Metabolites In Development Research Articles

351-OR: Investigation of Novel Vitamin D Metabolites and Risk of Islet Autoimmunity and Progression to Type 1 Diabetes

Lower blood 25 (OH) D concentration is associated with increased risk of islet autoimmunity (IA) in some cohorts; it is not known if 25 (OH) D metabolites are important after the onset of IA. We investigated novel vitamin D metabolites in development of IA and progression from IA to T1D in the Diabetes Autoimmunity Study in the Young (DAISY) . IA was defined as two or more consecutive visits positive for ≥ 1 autoantibody (IAA, IA-2A, GAD, ZnT8) . In a nested case-control study, we examined plasma vitamin D metabolites at a pre-seroconversion visit in 114 IA cases and 116 controls. We then followed 144 IA-positive children, of whom 46 developed T1D during a mean follow-up of 8.4 years. Plasma was quantified for 25 (OH) D3, 3-epi-25 (OH) D3, 25 (OH) D2, 24,25 (OH) 2D3, and 1,25 (OH) 2D3, using targeted LC-MS/MS. Logistic regression was used to examine pre-seroconversion metabolites and IA, and Cox regression was used to examine metabolites at seroconversion and progression to T1D. Both models adjusted for age, ethnicity, T1D family history and HLA-DR3/4. Higher pre-seroconversion level of 24,25 (OH) 2D3, an inactive catabolite of 25 (OH) D3, was associated with increased odds of IA (OR: 1.35; 95%CI: 1.03,1.78 per SD of 24,25 (OH) 2D3; p=0.031) . The association between 3-epi-25 (OH) D3 at seroconversion and progression from IA to T1D was modified by age at seroconversion. Higher 3-epi-25 (OH) D3 level was more protective against progression to T1D among children who seroconverted at an older age (HR: 0.47; 95%CI: 0.26, 0.85 for children at the 75th percentile of age at seroconversion (ie years)) compared to children who seroconverted at a younger age (HR: 0.88; 95%CI: 0.63, 1.24 for children at the 25th percentile (ie 3 years)) . Neither IA nor progression to T1D was associated with 25 (OH) D3, 25 (OH) D2 or 1,25 (OH) 2D3.Increased 24,25 (OH) 2D3 may play a role in IA development. The age-related heterogeneity of the relationship between 3-epi-25 (OH) D3 and T1D progression requires further investigation. Disclosure S.Kim: None. K.Kechris: None. O.Fiehn: None. M.Rewers: Consultant; Janssen Research & Development, LLC, Medscape, Provention Bio, Inc., Research Support; Dexcom, Inc., JDRF, Roche Diagnostics USA. J.M.Norris: None. N.L.Zwick: None. P.M.Carry: None. B.C.Defelice: None. R.K.Johnson: None. F.Dong: None. T.Buckner: None. L.A.Vanderlinden: None. B.I.Frohnert: Advisory Panel; Provention Bio, Inc. Funding National Institutes of Health (R01-DK104351, R01-DK32493, RI142483)

Identification of causal metabolites related to multiple autoimmune diseases.

Observational studies provide evidence that metabolites may be involved in the development of autoimmune diseases (ADs), but whether it is causal is still unknown. Based on the large-scale genome-wide association studies (GWAS) summary statistics, we performed two-sample Mendelian randomization (MR) to evaluate the causal associations between human blood metabolites and multiple ADs, which were inflammatory bowel disease (IBD), ulcerative colitis (UC), crohns disease (CD), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), type 1 diabetes (T1D), multiple sclerosis (MS), primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC). After Bonferroni adjustment, we identified 6 causal features of metabolites, i.e., glycerol 2-phosphate for T1D, hexadecanedioate, phenylacetylglutamine and laurylcarnitine for RA, glycine and arachidonate (20:4n6) for CD. Comprehensive sensitive analysis was further performed to validate the robustness of associations. We also observed some overlaps of metabolites among different ADs, implying similar or shared underlying mechanisms in such pathogenic processes. Multivariable MR analysis was then conducted to avoid potential pleiotropic effect of other complex traits. After controlling for several common traits, multivariable MR analysis ruled out most of potential pleiotropic effects and validated independence of identified metabolites. Finally, metabolic pathway analysis was performed based on suggestive metabolites for each AD respectively and a total of seven metabolic pathways were identified. In conclusion, this study provided novel insights into investigating causal role of blood metabolites in development of multiple ADs through a comprehensive genetic pathway.

Revisiting the Complex Pathosystem of Huanglongbing: Deciphering the Role of Citrus Metabolites in Symptom Development

Huanglongbing (HLB), formerly known as citrus greening disease, is one of the most devastating bacterial diseases in citrus worldwide. HLB is caused by ‘Candidatus Liberibacter asiaticus’ bacterium and transmitted by Diaphorina citri. Both ‘Ca. L. asiaticus’ and its vector manipulate the host metabolism to fulfill their nutritional needs and/or to neutralize the host defense responses. Herein, we discuss the history of HLB and the complexity of its pathosystem as well as the geographical distribution of its pathogens and vectors. Recently, our recognition of physiological events associated with ‘Ca. L. asiaticus’ infection and/or D. citri-infestation has greatly improved. However, the roles of citrus metabolites in the development of HLB symptoms are still unclear. We believe that symptom development of HLB disease is a complicated process and relies on a multilayered metabolic network which is mainly regulated by phytohormones. Citrus metabolites play vital roles in the development of HLB symptoms through the modulation of carbohydrate metabolism, phytohormone homeostasis, antioxidant pathways, or via the interaction with other metabolic pathways, particularly involving amino acids, leaf pigments, and polyamines. Understanding how ‘Ca. L. asiaticus’ and its vector, D. citri, affect the metabolic pathways of their host is critical for developing novel, sustainable strategies for HLB management.

Anaerobic degradation of palm oil mill effluent with aluminum bauxite residue for methane production

Experimental study of the anaerobic digestion of palm oil mill effluent (POME) was carried out in an anaerobic upflow sludge blanket reactor (UASBR) with bauxite residue. The production rate of methane 114 L/gCOD/d and CH4 concentration was 205 L gCOD/d at 8.5 g/L of bauxite residue in UASBR. The results showed that the highest methane yield was 37.5 L gCODadded/h; CO2 reduction 1.5 L gCODadded and chemical oxygen demand (COD) removal reached 98.3% at 8.5 g/L of bauxite residue, respectively. The results the best by the modified kinetic model and Umax was 100 mg/L. The kinetic of methane production was also studied. The methane yield coefficient, YM, was 0.69 L CH4/gCODremoved. Anaerobic digestion of acetate was the dominant soluble metabolites in development and specific methanogenic activity results showed that high observed between stoichiometric and experimental higher methane production.

Значение вторичных метаболитов в формировании устойчивости к мучнистой росе деревьев 16-летних культур дуба черешчатого

Значение вторичных метаболитов в формировании устойчивости к мучнистой росе деревьев 16-летних культур дуба черешчатого

LC-MS-Based Metabolic Fingerprinting of Aqueous Humor.

Aqueous humor (AH) is a transparent fluid which fills the anterior and posterior chambers of the eye. It supplies nutrients and removes metabolic waste from avascular tissues in the eye. Proper homeostasis of AH is required to maintain adequate intraocular pressure as well as optical and refractive properties of the eye. Application of metabolomics to study human AH may improve knowledge about the molecular mechanisms of eye diseases. Until now, global analysis of metabolites in AH has been mainly performed using NMR. Among the analytical platforms used in metabolomics, LC-MS allows for the highest metabolome coverage. The aim of this study was to develop a method for extraction and analysis of AH metabolites by LC-QTOF-MS. Different protocols for AH preparation were tested. The best results were obtained when one volume of AH was mixed with one volume of methanol : ethanol (1 : 1). In the final method, 2 µL of extracted sample was analyzed by LC-QTOF-MS. The method allowed for reproducible measurement of over 1000 metabolic features. Almost 250 metabolites were identified in AH and assigned to 47 metabolic pathways. This method is suitable to study the potential role of amino acids, lipids, oxidative stress, or microbial metabolites in development of ocular diseases.

Interplay between gut microbiota, its metabolites and human metabolism: Dissecting cause from consequence

BackgroundAlterations in gut microbiota composition and bacterial metabolites have been increasingly recognized to affect host metabolism and are at the basis of metabolic diseases such as obesity and type 2 diabetes (DM2). Intestinal enteroendocrine cells (EEC's) sense gut luminal content and accordingly secrete hormones that modulate glucose and lipid metabolism and affect satiety. It has become evident that microbial metabolic products significantly affect EEC function. Scope and approachIn this review, we will discuss current insights in the role of the gut microbiota and its metabolites in development of obesity and DM2 and elaborate on interventions that modulate EEC action. Key findings and conclusionsStudies including fecal transplantation and Roux-en-Y gastric bypass (RYGB) in humans and animal models suggest that the gut microbiota and its metabolites causally contribute to development of obesity and DM2. Emerging evidence suggests that the gut microbiota and its metabolites can modulate secretion of EEC hormones that regulate appetite and insulin secretion. Dispersed intestinal expression and low abundance make EEC's difficult to study. Since current intestinal sampling methods in humans are mostly limited to the colon, this leaves a large part of EEC function understudied. It would therefore be relevant to develop means to extend sampling methods throughout to entire GI tract.

Maturation of nematode-induced galls in Medicago truncatula is related to water status and primary metabolism modifications

Root-knot nematodes are obligatory plant parasitic worms that establish and maintain an intimate relationship with their host plants. During a compatible interaction, these nematodes induce the redifferentiation of root cells into multinucleate and hypertrophied giant cells (GCs). These metabolically active feeding cells constitute the exclusive source of nutrients for the nematode. We analyzed the modifications of water status, ionic content and accumulation of metabolites in development and mature galls induced by Meloidogyne incognita and in uninfected roots of Medicago truncatula plants. Water potential and osmotic pressure are significantly modified in mature galls compared to developing galls and control roots. Ionic content is significantly modified in galls compared to roots. Principal component analyses of metabolite content showed that mature gall metabolism is significantly modified compared to developing gall metabolism. The most striking differences were the three-fold increase of trehalose content associated to the five-fold diminution in glucose concentration in mature galls. Gene expression analysis showed that trehalose accumulation was, at least, partially linked to a significantly lower expression of the trehalase gene in mature galls. Our results point to significant modifications of gall physiology during maturation.

Glutathione is essential for early embryogenesis – Analysis of a glutathione synthetase knockout mouse

Glutathione (GSH) is present in all mammalian tissues and plays a crucial role in many cellular processes. The second and final step in the synthesis involves the formation of GSH from gamma-glutamylcysteine (γ-GC) and glycine and is catalyzed by glutathione synthetase (GS). GS deficiency is a rare autosomal recessive disorder, and is present in patients with a range of phenotypes, from mild hemolytic anemia and metabolic acidosis to severe neurologic disorders or even death in infancy. The substrate for GS, γ-GC, has been suggested as playing a protective role, by substituting for GSH as an antioxidant in GS deficient patients. To examine the role of GS and GSH metabolites in development, we generated mice deficient in GSH by targeted disruption of the GS gene ( Gss). Homozygous mice died before embryonic day (E) 7.5, but heterozygous mice survived with no distinct phenotype. GS protein levels and enzyme activity, as well as GSH metabolites, were investigated in multiple tissues. Protein levels and enzyme activity of GS in heterozygous mice were diminished by 50%, while GSH levels remained intact. γ-GC could not be detected in any investigated tissue. These data demonstrate that GSH is essential for mammalian development, and GSH synthesis via GS is an indispensable pathway for survival.

No metabolites impact in allergic inflammation regulation and their contribution to remodelling bronchi mucous in bronchial asthma patients

Background. To study the role of NO metabolites in allergic inflammation regulation and remodelling in BA patients. Material and methods. Morphological and morphometrical methods of investigation of bronchi mucous of 39 BA patients were used, IL-4, TNF-α, INF-g, IL-8, nitrite, 3-nitrotyrosine, nitrosoglutathion levels in bronchoalveolar washout were investigated, nitrite concentration in condensate of the exhaled air was measured. Results. The increased level of IL-4, TNF-α, INF-g, IL-8 in bronchoalveolar washout is associated with persistent Th2-inflammation. The BA severity correlate with highest IL-8, TNF-a, INF-g, nitrite and 3-nitrotyrosine level but with nitrosoglutathion deficit and in general is associated with structured architectonics bronchi mucous abnormalities. Conclusion. The association of toxic NO metabolites, pro-inflammation cytokines levels, bronchi mucous path-omorphological abnormalities with clinical signs of BA confirms the role of toxic NO metabolites in development of Th2-inflammations.

Effects of beauverolide L and cyclosporin A on humoral and cellular immune response of the greater wax moth, Galleria mellonella

The effects of beauverolide L and cyclosporin A, cyclic peptidic metabolites, produced by several genera of entomopathogenic fungi on immune responses of last instar larvae of the greater wax moth Galleria mellonella have been examined. Intrahemocoelic injection of either metabolite-coated silica particles or dissolved metabolites in a concentrations ranging between 10 and 30 μg per larva caused no mortality but activated humoral responses in G. mellonella larvae. The challenge induced a significant release of lysozyme and cecropin-like activity into the hemolymph, suggesting stimulatory activity on humoral immune responses. Injected metabolite-coated particles were rapidly surrounded by hemocytes which subsequently accomplished formation of melanized nodules, which increased in size and number compared with controls. In vitro assays with dissolved metabolites indicated no adverse effects of beauverolide L or cyclosporin A on attachment or spreading of isolated plasmatocytes but dose-dependent inhibition of their phagocytic activity. Isolated plasmatocytes incubated with cyclosporin A or beauverolide L exhibited cytoskeleton alterations that differed from those observed in plasmatocytes from infected G. mellonella larvae or reported from other fungal secondary metabolites. The experiments provided further data to elucidate the role of fungal secondary metabolites in development of mycoses in insects.