Astrocyte targets

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The expression of MAFG in mice is high compared to human (Data from public data bases

MAFG-driven astrocytes promote CNS inflammation. Wheeler MA, Clark IC, Tjon EC, Li Z, Zandee SEJ, Couturier CP, Watson BR, Scalisi G, Alkwai S, Rothhammer V, Rotem A, Heyman JA, Thaploo S, Sanmarco LM, Ragoussis J, Weitz DA, Petrecca K, Moffitt JR, Becher B, Antel JP, Prat A, Quintana FJ.Nature. 2020 Feb 12. doi: 10.1038/s41586-020-1999-0. [Epub ahead of print]

Multiple sclerosis is a chronic inflammatory disease of the CNS. Astrocytes contribute to the pathogenesis of multiple sclerosis, but little is known about the heterogeneity of astrocytes and its regulation. Here we report the analysis of astrocytes in multiple sclerosis and its preclinical model experimental autoimmune encephalomyelitis (EAE) by single-cell RNA and other sequencing. We identified astrocytes in EAE and multiple sclerosis that were characterized by decreased expression of NRF2 and increased expression of MAFG, which cooperates with MAT2α to represses antioxidant and anti-inflammatory transcriptional programs. Granulocyte-macrophage colony-stimulating factor (GM-CSF) signalling in astrocytes drives the expression of MAFG and MAT2α and pro-inflammatory transcriptional modules, contributing to CNS pathology in EAE and, potentially, multiple sclerosis. Our results identify candidate therapeutic targets in multiple sclerosis.

This study went on a fishing trip to see what astrocytes were doing and pulled out a few targets.Will they be useful targets in MS? I don’t know but some of them are signalling molecules. I would say that I am not sure how good these are as targets. You not only have to get enough drug into brain then you have to get them in the cells and importantly these often lack specificity as they are found all over the place as is the case of MAFG. Recepors give the specificity the signalling molecules don’t. Why invent a new activation signalling pathway if you don’t need too. But hey what do I know? I got slagged off for picking some drug targets. But I say if you don’t know anything about the biology of the target and what it is doing, it is best to keep your mouth shut in case you look like a fool in the future. Therefore, I won’t say more until I interogate this information….More data to trawl.

Nuclear factor erythroid 2-related factor 2 (NRF2), also known as nuclear factor erythroid-derived 2-like 2, is a transcription factor that that regulates the expression of antioxidant proteins that protect against oxidative damage triggered by injury and inflammation. Dimethyl fumarate (and its metabolite, monomethyl fumarate) activates the NRF2 pathway. NFE2L2 has been shown to interact with MAFFMAFGMAFKC-junCREBBPEIF2AK3KEAP1, and UBC. MafG gene expression is induced by oxidative stresses including .Mouse Mafg gene is induced by Nrf2-sMaf heterodimers through an antioxidant response element

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MouseDoctor

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  • Hi Mouse Doc
    Hope you’re having a nice Sunday.
    This article goes over my head a bit so I will need to google what an Astrocyte is but I had a sort of related or maybe unrelated question as I try to understand how MS drugs are all made with mice experiments.
    I read on an Ocrevus leaflet that it was made from Chinese hamster ovary cells. What does this mean? It sounds pretty cool, unless you’re vegan. Is my Ocrevus harvested inside a hamster or am I completely wrong, science is not my strong point 🙂
    Thanks

    • Much of the work behind production of monoclonal antibodies is rooted in the production of hybridomas, which involves identifying antigen-specific plasma/plasmablast cells (ASPCs) that produce antibodies specific to an antigen of interest and fusing these cells with myeloma cells.[citation needed] Rabbit B-cells can be used to form a rabbit hybridoma. Polyethylene glycol is used to fuse adjacent plasma membranes,[7] but the success rate is low, so a selective medium in which only fused cells can grow is used. This is possible because myeloma cells have lost the ability to synthesize hypoxanthine-guanine-phosphoribosyl transferase (HGPRT), an enzyme necessary for the salvage synthesis of nucleic acids. The absence of HGPRT is not a problem for these cells unless the de novo purine synthesis pathway is also disrupted. Exposing cells to aminopterin (a folic acid analogue, which inhibits dihydrofolate reductase, DHFR), makes them unable to use the de novo pathway and become fully auxotrophic for nucleic acids, thus requiring supplementation to survive.

      The selective culture medium is called HAT medium because it contains hypoxanthine, aminopterin and thymidine. This medium is selective for fused (hybridoma) cells. Unfused myeloma cells cannot grow because they lack HGPRT and thus cannot replicate their DNA. Unfused spleen cells cannot grow indefinitely because of their limited life span. Only fused hybrid cells, referred to as hybridomas, are able to grow indefinitely in the medium because the spleen cell partner supplies HGPRT and the myeloma partner has traits that make it immortal (similar to a cancer cell).

      This mixture of cells is then diluted and clones are grown from single parent cells on microtitre wells. The antibodies secreted by the different clones are then assayed for their ability to bind to the antigen (with a test such as ELISA or Antigen Microarray Assay) or immuno-dot blot. The most productive and stable clone is then selected for future use.

      The hybridomas can be grown indefinitely in a suitable cell culture medium. They can also be injected into mice (in the peritoneal cavity, surrounding the gut). There, they produce tumors secreting an antibody-rich fluid called ascites fluid.

      The medium must be enriched during in vitro selection to further favour hybridoma growth. This can be achieved by the use of a layer of feeder fibrocyte cells or supplement medium such as briclone. Culture-media conditioned by macrophages can be used. Production in cell culture is usually preferred as the ascites technique is painful to the animal. Where alternate techniques exist, ascites is considered unethical.[8]

      https://en.m.wikipedia.org/wiki/Monoclonal_antibody

        • Hybridoma technology is a method for producing large numbers of identical antibodies (also called monoclonal antibodies). This process starts by injecting a mouse (or other mammal) with an antigen that provokes an immune response. A type of white blood cell, the B cell, produces antibodies that bind to the injected antigen. These antibody producing B-cells are then harvested from the mouse and, in turn, fused with immortal B cell cancer cells, a myeloma,[clarification needed] to produce a hybrid cell line called a hybridoma, which has both the antibody-producing ability of the B-cell and the longevity and reproductivity of the myeloma. The hybridomas can be grown in culture, each culture starting with one viable hybridoma cell, producing cultures each of which consists of genetically identical hybridomas which produce one antibody per culture (monoclonal) rather than mixtures of different antibodies (polyclonal). The myeloma cell line that is used in this process is selected for its ability to grow in tissue culture and for an absence of antibody synthesis. In contrast to polyclonal antibodies, which are mixtures of many different antibody molecules, the monoclonal antibodies produced by each hybridoma line are all chemically identical.

          The production of monoclonal antibodies was invented by César Milstein and Georges J. F. Köhler in 1975. They shared the Nobel Prize of 1984 for Medicine and Physiology with Niels Kaj Jerne, who made other contributions to immunology. The term hybridoma was coined by Leonard Herzenberg during his sabbatical in César Milstein’s laboratory in 1976–1977.[1]

          https://en.wikipedia.org/wiki/Hybridoma_technology

    • It goes over mine too so don’t worry.

      If you look back through the blog there are posts on the histology and the cell type (astro cyte = star-shaped cell). I will do a post about chinese hamsters…your antibody does not come directly from an animal.

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