Endogenous Small Molecules Research Articles

Ponicidin suppresses pancreatic cancer growth by inducing ferroptosis: Insight gained by mass spectrometry-based metabolomics

BackgroundPancreatic cancer is one of the most common malignant tumors of the digestive tract. Ponicidin, a tetracyclic diterpenoid active ingredient extracted from the traditional phytomedicine Rubescens, has high safety and great inhibitory effect on the proliferation of a variety of cancer cells, especially malignant tumor cells of the digestive tract. However, the inhibitory effect and mechanism of ponicidin on pancreatic cancer cells is still unclear. Our study aimed to use metabonomics technology to analyze and explore the suppressive effect of ponidicin against pancreatic cancer cells. MethodsMTT and flow cytometry were conducted to study the potential effect of ponicidin on SW1990 cells. Secondly, UPLC-MS/MS was used to analyze the small molecule metabolites and relevant differential metabolic pathways induced by ponicidin treatment. Furthermore, through the determination of glutathione peroxidase 4 (GPX4) activity and molecular docking simulation experiments, the effects of intracellular GPX4 activity and GSH/GSSG ratio after ponicidin were evaluated. Finally, the determination of the content of iron ions and malondialdehyde in cells, and the experiment of the effect of ferroptosis inhibitors on cell viability, the effect of ponicidin on the induction of ferroptosis in SW1990 cells was also detected. ResultsThe IC50 of ponicidin on SW1990 cells was 20 μM, which could significantly induce cell apoptosis and arrest the cells in G2/M phase. Metabolomics results showed that the contents of endogenous small molecules such as gamma-glutamylcysteine, 5-oxoproline, glutamic acid, reduced glutathione (GSH), oxidized glutathione (GSSG) and arachidonic acid have changed significantly. Main differential compounds were involved in the gamma-glutamyl cycle and polyunsaturated fatty acid metabolism of pancreatic cancer cell lines. Additionally, ponicidin could covalently bind to GSH in SW1990 cells to form a conjugate Pon-GSH, which further reduced the content of free GSH and GPX4 activity in cells. Notably, ponicidin dose-dependently increased levels of iron ions, malondialdehyde and reactive oxygen species in SW1990 cells, and the ferroptosis inhibitors could significantly block the effects of ponicidin on the proliferation of SW1990 cells. ConclusionPonicidin could suppress the pancreatic cancer cell proliferation via inducing ferroptosis by inhibiting the gamma-glutamyl cycle and regulating the polyunsaturated fatty acid metabolism in SW1990 cells.

Characterization of miRNAs in Embryonic, Larval, and Adult Lumpfish Provides a Reference miRNAome for Cyclopterus lumpus.

Simple SummaryLumpfish (Cyclopterus lumpus) is an emergent aquaculture species, and its miRNA repertoire is still unknown. miRNAs are critical post-transcriptional modulators of teleost gene expression. Therefore, a lumpfish reference miRNAome was characterized by small RNA sequencing and miRDeep analysis of samples from different organs and developmental stages. The resulting miRNAome, an essential reference for future expression analyses, consists of 443 unique mature miRNAs from 391 conserved and eight novel miRNA genes. Enrichment of specific miRNAs in particular organs and developmental stages indicates that some conserved lumpfish miRNAs regulate organ and developmental stage-specific functions reported in other teleosts.MicroRNAs (miRNAs) are endogenous small RNA molecules involved in the post-transcriptional regulation of protein expression by binding to the mRNA of target genes. They are key regulators in teleost development, maintenance of tissue-specific functions, and immune responses. Lumpfish (Cyclopterus lumpus) is becoming an emergent aquaculture species as it has been utilized as a cleaner fish to biocontrol sea lice (e.g., Lepeophtheirus salmonis) infestation in the Atlantic Salmon (Salmo salar) aquaculture. The lumpfish miRNAs repertoire is unknown. This study identified and characterized miRNA encoding genes in lumpfish from three developmental stages (adult, embryos, and larvae). A total of 16 samples from six different adult lumpfish organs (spleen, liver, head kidney, brain, muscle, and gill), embryos, and larvae were individually small RNA sequenced. Altogether, 391 conserved miRNA precursor sequences (discovered in the majority of teleost fish species reported in miRbase), eight novel miRNA precursor sequences (so far only discovered in lumpfish), and 443 unique mature miRNAs were identified. Transcriptomics analysis suggested organ-specific and age-specific expression of miRNAs (e.g., miR-122-1-5p specific of the liver). Most of the miRNAs found in lumpfish are conserved in teleost and higher vertebrates, suggesting an essential and common role across teleost and higher vertebrates. This study is the first miRNA characterization of lumpfish that provides the reference miRNAome for future functional studies.

SLC22 Transporters in the Fly Renal System Regulate Response to Oxidative Stress In Vivo.

Several SLC22 transporters in the human kidney and other tissues are thought to regulate endogenous small antioxidant molecules such as uric acid, ergothioneine, carnitine, and carnitine derivatives. These transporters include those from the organic anion transporter (OAT), OCTN/OCTN-related, and organic cation transporter (OCT) subgroups. In mammals, it has been difficult to show a clear in vivo role for these transporters during oxidative stress. Ubiquitous knockdowns of related Drosophila SLC22s—including transporters homologous to those previously identified by us in mammals such as the “Fly-Like Putative Transporters” FLIPT1 (SLC22A15) and FLIPT2 (SLC22A16)—have shown modest protection against oxidative stress. However, these fly transporters tend to be broadly expressed, and it is unclear if there is an organ in which their expression is critical. Using two tissue-selective knockdown strategies, we were able to demonstrate much greater and longer protection from oxidative stress compared to previous whole fly knockdowns as well as both parent and WT strains (CG6126: p < 0.001, CG4630: p < 0.01, CG16727: p < 0.0001 and CG6006: p < 0.01). Expression in the Malpighian tubule and likely other tissues as well (e.g., gut, fat body, nervous system) appear critical for managing oxidative stress. These four Drosophila SLC22 genes are similar to human SLC22 transporters (CG6126: SLC22A16, CG16727: SLC22A7, CG4630: SLC22A3, and CG6006: SLC22A1, SLC22A2, SLC22A3, SLC22A6, SLC22A7, SLC22A8, SLC22A11, SLC22A12 (URAT1), SLC22A13, SLC22A14)—many of which are highly expressed in the kidney. Consistent with the Remote Sensing and Signaling Theory, this indicates an important in vivo role in the oxidative stress response for multiple SLC22 transporters within the fly renal system, perhaps through interaction with SLC22 counterparts in non-renal tissues. We also note that many of the human relatives are well-known drug transporters. Our work not only indicates the importance of SLC22 transporters in the fly renal system but also sets the stage for in vivo studies by examining their role in mammalian oxidative stress and organ crosstalk.

Small Endogenous Ligands Modulation of Nerve Growth Factor Bioactivity: A Structural Biology Overview.

Experiments with cell cultures and animal models have provided solid support for the assumption that Nerve Growth Factor (NGF) plays a key role in the regulation of neuronal cell survival and death. Recently, endogenous ligands have been proposed as physiological modulators of NGF biological activity as part of this regulatory cascade. However, the structural and mechanistic determinants for NGF bioactivity remain to be elucidated. We recently unveiled, by an integrated structural biology approach, the ATP binding sites of NGF and investigated the effects on TrkA and p75NTR receptors binding. These results pinpoint ATP as a genuine endogenous modulator of NGF signaling, paving the way to the characterization of not-yet-identified chemical diverse endogenous biological active small molecules as novel modulators of NGF. The present review aims at providing an overview of the currently available 3D structures of NGF in complex with different small endogenous ligands, featuring the molecular footprints of the small molecules binding. This knowledge is essential for further understanding the functional role of small endogenous ligands in the modulation of neurotrophins signaling in physiological and pathological conditions and for better exploiting the therapeutic potentialities of NGF.

Significance of miRNA in enhancement of flavonoid biosynthesis.

Flavonoid metabolism shows very strong plasticity in plant development and coping with the changing environment. Flavonoid biosynthesis is regulated by many metabolic pathways, including transcriptional regulation, post-transcriptional control, post-translational regulationand epigenetic regulation. miRNA is a form of endogenous noncoding single-strand small molecule RNA that primarily regulates the expression of target genes horizontally after transcription through splicing and translational suppression. It also plays an important role in regulating plant growth and development, secondary metabolism and biotic and abiotic stress. miRNA can regulate the formation of flavonoids by acting on structural genes or indirectly by using an MBW transcription complex comprising MYB-bHLH-WD40. This study summarizes the biosynthesis and mechanisms of miRNA, and provides a summary of the mechanisms of miRNAs involved in production of flavonoids, in order to elucidate the biosynthesis pathway and complex regulatory network of plant flavonoids. We aim to provide new insights into improving the content of flavonoid active ingredients in plants.

MicroRNAs: Their Role in Metabolism, Tumor Microenvironment, and Therapeutic Implications in Head and Neck Squamous Cell Carcinoma.

Simple SummaryHead and neck squamous cell carcinoma (HNSCC), which arises from the oral epithelium, is one of the most common cancers worldwide. Despite excellent diagnosis and treatment improvements, the mortality rate associated with HNSCC is still extremely high. Current data suggest that dysregulation of exosomes and metabolic abnormalities are involved in the initiation and progression of HNSCC. Thus, approaches for targeting exosomes in the tumor microenvironment and metabolic reprogramming pathways represent potential therapeutic strategies. Moreover, some miRNAs are thought to have significant functions in regulating the progression of HNSCC. The present article aims to summarize the current knowledge concerning the important miRNAs in both exosomes and cancer metabolism, as well as discuss future perspectives regarding their future diagnostic potential and treatment recommendations.MicroRNAs (miRNAs) are endogenous small non-coding RNA molecules that negatively regulate gene expression by binding to target mRNAs. Deregulated miRNAs can act as either oncogenic miRNAs or tumor suppressor miRNAs in controlling proliferation, differentiation, apoptosis, metastasis, epithelial–mesenchymal transition, and immune responses, which are all involved in the carcinogenesis process of HNSCC. Recent findings have shown that metabolic reprogramming is an important hallmark of cancer, which is necessary for malignant transformation and tumor development. Some reprogrammed metabolisms are believed to be required for HNSCC against an unfavorable tumor microenvironment (TME). The TME is composed of various cell types embedded in the altered extracellular matrix, among which exosomes, secreted by cancer cells, are one of the most important factors. Tumor-derived exosomes reshape the tumor microenvironment and play a crucial role in cell-to-cell communication during HNSCC development. Exosomes encapsulate many biomolecules, including miRNAs, circulate in body fluids, and can transmit intercellular regulatory messages to nearby and distant sites, which indicates that exosomal miRNAs have the potential to become non-invasive biomarkers. This review aims to clarify the functions of diverse miRNAs in HNSCC metabolic reprogramming and tumor-derived exosomes. In addition, it also emphasizes the potential role of miRNA as a biomarker in the diagnosis, prognosis, and treatment of HNSCC cancer.

Urocanic acid enhances memory consolidation and reconsolidation in novel object recognition task

Urocanic acid (UCA) is an endogenous small molecule that is elevated in skin, blood and brain after sunlight exposure, mainly playing roles in the periphery systems. Few studies have investigated the role of UCA in the central nervous system. In particular, its role in memory consolidation and reconsolidation is still unclear. In the present study, we investigated the effect of intraperitoneal injection of UCA on memory consolidation and reconsolidation in a novel object recognition memory (ORM) task. In the consolidation version of the ORM task, the protocol involved three phases: habituation, sampling and test. UCA injection immediately after the sampling period enhanced ORM memory performance; UCA injection 6 h after sampling did not affect ORM memory performance. In the reconsolidation version of the ORM task, the protocol involved three phases: sampling, reactivation and test. UCA injection immediately after reactivation enhanced ORM memory performance; UCA injection 6 h after reactivation did not affect ORM memory performance; UCA injection 24 h after sampling without reactivation did not affect ORM memory performance. This UCA-enhanced memory performance was not due to its effects on nonspecific responses such as locomotor activity and exploratory behavior. The results suggest that UCA injection enhances consolidation and reconsolidation of an ORM task, which further extends previous research on UCA effects on learning and memory.

Postmortem Metabolomics: Strategies to Assess Time-Dependent Postmortem Changes of Diazepam, Nordiazepam, Morphine, Codeine, Mirtazapine and Citalopram

Postmortem redistribution (PMR) can result in artificial drug concentration changes following death and complicate forensic case interpretation. Currently, no accurate methods for PMR prediction exist. Hence, alternative strategies were developed investigating the time-dependent postmortem behavior of diazepam, nordiazepam, morphine, codeine, mirtazapine and citalopram. For 477 authentic postmortem cases, femoral blood samples were collected at two postmortem time-points. All samples were quantified for drugs of abuse (targeted; liquid chromatography-tandem mass spectrometry LC-MS/MS) and characterized for small endogenous molecules (untargeted; gas chromatography-high resolution MS (GC-HRMS). Trends for significant time-dependent concentration decreases (diazepam (n = 137), nordiazepam (n = 126)), increases (mirtazapine (n = 55), citalopram (n = 50)) or minimal median postmortem changes (morphine (n = 122), codeine (n = 92)) could be observed. Robust mathematical mixed effect models were created for the generalized postmortem behavior of diazepam and nordiazepam, which could be used to back-calculate drug concentrations towards a time-point closer to the estimated time of death (caution: inter-individual variability). Significant correlations between time-dependent concentration changes of morphine, mirtazapine and citalopram with individual endogenous molecules could be determined; no correlation was deemed strong enough for successful a posteriori estimation on the occurrence of PMR for specific cases. The current dataset did successfully lead to a significant knowledge gain in further understanding the time-dependent postmortem behavior of the studied drugs (of abuse).

The Expression Profiles and Deregulation of UDP-Glycosyltransferase (UGT) Genes in Human Cancers and Their Association with Clinical Outcomes.

Simple SummaryThe human UDP-glycosyltransferase (UGT) superfamily plays a critical role in the metabolism of numerous endogenous and exogenous small lipophilic compounds, including carcinogens, drugs, and bioactive molecules with pro- or anti-cancer activity. Previous studies have documented the expression of UGT genes in several cancers derived from drug-metabolizing organs (e.g., liver, colon, kidney). The present study represents the first to comprehensively assess the expression profiles of UGT genes and their impact on patient survival in nearly 30 different cancers primarily derived from non-drug-metabolizing organs. Briefly, our comprehensive analysis of the transcriptomic (RNAseq) and clinical datasets of 9514 patients from 33 different cancers shows the widespread expression of UGT genes, indicative of active drug metabolism within the tumor through the UGT conjugation pathway. We further identified the UGT genes whose intratumoral expression was associated with patient survival, highlighting the potential of UGT genes as prognostic biomarkers and therapeutic targets in various cancers. The human UDP-glycosyltransferase (UGTs) superfamily has 22 functional enzymes that play a critical role in the metabolism of small lipophilic compounds, including carcinogens, drugs, steroids, lipids, fatty acids, and bile acids. The expression profiles of UGT genes in human cancers and their impact on cancer patient survival remains to be systematically investigated. In the present study, a comprehensive analysis of the RNAseq and clinical datasets of 9514 patients from 33 different TCGA (the Genome Cancer Atlas) cancers demonstrated cancer-specific UGT expression profiles with high interindividual variability among and within individual cancers. Notably, cancers derived from drug metabolizing tissues (liver, kidney, gut, pancreas) expressed the largest number of UGT genes (COAD, KIRC, KIRP, LIHC, PAAD); six UGT genes (1A6, 1A9, 1A10, 2A3, 2B7, UGT8) showed high expression in five or more different cancers. Kaplan–Meier plots and logrank tests revealed that six UGT genes were significantly associated with increased overall survival (OS) rates [UGT1A1 (LUSC), UGT1A6 (ACC), UGT1A7 (ACC), UGT2A3 (KIRC), UGT2B15 (BLCA, SKCM)] or decreased OS rates [UGT2B15 (LGG), UGT8 (UVM)] in specific cancers. Finally, differential expression analysis of 611 patients from 12 TCGA cancers identified 16 UGT genes (1A1, 1A3, 1A6, 1A7, 1A8, 1A9, 1A10, 2A1, 2A3, 2B4, 2B7, 2B11, 2B15, 3A1, 3A2, UGT8) that were up/downregulated in at least one cancer relative to normal tissues. In conclusion, our data show widespread expression of UGT genes in cancers, highlighting the capacity for intratumoural drug metabolism through the UGT conjugation pathway. The data also suggests the potentials for specific UGT genes to serve as prognostic biomarkers or therapeutic targets in cancers.

A Dual Role for Death Receptor 5 in Regulating Cardiac Fibroblast Function.

The fibrotic response is involved in nearly all forms of heart failure and dysregulated responses can lead to enhanced cardiac dysfunction. TNF-related apoptosis-inducing ligand (TRAIL) and its receptor, death receptor (DR) 5, are associated with multiple forms of heart failure, but their role in the heart is poorly defined. Our previous study identified DR5 expression on cardiac fibroblasts however, the impact of DR5 on fibroblast function remains unexplored. To investigate the role of DR5 in cardiac fibroblasts, a variety of fibroblast functions were examined following treatment with the endogenous ligand, TRAIL, or small molecule agonist, bioymifi. DR5 activation did not induce apoptosis in naïve fibroblasts but activated ERK1/2 signaling to increase proliferation. However, upon activation and differentiation to myofibroblasts, DR5 expression was elevated, and DR5 agonists induced caspase 3 activation resulting in myofibroblast apoptosis. To investigate the impact of DR5 regulation of fibroblasts in vivo, a chronic isoproterenol administration model of heart failure was used. Wild-type (WT) mice receiving isoproterenol had increased hypertrophy, cardiomyocyte death, and fibrosis and decreased contractility compared to vehicle treated animals. DR5 knockout (KO) mice had no overt baseline phenotype however, following isoproterenol infusion, increased cardiomyocyte death and hypertrophy in comparison to isoproterenol treated WT animals was observed. DR5KO mice had an augmented fibrotic response with isoproterenol treatment compared with WT, which corresponded with additional decreases in contractility. These findings identify a dual role for DR5 in cardiac fibroblast function through enhanced naïve fibroblast proliferation, which switches to a pro-apoptotic function upon differentiation to myofibroblasts. This is important in heart failure where DR5 activation suppresses maladaptive remodeling and may represent a novel therapeutic target for the treatment of heart failure.

The Role of microRNAs in Pulp Inflammation.

The dental pulp can be affected by thermal, physical, chemical, and bacterial phenomena that stimulate the inflammatory response. The pulp tissue produces an immunological, cellular, and vascular reaction in an attempt to defend itself and resolve the affected tissue. The expression of different microRNAs during pulp inflammation has been previously documented. MicroRNAs (miRNAs) are endogenous small molecules involved in the transcription of genes that regulate the immune system and the inflammatory response. They are present in cellular and physiological functions, as well as in the pathogenesis of human diseases, becoming potential biomarkers for diagnosis, prognosis, monitoring, and safety. Previous studies have evidenced the different roles played by miRNAs in proinflammatory, anti-inflammatory, and immunological phenomena in the dental pulp, highlighting specific key functions of pulp pathology. This systematized review aims to provide an understanding of the role of the different microRNAs detected in the pulp and their effects on the expression of the different target genes that are involved during pulp inflammation.

Dynamic changes of phosphatidylinositol and phosphatidylinositol 4-phosphate levels modulate H+-ATPase and Na+/H+ antiporter activities to maintain ion homeostasis in Arabidopsis under salt stress

Plant metabolites are dynamically modified and distributed in response to environmental changes. However, it is poorly understood how metabolic change functions in plant stress responses. Maintaining ion homeostasis under salt stress requires coordinated activation of two types of central regulators: plasma membrane (PM) H+-ATPase and Na+/H+ antiporter. In this study, we used a bioassay-guided isolation approach to identify endogenous small molecules that affect PM H+-ATPase and Na+/H+ antiporter activities and identified phosphatidylinositol (PI), which inhibits PM H+-ATPase activity under non-stress conditions in Arabidopsis by directly binding to the C terminus of the PM H+-ATPase AHA2. Under salt stress, the phosphatidylinositol 4-phosphate-to-phosphatidylinositol (PI4P-to-PI) ratio increased, and PI4P bound and activated the PM Na+/H+ antiporter. PI prefers binding to the inactive form of PM H+-ATPase, while PI4P tends to bind to the active form of the Na+/H+ antiporter. Consistent with this, pis1 mutants, with reduced levels of PI, displayed increased PM H+-ATPase activity and salt stress tolerance, while the pi4kβ1 mutant, with reduced levels of PI4P, displayed reduced PM Na+/H+ antiporter activity and salt stress tolerance. Collectively, our results reveal that the dynamic change between PI and PI4P in response to salt stress in Arabidopsis is crucial for maintaining ion homeostasis to protect plants from unfavorable environmental conditions.

1: MicroRNAs: Potential For Molecular Modulation Of Mechanically-induced Skin Growth During TE

Purpose:Tissue expansion (TE) is commonly utilized to promote skin growth prior to reconstructing a defect or deformity. In spite of its ubiquitous use, the role of molecular modulators during TE, such as microRNAs (miRNAs), has not previously been studied. MiRNAs are small endogenous molecules that regulate many biological processes, including cell proliferation, differentiation, and inflammatory response. Here, we investigate genome-wide changes in miRNA expression in skin during TE.Methods:Changes in miRNA expression were evaluated in a porcine TE model. Full-thickness skin biopsies were collected after 1 hour, 24 hours, 3 days, and 7 days of expansion, as well as from unexpanded skin (control). RNA extracted from biopsies was analyzed with next-generation sequencing (NGS). Differential expression analysis was performed using R software with the Bioconductor-DESeq2 package. Results were corrected for multiple testing using the Benjamini-Hochberg method. A combination of adjusted p-value < 0.05 and | log2 (fold change) | > 1 were used as the threshold to determine the significance of differentially expressed (DE) miRNAs. Potential target genes for DE miRNAs were identified by in silico analysis using three data bases: miRDB, miRTarBase, and DIANA Tools with Tarbase. Functional enrichment analysis of target genes was performed using the g:GOSt functional profiling tool, and results were visualized using R and Cytoscape software.Results:We identified 52 miRNAs that were differentially upregulated (n = 18) or downregulated (n = 34) during at least one of the tested timepoints during TE. At the four time points (1 hour, 24 hours, 3 days and 7 days), there were 15, 6, 22, and 20 DE miRNAs, respectively. Eight miRNAs (ssc-miR-193a-5p, ssc-miR-21, ssc-miR-9-1, ssc-miR-708-3p, ssc-miR-212, ssc-miR-196a, ssc-miR-15b, ssc-miR-184) were DE at more than one timepoint. The comparative analysis showed 9, 4, 16 and 15 unique miRNAs after 1 hour, 24, hours, 3 days and 7 days of TE, respectively. Gene Ontology and KEGG pathway analyses for predicted target genes demonstrated enrichment in cellular processes related to metabolism, transcription, translation, signal transduction, cell differentiation, migration, and angiogenesis.

MicroRNA 144 inhibits cell migration and invasion and regulates inflammatory cytokine secretion through targeting toll like receptor 2 in non-small cell lung cancer.

IntroductionMicroRNAs (miRNAs) are endogenous small noncoding RNA molecules involved in modulation of cancer progression. Here, we investigated the possible role of miR-144 in non-small cell lung cancer (NSCLC) development.Material and methodsThe expression of miR-144 and TLR2 in NSCLC tissue and cell lines was determined by quantitative real-time PCR (qPCR). The TargetScan database was used to predict potential target genes of miR-144. Luciferase assay was used to verify the interaction between TLR2 and miR-144. TLR2 protein expression was measured by western blot. The secretion of interleukin (IL)-1β, IL-6 and IL-8 in A549 cells was detected by an ELISA kit. Cell migration and invasion were evaluated by wound healing assay and transwell assay, respectively.ResultsOur results showed that miR-144 was downregulated in NSCLC tissue and cell lines when compared with the normal tissues and cell line (p < 0.05). The protein level of TLR2 in NSCLC tissue and cell lines was significantly higher than that in normal lung tissues. Dual luciferase reporter gene assay showed that miR-144 could bind to the 3ʹUTR of TLR2 specifically. Up-regulation of miR-144 significantly decreased the expression of TLR2. Up-regulation of miR-144 or down-regulation of TLR2 could decrease cell migration, invasion and secretion of IL-1β, IL-6 and IL-8 in A549 cells. Moreover, overexpression of TLR2 rescued the inhibitory effects of miR-144 on migration, invasion and inflammatory factor secretion of A549 cells.ConclusionsmiR-144 could inhibit the migration, invasion and secretion of IL-1β, IL-6 and IL-8 through downregulation of TLR2 expression in A549 cells.

α-Synuclein: An All-Inclusive Trip Around its Structure, Influencing Factors and Applied Techniques.

Alpha-synuclein (αSyn) is a highly expressed and conserved protein, typically found in the presynaptic terminals of neurons. The misfolding and aggregation of αSyn into amyloid fibrils is a pathogenic hallmark of several neurodegenerative diseases called synucleinopathies, such as Parkinson’s disease. Since αSyn is an Intrinsically Disordered Protein, the characterization of its structure remains very challenging. Moreover, the mechanisms by which the structural conversion of monomeric αSyn into oligomers and finally into fibrils takes place is still far to be completely understood. Over the years, various studies have provided insights into the possible pathways that αSyn could follow to misfold and acquire oligomeric and fibrillar forms. In addition, it has been observed that αSyn structure can be influenced by different parameters, such as mutations in its sequence, the biological environment (e.g., lipids, endogenous small molecules and proteins), the interaction with exogenous compounds (e.g., drugs, diet components, heavy metals). Herein, we review the structural features of αSyn (wild-type and disease-mutated) that have been elucidated up to present by both experimental and computational techniques in different environmental and biological conditions. We believe that this gathering of current knowledge will further facilitate studies on αSyn, helping the planning of future experiments on the interactions of this protein with targeting molecules especially taking into consideration the environmental conditions.

MicroRNA mediated therapeutic effects of natural agents in prostate cancer.

Several natural products, extensively studied for their anticancer activities, have been found to play an efficient role in preventing prostate cancer (PCa). Recently many natural agents have been reported to modulate microRNAs (miRNAs), that are involved in cancer cell growth. The microRNAs are endogenous small noncoding ribonucleic acid molecules that regulate various biological processes through an elegant mechanism of post-transcriptional control of gene expression. Besides being involved in cancer initiation, progression, angiogenesis, inflammation, they have been reported to be responsible for chemoresistance, and radioresistance of tumors. The dysregulated miRNA expression has been associated with many cancers including PCa. Over the past several years, it has been found that natural agents are good regulators of miRNAs and have a role in PCa also. Understanding the molecular mechanisms involving miRNAs by natural agents could result in developing useful strategies to combat this deadly disease. In order to collect research articles, the PubMed search engine was used with keywords 'prostate cancer' and 'natural agents' and 2007 papers were retrieved, further refinement with keywords 'phytochemical' and 'prostate cancer' showed 503 papers. Data was collected from research articles, published from 2010 to 2021. From these, research articles showing miRNA-mediated mechanisms were selected. In this review, we have summarized the information available on the modulation of miRNAs by natural agents, their derivatives, and various combinatorial strategies with chemo/radiation therapy for the mitigation of PCa. Based on the current review of literature, it has been found that the use of natural agents is a novel approach for altering miRNA expression strongly associated with PCa development, recurrence and resistance.

Chemical Images on Fingerprints Revealed with Mass Spectrometry

Commercially available UV-adsorbent TiO2 nanoparticles were used to assist laser/desorption ionization in the course of matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI). Titanium nano-powders proved extremely stable and efficient for small molecule ionization, with negligible background noise in the low mass region (m/z &lt; 500 Da). Validation steps were carried out, assessing detection limits and comparing the results to those of the established DESI/Orbitrap technique. The new analytical method was used to reveal the molecular distribution of endogenous (lipids) and exogenous (analgesics and antipyretics) compounds in latent finger marks (LFMs). The detection limits of endogenous fatty acids and small molecules such as caffeine were in the range of fmol/mm2 on LFMs. The technique separated overlapping latent finger marks, exploiting the differences in lipid expression of human skin. Finally, the method was used to prove contact between skin and objects contaminated by different substances, such as credit cards and paper clips, with chemical images that maintain the shape of the objects on the LFM.

High-Throughput Untargeted Serum Metabolomics Analysis of Hyperuricemia Patients by UPLC-Q-TOF/MS.

Hyperuricemia (HUA) as a metabolic disease is closely associated with metabolic disorders. The etiology and pathogenesis of HUA are not fully understood, so there is no radical cure so far. Metabolomics, a specialized study of endogenous small molecule substances, has become a powerful tool for metabolic pathway analysis of selected differential metabolites, which is helpful for initially revealing possible development mechanisms of various human diseases. Twenty HUA patients and 20 healthy individuals participated in the experiment, and ultrahigh performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF/MS) was employed to investigate serum samples to find differential metabolites. The statistical techniques used were principal component analysis and orthogonal partial least-squares discriminant analysis. The differences in metabolomics results of samples after pretreatment with different solvents were compared, 38, 20, 26, 28, 33, 50, and 40 potential differential metabolites were found, respectively, in HUA patient samples, and each group involved different metabolic pathways. Repetitive metabolites were removed, 138 differential metabolites in HUA serum were integrated for analysis, and the human body was affected by 7 metabolic pathways of glycerophospholipid metabolism, sphingolipid metabolism, arachidonic acid metabolism, linoleic acid metabolism, phenylalanine metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, and α-linolenic acid metabolism. In this work, the metabolomics approach based on UPLC-Q-TOF/MS was employed to investigate serum metabolic changes in HUA patients, 138 potential differential metabolites related to HUA were identified, which provided associations of lipids, amino acids, fatty acids, organic acids, and nucleosides profiles of HUA individuals. Metabolic pathways involved in glycerophospholipid metabolism, sphingolipid metabolism, arachidonic acid metabolism, linoleic acid metabolism, phenylalanine metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, and a-linolenic acid metabolism shed light on the understanding of the etiology and pathogenesis process of HUA.

Into the Labyrinth of the Lipocalin α1-Acid Glycoprotein.

α1-acid glycoprotein (AGP), also known as Orosomucoid (ORM), belongs to the Lipocalin protein family and it is well-known for being a positive acute-phase protein. AGP is mostly found in plasma, with the liver as main contributor, but it is also expressed in other tissues such as the brain or the adipose tissue. Despite the vast literature on AGP, the physiological functions of the protein remain to be elucidated. A large number of activities mostly related to protection and immune system modulation have been described. Recently created AGP-knockout models have suggested novel physiological roles of AGP, including regulation of metabolism. AGP has an outstanding ability to efficiently bind endogenous and exogenous small molecules that together with the complex and variable glycosylation patterns, determine AGP functions. This review summarizes and discusses the recent findings on AGP structure (including glycans), ligand-binding ability, regulation, and physiological functions of AGP. Moreover, this review explores possible molecular and functional connections between AGP and other members of the Lipocalin protein family.

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.