skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Title: Copper deficiency is an independent risk factor for mortality in patients with advanced liver disease
Background and Aim:Copper is an essential trace metal serving as a cofactor in innate immunity, metabolism, and iron transport. We hypothesize that copper deficiency may influence survival in patients with cirrhosis through these pathways. Methods:We performed a retrospective cohort study involving 183 consecutive patients with cirrhosis or portal hypertension. Copper from blood and liver tissues was measured using inductively coupled plasma mass spectrometry. Polar metabolites were measured using nuclear magnetic resonance spectroscopy. Copper deficiency was defined by serum or plasma copper below 80 µg/dL for women or 70 µg/dL for men. Results:The prevalence of copper deficiency was 17% (N=31). Copper deficiency was associated with younger age, race, zinc and selenium deficiency, and higher infection rates (42% vs. 20%,p=0.01). Serum copper correlated positively with albumin, ceruloplasmin, hepatic copper, and negatively with IL-1β. Levels of polar metabolites involved in amino acids catabolism, mitochondrial transport of fatty acids, and gut microbial metabolism differed significantly according to copper deficiency status. During a median follow-up of 396 days, mortality was 22.6% in patients with copper deficiency compared with 10.5% in patients without. Liver transplantation rates were similar (32% vs. 30%). Cause-specific competing risk analysis showed that copper deficiency was associated with a significantly higher risk of death before transplantation after adjusting for age, sex, MELD-Na, and Karnofsky score (HR: 3.40, 95% CI, 1.18–9.82,p=0.023). Conclusions:In advanced cirrhosis, copper deficiency is relatively common and is associated with an increased infection risk, a distinctive metabolic profile, and an increased risk of death before transplantation.  more » « less
Award ID(s):
2018388
PAR ID:
10482190
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ;
Publisher / Repository:
Wolters Kluwer Health, Inc.
Date Published:
Journal Name:
Hepatology Communications
Volume:
7
Issue:
3
ISSN:
2471-254X
Page Range / eLocation ID:
e0076 to e0076
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Background:It is a major clinical challenge to ensure the long-term function of transplanted kidneys. Specifically, the injury associated with cold storage of kidneys compromises the long-term function of the grafts after transplantation. Therefore, the molecular mechanisms underlying cold-storage–related kidney injury are attractive therapeutic targets to prevent injury and improve long-term graft function. Previously, we found that constitutive proteasome function was compromised in rat kidneys after cold storage followed by transplantation. Here, we evaluated the role of the immunoproteasome (iproteasome), a proteasome variant, during cold storage (CS) followed by transplantation. Methods:Established in vivo rat kidney transplant model with or without CS containing vehicle or iproteasome inhibitor (ONX 0914) was used in this study. Theiproteasome function was performed using rat kidney homogenates and fluorescent-based peptide substrate specific to β5i subunit. Western blotting and quantitative RT-PCR were used to assess the subunit expression/level of theiproteasome (β5i) subunit. Results:We demonstrated a decrease in the abundance of the β5i subunit of theiproteasome in kidneys during CS, but β5i levels increased in kidneys after CS and transplant. Despite the increase in β5i levels and its peptidase activity within kidneys, inhibiting β5i during CS did not improve graft function after transplantation. Summary:These results suggest that the pharmacological inhibition of immunoproteasome function during CS does not improve graft function or outcome. In light of these findings, future studies targeting immunoproteasomes during both CS and transplantation may define the role of immunoproteasomes on short- and long-term kidney transplant outcomes. 
    more » « less
  2. Kendall, Melissa M (Ed.)
    ABSTRACT Bacteria can change morphology in response to stressors and changes in their environment, including infection of a host. We previously identified the bacterial species,Bordetella atropi, which uses nutrient-induced filamentation as a novel mechanism for cell-to-cell spreading in the intestinal epithelial cells of a nematode host. To further investigate the conservation of nutrient-induced filamentation in Bordetellae, we utilized the turkey-infecting speciesBordetella avium,which filamentsin vitrowhen switched from a standard growth media to an enriched media. We conducted a selection-based filamentation screen withB. aviumand isolated two independent non-filamentous mutants that failed to filament in highly enriched media. These mutants contained different alleles inbvgS,the sensor in the two-component master virulence regulator (BvgAS) conserved across theBordetellagenus. To investigate the role ofbvgSin nutrient-induced filamentation, we conducted transcriptomics and found that our allele ofbvgSresulted in loss of responsiveness to highly enriched media, especially in genes related to nutrient uptake and metabolism. The most dysregulated gene in thebvgSmutant encoded for succinyl-CoA:acetate CoA-transferase, and we were able to regulate filamentation with exogenous metabolites up and downstream of this enzyme. These data suggest thatbvgSregulates nutrient-induced filamentation by controlling metabolic capacity. Overall, we found that the virulence regulatorbvgScan control nutrient-induced filamentation inB. avium,suggesting there may be conservation in Bordetellae for utilizing this morphological change as a virulence phenotype.IMPORTANCEBordetella aviumis the causative agent of bordetellosis, an infectious disease affecting the respiratory system of birds, significantly increasing morbidity in poultry, ultimately leading to economic losses. It is long known that the pathogenesis ofB. aviumis governed by the two-component master virulence regulator, BvgAS. However, this regulon has never before been associated with nutrient-induced filamentation. In this study, we identify BvgS to be regulating nutrient-induced filamentation. We also report the first transcriptomics analysis of filamentousB. avium, showing the enzyme succinyl-CoA:acetate CoA-transferase may be involved in a metabolic shift in enriched nutrient conditions leading to filamentation. Our results suggest that virulence inB. aviumis a dynamic relationship, affected by nutrient availability, rather than a simple binary decision. 
    more » « less
  3. Précis:Capillary and neuronal tissue loss occur both globally and with regional specificity in pre-perimetric glaucoma patients at the level of the optic nerve and macula, with perifovea regions affected earlier than parafovea areas. Purpose:To investigate optic nerve head (ONH) and macular vessel densities (VD) and structural parameters assessed by optical coherence tomography angiography in pre-perimetric open angle glaucoma (ppOAG) patients and healthy controls. Materials and Methods:In all, 113 healthy and 79 ppOAG patients underwent global and regional (hemispheric/quadrants) assessments of retinal, ONH, and macular vascularity and structure, including ONH parameters, retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) thickness. Comparisons between outcomes in ppOAG and controls were adjusted for age, sex, race, BMI, diabetes, and hypertension, withP<0.05 considered statistically significant. Results:In ppOAG compared with healthy controls: RNFL thicknesses were statistically significantly lower for all hemispheres, quadrants, and sectors (P<0.001–0.041); whole image peripapillary all and small blood vessels VD were statistically significantly lower for all the quadrants (P<0.001–0.002), except for the peripapillary small vessels in the temporal quadrant (ppOAG: 49.66 (8.40), healthy: 53.45 (4.04);P=0.843); GCC and inner and full macular thicknesses in the parafoveal and perifoveal regions were significantly lower in all the quadrants (P=0.000–P=0.033); several macular VD were significantly lower (P=0.006–0.034), with the exceptions of macular center, parafoveal superior and inferior quadrant, and perifoveal superior quadrant (P>0.05). Conclusions:In ppOAG patients, VD biomarkers in both the macula and ONH, alongside RNFL, GCC, and macular thickness, were significantly reduced before detectable visual field loss with regional specificity. The most significant VD reduction detected was in the peripheric (perifovea) regions. Macular and ONH decrease in VD may serve as early biomarkers of glaucomatous disease. 
    more » « less
  4. Claesen, Jan (Ed.)
    ABSTRACT The human skin microbiome is a diverse ecosystem that can help prevent infections by producing biomolecules and peptides that inhibit growth and virulence of bacterial pathogens.Staphylococcus aureusis a major human pathogen responsible for diseases that range from acute skin and soft tissue infections to life-threatening septicemia. Its ability to form biofilms is a key virulence factor contributing to its success as a pathogen as well as to its increased antimicrobial resistance. Here, we investigated the ability of bacterial skin commensals to produce molecules that inhibitS. aureusbiofilm formation. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) identified 77 human skin microbiome bacterial isolates fromStaphylococcusandBacillusgenera. Metabolites from cell-free concentrated media (CFCM) from 26 representative isolates were evaluated for their ability to inhibit biofilm formation by both methicillin-resistant (MRSA) and methicillin-sensitive (MSSA)S. aureusstrains. CFCM, derived from most of the isolates, inhibited biofilm formation to varying extents but did not inhibit planktonic growth ofS. aureus. Size fractionation of the CFCM of threeS.epidermidisisolates indicated that they produce different bioactive molecules. Cluster analysis, based on either MALDI-TOF mass spectra or whole-genome sequencing draft genomes, did not show clear clusters associated with levels of biofilm inhibition amongS. epidermidisstrains. Finally, similar biosynthetic gene clusters were detected in allS. epidermidisstrains analyzed. These findings indicate that several bacterial constituents of the human skin microbiome display antibiofilmin vitroactivity, warranting further investigation on their potential as novel therapeutic agents. IMPORTANCEThe skin is constantly exposed to the environment and consequently to numerous pathogens. The bacterial community that colonizes healthy skin is thought to play an important role in protecting us against infections.S. aureusis a leading cause of death worldwide and is frequently involved in several types of infections, including skin and soft tissue infections. Its ability to adhere to surfaces and produce biofilms is considered an important virulence factor. Here, we analyzed the activity of different species of bacteria isolated from healthy skin onS. aureusbiofilm formation. We found that some species ofStaphylococcusandBacilluscan reduceS. aureusbiofilm formation, although a generally lower level of inhibitory activity was observed compared toS. epidermidisisolates. AmongS. epidermidisisolates, strength of activity was dependent on the strain. Our data highlight the importance of mining the skin microbiome for isolates that could help combat skin pathogens. 
    more » « less
  5. Goldman, Gustavo H (Ed.)
    ABSTRACT Infections caused by the emerging pathogenic yeastClavispora (Candida) lusitaniaecan be difficult to manage due to multi-drug resistance. Resistance to the frontline antifungal fluconazole (FLZ) inCandidaspp. is commonly acquired through gain-of-function (GOF) mutations in the gene encoding the transcription factor Mrr1. These activated Mrr1 variants enhance FLZ efflux via upregulation of the multi-drug transporter geneMDR1. Recently, it was reported that, unlike in the well-studiedCandida albicansspecies,C. lusitaniaeandCandida parapsilosiswith activated Mrr1 also have high expression ofCDR1, which encodes another multi-drug transporter with overlapping but distinct transported substrate profiles and Cdr1-dependent FLZ resistance. To better understand the mechanisms of Mrr1 regulation ofMDR1andCDR1, and other co-regulated genes, we performed Cleavage Under Targets and Release Using Nuclease (CUT&RUN) analysis of Mrr1 binding sites. Mrr1 bound the promoter regions ofMDR1andCDR1, as well asFLU1, which encodes another transporter capable of FLZ efflux. Mdr1 and Cdr1 independently contributed to the decreased susceptibility of theMRR1GOFstrains against diverse clinical azoles and other antifungals, including 5-flucytosine. A consensus motif, CGGAGWTAR, enriched in Mrr1-boundC. lusitaniaeDNA was also conserved upstream ofMDR1andCDR1across species, includingC. albicans. CUT&RUN and RNA-seq data were used to define the Mrr1 regulon, which includes genes involved in transport, stress response, and metabolism. Activated and inducible Mrr1 bound similar regions in the promoters of Mrr1 regulon genes. Our studies provide new evolutionary insights into the coordinated regulation of multi-drug transporters and potential mechanism(s) that aid secondary resistance acquisition in emergingCandida. IMPORTANCEUnderstanding antifungal resistance in emergingCandidapathogens is essential to managing treatment failures and guiding the development of new therapeutic strategies. Like otherCandidaspecies, the environmental opportunistic fungal pathogenClavispora(Candida)lusitaniaecan acquire resistance to the antifungal fluconazole by overexpression of the multi-drug efflux pump Mdr1 through gain-of-function (GOF) mutations in the gene encoding the transcription factor Mrr1. Here, we show thatC. lusitaniaeMrr1 also directly regulatesCDR1, another major multi-drug transporter gene, along withMDR1. In strains with activated Mrr1, upregulation ofMDR1andCDR1protects against diverse antifungals, potentially aiding the rise of other resistance mutations. Mrr1 also regulates several stress response and metabolism genes, thereby providing new perspectives into the physiology of drug-resistant strains. The identification of an Mrr1 binding motif that is conserved across strains and species will advance future efforts to understand multi-drug resistance acrossCandidaspecies. 
    more » « less