The A53T mutation in α-synuclein enhances pro-inflammatory activation in human microglia

Abstract

Parkinson's disease (PD) is characterized by the aggregation of alpha-synuclein into Lewy bodies and Lewy neurites in the brain. Microglia-driven neuroinflammation may contribute to neuronal death in PD, however the exact role of microglia remains unclear and has been understudied. The A53T mutation in the gene coding for alpha-synuclein has been linked to early-onset PD, and exposure to A53T-mutant human alpha-synuclein increases the potential for inflammation of murine microglia. To date, its effect has not been studied in human microglia. Here, we used 2-dimensional cultures of human iPSC-derived microglia and transplantation of these cells into the mouse brain to assess the effects of the A53T mutation on human microglia. We found that A53T-mutant human microglia had an intrinsically increased propensity towards pro-inflammatory activation upon inflammatory stimulus. Additionally, A53T mutant microglia showed a strong decrease in catalase expression in non-inflammatory conditions, and increased oxidative stress. Our results indicate that A53T mutant human microglia display cell-autonomous phenotypes that may worsen neuronal damage in early-onset PD.

Human-specific paralogs of SRGAP2 induce neotenic features of microglia structural and functional maturation

“…HiPSCs lines used in this study were previously generated and characterized in the Jaenisch Lab 77 . The cell lines used for the morphological characterization of wild-type human microglia, WIBR-hiPS-SNCA A53T-Corr , stably expressed Green Fluorescent Protein (GFP) from the AAVS1-locus after targeting with a Zinc-Finger GFP-expressing AAV, as previously described 78,79 . The cell line used for Srgap2b/c knock-down experiments, WIBR-hiPS-SNCA A53T-Corr , was unlabeled.…”

“…HiPSCs lines were maintained in feeder-free conditions and regularly tested for mycoplasma contamination. HiPSCs were differentiated into myeloid precursors (MPs) using a previously published protocol 79,80 . Briefly, HiPSCs were cultured for four days in embryoid body medium (containing ROCK inhibitor, BMP-4, SCF, and VEGF-121), and then cultured in hematopoietic medium (containing M-CSF and IL-3) for a maximum of 1.5 months, during which cells were harvested.…”

iSCORE-PD: an isogenic stem cell collection to research Parkinson’s Disease

“…Given these considerations, and the necessity for incorporating cells from both sexes, we opted to use the female hESC line WIBR3 of European descent (NIH approval number NIHhESC-10-0079). This cell line has been previously demonstrated to maintain a stable karyotype over prolonged in vitro culture and has been widely used to model human diseases including PD 29,31,[34][35][36][37][38][39][40] . For our effort, we acquired early passage WIBR3 cells (P19) and initially generated 3 independent single cell-derived subclones (WIBR3-S1, WIBR3-S2, WIBR3-S3).…”