scholarly journals Structural Architectural Features of Cyclodextrin Oligoesters Revealed by Fragmentation Mass Spectrometry Analysis

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2259 ◽  
Author(s):  
Cristian Peptu ◽  
Maksym Danchenko ◽  
Ľudovít Škultéty ◽  
Jaroslav Mosnáček

Cyclodextrins (CDs) were used in the present study for the ring-opening oligomerization (ROO) of l-lactide (LA) in order to synthesize biodegradable products with possible applications in pharmaceutical and medical fields. The practical importance of ROO reactions may reside in the possibility of synthesizing novel CD derivatives with high purity due to the dual role played by CDs, the role of the initiator through the hydroxylic groups, and the role of the catalyst by monomer inclusion in the CD cavity. The analyzed compounds were CDs modified with oligolactides obtained through ROO reactions of l-lactide in dimethylformamide. The resulting CD isomeric mixtures were investigated using classical characterization techniques such as gel permeation chromatography and nuclear magnetic resonance. Moreover, advanced mass spectrometry (MS) techniques were employed for the determination of the average number of monomer units attached to the cyclodextrin and the architecture of the derivatives (if the monomer units were attached as a single chain or as multiple chains). Thus, fragmentation studies effectuated on two different instruments (ESI Q-TOF and MALDI TOF) allowed us to correlate the size of the oligolactide chains attached to the CD with the observed fragmentation patterns.

2020 ◽  
Author(s):  
Utpal Kumar Adhikari ◽  
Elif Sakiz ◽  
Umma Habiba ◽  
Sachin Kumar ◽  
Meena Mikhael ◽  
...  

Abstract Background: Previous reports identified proteins associated with ‘apoptosis’ following cross-linking PrPC with motif-specific anti-PrP antibodies in vivo and in vitro. The molecular mechanisms underlying this IgG-mediated neurotoxicity and the role of the activated proteins in the apoptotic pathways leading to neuronal death has not been properly defined. Previous reports implicated a number of proteins, including apolipoprotein E, cytoplasmic phospholipase A2, prostaglandin and calpain with anti-PrP antibody-mediated ‘apoptosis’, however, these proteins are also known to play an important role in allergy. In this study, we investigated whether cross-linking PrPC with anti-PrP antibodies stimulates a neuronal allergenic response.Methods: Initially, we predicted the allergenicity of the epitope sequences associated with ‘neurotoxic’ anti-PrP antibodies using allergenicity prediction servers. We then investigated whether anti-PrP antibody treatment of neuronal (N2a) and microglia (N11) cell lines leads to a neuronal allergenic response.Results: We found that both tail- and globular-epitopes were allergenic. Specifically, binding regions that contain epitopes for ‘neurotoxic’ antibodies such as ICSM18 (146-159), ICSM35 (91-110), POM 1 (138-147), POM 2 (57-88) and POM 3 (95-100) lead to activation of allergenic related proteins. Following direct application of anti-PrPC antibodies on N2a cells, mass spectrometry analysis identified 4 neuronal allergenic-related proteins when compared with untreated cells. Furthermore, mass spectrometry analysis identified 8 neuronal allergenic-related proteins following cross-linking N11 cells with anti-PrPC antibodies prior to co-culture with N2a cells, when compared with untreated cells. Of importance, we showed that the allergenic effects triggered by the anti-PrP antibodies were more potent when antibody-treated microglia were co-cultured with the neuroblastoma cell line. Furthermore, in both direct and co-culture with antibody-treated microglia, we demonstrate that the allergenic proteome was part of the PrPC-interactome. Conclusions: This study showed for the first time that anti-PrP antibody binding to PrPC triggers a neuronal allergenic response (we termed ‘IgG-Mediated Neuronal Allergenic Toxicity’) and highlights the important role of microglia in triggering IgG-mediated neuronal allergenic toxicity. Moreover, this study provides an important impetus for including allergenic assessment of therapeutic antibodies for neurodegenerative to derive safe and targeted biotherapeutics.


Author(s):  
Chia-Yi Hsu ◽  
Tsung-Hua Hsieh ◽  
Hsiao-Yun Lin ◽  
Chi-Yu Lu ◽  
Hui-Wen Lo ◽  
...  

Abstract Context Small extracellular vesicles (sEVs) have emerged as modulators of the disease microenvironment, thereby supporting disease progression. However, the potential role of EVs and their content to the pathophysiology of endometriosis remain unclear. Objective This work aimed to investigate whether the EVs from eutopic (Eu) and ectopic (Ec) endometrial stromal cells (ESCs) differ with respect to protein composition and role in endometriosis. Methods Human Eu and Ec endometrium–derived ESCs were isolated from samples of the same patients (n = 3). sEVs were isolated from ESCs via ultracentrifugation; these sEVs were characterized by Western blotting, transmission electron microscopy, and nanoparticle tracking analysis and analyzed using mass spectrometry. The potential role of EcESCs-derived sEVs (EcESCs-sEVs) in endometriosis was explored by assaying their effects on cell viability/proliferation, migration, and angiogenesis. Results In total, 105 ESCs-sEV–associated proteins were identified from EcESCs-sEVs and EuESCs-sEVs by mass spectrometry analysis. The protein content differed between EcESCs-sEVs and EuESCs-sEVs, with annexin A2 (ANXA2) being the most prominent difference—present in EcESCs-sEVs but not EuESCs-sEVs. We also found that sEVs-ANXA2 regulates the motility, proliferation, and angiogenesis of ESCs via the extracellularly regulated kinase (ERK)/STAT3 pathway. Notably, treatment of ESCs with sEVs-ANXA2 resulted in increased proliferation and motility, suggesting that sEVs-ANXA2 may be involved in regulating endometriosis. Our data suggest that EcESCs-sEVs-ANXA2 regulates the motility and the angiogenic potential of ESCs, implying a role for sEVs-ANXA2 in the pathogenesis of endometriosis. Conclusion The study of sEVs-ANXA2 from Ec endometriotic cells uncovers a new mechanism of endometriosis progression and will inform the development of novel therapeutic strategies.


Sign in / Sign up

Export Citation Format

Share Document