Abstract 100: Integrated Cardiac Metabolism In End-Stage Human Heart Failure

Heart failure affects millions of people worldwide with mortality near 50% within five years. This disease is characterized by widespread cardiac and systemic metabolic changes, but a comprehensive evaluation of metabolism in failing human hearts is lacking. Here, we provide a comprehensive depiction of cardiac and systemic metabolic changes in 89 explanted failing and non-failing human hearts through integration of plasma and cardiac tissue metabolomics, genome-wide RNAseq, and proteomic data. The data confirm a profound bioenergetic defect in end-stage human heart failure and demonstrate extensive changes in metabolic homeostasis. The data indicate a substantial defect in fatty acid (FA) use in failing hearts, in particular unsaturated FAs. Reduction of FAs and acyl-carnitines in failing tissue in contrast to concomitant elevations in plasma suggest a defect in import of FAs into the cell, rather than a defect in FA oxidation. Intermediates of glycolysis, the pentose phosphate pathway, and glycogen synthesis are all similarly reduced, as is expression of GLUT1, indicating diminished glucose uptake. However, there was no significant change in tissue pyruvate content, suggesting an increase in lactate utilization. The data suggest increased flux of pyruvate into mitochondria, likely promoting pyruvate oxidation but not pyruvate carboxylation. Blunted anabolic pyruvate flux, in turn, likely leads to insufficient TCA cycle intermediates. Ketone levels were increased in both failing tissue and plasma, as previously reported. The phospholipid content of failing human hearts is greatly increased in both failing tissue and plasma. Nucleotide synthesis pathways also appear to be reprogrammed, with a notable decrease in adenosine metabolism, specifically. Together, these data indicate widespread change in the local cardiac and greater systemic metabolic landscape in severe human heart failure.

What do Clinical Trials Tell us About Antidepressant Delayed Onset of Action?

Response to antidepressants in major depressive disorder is highly variable and determinants are not well understood. Presentation will provide clinical trial data on time to response and determinants of response to antidepressant treatment. Data is from the Innovative Medicines Initiative funded NEWMEDS collaboration, a large public-private collaboration which assembled the largest dataset of individual patient level information from randomized placebo-controlled trials of antidepressant drugs. Studies were conducted by four large pharmaceutical companies. Dataset includes placebo-controlled trials of citalopram, duloxetine, escitalopram, quetiapine and sertraline in adults with MDD. We examined patient and trial-design-related determinants of outcome as measured by change on Hamilton Depression Scale or Montgomery–Asberg Depression Rating Scale in 34 placebo-controlled trials (drug, n = 8260; placebo, n = 3957). While it is conventional for trials to be 6–8 weeks long, data presented will show that drug-placebo differences were observable at week 4 with nearly the same sensitivity and lower dropout rates. Having any of these attributes was significantly associated with greater drug vs. placebo differences on symptom improvement: female, patients being middle aged, increasing proportion of patients on placebo, excluding all patients from centers with high placebo response regardless of active treatment response, using active run in periods and including self-report measures. Proof of concept trials can be shorter and efficiency improved by selecting enriched populations based on clinical and demographic variables, ensuring adequate balance of placebo patients, and carefully selecting and monitoring centers. In addition to improving drug discovery, patient exposure to placebo and experimental treatments can be reduced.

Disclosure of interest

I have received research grant(s) support and/or travel support and/or speaker fees and/or consultant fees from Takeda, Minerva, Intra-cellular Therapies, Janssen (J&J), Eli Lilly, Pfizer, BiolineRx, Roche, Abraham Pharmaceuticals, Pierre Fabre, Minerva and Amgen.

Usefulness of interim analyses in portending study results in antipsychotic and antidepressant trials

It is unknown whether interim analyses portend final study results. Fatigue, pressure to complete trials and recruitment differences may mitigate against this. We examined the similarity of efficacy results of the first and second half of recruited patients to complete trials and explore possible intervening variables. Using data from the NewMeds repository of patient level data from placebo-controlled randomized trials of antipsychotics (AP) (22 studies, n=7056) and antidepressants (AD) (39 studies, n=12,217) we compared treatment effect size (placebo vs. active treatment) of the first and second half of patients recruited in completed trials. We found that in AP studies median difference in treatment effect between cohorts was -0.03, indicating that overall first and second cohorts yielded similar results. In AD studies, median difference between cohorts was 0.04, indicating that overall the second cohort had slightly larger active-placebo-difference. Overall, on average there were minimal differences in effect size between the first and the second cohorts, and in 30 of 39 trials interim results were a good estimate of the results on the 2nd cohort. In AD trials first and second cohort results were more similar when the proportion of patients per study centre and recruitment time of the two cohorts was similar. Results suggest that interim analyses in AD and AP studies may reliably serve to estimate ultimate effects and, at least in AD trials, are more accurate when the same sites are used to a similar extent and recruitment time of the two consequent cohorts is similar.

Abstract LB-279: Quantitative flux measurements of serum protein catabolism in PDAC and other KRAS-mutant cancers

Activating KRAS mutations are prevalent in human cancer and are associated with poor prognosis. Among these malignancies is pancreatic ductal adenocarcinoma (PDAC), which is universally KRAS-driven and almost universally lethal. PDAC tumors are extremely fibrotic and hypovascularized, limiting perfusion of nutrients into the tumor, and tumor cells exhibit an altered metabolic program to support survival and proliferation in this environment. One metabolic activity upregulated in these tumor cells is the uptake and catabolism of serum protein. This process yields a substantial alternative source of amino acids and can support the proliferation of cultured cells lacking free essential amino acids. However, existing methods for assaying the uptake and degradation of intact protein provide qualitative outputs, and as such, do not yield accurate estimates of flux from serum protein to amino acid monomers. Here, we present a method for quantitative measurement of the catabolic production of amino acids from serum protein in cultured cells. By culturing cells in medium containing fully 13C-labeled glucose and amino acids supplemented with unlabeled albumin, we distinguish amino acids taken up as monomers from the medium from serum protein-derived amino acids. Using a variant of classical metabolic flux analysis, we derive flux estimates for serum protein catabolism from measurements of amino acid abundance and isotopic labeling over time. Our method is highly sensitive (i.e. can estimate “baseline” serum protein catabolism in KRAS wild-type cell lines) and yields precise estimates of amino acid influx from serum protein for all proteinogenic amino acids. We have measured serum protein catabolism in a variety of cultured cell lines and find that protein catabolism yields amino acids in comparable amounts to conventional uptake in various pancreatic and non-pancreatic lines. This approach enables estimation of protein catabolic flux in any cell line and can be used to assay the effects of various genetic and pharmacological perturbations on serum protein catabolism with high sensitivity and while accounting for growth rate differences.

Citation Format: Michel Nofal, Kevin Zhang, Josh Rabinowitz. Quantitative flux measurements of serum protein catabolism in PDAC and other KRAS-mutant cancers. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-279. doi:10.1158/1538-7445.AM2015-LB-279

Steady-state metabolite concentrations reflect a balance between maximizing enzyme efficiency and minimizing total metabolite load

Steady-state metabolite concentrations in a microorganism typically span several orders of magnitude. The underlying principles governing these concentrations remain poorly understood. Here, we hypothesize that observed variation can be explained in terms of a compromise between factors that favor minimizing metabolite pool sizes (e.g. limited solvent capacity) and the need to effectively utilize existing enzymes. The latter requires adequate thermodynamic driving force in metabolic reactions so that forward flux substantially exceeds reverse flux. To test this hypothesis, we developed a method, metabolic tug-of-war (mTOW), which computes steady-state metabolite concentrations in microorganisms on a genome-scale. mTOW is shown to explain up to 55% of the observed variation in measured metabolite concentrations in E. coli and C. acetobutylicum across various growth media. Our approach, based strictly on first thermodynamic principles, is the first method that successfully predicts high-throughput metabolite concentration data in bacteria across conditions.

Trajectories and antecedents of treatment response over time in early-episode psychosis

BACKGROUND

Little is known about the extent of heterogeneity of symptomatology in treated early-onset psychosis. The current study aims to quantify the extent of heterogeneity in trajectories of treated symptom severity in early-episode psychosis and their antecedents.

METHODS

Data were from 491 persons with early-episode psychosis from a clinical trial of haloperidol and risperidone. Positive and Negative Syndrome Scale (PANSS) administrations were used to measure symptom severity trajectories for (a) rapid treatment response scores over 4 weeks and (b) medium-term course over 24 weeks. Baseline antecedents included sex, Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, diagnosis, age of onset, the Premorbid Adjustment Scale, and a cognitive test battery. Symptom severity trajectories were calculated with mixed mode latent class regression modeling from which groups were derived.

RESULTS

Five groups based on PANSS scores over time were identified. Over 4 weeks, 3 groups with varied baseline PANSS scores (54-105) did not surpass 30% PANSS improvement. Another group improved and then was stable (n = 76,15.3%), and another showed marked improvement (n = 94,18.9%). Logistic regression showed that membership in the best response trajectory was associated with not having a diagnosis of schizophrenia, good premorbid functioning, and higher cognitive functioning, whereas membership in the poor response trajectory was associated with earlier age of onset and poorer cognitive functioning.

CONCLUSION

Amelioration generally characterizes treated symptom severity. Age of onset, diagnosis, cognitive functioning, and premorbid functioning have prognostic value in predicting treatment response trajectories.

Validity of the premorbid adjustment scale

BACKGROUND

The aim of the current study was to test the predictive and concurrent validity of the Premorbid Adjustment Scale (PAS) by comparing it with another similar but more elaborate retrospective measure and with data collected during late adolescence.

METHODS

We compared PAS late adolescence scores (age 16-18 years) of 91 males with schizophrenia or schizoaffective disorder with data on behavior collected in adolescence, before the first psychotic episode as part of standardized Draft Board screening, and with the same measure readministered during adulthood and modified to collect the same data again retrospectively.

RESULTS

The correlation of the PAS social withdrawal and social relations items with the social behavior scale of the Draft Board were .76 and .80, respectively, for the concurrent ratings and .52 and .53, respectively, for the data collected at age 17 years. The correlation of the PAS school achievements and school adjustment items with the functioning in structured environments scale of the Draft Board were .71 and .72, respectively, for the concurrent ratings and .43 and .47, respectively, for the data collected at age 17 years.

CONCLUSIONS

Our results support the predictive and concurrent validity of the PAS and the validity of self-reported data on premorbid functioning in persons with schizophrenia.

Accuracy of self-reported premorbid functioning in schizophrenia

BACKGROUND

Information on premorbid functioning is often based on patients recalling their past. Premorbid functioning is relevant as it is associated with treatment response and other outcomes. The extent to which memory impairments of persons with schizophrenia may bias such reporting has not been investigated. The purpose of the current study was to assess the extent to which persons with schizophrenia might exhibit biased reporting relative to controls.

METHODS

Seventy males with schizophrenia or schizoaffective disorder and 51 males with no psychiatric symptoms participated in the study. Contemporaneous and retrospective reports from a behavioral functioning assessment conducted as part of the Israeli Draft Board were compared. This assessment routinely administered to all 17 years old males in the country assesses social functioning, individual autonomy, organizational ability, physical activity and functioning in structured environments. We compared the groups on the Draft Board behavioral measures at age 17 and at re-assessment. We also examined the relationship between symptom severity, neuropsychological performance and differences between age 17 and current behavioral assessment scores.

RESULTS

In a repeated measures MANCOVA of the five measures there was no overall significant difference in accuracy of reporting between persons with schizophrenia and those without. Both groups showed a slight tendency to glorify their past. Consistency of reporting was not significantly correlated with neuropsychological performance or levels of psychotic symptoms.

CONCLUSIONS

We found that when reporting on personal and social functioning during teen age years persons with schizophrenia report with the same level of consistency as persons without schizophrenia. This suggests that self-report of premorbid functioning of persons with schizophrenia can be trusted as being reasonably accurate.

Cognitive performance of male adolescents is lower than controls across psychiatric disorders: a population-based study

OBJECTIVE

Psychiatric patients, as well as humans or experimental animals with brain lesions, often concurrently manifest behavioral deviations and subtle cognitive impairments. This study tested the hypothesis that as a group, adolescents suffering from psychiatric disorders score worse on cognitive tests compared with controls.

METHOD

As part of the assessment for eligibility to serve in the military, the entire, unselected population of 16-17-year old male Israelis undergo cognitive testing and screening for psychopathology by the Draft Board. We retrieved the cognitive test scores of 19 075 adolescents who were assigned any psychiatric diagnosis, and compared them with the scores of 243 507 adolescents without psychiatric diagnoses.

RESULTS

Mean test scores of cases were significantly poorer then controls for all diagnostic groups, except for eating disorders. Effect sizes ranged from 0.3 to 1.6.

CONCLUSION

As group, adolescent males with psychiatric disorders manifest at least subtle impairments in cognitive functioning.