scholarly journals Engineered E. coli Nissle 1917 for the delivery of matrix-tethered therapeutic domains to the gut

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Pichet Praveschotinunt ◽  
Anna M. Duraj-Thatte ◽  
Ilia Gelfat ◽  
Franziska Bahl ◽  
David B. Chou ◽  
...  
Keyword(s):  
Critical Role ◽  
Intestinal Barrier ◽  
Mucosal Healing ◽  
Intestinal Barrier Function ◽  
Protective Effects ◽  
Genetically Engineer ◽  
Protein Matrices

AbstractMucosal healing plays a critical role in combatting the effects of inflammatory bowel disease, fistulae and ulcers. While most treatments for such diseases focus on systemically delivered anti-inflammatory drugs, often leading to detrimental side effects, mucosal healing agents that target the gut epithelium are underexplored. We genetically engineer Escherichia coli Nissle 1917 (EcN) to create fibrous matrices that promote gut epithelial integrity in situ. These matrices consist of curli nanofibers displaying trefoil factors (TFFs), known to promote intestinal barrier function and epithelial restitution. We confirm that engineered EcN can secrete the curli-fused TFFs in vitro and in vivo, and is non-pathogenic. We observe enhanced protective effects of engineered EcN against dextran sodium sulfate-induced colitis in mice, associated with mucosal healing and immunomodulation. This work lays a foundation for the development of a platform in which the in situ production of therapeutic protein matrices from beneficial bacteria can be exploited.

scholarly journals Probiotic Associated Therapeutic Curli Hybrids (PATCH)

2018 ◽  
Author(s):  
Pichet Praveschotinunt ◽  
Anna M. Duraj-Thatte ◽  
Ilia Gelfat ◽  
Franziska Bahl ◽  
David B. Chou ◽  
...  
Keyword(s):  
Barrier Function ◽  
Unmet Need ◽  
Intestinal Barrier ◽  
Genetically Engineered ◽  
Intestinal Barrier Function ◽  
Beneficial Bacteria ◽  
Fibrous Matrix

AbstractThere is an unmet need for new treatment methods for inflammatory bowel disease (IBD) that can reliably maintain remission without leading to detrimental side effects. Beneficial bacteria have been utilized as an alternative treatment for IBD albeit with low efficacy. We genetically engineered Escherichia coli Nissle 1917 (EcN) to create an anti-inflammatory fibrous matrix in situ. This matrix consists of EcN-produced curli nanofibers displaying trefoil factors (TFFs), known to promote intestinal barrier function and epithelial restitution. We confirmed that engineered EcN was able to secrete the curli-fused TFFs in vitro and in vivo, and was non-pathogenic. We observed an enhanced protective effect of engineered EcN against dextran sodium sulfate induced colitis in mice, associated with barrier function reinforcement and immunomodulation. This work sets the foundation for the development of a novel therapeutic platform in which the in situ production of a therapeutic protein matrix from beneficial bacteria can be exploited.

Regulation of human epithelial tight junction proteins by Lactobacillus plantarum in vivo and protective effects on the epithelial barrier

2010 ◽  
Vol 298 (6) ◽  
pp. G851-G859 ◽  
Author(s):  
Jurgen Karczewski ◽  
Freddy J. Troost ◽  
Irene Konings ◽  
Jan Dekker ◽  
Michiel Kleerebezem ◽  
...  
Keyword(s):  
Tight Junction ◽  
Lactobacillus Plantarum ◽  
Transmembrane Protein ◽  
Intestinal Barrier ◽  
Protective Effects ◽  
Epithelial Tight Junction ◽  
Vitro Model ◽  
Probiotic Mechanisms

Lactobacillus plantarum , a commensal bacterium of humans, has been proposed to enhance the intestinal barrier, which is compromised in a number of intestinal disorders. To study the effect of L. plantarum strain WCFS1 on human barrier function, healthy subjects were administered L. plantarum or placebo in the duodenum for 6 h by means of a feeding catheter. The scaffold protein zonula occludens (ZO)-1 and transmembrane protein occludin were found to be significantly increased in the vicinity of the tight-junction (TJ) structures, which form the paracellular seal between cells of the epithelium. In an in vitro model of the human epithelium, L. plantarum induced translocation of ZO-1 to the TJ region; however, the effects on occludin were minor compared with those seen in vivo. L. plantarum was shown to activate Toll-like receptor 2 (TLR2) signaling, and treatment of Caco-2 monolayers with the TLR2 agonist Pam3-Cys-SK4(PCSK) significantly increased fluorescent staining of occludin in the TJ. Pretreatment of Caco-2 monolayers with L. plantarum or PCSK significantly attenuated the effects of phorbol ester-induced dislocation of ZO-1 and occludin and the associated increase in epithelial permeability. Our results identifying commensal bacterial stimulation of TLR2 in the gut epithelium as a regulator of epithelial integrity have important implications for understanding probiotic mechanisms and the control of intestinal homeostasis.

Polyphenols: Anti-Platelet Nutraceutical?

2018 ◽  
Vol 24 (2) ◽  
pp. 146-157 ◽  
Author(s):  
Valeria Ludovici ◽  
Jens Barthelmes ◽  
Matthias P. Nagele ◽  
Andreas J. Flammer ◽  
Isabella Sudano
Keyword(s):  
Platelet Aggregation ◽  
Platelet Activation ◽  
Therapeutic Potential ◽  
Critical Role ◽  
Organ Damage ◽  
Low Grade ◽  
Protective Effects ◽  
Dietary Polyphenols

Background: Coronary artery disease (CAD) is a disease progressing over many years. Genetic factors, as well as the exposure to risk factors, are continuously leading to endothelial dysfunction, vascular alterations and, eventually, organ damage, major cardiovascular events and deaths. Oxidative stress, platelet hyperactivity and low-grade inflammation are important modulators in this context, contributing to plaque formation. Since platelet activation plays a critical role in the development and progression of atherothrombotic events, the inhibition of platelet hyperactivity may contribute to decreased atherothrombotic risk. The consumption of bioactive foods, and plant-derived polyphenols in particular, might impart anti-thrombotic and cardiovascular protective effects. Methods: Aim of this work is to focus on the potential of dietary derived polyphenols to reduce platelet hyperactivity or hypercoagulability in addition to discussing their possible complementary anti-platelet therapeutic potential. All the relevant publications on this topic were systematically reviewed. Results: Various studies demonstrated that polyphenol supplementation affects platelet aggregation and function in vitro and in vivo, mainly neutralizing free radicals, inhibiting platelet activation and related signal transduction pathways, blocking thromboxane A2 receptors and enhancing nitric oxide production. Experimental data concerning the effect of dietary polyphenols on platelet aggregation in vivo are poor, and results are often conflicting. Only flavanols clearly mirrored in vivo showed the efficacy in vitro in modulating platelet function. Conclusion: Dietary polyphenols, and above all flavanols contained in cocoa and berries, reduce platelet activation and aggregation via multiple pathways. However, more controlled interventional studies are required to establish which doses are required as well as what circulating concentrations are sufficient to induce functional antiplatelet effects.

scholarly journals Designation of a Novel DKK1 Multiepitope DNA Vaccine and Inhibition of Bone Loss in Collagen-Induced Arthritic Mice

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaoqing Zhang ◽  
Sibo Liu ◽  
Shentao Li ◽  
Yuxuan Du ◽  
Yunpeng Dou ◽  
...  
Keyword(s):  
Bone Loss ◽  
Dna Vaccine ◽  
Bone Erosion ◽  
Critical Role ◽  
Serum Levels ◽  
Positive Control ◽  
Protective Effects ◽  
High Level

Dickkopf-1 (DKK1), a secretory inhibitor of canonical Wnt signaling, plays a critical role in certain bone loss diseases. Studies have shown that serum levels of DKK1 are significantly higher in rheumatoid arthritis (RA) patients and are correlated with the severity of the disease, which indicates the possibility that bone erosion in RA may be inhibited by neutralizing the biological activity of DKK1. In this study, we selected a panel of twelve peptides using the software DNASTAR 7.1 and screened high affinity and immunogenicity epitopesin vitroandin vivoassays. Furthermore, we optimized four B cell epitopes to design a novel DKK1 multiepitope DNA vaccine and evaluated its bone protective effects in collagen-induced arthritis (CIA), a mouse model of RA. High level expression of the designed vaccine was measured in supernatant of COS7 cells. In addition, intramuscular immunization of BALB/c mice with this vaccine was also highly expressed and sufficient to induce the production of long-term IgG, which neutralized natural DKK1in vivo. Importantly, this vaccine significantly attenuated bone erosion in CIA mice compared with positive control mice. These results provide evidence for the development of a DNA vaccine targeted against DKK1 to attenuate bone erosion.

scholarly journals Aflatoxin B1 and Aflatoxin M1 Induce Compromised Intestinal Integrity through Clathrin-Mediated Endocytosis

Toxins ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 184
Author(s):  
Yanan Gao ◽  
Xiaoyu Bao ◽  
Lu Meng ◽  
Huimin Liu ◽  
Jiaqi Wang ◽  
...  
Keyword(s):  
Aflatoxin B1 ◽  
Intestinal Barrier ◽  
Fluorescein Isothiocyanate ◽  
Intestinal Barrier Function ◽  
Aflatoxin M1 ◽  
Dependent Manner ◽  
Simultaneous Exposure ◽  
Intestinal Integrity

With the growing diversity and complexity of diet, humans are at risk of simultaneous exposure to aflatoxin B1 (AFB1) and aflatoxin M1 (AFM1), which are well-known contaminants in dairy and other agricultural products worldwide. The intestine represents the first barrier against external contaminants; however, evidence about the combined effect of AFB1 and AFM1 on intestinal integrity is lacking. In vivo, the serum biochemical parameters related to intestinal barrier function, ratio of villus height/crypt depth, and distribution pattern of claudin-1 and zonula occluden-1 were significantly affected in mice exposed to 0.3 mg/kg b.w. AFB1 and 3.0 mg/kg b.w. AFM1. In vitro results on differentiated Caco-2 cells showed that individual and combined AFB1 (0.5 and 4 μg/mL) and AFM1 (0.5 and 4 μg/mL) decreased cell viability and trans-epithelial electrical resistance values as well as increased paracellular permeability of fluorescein isothiocyanate-dextran in a dose-dependent manner. Furthermore, AFM1 aggravated AFB1-induced compromised intestinal barrier, as demonstrated by the down-regulation of tight junction proteins and their redistribution, particularly internalization. Adding the inhibitor chlorpromazine illustrated that clathrin-mediated endocytosis partially contributed to the compromised intestinal integrity. Synergistic and additive effects were the predominant interactions, suggesting that these toxins are likely to have negative effects on human health.

scholarly journals Pure Total Flavonoids From Citrus Protect Against Nonsteroidal Anti-inflammatory Drug-Induced Small Intestine Injury by Promoting Autophagy in vivo and in vitro

2021 ◽  
Vol 12 ◽  
Author(s):  
Shanshan Chen ◽  
Jianping Jiang ◽  
Guanqun Chao ◽  
Xiaojie Hong ◽  
Haijun Cao ◽  
...  
Keyword(s):  
Small Intestine ◽  
Western Blotting ◽  
Intestinal Barrier ◽  
Total Flavonoids ◽  
Protective Effects ◽  
Drug Induced ◽  
Expression Levels ◽  
Anti Inflammatory

Small intestine injury is an adverse effect of non-steroidal anti-inflammatory drugs (NSAIDs) that urgently needs to be addressed for their safe application. Although pure total flavonoids from citrus (PTFC) have been marketed for the treatment of digestive diseases, their effects on small intestine injury and the underlying mechanism of action remain unknown. This study aimed to investigate the potential role of autophagy in the mechanism of NSAID (diclofenac)-induced intestinal injury in vivo and in vitro and to demonstrate the protective effects of PTFC against NSAID-induced small intestine disease. The results of qRT-PCR, western blotting, and immunohistochemistry showed that the expression levels of autophagy-related 5 (Atg5), light chain 3 (LC3)-II, and tight junction (TJ) proteins ZO-1, claudin-1, and occludin were decreased in rats with NSAID-induced small intestine injury and diclofenac-treated IEC-6 cells compared with the control groups. In the PTFC group, Atg5 and LC3-II expression, TJ protein expression, and the LC3-II/LC3-I ratio increased. Furthermore, the mechanism by which PTFC promotes autophagy in vivo and in vitro was evaluated by western blotting. Expression levels of p-PI3K and p-Akt increased in the intestine disease-induced rat model group compared with the control, but decreased in the PTFC group. Autophagy of IEC-6 cells was upregulated after treatment with a PI3K inhibitor, and the upregulation was significantly more after PTFC treatment, suggesting PTFC promoted autophagy through the PI3K/Akt signaling pathway. In conclusion, PTFC protected intestinal barrier integrity by promoting autophagy, which demonstrates its potential as a therapeutic candidate for NSAID-induced small intestine injury.

scholarly journals A Novel Role of A2AR in the Maintenance of Intestinal Barrier Function of Eteric Glia from Hypoxia-Induced Injury by Combining with mGluR5

2021 ◽  
Vol 12 ◽  
Author(s):  
Lihua Sun ◽  
Xiang Li ◽  
Haidi Guan ◽  
Shuaishuai Chen ◽  
Xin Fan ◽  
...  
Keyword(s):  
Metabotropic Glutamate Receptor ◽  
Ischemia Reperfusion ◽  
Intestinal Barrier ◽  
Intestinal Barrier Function ◽  
Metabotropic Glutamate ◽  
Enteric Glial Cells ◽  
Intestinal Ischemia Reperfusion

During acute intestinal ischemia reperfusion (IR) injury, the intestinal epithelial barrier (IEB) function is often disrupted. Enteric glial cells (EGCs) play an important role in maintaining the integrity of IEB functions. However, how EGCs regulate IEB function under IR stimulation is unknown. The present study reveals that the adenosine A2A receptor (A2AR) is important for mediating the barrier-modulating roles of EGCs. A2AR knockout (KO) experiments revealed more serious intestinal injury in A2AR KO mice than in WT mice after IR stimulation. Moreover, A2AR expression was significantly increased in WT mice when challenged by IR. To further investigate the role of A2AR in IEB, we established an in vitro EGC-Caco-2 co-culture system. Hypoxia stimulation was used to mimic the process of in vivo IR. Treating EGCs with the CGS21680 A2AR agonist attenuated hypoxia-induced intestinal epithelium damage through up-regulating ZO-1 and occludin expression in cocultured Caco-2 monolayers. Furthermore, we showed that A2AR and metabotropic glutamate receptor 5 (mGluR5) combine to activate the PKCα-dependent pathway in conditions of hypoxia. This study shows, for the first time, that hypoxia induces A2AR-mGluR5 interaction in EGCs to protect IEB function via the PKCα pathway.

scholarly journals Duodenum Intestine-Chip for preclinical drug assessment in a human relevant model

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Magdalena Kasendra ◽  
Raymond Luc ◽  
Jianyi Yin ◽  
Dimitris V Manatakis ◽  
Gauri Kulkarni ◽  
...  
Keyword(s):  
Drug Transport ◽  
Intestinal Barrier ◽  
New Drugs ◽  
Intestinal Barrier Function ◽  
Human Pharmacokinetics ◽  
Relevant Model ◽  
Cell Subpopulations ◽  
And Function

Induction of intestinal drug metabolizing enzymes can complicate the development of new drugs, owing to the potential to cause drug-drug interactions (DDIs) leading to changes in pharmacokinetics, safety and efficacy. The development of a human-relevant model of the adult intestine that accurately predicts CYP450 induction could help address this challenge as species differences preclude extrapolation from animals. Here, we combined organoids and Organs-on-Chips technology to create a human Duodenum Intestine-Chip that emulates intestinal tissue architecture and functions, that are relevant for the study of drug transport, metabolism, and DDI. Duodenum Intestine-Chip demonstrates the polarized cell architecture, intestinal barrier function, presence of specialized cell subpopulations, and in vivo relevant expression, localization, and function of major intestinal drug transporters. Notably, in comparison to Caco-2, it displays improved CYP3A4 expression and induction capability. This model could enable improved in vitro to in vivo extrapolation for better predictions of human pharmacokinetics and risk of DDIs.

Abstract 448: Etv2-Mir130a-Jarid2 Cascade Regulates Vascular Patterning During Embryogenesis

2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Bhairab N Singh ◽  
Naoyuki Tahara ◽  
Yasuhiko Kawakami ◽  
Naoko Koyano-Nakagawa ◽  
Wuming Gong ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Critical Role ◽  
Yolk Sac ◽  
Zebrafish Embryos ◽  
Vascular Patterning ◽  
Downstream Target

Remodeling of the pre-existing primitive vasculature is necessary for the formation of a complex branched vascular architecture. However, the factors that modulate these processes are incompletely defined. Previously, we defined the role of microRNAs (miRNAs) in endothelial specification. In the present study, we further examined the Etv2-Cre mediated ablation of Dicer L/L and characterized the perturbed vascular patterning in the embryo proper and yolk-sac. We mechanistically defined an important role for miR-130a , an Etv2 downstream target, in the mediation of vascular patterning and angiogenesis in vitro and in vivo . Inducible overexpression of miR-130a resulted in robust induction of vascular sprouts and angiogenesis with increased uptake of acetylated-LDL. Mechanistically, miR-130a directly regulates Jarid2 expression by binding to its 3’-UTR region. CRISPR/Cas9 mediated knockout of miR-130a showed increased levels of Jarid2 in the ES/EB system. Further, the levels of Jarid2 transcripts were increased in the Etv2-null embryos at E8.5. In the in vivo settings, injection of miR-130a specific morpholinos in zebrafish embryos resulted in perturbed vascular patterning with reduced levels of endothelial transcripts in the miR-130a morphants. qPCR and in situ hybridization techniques demonstrated increased expression of jarid2a in the miR-130a morphants in vivo . These findings demonstrate a critical role for Etv2-miR-130a-Jarid2 in vascular patterning both in vitro and in vivo .

scholarly journals CX3CR1+ mononuclear phagocytes support colitis-associated innate lymphoid cell production of IL-22

2014 ◽  
Vol 211 (8) ◽  
pp. 1571-1583 ◽  
Author(s):  
Randy S. Longman ◽  
Gretchen E. Diehl ◽  
Daniel A. Victorio ◽  
Jun R. Huh ◽  
Carolina Galan ◽  
...  
Keyword(s):  
Critical Role ◽  
Mucosal Healing ◽  
Mononuclear Phagocytes ◽  
Lymphoid Cells ◽  
Spatial Proximity ◽  
Gm Csf ◽  
Close Spatial Proximity ◽  
Myd88 Signaling

Interleukin (IL)-22–producing group 3 innate lymphoid cells (ILC3) promote mucosal healing and maintain barrier integrity, but how microbial signals are integrated to regulate mucosal protection offered by these cells remains unclear. Here, we show that in vivo depletion of CX3CR1+ mononuclear phagocytes (MNPs) resulted in more severe colitis and death after infection with Citrobacter rodentium. This phenotype was rescued by exogenous IL-22, which was endogenously produced by ILC3 in close spatial proximity to CX3CR1+ MNPs that were dependent on MyD88 signaling. CX3CR1+ MNPs from both mouse and human tissue produced more IL-23 and IL-1β than conventional CD103+ dendritic cells (cDCs) and were more efficient than cDCs in supporting IL-22 production in ILC3 in vitro and in vivo. Further, colonic ILC3 from patients with mild to moderate ulcerative colitis or Crohn’s disease had increased IL-22 production. IBD-associated SNP gene set analysis revealed enrichment for genes selectively expressed in human intestinal MNPs. The product of one of these, TL1A, potently enhanced IL-23– and IL-1β-induced production of IL-22 and GM-CSF by ILC3. Collectively, these results reveal a critical role for CX3CR1+ mononuclear phagocytes in integrating microbial signals to regulate colonic ILC3 function in IBD.

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