Glucose is vital for life, serving as both a source of energy and carbon building block for growth. When glucose is limiting, alternative nutrients must be harnessed. To identify mechanisms by which ...cells can tolerate complete loss of glucose, we performed nutrient-sensitized genome-wide genetic screens and a PRISM growth assay across 482 cancer cell lines. We report that catabolism of uridine from the medium enables the growth of cells in the complete absence of glucose. While previous studies have shown that uridine can be salvaged to support pyrimidine synthesis in the setting of mitochondrial oxidative phosphorylation deficiency
, our work demonstrates that the ribose moiety of uridine or RNA can be salvaged to fulfil energy requirements via a pathway based on: (1) the phosphorylytic cleavage of uridine by uridine phosphorylase UPP1/UPP2 into uracil and ribose-1-phosphate (R1P), (2) the conversion of uridine-derived R1P into fructose-6-P and glyceraldehyde-3-P by the non-oxidative branch of the pentose phosphate pathway and (3) their glycolytic utilization to fuel ATP production, biosynthesis and gluconeogenesis. Capacity for glycolysis from uridine-derived ribose appears widespread, and we confirm its activity in cancer lineages, primary macrophages and mice in vivo. An interesting property of this pathway is that R1P enters downstream of the initial, highly regulated steps of glucose transport and upper glycolysis. We anticipate that 'uridine bypass' of upper glycolysis could be important in the context of disease and even exploited for therapeutic purposes.
Alcohol-associated liver disease (ALD) is one of the most devastating complications of alcohol use disorder (AUD), an increasingly prevalent condition. Medical addiction therapy for AUD may play a ...role in protecting against the development and progression of ALD.
To ascertain whether medical addiction therapy was associated with an altered risk of developing ALD in patients with AUD.
This retrospective cohort study used the Mass General Brigham Biobank, an ongoing research initiative that had recruited 127 480 patients between its start in 2010 and August 17, 2021, when data for the present study were retrieved. The mean follow-up duration from AUD diagnosis was 9.2 years. International Statistical Classification of Diseases and Related Health Problems, Tenth Revision diagnosis codes were used to identify ALD and AUD diagnoses.
Medical addiction therapy was defined as the documented use of disulfiram, acamprosate, naltrexone, gabapentin, topiramate, or baclofen. Patients were considered to be treated if they initiated medical addiction therapy before the relevant outcome.
Adjusted odds ratios (aORs) for the development of ALD and hepatic decompensation were calculated and adjusted for multiple risk factors.
The cohort comprised 9635 patients with AUD, of whom 5821 were male individuals (60.4%), and the mean (SD) age was 54.8 (16.5) years. A total of 1135 patients (11.8%) had ALD and 3906 patients (40.5%) were treated with medical addiction therapy. In multivariable analyses, medical addiction therapy for AUD was associated with decreased incidence of ALD (aOR, 0.37; 95% CI, 0.31-0.43; P < .001). This association was evident for naltrexone (aOR, 0.67; 95% CI, 0.46-0.95; P = .03), gabapentin (aOR, 0.36; 95% CI, 0.30-0.43; P < .001), topiramate (aOR, 0.47; 95% CI, 0.32-0.66; P < .001), and baclofen (aOR, 0.57; 95% CI, 0.36-0.88; P = .01). In addition, pharmacotherapy for AUD was associated with lower incidence of hepatic decompensation in patients with cirrhosis (aOR, 0.35; 95% CI, 0.23-0.53, P < .001), including naltrexone (aOR, 0.27; 95% CI, 0.10-0.64; P = .005) and gabapentin (aOR, 0.36; 95% CI, 0.23-0.56; P < .001). This association persisted even when medical addiction therapy was initiated only after the diagnosis of cirrhosis (aOR, 0.41; 95% CI, 0.23-0.71; P = .002).
Results of this study showed that receipt of medical addiction therapy for AUD was associated with reduced incidence and progression of ALD. The associations of individual pharmacotherapy with the outcomes of ALD and hepatic decompensation varied widely.
Many DNA nanostructures have been produced and a wide range of potential applications have been proposed. However, confirmation of accurate 3D construction is particularly challenging. Here, we ...demonstrate that cryoEM may be exploited to obtain structural information at sufficient resolution to visualize the DNA helix and reveal the absolute stereochemistry of a 7 nm self-assembled DNA tetrahedron. Structural analysis at such high resolution by cryoEM image analysis is unprecedented for any biological molecule of this size.
While alcohol use has been shown to increase serum HDL, advanced liver disease associates with decreased serum HDL. The combined influence of alcohol consumption and liver fibrosis is poorly defined. ...In this study, we sought to investigate the competing effects of alcohol use and hepatic fibrosis on serum HDL and to determine if the presence of advanced hepatic fibrosis ablates the reported effect of alcohol consumption on serum HDL. We performed a cross-sectional, exploratory analysis examining the interaction between alcohol use and advanced hepatic fibrosis on serum HDL levels in 10,528 patients from the Partners Biobank. Hepatic fibrosis was assessed using the FIB-4 index. We excluded patients with baseline characteristics that affect serum HDL, independent of alcohol use or the presence or advanced hepatic fibrosis. We observed an incremental correlation between increasing HDL levels and amount of alcohol consumed (
P
< 0.0001), plateauing in those individuals who drink 1–2 drinks per day, Contrastingly, we found a negative association between the presence of advanced hepatic fibrosis and lower HDL levels, independent of alcohol use (beta coefficient: -0.011075, SEM0.003091,
P
value: 0.0001). Finally, when comparing subjects with advanced hepatic fibrosis who do not use alcohol to those who do, we observed that alcohol use is associated with increased HDL levels (54.58 mg/dL vs 67.26 mg/dL,
p
= 0.0009). This HDL-elevating effect of alcohol was more pronounced than that seen in patients without evidence of advanced hepatic fibrosis (60.88 mg/dL vs 67.93 mg/dL,
p
< 0.0001). Our data suggest that the presence of advanced hepatic fibrosis does not blunt the HDL-elevating effect of alcohol use.
A simple modification allows DNA to be linked to recombinant proteins. DNA functionalized with three nitrilotriacetic acid groups forms coordination complexes with nickel ions and the His₆-tag of the ...recombinant protein (here, GFP). This noncovalent linkage is reversible, site-specific and has a high (nanomolar) affinity.We present a facile method for linking recombinant proteins to DNA. It is based on the nickel-mediated interaction between a hexahistidine tag (His₆-tag) and DNA functionalized with three nitrilotriacetic acid (NTA) groups. The resulting DNA-protein linkage is site-specific. It can be broken quickly and controllably by the addition of a chelating agent that binds nickel. We have used this new linker to bind proteins to a variety of DNA motifs commonly used in the fabrication of nanostructures by DNA self-assembly.
Substance use disorder (SUD) commonly associates with alcohol use disorder (AUD), and certain substances have independently been shown to drive liver injury. In this work, we sought to determine if ...coexisting SUD in patients with AUD is associated with the presence of alcohol-associated liver disease (ALD).
We performed a cross-sectional analysis using the Mass General Brigham Biobank to identify patients based on International Classification of Diseases, Tenth Revision, codes. We performed multivariate analyses accounting for a wide range of demographic and clinical variables to evaluate the association between SUD and ALD. We subsequently used the same method to evaluate the association between SUD and hepatic decompensation.
We identified 2848 patients with a diagnosis of AUD; 9.0% of them had ALD, and 25.2% had a history of SUD. In multivariate analyses, patients with SUD were more frequently diagnosed with ALD than those without SUD (odds ratio OR = 1.95, P = .001). Furthermore, the number of concurrent SUDs was positively associated with the diagnosis of ALD (OR = 1.33, P < .001). Independent of the presence of other SUDs, opioid use disorder in patients with AUD was associated with ALD (OR = 1.902, P = .02). In subsequent analyses, we found that sedative use disorder was associated with hepatic decompensation (OR = 2.068, P = .03).
In patients with AUD, SUD, and particularly opioid use disorder, was independently associated with the diagnosis of ALD.
We hypothesized that fibroblast growth factor-21 (FGF-21) would be highly expressed in patients with alcohol-associated hepatitis (AH) and could be a novel and biologically relevant predictive ...biomarker to reliably distinguish severe AH and decompensated alcohol-associated cirrhosis (AC).
We identified a discovery cohort of 88 subjects with alcohol-associated liver disease (ALD) of varying disease severity from our ALD repository. Our validation cohort consisted of 37 patients with a biopsy-proven diagnosis of AH, AC, or absence of ALD with Model for End-Stage Liver Disease scores ≥10. Serum from both groups during index hospitalization was assayed for FGF-21 by ELISA. We performed receiver operating characteristic analysis and prediction modeling in both cohorts to discriminate between AH and AC in high Model for End-Stage Liver Disease (≥20) patients.
In both cohorts, FGF-21 concentrations were highest in subjects with moderate to severe AH compared with those having alcohol use disorder or AC (mean: 2,609 pg/mL, P < 0.0001). The discovery cohort area under the curve of FGF-21 between AH and AC was 0.81 (95% confidence interval: 0.65-0.98, P < 0.01). In the validation cohort, FGF-21 levels were higher in severe AH compared with AC (3,052 vs 1,235 pg/mL, P = 0.03), and the area under the curve was 0.76 (95% confidence interval: 0.56-0.96, P < 0.03). A survival analysis showed that patients with FGF-21 serum levels in the second interquartile had the highest survival compared with all other quartiles.
FGF-21 performs well as a predictive biomarker to distinguish severe AH from AC and may be helpful in the management and clinical investigation of patients with severe alcohol-associated liver diseases.
Diagnostic challenges continue to impede development of effective therapies for successful management of alcohol-associated hepatitis (AH), creating an unmet need to identify noninvasive biomarkers ...for AH. In murine models, complement contributes to ethanol-induced liver injury. Therefore, we hypothesized that complement proteins could be rational diagnostic/prognostic biomarkers in AH. Here, we performed a comparative analysis of data derived from human hepatic and serum proteome to identify and characterize complement protein signatures in severe AH (sAH). The quantity of multiple complement proteins was perturbed in liver and serum proteome of patients with sAH. Multiple complement proteins differentiated patients with sAH from those with alcohol cirrhosis (AC) or alcohol use disorder (AUD) and healthy controls (HCs). Serum collectin 11 and C1q binding protein were strongly associated with sAH and exhibited good discriminatory performance among patients with sAH, AC, or AUD and HCs. Furthermore, complement component receptor 1-like protein was negatively associated with pro-inflammatory cytokines. Additionally, lower serum MBL associated serine protease 1 and coagulation factor II independently predicted 90-day mortality. In summary, meta-analysis of proteomic profiles from liver and circulation revealed complement protein signatures of sAH, highlighting a complex perturbation of complement and identifying potential diagnostic and prognostic biomarkers for patients with sAH.
PDF
