Effects of interleukin-1β on the plasticity of differentiated neurons from the human neuroblastoma lineage SH-SY5Y

Author(s)

Anísia Sofia Mota Barros

• Document type: Master's Dissertation
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina de Ribeirão Preto (PCARP/BC)
• Defense date: 2024-04-03

Examining board members

Sabrina Francesca de Souza Lisboa; Luciana Politti Cartarozzi

• Advisor: Sabrina Francesca de Souza Lisboa

Abstract

Neuroinflammation is an inflammatory process that occurs in the Central Nervous System (CNS) when exposed to aggressive stimuli. Although it involves a protective pathway, the effect generated can be toxic, since neuroinflammation involves the activation of microglia, which can lead to increased release of a series of neurotoxic compounds, such as Interleukin-1β (IL-1β). When at high levels and in chronic cases of neuroinflammation, such interleukin becomes excitotoxic. In this sense, the Endocannabinoid System (ECS) can act as an important neuroprotective entity, capable of preventing or delaying neuronal loss caused by IL-1β. Previous studies carried out in animal models demonstrate that IL1β can affect components of the SECB and neuroplasticity, highlighting the importance of understanding the effects of this cytokine in human cellular models. From this, the effects of IL-1β (0.01, 0.1, 1, 10 ng/mL) on neuroplasticity and our SECB components in cells of the SH-SY5Y lineage differentiated into a mature neuronal phenotype were investigated. Data obtained through standardization of the differentiation protocol of SHSY5Y cells into mature neurons revealed that 8-day cell differentiation with retinoic acid (RA, 10 µm) and brain-derived neurotrophic factor (BDNF, 50 ng/mL) caused morphological changes, leading to the appearance of an elongated appearance of neurons and large neuritic extensions. Furthermore, the differentiation process led to a greater expression of βIII-tubulin, D1 receptor and Neuronal Nuclei (NeuN), as well as the differentiated cells becoming more sensitive to an inflammatory stimulus lipopolysaccharide (LPS, 1, 10, 20, 40, 80, 160, 320 and 640 µg/mL). The differentiated cells did not show changes in the expression of N-methyl D-aspartate (NMDAR1) and Tyrosine Hydroxylase (TH). Still, exposure of differentiated neurons to IL-1β did not alter cellular choices. In differentiated cells, after application of different concentrations of IL-1β, there were no changes in the expression of total Tyrosine Kinase B (TrKB) and an increase profile was presented in the expression of synaptophysin after application of 0.01, 1 and 10 ng/mL of IL-1β. Furthermore, the different concentrations of IL-1β did not modify the expression of βIII-tubulin and the number of cells. Furthermore, there was a reduction in the length of primary neurites after application of 10 ng/mL of IL-1β. A reduction in actin expression was also observed after application of IL-1β (0.1 and 10 ng/mL) to the cells. Furthermore, treatment with IL-1β (1 and 10 ng/mL) led to a significant increase in the expression of the CB1 receptor, just as 0.1 ng/mL of interleukin led to a reduction in the expression of the potential vanilloid receptor transient type 1 (TRPV1). Treatment with 0.1, 1 and 10 ng/mL of IL-1β led to a reduction in the expression of fatty acid amide hydrolase (FAAH) and the application of 0.01, 0.1 and 1 ng/mL of interleukin prevented the expression of monoacylglycerol lipase (MAGL). Our results suggest that the IL-1β concentrations used may be affecting a possible neuroprotection mechanism involving SECB. Therefore, further investigations should be carried out to better understand the effects of IL-1β. (AU)

• FAPESP's process: 22/10801-0 - Investigation of the effects of IL-1B on neuroplasticity and the Endocannabinoid System of hippocampal neurons
• Grantee: Anísia Sofia Mota Barros
• Support Opportunities: Scholarships in Brazil - Master