Synthesis of some new acylhydrazone compounds containing the 1,2,4-triazole structure and their neuritogenic activities in Neuro-2a cells

Acylhydrazone Derivative A5 Promotes Neurogenesis by Up-Regulating Neurogenesis-Related Genes and Inhibiting Cell-Cycle Progression in Neural Stem/Progenitor Cells

Adult neurogenesis involves the generation of functional neurons from neural progenitor cells, which have the potential to complement and restore damaged neurons and neural circuits. Therefore, the development of drugs that stimulate neurogenesis represents a promising strategy in stem cell therapy and neural regeneration, greatly facilitating the reconstruction of neural circuits in cases of neurodegeneration and brain injury. Our study reveals that compound A5, previously designed and synthesized by our team, exhibits remarkable neuritogenic activities, effectively inducing neurogenesis in neural stem/progenitor cells (NSPCs). Subsequently, transcriptome analysis using high-throughput Illumina RNA-seq technology was performed to further elucidate the underlying molecular mechanisms by which Compound A5 promotes neurogenesis. Notably, comparative transcriptome analysis showed that the up-regulated genes were mainly associated with neurogenesis, and the down-regulated genes were mainly concerned with cell cycle progression. Furthermore, we confirmed that Compound A5 significantly affected the expression of transcription factors related to neurogenesis and cell cycle regulatory proteins. Collectively, these findings identify a new compound with neurogenic activity and may provide insights into drug discovery for neural repair and regeneration.

Poria cocos (Schw.) Wolf, a Traditional Chinese Edible Medicinal Herb, Promotes Neuronal Differentiation, and the Morphological Maturation of Newborn Neurons in Neural Stem/Progenitor Cells

Neurogenesis in the adult brain comprises the entire set of events of neuronal development. It begins with the division of precursor cells to form a mature, integrated, and functioning neuronal network. Adult neurogenesis is believed to play an important role in animals' cognitive abilities, including learning and memory. In the present study, significant neuronal differentiation-promoting activity of 80% (v/v) ethanol extract of P. cocos (EEPC) was found in Neuro-2a cells and mouse cortical neural stem/progenitor cells (NSPCs). Subsequently, a total of 97 compounds in EEPC were identified by UHPLC-Q-Exactive-MS/MS. Among them, four major compounds-Adenosine; Choline; Ethyl palmitoleate; and L-(-)-arabinitol-were further studied for their neuronal differentiation-promoting activity. Of which, choline has the most significant neuronal differentiation-promoting activity, indicating that choline, as the main bioactive compound in P. cocos, may have a positive effect on learning and memory functions. Compared with similar research literature, this is the first time that the neuronal differentiation-promoting effects of P. cocos extract have been studied.

Pancreatic cancer cell-derived semaphorin 3A promotes neuron recruitment to accelerate tumor growth and dissemination

Perineural invasion and neurogenesis are frequently observed in pancreatic ductal adenocarcinoma (PDAC), and they are associated with a poor prognosis. Axon guidance factor semaphorin 3A (SEMA3A) is upregulated in PDAC. However, it remains unclear whether cancer-derived SEMA3A influences nerve innervation and pancreatic tumorigenesis. In silico analyses were performed using PROGgene and NetworkAnalyst to clarify the importance of SEMA3A and its receptors, plexin A1 (PLXNA1) and neuropilin 2 (NRP2), in pancreatic cancer. In vitro assays, including migration, neurite outgrowth, and 3D recruitment, were performed to study the effects of SEMA3A on neuronal behaviors. Additionally, an orthotopic animal study using C57BL/6 mice was performed to validate the in vitro findings. Expression of SEMA3A and its receptors predicted worse prognosis for PDAC. Cancer-derived SEMA3A promoted neural migration, neurite outgrowth, and neural recruitment. Furthermore, SEMA3A-induced effects depended on PLXNA1, NRP2, and MAPK activation. Trametinib, an approved MAPK kinase (MEK) inhibitor, counteracted SEMA3A-enhanced neuronal activity in vitro. Inhibition of SEMA3A by shRNA in pancreatic cancer cells resulted in decreased neural recruitment, tumor growth, and dissemination in vivo. Our results suggested that cancer-secreted SEMA3A plays an important role in promoting neo-neurogenesis and progression of PDAC.

Discovery of Neuroprotective Agents Based on a 5-(4-Pyridinyl)-1,2,4-triazole Scaffold

Parkinson's disease (PD) is characterized by the death of dopaminergic neurons. The common histopathological hallmark in PD patients is the formation of intracellular proteinaceous accumulations. The main constituent of these inclusions is alpha-synuclein (α-syn), an intrinsically disordered protein that in pathological conditions creates amyloid aggregates that lead to neurotoxicity and neurodegeneration. The main goal of our study was to optimize our previously identified α-syn aggregation inhibitors of 5-(4-pyridinyl)-1,2,4-triazole chemotype in terms of in vivo efficacy. Our efforts resulted in the identification of ethyl 2-((4-amino-5-(pyridin-4-yl)-4H-1,2,4-triazol-3-yl)thio)acetate (15), which displayed the ability to prevent 1-methyl-4-phenyl-1,2,3,6-tetrahydropiridine-induced bradykinesia as well as to affect the levels of PD markers after the administration of the same neurotoxin. In addition to the in vivo evaluation, for the 5-(4-pyridinyl)-1,2,4-triazole-based compounds, we measured the prevention of the fibrillization process using light scattering and a ThT binding assay; these compounds have been shown to slightly reduce the α-syn aggregation.