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Circulation. Genomic and Precision... Jun 2024Hypertrophic cardiomyopathy (HCM) is caused by sarcomere gene mutations (genotype-positive HCM) in ≈50% of patients and occurs in the absence of mutations...
Integrating Clinical Phenotype With Multiomics Analyses of Human Cardiac Tissue Unveils Divergent Metabolic Remodeling in Genotype-Positive and Genotype-Negative Patients With Hypertrophic Cardiomyopathy.
BACKGROUND
Hypertrophic cardiomyopathy (HCM) is caused by sarcomere gene mutations (genotype-positive HCM) in ≈50% of patients and occurs in the absence of mutations (genotype-negative HCM) in the other half of patients. We explored how alterations in the metabolomic and lipidomic landscape are involved in cardiac remodeling in both patient groups.
METHODS
We performed proteomics, metabolomics, and lipidomics on myectomy samples (genotype-positive N=19; genotype-negative N=22; and genotype unknown N=6) from clinically well-phenotyped patients with HCM and on cardiac tissue samples from sex- and age-matched and body mass index-matched nonfailing donors (N=20). These data sets were integrated to comprehensively map changes in lipid-handling and energy metabolism pathways. By linking metabolomic and lipidomic data to variability in clinical data, we explored patient group-specific associations between cardiac and metabolic remodeling.
RESULTS
HCM myectomy samples exhibited (1) increased glucose and glycogen metabolism, (2) downregulation of fatty acid oxidation, and (3) reduced ceramide formation and lipid storage. In genotype-negative patients, septal hypertrophy and diastolic dysfunction correlated with lowering of acylcarnitines, redox metabolites, amino acids, pentose phosphate pathway intermediates, purines, and pyrimidines. In contrast, redox metabolites, amino acids, pentose phosphate pathway intermediates, purines, and pyrimidines were positively associated with septal hypertrophy and diastolic impairment in genotype-positive patients.
CONCLUSIONS
We provide novel insights into both general and genotype-specific metabolic changes in HCM. Distinct metabolic alterations underlie cardiac disease progression in genotype-negative and genotype-positive patients with HCM.
Topics: Humans; Cardiomyopathy, Hypertrophic; Male; Female; Middle Aged; Genotype; Adult; Phenotype; Myocardium; Metabolomics; Proteomics; Lipidomics; Lipid Metabolism; Sarcomeres; Energy Metabolism; Aged; Multiomics
PubMed: 38853772
DOI: 10.1161/CIRCGEN.123.004369 -
Water Research Aug 2024Overuse of antibiotics has led to their existence in nitrogen-containing water. The impacts of antibiotics on bio-denitrification and the metabolic response of...
Overuse of antibiotics has led to their existence in nitrogen-containing water. The impacts of antibiotics on bio-denitrification and the metabolic response of denitrifiers to antibiotics are unclear. We systematically analyzed the effect of ciprofloxacin (CIP) on bio-denitrification and found that 5 mg/L CIP greatly inhibited denitrification with a model denitrifier (Paracoccus denitrificans). Nitrate reduction decreased by 32.89 % and nitrous oxide emission increased by 75.53 %. The balance analysis of carbon and nitrogen metabolism during denitrification showed that CIP exposure blocked electron transfer and reduced the flow of substrate metabolism used for denitrification. Proteomics results showed that CIP exposure induced denitrifiers to use the pentose phosphate pathway more for substrate metabolism. This caused a substrate preference to generate NADPH to prevent cellular damage rather than NADH for denitrification. Notably, despite denitrifiers having antioxidant defenses, they could not completely prevent oxidative damage caused by CIP exposure. The effect of CIP exposure on denitrifiers after removal of extracellular polymeric substances (EPS) demonstrated that EPS around denitrifiers formed a barrier against CIP. Fluorescence and infrared spectroscopy revealed that the binding effect of proteins in EPS to CIP prevented damage. This study shows that denitrifiers resist antibiotic stress through different intracellular and extracellular defense strategies.
Topics: Ciprofloxacin; Denitrification; Anti-Bacterial Agents; Paracoccus denitrificans
PubMed: 38851110
DOI: 10.1016/j.watres.2024.121851 -
BMC Plant Biology Jun 2024The phosphorylation of the Light-Harvesting Complex of photosystem II (LHCII) driven by STATE TRANSITION 7 (STN7) kinase is a part of one of the crucial regulatory...
BACKGROUND
The phosphorylation of the Light-Harvesting Complex of photosystem II (LHCII) driven by STATE TRANSITION 7 (STN7) kinase is a part of one of the crucial regulatory mechanisms of photosynthetic light reactions operating in fluctuating environmental conditions, light in particular. There are evidenced that STN7 can also be activated without light as well as in dark-chilling conditions. However, the biochemical mechanism standing behind this complex metabolic pathway has not been deciphered yet.
RESULTS
In this work, we showed that dark-chilling induces light-independent LHCII phosphorylation in runner bean (Phaseolus coccineus L.). In dark-chilling conditions, we registered an increased reduction of the PQ pool which led to activation of STN7 kinase, subsequent LHCII phosphorylation, and possible LHCII relocation inside the thylakoid membrane. We also presented the formation of a complex composed of phosphorylated LHCII and photosystem I typically formed upon light-induced phosphorylation. Moreover, we indicated that the observed steps were preceded by the activation of the oxidative pentose phosphate pathway (OPPP) enzymes and starch accumulation.
CONCLUSIONS
Our results suggest a direct connection between photosynthetic complexes reorganization and dark-chilling-induced activation of the thioredoxin system. The proposed possible pathway starts from the activation of OPPP enzymes and further NADPH-dependent thioredoxin reductase C (NTRC) activation. In the next steps, NTRC simultaneously activates ADP-glucose pyrophosphorylase and thylakoid membrane-located NAD(P)H dehydrogenase-like complex. These results in starch synthesis and electron transfer to the plastoquinone (PQ) pool, respectively. Reduced PQ pool activates STN7 kinase which phosphorylates LHCII. In this work, we present a new perspective on the mechanisms involving photosynthetic complexes while efficiently operating in the darkness. Although we describe the studied pathway in detail, taking into account also the time course of the following steps, the biological significance of this phenomenon remains puzzling.
Topics: Phaseolus; Phosphorylation; Light; Thylakoids; Photosystem I Protein Complex; Cold Temperature; Light-Harvesting Protein Complexes; Photosystem II Protein Complex; Plant Proteins; Starch; Pentose Phosphate Pathway; Enzyme Activation; Photosynthesis; Stress, Physiological; Protein Serine-Threonine Kinases
PubMed: 38849759
DOI: 10.1186/s12870-024-05169-3 -
Free Radical Biology & Medicine Jun 2024The oxidative phase of the pentose phosphate pathway (PPP) involving the enzymes glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphogluconolactonase (6PGL), and...
The oxidative phase of the pentose phosphate pathway (PPP) involving the enzymes glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphogluconolactonase (6PGL), and 6-phosphogluconate dehydrogenase (6PGDH), is critical to NADPH generation within cells, with these enzymes catalyzing the conversion of glucose-6-phosphate (G6P) into ribulose-5-phosphate (Ribu5-P). We have previously studied peroxyl radical (ROO•) mediated oxidative inactivation of E. coli G6PDH, 6PGL, and 6PGDH. However, these data were obtained from experiments where each enzyme was independently exposed to ROO•, a condition not reflecting biological reality. In this work we investigated how NADPH production is modulated when these enzymes are jointly exposed to ROO•. Enzyme mixtures (1:1:1 ratio) were exposed to ROO• produced from thermolysis of 100 mM 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AAPH). NADPH was quantified at 340 nm, and protein oxidation analyzed by liquid chromatography with mass spectrometric detection (LC-MS). The data obtained were rationalized using a mathematical model. The mixture of non-oxidized enzymes, G6P and NADP generated ∼175 μM NADPH. Computational simulations showed a constant decrease of G6P associated with NADPH formation, consistent with experimental data. When the enzyme mixture was exposed to AAPH (3 h, 37 ºC), lower levels of NADPH were detected (∼100 μM) which also fitted with computational simulations. LC-MS analyses indicated modifications at Tyr, Trp, and Met residues but at lower concentrations than detected for the isolated enzymes. Quantification of NADPH generation showed that the pathway activity was not altered during the initial stages of the oxidations, consistent with a buffering role of G6PDH towards inactivation of the oxidative phase of the pathway.
PubMed: 38848786
DOI: 10.1016/j.freeradbiomed.2024.05.050 -
RSC Chemical Biology Jun 2024The account attempts to substantiate the hypothesis that, from an evolutionary perspective, the coenzyme couple pyridoxal phosphate and pyridoxamine phosphate preceded... (Review)
Review
The account attempts to substantiate the hypothesis that, from an evolutionary perspective, the coenzyme couple pyridoxal phosphate and pyridoxamine phosphate preceded the coenzyme thiamine pyrophosphate and acted as its less efficient chemical analogue in some form of early metabolism. The analysis combines mechanism-based chemical reactivity with biosynthetic arguments and provides evidence that vestiges of "TPP-like reactivity" are still found for PLP today. From these thoughts, conclusions can be drawn about the key elements of a primordial form of metabolism, which includes the citric acid cycle, amino acid biosynthesis and the pentose phosphate pathway.
PubMed: 38846080
DOI: 10.1039/d4cb00016a -
Journal of Medicinal Chemistry Jun 2024Building on the preceding structural analysis and a structure-activity relationship (SAR) of 8-aryl-2-hexynyl nucleoside hAAR antagonist , we strategically inverted...
Structural Modification and Biological Evaluation of 2,8-Disubstituted Adenine and Its Nucleosides as A Adenosine Receptor Antagonists: Exploring the Roles of Ribose at Adenosine Receptors.
Building on the preceding structural analysis and a structure-activity relationship (SAR) of 8-aryl-2-hexynyl nucleoside hAAR antagonist , we strategically inverted C2/C8 substituents and eliminated the ribose moiety. These modifications aimed to mitigate potential steric interactions between ribose and adenosine receptors. The SAR findings indicated that such inversions significantly modulated hAAR binding affinities depending on the type of ribose, whereas removal of ribose altered the functional efficacy via hAAR. Among the synthesized derivatives, 2-aryl-8-hexynyl adenine demonstrated the highest selectivity for hAAR ( = 5.0 ± 0.5 nM, / = 86) and effectively blocked cAMP production and restored IL-2 secretion in PBMCs. Favorable pharmacokinetic properties and a notable enhancement of anticancer effects in combination with an mAb immune checkpoint blockade were observed upon oral administration of . These findings establish as a viable immune-oncology therapeutic candidate.
Topics: Humans; Structure-Activity Relationship; Animals; Adenine; Adenosine A2 Receptor Antagonists; Nucleosides; Ribose; Receptor, Adenosine A2A; Mice; Molecular Structure; Rats; Female; Cell Line, Tumor
PubMed: 38845345
DOI: 10.1021/acs.jmedchem.4c01003 -
International Journal of Biological... Jun 2024Mounting an active immune response is energy intensive and demands the reallocation of nutrients to maintain the body's resistance and tolerance against infections.... (Review)
Review
Mounting an active immune response is energy intensive and demands the reallocation of nutrients to maintain the body's resistance and tolerance against infections. Central to this metabolic adaptation is Glucose-6-phosphate dehydrogenase (G6PDH), a housekeeping enzyme involve in pentose phosphate pathway (PPP). PPP play an essential role in generating ribose, which is critical for nicotinamide adenine dinucleotide phosphate (NADPH). It is vital for physiological and cellular processes such as generating nucleotides, fatty acids and reducing oxidative stress. The G6PDH is extremely conserved enzyme across species in PP shunt. The deficiency of enzymes leads to serious consequences on organism, particularly on adaptation and development. Acute deficiency can lead to impaired cell development, halted embryonic growth, reduce sensitivity to insulin, hypertension and increase inflammation. Historically, research focusing on G6PDH and PPP have primarily targeted diseases on mammalian. However, our review has investigated the unique functions of the G6PDH enzyme in insects and greatly improved mechanistic understanding of its operations. This review explore how G6PDH in insects plays a crucial role in managing the redox balance and immune related metabolism. This study aims to investigate the enzyme's role in different metabolic adaptations.
PubMed: 38838892
DOI: 10.1016/j.ijbiomac.2024.132867 -
Bioresource Technology Jul 2024
Topics: Ethanol; Brazil; Xylose; Biofuels; Yeasts; Fermentation
PubMed: 38838833
DOI: 10.1016/j.biortech.2024.130930 -
Bioresource Technology Aug 2024The first comparative pre-treatment study of Miscanthus (Mxg) and sugarcane bagasse (SCB) using steam explosion (SE) and pressurised disc refining (PDR) pretreatment to...
Optimising parameters for pilot scale steam explosion and continuous pressurised disc refining of Miscanthus and sugarcane bagasse for xylose and xylo-oligosaccharide release.
The first comparative pre-treatment study of Miscanthus (Mxg) and sugarcane bagasse (SCB) using steam explosion (SE) and pressurised disc refining (PDR) pretreatment to optimise xylose and xylo-oligosaccharide release is described. The current investigation aimed to 1) Develop optimised batch-wise steam explosion parameters for Mxg and SCB, 2) Scale from static batch steam explosion to dynamic continuous pressurised disc refining, 3) Identify, understand, and circumvent scale-up production hurdles. Optimised SE parameters released 82% (Mxg) and 100% (SCB) of the available xylan. Scaling to PDR, Miscanthus yielded 85% xylan, highlighting how robust scouting assessments for boundary process parameters can result in successful technical transfer. In contrast, SCB technical transfer was not straightforward, with significant differences observed between the two processes, 100% (SE) and 58% (PDR). This report underlines the importance of feedstock-specific pretreatment strategies to underpin process development, scale-up, and optimisation of carbohydrate release from biomass.
Topics: Saccharum; Cellulose; Steam; Xylose; Oligosaccharides; Poaceae; Pilot Projects; Biotechnology; Xylans; Glucuronates
PubMed: 38838831
DOI: 10.1016/j.biortech.2024.130932 -
Carbohydrate Research Jul 2024It is well established that tumour cells undergo metabolic changes to acquire biological advantage over normal cells with activation of the glycolytic pathway, a process...
It is well established that tumour cells undergo metabolic changes to acquire biological advantage over normal cells with activation of the glycolytic pathway, a process termed "Warburg effect". Enzyme isoforms are alternative enzymatic forms with the same function but with different biochemical or epigenetic features. Moreover, isoforms may have varying impacts on different metabolic pathways. We challenge ourselves to analyse the glycolytic and gluconeogenic enzymes and isoforms in breast cancer, a complex and heterogeneous pathology, associated with high incidence and mortality rates especially among women. We analysed epithelial and tumour cell lines by RT-PCR and compared values to a publicly available database for the expression profile of normal and tumour tissues (Gepia) of enzymes and enzymatic isoforms from glycolytic and gluconeogenic pathways. Additionally, GeneMANIA was used to evaluate interactions, pathways, and attributes of each glycolytic/gluconeogenic steps. The findings reveal that the enzymes and enzymatic isoforms expressed in cell culture were somewhat different from those in breast tissue. We propose that the tumor microenvironment plays a crucial role in the expression of glycolytic and gluconeogenic enzymes and isoforms in tumour cells. Nonetheless, they not only participate in glycolytic and gluconeogenic enzymatic activities but may also influence other pathways, such as the Pentose-Phosphate-Pathway, TCA cycle, as well as other carbohydrate, lipid, and amino acid metabolism.
Topics: Humans; Breast Neoplasms; Gluconeogenesis; Female; Glycolysis; Cell Line, Tumor; Isoenzymes
PubMed: 38838492
DOI: 10.1016/j.carres.2024.109169