Glial Fibrillary Acidic Protein (GFAP) was discovered by Amico Bignami and coworkers as a major fibrous protein of multiple sclerosis plaques (1). It was subsequently found to be a member of the 10nm or intermediate filament protein family, specifically the intermediate filament protein family Class III, which also includes peripherin, desmin and vimentin. The GFAP protein runs on gels as a ~50kDa protein, usually associated with somewhat lower molecule weight bands which are alternate transcripts from the single gene. The HGNC nomenclature for this protein is, perhaps not surprisingly, GFAP. GFAP is strongly and specifically expressed in astrocytes and certain other astroglia in the central nervous system, in satellite cells in peripheral ganglia, and in non-myelinating Schwann cells in peripheral nerves (2,3). It is also a component of neural stem cells.
Astrocytes respond to many damage and disease states resulting in “astrogliosis” or the presence of a “glial response”. GFAP antibodies are widely used to see the reactive astrocytes which form part of this response, since reactive astrocytes stain much more strongly with GFAP antibodies than normal astrocytes. GFAP also forms a major component of the so-called glial scar, an astrocyte rich structure apparently forming part of the barrier to nerve fiber regeneration following damage in the central nervous system (4).
Neural stem cells frequently strongly express GFAP. Antibodies to GFAP are therefore very useful as markers of normal and reactive astrocytic cells and neural stem cells. Finally, Alexander disease was recently shown to be caused by point mutations in the protein coding region of the GFAP gene (5). All forms of Alexander disease are characterized by the presence of Rosenthal fibers, which are GFAP containing cytoplasmic inclusions found in astrocytes. Some interest has recently been focused on GFAP as a protein released into blood and CSF following traumatic brain injury, stroke and other CNS compromises (6,7). Measurement of the levels of blood or CSF GFAP may give information about patient presentation, progress, response to therapy or outcome.
Our antibody produces strong and specific staining on western blots, in immunocytochemistry (see below) and on formalin fixed paraffin embedded sections (see here).
Immunofluorescent analysis of a cortical neuron-glial cell culture from E20 rat stained with mouse mAb to GFAP, MCA-5C10, dilution 1:1,000 in red, and costained with chicken pAb to NF-L, CPCA-NF-L, dilution 1:2,000 in red. The blue is DAPI staining of nuclear DNA. MCA-5C10 antibody stains developing and mature astrocytic cells, while the NFL antibody reveals dendrites and axons of neurons. Mouse select image for larger view.
This is one of a series of formalin fixed paraffin embedded adult horse brain samples generated by Maureen T. Long in the Department of Infectious Diseases and Pathology, College of Veterinary Medicine, University of Florida. The findings were recently published in the Equine Veterinary Journal, link here. The brains from this series were removed whole, sliced incompletely cross ways and fixed over a 10-20 day period. The whole brain was put in a large necropsy specimen bucket containing 1-2 gallons of fixative, and after 24 hours, the formalin was poured off and then fresh formalin was added. The samples were fixed and embedded in paraffin in 2007 and sections were kept at room temperature until 2011. The sections were processed for antigen retrieval by boiling in pH=6 Citrate buffer for 10 min. Primary incubation with MCA-5C10 was for 1 hour at 37°C, and secondary antibody incubation and color reaction was performed using the Vector mouse ABC kit. Mouse select image for larger view.
This antibody is widely sold through EnCor OEM partners, and a growing list of peer-reviewed publications cite EnCor as origin of this antibody, see here.
1. Bignami A, Eng LF, Dahl D, Uyeda CT. Localization of the glial fibrillary acidic protein in astrocytes by immunofluorescence. Brain Res. 43:429-35 (1972).2. Yen SH, Fields KL. Antibodies to neurofilament, glial filament, and fibroblast intermediate filament proteins bind to different cell types of the nervous system. J Cell Biol. 88:115-26 (1981).3. Shaw G, Osborn M, Weber K. An immunofluorescence microscopical study of the neurofilament triplet proteins, vimentin and glial fibrillary acidic protein within the adult rat brain. Eur. J. Cell Biol. 26:68-82 (1981).4. Fitch MT, Silver J. CNS injury, glial scars, and inflammation: Inhibitory extracellular matrices and regeneration failure. Exp. Neurol. 209:294-301 (2008).5. Brenner M, et al. Mutations in GFAP, encoding glial fibrillary acidic protein, are associated with Alexander disease. Nat. Genet. 27:117-20 2001.6. Foerch, C. et al. Diagnostic accuracy of plasma glial fibrillary acidic protein for differentiating intracerebral hemorrhage and cerebral ischemia in patients with symptoms of acute stroke. Clin Chem. 58:237-45 (2011).7. Schiff L, Hadker N, Weiser S, Rausch C. A literature review of the feasibility of glial fibrillary acidic protein as a biomarker for stroke and traumatic brain injury. Mol. Diagn. Ther. 16:79-92 (2012).
Recent peer reviewed publications using this antibody.
1. de Kloet AD, et al.Reporter mouse strain provides a novel look at angiotensin type-2 receptor distribution in the central nervous system.Brain Struct. Funct. 22:891-912 (2016).2. Silva MC, et al. Human iPSC-Derived Neuronal Model of Tau-A152T Frontotemporal Dementia Reveals Tau-Mediated Mechanisms of Neuronal Vulnerability. Stem Cell Res. 7:325-40 (2016).3. Edamakanti CR, et al. Mutant ataxin disrupts cerebellar development in spinocerebellar ataxia type 1 J. Clin. Invest. 128:2252-65 (2018).
The antibody has also been sold through many OEM partners, and peer-reviewed publications making use of it can be found by searching Google Scholar for “5C10 AND GFAP AND antibody” or, if you are viewing this online, simply by selecting this link.
