Search Results (18)

Nymphs of the ambar mutant of Orius laevigatus (Fieber) are orange-colored instead of the yellowish color of the wild-type individuals. Since there were no previous studies of the pigments of this species, we searched for differences in pigments of the pteridine family between both strains. Fluorescent compounds from nymph extracts were separated by cellulose thin-layer chromatography (TLC) and by size exclusion chromatography, followed by LC/MS/MS. The present study has allowed the identification for the first time in O. laevigatus of erythropterin, leucopterin, 7-methylxanthopterin, xanthopterin, isoxanthopterin, pterin, and biopterin. The quantification was performed by fluorometry after elution of the pteridines previously separated by TLC. The results showed that the orange color in the ambar nymphs was due to the accumulation of the orange pigment erythropterin. Additionally, mutant nymphs exhibited significantly elevated levels of pterin and reduced levels of leucopterin. The possibility that these differences were due to differences in xanthine dehydrogenase (XDH) activity was tested; the results indicated that XDH deficiency is unlikely to be responsible for the mutant phenotype. Considering that the ambar mutation is recessive, the mutant phenotype should, most likely, be due to a disruption in downstream metabolic steps involved in erythropterin processing. Full article

Sepiapterin Reductase Deficiency (SRD) is a rare inherited neurometabolic disorder caused by variants in the SPR gene, which may lead to developmental delays, psychomotor retardation, and cognitive impairments. Two consanguineous North African and Middle Eastern families are reported with multiple affected individuals presenting with developmental delay, ataxia, hypotonia, fatigue, and ptosis, or parkinsonism and cognitive impairment. Exome sequencing revealed a novel homozygous SPR c.560A>G (p.Glu187Gly) mutation that segregates with disease. According to molecular dynamics analysis, the substitution is predicted to compromise structural integrity, likely affecting ligand binding and catalytic activity. Elevated cerebrospinal fluid sepiapterin and biopterin levels, along with low neurotransmitter levels, were concordant with a genetic diagnosis of SRD and the reclassification of this variant as pathogenic. SRD patients manifest a broad constellation of symptoms, albeit well-managed using low-dose L-dopa/carbidopa. This study highlights the value of genetic testing in expediting early diagnosis and intervention to mitigate the onset of this disorder. Full article

Background/Objectives: Particulate matter (PM) is a primary health hazard associated with metabolic pathway disruption. Population characteristics, topography, sources, and PM components contribute to health impacts. Methods: In this study, NMR-based metabolomics was used to evaluate the health impacts of prolonged exposure to PM. Blood samples (n = 197) were collected from healthy volunteers in low- (control; CG) and high-exposure areas (exposure; EG) in Northern Thailand. Non-targeted metabolite analysis was performed using proton nuclear magnetic resonance spectroscopy (¹H-NMR). Results: Compared to CG, EG showed significantly increased levels of dopamine, N6-methyladenosine, 3-hydroxyproline, 5-carboxylcytosine, and cytidine (p < 0.05), while biopterin, adenosine, L-Histidine, epinephrine, and norepinephrine were significantly higher in CG (p < 0.05). These metabolic disturbances suggest that chronic exposure to particulate matter (PM) impairs energy and amino acid metabolism while enhancing oxidative stress, potentially contributing to the onset of non-communicable diseases (NCDs) such as cancer and neurodegenerative conditions. Conclusions: This study highlighted the connection between sub-chronic PM2.5 exposure, metabolic disturbances, and an increased risk of non-communicable diseases (NCDs), stressing the critical need for effective PM2.5 reduction strategies in Northern Thailand. Full article

Lead (Pb) is a heavy metal associated with a range of toxic effects. Relatively few studies attempt to understand the impact of lead on development from a mechanistic perspective. Danio rerio (zebrafish) embryos are a model organism for studying the developmental consequences of exposure to chemical agents. This study examined the metabolome of developing zebrafish embryos exposed to 5 ppb, 15 ppb, 150 ppb, and 1500 ppb Pb concentrations during the first 24 h post fertilization, followed by 24 h of unexposed development and harvest at 48 h. Untargeted metabolomics and multivariate analysis revealed that various Pb exposures differentially affected the embryonic metabolome. Pathway analyses showed the dysregulation of biopterin, purine, alanine, and aspartate metabolism. Inductively coupled plasma mass spectrometry demonstrated Pb accumulation in embryos. Additionally, decreases in oxidation–reduction ratios were observed in 5–150 ppb groups but not in the 1500 ppb exposure group. This finding, along with several metabolite abundances, suggests a hormetic effect of Pb concentrations on the developing zebrafish metabolome. Together, these data reveal persistent global changes in the embryonic metabolome, pin-point biomarkers for Pb exposure, unveil dose-dependent relationships, and reflect Pb-induced changes in cellular energy. This work highlights aberrant processes and persistent changes underlying low-dose heavy metal exposure during early development. Full article

Background/Objectives: As COVID-19 can be severe, early predictive markers of both severity and onset of secondary bacterial infections are needed. This study first examined changes over time in the levels of plasma neopterin (NP) and biopterins (BPs), among others, in patients with COVID-19 and then in those with secondary bacterial infection complications. Methods: Fifty-two patients with COVID-19 admitted to two tertiary care centers were included. They were divided into a severe group (intubated + mechanical ventilation) (n = 10) and a moderate group (non-intubated + oxygen administration) (n = 42), and changes over time in plasma NP, plasma BPs, IFN-γ, lymphocyte count, CRP, and IL-6 were investigated. Four of the patients in the severe group (n = 10) developed secondary bacterial infections during treatment. Plasma NP and plasma BPs of patients with bacterial sepsis (no viral infection) (n = 25) were also examined. Results: The plasma NP, IL-6, CRP, and SOFA levels were significantly higher in the severe group, while the IFN-γ level and lymphocyte count were significantly lower. The higher plasma NP in the severe group persisted only up to 1 week after symptom onset. The plasma BPs were higher in complications of bacterial infection. Conclusions: The timing of sample collection is important for assessing severity through plasma NP, while plasma BPs may be a useful diagnostic tool for identifying the development of secondary bacterial infection in patients with COVID-19. Further investigation is needed to clarify the mechanism by which NP and BPs, which are involved in the same biosynthetic pathway, are differentially activated depending on the type of pathogen. Full article

DNAJC12-deficient hyperphenylalaninemia is a recently described inborn error of metabolism associated with hyperphenylalaninemia, neurotransmitter deficiency, and developmental delay caused by biallelic pathogenic variants of the DNAJC12 gene. The loss of the DNAJC12-encoded chaperone results in the destabilization of the biopterin-dependent aromatic amino acid hydroxylases, resulting in deficiencies in dopamine, norepinephrine, and serotonin. We present the case of a patient who screened positive for hyperphenylalaninemia on newborn screening and was discovered to be homozygous for a likely pathogenic variant of DNAJC12. Here, we review the management of DNAJC12-related hyperphenylalaninemia and compare our patient to other reported cases in the literature to investigate how early detection and management may impact clinical outcomes. Full article

Background: Atherosclerosis (AS) is a chronic progressive disease caused by lipometabolic disorder. However, the pathological characteristics and mechanism of AS have not been fully clarified. Through high-fat and high-cholesterol diet induction, Tibetan minipigs can be used as the AS model animals, as they have a very similar AS pathogenesis to humans. Methods: In this study, we built an AS model of Tibetan minipigs and identified the differential abundance metabolites in the development of AS based on untargeted metabolomics. Results: We found that sphingolipid metabolism and glucose oxidation were obviously higher in the AS group and phenylalanine metabolism was reduced in the AS group. Moreover, in the development of AS, gluconolactone was enriched in the late stage of AS whereas biopterin was enriched in the early stage of AS. Conclusions: Our research provides novel clues to investigate the metabolic mechanism of AS from the perspective of metabolomics. Full article

Endothelial dysfunction result from inflammation and excessive production of reactive oxygen species as part of the surgical stress response. Remote ischemic preconditioning (RIPC) potentially exerts anti-oxidative and anti-inflammatory properties, which might stabilise the endothelial function after non-cardiac surgery. This was a single centre randomised clinical trial including 60 patients undergoing sub-acute laparoscopic cholecystectomy due to acute cholecystitis. Patients were randomised to RIPC or control. The RIPC procedure consisted of four cycles of five minutes of ischaemia and reperfusion of one upper extremity. Endothelial function was assessed as the reactive hyperaemia index (RHI) and circulating biomarkers of nitric oxide (NO) bioavailability (L-arginine, asymmetric dimethylarginine (ADMA), L-arginine/ADMA ratio, tetra- and dihydrobiopterin (BH₄ and BH₂), and total plasma biopterin) preoperative, 2–4 h after surgery and 24 h after surgery. RHI did not differ between the groups (p = 0.07). Neither did levels of circulating biomarkers of NO bioavailability change in response to RIPC. L-arginine and L-arginine/ADMA ratio was suppressed preoperatively and increased 24 h after surgery (p < 0.001). The BH₄/BH₂-ratio had a high preoperative level, decreased 2–4 h after surgery and remained low 24 h after surgery (p = 0.01). RIPC did not influence endothelial function or markers of NO bioavailability until 24 h after sub-acute laparoscopic cholecystectomy. In response to surgery, markers of NO bioavailability increased, and oxidative stress decreased. These findings support that a minimally invasive removal of the inflamed gallbladder countereffects reduced markers of NO bioavailability and increased oxidative stress caused by acute cholecystitis. Full article

We hypothesized that patients with chronic kidney disease (CKD) display an altered plasma amino acid (AA) metabolomic profile that could contribute to abnormal vascular maintenance of peripheral circulation in uremia. The relationships between plasma AAs and endothelial and vascular smooth muscle function in the microcirculation of CKD patients are not well understood. The objective of this study is to investigate to what extent the levels of AAs and its metabolites are changed in CKD patients and to test their relationship with endothelial and vascular smooth muscle function. Patients with CKD stages 3 and 5 and non-CKD controls are included in this study. We report that there was a significant reduction of the biopterin (BH₄/BH₂) ratio, which was accompanied by increased plasma levels of BH₂, asymmetric dimethylarginine (ADMA) and citrulline in patients with CKD-5 vs. CKD-3 vs. controls. In vivo augmentation index measurement showed a positive association with ADMA in all participants. The contribution of nitric oxide, assessed by ex vivo assay, showed a negative association with creatinine, ADMA and citrulline in all participants. In CKD-5, BH₄ negatively correlated with ADMA and ornithine levels, and the ex vivo endothelium-mediated dilatation positively correlated with phenylalanine levels. In conclusion, uremia is associated with alterations in AA metabolism that may affect endothelium-dependent dilatation and vascular stiffness in microcirculation. Interventional strategies aiming to normalize the AA metabolism could be of interest as treatment options. Full article

Butyrate, a short-chain fatty acid, is utilized by the gut epithelium as energy and it improves the gut epithelial barrier. More recently, it has been associated with beneficial effects on immune and cardiovascular homeostasis. Conversely, tumor necrosis factor alpha (TNFα) is a pro-inflammatory and pro-hypertensive cytokine. While butyrate and TNFα are both linked with hypertension, studies have not yet addressed their interaction in the colon. Here, we investigated the capacity of butyrate to modulate a host of effects of TNFα in primary rodent colonic cells in vitro. We measured ATP levels, cell viability, mitochondrial membrane potential (MMP), reactive oxygen species (ROS), mitochondrial oxidative phosphorylation, and glycolytic activity in colonocytes following exposure to either butyrate or TNFα, or both. To address the potential mechanisms, transcripts related to oxidative stress, cell fate, and cell metabolism (Pdk1, Pdk2, Pdk4, Spr, Slc16a1, Slc16a3, Ppargc1a, Cs, Lgr5, Casp3, Tnfr2, Bax, Bcl2, Sod1, Sod2, and Cat) were measured, and untargeted liquid chromatography–tandem mass spectrometry (LC-MS/MS) was employed to profile the metabolic responses of colonocytes following exposure to butyrate and TNFα. We found that both butyrate and TNFα lowered cellular ATP levels towards a quiescent cell energy phenotype, characterized by decreased oxygen consumption and extracellular acidification. Co-treatment with butyrate ameliorated TNFα-induced cytotoxicity and the reduction in cell viability. Butyrate also opposed the TNFα-mediated decrease in MMP and mitochondrial-to-intracellular calcium ratios, suggesting that butyrate may protect colonocytes against TNFα-induced cytotoxicity by decreasing mitochondrial calcium flux. The relative expression levels of pyruvate dehydrogenase kinase 4 (Pdk4) were increased via co-treatment of butyrate and TNFα, suggesting the synergistic inhibition of glycolysis. TNFα alone reduced the expression of monocarboxylate transporters slc16a1 and slc16a3, suggesting effects of TNFα on butyrate uptake into colonocytes. Of the 185 metabolites that were detected with LC-MS, the TNFα-induced increase in biopterin produced the only significant change, suggesting an alteration in mitochondrial biogenesis in colonocytes. Considering the reports of elevated colonic TNFα and reduced butyrate metabolism in many conditions, including in hypertension, the present work sheds light on cellular interactions between TNFα and butyrate in colonocytes that may be important in understanding conditions of the colon. Full article

Melanoma is the most aggressive type of skin cancer due to its high capability of developing metastasis and acquiring chemoresistance. Altered redox homeostasis induced by increased reactive oxygen species is associated with melanomagenesis through modulation of redox signaling pathways. Dysfunctional endothelial nitric oxide synthase (eNOS) produces superoxide anion (O₂^−•) and contributes to the establishment of a pro-oxidant environment in melanoma. Although decreased tetrahydrobiopterin (BH4) bioavailability is associated with eNOS uncoupling in endothelial and human melanoma cells, in the present work we show that eNOS uncoupling in metastatic melanoma cells expressing the genes from de novo biopterin synthesis pathway Gch1, Pts, and Spr, and high BH4 concentration and BH4:BH2 ratio. Western blot analysis showed increased expression of Nos3, altering the stoichiometry balance between eNOS and BH4, contributing to NOS uncoupling. Both treatment with L-sepiapterin and eNOS downregulation induced increased nitric oxide (NO) and decreased O₂^• levels, triggering NOS coupling and reducing cell growth and resistance to anoikis and dacarbazine chemotherapy. Moreover, restoration of eNOS activity impaired tumor growth in vivo. Finally, NOS3 expression was found to be increased in human metastatic melanoma samples compared with the primary site. eNOS dysfunction may be an important mechanism supporting metastatic melanoma growth and hence a potential target for therapy. Full article

Acute liver failure (ALF) is associated with deregulated nitric oxide (NO) signaling in the brain, which is one of the key molecular abnormalities leading to the neuropsychiatric disorder called hepatic encephalopathy (HE). This study focuses on the effect of ALF on the relatively unexplored endothelial NOS isoform (eNOS). The cerebral prefrontal cortices of rats with thioacetamide (TAA)-induced ALF showed decreased eNOS expression, which resulted in an overall reduction of NOS activity. ALF also decreased the content of the NOS cofactor, tetrahydro-L-biopterin (BH4), and evoked eNOS uncoupling (reduction of the eNOS dimer/monomer ratio). The addition of the NO precursor L-arginine in the absence of BH4 potentiated ROS accumulation, whereas nonspecific NOS inhibitor L-NAME or EDTA attenuated ROS increase. The ALF-induced decrease of eNOS content and its uncoupling concurred with, and was likely causally related to, both increased brain content of reactive oxidative species (ROS) and decreased cerebral cortical blood flow (CBF) in the same model. Full article

While numerous genomes of Leishmania spp. have been sequenced and analyzed, an understanding of the evolutionary history of these organisms remains limited due to the unavailability of the sequence data for their closest known relatives, Endotrypanum and Porcisia spp., infecting sloths and porcupines. We have sequenced and analyzed genomes of three members of this clade in order to fill this gap. Their comparative analyses revealed only minute differences from Leishmaniamajor genome in terms of metabolic capacities. We also documented that the number of genes under positive selection on the Endotrypanum/Porcisia branch is rather small, with the flagellum-related group of genes being over-represented. Most significantly, the analysis of gene family evolution revealed a substantially reduced repertoire of surface proteins, such as amastins and biopterin transporters BT1 in the Endotrypanum/Porcisia species when compared to amastigote-dwelling Leishmania. This reduction was especially pronounced for δ-amastins, a subfamily of cell surface proteins crucial in the propagation of Leishmania amastigotes inside vertebrate macrophages and, apparently, dispensable for Endotrypanum/Porcisia, which do not infect such cells. Full article

In fish, sperm motility activation is one of the most essential procedures for fertilization. Previous studies have mainly focused on the external environmental effects and intracellular signals in sperm activation; however, little is known about the metabolic process of sperm motility activation in fish. In the present study, using ricefield eel (Monopterus albus) sperm as a model, metabonomics was used to analyze the metabolic mechanism of the sperm motility activation in fish. Firstly, 529 metabolites were identified in the sperm of ricefield eel, which were clustered into the organic acids, amino acids, nucleotides, benzene, and carbohydrates, respectively. Among them, the most abundant metabolites in sperm were L-phenylalanine, DL-leucine, L-leucine, lysolecithin choline 18:0, L-tryptophan, adenine, hypoxanthine, 7-Methylguanine, shikimic acid, and L-tyrosine. Secondly, compared to pre-activated sperm, the level of S-sulfo-L-cysteine and L-asparagine were both increased in the post-activated sperm. Ninety-two metabolites were decreased in the post-activated sperm, including quinic acid, acetylsalicylic acid, 7,8-dihydro L-biopterin, citric acid, glycylphenylalanine, and dihydrotachysterol (DHT). Finally, basing on the pathway analysis, we found that the changed metabolites in sperm motility activation were mainly clustered into energy metabolism and anti-oxidative stress. Fish sperm motility activation would be accompanied by the release of a large amount of energy, which might damage the genetic material of sperm. Thus, the anti-oxidative stress function is a critical process to maintain the normal physiological function of sperm. Full article

Peripheral artery disease (PAD) pathophysiology extends beyond hemodynamics to include other operating mechanisms, including endothelial dysfunction. Oxidative stress may be linked to endothelial dysfunction by reducing nitric oxide (NO) bioavailability. We aimed to investigate whether the NO system and its regulators are altered in the setting of PAD and to assess the relationship between NO bioavailability and oxidative stress. Sera from 35 patients with intermittent claudication (IC), 26 patients with critical limb ischemia (CLI), and 35 non-PAD controls were analyzed to determine levels of tetrahydrobiopterin (BH4), dihydrobiopterin (BH2), nitrate/nitrite (nitric oxides, or NOx), arginine, citrulline, asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and the oxidative stress markers 8-Oxo-2′-deoxyguanosine (8-OHdG), 4-hydroxynonenal (4-HNE), advanced glycation end products (AGEs), and protein carbonyls. NOx was significantly lower in IC and CLI patients compared to controls in association with elevated oxidative stress, with the greatest NOx reductions observed in CLI. Compared with controls, IC and CLI patients had reduced BH4, elevated BH2, and a reduced BH4/BH2 ratio. SDMA, the arginine/SDMA ratio, and the arginine/ADMA ratio were significantly higher in CLI patients. The NO system and its regulators are significantly compromised in PAD. This dysregulation appears to be driven by increased oxidative stress and worsens as the disease progresses from claudication to CLI. Full article