Examining the impact of structural uncertainty across ten type 2 diabetes models: Results from the 2022 Mount Hood Challenge.

OBJECTIVE: The Mount Hood Diabetes Challenge Network aimed to examine the impact of model structural uncertainty on the estimated cost-effectiveness of interventions for type 2 diabetes. METHODS: Ten independent modelling groups completed a blinded simulation exercise to estimate the cost-effectiveness of three interventions in two type 2 diabetes populations. Modelling groups were provided with a common baseline population, cost and utility values associated with different model health states, and instructions regarding time horizon and discounting. We collated the results to identify variation in predictions of net monetary benefit (NMB), and the drivers of those differences. RESULTS: Overall, modelling groups agreed which interventions had a positive NMB (i.e. were cost-effective), though estimates of NMB varied substantially- by up to £23,696 for one intervention. Variation was mainly driven through differences in risk equations for complications of diabetes and their implementation between models. The number of modelled health states was also a significant predictor of NMB. CONCLUSIONS: This exercise demonstrates that structural uncertainty between different health economic models impacts cost-effectiveness estimates. Whilst it is reassuring that a decision maker would likely reach similar conclusions on which interventions were cost-effective using most models, the range in numerical estimates generated across different models would nevertheless be important for price-setting negotiations with intervention developers. Minimising the impact of structural uncertainty on healthcare decision making therefore remains an important priority. Model registries, which record and compare the impact of structural assumptions, offer one potential avenue to improve confidence in the robustness of health economic modelling.

Update and nomenclature proposal for mammalian lysophospholipid acyltransferases, which create membrane phospholipid diversity.

The diversity of glycerophospholipid species in cellular membranes is immense and affects various biological functions. Glycerol-3-phosphate acyltransferases (GPATs) and lysophospholipid acyltransferases (LPLATs), in concert with phospholipase A1/2s enzymes, contribute to this diversity via selective esterification of fatty acyl chains at the sn-1 or sn-2 positions of membrane phospholipids. These enzymes are conserved across all kingdoms, and in mammals four GPATs of the 1-acylglycerol-3-phosphate O-acyltransferase (AGPAT) family and at least 14 LPLATs, either of the AGPAT or the membrane-bound O-acyltransferase (MBOAT) families, have been identified. Here we provide an overview of the biochemical and biological activities of these mammalian enzymes, including their predicted structures, involvements in human diseases, and essential physiological roles as revealed by gene-deficient mice. Recently, the nomenclature used to refer to these enzymes has generated some confusion due to the use of multiple names to refer to the same enzyme and instances of the same name being used to refer to completely different enzymes. Thus, this review proposes a more uniform LPLAT enzyme nomenclature, as well as providing an update of recent advances made in the study of LPLATs, continuing from our JBC mini review in 2009.

Long-term cost-effectiveness analysis of tirzepatide versus semaglutide 1.0 mg for the management of type 2 diabetes in the United States.

AIM: To evaluate the long-term cost-effectiveness of tirzepatide (5, 10 and 15 mg doses), a novel glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist, versus semaglutide 1.0 mg, an injectable glucagon-like peptide-1 receptor agonist, based on the results of the head-to-head SURPASS-2 trial, from a US healthcare payer perspective. MATERIALS AND METHODS: The PRIME Type 2 Diabetes Model was used to make projections of clinical and cost outcomes over a 50-year time horizon. Baseline cohort characteristics, treatment effects and adverse event rates were derived from the 40-week SURPASS-2 trial. Intensification to insulin therapy occurred when HbA1c reached 7.5%, in line with American Diabetes Association recommendations. Direct costs in 2021 US dollars (US$) and health state utilities were derived from published sources. Future costs and clinical benefits were discounted at 3% annually. RESULTS: All three doses of tirzepatide were associated with lower diabetes-related complication rates, improved life expectancy, improved quality-adjusted life expectancy and higher direct costs versus semaglutide. This resulted in incremental cost-effectiveness ratios of US$ 75 803, 58 908 and 48 785 per quality-adjusted life year gained for tirzepatide 5, 10 and 15 mg, respectively, versus semaglutide. Tirzepatide remained cost-effective versus semaglutide over a range of sensitivity analyses. CONCLUSIONS: Long-term projections based on the SURPASS-2 trial results indicate that 5, 10 and 15 mg doses of tirzepatide are likely to be cost-effective versus semaglutide 1.0 mg for the treatment of type 2 diabetes in the United States.

The burden of poor glycaemic control in people with newly diagnosed type 2 diabetes in Sweden: A health economic modelling analysis based on nationwide data.

AIM: To evaluate the economic and clinical burden associated with poor glycaemic control in Sweden, in people with type 2 diabetes (T2D) initiating first-line glucose-lowering therapy. MATERIALS AND METHODS: Population data were obtained from Swedish national registers. Immediate glycaemic control was compared with delays in achieving control of 1 and 3 years, with outcomes projected over 3, 10 and 50 years in the validated IQVIA CORE Diabetes Model. Glycaemic control was defined as glycated haemoglobin (HbA1c) targets of 52, 48 and 42 mmol/mol, as recommended in Swedish guidelines, according to age and disease duration. Costs (expressed in 2019 Swedish krona [SEK]) were accounted from a Swedish societal perspective. RESULTS: Immediate glycaemic control was associated with population-level cost savings of up to SEK 279 million and SEK 673 million versus delays of 1 and 3 years, respectively, as well as small population-level life expectancy benefits of up to 1305 and 2590 life years gained. Reduced levels of burden were a result of lower incidence and delayed time to onset of diabetes-related complications. CONCLUSIONS: Even in people with T2D initiating first-line glucose-lowering therapy, the economic burden of poor glycaemic control in Sweden is substantial, but could be reduced by early and effective treatment to achieve glycaemic targets.

Toxic Peripheral Neuropathies: Agents and Mechanisms.

Toxic peripheral neuropathies are an important form of acquired polyneuropathy produced by a variety of xenobiotics and different exposure scenarios. Delineating the mechanisms of neurotoxicants and determining the degenerative biological pathways triggered by peripheral neurotoxicants will facilitate the development of sensitive and specific biochemical-based methods for identifying neurotoxicants, designing therapeutic interventions, and developing structure-activity relationships for predicting potential neurotoxicants. This review presents an overview of the general concepts of toxic peripheral neuropathies with the goal of providing insight into why certain agents target the peripheral nervous system and produce their associated lesions. Experimental data and the main hypotheses for the mechanisms of selected agents that produce neuronopathies, axonopathies, or myelinopathies including covalent or noncovalent modifications, compromised energy or protein biosynthesis, and oxidative injury and disruption of ionic gradients across membranes are presented. The relevance of signaling between the main components of peripheral nerve, that is, glia, neuronal perikaryon, and axon, as a target for neurotoxicants and the contribution of active programmed degenerative pathways to the lesions observed in toxic peripheral neuropathies is also discussed.

Druggable Lysophospholipid Signaling Pathways.

Lysophosphatidic acid (LPA) has major roles as a bioactive signaling molecule, with multiple physiological and pathological roles being described in almost every major organ system. In this review we discuss LPA signaling pathways as emerging drug targets for multiple conditions relevant to human health and disease. LPA signals through the six G protein-coupled receptors LPA1-6, and several of these receptors along with the LPA-producing enzyme including autotaxin (ATX) are now established as therapeutic targets with potential to treat various human diseases as exemplified by several LPA signaling targeting compounds now in clinical trials for idiopathic pulmonary fibrosis and systemic sclerosis. Several crystal structures of LPA receptors and ATX have been solved, which will accelerate development of highly selective and effective LPA signaling targeting compounds. We also review additional bioactive lysophospholipid (LPL) signaling molecules including lysophosphatidylserine and lysophosphatidylinositol, which represent the next wave of LPL druggable targets. An emerging theme in bioactive LPL signaling is that where the ligand is produced and how it is delivered to the cognate receptor are critical determinants of the biological responses. We will also discuss how connecting the production and function of bioactive LPLs will identify new therapeutic strategies to effectively target LPL signaling pathways.

Biosynthetic Enzymes of Membrane Glycerophospholipid Diversity as Therapeutic Targets for Drug Development.

Biophysical properties of membranes are dependent on their glycerophospholipid compositions. Lysophospholipid acyltransferases (LPLATs) selectively incorporate fatty chains into lysophospholipids to affect the fatty acid composition of membrane glycerophospholipids. Lysophosphatidic acid acyltransferases (LPAATs) of the 1-acylglycerol-3-phosphate O-acyltransferase (AGPAT) family incorporate fatty chains into phosphatidic acid during the de novo glycerophospholipid synthesis in the Kennedy pathway. Other LPLATs of both the AGPAT and the membrane bound O-acyltransferase (MBOAT) families further modify the fatty chain compositions of membrane glycerophospholipids in the remodeling pathway known as the Lands' cycle. The LPLATs functioning in these pathways possess unique characteristics in terms of their biochemical activities, regulation of expressions, and functions in various biological contexts. Essential physiological functions for LPLATs have been revealed in studies using gene-deficient mice, and important roles for several enzymes are also indicated in human diseases where their mutation or dysregulation causes or contributes to the pathological condition. Now several LPLATs are emerging as attractive therapeutic targets, and further understanding of the mechanisms underlying their physiological and pathological roles will aid in the development of novel therapies to treat several diseases that involve altered glycerophospholipid metabolism.

Cost-effectiveness of bevacizumab plus paclitaxel versus paclitaxel for the first-line treatment of HER2-negative metastatic breast cancer in specialist oncology centers in France.

BACKGROUND: Evidence from clinical trials suggests that the addition of bevacizumab to chemotherapy in the first-line treatment of patients with HER2-negative metastatic breast cancer improves progression-free survival (PFS) but not overall survival (OS). However, a retrospective analysis of real-world data from the French Comprehensive Cancer Centers (FCCC) through the Epidemiological Strategy and Medical Economics (ESME) Research Program, suggested that in this setting, the addition of bevacizumab may confer a significant benefit in terms of both PFS and OS. A cost-effectiveness analysis was performed to determine the cost-effectiveness of bevacizumab plus paclitaxel versus paclitaxel alone in the first-line treatment of HER2-negative metastatic breast cancer at specialist oncology centers in France. METHODS: The analysis was performed using a three-state Markov model and clinical input data from N = 3426 HER2-negative metastatic breast cancer patients treated with bevacizumab plus paclitaxel or paclitaxel alone. The analysis was performed from a third party payer perspective over a 10-year time horizon; future costs and clinical outcomes were discounted at 4% per annum. RESULTS: In the overall population, the addition of bevacizumab to paclitaxel led to incremental gain of 0.72 life years and 0.48 quality-adjusted life years (QALYs) relative to paclitaxel alone. The incremental lifetime cost of the addition of bevacizumab was EUR 27,390, resulting in an incremental cost-effectiveness ratio (ICER) of EUR 56,721 per QALY gained for bevacizumab plus paclitaxel versus paclitaxel alone. In a subgroup of triple negative patients the ICER was EUR 66,874 per QALY gained. CONCLUSIONS: The analysis indicated that the combination of bevacizumab plus paclitaxel is likely to be cost-effective compared with paclitaxel alone for the first-line treatment of HER2-negative metastatic breast cancer in specialized oncology centers in France.

Pyrrole adducts in globin and plasma of workers exposed to hexane.

OBJECTIVES: Urinary excretion of 2,5-hexanedione is currently used to estimate the exposure levels of hexane occurring to an individual during the previous work shift. However, because hexane exposures and urinary 2,5-hexanedione levels can vary considerably from day to day, and subchronic to chronic exposures to hexane are required to produce neuropathy, this biomarker may not accurately reflect the risk of an individual for developing hexane neuropathy. This investigation examines the potential of hexane-derived pyrrole adducts produced on globin and plasma proteins as markers for integrating cumulative exposures. Because the pyrrole markers incorporate bioactivation of hexane to 2,5-hexandione and the initial step of protein adduction involved in hexane-induced neuropathy, they potentially can serve as biomarkers of effect through reflecting pathogenetic events within the nervous system. Additionally, pyrrole formation is an irreversible reaction suggesting that hexane-derived protein pyrroles can be used to assess cumulative exposures to provide a better characterization of individual susceptibilities. METHODS: To examine the utility of the proposed markers, blood samples were obtained from eleven workers who used hexane for granulating metal powders in a slurry to produce metal machining die tools and four non-exposed volunteers. Globin and plasma were isolated, and the proteins were digested using pepsin, reacted with Ehrlich's reagent and the level of pyrrole adducts were determined by absorbance at 530 nm. To determine the dose-response curve and dynamic range of the assay, erythrocytes were incubated with a range of 2,5-hexanedione concentrations and the net absorbance at 530 nm of isolated globin was measured. RESULTS: Pyrrole was detected in both the globin and plasma samples of the workers exposed to hexane and the levels of pyrroles in plasma were positively correlated with the levels of pyrroles in globin for most of the workers. CONCLUSIONS: This investigation demonstrates that detectable levels of hexane-derived protein pyrrole adducts are produced on peripheral proteins following occupational exposures to hexane and supports the utility of measuring pyrroles for integrating cumulative exposures to hexane.

LPAAT3 incorporates docosahexaenoic acid into skeletal muscle cell membranes and is upregulated by PPARδ activation.

Adaption of skeletal muscle to endurance exercise includes PPARδ- and AMP-activated protein kinase (AMPK)/PPARγ coactivator 1α-mediated transcriptional responses that result in increased oxidative capacity and conversion of glycolytic to more oxidative fiber types. These changes are associated with whole-body metabolic alterations including improved glucose handling and resistance to obesity. Increased DHA (22:6n-3) content in phosphatidylcholine (PC) and phosphatidylethanolamine (PE) is also reported in endurance exercise-trained glycolytic muscle; however, the DHA-metabolizing enzymes involved and the biological significance of the enhanced DHA content are unknown. In the present study, we identified lysophosphatidic acid acyltransferase (LPAAT)3 as an enzyme that was upregulated in myoblasts during in vitro differentiation and selectively incorporated DHA into PC and PE. LPAAT3 expression was increased by pharmacological activators of PPARδ or AMPK, and combination treatment led to further increased LPAAT3 expression and enhanced incorporation of DHA into PC and PE. Our results indicate that LPAAT3 was upregulated by exercise-induced signaling pathways and suggest that LPAAT3 may also contribute to the enhanced phospholipid-DHA content of endurance-trained muscles. Identification of DHA-metabolizing enzymes in the skeletal muscle will help to elucidate broad metabolic effects of DHA.

Computer Modeling of Diabetes and Its Transparency: A Report on the Eighth Mount Hood Challenge.

OBJECTIVES: The Eighth Mount Hood Challenge (held in St. Gallen, Switzerland, in September 2016) evaluated the transparency of model input documentation from two published health economics studies and developed guidelines for improving transparency in the reporting of input data underlying model-based economic analyses in diabetes. METHODS: Participating modeling groups were asked to reproduce the results of two published studies using the input data described in those articles. Gaps in input data were filled with assumptions reported by the modeling groups. Goodness of fit between the results reported in the target studies and the groups' replicated outputs was evaluated using the slope of linear regression line and the coefficient of determination (R2). After a general discussion of the results, a diabetes-specific checklist for the transparency of model input was developed. RESULTS: Seven groups participated in the transparency challenge. The reporting of key model input parameters in the two studies, including the baseline characteristics of simulated patients, treatment effect and treatment intensification threshold assumptions, treatment effect evolution, prediction of complications and costs data, was inadequately transparent (and often missing altogether). Not surprisingly, goodness of fit was better for the study that reported its input data with more transparency. To improve the transparency in diabetes modeling, the Diabetes Modeling Input Checklist listing the minimal input data required for reproducibility in most diabetes modeling applications was developed. CONCLUSIONS: Transparency of diabetes model inputs is important to the reproducibility and credibility of simulation results. In the Eighth Mount Hood Challenge, the Diabetes Modeling Input Checklist was developed with the goal of improving the transparency of input data reporting and reproducibility of diabetes simulation model results.

Toxicologic Pathology of the Peripheral Nervous System (PNS): Overview, Challenges, and Current Practices.

Peripheral nervous system (PNS) toxicity is a frequent adverse effect encountered in patients treated with certain therapeutics (e.g., antiretroviral drugs, cancer chemotherapeutics), in occupational workers exposed to industrial chemicals (e.g., solvents), or during accidental exposures to household chemicals and/or environmental agents (e.g., pesticides). However, the literature and expertise needed for the effective design, conduct, analysis, and reporting of safety studies to identify and define PNS toxicity are hard to find. This half-day course familiarized participants with basic PNS biology; causes and mechanisms of PNS pathology; classic methods and current best practice recommendations for PNS sampling, preparation, and evaluation; and examples of commonly observed lesions and artifacts. Three concluding case presentations synthesized information from the prior technical lectures by presenting real-world examples of lesions caused by drugs and chemicals to demonstrate how PNS toxicity may be addressed in evaluating product safety during nonclinical studies. Topics emphasized comparative and correlative data among animal species used in toxicity studies and clinical evaluation in humans in order to facilitate the translation of animal data into human risk assessment with respect to PNS toxicologic pathology.

Evaluation of the long-term cost-effectiveness of liraglutide vs lixisenatide for treatment of type 2 diabetes mellitus in the UK setting.

AIMS: To compare the cost-effectiveness of 2 glucagon-like peptide-1 (GLP-1) receptor agonists, liraglutide 1.8 mg and lixisenatide 20 µg, in the UK setting based on the LIRA-LIXI trial (NCT01973231). MATERIALS AND METHODS: Projections of costs (in 2015 pounds sterling [£]) and clinical outcomes were made over patient lifetimes using the IMS CORE Diabetes Model (IMS Health, Basel, Switzerland). The baseline cohort and treatment effects applied after initiation of GLP-1 receptor agonists were taken from the LIRA-LIXI trial. Future costs and clinical benefits were discounted at 3.5% annually. RESULTS: Liraglutide 1.8 mg was associated with improved discounted quality-adjusted life expectancy (8.87 vs 8.76 quality-adjusted life years [QALYs]) vs lixisenatide 20 µg. A greater reduction in glycated haemoglobin with liraglutide 1.8 mg led to fewer diabetes-related complications and delayed their time of onset. Liraglutide 1.8 mg was associated with increased total costs (£37 153 vs £36 174), driven by higher acquisition costs, but this was partially offset by savings from diabetes-related complications avoided (£26 969 vs £27 912). Liraglutide 1.8 mg was associated with an incremental cost-effectiveness ratio of £8901 per QALY gained vs lixisenatide 20 µg. CONCLUSIONS: Long-term projections suggest that treatment of patients with type 2 diabetes with liraglutide 1.8 mg is likely to be considered highly cost-effective compared with lixisenatide 20 µg treatment in the UK setting.

Projected long-term outcomes in patients with type 1 diabetes treated with fast-acting insulin aspart vs conventional insulin aspart in the UK setting.

AIM: To assess the impact of faster aspart vs insulin aspart on long-term clinical outcomes and costs for patients with type 1 diabetes mellitus (T1DM) in the UK setting. METHODS: The QuintilesIMS CORE Diabetes Model was used to project clinical outcomes and costs over patient lifetimes in a cohort with data on baseline characteristics from the "onset 1" trial. Treatment effects were taken from the 26-week main phase of the onset 1 trial, with costs and utilities based on literature review. Future costs and clinical benefits were discounted at 3.5% annually. RESULTS: Projections indicated that faster aspart was associated with improved discounted quality-adjusted life expectancy (by 0.13 quality-adjusted life-years) vs insulin aspart. Improved clinical outcomes resulted from fewer diabetes-related complications and a delayed time to their onset with faster aspart. Faster aspart was found to be associated with reduced costs vs insulin aspart (cost savings of £1715), resulting from diabetes-related complications avoided and reduced treatment costs. CONCLUSIONS: Faster aspart was associated with improved clinical outcomes and cost savings vs insulin aspart for patients with T1DM in the UK setting.

The Prime Diabetes Model: Novel Methods for Estimating Long-Term Clinical and Cost Outcomes in Type 1 Diabetes Mellitus.

BACKGROUND: Recent publications describing long-term follow-up from landmark trials and diabetes registries represent an opportunity to revisit modeling options in type 1 diabetes mellitus (T1DM). OBJECTIVES: To develop a new product-independent model capable of predicting long-term clinical and cost outcomes. METHODS: After a systematic literature review to identify clinical trial and registry data, a model was developed (the PRIME Diabetes Model) to simulate T1DM progression and complication onset. The model runs as a patient-level simulation, making use of covariance matrices for cohort generation and risk factor progression, and simulating myocardial infarction, stroke, angina, heart failure, nephropathy, retinopathy, macular edema, neuropathy, amputation, hypoglycemia, ketoacidosis, mortality, and risk factor evolution. Several approaches novel to T1DM modeling were used, including patient characteristics and risk factor covariance, a glycated hemoglobin progression model derived from patient-level data, and model averaging approaches to evaluate complication risk. RESULTS: Validation analyses comparing modeled outcomes with published studies demonstrated that the PRIME Diabetes Model projects long-term patient outcomes consistent with those reported for a number of long-term studies. Macrovascular end points were reliably reproduced across five different populations and microvascular complication risk was accurately predicted on the basis of comparisons with landmark studies and published registry data. CONCLUSIONS: The PRIME Diabetes Model is product-independent, available online, and has been developed in line with good practice guidelines. Validation has indicated that outcomes from long-term studies can be reliably reproduced. The model offers new approaches to long-standing challenges in diabetes modeling and may become a valuable tool for informing health care policy.

The microstructural correlates of T1 in white matter.

PURPOSE: Several studies have shown strong correlations between myelin content and T1 within the brain, and have even suggested that T1 can be used to estimate myelin content. However, other micro-anatomical features such as compartment size are known to affect longitudinal relaxation rates, similar to compartment size effects in porous media. METHODS: T1 measurements were compared with measured or otherwise published axon size measurements in white matter tracts of the rat spinal cord, rat brain, and human brain. RESULTS: In both ex vivo and in vivo studies, correlations were present between the relaxation rate 1/T1 and axon size across regions of rat spinal cord with nearly equal myelin content. CONCLUSION: While myelination is likely the dominant determinant of T1 in white matter, variations in white matter microstructure, independent of myelin volume fraction, may also be reflected in T1 differences between regions or subjects.

A role for the p75 neurotrophin receptor in axonal degeneration and apoptosis induced by oxidative stress.

The p75 neurotrophin receptor (p75(NTR)) mediates the death of specific populations of neurons during the development of the nervous system or after cellular injury. The receptor has also been implicated as a contributor to neurodegeneration caused by numerous pathological conditions. Because many of these conditions are associated with increases in reactive oxygen species, we investigated whether p75(NTR) has a role in neurodegeneration in response to oxidative stress. Here we demonstrate that p75(NTR) signaling is activated by 4-hydroxynonenal (HNE), a lipid peroxidation product generated naturally during oxidative stress. Exposure of sympathetic neurons to HNE resulted in neurite degeneration and apoptosis. However, these effects were reduced markedly in neurons from p75(NTR-/-) mice. The neurodegenerative effects of HNE were not associated with production of neurotrophins and were unaffected by pretreatment with a receptor-blocking antibody, suggesting that oxidative stress activates p75(NTR) via a ligand-independent mechanism. Previous studies have established that proteolysis of p75(NTR) by the metalloprotease TNFα-converting enzyme and γ-secretase is necessary for p75(NTR)-mediated apoptotic signaling. Exposure of sympathetic neurons to HNE resulted in metalloprotease- and γ-secretase-dependent cleavage of p75(NTR). Pharmacological blockade of p75(NTR) proteolysis protected sympathetic neurons from HNE-induced neurite degeneration and apoptosis, suggesting that cleavage of p75(NTR) is necessary for oxidant-induced neurodegeneration. In vivo, p75(NTR-/-) mice exhibited resistance to axonal degeneration associated with oxidative injury following administration of the neurotoxin 6-hydroxydopamine. Together, these data suggest a novel mechanism linking oxidative stress to ligand-independent cleavage of p75(NTR), resulting in axonal fragmentation and neuronal death.

Ziram and sodium N,N-dimethyldithiocarbamate inhibit ubiquitin activation through intracellular metal transport and increased oxidative stress in HEK293 cells.

Ubiquitin activating enzyme E1 plays a pivotal role in ubiquitin based protein signaling through regulating the initiating step of the cascade. Previous studies demonstrated that E1 is inhibited by covalent modification of reactive cysteines contained within the ubiquitin-binding groove and by conditions that increase oxidative stress and deplete cellular antioxidants. In this study, we determined the relative contribution of covalent adduction and oxidative stress to E1 inhibition produced by ziram and sodium N,N-dimethyldithiocarbamate (DMDC) in HEK293 cells. Although no dithiocarbamate-derived E1 adducts were identified on E1 using shotgun LC/MS/MS for either ziram or DMDC, both dithiocarbamates significantly decreased E1 activity, with ziram demonstrating greater potency. Ziram increased intracellular levels of zinc and copper, DMDC increased intracellular levels of only copper, and both dithiocarbamates enhanced oxidative injury evidenced by elevated levels of protein carbonyls and expression of heme oxygenase-1. To assess the contribution of intracellular copper transport to E1 inhibition, coincubations were performed with the copper chelator triethylenetetramine hydrochloride (TET). TET significantly protected E1 activity for both of the dithiocarbamates and decreased the associated oxidative injury in HEK293 cells as well as prevented dithiocarbamate-mediated lipid peroxidation assayed using an ethyl aracidonate micelle system. Because TET did not completely ameliorate intracellular transport of copper or zinc for ziram, TET apparently maintained E1 activity through its ability to diminish dithiocarbamate-mediated oxidative stress. Experiments to determine the relative contribution of elevated intracellular zinc and copper were performed using a metal free incubation system and showed that increases in either metal were sufficient to inhibit E1. To evaluate the utility of the HEK293 in vitro system for screening environmental agents, a series of additional pesticides and metals was assayed, and eight agents that produced a significant decrease and five that produced a significant increase in activated E1 were identified. These studies suggest that E1 is a sensitive redox sensor that can be modulated by exposure to environmental agents and can regulate downstream cellular processes.

Achieving sustained virologic response in hepatitis C: a systematic review of the clinical, economic and quality of life benefits.

BACKGROUND: The goal of chronic hepatitis C treatment is to remove the virus to avoid progression of HCV-related disease. Sustained virologic response (SVR) is the most widely used efficacy endpoint in clinical studies of hepatitis C, and represents the eradication of HCV from the body. The aim of the current review was to examine the long-term clinical, economic and quality of life benefits associated with achieving SVR. METHODS: A systematic literature review was performed using the PubMed, EMBASE and Cochrane library databases to identify articles examining the clinical, economic and quality of life benefits associated with SVR, published in English language from 2002-2013. For inclusion studies were required to enroll ≥100 patients and to report clinical endpoints including hepatocellular carcinoma, overall- or liver-related mortality, or progression of disease/complications (e.g. portal hypertension, esophageal varices). Review of economic studies on cost/cost-effectiveness of achieving SVR were focused on studies assessing boceprevir/telaprevir plus pegIFN and ribavirin as this represents the current standard of care in several jurisdictions worldwide. Quality of life evidence was required to use validated quality of life instruments and provide a quantitative analysis of the impact of SVR versus no treatment or treatment failure. RESULTS: SVR is durable with late relapse rates over 4-5 year periods being in the range of 1-2%. Patients who achieve SVR frequently demonstrate some regression of fibrosis/cirrhosis and have a substantially reduced risk for hepatocellular carcinoma (relative risk [RR] 0.1-0.25), liver-related mortality (RR 0.03-0.2) and overall mortality (RR 0.1-0.3) in comparison with no treatment or treatment failure. In the 5 years post-treatment, medical costs for patients achieving SVR are 13-fold lower than patients not achieving SVR. Patients who achieve SVR also have health state utility values that are 0.05 to 0.31 higher than non-responders to treatment. CONCLUSIONS: SVR represents the fundamental goal of antiviral treatment for patients infected with chronic HCV, so as to reduce risk of liver disease progression. Achievement of SVR has implications beyond those of clearing viral infection; it is associated with improved long-term clinical outcomes, economic benefits and improved health-related quality of life.

Mitigation of radiation injury by selective stimulation of the LPA(2) receptor.

Due to its antiapoptotic action, derivatives of the lipid mediator lysophosphatidic acid (LPA) provide potential therapeutic utility in diseases associated with programmed cell death. Apoptosis is one of the major pathophysiological processes elicited by radiation injury to the organism. Consequently, therapeutic explorations applying compounds that mimic the antiapoptotic action of LPA have begun. Here we present a brief account of our decade-long drug discovery effort aimed at developing LPA mimics with a special focus on specific agonists of the LPA(2) receptor subtype, which was found to be highly effective in protecting cells from apoptosis. We describe new evidence that 2-((3-(1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)propyl)thio)benzoic acid (GRI977143), a prototypic nonlipid agonist specific to the LPA(2) receptor subtype, rescues apoptotically condemned cells in vitro and in vivo from injury caused by high-dose γ-irradiation. GRI977143 shows the features of a radiomitigator because it is effective in rescuing the lives of mice from deadly levels of radiation when administered 24h after radiation exposure. Our findings suggest that by specifically activating LPA(2) receptors GRI977143 activates the ERK1/2 prosurvival pathway, effectively reduces Bax translocation to the mitochondrion, attenuates the activation of initiator and effector caspases, reduces DNA fragmentation, and inhibits PARP-1 cleavage associated with γ-irradiation-induced apoptosis. GRI977143 also inhibits bystander apoptosis elicited by soluble proapoptotic mediators produced by irradiated cells. Thus, GRI977143 can serve as a prototype scaffold for lead optimization paving the way to more potent analogs amenable for therapeutic exploration. This article is part of a Special Issue entitled Advances in Lysophospholipid Research.