Neurotherapeutics最新文献

Mitochondrial dysfunction is an important driver of neurodegeneration and synaptic abnormalities in Alzheimer's disease (AD). Amyloid beta (Aβ) in mitochondria leads to increased reactive oxygen species (ROS) production, resulting in a vicious cycle of oxidative stress in coordination with a defective electron transport chain (ETC), decreasing ATP production. AD neurons exhibit impaired mitochondrial dynamics, evidenced by fusion and fission imbalances, increased fragmentation, and deficient mitochondrial biogenesis, contributing to fewer mitochondria in brains of AD patients. Nuclear respiratory factor-1 (NRF1) is a regulator of mitochondrial biogenesis through its activation of mitochondrial transcription factor A (TFAM). Our hypothesis posited that NRF1 induction in neuronal cells exposed to amyloid β_1-42 (Aβ_1-42) would increase de novo mitochondrial synthesis and improve mitochondrial function, restoring neuronal survival. Following NRF1 messenger RNA (mRNA) transfection of Aβ_1-42-treated SH-SY5Y cells, a marked increase in mitochondrial mass was observed. Metabolic programming toward enhanced oxidative phosphorylation resulted in increased ATP production. Oxidative stress in the form of mitochondrial ROS accumulation was reduced and mitochondrial membrane potential preserved. Mitochondrial homeostasis was maintained, evidenced by balanced fusion and fission processes. Ultimately, improvement of mitochondrial function was associated with significant decreases in Aβ_1-42-induced neuronal death and neurite disruption. Our findings highlight the potential of NRF1 upregulation to counteract Aβ_1-42-associated mitochondrial dysfunction and neurodegenerative cell processes, opening avenues for innovative therapeutic approaches aimed at safeguarding mitochondrial health in AD neurons.

Tetrahydrobiopterin (BH4) expression is normally strictly controlled; however, its intracellular levels increase considerably following nerve damage. GTP cyclohydrolase I (GCH1) plays a crucial role in regulating BH4 concentration, with an upregulation observed in the dorsal root ganglion in cases of neuropathic pain. In this study, we aimed to develop and evaluate the clinical potential of an RNA interference-based adeno-associated virus (AAV) targeting GCH1 across various species to decrease BH4 levels and, consequently, alleviate neuropathic pain symptoms. We identified universal small-interfering RNA sequences effective across species and developed an AAV-u-shRNA that successfully suppressed GCH1 expression with minimal off-target effects. Male Sprague Dawley rats were divided into four groups: normal, spared nerve injury, AAV-shCON, and AAV-u-shGCH1. The rats were sacrificed on post-injection day 28 to collect blood for BH4 level assessment. The AAV-u-shGCH1 group demonstrated remarkable improvement in the mechanical withdrawal threshold by PID 28, significantly outperforming the normal, spared nerve injury, and AAV-shCON groups. Plasma BH4 levels confirmed that AAV-u-shGCH1 effectively reduced neuropathic pain by inhibiting BH4 synthesis in vivo, introducing a novel, multispecies-compatible therapeutic strategy. Our results suggest that a single application of AAV-u-shGCH1 could offer a viable solution for neuropathic pain relief.

Parkinson's disease (PD) is characterized by a progressive loss of dopaminergic neurons, linked to aggregation of alpha-synuclein (αSYN) into Lewy bodies. Current treatments are symptomatic and do not halt or reverse the neurodegeneration. Immunotherapy targeting aggregated αSYN shows potential, but therapeutic efficacy is limited by poor brain penetration of antibodies. We developed a bispecific antibody, RmAb38E2-scFv8D3, based on αSYN oligomer selective RmAb38E2 fused to a transferrin receptor (TfR)-binding domain to enhance brain delivery. Both RmAb38E2 and RmAb38E2-scFv8D3 showed higher affinity for αSYN oligomers than for monomers or fibrils. In vivo, RmAb38E2-scFv8D3 exhibited higher brain and lower blood concentrations compared to RmAb38E2, suggesting a better brain uptake and reduced peripheral exposure for the bispecific antibody. Treatment over five days of 3-4 months old transgenic L61 mice, which overexpress human αSYN, with three doses of RmAb38E2-scFv8D3 reduced brain αSYN oligomer levels and increased microglial activation, as indicated by elevated soluble TREM2 levels. Treatment with the monospecific RmAb38E2, however, showed no significant effect compared to PBS. This study demonstrates that TfR-mediated delivery enhances the therapeutic potential of αSYN-targeted immunotherapy by resulting in a higher concentration and a more uniform distribution of antibodies in the brain. The use of bispecific antibodies offers a promising strategy to improve the efficacy of antibody therapies in PD and other α-synucleinopathies.

Molecules with optimized pharmacokinetic properties selectively aimed at the inhibition of STAT3 phosphorylation in brain have recently emerged as potential disease modifying therapies for epilepsy. In the current study, pharmacological inhibition of JAK1/2 with the orally available, FDA-approved drug ruxolitinib, produced nearly complete inhibition of hippocampal STAT3 phosphorylation, and reduced the expression of its downstream target Cyclin D1, when administered to rats 30 ​min and 3 ​h after onset of pilocarpine-induced status epilepticus (SE). This effect was accompanied by significantly shorter seizure duration and lower overall seizure frequency throughout the 4 weeks of EEG recording, but did not completely prevent the development of epilepsy in ruxolitinib-treated male rats. Compared to DMSO-treated animals, administration of ruxolitinib also improved memory (Y maze) but did not impact motor function (open field) following SE. Taken together with our previous findings, the results of this study provide further evidence that inhibition of the JAK/STAT pathway may be a promising disease modifying strategy to reduce severity of acquired epilepsy after brain injury, but also point to the need to better understand and optimize inhibitors of this pathway.