A novel compound alleviates oxidative stress via PKA/CREB1-mediated DJ-1 upregulation.

Oxidative stress is one of the major culprits causing dopaminergic neuron loss in Parkinson's disease (PD). DJ-1 is a protein with multiple actions against oxidative stress, apoptosis, neuroinflammation, etc. DJ-1 expression is decreased in sporadic PD, therefore increasing DJ-1 expression might be beneficial in PD treatment. However, drugs known to upregulate DJ-1 are still lacking. In this study, we identified a novel DJ-1-elevating compound called ChemJ through luciferase assay-based high-throughput compound screening in SH-SY5Y cells and confirmed that ChemJ upregulated DJ-1 in SH-SY5Y cell line and primary cortical neurons. DJ-1 upregulation by ChemJ alleviated MPP+-induced oxidative stress. In exploring the underlying mechanisms, we found that the transcription factor CREB1 bound to DJ-1 promoter and positively regulated its expression under both unstressed and 1-methyl-4-phenylpyridinium-induced oxidative stress conditions and that ChemJ promoted DJ-1 expression via activating PKA/CREB1 pathway in SH-SY5Y cells. Our results demonstrated that ChemJ alleviated the MPP+-induced oxidative stress through a PKA/CREB1-mediated regulation of DJ-1 expression, thus offering a novel and promising avenue for PD treatment.

Organization of corticocortical and thalamocortical top-down inputs in the primary visual cortex.

Unified visual perception requires integration of bottom-up and top-down inputs in the primary visual cortex (V1), yet the organization of top-down inputs in V1 remains unclear. Here, we used optogenetics-assisted circuit mapping to identify how multiple top-down inputs from higher-order cortical and thalamic areas engage V1 excitatory and inhibitory neurons. Top-down inputs overlap in superficial layers yet segregate in deep layers. Inputs from the medial secondary visual cortex (V2M) and anterior cingulate cortex (ACA) converge on L6 Pyrs, whereas ventrolateral orbitofrontal cortex (ORBvl) and lateral posterior thalamic nucleus (LP) inputs are processed in parallel in Pyr-type-specific subnetworks (Pyr←ORBvl and Pyr←LP) and drive mutual inhibition between them via local interneurons. Our study deepens understanding of the top-down modulation mechanisms of visual processing and establishes that V2M and ACA inputs in L6 employ integrated processing distinct from the parallel processing of LP and ORBvl inputs in L5.