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Rapamycin slows cystogenesis in murine models of polycystic kidney disease (PKD) but failed in clinical trials, potentially due to insufficient drug dosing. To improve drug efficiency without increasing dose, kidney-specific drug delivery may be used. Mesoscale nanoparticles (MNP) selectively target the proximal tubules in rodents. We explored whether MNPs can target cystic kidney tubules and whether rapamycin-encapsulated-MNPs (RapaMNPs) can slow cyst growth in Pkd1 knockout (KO) mice. MNP was intravenously administered in adult Pkd1KO mice. Serum and organs were harvested after 8, 24, 48 or 72 h to measure MNP localization, mTOR levels, and rapamycin concentration. Pkd1KO mice were then injected bi-weekly for 6 weeks with RapaMNP, rapamycin, or vehicle to determine drug efficacy on kidney cyst growth. Single MNP injections lead to kidney-preferential accumulation over other organs, specifically in tubules and cysts. Likewise, one RapaMNP injection resulted in higher drug delivery to the kidney compared to the liver, and displayed sustained mTOR inhibition. Bi-weekly injections with RapaMNP, rapamycin or vehicle for 6 weeks resulted in inconsistent mTOR inhibition and little change in cyst index, however. MNPs serve as an effective short-term, kidney-specific delivery system, but long-term RapaMNP failed to slow cyst progression in Pkd1KO mice.
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Modelos Animales de Enfermedad , Ratones Noqueados , Nanopartículas , Enfermedades Renales Poliquísticas , Sirolimus , Animales , Sirolimus/administración & dosificación , Sirolimus/farmacología , Ratones , Enfermedades Renales Poliquísticas/tratamiento farmacológico , Enfermedades Renales Poliquísticas/metabolismo , Enfermedades Renales Poliquísticas/genética , Enfermedades Renales Poliquísticas/patología , Nanopartículas/administración & dosificación , Serina-Treonina Quinasas TOR/metabolismo , Canales Catiónicos TRPP/genética , Canales Catiónicos TRPP/metabolismo , Riñón/metabolismo , Riñón/efectos de los fármacos , Riñón/patología , Sistemas de Liberación de Medicamentos , MasculinoRESUMEN
The extracellular cellular matrix (ECM) maintains tissue structure and regulates signaling functions by continuous degradation and remodeling. Inflammation or other disease conditions activate proteases including matrix metalloproteinases (MMPs) that degrade ECM proteins and in particular generate fragments of collagen and elastin, some of which are biologically active ECM peptides or matrikines. Stepwise degradation of collagen by MMP 8, 9 and prolyl endopeptidase release the matrikine proline-glycine-proline (PGP) and its product acetyl-PGP (AcPGP). These peptides are considered as potential biomarkers and therapeutic targets for many disease conditions such as chronic lung disease, heart disease, and cancer. However, there is no published, validated method for the measurement of PGP and AcPGP in plasma and therefore, we developed a sensitive, selective and reliable, isotope dilution LC-multiple reaction monitoring MS method for their determination in human plasma. The chromatographic separation of PGP and AcPGP was achieved in 3 min using Jupiter column with a gradient consisting of acidified acetonitrile and water at a flow rate of 0.5 ml/min. The limit of detection (LOD) for PGP and AcPGP was 0.01 ng/ml and the limit of quantification (LOQ) was 0.05 ng/ml and 0.1 ng/ml, respectively. Precision and accuracy values for all analytes were within 20 % except for the lowest QC of 0.01 ng/ml. The mean extraction recoveries of these analytes were > 90 % using a Phenomenex Phree cartridge and the matrix effect was < 15 % for all the QCs for PGP and AcPGP except the lowest QC. The stability of PGP and AcPGP was > 90 % in several tested conditions including autosampler use, storage at -80 °C, and after 6 times freeze-thaw cycles. Using this method, we successfully extracted and determined PGP levels in human plasma from healthy and COPD subjects. Therefore, this method is suitable for quantification of these peptides in the clinical setting.
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Glicina , Prolina , Humanos , Cromatografía Liquida , Espectrometría de Masas en Tándem , Péptidos , ColágenoRESUMEN
Investigations into the causative role that western dietary patterns have on obesity and disease pathogenesis have speculated that quality and quantity of dietary fats and/or carbohydrates have a predictive role in the development of these disorders. Standard reference diets such as the AIN-93 rodent diet have historically been used to promote animal health and reduce variation of results across experiments, rather than model modern human dietary habits or nutrition-related pathologies. In rodents high-fat diets (HFDs) became a classic tool to investigate diet-induced obesity (DIO). These murine diets often relied on a single fat source with the most DIO consistent HFDs containing levels of fat up to 45-60% (kcal), higher than the reported human intake of 33-35% (kcal). More recently, researchers are formulating experimental animal (pre-clinical) diets that reflect mean human macro- and micronutrient consumption levels described by the National Health and Nutrition Examination Survey (NHANES). These diets attempt to integrate relevant ingredient sources and levels of nutrients; however, they most often fail to include high-fructose corn syrup (HFCS) as a source of dietary carbohydrate. We have formulated a modified Standard American Diet (mSAD) that incorporates relevant levels and sources of nutrient classes, including dietary HFCS, to assess the basal physiologies associated with mSAD consumption. Mice proffered the mSAD for 15 weeks displayed a phenotype consistent with metabolic syndrome, exhibiting increased adiposity, fasting hyperglycemia with impaired glucose and insulin tolerance. Metabolic alterations were evidenced at the tissue level as crown-like structures (CLS) in adipose tissue and fatty acid deposition in the liver, and targeted 16S rRNA metagenomics revealed microbial compositional shifts between dietary groups. This study suggests diet quality significantly affects metabolic homeostasis, emphasizing the importance of developing relevant pre-clinical diets to investigate chronic diseases highly impacted by western dietary consumption patterns.
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INTRODUCTION: Acute kidney injury (AKI) is common in COVID-19 and associated with increased morbidity and mortality. We investigated alterations in the urine metabolome to test the hypothesis that impaired nicotinamide adenine dinucleotide (NAD+) biosynthesis and other deficiencies in energy metabolism in the kidney, previously characterized in ischemic, toxic, and inflammatory etiologies of AKI, will be present in COVID-19-associated AKI. METHODS: This is a case-control study among the following 2 independent populations of adults hospitalized with COVID-19: a critically ill population in Boston, Massachusetts, and a general population in Birmingham, Alabama. The cases had AKI stages 2 or 3 by Kidney Disease Improving Global Outcomes (KDIGO) criteria; the controls had no AKI. Metabolites were measured by liquid chromatography-mass spectrometry. RESULTS: A total of 14 cases and 14 controls were included from Boston and 8 cases and 10 controls from Birmingham. Increased urinary quinolinate-to-tryptophan ratio (Q/T), found with impaired NAD+ biosynthesis, was present in the cases at each location and pooled across locations (median [interquartile range]: 1.34 [0.59-2.96] in cases, 0.31 [0.13-1.63] in controls, P = 0.0013). Altered energy metabolism and purine metabolism contributed to a distinct urinary metabolomic signature that differentiated patients with and without AKI (supervised random forest class error: 2 of 28 in Boston, 0 of 18 in Birmingham). CONCLUSION: Urinary metabolites spanning multiple biochemical pathways differentiate AKI versus non-AKI in patients hospitalized with COVID-19 and suggest a conserved impairment in NAD+ biosynthesis, which may present a novel therapeutic target to mitigate COVID-19-associated AKI.
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The neurobiological mechanisms that mediate psychiatric comorbidities associated with metabolic disorders such as obesity, metabolic syndrome and diabetes remain obscure. High fructose corn syrup (HFCS) is widely used in beverages and is often included in food products with moderate or high fat content that have been linked to many serious health issues including diabetes and obesity. However, the impact of such foods on the brain has not been fully characterized. Here, we evaluated the effects of long-term consumption of a HFCS-Moderate Fat diet (HFCS-MFD) on behavior, neuronal signal transduction, gut microbiota, and serum metabolomic profile in mice to better understand how its consumption and resulting obesity and metabolic alterations relate to behavioral dysfunction. Mice fed HFCS-MFD for 16 weeks displayed enhanced anxiogenesis, increased behavioral despair, and impaired social interactions. Furthermore, the HFCS-MFD induced gut microbiota dysbiosis and lowered serum levels of serotonin and its tryptophan-based precursors. Importantly, the HFCS-MFD altered neuronal signaling in the ventral striatum including reduced inhibitory phosphorylation of glycogen synthase kinase 3ß (GSK3ß), increased expression of ΔFosB, increased Cdk5-dependent phosphorylation of DARPP-32, and reduced PKA-dependent phosphorylation of the GluR1 subunit of the AMPA receptor. These findings suggest that HFCS-MFD-induced changes in the gut microbiota and neuroactive metabolites may contribute to maladaptive alterations in ventral striatal function that underlie neurobehavioral impairment. While future studies are essential to further evaluate the interplay between these factors in obesity and metabolic syndrome-associated behavioral comorbidities, these data underscore the important role of peripheral-CNS interactions in diet-induced behavioral and brain function. This study also highlights the clinical need to address neurobehavioral comorbidities associated with obesity and metabolic syndrome.
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Breast cancer is a hormonally-driven cancer, and various dietary factors are associated with estrogen metabolism, including dietary fiber. Several studies report associations between dietary fiber and breast cancer; however, research on whether fiber influences circulating estrogens through the gut microbiota is rare. The objective of this cross-sectional study among 29 newly-diagnosed (stage 0-II), post-menopausal breast cancer patients is to examine associations between dietary fiber and the gut microbiota that are linked with ß-glucuronidase activity, and purportedly increase circulating estrogens. Spearman's and partial correlations controlling for body mass index and age were performed using dietary recall data, Illumina MiSeq generated microbiota relative abundance, and HPLC-mass spectrometry-derived estradiol and estrone levels.Major findings are: (1) total dietary fiber is inversely associated with Clostridium hathewayi (r= -0.419; p = 0.024); (2) soluble fiber is inversely associated with Clostridium (r=-0.11; p = 0.02); (3) insoluble fiber is positively associated with Bacteroides uniformis sp. (r = 0.382; p = 0.041); and (4) serum estradiol and estrone levels are not correlated with species/genera or dietary fiber, though there is a trend toward an inverse association between soluble fiber and estradiol levels (r= -0.30; p = 0.12). More studies are needed to understand the complex interaction between dietary fiber, intestinal microbiota, and hormonal levels in older females.
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Neoplasias de la Mama , Microbiota , Anciano , Bacteroides , Clostridiaceae , Estudios Transversales , Fibras de la Dieta , Estrógenos , Femenino , Humanos , PosmenopausiaRESUMEN
Breast cancer is the second leading cause of cancer-related mortality in women. Various nutritional compounds possess anti-carcinogenic properties which may be mediated through their effects on the gut microbiota and its production of short-chain fatty acids (SCFAs) for the prevention of breast cancer. We evaluated the impact of broccoli sprouts (BSp), green tea polyphenols (GTPs) and their combination on the gut microbiota and SCFAs metabolism from the microbiota in Her2/neu transgenic mice that spontaneously develop estrogen receptor-negative [ER(-)] mammary tumors. The mice were grouped based on the dietary treatment: control, BSp, GTPs or their combination from beginning in early life (BE) or life-long from conception (LC). We found that the combination group showed the strongest inhibiting effect on tumor growth volume and a significant increase in tumor latency. BSp treatment was integrally more efficacious than the GTPs group when compared to the control group. There was similar clustering of microbiota of BSp-fed mice with combination-fed mice, and GTPs-fed mice with control-fed mice at pre-tumor in the BE group and at pre-tumor and post-tumor in the LC group. The mice on all dietary treatment groups incurred a significant increase of Adlercreutzia, Lactobacillus genus and Lachnospiraceae, S24-7 family in the both BE and LC groups. We found no change in SCFAs levels in the plasma of BSp-fed, GTPs-fed and combination-fed mice of the BE group. Marked changes were observed in the mice of the LC group consisting of significant increases in propionate and isobutyrate in GTPs-fed and combination-fed mice. These studies indicate that nutrients such as BSp and GTPs differentially affect the gut microbial composition in both the BE and LC groups and the key metabolites (SCFAs) levels in the LC group. The findings also suggest that temporal factors related to different time windows of consumption during the life-span can have a promising influence on the gut microbial composition, SCFAs profiles and ER(-) breast cancer prevention.
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Dieta/métodos , Ácidos Grasos Volátiles/sangre , Microbioma Gastrointestinal/efectos de los fármacos , Neoplasias Mamarias Experimentales/prevención & control , Polifenoles/farmacología , Plantones/química , Actinobacteria/efectos de los fármacos , Actinobacteria/aislamiento & purificación , Actinobacteria/fisiología , Animales , Brassica/química , Clostridiales/efectos de los fármacos , Clostridiales/aislamiento & purificación , Clostridiales/fisiología , Femenino , Microbioma Gastrointestinal/fisiología , Expresión Génica , Lactobacillus/efectos de los fármacos , Lactobacillus/aislamiento & purificación , Lactobacillus/fisiología , Glándulas Mamarias Animales/efectos de los fármacos , Glándulas Mamarias Animales/metabolismo , Glándulas Mamarias Animales/patología , Neoplasias Mamarias Experimentales/sangre , Neoplasias Mamarias Experimentales/genética , Neoplasias Mamarias Experimentales/patología , Ratones , Ratones Noqueados , Polifenoles/química , Receptor ErbB-2/deficiencia , Receptor ErbB-2/genética , Receptores de Estrógenos/deficiencia , Receptores de Estrógenos/genética , Té/químicaRESUMEN
Macrophages are important in mounting an innate immune response to injury as well as in repair of injury. Gene expression of Rho proteins is known to be increased in fibrotic models; however, the role of these proteins in idiopathic pulmonary fibrosis (IPF) is not known. Here, we show that BAL cells from patients with IPF have a profibrotic phenotype secondary to increased activation of the small GTPase Rac1. Rac1 activation requires a posttranslational modification, geranylgeranylation, of the C-terminal cysteine residue. We found that by supplying more substrate for geranylgeranylation, Rac1 activation was substantially increased, resulting in profibrotic polarization by increasing flux through the mevalonate pathway. The increased flux was secondary to greater levels of acetyl-CoA from metabolic reprogramming to ß oxidation. The polarization mediated fibrotic repair in the absence of injury by enhancing macrophage/fibroblast signaling. These observations suggest that targeting the mevalonate pathway may abrogate the role of macrophages in dysregulated fibrotic repair.
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Fibrosis Pulmonar Idiopática/metabolismo , Macrófagos/metabolismo , Ácido Mevalónico/metabolismo , Acetilcoenzima A/genética , Acetilcoenzima A/metabolismo , Adolescente , Adulto , Anciano , Animales , Femenino , Humanos , Fibrosis Pulmonar Idiopática/genética , Fibrosis Pulmonar Idiopática/patología , Macrófagos/patología , Masculino , Ratones , Ratones Noqueados , Persona de Mediana Edad , Neuropéptidos/genética , Neuropéptidos/metabolismo , Oxidación-Reducción , Proteína de Unión al GTP rac1/genética , Proteína de Unión al GTP rac1/metabolismoRESUMEN
Cigarette smoking is associated with chronic obstructive pulmonary disease and chronic bronchitis. Acquired ion transport abnormalities, including cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction, caused by cigarette smoking have been proposed as potential mechanisms for mucus obstruction in chronic bronchitis. Although e-cigarette use is popular and perceived to be safe, whether it harms the airways via mechanisms altering ion transport remains unclear. In the present study, we sought to determine if e-cigarette vapor, like cigarette smoke, has the potential to induce acquired CFTR dysfunction, and to what degree. Electrophysiological methods demonstrated reduced chloride transport caused by vaporized e-cigarette liquid or vegetable glycerin at various exposures (30 min, 57.2% and 14.4% respectively, vs. control; P < 0.0001), but not by unvaporized liquid (60 min, 17.6% vs. untreated), indicating that thermal degradation of these products is required to induce the observed defects. We also observed reduced ATP-dependent responses (-10.8 ± 3.0 vs. -18.8 ± 5.1 µA/cm2 control) and epithelial sodium channel activity (95.8% reduction) in primary human bronchial epithelial cells after 5 minutes, suggesting that exposures dramatically inhibit epithelial ion transport beyond CFTR, even without diminished transepithelial resistance or cytotoxicity. Vaporizing e-cigarette liquid produced reactive aldehydes, including acrolein (shown to induce acquired CFTR dysfunction), as quantified by mass spectrometry, demonstrating that respiratory toxicants in cigarette smoke can also be found in e-cigarette vapor (30 min air, 224.5 ± 15.99; unvaporized liquid, 284.8 ± 35.03; vapor, 54,468 ± 3,908 ng/ml; P < 0.0001). E-cigarettes can induce ion channel dysfunction in airway epithelial cells, partly through acrolein production. These findings indicate a heretofore unknown toxicity of e-cigarette use known to be associated with chronic bronchitis onset and progression, as well as with chronic obstructive pulmonary disease severity.
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Sistemas Electrónicos de Liberación de Nicotina , Células Epiteliales/efectos de los fármacos , Glicerol/efectos adversos , Transporte Iónico , Humo/efectos adversos , Fumar/efectos adversos , Acroleína/química , Adenosina Trifosfato/metabolismo , Bronquios/metabolismo , Bronquitis Crónica/fisiopatología , Supervivencia Celular , Fumar Cigarrillos , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Progresión de la Enfermedad , Electrofisiología , Células Epiteliales/metabolismo , Glicerol/metabolismo , Humanos , Espectrometría de Masas , Moco/metabolismo , Nebulizadores y Vaporizadores , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Sistema Respiratorio/efectos de los fármacos , Factores de TiempoRESUMEN
Deficiency in polycystin 1 triggers specific changes in energy metabolism. To determine whether defects in other human cystoproteins have similar effects, we studied extracellular acidification and glucose metabolism in human embryonic kidney (HEK-293) cell lines with polycystic kidney and hepatic disease 1 ( PKHD1) and polycystic kidney disease (PKD) 2 ( PKD2) truncating defects along multiple sites of truncating mutations found in patients with autosomal recessive and dominant PKDs. While neither the PKHD1 or PKD2 gene mutations nor their position enhanced cell proliferation rate in our cell line models, truncating mutations in these genes progressively increased overall extracellular acidification over time ( P < 0.001 for PKHD1 and PKD2 mutations). PKHD1 mutations increased nonglycolytic acidification rate (1.19 vs. 1.03, P = 0.002), consistent with an increase in tricarboxylic acid cycle activity or breakdown of intracellular glycogen. In addition, they increased basal and ATP-linked oxygen consumption rates [7.59 vs. 5.42 ( P = 0.015) and 4.55 vs. 2.98 ( P = 0.004)]. The PKHD1 and PKD2 mutations also altered mitochondrial morphology, resembling the effects of polycystin 1 deficiency. Together, these data suggest that defects in major PKD genes trigger changes in mitochondrial energy metabolism. After validation in in vivo models, these initial observations would indicate potential benefits of targeting energy metabolism in the treatment of PKDs.
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Metabolismo Energético/genética , Glucosa/metabolismo , Proteínas Quinasas/genética , Receptores de Superficie Celular/genética , Proliferación Celular/genética , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Edición Génica , Células HEK293 , Humanos , Mutación , Proteína Quinasa D2 , Proteínas Quinasas/metabolismo , Receptores de Superficie Celular/metabolismoRESUMEN
Glucagon, an essential regulator of glucose and lipid metabolism, also promotes weight loss, in part through potentiation of fibroblast growth factor 21 (FGF21) secretion. However, FGF21 is only a partial mediator of metabolic actions ensuing from glucagon receptor (GCGR) activation, prompting us to search for additional pathways. Intriguingly, chronic GCGR agonism increases plasma bile acid levels. We hypothesized that GCGR agonism regulates energy metabolism, at least in part, through farnesoid X receptor (FXR). To test this hypothesis, we studied whole-body and liver-specific FXR-knockout (Fxr∆liver) mice. Chronic GCGR agonist (IUB288) administration in diet-induced obese (DIO) Gcgr, Fgf21, and Fxr whole-body or liver-specific knockout (∆liver) mice failed to reduce body weight when compared with wild-type (WT) mice. IUB288 increased energy expenditure and respiration in DIO WT mice, but not Fxr∆liver mice. GCGR agonism increased [14C]palmitate oxidation in hepatocytes isolated from WT mice in a dose-dependent manner, an effect blunted in hepatocytes from Fxr∆liver mice. Our data clearly demonstrate that control of whole-body energy expenditure by GCGR agonism requires intact FXR signaling in the liver. This heretofore-unappreciated aspect of glucagon biology has implications for the use of GCGR agonism in the therapy of metabolic disorders.
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Fármacos Antiobesidad/uso terapéutico , Metabolismo Energético/efectos de los fármacos , Factores de Crecimiento de Fibroblastos/metabolismo , Hígado/efectos de los fármacos , Obesidad/tratamiento farmacológico , Receptores Citoplasmáticos y Nucleares/metabolismo , Receptores de Glucagón/agonistas , Adiposidad/efectos de los fármacos , Animales , Calorimetría Indirecta , Células Cultivadas , Dieta Alta en Grasa/efectos adversos , Factores de Crecimiento de Fibroblastos/genética , Regulación de la Expresión Génica/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Mitocondrias Hepáticas/efectos de los fármacos , Mitocondrias Hepáticas/enzimología , Mitocondrias Hepáticas/metabolismo , Obesidad/etiología , Obesidad/metabolismo , Obesidad/patología , Especificidad de Órganos , Fosforilación Oxidativa/efectos de los fármacos , Péptidos/uso terapéutico , Receptores Citoplasmáticos y Nucleares/genética , Receptores de Glucagón/genética , Receptores de Glucagón/metabolismo , Transducción de Señal/efectos de los fármacos , Aumento de Peso/efectos de los fármacosRESUMEN
Mitochondrial quality is under surveillance by autophagy, the cell recycling process which degrades and removes damaged mitochondria. Inadequate autophagy results in deterioration in mitochondrial quality, bioenergetic dysfunction, and metabolic stress. Here we describe in an integrated work-flow to assess parameters of mitochondrial morphology, function, mtDNA and protein damage, metabolism and autophagy regulation to provide the framework for a practical assessment of mitochondrial quality. This protocol has been tested with cell cultures, is highly reproducible, and is adaptable to studies when cell numbers are limited, and thus will be of interest to researchers studying diverse physiological and pathological phenomena in which decreased mitochondrial quality is a contributory factor.
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ADN Mitocondrial/metabolismo , Metabolismo Energético/genética , Mitocondrias/metabolismo , Mitofagia/genética , Animales , Autofagia/genética , Encéfalo/metabolismo , Técnicas de Cultivo de Célula , Humanos , Ratones , Mitocondrias/genética , Neuronas/metabolismo , Control de Calidad , RatasRESUMEN
Chlamydiatrachomatis (Ct) infection causes significant morbidity. In vitro studies demonstrate that Ct growth inhibition occurs by interferon-gamma (IFN-γ)-mediated depletion of intracellular tryptophan, and some Ct strains utilize extracellular indole to restore tryptophan levels. Whether tryptophan levels are associated with Ct infection clearance in humans remains unknown. We evaluated tryptophan, indole, and IFN-γ levels in cervicovaginal lavages from women with either naturally cleared or persisting Ct infection. Women who cleared infection had significantly lower tryptophan levels and trended toward lower IFN-γ levels compared to women with persisting infection. Due to its volatility, indole was not measurable in either group.
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Infecciones por Chlamydia/tratamiento farmacológico , Chlamydia trachomatis/inmunología , Interferón gamma/análisis , Triptófano/análisis , Adolescente , Adulto , Azitromicina/administración & dosificación , Femenino , Humanos , Persona de Mediana Edad , Ducha Vaginal , Adulto JovenRESUMEN
Autophagy is an important cell recycling program responsible for the clearance of damaged or long-lived proteins and organelles. Pharmacological modulators of this pathway have been extensively utilized in a wide range of basic research and pre-clinical studies. Bafilomycin A1 and chloroquine are commonly used compounds that inhibit autophagy by targeting the lysosomes but through distinct mechanisms. Since it is now clear that mitochondrial quality control, particularly in neurons, is dependent on autophagy, it is important to determine whether these compounds modify cellular bioenergetics. To address this, we cultured primary rat cortical neurons from E18 embryos and used the Seahorse XF96 analyzer and a targeted metabolomics approach to measure the effects of bafilomycin A1 and chloroquine on bioenergetics and metabolism. We found that both bafilomycin and chloroquine could significantly increase the autophagosome marker LC3-II and inhibit key parameters of mitochondrial function, and increase mtDNA damage. Furthermore, we observed significant alterations in TCA cycle intermediates, particularly those downstream of citrate synthase and those linked to glutaminolysis. Taken together, these data demonstrate a significant impact of bafilomycin and chloroquine on cellular bioenergetics and metabolism consistent with decreased mitochondrial quality associated with inhibition of autophagy.
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Autofagia/genética , Proteínas Asociadas a Microtúbulos/genética , Mitocondrias/metabolismo , Neuronas/metabolismo , Animales , Cloroquina/farmacología , Daño del ADN/efectos de los fármacos , ADN Mitocondrial/efectos de los fármacos , Metabolismo Energético/genética , Lisosomas/efectos de los fármacos , Lisosomas/genética , Macrólidos/farmacología , Metabolómica/métodos , Proteínas Asociadas a Microtúbulos/metabolismo , Neuronas/efectos de los fármacos , RatasRESUMEN
BACKGROUND: Immunoglobulin A (IgA) plays a key role in coating luminal antigens and preventing translocation of harmful bacteria. The aryl hydrocarbon receptor (AhR) is a basic helix-loop-helix transcription factor that when stimulated activates factors important for barrier function and intestinal homeostasis. We hypothesize that AhR signaling is critical for establishment of intestinal homeostasis in neonates. MATERIAL AND METHODS: Mice: C57BL/6 (B6) AhR+/+ wild type (WT), B6.AhR-/- Aryl-hydrocarbon receptor knockout (KO), and B6.AhR+/+ raised on an AhR ligand-free diet (AhR LF). Enzyme-linked immunosorbent assay was used to measure fecal and serum IgA levels. Bacterial translocation was measured by culturing the mesenteric lymph nodes. RESULTS: Two week old KO mice had significantly less fecal IgA compared with WT (and AhR LF, P value = 0.0393. The amount of IgA from the gastric contents of 2-wk-old mice was not significantly different. At age 8 wk, AhR LF mice had significantly less fecal IgA than WT and KO P value = 0.0077. At 2 wk, KO mice had significantly higher levels of bacterial translocation and at 8 wk AhR LF had significantly higher levels of bacterial translocation compared with WT. CONCLUSIONS: In neonatal mice, the lack of AhR signaling is associated with loss of intestinal homeostasis, evidenced by decreased levels of IgA and increased bacterial translocation. In adult mice, exogenous AhR ligand and not receptor signaling is necessary for maintenance of intestinal integrity.
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Intestinos/inmunología , Receptores de Hidrocarburo de Aril/metabolismo , Animales , Animales Recién Nacidos , Linfocitos B/fisiología , Traslocación Bacteriana , Homeostasis , Inmunoglobulina A/sangre , Linfocitos/fisiología , Ratones Endogámicos C57BL , Ratones NoqueadosRESUMEN
Necrotizing enterocolitis (NEC) is a major cause of morbidity and mortality in premature infants. The pathophysiology is likely secondary to innate immune responses to intestinal microbiota by the premature infant's intestinal tract, leading to inflammation and injury. This review provides an updated summary of the components of the innate immune system involved in NEC pathogenesis. In addition, we evaluate the animal models that have been used to study NEC with regard to the involvement of innate immune factors and histopathological changes as compared to those seen in infants with NEC. Finally, we discuss new approaches to studying NEC, including mathematical models of intestinal injury and the use of humanized mice.