LPS-Induced Neuroinflammation Disrupts Brain-Derived Neurotrophic Factor and Kinase Pathways in Alzheimer's Disease Cell Models

Alzheimer's disease (AD) leads to a progressive loss of cognitive abilities and memory. A critical factor now recognized as driving AD pathology is neuroinflammation-inflammation occurring in the nervous system, which contributes to neuronal harm and communication breakdowns. our research investigated the specific effects of neuroinflammation on neuronal signaling pathways. In this study, we primarily employed the SH-SY5Y neuroblastoma cell line as an in vitro neuronal model to investigate inflammatory responses relevant to AD etiology, alongside supplementary observations in primary neurons and 3D spheroids for comparative analysis. Our analysis focused on modifications of key molecules, including the neuroprotective protein Brain-Derived Neurotrophic Factor (BDNF), pro-inflammatory cytokines such as IL-6 and TNF-α, and crucial regulatory kinases. Our results demonstrated that LPS treatment dramatically lowered the vitality and decreased BDNF levels in the SH-SY5Y cells. Furthermore, we observed a considerable elevation in the pro-inflammatory cytokines IL-6 and TNF-α, coupled with elevated levels of COX-2 and iNOS. Gene expression data validated that LPS treatment altered the expression of essential signaling kinases (Protein Kinase A (PKA), Protein Kinase B (AKT), and Mitogen-Activated Protein Kinase (MAPK)). Our first comparative analysis revealed that 3D spheroid cultures may elicit more pronounced inflammatory responses than standard 2D cultures; nevertheless, our detailed investigation primarily focused on the SH-SY5Y model. This study revealed that LPS-induced neuroinflammation affects neuronal signaling in vitro, thereby revealing a relationship between inflammation and neuronal dysfunction in cellular models of neuroinflammation. These findings highlight pathways that may be relevant to AD pathophysiology; however, further in vivo studies are necessary to demonstrate their translational relevance to humans.