Endogenous molecules released by haemocytes receiving Sargassum oligocystum extract lead to downstream activation and synergize innate immunity in white shrimp Litopenaeus vannamei.

White shrimp Litopenaeus vannamei haemocytes receiving immunostimulating Sargassum oligocystum extract (SE) caused necrosis in haemocyte cells, which released endogenous EM-SE molecules. This study examined the immune response of white shrimp L. vannamei receiving SE and EM-SE in vitro and in vivo. Shrimp haemocytes receiving SE exhibited degranulation, changes in cell size and cell viability, necrosis and a release of EM-SE. Shrimp haemocytes receiving SE, EM-SE, and the SE + EM-SE mixture (SE + EM-SE) increased their phenoloxidase (PO) activity which was significantly higher in shrimp haemocytes receiving the SE + EM-SE mixture. Furthermore, shrimp haemocytes receiving EM-SE showed degranulation and changes in cell size and cell viability. Shrimp receiving SE, EM-SE, and SE + EM-SE all increased their immune parameters, phagocytic activity, clearance efficiency and resistance to Vibrio alginolyticus, being significantly higher in shrimp receiving SE + EM-SE. Meanwhile, the recombinant lipopolysaccharide- and ß-1,3-glucan binding protein of L. vannamei (rLvLGBP) was bound to SE, EM-SE, and SE + EM-SE. We conclude that in shrimp haemocytes receiving a non-self molecule, SE in dying cells released EM-SE which led to downstream activation and synergization of the immune response. This study demonstrated that the innate immunity of shrimp was elicited and enhanced by a mixture of endogenous molecules and exogenous substances (or immunostimulants).

Development and evaluation of a comprehensive workflow for suspect screening of exposome-related xenobiotics and phase II metabolites in diverse human biofluids.

Suspect and non-target screening (SNTS) methods are being promoted in order to decode the human exposome since a wide chemical space can be analysed in a diversity of human biofluids. However, SNTS approaches in the exposomics field are infra-studied in comparison to environmental or food monitoring studies. In this work, a comprehensive suspect screening workflow was developed to annotate exposome-related xenobiotics and phase II metabolites in diverse human biofluids. Precisely, human urine, breast milk, saliva and ovarian follicular fluid were employed as samples and analysed by means of ultra-high performance liquid chromatography coupled with high resolution tandem mass spectrometry (UHPLC-HRMS/MS). To automate the workflow, the "peak rating" parameter implemented in Compound Discoverer 3.3.2 was optimized to avoid time-consuming manual revision of chromatographic peaks. In addition, the presence of endogenous molecules that might interfere with the annotation of xenobiotics was carefully studied as the employment of inclusion and exclusion suspect lists. To evaluate the workflow, limits of identification (LOIs) and type I and II errors (i.e., false positives and negatives, respectively) were calculated in both standard solutions and spiked biofluids using 161 xenobiotics and 22 metabolites. For 80.3 % of the suspects, LOIs below 15 ng/mL were achieved. In terms of type I errors, only two cases were identified in standards and spiked samples. Regarding type II errors, the 7.7 % errors accounted in standards increased to 17.4 % in real samples. Lastly, the use of an inclusion list for endogens was favoured since it avoided 18.7 % of potential type I errors, while the exclusion list caused 7.2 % of type II errors despite making the annotation workflow less time-consuming.

Cross interactions between Apolipoprotein E and amyloid proteins in neurodegenerative diseases.

Three common Apolipoprotein E isoforms, ApoE2, ApoE3, and ApoE4, are key regulators of lipid homeostasis, among other functions. Apolipoprotein E can interact with amyloid proteins. The isoforms differ by one or two residues at positions 112 and 158, and possess distinct structural conformations and functions, leading to isoform-specific roles in amyloid-based neurodegenerative diseases. Over 30 different amyloid proteins have been found to share similar characteristics of structure and toxicity, suggesting a common interactome. The molecular and genetic interactions of ApoE with amyloid proteins have been extensively studied in neurodegenerative diseases, but have not yet been well connected and clarified. Here we summarize essential features of the interactions between ApoE and different amyloid proteins, identify gaps in the understanding of the interactome and propose the general interaction mechanism between ApoE isoforms and amyloid proteins. Perhaps more importantly, this review outlines what we can learn from the interactome of ApoE and amyloid proteins; that is the need to see both ApoE and amyloid proteins as a basis to understand neurodegenerative diseases.

Visualizing the spatial distribution of endogenous molecules in wolfberry fruit at different development stages by matrix-assisted laser desorption/ionization mass spectrometry imaging.

Wolfberry fruit has been attracting attention for centuries in Asian countries as a traditional herbal medicine and valuable nourishing tonic. Revealing the spatial distribution changes of important endogenous molecules during plant development is of great significance for investigating the physiological roles, nutritional and potential functional values of phytochemicals in wolfberry fruit. However, their spatial distribution information during fruit development has not been extensively explored due to the lack of efficient analytical techniques. In this work, matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) was performed to visualize the spatial distribution of the endogenous molecules during fruit development. From the mass spectrum imaging, the choline, betaine and citric acid were distributed evenly throughout the entire fruit at all development stages. The hexose was distributed in the endocarp and flesh tissue, while sucrose was located in the seeds. Additionally, several phenolic acids and flavonoids were accumulated in the exocarp during fruit development, which indicated that they seemingly played protective roles in wolfberry fruit growth progress against abiotic and biotic stress. From the collected data, we found that the signal intensities of citric acid were decreased, while choline, betaine, hexose and sucrose were increased with fruit development. These results indicate that MALDI-MSI may become a favorable tool for studying of the spatial distribution and effective use of endogenous molecules, which provide a simple and intuitive way for authenticity identification, classification of drug food homologous foods and further understanding the physiological roles of endogenous molecules.

On-tissue chemical derivatization reagents for matrix-assisted laser desorption/ionization mass spectrometry imaging.

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) is a key tool for the analysis of biological tissues. It provides spatial and quantitative information about different types of analytes within tissue sections. Despite the increasing improvements of this technique, the low detection sensitivity of some compounds remains an important challenge to overcome. Poor sensitivity is related to weak ionization efficiency, low abundance of analytes and matrix ions, or endogenous interferences. On-tissue chemical derivatization (OTCD) has proven to be an important solution to these issues and is increasingly employed in MALDI MSI studies. OTCD reagents, synthesized or commercially available, have been essentially used for the detection of small exogenous or endogenous molecules within tissues. Optimally, an OTCD reaction is performed in mild conditions, in an acceptable range of time, preserves the integrity of the tissues, and prevents the delocalization. In addition to their reactivity with a targeted chemical function, some OTCD reagents can also be used as a matrix, which simplifies the sample preparation procedure. In this review, we present an exhaustive overview of OTCD reagents and methods used in MALDI MSI studies.

Spatial Distribution of Endogenous Molecules in Coffee Beans by Atmospheric Pressure Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging.

Mass spectrometry imaging (MSI) is a promising chemical imaging method. Among various endogenous molecules, mapping the concentration and the spatial distribution of specific compounds in the coffee bean tissue is of tremendous significance in its function research, as these compounds are critical to grading coffee beans at the molecular level, determining the geographical origin, and optimizing storage conditions of coffee beans. In this paper, we established an atmospheric pressure (AP) matrix-assisted laser desorption/ionization (MALDI) MSI method for the microscopic distribution analysis of endogenous molecules, for example, sucrose, caffeine, and caffeoylquinic acid, in the coffee bean endosperm. Experiments were done on the differences between coffee beans from eight countries. Principal component analysis (PCA) was performed using IMAGEREVEAL software. The results showed that the chemical composition and relative content of coffee beans from different origins are different. Our work provides a detection method that may be used for coffee bean quality identification, efficient use, product traceability, and product counterfeiting.

Small endogenous molecules as moiety to improve targeting of CNS drugs.

INTRODUCTION: A major challenge in the development of novel neuro-therapeutic agents is to effectively overcome the blood-brain barrier (BBB), which acts as a 'working dynamic barrier'. The core problem in the treatment of neurodegenerative diseases is failed delivery of potential medicines due to their inadequate permeation rate. Areas covered: The present review gives a summary of endogenous moieties used in synthesizing prodrugs, derivatives and bioisosteric drugs appositely designed to structurally resemble physiological molecular entities able to be passively absorbed or carried by specific carrier proteins expressed at BBB level. In particular, this overview focuses on aminoacidic, glycosyl, purinergic, ureic and acidic fragments derivatives, most of which can take advantage from BBB carrier-mediated transporters, where passive diffusion is not permitted. Expert opinion: In the authors' perspective, further progress in this field could expedite successful translation of new chemical entities into clinical trials. Careful rationalization of the linkage between endogenous molecular structures and putative transporters binding sites could allow to useful work-flows and libraries for synthesizing new BBB-crossing therapeutic substances and/or multifunctional drugs for treatments of central disorders.