Discovery of Active Ingredients Targeted TREM2 by SPR Biosensor-UPLC/MS Recognition System, and Investigating the Mechanism of Anti-Neuroinflammatory Activity on the Lignin-Amides from Datura metel Seeds.

Si-Yi Wang,Xiao-Mao Li,Hai-Xue Kuang,Hai Jiang,Bing-You Yang,Yan-Ping Sun,Yan Liu,Adnan Mohammed Algradi,Wei Guan,Juan Pan

doi:10.3390/molecules26195946

Abstract

As a new target protein for Alzheimer’s disease (AD), the triggering receptor expressed on myeloid Cells 2 (TREM2) was expressed on the surface of microglia, which was shown to regulate neuroinflammation, be associated with a variety of neuropathologic, and regarded as a potential indicator for monitoring AD. In this study, a novel recognition system based on surface plasmon resonance (SPR) for the TREM2 target spot was established coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-MS), in order to screen the active ingredients targeting TREM2 from Datura metel seeds. The results showed that four lignan-amides were discovered as candidate compounds by SPR biosensor-UPLC/MS recognition analysis. According to the guidance of the active ingredients discovered by the system, the lignin-amides from Datura metel seeds (LDS) were preliminarily identified as containing 27 lignan-amides, which were enriched compositions by the HP-20 of Datura metel seeds. Meanwhile, the anti-inflammatory activity of LDS was evaluated in BV2 microglia induced by LPS. Our experimental results demonstrated that LDS could reduce NO release in LPS-treated BV2 microglia cells and significantly reduce the expression of the proteins of inducible Nitric Oxide Synthase (iNOS), cyclooxygenase 2 (COX-2), microtubule-associated protein tau (Tau), and ionized calcium-binding adapter molecule 1 (IBA-1). Accordingly, LDS might increase the expression of TREM2/DNAX-activating protein of 12 kDa (DAP12) and suppress the Toll-like receptor SX4 (TLR4) pathway and Recombinant NLR Family, Pyrin Domain Containing Protein 3 (NLRP3)/cysteinyl aspartate specific proteinase-1 (Caspase-1) inflammasome expression by LDS in LPS-induced BV2 microglial cells. Then, the inhibitory release of inflammatory factors Interleukin 1 beta (IL-1β), Interleukin 6 (IL-6), and Tumor necrosis factor-alpha (TNFα) inflammatory cytokines were detected to inhibit neuroinflammatory responses. The present results propose that LDS has potential as an anti-neuroinflammatory agent against microglia-mediated neuroinflammatory disorders.

Highlights

Alzheimer’s disease (AD) is a progressive neurodegenerative disease with high incidence and severe economic burden
triggering receptor expressed on myeloid Cells 2 (TREM2) was diluted in 10 mM sodium acetate that was determined by a pre-coupling experiment and immobilized by the amine coupling method on a CM5 sensor chip according to the manual-injections protocol
The results indicated that the DPZ and lignin-amides from Datura metel seeds (LDS) could significantly inhibit NO production and down-regulate protein expression levels of inducible Nitric Oxide Synthase (iNOS) and cyclooxygenase 2 (COX-2), which suggested that LDS acted to reduce NO production by interfering with TREM2/Dap12 and Toll-like receptor SX4 (TLR4) pathways in LPS-stimulated BV2 microglia

Summary

Introduction

AD is a progressive neurodegenerative disease with high incidence and severe economic burden. The seeds of Datura metel had an intensive response signal in the SPR system targeted at TREM2, and four lignin-amides were identified that were regarded as TREM2 targeted active candidates by UPLC-MS analysis. The lignan-amides demonstrated outstanding effects for AD treatment involving acetylcholinesterase inhibitory activity, anti-oxidation, and anti-inflammatory in previous modern pharmacological studies [12,13,14,15,16]. The rich lignin-amides existed in the seeds of Datura metel including cannabisin D-H [17,18,19,20], and it possesses the traditional effects of the treatments of convulsion, epilepsy, and rheumatic arthralgia according to the Compendium of Materia Medica [3], together with analgesic, hypoglycemic, and anti-inflammation biological activities [21,22,23]. It should be noted that the underlying molecular mechanism remains unclear and needs further exploration, some studies have indicated the anti-neuroinflammatory potential of LDS

Methods

Results

Conclusion