Foxa1andFoxa2regulate multiple phases of midbrain dopaminergic neuron development in a dosage-dependent manner

Abstract

The role of transcription factors in regulating the development of midbrain dopaminergic (mDA) neurons is intensively studied owing to the involvement of these neurons in diverse neurological disorders. Here we demonstrate novel roles for the forkhead/winged helix transcription factors Foxa1 and Foxa2 in the specification and differentiation of mDA neurons by analysing the phenotype of Foxa1 and Foxa2 single-and double-mutant mouse embryos. During specification, Foxa1 and Foxa2 regulate the extent of neurogenesis in mDA progenitors by positively regulating Ngn2 (Neurog2) expression. Subsequently, Foxa1 and Foxa2 regulate the expression of Nurr1 (Nr4a2) and engrailed 1 in immature neurons and the expression of aromatic L-amino acid decarboxylase and tyrosine hydroxylase in mature neurons during early and late differentiation of midbrain dopaminergic neurons. Interestingly, genetic evidence indicates that these functions require different gene dosages of Foxa1 and Foxa2. Altogether, our results demonstrate that Foxa1 and Foxa2 regulate multiple phases of midbrain dopaminergic neuron development in a dosagedependent manner.

Autologous mesenchymal stem cell–derived dopaminergic neurons function in parkinsonian macaques

“…When control tissues obtained from a cynomolgus embryo and an adult animal were analyzed, both showed that the substantia nigra pars compacta (SNc) was strongly positive for GIRK2 and FOXA2 and weakly positive for calbindin, while the ventral tegmental area (VTA) was weakly positive for GIRK2 and FOXA2 but strongly positive for calbindin ( Figure 1J). This distinct pattern of GIRK2/FOXA2/calbindin expression in the SNc and VTA is consistent with those reported in other species, including rodents and humans (15,28,29). We also evaluated the induction efficiency of MSC-DP cells by quantitative immunocytochemistry.…”

“…This report further characterized the MSC-DP cells and found that they were double positive for FOXA2 and GIRK2, both specific markers of differentiated A9 dopaminergic neurons. In particular, FOXA2 was recently identified as a transcription factor required for specifying and maintaining the dopaminergic neuron phenotype (28,42) and is considered to be expressed exclusively in floor plate-derived dopaminergic neurons (43). We confirmed the coexpression of FOXA2 and GIRK2 in SNc tissue that contains A9 dopaminergic neurons but not in the VTA, which contains A10 dopaminergic neurons.…”

“…We analyzed the relative expression levels of GIRK2, FOXA2, and CALB1 mRNAs using RT-PCR to classify MSC-DP cells as A9-type neurons (GIRK2 + /FOXA2 + /CALB1 − ) or A10-type neurons (GIRK2 − /FOXA2 − /CALB1 + ) (28,29,56). The amount of cDNA was normalized on the basis of the signal from the ubiquitously expressed β-actin.…”

“…The MSC-DP cells, prepared autologously from the bone marrow of each test animal, expressed cell makers not only for antigens that have been previously described (20,21), such as β tubulin III (Tuj1), microtubule-associated protein 2 (MAP-2), TH, and DAT, but also for those specific to the A9 subtype, namely, G protein-coupled inward rectifying current potassium channel type 2 (GIRK2) (15) and forkhead box protein A2 (FOXA2) (28). The effect of transplantation was evaluated for up to 9 months based on motor behaviors of affected hand movements; PET scans using 11 C-CFT, which specifically labels DAT; and postmortem histology.…”

Differentiated Parkinson patient-derived induced pluripotent stem cells grow in the adult rodent brain and reduce motor asymmetry in Parkinsonian rats

“…However, only a few graft-derived DA axons were found to innervate the host striatum, indicating a heterogenous population of engrafted Girk-2-and TH-coexpressing DA neurons. Indeed, a subset of other neurons outside the A9 region also coexpress TH and Girk-2 (26) and the engrafted PDiPS cellderived DA neurons did not coexpress the transcription factor foxA2 that is found together with TH in most A9 midbrain DA neurons (27). Therefore, we believe the PDiPS cells have most likely been inefficiently patterned toward an A9 DA neuronal phenotype during in vitro differentiation.…”