Table 1.
In vivo neuronal reprogramming in the spinal cord
| Cell source | Gene delivery method (timing) | Reprogramming factor | Efficiency (NeuN+) | Neuronal subtype | SCI model | Functional recovery | References |
|---|---|---|---|---|---|---|---|
| Neural progenitors | Retrovirus (0 dpi) | Ngn2 | 3%; 21.1% (+GFs); 28.2% (+GFs+BDNF) | GABAergic (major) | Complete transection (T10) | N/A | Ohori et al., 2006 |
| Astrocytes | Lentivirus (0 dpi) | Sox2 | 3%; 6% (+VPA) | Glutamatergic, GABAergic | Lateral hemisection (T7–T9) | N/A | Su et al., 2014 |
| Astrocytes | Lentivirus (0 dpi) | Sox2 + shRNA-p53 + BDNF-NOG | 20000* | Glutamatergic (major) | N/A | N/A | Wang et al., 2016 |
| Astrocytes | Lentivirus (0 dpi) | Sox2 + shRNA-p53 + BDNF-NOG | 6000* | N/A | Contusive injury (T7–T9) | N/A | Wang et al., 2016 |
| Astrocytes | Retrovirus (4 dpi), AAV (0 dpi) | NeuroD1 | 93.5–95% | Glutamatergic (major), GABAergic↑ by NeuroD1+Dlx2 | Stab injury (T11–T12) | N/A | Puls et al., 2020 |
| Astrocytes | AAV (10 dpi, 16 wpi) | NeuroD1 | > 95% | Glutamatergic | Contusive injury (T11–T12) | N/A | Puls et al., 2020 |
| NG2 glia | Lentivirus (0 dpi) | Sox2 | 5000; 44000 (+ BDNF-NOG); 84000 (+P75-2)* | Glutamatergic, GABAergic, glycinergic | N/A | N/A | Tai et al., 2021 |
| NG2 glia | Lentivirus (1 wpi) | SOX2 + p75-2 | 45.80% | N/A | Dorsal hemisection (C5) | Forelimb motor skill | Tai et al., 2021 |
AAV: Adeno-associated virus; BDNF: brain-derived neurotrophic factor; dpi: day(s) post injury; GFs: growth factors; NOG: noggin; N/A: not available; p75-2: a mutant form of the neurotrophic factor NT3; SCI: spinal cord injury; VPA: valproic acid; wpi: week(s) post injury; *: the number of neurons per injection.