RESUMEN
Here, we describe the identification of an antibiotic class acting via LpxH, a clinically unexploited target in lipopolysaccharide synthesis. The lipopolysaccharide synthesis pathway is essential in most Gram-negative bacteria and there is no analogous pathway in humans. Based on a series of phenotypic screens, we identified a hit targeting this pathway that had activity on efflux-defective strains of Escherichia coli. We recognized common structural elements between this hit and a previously published inhibitor, also with activity against efflux-deficient bacteria. With the help of X-ray structures, this information was used to design inhibitors with activity on efflux-proficient, wild-type strains. Optimization of properties such as solubility, metabolic stability and serum protein binding resulted in compounds having potent in vivo efficacy against bloodstream infections caused by the critical Gram-negative pathogens E. coli and Klebsiella pneumoniae. Other favorable properties of the series include a lack of pre-existing resistance in clinical isolates, and no loss of activity against strains expressing extended-spectrum-ß-lactamase, metallo-ß-lactamase, or carbapenemase-resistance genes. Further development of this class of antibiotics could make an important contribution to the ongoing struggle against antibiotic resistance.
Asunto(s)
Antibacterianos , Lipopolisacáridos , Humanos , Antibacterianos/química , Escherichia coli/metabolismo , Bacterias Gramnegativas/metabolismo , beta-Lactamasas/genética , Pruebas de Sensibilidad MicrobianaRESUMEN
Acylcarnitines are fatty acid metabolites that play important roles in many cellular energy metabolism pathways. They have historically been used as important diagnostic markers for inborn errors of fatty acid oxidation and are being intensively studied as markers of energy metabolism, deficits in mitochondrial and peroxisomal ß -oxidation activity, insulin resistance, and physical activity. Acylcarnitines are increasingly being identified as important indicators in metabolic studies of many diseases, including metabolic disorders, cardiovascular diseases, diabetes, depression, neurologic disorders, and certain cancers. The US Food and Drug Administration-approved drug L-carnitine, along with short-chain acylcarnitines (acetylcarnitine and propionylcarnitine), is now widely used as a dietary supplement. In light of their growing importance, we have undertaken an extensive review of acylcarnitines and provided a detailed description of their identity, nomenclature, classification, biochemistry, pathophysiology, supplementary use, potential drug targets, and clinical trials. We also summarize these updates in the Human Metabolome Database, which now includes information on the structures, chemical formulae, chemical/spectral properties, descriptions, and pathways for 1240 acylcarnitines. This work lays a solid foundation for identifying, characterizing, and understanding acylcarnitines in human biosamples. We also discuss the emerging opportunities for using acylcarnitines as biomarkers and as dietary interventions or supplements for many wide-ranging indications. The opportunity to identify new drug targets involved in controlling acylcarnitine levels is also discussed. SIGNIFICANCE STATEMENT: This review provides a comprehensive overview of acylcarnitines, including their nomenclature, structure and biochemistry, and use as disease biomarkers and pharmaceutical agents. We present updated information contained in the Human Metabolome Database website as well as substantial mapping of the known biochemical pathways associated with acylcarnitines, thereby providing a strong foundation for further clarification of their physiological roles.
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Carnitina , Resistencia a la Insulina , Biomarcadores , Carnitina/análogos & derivados , Carnitina/química , Carnitina/metabolismo , Carnitina/uso terapéutico , Ácidos Grasos/metabolismo , Humanos , Resistencia a la Insulina/fisiologíaRESUMEN
Post-acute sequelae of COVID-19 can present as multi-organ pathology, with neuropsychiatric symptoms being the most common symptom complex, characterizing long COVID as a syndrome with a significant disease burden for affected individuals. Several typical symptoms of long COVID, such as fatigue, depressive symptoms and cognitive impairment, are also key features of other psychiatric disorders such as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and major depressive disorder (MDD). However, clinically successful treatment strategies are still lacking and are often inspired by treatment options for diseases with similar clinical presentations, such as ME/CFS. Acetylcarnitine, the shortest metabolite of a class of fatty acid metabolites called acylcarnitines and one of the most abundant blood metabolites in humans can be used as a dietary/nutritional supplement with proven clinical efficacy in the treatment of MDD, ME/CFS and other neuropsychiatric disorders. Basic research in recent decades has established acylcarnitines in general, and acetylcarnitine in particular, as important regulators and indicators of mitochondrial function and other physiological processes such as neuroinflammation and energy production pathways. In this review, we will compare the clinical basis of neuropsychiatric long COVID with other fatigue-associated diseases. We will also review common molecular disease mechanisms associated with altered acetylcarnitine metabolism and the potential of acetylcarnitine to interfere with these as a therapeutic agent. Finally, we will review the current evidence for acetylcarnitine as a supplement in the treatment of fatigue-associated diseases and propose future research strategies to investigate the potential of acetylcarnitine as a treatment option for long COVID.
RESUMEN
Heart-type fatty-acid binding protein (FABP3) is an essential cytosolic lipid transport protein found in cardiomyocytes. FABP3 binds fatty acids (FAs) reversibly and with high affinity. Acylcarnitines (ACs) are an esterified form of FAs that play an important role in cellular energy metabolism. However, an increased concentration of ACs can exert detrimental effects on cardiac mitochondria and lead to severe cardiac damage. In the present study, we evaluated the ability of FABP3 to bind long-chain ACs (LCACs) and protect cells from their harmful effects. We characterized the novel binding mechanism between FABP3 and LCACs by a cytotoxicity assay, nuclear magnetic resonance, and isothermal titration calorimetry. Our data demonstrate that FABP3 is capable of binding both FAs and LCACs as well as decreasing the cytotoxicity of LCACs. Our findings reveal that LCACs and FAs compete for the binding site of FABP3. Thus, the protective mechanism of FABP3 is found to be concentration dependent.
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Proteínas de Unión a Ácidos Grasos , Ácidos Grasos , Proteína 3 de Unión a Ácidos Grasos/metabolismo , Proteínas de Unión a Ácidos Grasos/metabolismo , Ácidos Grasos/farmacología , Carnitina , Miocitos Cardíacos/metabolismoRESUMEN
The accumulation of lipid intermediates may interfere with energy metabolism pathways and regulate cellular energy supplies. As increased levels of long-chain acylcarnitines have been linked to insulin resistance, we investigated the effects of long-chain acylcarnitines on key components of the insulin signalling pathway. We discovered that palmitoylcarnitine induces dephosphorylation of the insulin receptor (InsR) through increased activity of protein tyrosine phosphatase 1B (PTP1B). Palmitoylcarnitine suppresses protein kinase B (Akt) phosphorylation at Ser473, and this effect is not alleviated by the inhibition of PTP1B by the insulin sensitizer bis-(maltolato)-oxovanadium (IV). This result indicates that palmitoylcarnitine affects Akt activity independently of the InsR phosphorylation level. Inhibition of protein kinase C and protein phosphatase 2A does not affect the palmitoylcarnitine-mediated inhibition of Akt Ser473 phosphorylation. Additionally, palmitoylcarnitine markedly stimulates insulin release by suppressing Akt Ser473 phosphorylation in insulin-secreting RIN5F cells. In conclusion, long-chain acylcarnitines activate PTP1B and decrease InsR Tyr1151 phosphorylation and Akt Ser473 phosphorylation, thus limiting the cellular response to insulin stimulation.
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Carnitina/análogos & derivados , Fosforilación/efectos de los fármacos , Proteína Tirosina Fosfatasa no Receptora Tipo 1/metabolismo , Receptor de Insulina/metabolismo , Tirosina/metabolismo , Animales , Células CHO , Carnitina/farmacología , Cricetulus , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Insulina/metabolismo , Resistencia a la Insulina , Modelos Biológicos , Proteína Fosfatasa 2/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Receptor de Insulina/químicaRESUMEN
Right ventricular (RV) and left ventricular (LV) dysfunction is common in a significant number of hospitalized coronavirus disease 2019 (COVID-19) patients. This study was conducted to assess whether the improved mitochondrial bioenergetics by cardiometabolic drug meldonium can attenuate the development of ventricular dysfunction in experimental RV and LV dysfunction models, which resemble ventricular dysfunction in COVID-19 patients. Effects of meldonium were assessed in rats with pulmonary hypertension-induced RV failure and in mice with inflammation-induced LV dysfunction. Rats with RV failure showed decreased RV fractional area change (RVFAC) and hypertrophy. Treatment with meldonium attenuated the development of RV hypertrophy and increased RVFAC by 50%. Mice with inflammation-induced LV dysfunction had decreased LV ejection fraction (LVEF) by 30%. Treatment with meldonium prevented the decrease in LVEF. A decrease in the mitochondrial fatty acid oxidation with a concomitant increase in pyruvate metabolism was noted in the cardiac fibers of the rats and mice with RV and LV failure, respectively. Meldonium treatment in both models restored mitochondrial bioenergetics. The results show that meldonium treatment prevents the development of RV and LV systolic dysfunction by enhancing mitochondrial function in experimental models of ventricular dysfunction that resembles cardiovascular complications in COVID-19 patients.
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Cardiotónicos/farmacología , Metilhidrazinas/farmacología , Animales , COVID-19/complicaciones , Cardiotónicos/uso terapéutico , Cardiotoxicidad/tratamiento farmacológico , Modelos Animales de Enfermedad , Endotelio/efectos de los fármacos , Insuficiencia Cardíaca/tratamiento farmacológico , Insuficiencia Cardíaca/metabolismo , Ventrículos Cardíacos/efectos de los fármacos , Peróxido de Hidrógeno/metabolismo , Pulmón/efectos de los fármacos , Masculino , Metilhidrazinas/uso terapéutico , Ratones Endogámicos C57BL , Mitocondrias/efectos de los fármacos , Saturación de Oxígeno/efectos de los fármacos , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismo , Daño por Reperfusión/tratamiento farmacológico , Volumen Sistólico/efectos de los fármacos , Disfunción Ventricular Izquierda/tratamiento farmacológico , Disfunción Ventricular Derecha/tratamiento farmacológico , Tratamiento Farmacológico de COVID-19RESUMEN
The suppression of energy metabolism is one of cornerstones of cardiac dysfunction in sepsis/endotoxaemia. To investigate the role of fatty acid oxidation (FAO) in the progression of inflammation-induced cardiac dysfunction, we compared the effects of FAO-targeting compounds on mitochondrial and cardiac function in an experimental model of lipopolysaccharide (LPS)-induced endotoxaemia. In LPS-treated mice, endotoxaemia-induced inflammation significantly decreased cardiac FAO and increased pyruvate metabolism, while cardiac mechanical function was decreased. AMP-activated protein kinase activation by A769662 improved mitochondrial FAO without affecting cardiac function and inflammation-related gene expression during endotoxaemia. Fatty acid synthase inhibition by C75 restored both cardiac and mitochondrial FAO; however, no effects on inflammation-related gene expression and cardiac function were observed. In addition, the inhibition of carnitine palmitoyltransferase 2 (CPT2)-dependent FAO by aminocarnitine resulted in the accumulation of FAO intermediates, long-chain acylcarnitines, in the heart. As a result, cardiac pyruvate metabolism was inhibited, which further exacerbated inflammation-induced cardiac dysfunction. In conclusion, although inhibition of CPT2-dependent FAO is detrimental to cardiac function during endotoxaemia, present findings show that the restoration of cardiac FAO alone is not sufficient to recover cardiac function. Rescue of cardiac FAO should be combined with anti-inflammatory therapy to ameliorate cardiac dysfunction in endotoxaemia.
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Carnitina O-Palmitoiltransferasa/antagonistas & inhibidores , Progresión de la Enfermedad , Endotoxemia/enzimología , Endotoxemia/fisiopatología , Corazón/fisiopatología , Inflamación/enzimología , Inflamación/patología , Animales , Biomarcadores/sangre , Glucemia/metabolismo , Temperatura Corporal , Carnitina O-Palmitoiltransferasa/metabolismo , Endotoxemia/sangre , Metabolismo Energético , Ácidos Grasos/metabolismo , Femenino , Inflamación/sangre , Inflamación/complicaciones , Lipopolisacáridos , Ratones , Mitocondrias Cardíacas/metabolismoRESUMEN
Reducing infarct size during a cardiac ischaemic-reperfusion episode is still of paramount importance, because the extension of myocardial necrosis is an important risk factor for developing heart failure. Cardiac ischaemia-reperfusion injury (IRI) is in principle a metabolic pathology as it is caused by abruptly halted metabolism during the ischaemic episode and exacerbated by sudden restart of specific metabolic pathways at reperfusion. It should therefore not come as a surprise that therapy directed at metabolic pathways can modulate IRI. Here, we summarize the current knowledge of important metabolic pathways as therapeutic targets to combat cardiac IRI. Activating metabolic pathways such as glycolysis (eg AMPK activators), glucose oxidation (activating pyruvate dehydrogenase complex), ketone oxidation (increasing ketone plasma levels), hexosamine biosynthesis pathway (O-GlcNAcylation; administration of glucosamine/glutamine) and deacetylation (activating sirtuins 1 or 3; administration of NAD+ -boosting compounds) all seem to hold promise to reduce acute IRI. In contrast, some metabolic pathways may offer protection through diminished activity. These pathways comprise the malate-aspartate shuttle (in need of novel specific reversible inhibitors), mitochondrial oxygen consumption, fatty acid oxidation (CD36 inhibitors, malonyl-CoA decarboxylase inhibitors) and mitochondrial succinate metabolism (malonate). Additionally, protecting the cristae structure of the mitochondria during IR, by maintaining the association of hexokinase II or creatine kinase with mitochondria, or inhibiting destabilization of FO F1 -ATPase dimers, prevents mitochondrial damage and thereby reduces cardiac IRI. Currently, the most promising and druggable metabolic therapy against cardiac IRI seems to be the singular or combined targeting of glycolysis, O-GlcNAcylation and metabolism of ketones, fatty acids and succinate.
Asunto(s)
Terapia Molecular Dirigida , Infarto del Miocardio/metabolismo , Miocardio/metabolismo , Animales , Metabolismo Energético , Humanos , Mitocondrias Cardíacas/metabolismo , Daño por Reperfusión Miocárdica/metabolismo , Miocardio/patologíaRESUMEN
PURPOSE: Sodium-glucose cotransporter 2 (SGLT2) inhibitors prevent heart failure and decrease cardiovascular mortality in patients with type 2 diabetes. Heart failure is associated with detrimental changes in energy metabolism, and the preservation of cardiac mitochondrial function is crucial for the failing heart. However, to date, there are no data to support the hypothesis that treatment with a SGLT2 inhibitor might alter mitochondrial bioenergetics in diabetic failing hearts. Thus, the aim of this study was to investigate the protective effects of empagliflozin on mitochondrial fatty acid metabolism. METHODS: Mitochondrial dysfunction was induced by 18 weeks of high-fat diet (HFD)-induced lipid overload. Empagliflozin was administered at a dose of 10 mg/kg in a chow for 18 weeks. Palmitate metabolism in vivo, cardiac mitochondrial functionality and biochemical parameters were measured. RESULTS: In HFD-fed mice, palmitate uptake was 1.7, 2.3, and 1.9 times lower in the heart, liver, and kidneys, respectively, compared with that of the normal chow control group. Treatment with empagliflozin increased palmitate uptake and decreased the accumulation of metabolites of incomplete fatty acid oxidation in cardiac tissues, but not other tissues, compared with those of the HFD control group. Moreover, empagliflozin treatment resulted in fully restored fatty acid oxidation pathway-dependent respiration in permeabilized cardiac fibers. Treatment with empagliflozin did not affect the biochemical parameters related to hyperglycemia or hyperlipidemia. CONCLUSION: Empagliflozin treatment preserves mitochondrial fatty acid oxidation in the heart under conditions of chronic lipid overload.
Asunto(s)
Compuestos de Bencidrilo/farmacología , Dieta Alta en Grasa , Dislipidemias/tratamiento farmacológico , Metabolismo Energético/efectos de los fármacos , Glucósidos/farmacología , Mitocondrias Cardíacas/efectos de los fármacos , Palmitatos/metabolismo , Inhibidores del Cotransportador de Sodio-Glucosa 2/farmacología , Animales , Modelos Animales de Enfermedad , Dislipidemias/etiología , Dislipidemias/metabolismo , Masculino , Ratones Endogámicos C57BL , Mitocondrias Cardíacas/metabolismo , Oxidación-ReducciónRESUMEN
The accumulation of long-chain fatty acids (FAs) and their CoA and carnitine esters is observed in the ischaemic myocardium after acute ischaemia/reperfusion. The aim of the present study was to identify harmful FA intermediates and their detrimental mechanisms of action in mitochondria and the ischaemic myocardium. In the present study, we found that the long-chain acyl-CoA and acylcarnitine content is increased in mitochondria isolated from an ischaemic area of the myocardium. In analysing the FA derivative content, we discovered that long-chain acylcarnitines, but not acyl-CoAs, accumulate at concentrations that are harmful to mitochondria. Acylcarnitine accumulation in the mitochondrial intermembrane space is a result of increased carnitine palmitoyltransferase 1 (CPT1) and decreased carnitine palmitoyltransferase 2 (CPT2) activity in ischaemic myocardium and it leads to inhibition of oxidative phosphorylation, which in turn induces mitochondrial membrane hyperpolarization and stimulates the production of reactive oxygen species (ROS) in cardiac mitochondria. Thanks to protection mediated by acyl-CoA-binding protein (ACBP), the heart is much better guarded against the damaging effects of acyl-CoAs than against acylcarnitines. Supplementation of perfusion buffer with palmitoylcarnitine (PC) before occlusion resulted in a 2-fold increase in the acylcarnitine content of the heart and increased the infarct size (IS) by 33%. A pharmacologically induced decrease in the mitochondrial acylcarnitine content reduced the IS by 44%. Long-chain acylcarnitines are harmful FA intermediates, accumulating in ischaemic heart mitochondria and inducing inhibition of oxidative phosphorylation. Therefore, decreasing the acylcarnitine content via cardioprotective drugs may represent a novel treatment strategy.
Asunto(s)
Carnitina/análogos & derivados , Mitocondrias Cardíacas/metabolismo , Daño por Reperfusión Miocárdica/metabolismo , Animales , Carnitina/metabolismo , Carnitina O-Palmitoiltransferasa/metabolismo , Masculino , Daño por Reperfusión Miocárdica/patología , Fosforilación Oxidativa , Ratas , Ratas WistarRESUMEN
CutC choline trimethylamine-lyase is an anaerobic bacterial glycyl radical enzyme (GRE) that cleaves choline to produce trimethylamine (TMA) and acetaldehyde. In humans, TMA is produced exclusively by the intestinal microbiota, and its metabolite, trimethylamine oxide, has been associated with a higher risk of cardiovascular diseases. Therefore, information about the three-dimensional structures of TMA-producing enzymes is important for microbiota-targeted drug discovery. We have cloned, expressed, and purified the CutC GRE and the activating enzyme CutD from Klebsiella pneumoniae, a representative of the human microbiota. We have determined the first crystal structures of both the choline-bound and choline-free forms of CutC and have discovered that binding of choline at the ligand-binding site triggers conformational changes in the enzyme structure, a feature that has not been observed for any other characterized GRE.
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Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Colina/metabolismo , Klebsiella pneumoniae/enzimología , Liasas/química , Liasas/metabolismo , Microbiota , Dominio Catalítico , Cromatografía en Gel , Quimotripsina/metabolismo , Electroforesis en Gel de Poliacrilamida , Humanos , Modelos Moleculares , Multimerización de Proteína , Estructura Terciaria de Proteína , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
Meldonium (mildronate; 3-(2,2,2-trimethylhydrazinium)propionate; THP; MET-88) is a clinically used cardioprotective drug, which mechanism of action is based on the regulation of energy metabolism pathways through l-carnitine lowering effect. l-Carnitine biosynthesis enzyme γ-butyrobetaine hydroxylase and carnitine/organic cation transporter type 2 (OCTN2) are the main known drug targets of meldonium, and through inhibition of these activities meldonium induces adaptive changes in the cellular energy homeostasis. Since l-carnitine is involved in the metabolism of fatty acids, the decline in its levels stimulates glucose metabolism and decreases concentrations of l-carnitine related metabolites, such as long-chain acylcarnitines and trimethylamine-N-oxide. Here, we briefly reviewed the pharmacological effects and mechanisms of meldonium in treatment of heart failure, myocardial infarction, arrhythmia, atherosclerosis and diabetes.
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Biomarcadores/metabolismo , Metilhidrazinas/farmacología , Metilhidrazinas/uso terapéutico , Miocardio/metabolismo , Animales , Cardiotónicos/farmacología , Cardiotónicos/uso terapéutico , Fármacos Cardiovasculares/farmacología , Fármacos Cardiovasculares/uso terapéutico , Enfermedades Cardiovasculares/tratamiento farmacológico , Enfermedades Cardiovasculares/metabolismo , HumanosRESUMEN
R-phenibut is a γ-aminobutyric acid (GABA)-B receptor and α2-δ subunit of the voltage-dependent calcium channel (VDCC) ligand. The aim of the present study was to test the effects of R-phenibut on the motor, sensory and tactile functions and histological outcomes in rats following transient middle cerebral artery occlusion (MCAO). In this study, MCAO was induced by filament insertion (f-MCAO) or endothelin-1 (ET1) microinjection (ET1-MCAO) in male Wistar or CD rats, respectively. R-phenibut was administrated at doses of 10 and 50mg/kg for 14 days in the f-MCAO or 7 days in the ET1-MCAO. The vibrissae-evoked forelimb-placing and limb-placing tests were used to assess sensorimotor, tactile and proprioceptive function. Quantitative reverse transcriptase-PCR was used to detect brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) gene expression in the damaged brain hemisphere. Both f-MCAO and ET1-MCAO resulted in statistically significant impairment of sensorimotor function and brain infarction. R-phenibut at a dose of 10mg/kg significantly improved histological outcome at day 7 in the ET1-MCAO. R-phenibut treatment at a dose of 50mg/kg significantly alleviated reduction of brain volume in damaged hemisphere in both f-MCAO and ET1-MCAO. In R-phenibut treated animals a trend of recovery of tactile and proprioceptive stimulation in the vibrissae-evoked forelimb-placing test was observed. After R-phenibut treatment at a dose of 50mg/kg statistically significant increase of BDNF and VEGF gene expression was found in damaged brain hemisphere. Taken together, obtained results provide evidence for the neuroprotective activity of R-phenibut in experimental models of stroke. These effects might be related to the modulatory effects of the drug on the GABA-B receptor and α2-δ subunit of VDCC.
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Isquemia Encefálica/tratamiento farmacológico , Proteínas del Ojo/farmacología , Fármacos Neuroprotectores/farmacología , Corteza Sensoriomotora/efectos de los fármacos , Animales , Isquemia Encefálica/metabolismo , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Canales de Calcio/metabolismo , Modelos Animales de Enfermedad , Miembro Anterior/efectos de los fármacos , Miembro Anterior/metabolismo , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Infarto de la Arteria Cerebral Media/metabolismo , Masculino , Ratas , Ratas Wistar , Receptores de GABA-B/metabolismo , Corteza Sensoriomotora/metabolismo , Accidente Cerebrovascular/tratamiento farmacológico , Accidente Cerebrovascular/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismoRESUMEN
The important pathological consequences of insulin resistance arise from the detrimental effects of accumulated long-chain fatty acids and their respective acylcarnitines. The aim of this study was to test whether exercise combined with decreasing the content of long-chain acylcarnitines represents an effective strategy to improve insulin sensitivity in diabetes. We used a novel compound, 4-[ethyl(dimethyl)ammonio]butanoate (methyl-GBB), treatment and exercise to decrease acylcarnitine contents in the plasma and muscles in the insulin resistance models of high fat diet (HFD) fed C57BL/6 mice and db/db mice. The methyl-GBB treatment induced a substantial decrease in all acylcarnitine concentrations in both fed and fasted states as well as when it was combined with exercise. In the HFD fed mice methyl-GBB treatment improved both glucose and insulin tolerance. Methyl-GBB administration, exercise and the combination of both improved insulin sensitivity and reduced blood glucose levels in db/db mice. Methyl-GBB administration and the combination of the drug and exercise activated the PPARα/PGC1α signaling pathway and stimulated the corresponding target gene expression. Insulin insensitivity in db/db mice was not induced by significantly increased fatty acid metabolism, while increased insulin sensitivity by both treatments was not related to decreased fatty acid metabolism in muscles. The pharmacologically reduced long-chain acylcarnitine content represents an effective strategy to improve insulin sensitivity. The methyl-GBB treatment and lifestyle changes via increased physical activity for one hour a day have additive insulin sensitizing effects in db/db mice.
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Carnitina/análogos & derivados , Resistencia a la Insulina/fisiología , Insulina/metabolismo , Condicionamiento Físico Animal/fisiología , Animales , Glucemia/efectos de los fármacos , Carnitina/sangre , Carnitina/metabolismo , Diabetes Mellitus/sangre , Diabetes Mellitus/tratamiento farmacológico , Diabetes Mellitus/metabolismo , Diabetes Mellitus Experimental/sangre , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Experimental/metabolismo , Dieta Alta en Grasa/efectos adversos , Modelos Animales de Enfermedad , Ácidos Grasos/metabolismo , Expresión Génica/efectos de los fármacos , Glucosa/metabolismo , Metabolismo de los Lípidos/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Músculos/efectos de los fármacos , Músculos/metabolismo , PPAR alfa/metabolismo , Compuestos de Amonio Cuaternario/farmacología , Transducción de Señal/efectos de los fármacos , Ácido gamma-Aminobutírico/análogos & derivados , Ácido gamma-Aminobutírico/farmacologíaRESUMEN
An ultra-high-performance liquid chromatography-mass spectrometry (UPLC/MS/MS) method was developed and validated for the quantification of trimethylamine-N-oxide (TMAO) simultaneously with TMAO-related molecules L-carnitine and γ-butyrobetaine (GBB) in human blood plasma. The separation of analytes was achieved using a Hydrophilic interaction liquid chromatography (HILIC)-type column with ammonium acetate-acetonitrile as the mobile phase. TMAO determination was validated according to valid US Food and Drug Administration guidelines. The developed method was successfully applied to plasma samples from healthy volunteers.
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Betaína/análogos & derivados , Carnitina/sangre , Cromatografía Liquida/métodos , Metilaminas/sangre , Espectrometría de Masas en Tándem/métodos , Betaína/sangre , Humanos , Límite de Detección , Estándares de Referencia , Reproducibilidad de los ResultadosRESUMEN
In the heart, a nutritional state (fed or fasted) is characterized by a unique energy metabolism pattern determined by the availability of substrates. Increased availability of acylcarnitines has been associated with decreased glucose utilization; however, the effects of long-chain acylcarnitines on glucose metabolism have not been previously studied. We tested how changes in long-chain acylcarnitine content regulate the metabolism of glucose and long-chain fatty acids in cardiac mitochondria in fed and fasted states. We examined the concentrations of metabolic intermediates in plasma and cardiac tissues under fed and fasted states. The effects of substrate availability and their competition for energy production at the mitochondrial level were studied in isolated rat cardiac mitochondria. The availability of long-chain acylcarnitines in plasma reflected their content in cardiac tissue in the fed and fasted states, and acylcarnitine content in the heart was fivefold higher in fasted state compared to the fed state. In substrate competition experiments, pyruvate and fatty acid metabolites effectively competed for the energy production pathway; however, only the physiological content of acylcarnitine significantly reduced pyruvate and lactate oxidation in mitochondria. The increased availability of long-chain acylcarnitine significantly reduced glucose utilization in isolated rat heart model and in vivo. Our results demonstrate that changes in long-chain acylcarnitine contents could orchestrate the interplay between the metabolism of pyruvate-lactate and long-chain fatty acids, and thus determine the pattern of energy metabolism in cardiac mitochondria.
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Carnitina/análogos & derivados , Metabolismo Energético , Glucosa/metabolismo , Mitocondrias Cardíacas/fisiología , Palmitoilcarnitina/administración & dosificación , Animales , Carnitina/metabolismo , Ayuno , Ácidos Grasos/metabolismo , Masculino , Ratones , Ratones Endogámicos ICR , Modelos Animales , Ratas , Ratas WistarRESUMEN
l-Carnitine is a cofactor in the energy metabolism pathways where it drives the uptake and oxidation of long chain fatty acids (LCFA) by mitochondria. LCFA lipotoxicity causes mitochondrial damage and results in an insufficient energy supply and a decrease in l-carnitine content limits LCFA flux and protects mitochondria. Here, we tested whether the inhibition of GBB dioxygenase (BBOX) or organic cation transporter 2 (OCTN2) is the most effective strategy to decrease l-carnitine content. The activity of 51 compounds was tested and we identified selective inhibitors of OCTN2. In contrast to selective inhibitors of BBOX, OCTN2 inhibitors induced a 10-fold decrease in l-carnitine content in the heart tissues and a significant 35% reduction of myocardial infarct size. In addition, OCTN2 inhibition correlated with the inhibitor content in the heart tissues, and OCTN2 could potentially be an efficient target to increase drug transport into tissues and to reduce drug elimination by urine. In conclusion, the results of this study confirm that selective inhibition of OCTN2, compared to selective inhibition of BBOX, is a far more effective approach to decrease l-carnitine content and to induce cardioprotective effects. OCTN2 could potentially be an efficient tool to increase drug transport in tissues and to reduce drug elimination via urine.
Asunto(s)
Cardiotónicos/uso terapéutico , Carnitina/metabolismo , Infarto del Miocardio/tratamiento farmacológico , Proteínas de Transporte de Catión Orgánico/antagonistas & inhibidores , gamma-Butirobetaína Dioxigenasa/antagonistas & inhibidores , Animales , Cardiotónicos/farmacología , Carnitina/sangre , Carnitina/orina , Masculino , Infarto del Miocardio/metabolismo , Miocardio/metabolismo , Ratas Wistar , Miembro 5 de la Familia 22 de Transportadores de SolutosRESUMEN
BACKGROUND AND OBJECTIVE: A nationwide survey of schoolchildren was conducted to detect regional differences in urinary iodine excretion in Latvia and to compare the results with data from the newborn thyroid-stimulating hormone (TSH) screening database as well with the results of a similar study performed in Latvia 10 years ago. MATERIALS AND METHODS: We conducted a cross-sectional school-based cluster survey of 915 children aged 9-12 years in 46 randomly selected schools in all regions of Latvia. Urine samples, questionnaires on the consumption of iodized salt and information on socioeconomic status were collected. TSH levels in newborns were also measured. RESULTS: The median creatinine-standardized urinary iodine concentration (UIC) in our study was 107.3µg/g Cr. UIC measurements indicative of mild iodine deficiency were present in 31.6%, moderate deficiency in 11.9% and severe deficiency in 2.8% of the participants. The prevalence of iodine deficiency was the highest in the southeastern region of Latgale and the northeastern region of Vidzeme. The prevalence of TSH values >5mIU/L followed a similar pattern. The self-reported prevalence of regular iodized salt consumption was 10.2%. Children from urban schools had a significantly lower UIC than children from rural schools. CONCLUSIONS: Our findings suggest that although the overall median UIC in Latvian schoolchildren falls within the lower normal range, almost 50% of the schoolchildren are iodine deficient, especially in urban schools and in the eastern part of Latvia. The absence of a mandatory salt iodization program puts a significant number of children and pregnant women at risk.
Asunto(s)
Yodo/deficiencia , Yodo/orina , Cloruro de Sodio Dietético/orina , Niño , Creatinina/orina , Estudios Transversales , Femenino , Humanos , Recién Nacido , Yodo/administración & dosificación , Letonia/epidemiología , Masculino , Prevalencia , Autoinforme , Cloruro de Sodio Dietético/administración & dosificación , Tirotropina/sangreRESUMEN
Birch outer bark extract (BBE), containing pentacyclic triterpenes such as betulin, lupeol, and betulinic acid, is a widely recognized natural product renowned for its diverse pharmacological effects. However, its limited water solubility restricts its bioavailability. Therefore, the main objective is to enhance the bioavailability of BBE for pharmaceutical use. In this study, we aimed to develop a dispersion system utilizing a unique oleogel-producing method through the recrystallization of BBE from an ethanol solution in the oil phase. We generated an oleogel that demonstrates a notable 42-80-fold improvement in betulin and lupeol peroral bioavailability from BBE in Wistar rats, respectively. A physical paste-like BBE hydrogel developed with antisolvent precipitation showed a 16-56-fold increase in the bioavailability of betulin and lupeol from BBE in rat blood plasma, respectively. We also observed that the repeated administration of the BBE oleogel did not exhibit any toxicity at the tested dose (38.5 mg/kg betulin, 5.2 mg/kg lupeol, 1.5 mg/kg betulinic acid daily for 7 days). Betulin and betulinic acid were not detected in rat heart, liver, kidney, or brain tissues after the peroral administration of the oleogel daily for 7 days. Lupeol was found in rat heart, liver, and kidney tissues.
RESUMEN
Statins are one of the most important classes of drugs. In this analytical review, we elucidate the intricate molecular mechanisms and toxicological rationale regarding both the on- (targeting 3-hydroxy-3-methylglutaryl-coenzyme A reductase [HMGCR]) and off-target effects of statins. Statins interact with a number of membrane kinases, such as epidermal growth factor receptor (EGFR), erb-b2 receptor tyrosine kinase 2 (HER2) and MET proto-oncogene, receptor tyrosine kinase (MET), as well as cytosolic kinases, such as SRC proto-oncogene, non-receptor tyrosine kinase (Src) and show inhibitory activity at nanomolar concentrations. In addition, they interact with calcium ATPases and peroxisome proliferator-activated receptor α (PPARα/NR1C1) at higher concentrations. Statins interact with mitochondrial complexes III and IV, and their inhibition of coenzyme Q10 synthesis also impairs the functioning of complexes I and II. Statins act as inhibitors of kinases, calcium ATPases and mitochondrial complexes, while activating PPARα. These off-target effects likely contribute to the side effects observed in patients undergoing statin therapy, including musculoskeletal symptoms and hepatic effects. Interestingly, some off-target effects of statins could also be the cause of favourable outcomes, relating to repurposing statins in conditions such as inflammatory disorders and cancer.