from the tumor into the peritoneal cavity, adhesion to and retraction of peritoneal mesothelial cells and subsequent anchoring. Elevated levels of lysophosphatidic acid (LPA) have been linked to aberrant cell proliferation, oncogenesis, and metastasis. LPA disrupts junctional integrity and epithelial cohesion in vitro however, the fate of free-floating cells/MCAs and the response of host peritoneal tissues to LPA remain unclear. EOC MCAs displayed significant LPA-induced changes in surface ultrastructure with the loss of cell surface protrusions and poor aggregation, resulting in increased dissemination of small clusters compared to untreated control MCAs. LPA also diminished the adhesive capacity of EOC single cells and MCAs to murine peritoneal explants and impaired MCA survival and mesothelial clearance competence. Peritoneal tissues from healthy mice injected with LPA exhibited enhanced mesothelial surface microvilli. Ultrastructural alterations were associated with restricted peritoneal susceptibility to metastatic colonization by single cells as well as epithelial-type MCAs. The functional consequence is an LPA-induced dissemination of small mesenchymal-type clusters, promoting a miliary mode of peritoneal seeding that complicates surgical removal and is associated with worse prognosis.


Subject(s)
Carcinoma, Ovarian Epithelial/pathology , Cell Aggregation/drug effects , Epithelial Cells/drug effects , Lysophospholipids/pharmacology , Ovarian Neoplasms/pathology , Animals , Carcinoma, Ovarian Epithelial/secondary , Cell Adhesion/drug effects , Cell Line, Tumor , Female , Humans , Mice , Mice, Inbred C57BL , Microscopy, Electron, Scanning , Microvilli/drug effects , Peritoneal Neoplasms/secondary , Tumor Microenvironment
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