Table 1.
List of genome editing strategies in CNS cells.
| Editing strategy | Targeted gene | Delivery platform | Animal/cell models | Administration route |
Editing efficiency (total nr of edited cells) |
Edited cells (proportions of different cell types) | References | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Neurons | Astro | OLs | Müller | Microglia | |||||||
| NHEJ-mediated gene disruption | SOD1 | AAV9-SaCas9 | SOD1G93A mice (neonatal) | ICV | ++ | na | Duan et al., 2020 | ||||
| Ddit3 and Sarm1 | AAV2-SpCas9 | C57BL/6 WT mice (3/8-week-old) | Intravitreal | ~11% (Ddit3) ~94% (Sarm1) |
~11% (Ddit3) ~94% (Sarm1) |
na | na | na | na | Wang et al., 2020a | |
| HTT, GFP and SpCas9 (self-inactivating system) | LV-KamiSpCas9 | HD hiPSC-derived neurons and glia | 58% (HTT) >90% (SpCas9) |
+++ | +++ | na | na | na | Merienne et al., 2017 | ||
| LV-CRISPR | Murine striatal neurons | 50% (GFP) | 100% | ||||||||
| LV-CRISPR | Murine striatal astrocytes | 15% (GFP) | 100% | ||||||||
| LV-KamiSpCas9 | Ki140CAG mice (10-week-old) | IP (striatum) | ~60% (HTT) >90% (SpCas9) |
na | |||||||
| GABAα | IDLV-α2/SpCas9 | Murine cortical neurons | ++ | 100% | Ortinski et al., 2017 | ||||||
| Sprague-Dawley rats (adult) | IP (NaC) | +++ in NaC | +++ | na | na | na | na | ||||
| APP | AVV9-SaCas9 | hiPSC-derived neurons (APP V717I mutation) | +++ | 100% | Sun et al., 2019 | ||||||
| C57BL/6 WT mice (8-week-old) | IP (hip) ICV |
+++ | +++ | na | na | na | na | ||||
| YFP | CRISPR-Gold (RNP-Cas9) | Thy1-YFP mice (4/8-week-old) | IP (hip) | 17–34% | +++ | na | na | na | na | Lee et al., 2018 | |
| CRISPR-Gold (RNP-Cpf1) | 25–28% | +++ | na | na | na | na | |||||
| dTomato | CRISPR-Gold (RNP-Cas9) | Ai9 mice (4/8-week-old) | IP (hip) | 10% in hip | 10% | 50% | na | na | 40% | ||
| IP (striatum) | 15% in striatum | 10% | 50% | na | na | 40% | |||||
| CRISPR-Gold (RNP-Cpf1) | IP (hip) | 15% in hip | 10% | 50% | na | na | 40% | ||||
| IP (striatum) | 15% in striatum | 10% | 50% | na | na | 40% | |||||
| mGluR5 | CRISPR-Gold (RNP-Cas9) | FMR1 knock-out mice (4/8-week-old) | IP (striatum) | ~42% of mGluR+ cells | +++ | na | na | na | na | ||
| dTomato | RNP (4xNLS-Cas9–2xNLS) | dTomato mice (15/20-week-old) | IP (S1) | 100 dTomato+ cells/pmol RNP | +++ | + | na | na | na | Staahl et al., 2017 | |
| IP (striatum) | 150 dTomato+ cells/pmol RNP | ||||||||||
| IP (hip) | 100 dTomato+ cells/pmol RNP | ||||||||||
| IP (V1) | ~70 dTomato+ cells/pmol RNP | ||||||||||
| eGFP | Cas9 NCs | Tau-eGFP mice (8-week-old) | IP (cer cx) | ~50% of eGFP+ cells | +++ | na | na | na | na | Park et al., 2019 | |
| Pitx3-eGFP (8-week-old) | IP (midbrain) | ~60% of eGFP+ cells | |||||||||
| Th1 | C57BL6/J WT mice (8-week-old) |
IP (hip) | ~70% of Th1+ cells | ||||||||
| Bace1 | C57BL6/J WT mice (8-week-old) |
IP (midbrain) | ~70% of Bace1+ cells | ||||||||
| Bace1 | 5xFAD mice (6-week-old) | IP (hip) | 70% reduction of Bace1 expression | na | |||||||
| HIV-1 proviral LTR |
AAV9P1 | hNSC-derived latGFP1.2 astrocytes/neurons | ~5-fold reduction of HIV-1 transcripts | + | +++ | na | na | na | Kunze et al., 2018 | ||
| Sox9 | LV.SpCas9-sgRNA | Müller cells isolated from neonatal Sprague–Dawley rats. | 80% | 100% | Wang et al., 2018a | ||||||
| Mertk | AAV-SaCas9 | Sprague–Dawley rats | Intravitreal | +++ | na | na | na | +++ | na | Koh et al., 2018 | |
| Targeted integration (HDR or HMEJ pathway) |
Insertion of mCherry sequence at different genomic loci | AAV9-spCas9 | murine astrocytes | HDR: ~1% | 100% | Yao et al., 2017 | |||||
| HMEJ: ~2% | |||||||||||
| murine neurons | HDR: ~0.5% | 100% | |||||||||
| HMEJ: ~2% | |||||||||||
| C57BL/6 WT mice (8-week-old) | IP (cortex) | HDR: ~5% | +++ | na | na | na | na | ||||
| HMEJ: 52.8% ± 11.3 | |||||||||||
| C57BL/6 WT mice (E14.5) | In utero electroporation | HDR: ~1% | +++ | na | na | na | na | ||||
| HMEJ: 10.0% ± 0.7 | |||||||||||
| Base editors | Dnmt1 | v5 AAV-CBE or v5 AAV-ABE | C57BL/6 WT mice (neonatal) | ICV | CBE: 2.5–50% | +++ | na | na | na | na | Levy et al., 2020 |
| ABE: 1.3–43% | |||||||||||
| C57BL/6 WT mice (2-week-old) | IV | CBE: 35–59% | +++ | na | + | na | na | ||||
| Npc1 (c.3182T>C mutation) | Npc1 I1061T (c.3182T>C) mice (neonatal) | ICV | CBE: 0.4% ± 0.51 to 48% ± 8.2 | +++ | na | na | na | na | |||
| Epigenome editors |
pSyn1-iRFP720-GFP | AAV1-PHP.B-dCas9 | C57BL/6 WT mice | IV | 350–450% increased fluorescence intensity (ventral brain) | +++ | na | na | na | na | Lau et al., 2019 |
| Scn1a | AAV-PHP.eB-sgRNA | floxed-dCas9-VPRVPR/+/Vgat-CreCre/+/Scn1aRX/+ mice | IV | 2/3-fold increased expression of Scn1a (in OB, striatum and neocortex) | +++ | na | na | na | na | Yamagata et al., 2020 | |
In the table are reported the more relevant in vitro and in vivo studies evaluating the editing efficiency upon delivery of Cas9 nucleases (NHEJ, HDR, and HMEJ pathways), base editors (CBEs and ABEs) and epigenome editors in neurons and/or glia cells (Astro, astrocytes; OLs, oligodendrocytes; Müller, müller glia cells; Microglia). Editing efficiency is indicated as downregulation/upregulation of target genes or percentage of edited cells. When quantitative data were not available, a qualitative score (+++, many cells; +, few cells; na, not assessed) based on immunofluorescent analyses is reported in the table. ICV, intracerebroventricular; IP, intraparenchymal; IV, intravenous; NaC, nucleus accumbens; GL, granular layer; ML, molecular layer; Hip, hippocampus; V1, visual cortex; S1, somatosensory cortex; OB, olfactory bulb; LV, lentiviral vector; AAV, adeno-associated vector.