A sandwich ELISA for the detection of Wnt5a

Mechanisms of the Wnt Pathways as a Potential Target Pathway in Atherosclerosis

The proteins of the Wnt family are involved in a variety of physiological processes by means of several canonical and noncanonical signaling pathways. Wnt signaling has been recently identified as a major player in atherogenesis. In this review, we summarize the existing knowledge on the influence of various components of the Wnt signaling pathways on the initiation and progression of atherosclerosis and associated conditions. We used the PubMed database to search for recent papers on the involvement of the Wnt pathways in atherosclerosis. We used the combination of "Wnt" and "atherosclerosis" keywords to find the initial papers, and chose papers published after 2018. In the first section of the paper, we describe the general mechanisms of the Wnt signaling pathways and their components. The next section is dedicated to existing studies assessing the implication of Wnt signaling elements in different atherogenic processes, such as cholesterol retention, endothelial dysfunction, vascular inflammation, and atherosclerotic calcification of the vessels. Lastly, various therapeutic strategies based on interference with the Wnt signaling pathways are considered. We also compare the efficacy and availability of the proposed treatment methods. Wnt signaling can be considered a potential target in the treatment and prevention of atherosclerosis. Therefore, in this review, we reviewed evidences showing that wnt signaling is an important signal for developing appropriate treatment strategies for atherosclerosis.

Stool Serology: Development of a Non-Invasive Immunological Method for the Detection of Enterovirus-Specific Antibodies in Congo Gorilla Faeces

Background: The incidence of poliovirus has been significantly reduced by as much as 99.9% globally. Alongside this, however, vaccine-associated paralytic poliomyelitis has emerged. Previously, our team reported in the Lésio-Louna-Léfini Nature Reserve (Republic of Congo) the presence of a new Enterovirus C (Ibou002) in a male gorilla that was put away because of clinical symptoms of facial paralysis. This new virus, isolated was from the stool samples of this gorilla but also from the excrement of an eco-guardian, is very similar to Coxsackievirus (EV-C99) as well as poliovirus 1 and 2. We hypothesised that these symptoms might be due to poliovirus infection. To test our hypothesis, we developed and optimised a non-invasive immunoassay for the detection of Enterovirus-specific antibodies in gorilla faeces that could be useful for routine serosurveillance in such cases. Methods: In order to assess the potential role of poliovirus infection, we have developed and optimised a protocol, based on the lyophilisation and solubilisation of small volumes of stool extracts from 16 gorilla and 3 humans, to detect specific antibodies by western blot and ELISA. Results: First, total immunoglobulins were detected in the concentrated stool extracts. Specific antibodies were then detected in 4/16 gorilla samples and 2/3 human samples by western blot using both the polio vaccine antigen and the Ibou002 antigen and by ELISA using the polio vaccine antigen. Humoral responses were greater with the Ibou002 antigen. Conclusion: We therefore suggest that this recombinant virus could lead to a polio-like disease in the endangered western lowland gorilla. The development of a non-invasive approach to detect microorganism-specific immunoglobulins from faecal samples opens numerous prospects for application in zoonotic infectious diseases and could revolutionise the screening of animals for important emerging infections, such as Ebola fever, rabies and coronavirus infections.

Wnt5a: a player in the pathogenesis of atherosclerosis and other inflammatory disorders

OBJECTIVE

The objective of this article is to review the current literature on Wnt5a and its signaling mechanism, along with its role in atherosclerosis. In addition, the significance of Wnt5a as a diagnostic marker and a potential therapeutic target is reviewed. Wnt5a, a secreted glycoprotein, belongs to a family of highly conserved proteins that regulate important processes such as cell fate specification, embryonic development, cell proliferation, migration, and differentiation in a variety of organisms. The complexity of Wnt5a signaling lies in the fact that Wnt5a can bind to different classes of frizzled receptors, receptor tyrosine kinase-like orphan receptor 2, as well as co-receptors such as low density lipoprotein receptor-related protein 5/6. Wnt5a signals primarily through the non-canonical pathway, where it mediates cell proliferation, adhesion, and movement. However, the role of Wnt5a in canonical signaling is still unresolved. Depending on the receptor availability, Wnt5a can serve to activate or inhibit the canonical Wnt signaling pathway. Due to the promiscuous nature of Wnt5a, it has been extremely difficult to fully understand its signaling mechanism. Wnt5a has recently emerged as a macrophage effector molecule that triggers inflammation. Perturbations in Wnt5a signaling have been reported in several inflammatory diseases, particularly in sepsis, rheumatoid arthritis, and atherosclerosis.

CONCLUSION

Both existing and emerging evidence suggests that the expression of Wnt5a is always up-regulated in these, and possibly other inflammatory disorders. This knowledge can be useful for targeting Wnt5a and/or its receptor and downstream signaling molecules for therapeutic intervention in inflammatory disorders.

Role of non-canonical Wnt signaling in osteoblast maturation on microstructured titanium surfaces

The Wnt signaling pathway inhibitor Dickkopf-2 (Dkk2) regulates osteoblast differentiation on microstructured titanium (Ti) surfaces, suggesting involvement of Wnt signaling in this process. To test this, human osteoblast-like MG63 cells were cultured on tissue culture polystyrene or Ti (smooth PT (Ra=0.2 μm), sand-blasted and acid-etched SLA (Ra=3.22 μm), modSLA (hydrophilic SLA)). Expression of Wnt pathway receptors, activators and inhibitors was measured by qPCR. Non-canonical pathway ligands, receptors and intracellular signaling molecules, as well as bone morphogenetic proteins BMP2 and BMP4, were upregulated on SLA and modSLA, whereas canonical pathway members were downregulated. To confirm that non-canonical signaling was involved, cells were cultured daily with exogenous Wnt3a (canonical pathway) or Wnt5a (non-canonical pathway). Alternatively, cells were cultured with antibodies to Wnt3a or Wnt5a to validate that Wnt proteins secreted by the cells were mediating cell responses to the surface. Wnt5a, but not Wnt3a, increased MG63 cell differentiation and BMP2 and BMP4 proteins, suggesting Wnt5a promotes osteogenic differentiation through production of BMPs. Effects of exogenous and endogenous Wnt5a were synergistic with surface microstructure, suggesting the response also depends on cell maturation state. These results indicate a major role for the non-canonical, calcium-dependent Wnt pathway in differentiation of osteoblasts on microstructured titanium surfaces during implant osseointegration.

Role of non-canonical Wnt signaling in osteoblast maturation on microstructured titanium surfaces

The Wnt signaling pathway inhibitor Dickkopf-2 (Dkk2) regulates osteoblast differentiation on microstructured titanium (Ti) surfaces, suggesting involvement of Wnt signaling in this process. To test this, human osteoblast-like MG63 cells were cultured on tissue culture polystyrene or Ti (smooth PT (Ra=0.2 μm), sand-blasted and acid-etched SLA (Ra=3.22 μm), modSLA (hydrophilic SLA)). Expression of Wnt pathway receptors, activators and inhibitors was measured by qPCR. Non-canonical pathway ligands, receptors and intracellular signaling molecules, as well as bone morphogenetic proteins BMP2 and BMP4, were upregulated on SLA and modSLA, whereas canonical pathway members were downregulated. To confirm that non-canonical signaling was involved, cells were cultured daily with exogenous Wnt3a (canonical pathway) or Wnt5a (non-canonical pathway). Alternatively, cells were cultured with antibodies to Wnt3a or Wnt5a to validate that Wnt proteins secreted by the cells were mediating cell responses to the surface. Wnt5a, but not Wnt3a, increased MG63 cell differentiation and BMP2 and BMP4 proteins, suggesting Wnt5a promotes osteogenic differentiation through production of BMPs. Effects of exogenous and endogenous Wnt5a were synergistic with surface microstructure, suggesting the response also depends on cell maturation state. These results indicate a major role for the non-canonical, calcium-dependent Wnt pathway in differentiation of osteoblasts on microstructured titanium surfaces during implant osseointegration.

A Thymidine Kinase recombinant protein-based ELISA for detecting antibodies to Duck Plague Virus

BACKGROUND

Duck plague virus (DPV) is the causative agent of Duck Plague (DP) that causes significant morbidity and mortality throughout duck-producing areas of the world. The diagnosis of DP currently relies on the use of live or inactivated whole DPV virion as antigens in ELISA, but it is too laborious and expensive for routine application, and it is still difficult to get purified DPV virion with current technology.

RESULTS

In this study, we describe the expression and purification of a recombinant Thymidine Kinase (TK) protein which makes antigen in an in-house developed, optimized and standardized ELISA. The specificity of the optimized TK-ELISA was evaluated by antisera against Duck Plague Virus (DPV), Duck Hepatitis B Virus (DHBV), Duck Hepatitis Virus (DHV), Riemerella Anatipestifer(R. A), Escherichia coli (E. coli) and Salmonella anatum (S. anatum). Only antisera against DPV yielded a specific and strong signal. In order to determine the sensitivity of the TK-ELISA, a panel of diluted sera was tested, and the minimum detection limit of 1:2560 (OD450 nm = 0.401) was obtained according to the endpoint cut-off (0.2438). The repeatability and reproducibility under the experimental conditions demonstrates a low variability (P > 0.05). The suspected sera samples (n = 30) were determined by TK-ELISA and the positive rate is 90% (27/30), and the TK-ELISA showed 83.33% (22+3/30) coincidence rate with the Serum Neutralization Test (SNT) and 90% (24+3/30) coincidence rate with the whole DPV virion based-ELISA (DPV-ELISA). When defining the dynamics of antibody response to attenuated live DPV vaccine, the maximum antibodies is reached after 4 weeks.

CONCLUSIONS

The results suggest that the TK-ELISA provides high specificity, sensitivity, repeatability and reproducibility for detection of anti-DPV antibodies in duck sera, and has the potential to be much simpler than DPV-ELISA and SNT for the sera epidemiological investigation.