-
Toxins Nov 2018Fungicide application remains amongst the most widely used methods of fungal control in agroecosystems. However, the extensive use of fungicides poses hazards to human...
Fungicide application remains amongst the most widely used methods of fungal control in agroecosystems. However, the extensive use of fungicides poses hazards to human health and the natural environment and does not always ensure the effective decrease of mycotoxins in food and feed. Nowadays, the rising threat from mycotoxin contamination of staple foods has stimulated efforts in developing alternative strategies to control plant pathogenic fungi. A substantial effort is focused on the identification of plant-derived compounds inhibiting mycotoxin production by plant pathogenic fungi. l-Pyroglutamic acid has recently been suggested as playing a role in the response of barley to toxigenic Fusaria. Considering the above, we studied the response of various strains of sensu stricto to different levels of l-pyroglutamic acid on solid YES (yeast extract sucrose) media. l-Pyroglutamic acid decreased the accumulation of trichothecenes in all examined strains. Gene expression studies addressing genes (4, 5, and 10), which induce the biosynthesis of trichothecenes, revealed the production of mycotoxins by l-pyroglutamic acid to be inhibited at the transcriptional level. Besides inhibitory effects on mycotoxin production, l-pyroglutamic acid exhibited variable and concentration-related effects on phenylpropanoid production by fungi. Accumulation of most of the fungal-derived phenolic acids decreased in the presence of 100 and 400 µg/g of l-pyroglutamic acid. However, a higher dose (800 µg/g) of l-pyroglutamic acid increased the accumulation of -cinnamic acid in the media. The accumulation of fungal-derived naringenin increased in the presence of l-pyroglutamic acid. Contrasting results were obtained for quercetin, apigenin, luteolin, and kaempferol, the accumulation of which decreased in the samples treated with 100 and 400 µg/g of l-pyroglutamic acid, whereas the highest l-pyroglutamic acid concentration (800 µg/g) seemed to induce their biosynthesis. The results obtained in this study provide new insights for breeders involved in studies on resistance against Fusaria.
Topics: Drug Resistance, Fungal; Flavonoids; Fusarium; Gene Expression Regulation, Fungal; Pyrrolidonecarboxylic Acid; Trichothecenes
PubMed: 30477204
DOI: 10.3390/toxins10120492 -
Journal of Nuclear Medicine : Official... Mar 2017The purinergic receptor subtype 7 (P2X7R) represents a novel molecular target for imaging neuroinflammation via PET. GSK1482160, a potent P2X7R antagonist, has high...
The purinergic receptor subtype 7 (P2X7R) represents a novel molecular target for imaging neuroinflammation via PET. GSK1482160, a potent P2X7R antagonist, has high receptor affinity, high blood-brain barrier penetration, and the ability to be radiolabeled with C. We report the initial physical and biologic characterization of this novel ligand. C-GSK1482160 was synthesized according to published methods. Cell density studies were performed on human embryonic kidney cell lines expressing human P2X7R (HEK293-hP2X7R) and underwent Western blotting, an immunofluorescence assay, and radioimmunohistochemistry analysis using P2X7R polyclonal antibodies. Receptor density and binding potential were determined by saturation and association-disassociation kinetics, respectively. Peak immune response to lipopolysaccharide treatment in mice was determined in time course studies and analyzed via Iba1 and P2X7R Western blotting and Iba1 immunohistochemistry. Whole-animal biodistribution studies were performed on saline- or lipopolysaccharide-treated mice at 15, 30, and 60 min after radiotracer administration. Dynamic in vivo PET/CT was performed on the mice at 72 h after administration of saline, lipopolysaccharide, or lipopolysaccharide + blocking, and 2-compartment, 5-parameter tracer kinetic modeling of brain regions was performed. P2X7R changed linearly with concentrations or cell numbers. For high-specific-activity C-GSK1482160, receptor density and K were 1.15 ± 0.12 nM and 3.03 ± 0.10 pmol/mg, respectively, in HEK293-hP2X7R membranes. Association constant , dissociation constant , and binding potential (/) in HEK293-hP2X7R cells were 0.2312 ± 0.01542 min⋅nM, 0.2547 ± 0.0155 min, and 1.0277 ± 0.207, respectively. Whole-brain Iba1 expression in lipopolysaccharide-treated mice peaked by 72 h on immunohistochemistry, and Western blot analysis of P2X7R for saline- and lipopolysaccharide-treated brain sections showed a respective 1.8- and 1.7-fold increase in signal enhancement at 72 h. Biodistribution of C-GSK1482160 in saline- and lipopolysaccharide-treated mice at 72 h was statistically significant across all tissues studied. In vivo dynamic C-GSK1482160 PET/CT of mice at 72 h after administration of saline, lipopolysaccharide, or lipopolysaccharide + blocking showed a 3.2-fold increase and 97% blocking by 30 min. The total distribution volumes for multiple cortical regions and the hippocampus showed statistically significant increases and were blocked by an excess of authentic standard GSK1482160. The current study provides compelling data that support the suitability of C-GSK1482160 as a radioligand targeting P2X7R, a biomarker of neuroinflammation.
Topics: Animals; Biomarkers; Brain; Carbon Radioisotopes; Encephalitis; Humans; Inflammation Mediators; Mice; Mice, Inbred C57BL; Molecular Imaging; Positron-Emission Tomography; Pyrrolidonecarboxylic Acid; Radiopharmaceuticals; Receptors, Purinergic P2X7; Reproducibility of Results; Sensitivity and Specificity
PubMed: 27765863
DOI: 10.2967/jnumed.116.181354 -
Journal of Epidemiology and Global... Dec 2022Glutamine family amino acids such as glutamate, pyroglutamate, and glutamine have been shown to play important roles in COVID-19. However, it is still unclear about the...
BACKGROUND
Glutamine family amino acids such as glutamate, pyroglutamate, and glutamine have been shown to play important roles in COVID-19. However, it is still unclear about the role of pyroglutamate in COVID-19. Thus, we use a two-sample Mendelian randomization (MR) study to identify the genetic causal link between blood pyroglutamine levels and COVID-19 risk.
METHODS
Pyroglutamine genetic instrumental variables (IVs) were chosen from the largest pyroglutamine-associated genome-wide association studies (GWAS). The largest COVID-19 GWAS dataset was employed to evaluate the causal link between blood pyroglutamine levels and COVID-19 risk using two-sample MR analysis.
RESULTS
We found no significant pleiotropy or heterogeneity of pyroglutamine-associated genetic IVs in COVID-19 GWAS. Interestingly, we found that as pyroglutamine genetically increased, the risk of COVID-19 decreased using inverse variance weighted (IVW) (Beta = - 0.644, p = 0.003; OR = 0.525, 95% CI [0.346-0.798]) and weighted median (Beta = - 0.609, p = 0.013; OR = 0.544, 95% CI [0.337-0.878]).
CONCLUSION
Our analysis suggests a causal link between genetically increased pyroglutamine and reduced risk of COVID-19. Thus, pyroglutamine may be a protective factor for patients with COVID-19.
Topics: Humans; Mendelian Randomization Analysis; Genome-Wide Association Study; Polymorphism, Single Nucleotide; COVID-19; Pyrrolidonecarboxylic Acid; Glutamine
PubMed: 36219338
DOI: 10.1007/s44197-022-00073-1 -
The Journal of Biological Chemistry Jan 2015Thyrotropin-releasing hormone is a tripeptide that consists of 5-oxoproline, histidine, and proline. The peptide is rapidly metabolized by various enzymes. 5-Oxoproline...
Thyrotropin-releasing hormone is a tripeptide that consists of 5-oxoproline, histidine, and proline. The peptide is rapidly metabolized by various enzymes. 5-Oxoproline is produced by enzymatic hydrolysis in a variety of peptides. Previous studies showed that 5-oxoproline could become a possible biomarker for autism spectrum disorders. Here we demonstrate the involvement of SLC16A1 in the transport of 5-oxoproline. An SLC16A1 polymorphism (rs1049434) was recently identified. However, there is no information about the effect of the polymorphism on SLC16A1 function. In this study, the polymorphism caused an observable change in 5-oxoproline and lactate transport via SLC16A1. The Michaelis constant (Km) was increased in an SLC16A1 mutant compared with that in the wild type. In addition, the proton concentration required to produce half-maximal activation of transport activity (K0.5, H (+)) was increased in the SLC16A1 mutant compared with that in the wild type. Furthermore, we examined the transport of 5-oxoproline in T98G cells as an astrocyte cell model. Despite the fact that 5-oxoproline is an amino acid derivative, Na(+)-dependent and amino acid transport systems scarcely contributed to 5-oxoproline transport. Based on our findings, we conclude that H(+)-coupled 5-oxoproline transport is mediated solely by SLC16A1 in the cells.
Topics: Animals; Astrocytes; Biological Transport; Brain; Catalytic Domain; Cell Line, Tumor; Genetic Variation; Humans; Monocarboxylic Acid Transporters; Mutagenesis, Site-Directed; Mutation, Missense; Oocytes; Polymorphism, Genetic; Polymorphism, Single Nucleotide; Protons; Pyrrolidonecarboxylic Acid; RNA, Messenger; Symporters; Xenopus laevis
PubMed: 25371203
DOI: 10.1074/jbc.M114.581892 -
International Journal of Molecular... May 2022The human gonadotropin releasing hormone (GnRH-I) and its sea lamprey analogue GnRH-III specifically bind to GnRH receptors on cancer cells and can be used as targeting...
The human gonadotropin releasing hormone (GnRH-I) and its sea lamprey analogue GnRH-III specifically bind to GnRH receptors on cancer cells and can be used as targeting moieties for targeted tumor therapy. Considering that the selective release of drugs in cancer cells is of high relevance, we were encouraged to develop cleavable, self-immolative GnRH-III-drug conjugates which consist of a -aminobenzyloxycarbonlyl (PABC) spacer between a cathepsin B-cleavable dipeptide (Val-Ala, Val-Cit) and the classical anticancer drugs daunorubicin (Dau) and paclitaxel (PTX). Alongside these compounds, non-cleavable GnRH-III-drug conjugates were also synthesized, and all compounds were analyzed for their antiproliferative activity. The cleavable GnRH-III bioconjugates revealed a growth inhibitory effect on GnRH receptor-expressing A2780 ovarian cancer cells, while their activity was reduced on Panc-1 pancreatic cancer cells exhibiting a lower GnRH receptor level. Moreover, the antiproliferative activity of the non-cleavable counterparts was strongly reduced. Additionally, the efficient cleavage of the Val-Ala linker and the subsequent release of the drugs could be verified by lysosomal degradation studies, while radioligand binding studies ensured that the GnRH-III-drug conjugates bound to the GnRH receptor with high affinity. Our results underline the high value of GnRH-III-based homing devices and the application of cathepsin B-cleavable linker systems for the development of small molecule drug conjugates (SMDCs).
Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Cathepsin B; Cell Line, Tumor; Daunorubicin; Female; Gonadotropin-Releasing Hormone; Humans; Molecular Targeted Therapy; Ovarian Neoplasms; Paclitaxel; Petromyzon; Pyrrolidonecarboxylic Acid; Receptors, LHRH
PubMed: 35563462
DOI: 10.3390/ijms23095071 -
International Journal of Molecular... Jul 2021All organisms confront the challenges of maintaining metabolic homeostasis in light of both variabilities in nutrient supplies and energetic costs of different... (Review)
Review
All organisms confront the challenges of maintaining metabolic homeostasis in light of both variabilities in nutrient supplies and energetic costs of different physiologies and behaviors. While all cells are nutrient sensitive, only relative few cells within Metazoans are nutrient sensing cells. Nutrient sensing cells organize systemic behavioral and physiological responses to changing metabolic states. One group of cells present in the arthropods, is the adipokinetic hormone producing cells (APCs). APCs possess intrinsic nutrient sensors and receive contextual information regarding metabolic state through other endocrine connections. APCs express receptors for different hormones which modulate APC physiology and the secretion of the adipokinetic hormone (AKH). APCs are functionally similar to alpha cells in the mammalian pancreas and display a similar physiological organization. AKH release results in both hypertrehalosemia and hyperlipidemia through high affinity binding to the AKH receptor (AKHR). Another hallmark of AKH signaling is heightened locomotor activity, which accompanies starvation and is thought to enhance foraging. In this review, we discuss mechanisms of nutrient sensing and modulation of AKH release. Additionally, we compare the organization of AKH/AKHR signaling in different taxa. Lastly, we consider the signals that APCs integrate as well as recent experimental results that have expanded the functional repertoire of AKH signaling, further establishing this as both a metabolic and stress hormone.
Topics: Animals; Homeostasis; Humans; Insect Hormones; Nutrients; Oligopeptides; Pyrrolidonecarboxylic Acid; Signal Transduction; Stress, Physiological
PubMed: 34299134
DOI: 10.3390/ijms22147515 -
PloS One 2019Metabolomic approaches have been used to identify new diagnostic biomarkers for various types of cancers, including breast cancer. In this study, we aimed to identify...
Metabolomic approaches have been used to identify new diagnostic biomarkers for various types of cancers, including breast cancer. In this study, we aimed to identify potential biomarkers of breast cancer using plasma metabolic profiling. Furthermore, we analyzed whether these biomarkers had relationships with clinicopathological characteristics of breast cancer. Our study used two liquid chromatography-mass spectrometry sets: a discovery set (40 breast cancer patients and 30 healthy controls) and a validation set (30 breast cancer patients and 16 healthy controls). All breast cancer patients were randomly selected from among stage I-III patients who underwent surgery between 2011 and 2016. First, metabolites distinguishing cancer patients from healthy controls were identified in the discovery set. Then, consistent and reproducible metabolites were evaluated in terms of their utility as possible biomarkers of breast cancer. Receiver operating characteristic (ROC) analysis was applied to the discovery set, and ROC cut-off values for the identified metabolites derived therein were applied to the validation set to determine their diagnostic performance. Ultimately, four candidate biomarkers (L-octanoylcarnitine, 5-oxoproline, hypoxanthine, and docosahexaenoic acid) were identified. L-octanoylcarnitine showed the best diagnostic performance, with a 100.0% positive predictive value. Also, L-octanoylcarnitine levels differed according to tumor size and hormone receptor expression. The plasma metabolites identified in this study show potential as biomarkers allowing early diagnosis of breast cancer. However, the diagnostic performance of the metabolites needs to be confirmed in further studies with larger sample sizes.
Topics: Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Breast Neoplasms; Carnitine; Case-Control Studies; Chromatography, Liquid; Docosahexaenoic Acids; Female; Humans; Hypoxanthine; Mass Spectrometry; Metabolomics; Middle Aged; Pyrrolidonecarboxylic Acid
PubMed: 31794572
DOI: 10.1371/journal.pone.0225129 -
Cardiovascular Diabetology Jun 2020Although an increased arterial stiffness has been associated with traditional coronary risk factors, the risk factors and pathology of arterial stiffness remain unclear....
BACKGROUND
Although an increased arterial stiffness has been associated with traditional coronary risk factors, the risk factors and pathology of arterial stiffness remain unclear. In this study, we aimed to identify the plasma metabolites associated with arterial stiffness in patients with type 2 diabetes mellitus.
METHODS
We used the metabolomic data of 209 patients with type 2 diabetes as the first dataset for screening. To form the second dataset for validation, we enlisted an additional 31 individuals with type 2 diabetes. The non-targeted metabolome analysis of fasting plasma samples using gas chromatography coupled with mass spectrometry and the measurement of brachial-ankle pulse wave velocity (baPWV) were performed.
RESULTS
A total of 65 annotated metabolites were detected. In the screening dataset, there were statistically significant associations between the baPWV and plasma levels of indoxyl sulfate (r = 0.226, p = 0.001), mannitol (r = 0.178, p = 0.010), mesoerythritol (r = 0.234, p = 0.001), and pyroglutamic acid (r = 0.182, p = 0.008). Multivariate regression analyses revealed that the plasma levels of mesoerythritol were significantly (β = 0.163, p = 0.025) and that of indoxyl sulfate were marginally (β = 0.124, p = 0.076) associated with baPWV, even after adjusting for traditional coronary risk factors. In the independent validation dataset, there was a statistically significant association between the baPWV and plasma levels of indoxyl sulfate (r = 0.430, p = 0.016). However, significant associations between the baPWV and plasma levels of the other three metabolites were not confirmed.
CONCLUSIONS/INTERPRETATION
The plasma levels of indoxyl sulfate were associated with arterial stiffness in Japanese patients with type 2 diabetes. Although the plasma levels of mannitol, mesoerythritol, and pyroglutamic acid were also associated with arterial stiffness, further investigation is needed to verify the results.
Topics: Aged; Ankle Brachial Index; Biomarkers; Diabetes Mellitus, Type 2; Erythritol; Female; Gas Chromatography-Mass Spectrometry; Humans; Indican; Male; Mannitol; Metabolomics; Middle Aged; Peripheral Arterial Disease; Pyrrolidonecarboxylic Acid; Vascular Stiffness
PubMed: 32527273
DOI: 10.1186/s12933-020-01057-w -
Alzheimer's Research & Therapy Jan 2020Pyroglutamate-3 Aβ (pGlu-3 Aβ) is an N-terminally truncated and post-translationally modified Aβ species found in Alzheimer's disease (AD) brain. Its increased...
BACKGROUND
Pyroglutamate-3 Aβ (pGlu-3 Aβ) is an N-terminally truncated and post-translationally modified Aβ species found in Alzheimer's disease (AD) brain. Its increased peptide aggregation propensity and toxicity make it an attractive emerging treatment strategy for AD. We address the question of how the effector function of an anti-pGlu-3 Aβ antibody influences the efficacy of immunotherapy in mouse models with AD-like pathology.
METHODS
We compared two different immunoglobulin (Ig) isotypes of the same murine anti-pGlu-3 Aβ mAb (07/1 IgG1 and 07/2a IgG2a) and a general N-terminal Aβ mAb (3A1 IgG1) for their ability to clear Aβ and protect cognition in a therapeutic passive immunotherapy study in aged, plaque-rich APP/PS1ΔE9 transgenic (Tg) mice. We also compared the ability of these antibodies and a CDC-mutant form of 07/2a (07/2a-k), engineered to avoid complement activation, to clear Aβ in an ex vivo phagocytosis assay and following treatment in APPxhQC double Tg mice, and to activate microglia using longitudinal microPET imaging with TSPO-specific F-GE180 tracer following a single bolus antibody injection in young and old Tg mice.
RESULTS
We demonstrated significant cognitive improvement, better plaque clearance, and more plaque-associated microglia in the absence of microhemorrhage in aged APP/PS1ΔE9 Tg mice treated with 07/2a, but not 07/1 or 3A1, compared to PBS in our first in vivo study. All mAbs cleared plaques in an ex vivo assay, although 07/2a promoted the highest phagocytic activity. Compared with 07/2a, 07/2a-k showed slightly reduced affinity to Fcγ receptors CD32 and CD64, although the two antibodies had similar binding affinities to pGlu-3 Aβ. Treatment of APPxhQC mice with 07/2a and 07/2a-k mAbs in our second in vivo study showed significant plaque-lowering with both mAbs. Longitudinal F-GE180 microPET imaging revealed different temporal patterns of microglial activation for 3A1, 07/1, and 07/2a mAbs and no difference between 07/2a-k and PBS-treated Tg mice.
CONCLUSION
Our results suggest that attenuation of behavioral deficits and clearance of amyloid is associated with strong effector function of the anti-pGlu-3 Aβ mAb in a therapeutic treatment paradigm. We present evidence that antibody engineering to reduce CDC-mediated complement binding facilitates phagocytosis of plaques without inducing neuroinflammation in vivo. Hence, the results provide implications for tailoring effector function of humanized antibodies for clinical development.
Topics: Alzheimer Disease; Alzheimer Vaccines; Amyloid beta-Peptides; Animals; Antibodies, Monoclonal; Cognition; Disease Models, Animal; Immunization, Passive; Immunoglobulin G; Mice; Mice, Transgenic; Neuroglia; Protein Processing, Post-Translational; Pyrrolidonecarboxylic Acid
PubMed: 31931873
DOI: 10.1186/s13195-019-0579-8 -
World Journal of Gastroenterology May 2017To identify metabolic signatures in urine samples from healthy and inflammatory bowel disease (IBD) children.
AIM
To identify metabolic signatures in urine samples from healthy and inflammatory bowel disease (IBD) children.
METHODS
We applied liquid chromatography and gas chromatography coupled to targeted mass spectrometry (MS)-based metabolite profiling to identify and quantify bile acids and host-gut microbial metabolites in urine samples collected from 21 pediatric IBD patients monitored three times over one year (baseline, 6 and 12 mo), and 27 age- and gender-matched healthy children.
RESULTS
urinary metabolic profiles of IBD children differ significantly from healthy controls. Such metabolic differences encompass central energy metabolism, amino acids, bile acids and gut microbial metabolites. In particular, levels of pyroglutamic acid, glutamic acid, glycine and cysteine, were significantly higher in IBD children in the course of the study. This suggests that glutathione cannot be optimally synthesized and replenished. Whilst alterations of the enterohepatic circulation of bile acids in pediatric IBD patients is known, we show here that non-invasive urinary bile acid profiling can assess those altered hepatic and intestinal barrier dysfunctions.
CONCLUSION
The present study shows how non-invasive sampling of urine followed by targeted MS-based metabonomic analysis can elucidate and monitor the metabolic status of children with different GI health/disease status.
Topics: Adolescent; Anthropometry; Bile Acids and Salts; Body Composition; Case-Control Studies; Child; Colitis, Ulcerative; Crohn Disease; Cysteine; Female; Gas Chromatography-Mass Spectrometry; Gastrointestinal Microbiome; Glutamic Acid; Glutathione; Glycine; Humans; Inflammation; Inflammatory Bowel Diseases; Male; Metabolome; Metabolomics; Microbial Interactions; Phenotype; Pyrrolidonecarboxylic Acid; Signal Transduction; Urine
PubMed: 28611517
DOI: 10.3748/wjg.v23.i20.3643