Abstract
Genetic variants of high-temperature requirement A serine peptidase 1 (HTRA1) and age-related maculopathy susceptibility 2 (ARMS2) are associated with age-related macular degeneration (AMD). One HTRA1 single nucleotide polymorphism (SNP) is situated in the promotor region (rs11200638) resulting in increased expression, while two synonymous SNPs are located in exon 1 (rs1049331:C > T, rs2293870:G > T). HtrA1 is known to inhibit transforming growth factor-β (TGF-β) signaling, a pathway regulating quiescence of microglia, the resident immune cells of the brain and retina. Microglia-mediated immune responses contribute to AMD pathogenesis. It is currently unclear whether AMD-associated HTRA1 variants influence TGF-β signaling and microglia phenotypes. Here, we show that an HtrA1 isoform carrying AMD-associated SNPs in exon 1 exhibits increased proteolytic activity. However, when incubating TGF-β-treated reactive microglia with HtrA1 protein variants, neither the wildtype nor the SNP-associated isoforms changed microglia activation in vitro.
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Akhtar-Schaefer, I., Reuten, R., Koch, M., Pietsch, M., Langmann, T. (2019). AMD-Associated HTRA1 Variants Do Not Influence TGF-β Signaling in Microglia. In: Bowes Rickman, C., Grimm, C., Anderson, R., Ash, J., LaVail, M., Hollyfield, J. (eds) Retinal Degenerative Diseases. Advances in Experimental Medicine and Biology, vol 1185. Springer, Cham. https://doi.org/10.1007/978-3-030-27378-1_1
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DOI: https://doi.org/10.1007/978-3-030-27378-1_1
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