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1.
Sci Rep ; 10(1): 10562, 2020 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-32601308

RESUMO

Levels of iron and iron-related proteins including ferritin are higher in the lung tissue and lavage fluid of individuals with chronic obstructive pulmonary disease (COPD), when compared to healthy controls. Whether more iron in the extracellular milieu of the lung associates with distinct clinical phenotypes of COPD, including increased exacerbation susceptibility, is unknown. We measured iron and ferritin levels in the bronchoalveolar lavage fluid (BALF) of participants enrolled in the SubPopulations and InteRmediate Outcome Measures In COPD (SPIROMICS) bronchoscopy sub-study (n = 195). BALF Iron parameters were compared to systemic markers of iron availability and tested for association with FEV1 % predicted and exacerbation frequency. Exacerbations were modelled using a zero-inflated negative binomial model using age, sex, smoking, and FEV1 % predicted as clinical covariates. BALF iron and ferritin were higher in participants with COPD and in smokers without COPD when compared to non-smoker control participants but did not correlate with systemic iron markers. BALF ferritin and iron were elevated in participants who had COPD exacerbations, with a 2-fold increase in BALF ferritin and iron conveying a 24% and 2-fold increase in exacerbation risk, respectively. Similar associations were not observed with plasma ferritin. Increased airway iron levels may be representative of a distinct pathobiological phenomenon that results in more frequent COPD exacerbation events, contributing to disease progression in these individuals.

2.
Cells ; 9(6)2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32492897

RESUMO

While the growth hormone/insulin-like growth factor-1 (GH/IGF-1) pathway plays essential roles in growth and development, diminished signaling via this pathway in model organisms extends lifespan and health-span. In humans, circulating IGF-1 and IGF-binding proteins 3 and 1 (IGFBP-3 and 1), surrogate measures of GH/IGF-1 system activity, have not been consistently associated with morbidity and mortality. In a prospective cohort of independently-living older adults (n = 840, mean age 76.1 ± 6.8 years, 54.5% female, median follow-up 6.9 years), we evaluated the age- and sex-adjusted hazards for all-cause mortality and incident age-related diseases, including cardiovascular disease, diabetes, cancer, and multiple-domain cognitive impairment (MDCI), as predicted by baseline total serum IGF-1, IGF-1/IGFBP-3 molar ratio, IGFBP-3, and IGFBP-1 levels. All-cause mortality was positively associated with IGF-1/IGFBP-3 molar ratio (HR 1.28, 95% CI 1.05-1.57) and negatively with IGFBP-3 (HR 0.82, 95% CI 0.680-0.998). High serum IGF-1 predicted greater risk for MDCI (HR 1.56, 95% CI 1.08-2.26) and composite incident morbidity (HR 1.242, 95% CI 1.004-1.538), whereas high IGFBP-1 predicted lower risk for diabetes (HR 0.50, 95% CI 0.29-0.88). In conclusion, higher IGF-1 levels and bioavailability predicted mortality and morbidity risk, supporting the hypothesis that diminished GH/IGF-1 signaling may contribute to human longevity and health-span.

5.
J Proteome Res ; 19(5): 2105-2112, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32183509

RESUMO

Protein homeostasis, proteostasis, is essential for healthy cell functioning and is dysregulated in many diseases. Metabolic labeling with heavy water followed by liquid chromatography coupled online to mass spectrometry (LC-MS) is a powerful high-throughput technique to study proteome dynamics in vivo. Longer labeling duration and dense timepoint sampling (TPS) of tissues provide accurate proteome dynamics estimations. However, the experiments are expensive, and they require animal housing and care, as well as labeling with stable isotopes. Often, the animals are sacrificed at selected timepoints to collect tissues. Therefore, it is necessary to optimize TPS for a given number of sampling points and labeling duration and target a specific tissue of study. Currently, such techniques are missing in proteomics. Here, we report on a formula-based stochastic simulation strategy for TPS for in vivo studies with heavy water metabolic labeling and LC-MS. We model the rate constant (lognormal), measurement error (Laplace), peptide length (gamma), relative abundance of the monoisotopic peak (beta regression), and the number of exchangeable hydrogens (gamma regression). The parameters of the distributions are determined using the corresponding empirical probability density functions from a large-scale dataset of murine heart proteome. The models are used in the simulations of the rate constant to minimize the root-mean-square error (rmse). The rmse for different TPSs shows structured patterns. They are analyzed to elucidate common features in the patterns.

6.
JCI Insight ; 5(3)2020 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-31895696

RESUMO

BACKGROUNDMitochondrial dysfunction, a proposed mechanism of chronic obstructive pulmonary disease (COPD) pathogenesis, is associated with the leakage of mitochondrial DNA (mtDNA), which may be detected extracellularly in various bodily fluids. Despite evidence for the increased prevalence of chronic kidney disease in COPD subjects and for mitochondrial dysfunction in the kidneys of murine COPD models, whether urine mtDNA (u-mtDNA) associates with measures of disease severity in COPD is unknown.METHODSCell-free u-mtDNA, defined as copy number of mitochondrially encoded NADH dehydrogenase-1 (MTND1) gene, was measured by quantitative PCR and normalized to urine creatinine in cell-free urine samples from participants in the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS) cohort. Urine albumin/creatinine ratios (UACR) were measured in the same samples. Associations between u-mtDNA, UACR, and clinical disease parameters - including FEV1 % predicted, clinical measures of exercise tolerance, respiratory symptom burden, and chest CT measures of lung structure - were examined.RESULTSU-mtDNA and UACR levels were measured in never smokers (n = 64), smokers without airflow obstruction (n = 109), participants with mild/moderate COPD (n = 142), and participants with severe COPD (n = 168). U-mtDNA was associated with increased respiratory symptom burden, especially among smokers without COPD. Significant sex differences in u-mtDNA levels were observed, with females having higher u-mtDNA levels across all study subgroups. U-mtDNA associated with worse spirometry and CT emphysema in males only and with worse respiratory symptoms in females only. Similar associations were not found with UACR.CONCLUSIONU-mtDNA levels may help to identify distinct clinical phenotypes and underlying pathobiological differences in males versus females with COPD.TRIAL REGISTRATIONThis study has been registered at ClinicalTrials.gov ( NCT01969344).FUNDINGUS NIH, National Heart, Lung and Blood Institute, supplemented by contributions made through the Foundation for the NIH and the COPD Foundation from AstraZeneca/MedImmune, Bayer, Bellerophon Therapeutics, Boehringer-Ingelheim Pharmaceuticals Inc., Chiesi Farmaceutici S.p.A., Forest Research Institute Inc., GlaxoSmithKline, Grifols Therapeutics Inc., Ikaria Inc., Novartis Pharmaceuticals Corporation, Nycomed GmbH, ProterixBio, Regeneron Pharmaceuticals Inc., Sanofi, Sunovion, Takeda Pharmaceutical Company, and Theravance Biopharma and Mylan.

8.
ACS Appl Mater Interfaces ; 11(45): 42280-42287, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31682096

RESUMO

Glass and glass-ceramic samples of metastable lithium thiophosphates with compositions of 70Li2S-30P2S5 and Li7P3S11 were controllably prepared by using a rapid assisted-microwave procedure in under 30 min. The rapid preparation times and weak coupling of the evacuated silica ampules with microwave radiation ensure minimal reactivity of the reactants and the container. The microwave-prepared samples display comparable conductivity values with more conventionally prepared (melt quenched) glass and glass-ceramic samples, on the order of 0.1 and 1 mS cm-1 at room temperature, respectively. Rietveld analysis of synchrotron X-ray diffraction data acquired with an internal standard quantitatively yields phase amounts of the glassy and amorphous components, establishing the tunable nature of the microwave preparation. X-ray photoelectron spectroscopy and Raman spectroscopy confirm the composition and the appropriate ratios of isolated and corner-sharing tetrahedra in these semicrystalline systems. Solid-state 7Li nuclear magnetic resonance (NMR) spectroscopy resolves the seven crystallographic Li sites in the crystalline compound into three main environments. The diffusion behavior of these Li environments as obtained from pulsed-field gradient NMR methods can be separated into one slow and one fast component. The rapid and tunable approach to the preparation of high quality "Li7P3S11" samples presented here coupled with detailed structural and compositional analysis opens the door to new and promising metastable solid electrolytes.

9.
Bioconjug Chem ; 30(11): 2771-2776, 2019 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-31603664

RESUMO

We present a new methodology for the generation of discrete molecularly dispersed enzyme-polymer-surfactant bioconjugates. Significantly, we demonstrate that >3-fold increase in the catalytic efficiency of the diffusion-limited phosphotriesterase arPTE can be achieved through sequential electrostatic addition of cationic and anionic polymer surfactants, respectively. Here, the polymer surfactants assemble on the surface of the enzyme via ion exchange to yield a compact corona. The observed rate enhancement is consistent with a mechanism whereby the polymer-surfactant corona gives rise to a decrease in the dielectric constant in the vicinity of the active site of the enzyme, accelerating the rate-determining product diffusion step. The facile methodology has significant potential for increasing the efficiency of enzymes and could therefore have a substantially positive impact for industrial enzymology.

10.
Am J Kidney Dis ; 74(1): 36-46, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30955944

RESUMO

RATIONALE & OBJECTIVE: The process of angiogenesis after kidney injury may determine recovery and long-term outcomes. We evaluated the association of angiogenesis markers with acute kidney injury (AKI) and mortality after cardiac surgery. STUDY DESIGN: Prospective cohort. SETTING & PARTICIPANTS: 1,444 adults undergoing cardiac surgery in the TRIBE-AKI (Translational Research Investigating Biomarker Endpoints for Acute Kidney Injury) cohort. EXPOSURES: Plasma concentrations of 2 proangiogenic markers (vascular endothelial growth factor A [VEGF] and placental growth factor [PGF]) and 1 antiangiogenic marker (soluble VEGF receptor 1 [VEGFR1]), measured pre- and postoperatively within 6 hours after surgery. OUTCOMES: AKI, long AKI duration (≥7 days), and 1-year all-cause mortality. ANALYTICAL APPROACH: Multivariable logistic regression. RESULTS: Following cardiac surgery, plasma VEGF concentrations decreased 2-fold, and PGF and VEGFR1 concentrations increased 1.5- and 8-fold, respectively. There were no meaningful associations of preoperative concentrations of angiogenic markers with outcomes of AKI and mortality. Higher postoperative VEGF and PGF concentrations were independently associated with lower odds of AKI (adjusted ORs of 0.89 [95% CI, 0.82-0.98] and 0.69 [95% CI, 0.55-0.87], respectively), long AKI duration (0.65 [95% CI, 0.49-0.87] and 0.48 [95% CI, 0.28-0.82], respectively), and mortality (0.74 [95% CI, 0.62-0.89] and 0.46 [95% CI, 0.31-0.68], respectively). In contrast, higher postoperative VEGFR1 concentrations were independently associated with higher odds of AKI (1.56; 95% CI, 1.31-1.87), long AKI duration (1.75; 95% CI, 1.09-2.82), and mortality (2.28; 95% CI, 1.61-3.22). LIMITATIONS: Angiogenesis markers were not measured after hospital discharge, so we were unable to determine long-term trajectories of angiogenesis marker levels during recovery and follow-up. CONCLUSIONS: Higher levels of postoperative proangiogenic markers, VEGF and PGF, were associated with lower AKI and mortality risk, whereas higher postoperative antiangiogenic VEGFR1 levels were associated with higher risk for AKI and mortality.


Assuntos
Lesão Renal Aguda , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Complicações Pós-Operatórias , Receptores de Fatores de Crescimento do Endotélio Vascular/sangue , Fator A de Crescimento do Endotélio Vascular/sangue , Lesão Renal Aguda/sangue , Lesão Renal Aguda/diagnóstico , Lesão Renal Aguda/etiologia , Lesão Renal Aguda/mortalidade , Idoso , Biomarcadores/sangue , Procedimentos Cirúrgicos Cardíacos/métodos , Creatinina/sangue , Determinação de Ponto Final , Feminino , Humanos , Rim/irrigação sanguínea , Masculino , Pessoa de Meia-Idade , Neovascularização Fisiológica , Avaliação de Resultados em Cuidados de Saúde , Complicações Pós-Operatórias/sangue , Complicações Pós-Operatórias/diagnóstico , Estudos Prospectivos , Medição de Risco , Estados Unidos/epidemiologia
11.
AIDS ; 33(4): 723-733, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30830887

RESUMO

OBJECTIVES: Urinary biomarkers of kidney injury may have potential to identify subclinical injury attributable to tenofovir disoproxil fumarate (TDF) toxicity. DESIGN: This observational study included 198 HIV-infected participants from the Multicenter AIDS Cohort Study and the Women's Interagency HIV Study, who initiated TDF between 2009 and 2015 and had urine samples collected at baseline before and after TDF initiation. METHODS: We used linear mixed-effects models controlling for urine creatinine and time on TDF to evaluate the effects of TDF initiation on changes in 14 urinary biomarkers. RESULTS: Within 1 year after TDF initiation, concentrations of trefoil factor 3 [+78%; 95% confidence interval (CI) +38%, +129%), alpha-1 microglobulin (α1m) (+32%; 95% CI +13%, +55%), clusterin (+21%; 95% CI +6%, +38%), uromodulin (+19%; 95% CI +4%, +36%), and kidney injury molecule-1 (KIM-1) (+13%; 95% CI +1%, +26%) significantly increased, whereas interleukin-18 (IL-18) significantly decreased (-13%, 95% CI -7%, -25%). Subsequent to the first year of TDF use, biomarker concentrations stabilized, and these changes were not statistically significant. When stratifying by baseline viremia (HIV-1 RNA < vs. ≥80 copies/ml), concentration changes for most biomarkers during the first year of TDF use were greater among aviremic vs. viremic participants, with significant differences in α1m (+80 vs. +22%), KIM-1 (+43 vs. +10%), beta-2 microglobulin (+83 vs. -10%), YKL-40 (+33 vs. -5%), and IL-18 (+20 vs. -27%). CONCLUSIONS: TDF initiation was associated with substantial changes in urinary biomarkers of kidney injury within the first year of use, particularly among aviremic participants. A urinary biomarker panel may be a clinically useful tool to detect and monitor the heterogeneous effects of TDF on the kidney.


Assuntos
Lesão Renal Aguda/induzido quimicamente , Fármacos Anti-HIV/efeitos adversos , Biomarcadores/urina , Infecções por HIV/tratamento farmacológico , Infecções por HIV/patologia , Tenofovir/efeitos adversos , Lesão Renal Aguda/patologia , Adulto , Fármacos Anti-HIV/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tenofovir/administração & dosagem , Urinálise
12.
Annu Rev Physiol ; 81: 309-333, 2019 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-30742783

RESUMO

The current unidimensional paradigm of kidney disease detection is incompatible with the complexity and heterogeneity of renal pathology. The diagnosis of kidney disease has largely focused on glomerular filtration, while assessment of kidney tubular health has notably been absent. Following insult, the kidney tubular cells undergo a cascade of cellular responses that result in the production and accumulation of low-molecular-weight proteins in the urine and systemic circulation. Modern advancements in molecular analysis and proteomics have allowed the identification and quantification of these proteins as biomarkers for assessing and characterizing kidney diseases. In this review, we highlight promising biomarkers of kidney tubular health that have strong underpinnings in the pathophysiology of kidney disease. These biomarkers have been applied to various specific clinical settings from the spectrum of acute to chronic kidney diseases, demonstrating the potential to improve patient care.


Assuntos
Lesão Renal Aguda/metabolismo , Biomarcadores/metabolismo , Insuficiência Renal Crônica/metabolismo , Animais , Humanos , Rim/metabolismo
13.
BMC Nephrol ; 20(1): 4, 2019 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-30606136

RESUMO

BACKGROUND: HIV-positive persons bear an excess burden of chronic kidney disease (CKD); however, conventional methods to assess kidney health are insensitive and non-specific for detecting early kidney injury. Urinary biomarkers can detect early kidney injury, and may help mitigate the risk of overt CKD. METHODS: Cross-sectional study of HIV-positive persons in the Multicenter AIDS Cohort Study and the Women's Interagency HIV Study. We measured levels of 14 biomarkers, capturing multiple dimensions of kidney injury. We then evaluated associations of known CKD risk factors with urine biomarkers using separate multivariable adjusted models for each biomarker. RESULTS: Of the 198 participants, one third were on HAART and virally suppressed. The vast majority (95%) had preserved kidney function as assessed by serum creatinine, with a median eGFR of 103 ml/min/1.73 m2 (interquartile range (IQR): 88, 116). In our multivariable analyses, the associations of each CKD risk factor with urinary biomarker levels varied in magnitude. For example, HIV viral load was predominantly associated with elevations in interleukin(IL)-18, and albuminuria, while higher CD4 levels were associated with lower monocyte chemoattractant protein-1 (MCP-1) and ß2-microglobulin. In contrast, older age was significantly associated with elevations in α1-microglobulin, kidney injury marker-1, clusterin, MCP-1, and chitinase-3-like protein-1 levels, as well as lower epidermal growth factor, and uromodulin levels. CONCLUSIONS: Among HIV-positive persons, CKD risk factors are associated with unique and heterogeneous patterns of changes in urine biomarkers levels. Additional work is needed to develop parsimonious algorithms that integrate multiple biomarkers and clinical data to discern the risk of overt CKD and its progression.


Assuntos
Biomarcadores/urina , Infecções por HIV/urina , Insuficiência Renal Crônica/urina , Terapia Antirretroviral de Alta Atividade , Comorbidade , Creatinina/sangue , Estudos Transversais , Diabetes Mellitus/epidemiologia , Feminino , Taxa de Filtração Glomerular , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Hepatite C/epidemiologia , Humanos , Hipertensão/epidemiologia , Masculino , Pessoa de Meia-Idade , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/epidemiologia , Fatores de Risco , Sensibilidade e Especificidade , Carga Viral , Viremia/complicações , Viremia/tratamento farmacológico , Viremia/urina
14.
Anal Biochem ; 566: 1-9, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30409761

RESUMO

A major hallmark of cancer is a perturbed metabolism resulting in high demand for various metabolites, glucose being the most well studied. While glucose can be converted into pyruvate for ATP production, the serine synthesis pathway (SSP) can divert glucose to generate serine, glycine, and methionine. In the process, the carbon unit from serine is incorporated into the one-carbon pool which makes methionine and maintains S-adenosylmethionine levels, which are needed to maintain the epigenetic landscape and ultimately controlling what genes are available for transcription. Alternatively, the carbon unit can be used for purine and thymidylate synthesis. We present here an approach to follow the flux through this pathway in cultured human cells using stable isotope enriched glucose and gas chromatography mass spectrometry analysis of serine, glycine, and methionine. We demonstrate that in three different cell lines this pathway contributes only 1-2% of total intracellular methionine. This suggests under high extracellular methionine conditions, the predominance of carbon units from this pathway are used to synthesize nucleic acids.


Assuntos
Aminoácidos/análise , Aminoácidos/metabolismo , Carbono/metabolismo , Glucose/metabolismo , Neoplasias/metabolismo , Isótopos de Carbono/química , Linhagem Celular Tumoral , Cromatografia Gasosa-Espectrometria de Massas/métodos , Glicina/metabolismo , Humanos , Metionina/metabolismo , Serina/metabolismo
15.
Free Radic Biol Med ; 133: 238-247, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30075191

RESUMO

Iron is one of the most abundant transition elements and is indispensable for almost all organisms. While the ability of iron to participate in redox chemistry is an essential requirement for participation in a range of vital enzymatic reactions, this same feature of iron also makes it dangerous in the generation of hydroxyl radicals and superoxide anions. Given the high local oxygen tensions in the lung, the regulation of iron acquisition, utilization, and storage therefore becomes vitally important, perhaps more so than in any other biological system. Iron plays a critical role in the biology of essentially every cell type in the lung, and in particular, changes in iron levels have important ramifications on immune function and the local lung microenvironment. There is substantial evidence that cigarette smoke causes iron dysregulation, with the implication that iron may be the link between smoking and smoking-related lung diseases. A better understanding of the connection between cigarette smoke, iron, and respiratory diseases will help to elucidate pathogenic mechanisms and aid in the identification of novel therapeutic targets.


Assuntos
Radical Hidroxila/metabolismo , Ferro/metabolismo , Pulmão/metabolismo , Fumar Tabaco/efeitos adversos , Humanos , Pulmão/patologia , Pneumopatias/etiologia , Pneumopatias/metabolismo , Pneumopatias/patologia , Oxirredução , Superóxidos/metabolismo
16.
Infect Immun ; 87(1)2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30297526

RESUMO

Rickettsiae can cause life-threatening infections in humans. Macrophages are one of the initial targets for rickettsiae after inoculation by ticks. However, it remains poorly understood how rickettsiae remain free in macrophages prior to establishing their infection in microvascular endothelial cells. Here, we demonstrated that the concentration of Rickettsia australis was significantly greater in infected tissues of Atg5flox/flox mice than in the counterparts of Atg5flox/flox Lyz-Cre mice, in association with a reduced level of interleukin-1ß (IL-1ß) in serum. The greater concentration of R. australis in Atg5flox/flox bone marrow-derived macrophages (BMMs) than in Atg5flox/flox Lyz-Cre BMMs in vitro was abolished by exogenous treatment with recombinant IL-1ß. Rickettsia australis induced significantly increased levels of light chain 3 (LC3) form II (LC3-II) and LC3 puncta in Atg5-competent BMMs but not in Atg5-deficient BMMs, while no p62 turnover was observed. Further analysis found the colocalization of LC3 with a small portion of R. australis and Rickettsia-containing double-membrane-bound vacuoles in the BMMs of B6 mice. Moreover, treatment with rapamycin significantly increased the concentrations of R. australis in B6 BMMs compared to those in the untreated B6 BMM controls. Taken together, our results demonstrate that Atg5 favors R. australis infection in mouse macrophages in association with a suppressed level of IL-1ß production but not active autophagy flux. These data highlight the contribution of Atg5 in macrophages to the pathogenesis of rickettsial diseases.


Assuntos
Proteína 5 Relacionada à Autofagia/metabolismo , Interações Hospedeiro-Patógeno , Macrófagos/metabolismo , Macrófagos/microbiologia , Rickettsia/crescimento & desenvolvimento , Animais , Células Cultivadas , Feminino , Interleucina-1beta/metabolismo , Camundongos Endogâmicos C57BL , Rickettsiose do Grupo da Febre Maculosa
17.
Ann Intern Med ; 169(9): 610-618, 2018 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-30357395

RESUMO

Background: Whether the increased incidence of chronic kidney disease (CKD) during intensive systolic blood pressure (SBP) lowering is accompanied by intrinsic kidney injury is unknown. Objective: To compare changes in kidney damage biomarkers between incident CKD case participants and matched control participants as well as between case participants in the intensive (<120 mm Hg) versus the standard (<140 mm Hg) SBP management groups of SPRINT (Systolic Blood Pressure Intervention Trial). Design: Nested case-control study within SPRINT. Setting: Adults with hypertension without baseline kidney disease. Participants: Case participants (n = 162), who developed incident CKD during trial follow-up (128 in the intensive and 34 in the standard group), and control participants (n = 162) without incident CKD, who were matched on age, sex, race, baseline estimated glomerular filtration rate, and randomization group. Measurements: 9 urinary biomarkers of kidney damage were measured at baseline and at 1 year. Linear mixed-effects models were used to estimate 1-year biomarker changes. Results: Higher concentrations of urinary albumin, kidney injury molecule-1, and monocyte chemoattractant protein-1 at baseline were significantly associated with greater odds of incident CKD (adjusted odds ratio per doubling: 1.50 [95% CI, 1.14 to 1.98], 1.51 [CI, 1.05 to 2.17], and 1.70 [CI, 1.13 to 2.56], respectively). After 1 year of blood pressure intervention, incident CKD case participants in the intensive group had significantly greater decreases in albumin-creatinine ratio (ACR), interleukin-18, anti-chitinase-3-like protein 1 (YKL-40), and uromodulin than the matched control participants. Compared with case participants in the standard group, those in the intensive group had significantly greater decreases in ACR, ß2-microglobulin, α1-microglobulin, YKL-40, and uromodulin. Limitation: Biomarker measurements were available only at baseline and 1 year. Conclusion: Incident CKD in the setting of intensive SBP lowering was accompanied by decreases, rather than elevations, in levels of kidney damage biomarkers and thus may reflect benign changes in renal blood flow rather than intrinsic injury. Primary Funding Source: National Institute for Diabetes and Digestive and Kidney Diseases.


Assuntos
Anti-Hipertensivos/uso terapêutico , Biomarcadores/urina , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Insuficiência Renal Crônica/diagnóstico , Idoso , Albuminúria/urina , alfa-Globulinas/urina , Estudos de Casos e Controles , Quimiocina CCL2/urina , Proteína 1 Semelhante à Quitinase-3/urina , Creatinina/urina , Feminino , Taxa de Filtração Glomerular , Receptor Celular 1 do Vírus da Hepatite A/metabolismo , Humanos , Interleucina-18/urina , Lipocalina-2/urina , Masculino , Pessoa de Meia-Idade , Circulação Renal , Insuficiência Renal Crônica/etiologia , Insuficiência Renal Crônica/urina , Fatores de Risco , Uromodulina/urina , Microglobulina beta-2/urina
18.
Nat Commun ; 9(1): 3900, 2018 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-30254369

RESUMO

Developments in computational chemistry, bioinformatics, and laboratory evolution have facilitated the de novo design and catalytic optimization of enzymes. Besides creating useful catalysts, the generation and iterative improvement of designed enzymes can provide valuable insight into the interplay between the many phenomena that have been suggested to contribute to catalysis. In this work, we follow changes in conformational sampling, electrostatic preorganization, and quantum tunneling along the evolutionary trajectory of a designed Kemp eliminase. We observe that in the Kemp Eliminase KE07, instability of the designed active site leads to the emergence of two additional active site configurations. Evolutionary conformational selection then gradually stabilizes the most efficient configuration, leading to an improved enzyme. This work exemplifies the link between conformational plasticity and evolvability and demonstrates that residues remote from the active sites of enzymes play crucial roles in controlling and shaping the active site for efficient catalysis.


Assuntos
Domínio Catalítico , Desenho Assistido por Computador , Evolução Molecular Direcionada , Enzimas/química , Cristalografia por Raios X , Estabilidade Enzimática , Enzimas/genética , Enzimas/metabolismo , Isoxazóis/química , Isoxazóis/metabolismo , Modelos Químicos , Simulação de Dinâmica Molecular , Estrutura Molecular , Eletricidade Estática , Termodinâmica
19.
Clin J Am Soc Nephrol ; 13(9): 1321-1329, 2018 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-30154221

RESUMO

BACKGROUND AND OBJECTIVES: Tenofovir disoproxil fumarate (tenofovir) is associated with elevated concentrations of biomarkers of kidney damage and dysfunction in individuals with HIV. The relationship of these kidney biomarkers with longitudinal kidney function decline is unknown. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We evaluated associations of 14 urinary biomarkers of kidney injury with changes in eGFR among 198 men and women with HIV who initiated tenofovir between 2009 and 2015 in the Multicenter AIDS Cohort Study and Women's Interagency HIV Study. Urinary biomarkers included albumin-to-creatinine ratio, α-1-microglobulin, ß-2-microglobulin, cystatin C, kidney injury molecule-1 (KIM-1), IL-18, neutrophil gelatinase-associated lipocalin (NGAL), clusterin, osteopontin, uromodulin, monocyte chemoattractant protein-1, EGF, trefoil factor 3, and chitinase 3-like protein 1. We used multivariable linear mixed-effect models controlling for demographics, traditional kidney disease risk factors, and HIV-related risk factors to evaluate associations of baseline biomarkers with first-year changes in eGFR, and associations of year 1 and first-year change in biomarkers with changes in eGFR from year 1 to year 3. We used the least absolute shrinkage and selection operator method to identify a parsimonious set of biomarkers jointly associated with changes in eGFR. RESULTS: Median eGFR before tenofovir initiation was 103 (interquartile range, 88-116) ml/min per 1.73 m2. During the first year of tenofovir use, eGFR decreased on average by 9.2 (95% confidence interval, 6.5 to 11.9) ml/min per 1.73 m2 and was stable afterward (decrease of 0.62; 95% confidence interval, -0.85 to 2.1 ml/min per 1.73 m2 per year). After multivariable adjustment, higher baseline ß-2-microglobulin, KIM-1, and clusterin were associated with larger first-year eGFR declines, whereas higher baseline uromodulin was associated with a smaller eGFR decline. First-year increase in urinary cystatin C and higher year 1 IL-18 were associated with larger annual eGFR declines from year 1 to year 3. The parsimonious models identified higher pre-tenofovir clusterin and KIM-1, lower pre-tenofovir uromodulin, and higher year 1 IL-18 as jointly associated with larger eGFR declines. CONCLUSIONS: Urinary biomarkers of kidney injury measured before and after tenofovir initiation are associated with subsequent changes in eGFR in individuals with HIV. PODCAST: This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2018_08_28_CJASNPodcast_18_9_S.mp3.


Assuntos
Fármacos Anti-HIV/efeitos adversos , Taxa de Filtração Glomerular , Infecções por HIV/tratamento farmacológico , Infecções por HIV/fisiopatologia , Nefropatias/induzido quimicamente , Nefropatias/fisiopatologia , Tenofovir/efeitos adversos , Adulto , Fármacos Anti-HIV/uso terapêutico , Biomarcadores/urina , Feminino , Infecções por HIV/complicações , Infecções por HIV/urina , Humanos , Nefropatias/urina , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Tenofovir/uso terapêutico
20.
Nat Chem Biol ; 14(9): 861-869, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30061718

RESUMO

Fluorescent sensors are an essential part of the experimental toolbox of the life sciences, where they are used ubiquitously to visualize intra- and extracellular signaling. In the brain, optical neurotransmitter sensors can shed light on temporal and spatial aspects of signal transmission by directly observing, for instance, neurotransmitter release and spread. Here we report the development and application of the first optical sensor for the amino acid glycine, which is both an inhibitory neurotransmitter and a co-agonist of the N-methyl-D-aspartate receptors (NMDARs) involved in synaptic plasticity. Computational design of a glycine-specific binding protein allowed us to produce the optical glycine FRET sensor (GlyFS), which can be used with single and two-photon excitation fluorescence microscopy. We took advantage of this newly developed sensor to test predictions about the uneven spatial distribution of glycine in extracellular space and to demonstrate that extracellular glycine levels are controlled by plasticity-inducing stimuli.


Assuntos
Corantes Fluorescentes/química , Glicina/análise , Hipocampo/química , Animais , Células Cultivadas , Transferência Ressonante de Energia de Fluorescência , Corantes Fluorescentes/síntese química , Células HEK293 , Humanos , Masculino , Imagem Óptica , Ratos , Ratos Wistar
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