Lactoferrin Attenuates Pro-Inflammatory Response and Promotes the Conversion into Neuronal Lineages in the Astrocytes

Abstract

Neurodegenerative diseases are characterized by progressive loss of neurons and persistent inflammation. Neurons are terminally differentiated cells, and lost neurons cannot be replaced since neurogenesis is restricted to only two neurogenic niches in the adult brain, whose neurogenic potential decreases with age. In this regard, the astrocytes reprogramming into neurons may represent a promising strategy for restoring the lost neurons and rebuilding neural circuits. To date, many anti-inflammatory agents have been shown to reduce neuroinflammation; however, their potential to restore neuronal loss was poorly investigated. This study investigates the anti-inflammatory effects of lactoferrin on DI-TNC1 astrocyte cell line and its ability to induce astrocyte reprogramming in a context of sustained inflammation. For this purpose, astrocytes were pre-treated with lactoferrin (4 μg/mL) for 24 h, then with lipopolysaccharide (LPS) (400 ng/mL), and examined 2, 9 and 16 days from treatment. The results demonstrate that lactoferrin attenuates astrocyte reactivity by reducing Toll-like receptor 4 (TLR4), Glial fibrillary acidic protein (GFAP) and IL-6 expression, as well as by upregulating Interleukin-10 (IL-10) cytokine and NRF2 expression. Moreover, lactoferrin promotes the reprogramming of reactive astrocytes into proliferative neuroblasts by inducing the overexpression of the Sex determining region Y/SRY-box 2 (SOX2) reprogramming transcription factor. Overall, this study highlights the potential effects of lactoferrin to attenuate neuroinflammation and improve neurogenesis, suggesting a future strategy for the treatment of neurodegenerative disorders.