Anti-adhesive Molecules Research Articles

Modulation of the allosteric and vasoregulatory arms of erythrocytic oxygen transport.

Efficient distribution of oxygen (O2) to the tissues in mammals depends on the evolved ability of red blood cell (RBC) hemoglobin (Hb) to sense not only O2 levels, but metabolic cues such as pH, PCO2, and organic phosphates, and then dispense or take up oxygen accordingly. O2 delivery is the product of not only oxygen release from RBCs, but also blood flow, which itself is also governed by vasoactive molecular mediators exported by RBCs. These vascular signals, including ATP and S-nitrosothiols (SNOs) are produced and exported as a function of the oxygen and metabolic milieu, and then fine-tune peripheral metabolism through context-sensitive vasoregulation. Emerging and repurposed RBC-oriented therapeutics can modulate either or both of these allosteric and vasoregulatory activities, with a single molecule or other intervention influencing both arms of O2 transport in some cases. For example, organic phosphate repletion of stored RBCs boosts the negative allosteric effector 2,3 biphosphoglycerate (BPG) as well as the anti-adhesive molecule ATP. In sickle cell disease, aromatic aldehydes such as voxelotor can disfavor sickling by increasing O2 affinity, and in newer generations, these molecules have been coupled to vasoactive nitric oxide (NO)-releasing adducts. Activation of RBC pyruvate kinase also promotes a left shift in oxygen binding by consuming and lowering BPG, while increasing the ATP available for cell health and export on demand. Further translational and clinical investigation of these novel allosteric and/or vasoregulatory approaches to modulating O2 transport are expected to yield new insights and improve the ability to correct or compensate for anemia and other O2 delivery deficits.

MUC1 regulation in the left and right uterine horns and conceptus trophectoderm during the peri-implantation period of dromedary camel

Pregnancy maintenance in dromedary camels poses significant challenges, including early embryonic loss in the left uterine horn (LH) and unsuccessful pregnancy in the right uterine horn (RH), suggesting a potential asynchrony between conceptus signaling and uterine receptivity. The transition of the uterine epithelium from a pre-receptive to a receptive state requires a delicate balance of adhesion-promoting and anti-adhesion molecules. Mucin-1 (MUC1) acts as an anti-adhesive molecule on the uterine luminal (LE) and glandular (GE) epithelium. Downregulation of MUC1 is believed to be crucial for successful embryo attachment in various mammals. This study aimed to investigate the temporospatial expression of MUC1 in the LH and RH on Days 8, 10, and 12 pregnant dromedaries and their conceptuses. Quantitative real-time polymerase chain reaction (qrt-PCR), Western blot analysis, immunohistochemistry, and immunofluorescence techniques were employed to assess MUC1 expression at the mRNA and protein levels. The results demonstrated a reduction in MUC1 mRNA expression on Day 8, then increased on Day 10, followed by a decrease on Day 12 in LH. While the RH exhibited progressive increases, peaking on Day 12. However, MUC1 expression constantly exhibited higher levels in RH than in LH in all days. Two bands were detected at 150-kDa and 180-kDa, with the highest intensity observed on Day 10. Spatially, MUC1 was localized in the apical, cytoplasmic, and lumen of uterine glands only. MUC1 was barely detectable on Day 8 but gradually increased on Days 10 and 12 in both horns. Likewise, the RH exhibited higher MUC1 signals than the LH on Days 10 and 12. In the conceptuses, MUC1 mRNA increased on Day 8, peaked on Day 10, and declined on Day 12. Notably, MUC1 protein was detected in both the trophectoderm and endoderm, with high expression observed on Day 10 and reduced by Day 12. In conclusion, the decrease in MUC1 expression on Day 8 in the LH may be associated with maternal recognition of pregnancy (MRP), and the increase on Day 10 may related to embryo protection and movement, while the subsequent decrease on Day 12 could be linked to the embryo attachment and preparation for the implantation. Conversely, the increase of MUC1 in the RH implies a role in the anti-adhesion mechanism. These findings contribute to understanding MUC1's involvement in reproductive processes and provide insights into the complex mechanisms underlying successful pregnancy establishment and maintenance in dromedary camels.

Mucin1 utterance in oral squamous cell carcinoma: A cancer maker and target for nanotheranostics

Mucins are cell bound high molecular weight glycoproteins which are secreted by epithelial cells. Total 21 mucin variants are identified till date. Mucin1 (MUC1) is a transmembrane glycoprotein, which when reacts with beta-catenin, can able to enter the nucleus to activate T-cell factor/leukocyte enhancing factor 1 transcription factors and gene expression, after which it may inhibit cell-cell and cell-stroma interactions and function as a signal transducer, leading to tumor progression.To compare and correlate the expression and positive intensity of MUC1 in oral squamous cell carcinoma, oral epithelial dysplasia and normal oral mucosa using Immunohistochemistry. This study included a total of 45 cases in which the study groups are oral squamous cell carcinoma (n=15), oral epithelial dysplasia (n=15) and control of normal oral mucosa (n=15), which are analysed for the expression of anti MUC1 rabbit monoclonal antibody using immunohistochemical technique.The mucin1 positive cells in the study groups were as follows, 53.3% cases in OSCC, 13.3% cases in OED and none showed positivity in normal oral mucosa. The results obtained were statistically analysed using Kruskal-Wallis test and there was a statistically significant difference in score between the different tissue groups, Kruskal – Wallis H score = 13.034, p = 0.001.There is progressive increase in the MUC1 expression from oral epithelial dysplasia to OSCC. This utterance might be due to suppression of inhibitory proteins for MUC1 immunoexpression in mature atypical squamous cells as well as proposed to act both as an anti-adhesive and adhesive molecule.

Multiomics approaches to uncover endometrial receptivity in embryo implantation: A mini-review

Successful implantation requires concerted interactions during the apposition, adhesion, and invasion of the embryo into a receptive endometrium. However, the embryo implantation rate for assisted reproduction remains low despite the transfer of good quality embryos. Changes in endometrial transcriptomics, proteomics, lipidomics, and even microbiota all play important roles in embryo implantation. Specifically, the expression of steroid hormone-regulated adhesive and anti-adhesive molecules during the embryo implantation window is becoming an area of increasingly intense research. This review a) summarizes the different molecules expressed in the receptive endometrium and b) proposes the use of surface protein markers to predict pregnancy outcomes from assisted reproduction.

Surface proteins of Shiga toxin-producing Escherichia coli mediate association with milk fat globules in raw milk.

By adhering to host cells and colonizing tissues, bacterial pathogens can successfully establish infection. Adhesion is considered the first step of the infection process and bacterial adhesion to anti-adhesive compounds is now seen as a promising strategy to prevent infectious diseases. Among the natural sources of anti-adhesive molecules, the membrane of milk fat globules (MFGs) is of interest because of its compositional diversity of proteins and glycoconjugates. However, few studies have focused on the bacterial molecules involved in MFG- mediated inhibition of bacterial adhesion to enterocytes. We used three pathogenic Shiga toxin-producing Escherichia coli (STEC) strains (O26:H11 str. 21765, O157:H7 str. EDL933, and O103:H3 str. PMK5) as models to evaluate whether STEC surface proteins are involved in the affinity of STEC for MFG membrane proteins (MFGMPs). The affinity of STEC for MFGMPs was assessed both indirectly by a natural raw milk creaming test and directly by an adhesion test. Mass spectrometry was used to identify enriched STEC proteins within the protein fraction of MFGMs. Bacterial mutants were constructed and their affinity to MFGs were measured to confirm the role of the identified proteins. We found that free STEC surface proteins inhibit the concentration of the pathogen in the MFG-enriched cream in a strain-dependent manner. Moreover, the OmpA and FliC proteins were identified within the protein fraction of MFGMs. Our results suggest that FliC protein participates in STEC adhesion to MFGMPs but other STEC molecules may also participate. For the first time, this study highlighted, the involvement of STEC surface proteins in the affinity for MFGs. The mechanism of STEC-MFG association is still not fully understood but our results confirm the existence of receptor/ligand type interactions between the bacteria and MFGs. Further studies are needed to identify and specify the molecules involved in this interaction. These studies should consider the likely involvement of several factors, including adhesion molecules, and the diversity of each STEC strain.

Fibrin(ogen) Is Constitutively Expressed by Differentiated Intestinal Epithelial Cells and Mediates Wound Healing.

Fibrinogen is a large molecule synthesized in the liver and released in the blood. Circulating levels of fibrinogen are upregulated after bleeding or clotting events and support wound healing. In the context of an injury, thrombin activation drives conversion of fibrinogen to fibrin. Fibrin deposition contains tissue damage, stops blood loss, and prevents microbial infection. In most circumstances, fibrin needs to be removed to allow the resolution of inflammation and tissue repair, whereas failure of this may lead to the development of various disorders. However, the contribution of fibrinogen to tissue inflammation and repair is likely to be context-dependent. In this study, the concept that fibrin needs to be removed to allow tissue repair and to reduce inflammation is challenged by our observations that, in the intestine, fibrinogen is constitutively produced by a subset of intestinal epithelial cells and deposited at the basement membrane as fibrin where it serves as a substrate for wound healing under physiological conditions such as epithelial shedding at the tip of the small intestinal villus and surface epithelium of the colon as well as under pathological conditions that require rapid epithelial repair. The functional integrity of the intestine is ensured by the constant renewal of its simple epithelium. Superficial denuding of the epithelial cell layer occurs regularly and is rapidly corrected by a process called restitution that can be influenced by various soluble and insoluble factors. Epithelial cell interaction with the extracellular matrix greatly influences the healing process by acting on cell morphology, adhesion, and migration. The functional contribution of a fibrin(ogen) matrix in the intestine was studied under physiological and pathological contexts. Our results (immunofluorescence, immunoelectron microscopy, and quantitative PCR) show that fibrin(ogen) is a novel component of the basement membrane associated with the differentiated epithelial cell population in both the small intestine and colon. Fibrin(ogen) alone is a weak ligand for epithelial cells and behaves as an anti-adhesive molecule in the presence of type I collagen. Furthermore, the presence of fibrin(ogen) significantly shortens the time required to achieve closure of wounded epithelial cell monolayers and co-cultures in a PI3K-dependent manner. In human specimens with Crohn’s disease, we observed a major accumulation of fibrin(ogen) throughout the tissue and at denuded sites. In mice in which fibrin formation was inhibited with dabigatran treatment, dextran sulfate sodium administration provoked a significant increase in the disease activity index and pathological features such as mucosal ulceration and crypt abscess formation. Taken together, these results suggest that fibrin(ogen) contributes to epithelial healing under both normal and pathological conditions.

Podocalyxin in Normal Tissue and Epithelial Cancer.

Simple SummaryMalignancies derived from epithelial cells account for over 90% of all human cancers. Several aspects of cancer progression such as metastasis, immune evasion, and resistance to chemotherapy are often associated with poor prognosis and unfavourable patient outcomes due to limited therapeutic options. Therefore, the discovery of new biomarkers and treatment targets is essential in improving patient prognosis. Podocalyxin, a membrane protein of the CD34 family, has recently gained recognition as a potential diagnostic and prognostic biomarker, as well as a potential target for chemoresistance. This review summarises the current knowledge of podocalyxin in normal tissues and epithelial cancers, highlighting its potential utility in cancer management.Podocalyxin (PODXL), a glycosylated cell surface sialomucin of the CD34 family, is normally expressed in kidney podocytes, vascular endothelial cells, hematopoietic progenitors, mesothelium, as well as a subset of neurons. In the kidney, PODXL functions primarily as an antiadhesive molecule in podocyte epithelial cells, regulating adhesion and cell morphology, and playing an essential role in the development and function of the organ. Outside the kidney, PODXL plays subtle roles in tissue remodelling and development. Furthermore, many cancers, especially those that originated from the epithelium, have been reported to overexpress PODXL. Collective evidence suggests that PODXL overexpression is linked to poor prognosis, more aggressive tumour progression, unfavourable treatment outcomes, and possibly chemoresistance. This review summarises our current knowledge of PODXL in normal tissue function and epithelial cancer, with a particular focus on its underlying roles in cancer metastasis, likely involvement in chemoresistance, and potential use as a diagnostic and prognostic biomarker.

On the strong connection between nanoscale adhesion of Yad fimbriae and macroscale attachment of Yad-decorated bacteria to glycosylated, hydrophobic and hydrophilic surfaces.

Yad fimbriae are currently viewed as versatile bacterial adhesins able to significantly mediate host or plant-pathogen recognition and contribute to the persistence of Escherichia coli in both the environment and within hosts. To date, however, the underlying adhesion process of Yad fimbriae on surfaces defined by controlled coating chemistries has not been evaluated on the relevant molecular scale. In this work, the interaction forces operational between Yad fimbriae expressed by genetically modified E. coli and self-assembled monolayers (SAM) differing in terms of charge, hydrophobicity or the nature of decorating sugar units are quantified by Single Molecule Force Spectroscopy (SMFS) on the nanoscale. It is found that the adhesion of Yad fimbriae onto probes functionalized with xylose is as strong as that measured with probes decorated with anti-Yad antibodies (ca. 80 to 300 pN). In contrast, the interactions of Yad with galactose, lactose, mannose, -OH, -NH2, -COOH and -CH3 terminated SAMs are clearly non-specific. Interpretation of SMFS measurements on the basis of worm-like-chain modeling for polypeptide nanomechanics further leads to the estimates of the maximal extension of Yad fimbriae upon stretching, of their persistence length and of their polydispersity. Finally, we show for the first time a strong correlation between the adhesion properties of Yad-decorated bacteria determined from conventional macroscopic counting methods and the molecular adhesion capacity of Yad fimbriae. This demonstration advocates the effort that should be made to understand on the nanoscale level the interactions between fimbriae and their cognate ligands. The results could further help the design of potential anti-adhesive molecules or surfaces to better fight against the virulence of bacterial pathogens.

Antibacterial activity of therapeutic agent-immobilized nanostructured TiCaPCON films against antibiotic-sensitive and antibiotic-resistant Escherichia coli strains

The development of flexible and low-cost methods of surface functionalization to fight infection at the early stage is an urgent scientific task. Herein, polymerization in low-pressure plasma rich in COOH species and carbodiimide chemistry methods were utilized to immobilize four different therapeutic agents (antibiotic (gentamicin), antimicrobial peptide (indolicidin), anti-adhesive molecules (heparin) and nitroxide radicals (2,2,5,5-tetramethyl-3-carboxyl-pyrrolidine-1-oxyl)) on the surface of nanostructured biocompatible TiCaPCON films to impart antibacterial characteristics. The polymers deposited from COOH-rich plasma showed decent stability in phosphate-buffered saline solution and were successfully used for the immobilization of different therapeutic agents via ionic or covalent bond. The bactericide attachment was proved by FTIR spectroscopy and XPS analysis. All samples with grafted therapeutic agents were hydrophilic with water contact angle values in the range of 26–56°. Bactericide release tests indicated the maximum concentration of therapeutic agents in the case of ionic immobilization. In case of covalent immobilization, fast initial release observed over 24 h was followed by slower leaching in the next 24 h (indolicidin), 48 h (heparin), and 96 h (gentamicin). The pH-sensitive COOH plasma polymer degradation and gentamicin release were demonstrated. The bactericide-linked films showed noticeable reduction of the antibiotic-sensitive E. coli U20 strain and, except indolicidin-immobilized samples, effectively inhibited growth of the antibiotic-resistant E. coli K261 strain at their initial concentration of 104 CFU/mL. The films with nitroxide radicals not only exhibited the highest antibacterial activity against E. coli K261 cells (100% after 8 h), but also prevented the biofilm formation.

FimH and Anti-Adhesive Therapeutics: A Disarming Strategy Against Uropathogens.

Chaperone-usher fimbrial adhesins are powerful weapons against the uropathogens that allow the establishment of urinary tract infections (UTIs). As the antibiotic therapeutic strategy has become less effective in the treatment of uropathogen-related UTIs, the anti-adhesive molecules active against fimbrial adhesins, key determinants of urovirulence, are attractive alternatives. The best-characterized bacterial adhesin is FimH, produced by uropathogenic Escherichia coli (UPEC). Hence, a number of high-affinity mono- and polyvalent mannose-based FimH antagonists, characterized by different bioavailabilities, have been reported. Given that antagonist affinities are firmly associated with the functional heterogeneities of different FimH variants, several FimH inhibitors have been developed using ligand-drug discovery strategies to generate high-affinity molecules for successful anti-adhesion therapy. As clinical trials have shown d-mannose’s efficacy in UTIs prevention, it is supposed that mannosides could be a first-in-class strategy not only for UTIs, but also to combat other Gram-negative bacterial infections. Therefore, the current review discusses valuable and effective FimH anti-adhesive molecules active against UTIs, from design and synthesis to in vitro and in vivo evaluations.

Role of routine hysteroscopy in previous failed ICSI: a continuous clinical dilemma

BackgroundThe benefit of hysteroscopy could extend beyond the treatment of intrauterine abnormalities. Irrigation of the cavity with saline may have a beneficial effect on implantation and pregnancy rates, since saline mechanically washes harmful anti-adhesive glycoprotein molecules on the endometrial surface involved in endometrial receptivity, i.e., cyclooxygenase-2 (COX-2), mucin-1 (MUC-1), and integrin.ObjectiveThe aim of this study is to evaluate the role and benefit of routine hysteroscopy prior to ICSI in women with previous failed ICSI.Patients and methodsThis prospective study has been carried out, at the outpatient clinic, on 100 women that have undergone hysteroscopy as a part of the infertility workup. Women were categorized into three groups according to the number of previous failed IVF/ICSI, once (n = 37), twice (n = 33), and thrice (n = 30).ResultsAfter analyzing the data, we found that hysteroscopy was associated with 39% overall clinical pregnancy rate in women with previous/repeat IVF/ICSI failure. Treatment of polyp was associated with 58.3% clinical pregnancy rate (NNT = 1.71). Treatment of intrauterine adhesions was associated with 16.7% clinical pregnancy rate (NNT = 6). Treatment of submucous myoma and uterine septum showed a 75% and 50% clinical pregnancy rate, respectively.ConclusionHysteroscopic examination in women with previous failed ICSI may improve pregnancy rate even in the absence of uterine pathology. Consequently, hysteroscopy examination may be proposed as a routine step prior to ICSI in case of previous failure.

Genome-scale CRISPR activation screen uncovers tumor-intrinsic modulators of CD3 bispecific antibody efficacy

Bispecific antibodies (bsAb) that bridge tumor cells and CD3-positive effector T cells are being developed against many tumor cell targets. While tumor cell factors other than target expression level appear to play a role in determining the efficacy of CD3 bsAb, the identity of such factors remains largely unknown. Using a co-culture system of primary human T cells and B lymphoma cell lines, we demonstrate a range of sensitivities to CD20xCD3 bsAb that is independent of CD20 surface expression. To identify genes that modulate tumor cell sensitivity to CD3 bsAb, we employed a genome-scale CRISPR activation screen in a CD20xCD3-sensitive human B lymphoma cell line. Among the most highly enriched sgRNAs were those targeting genes with predicted effects on cell-cell adhesion, including sialophorin (SPN). Increased expression of SPN impeded tumor cell clustering with T cells, thereby limiting CD3 bsAb-mediated tumor cell lysis. This inhibitory effect of SPN appeared to be dependent on sialylated core 2 O-glycosylation of the protein. While SPN is not endogenously expressed in the majority of B cell lymphomas, it is highly expressed in acute myeloid leukemia. CRISPR-mediated SPN knockout in AML cell lines facilitated T cell-tumor cell clustering and enhanced CD3 bsAb-mediated AML cell lysis. In sum, our data establish that the cell cross-linking mechanism of CD3 bsAb is susceptible to subversion by anti-adhesive molecules expressed on the tumor cell surface. Further evaluation of anti-adhesive pathways may provide novel biomarkers of clinical response and enable the development of effective combination regimens for this promising therapeutic class.

Lubricin Antiadhesive Coatings Exhibit Size‐Selective Transport Properties that Inhibit Biofouling of Electrode Surfaces with Minimal Loss in Electrochemical Activity

AbstractElectrochemical sensing is a highly effective technique for rapidly detecting and quantifying the presence of electroactive compounds in solution. However, effective sensing requires the electrode surface to be free of contamination, which makes this technique particularly susceptible to the effects of surface fouling due to the unwanted adhesion of biomolecules. Unfortunately, coating electrodes with antiadhesive molecules typically causes electrical passivation with detrimental effects upon electrochemical processes. Lubricin is a large glycoprotein found in articular joints, which self‐assembles on most substrates and exhibits excellent antiadhesive properties. This report finds that lubricin antiadhesive coatings function as a size‐selective transport barrier that physically blocks large, fouling molecules (e.g., proteins) while still allowing small molecules to diffuse into, out‐of, and within this layer more‐or‐less unimpeded. The diffuse nature of the lubricin coatings ensures the electrode retains a large, “free” surface area that facilitates efficient charge transfer. Using cyclic voltammetry to measure the oxidation/reduction of a K3[Fe(CN)6] redox couple at a gold electrode (a system particularly susceptible to fouling), this report shows that antiadhesive lubricin brush coatings can be used for highly sensitive amperometric/voltametric detection of small electroactive compounds in highly fouling solutions of proteins and blood plasma with minimal, immediate impact upon the electrochemistry.

Reduction of Endothelial Nitric Oxide Increases the Adhesiveness of Constitutive Endothelial Membrane ICAM-1 through Src-Mediated Phosphorylation.

Nitric oxide (NO) is a known anti-adhesive molecule that prevents platelet aggregation and leukocyte adhesion to endothelial cells (ECs). The mechanism has been attributed to its role in the regulation of adhesion molecules on leukocytes and the adhesive properties of platelets. Our previous study conducted in rat venules found that reduction of EC basal NO synthesis caused EC ICAM-1-mediated firm adhesion of leukocytes within 10–30 min. This quick response occurred in the absence of alterations of adhesion molecules on leukocytes and also opposes the classical pattern of ICAM-1-mediated leukocyte adhesion that requires protein synthesis and occurs hours after stimulation. The objective of this study is to investigate the underlying mechanisms of reduced basal NO-induced EC-mediated rapid leukocyte adhesion observed in intact microvessels. The relative levels of ICAM-1 at different cell regions and their activation status were determined with cellular fractionation and western blot using cultured human umbilical vein ECs. ICAM-1 adhesiveness was determined by immunoprecipitation in non-denatured proteins to assess the changes in ICAM-1 binding to its inhibitory antibody, mAb1A29, and antibody against total ICAM-1 with and without NO reduction. The adhesion strength of EC ICAM-1 was assessed by atomic force microscopy (AFM) on live cells. Results showed that reduction of EC basal NO caused by the application of caveolin-1 scaffolding domain (AP-CAV) or NOS inhibitor, L-NMMA, for 30 min significantly increased phosphorylated ICAM-1 and its binding to mAb1A29 in the absence of altered ICAM-1 expression and its distribution at subcellular regions. The Src inhibitor, PP1, inhibited NO reduction-induced increases in ICAM-1 phosphorylation and adhesive binding. AFM detected significant increases in the binding force between AP-CAV-treated ECs and mAb1A29-coated probes. These results demonstrated that reduced EC basal NO lead to a rapid increase in ICAM-1 adhesive binding via Src-mediated phosphorylation without de novo protein synthesis and translocation. This study suggests that a NO-dependent conformational change of constitutive EC membrane ICAM-1 might be the mechanism of rapid ICAM-1 dependent leukocyte adhesion observed in vivo. This new mechanistic insight provides a better understanding of EC/leukocyte interaction-mediated vascular inflammation under many disease conditions that encounter reduced basal NO in the circulation system.

Rapid screening for specific glycosylation and pathogen interactions on a 78 species avian egg white glycoprotein microarray

There is an urgent need for discovery of novel antimicrobials and carbohydrate-based anti-adhesive strategies are desirable as they may not promote resistance. Discovery of novel anti-adhesive molecules from natural product libraries will require the use of a high throughput screening platform. Avian egg white (EW) provides nutrition for the embryo and protects against infection, with glycosylation responsible for binding certain pathogens. In this study, a microarray platform of 78 species of avian EWs was developed and profiled for glycosylation using a lectin panel with a wide range of carbohydrate specificities. The dominating linkages of sialic acid in EWs were determined for the first time using the lectins MAA and SNA-I. EW glycosylation similarity among the different orders of birds did not strictly depend on phylogenetic relationship. The interactions of five strains of bacterial pathogens, including Escherichia coli, Staphylococcus aureus and Vibrio cholera, identified a number of EWs as potential anti-adhesives, with some as strain- or species-specific. Of the two bacterial toxins examined, shiga-like toxin 1 subunit B bound to ten EWs with similar glycosylation more intensely than pigeon EW. This study provides a unique platform for high throughput screening of natural products for specific glycosylation and pathogen interactions. This platform may provide a useful platform in the future for discovery of anti-adhesives targeted for strain and species specificity.

Glucomannan's protective effect on the virulence of Vibrio splendidus in pacific oyster.

We examine the effect of Glucomannan, extracted from Candida utilis yeast, on immune parameters and resistance to Vibrio splendidus of Crassostreagigas. Our results showed that Glucomannan was a successful anti-adhesive molecule; it exhibited a stronger inhibitory effect on adhesion of Vibrio splendidus in infected Crassostreagigas. Vibrio splendidus viable cells number declined after incubation with Glucomannan. Furthermore, the Glucomannan diet showed higher activity to trigger the immune response against bacteria. Glucomannan applications, in biological control of seafood associated pathogens can be an alternative solution, providing consumer with a product of good quality owing to the use of 40 non-toxic compounds. Based on our results, Glucomannan could be used as a bio-protective culture in oyster's depuration to prevent Vibrio splendidus growth.

CD34 Promotes Pathological Epi-Retinal Neovascularization in a Mouse Model of Oxygen-Induced Retinopathy.

The sialomucins CD34 and podocalyxin (PODXL) are anti-adhesive molecules expressed at the luminal membrane of endothelial cells of small blood vessels and facilitate vascular lumen formation in the developing mouse aorta. CD34 transcript and protein levels are increased during human angiogenesis, its expression is particularly enriched on endothelial tip cell filopodia and CD34 is a marker for tip cells in vitro. Here, we investigated whether CD34 merely marks endothelial tip cells or has a functional role in tip cells and angiogenesis. We assessed that silencing CD34 in human microvascular endothelial cells has little effect on endothelial cell migration or invasion, but has a significant effect on vascular-endothelial growth factor-induced angiogenic sprouting activity in vitro. In vivo, the absence of CD34 reduced the density of filopodia on retinal endothelial tip cells in neonatal mice, but did not influence the overall architecture of the retinal vascular network. In oxygen-induced retinopathy, Cd34-/- mice showed normal intra-retinal regenerative angiogenesis but the number of pathological epi-retinal neovascular tufts were reduced. We conclude that CD34 is not essential for developmental vascularization in the retina, but its expression promotes the formation of pathological, invasive vessels during neovascularization.

Electrokinetic Properties of Lubricin Antiadhesive Coatings in Microfluidic Systems

Lubricin is a glycoprotein found in articular joints which has long been recognized as being an important biological boundary lubricant molecule and, more recently, an impressive antiadhesive that readily self-assembles into a well ordered, polymer brush layer on virtually any substrate. The lubricin molecule possesses an overabundance of anionic charge, a property that is atypical among antiadhesive molecules, that enables its use as a coating for applications involving electrokinetic processes such as electrophoresis and electroosmosis. Coating the surfaces of silica and polymeric microfluidic devices with self-assembled lubricin coatings affords a unique combination of excellent fouling resistance and high charge density that enables notoriously "sticky" biomolecules such as proteins to be used and controlled electrokinetically in the device without complications arising from nonspecific adsorption. Using capillary electrophoresis, we characterized the stability, uniformity, and electrokinetic properties of lubricin coatings applied to silica and PTFE capillaries over a range of run buffer pHs and when exposed to concentrated solutions of protein. In addition, we demonstrate the effectiveness of lubricin as a coating to minimize nonspecific protein adsorption in an electrokinetically controlled polydimethylsiloxane/silica microfluidic device.

MEK inhibitors, novel anti-adhesive molecules, reduce sickle red blood cell adhesion in vitro and in vivo, and vasoocclusion in vivo.

In sickle cell disease, sickle erythrocyte (SSRBC) interacts with endothelial cells, leukocytes, and platelets, and activates coagulation and inflammation, promoting vessel obstruction, which leads to serious life-threatening complications, including acute painful crises and irreversible damage to multiple organs. The mitogen-activated protein kinase, ERK1/2, is abnormally activated in SSRBCs. However, the therapeutic potential of SSRBC ERK1/2 inactivation has never been investigated. I tested four different inhibitors of MEK1/2 (MEK), the kinase that activates ERK1/2, in a model of human SSRBC adhesion to TNFα-activated endothelial cells (ECs). SSRBC MEK inhibition abrogated adhesion to non-activated and TNFα-activated ECs to levels below baseline SSRBC adhesion to non-activated ECs in vitro. SSRBC MEK inhibition also prevented SSRBCs from activating naïve neutrophils to adhere to endothelium. To determine the effect of MEK inhibitors on SSRBC adherence in vivo, sham-treated or MEK inhibitor-treated SSRBCs were infused to nude mice previously treated with TNFα. Sham-treated SSRBCs displayed marked adhesion and occlusion of enflamed vessels, both small and large. However, SSRBC treatment with MEK inhibitors ex vivo showed poor SSRBC adhesion to enflamed vessels with no visible vasoocclusion in vivo. In addition, MEK inhibitor treatment of SSRBCs reduced SSRBC organ trapping and increased the number of SSRBCs circulating in bloodstream. Thus, these data suggest that SSRBC ERK1/2 plays potentially a critical role in sickle pathogenesis, and that MEK inhibitors may represent a valuable intervention for acute sickle cell crises.

A proteinaceous fraction of wheat bran may interfere in the attachment of enterotoxigenic E. coli K88 (F4+) to porcine epithelial cells.

Wheat bran (WB) from Triticum aestivum has many beneficial effects on human health. To the best of our knowledge, very little has been published about its ability to prevent pathogenic bacterial adhesion in the intestine. Here, a WB extract was fractionated using different strategies, and the obtained fractions were tested in different in vitro methodologies to evaluate their interference in the attachment of enterotoxigenic Escherichia coli (ETEC) K88 to intestinal porcine epithelial cells (IPEC-J2) with the aim of identifying the putative anti-adhesive molecules. It was found that a proteinaceous compound in the >300-kDa fraction mediates the recognition of ETEC K88 to IPEC-J2. Further fractionation of the >300-kDa sample by size-exclusion chromatography showed several proteins below 90 kDa, suggesting that the target protein belongs to a high-molecular-weight (MW) multi-component protein complex. The identification of some relevant excised bands was performed by mass spectrometry (MS) and mostly revealed the presence of various protease inhibitors (PIs) of low MW: Serpin-Z2B, Class II chitinase, endogenous alpha-amylase/subtilisin inhibitor and alpha-amylase/trypsin inhibitor CM3. Furthermore, an incubation of the WB extract with ETEC K88 allowed for the identification of a 7S storage protein globulin of wheat, Globulin 3 of 66 kDa, which may be one of the most firmly attached WB proteins to ETEC K88 cells. Further studies should be performed to gain an understanding of the molecular recognition of the blocking process that takes place. All gathered information can eventually pave the way for the development of novel anti-adhesion therapeutic agents to prevent bacterial pathogenesis.