Systematic analysis of the transmembrane domain interactions : from the interleukine-10 and AMIGO3 receptor to all tyrosine kinase receptors

Le domaine transmembranaire (TM) des protéines membranaires possède des rôles clefs dans l’oligomérisation et l’activation des récepteurs. Dans le cadre de ce travail, nous avons à la fois démontré son importance dans l’activation du récepteur AMIGO3 et dans l’oligomérisation des sous-unités α et β du récepteur de l’interleukine 10. Des peptides mimant les séquences TM de ces récepteurs ont permis de moduler leur activation et celle des voies de signalisation sous-jacentes. Le peptide ciblant AMIGO3 est capable d’améliorer les signes cliniques dans un modèle de sclérose en plaques, alors que les peptides ciblant l’IL-10R possèdent des effets in vitro dans un modèle de glioblastome. Face à ces nouveaux exemples soulignant l’importance du domaine TM, nous avons réalisé une analyse systématique des interactions entre domaines TM par un test de BRET. L’interactome complet des domaines TM des 58 récepteurs à activité tyrosine kinase et de six récepteurs à dépendance a ainsi été réalisé. Ce résultat mène vers la conception d’un outil de compréhension des interactions entre domaines TM et de conception de peptides thérapeutiques ciblant n’importe quel récepteur.The transmembrane (TM) domain of membrane proteins has key roles in receptor oligomerisation and activation. In this work, we have demonstrated its importance in the activation of the AMIGO3 receptor and in the oligomerisation of the α and β subunits of the interleukin 10 receptor. Peptides mimicking the TM sequences of these receptors were used to modulate their activation and that of the underlying signalling pathways. The peptide targeting AMIGO3 is able to improve clinical signs in a multiple sclerosis model, while peptides targeting IL-10R have in vitro effects in a glioblastoma model. With these new examples highlighting the importance of the TM domain, we performed a systematic analysis of TM domain interactions using a BRET assay. The complete TM domain interactome of the 58 tyrosine kinase receptors and six dependence receptors has been completed. This result leads to the design of a tool to understand the interactions between TM domains and thus to design therapeutic peptides targeting any receptor

Systematic analysis of the transmembrane domain interactions : from the interleukine-10 and AMIGO3 receptor to all tyrosine kinase receptors

Le domaine transmembranaire (TM) des protéines membranaires possède des rôles clefs dans l’oligomérisation et l’activation des récepteurs. Dans le cadre de ce travail, nous avons à la fois démontré son importance dans l’activation du récepteur AMIGO3 et dans l’oligomérisation des sous-unités α et β du récepteur de l’interleukine 10. Des peptides mimant les séquences TM de ces récepteurs ont permis de moduler leur activation et celle des voies de signalisation sous-jacentes. Le peptide ciblant AMIGO3 est capable d’améliorer les signes cliniques dans un modèle de sclérose en plaques, alors que les peptides ciblant l’IL-10R possèdent des effets in vitro dans un modèle de glioblastome. Face à ces nouveaux exemples soulignant l’importance du domaine TM, nous avons réalisé une analyse systématique des interactions entre domaines TM par un test de BRET. L’interactome complet des domaines TM des 58 récepteurs à activité tyrosine kinase et de six récepteurs à dépendance a ainsi été réalisé. Ce résultat mène vers la conception d’un outil de compréhension des interactions entre domaines TM et de conception de peptides thérapeutiques ciblant n’importe quel récepteur.The transmembrane (TM) domain of membrane proteins has key roles in receptor oligomerisation and activation. In this work, we have demonstrated its importance in the activation of the AMIGO3 receptor and in the oligomerisation of the α and β subunits of the interleukin 10 receptor. Peptides mimicking the TM sequences of these receptors were used to modulate their activation and that of the underlying signalling pathways. The peptide targeting AMIGO3 is able to improve clinical signs in a multiple sclerosis model, while peptides targeting IL-10R have in vitro effects in a glioblastoma model. With these new examples highlighting the importance of the TM domain, we performed a systematic analysis of TM domain interactions using a BRET assay. The complete TM domain interactome of the 58 tyrosine kinase receptors and six dependence receptors has been completed. This result leads to the design of a tool to understand the interactions between TM domains and thus to design therapeutic peptides targeting any receptor

Manipulating Macrophage/Microglia Polarization to Treat Glioblastoma or Multiple Sclerosis

Macrophages and microglia are implicated in several diseases with divergent roles in physiopathology. This discrepancy can be explained by their capacity to endorse different polarization states. Theoretical extremes of these states are called M1 and M2. M1 are pro-inflammatory, microbicidal, and cytotoxic whereas M2 are anti-inflammatory, immunoregulatory cells in favor of tumor progression. In pathological states, these polarizations are dysregulated, thus restoring phenotypes could be an interesting treatment approach against diseases. In this review, we will focus on compounds targeting macrophages and microglia polarization in two very distinctive pathologies: multiple sclerosis and glioblastoma. Multiple sclerosis is an inflammatory disease characterized by demyelination and axon degradation. In this case, macrophages and microglia endorse a M1-like phenotype inducing inflammation. Promoting the opposite M2-like polarization could be an interesting treatment strategy. Glioblastoma is a brain tumor in which macrophages and microglia facilitate tumor progression, spreading, and angiogenesis. They are part of the tumor associated macrophages displaying an anti-inflammatory phenotype, thereby inhibiting anti-tumoral immunity. Re-activating them could be a method to limit and reduce tumor progression. These two pathologies will be used to exemplify that targeting the polarization of macrophages and microglia is a promising approach with a broad spectrum of applications deserving more attention

Handheld Fluorescence Spectrometer Enabling Sensitive Aflatoxin Detection in Maize

Aflatoxins are among the main carcinogens threatening food and feed safety while imposing major detection challenges to the agrifood industry. Today, aflatoxins are typically detected using destructive and sample-based chemical analysis that are not optimally suited to sense their local presence in the food chain. Therefore, we pursued the development of a non-destructive optical sensing technique based on fluorescence spectroscopy. We present a novel compact fluorescence sensing unit, comprising both ultraviolet excitation and fluorescence detection in a single handheld device. First, the sensing unit was benchmarked against a validated research-grade fluorescence setup and demonstrated high sensitivity by spectrally separating contaminated maize powder samples with aflatoxin concentrations of 6.6 µg/kg and 11.6 µg/kg. Next, we successfully classified a batch of naturally contaminated maize kernels within three subsamples showing a total aflatoxin concentration of 0 µg/kg, 0.6 µg/kg and 1647.8 µg/kg. Consequently, our novel sensing methodology presents good sensitivity and high potential for integration along the food chain, paving the way toward improved food safety

Toward a Combination of Biomarkers for Molecular Characterization of Multiple Sclerosis

Multiple sclerosis (MS) is an autoimmune disease affecting the central nervous system associated with chronic inflammation, demyelination, and axonal damage. MS is a highly heterogeneous disease that leads to discrepancies regarding the clinical appearance, progression, and therapy response of patients. Therefore, there is a strong unmet need for clinically relevant biomarkers capable of recapitulating the features of the disease. Experimental autoimmune encephalomyelitis (EAE) is a valuable model for studying the pathophysiology of MS as it recapitulates the main hallmarks of the disease: inflammation, blood-brain barrier (BBB) disruption, gliosis, myelin damage, and repair mechanisms. In this study, we used the EAE-PLP animal model and established a molecular RNA signature for each phase of the disease (onset, peak, remission). We compared variances of expression of known biomarkers by RT-qPCR in the brain and spinal cord of sham and EAE animals monitoring each of the five hallmarks of the disease. Using magnetic cell isolation technology, we isolated microglia and oligodendrocytes of mice of each category, and we compared the RNA expression variations. We identify genes deregulated during a restricted time frame, and we provide insight into the timing and interrelationships of pathological disease processes at the organ and cell levels