Neurons in the CNS lose regenerative potential with maturity, leading to minimal corticospinal tract (CST) axon regrowth after spinal cord injury (SCI). In young rodents, knockdown of PTEN, which antagonizes PI3K signaling by hydrolyzing PIP3, promotes axon regeneration following SCI. However, this effect diminishes in adults, potentially due to lower PI3K activation leading to reduced PIP3. This study explores whether increased PIP3 generation can promote long-distance regeneration in adults. We used a hyperactive PI3K, PI3Kδ (PIK3CD), to boost PIP3 levels in mature cortical neurons and assessed CST regeneration after SCI. Adult rats received AAV1-PIK3CD and AAV1-eGFP, or AAV1-eGFP alone, in the sensorimotor cortex concurrent with a C4 dorsal SCI. Transduced neurons showed increased pS6 levels, indicating elevated PI3K/Akt/mTOR signaling. CST regeneration, confirmed with retrograde tracing, was evaluated up to 16 weeks post injury. At 12 weeks, ∼100 axons were present at lesion sites, doubling to 200 by 16 weeks, with regeneration indices of 0.1 and 0.2, respectively. Behavioral tests showed significant improvements in paw reaching, grip strength, and ladder-rung walking in PIK3CD-treated rats, corroborated by electrophysiological recordings of cord dorsum potentials and distal flexor muscle electromyography. Thus, PI3Kδ upregulation in adult cortical neurons enhances axonal regeneration and functional recovery post SCI.
- Klíčová slova
- CST, PI3K, axon regeneration, c-Fos, electrophysiology, pS6, signaling, skilled paw reaching, spinal cord, spinal cord injury,
- MeSH
- axony metabolismus fyziologie MeSH
- Dependovirus genetika MeSH
- fosfatidylinositol-3-kinasy třídy I metabolismus genetika MeSH
- fosfatidylinositol-3-kinasy metabolismus MeSH
- genetické vektory genetika MeSH
- krysa rodu Rattus MeSH
- modely nemocí na zvířatech MeSH
- neurony metabolismus MeSH
- obnova funkce MeSH
- poranění míchy * metabolismus terapie genetika MeSH
- pyramidové dráhy * metabolismus MeSH
- regenerace nervu * MeSH
- signální transdukce MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- fosfatidylinositol-3-kinasy třídy I MeSH
- fosfatidylinositol-3-kinasy MeSH
BACKGROUND: TDP-43 proteinopathies represent a spectrum of neurodegenerative disorders. Variable clinical presentations including frontotemporal dementia, amyotrophic lateral sclerosis (ALS) and mixed forms are associated with the spatial heterogeneity of the TDP-43 pathology. Recent studies have emphasized the role of oligodendrocytes in the pathogenesis of ALS. OBJECTIVE: To evaluate whether TDP-43 proteinopathies are associated with an oligodendroglial response. METHODS: We performed a study on 7 controls and 10 diseased patients with spinal cord involvement. Using the oligodendroglia-specific antibody TPPP/p25, we assessed oligodendrocyte density in the lateral corticospinal tracts (LCSs) along with the presence of perineuronal oligodendrocytes (PNOGs) in the anterior horns. We performed a densitometry of myelin basic protein (MBP) immunoreactivity. The numbers of TDP-43 and p62 immunoreactive inclusions were counted in both the LCSs and the anterior horns. RESULTS: Double immunolabeling confirmed that oligodendrocytes harbor TDP-43 inclusions. In the LCSs, MBP density, but not the number of oligodendrocytes, was decreased in the diseased group. However, oligodendrocyte counts in the LCS correlated positively, and the density of MBP inversely, with the number of neuronal inclusions in the anterior horn, suggestive of a compensatory response of oligodendrocytes. The number of neurons with PNOGs correlated with the amount of inclusions. CONCLUSION: Our study further emphasizes the importance of oligodendroglia in the pathogenesis of TDP-43 proteinopathies with spinal cord involvement.
- MeSH
- buněčná inkluze metabolismus patologie MeSH
- buňky předních rohů míšních metabolismus patologie MeSH
- DNA vazebné proteiny metabolismus MeSH
- dospělí MeSH
- encefalitogenní základní proteiny metabolismus MeSH
- lidé středního věku MeSH
- lidé MeSH
- mícha metabolismus patologie MeSH
- mladý dospělý MeSH
- motorické neurony metabolismus patologie MeSH
- oligodendroglie metabolismus patologie MeSH
- proteinopatie TDP-43 metabolismus patologie MeSH
- proteiny vázající RNA metabolismus MeSH
- pyramidové dráhy metabolismus patologie MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- DNA vazebné proteiny MeSH
- encefalitogenní základní proteiny MeSH
- MBP protein, human MeSH Prohlížeč
- P62 protein, human MeSH Prohlížeč
- proteiny vázající RNA MeSH
- TARDBP protein, human MeSH Prohlížeč
- MeSH
- chemická stimulace MeSH
- daktinomycin farmakologie MeSH
- guanin farmakologie MeSH
- hořčík MeSH
- hypothalamus metabolismus MeSH
- interneurony metabolismus MeSH
- krysa rodu Rattus MeSH
- lidé MeSH
- mozek metabolismus MeSH
- neurony metabolismus MeSH
- paměť * MeSH
- pemolin farmakologie MeSH
- Purkyňovy buňky metabolismus MeSH
- pyramidové dráhy metabolismus MeSH
- RNA antagonisté a inhibitory biosyntéza MeSH
- Turbellaria MeSH
- učení * MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- daktinomycin MeSH
- guanin MeSH
- hořčík MeSH
- pemolin MeSH
- RNA MeSH