Fingolimod loaded niosomes attenuates sevoflurane induced cognitive impairments

The S1P receptor 1 antagonist Ponesimod reduces TLR4-induced neuroinflammation and increases Aβ clearance in 5XFAD mice

BACKGROUND

Previously, we showed that the sphingosine-1-phosphate (S1P) transporter spinster 2 (Spns2) mediates activation of microglia in response to amyloid β peptide (Aβ). Here, we investigated if Ponesimod, a functional S1P receptor 1 (S1PR1) antagonist, prevents Aβ-induced activation of glial cells and Alzheimer's disease (AD) pathology.

METHODS

We used primary cultures of glial cells and the 5XFAD mouse model to determine the effect of Aβ and Ponesimod on glial activation, Aβ phagocytosis, cytokine levels and pro-inflammatory signaling pathways, AD pathology, and cognitive performance.

FINDINGS

Aβ42 increased the levels of TLR4 and S1PR1, leading to their complex formation. Ponesimod prevented the increase in TLR4 and S1PR1 levels, as well as the formation of their complex. It also reduced the activation of the pro-inflammatory Stat1 and p38 MAPK signaling pathways, while activating the anti-inflammatory Stat6 pathway. This was consistent with increased phagocytosis of Aβ42 in primary cultured microglia. In 5XFAD mice, Ponesimod decreased the levels of TNF-α and CXCL10, which activate TLR4 and Stat1. It also increased the level of IL-33, an anti-inflammatory cytokine that promotes Aβ42 phagocytosis by microglia. As a result of these changes, Ponesimod decreased the number of Iba-1+ microglia and GFAP+ astrocytes, and the size and number of amyloid plaques, while improving spatial memory as measured in a Y-maze test.

INTERPRETATION

Ponesimod targeting S1PR1 is a promising therapeutic approach to reprogram microglia, reduce neuroinflammation, and increase Aβ clearance in AD.

FUNDING

NIHR01AG064234, RF1AG078338, R21AG078601, VAI01BX003643.

A state-of-the-art review on the recent advances of niosomes as a targeted drug delivery system

The buildup of nonionic surfactants in the aqueous environment produces niosomes. The usage of niosomes is becoming increasingly frequent due to their sustainability, low cost of components and assembly, large-scale manufacture, and, finally, easy maintenance of the niosomes to the other. Because of their nonionic characteristics, niosomes play a critical role in medication delivery systems. Controlled release and targeted distribution of niosomes to treat cancer, infectious illnesses, and other disorders are one of their most important properties. Niosomes can also be injected by ocular and transdermal routes, which are less common than oral and parenteral administration. Using niosomes to manufacture biotechnology goods and novel vaccines is one of the most exciting research fields today. The molecular structure of niosomes, the physicochemical characteristics of nonionic surfactants in their formulation, the influence of external stimuli on niosomes, the many methods of niosomes administration, and their diverse therapeutic qualities are all explored in this study.