FAAH levels and its genetic polymorphism association with susceptibility to methamphetamine dependence.

The fatty acid amide hydrolase (FAAH) gene was involved in the modulation of reward and addiction pathophysiology of illicit drugs abuse, and its polymorphisms might be associated with risk of methamphetamine (METH) dependence. This study aimed to investigate the FAAH mRNA levels in peripheral blood mononuclear cells and plasma protein levels and to analyze the 385C/A polymorphism (rs324420) between METH-dependent patients and controls. The levels of FAAH mRNA in METH dependence were significantly lower than in controls (P < 0.001), however, its plasma protein underwent a significant ∼2-fold increase (P < 0.001). The A allele of the 385C/A polymorphism significantly increased the METH dependence risk (P < 0.001, odds ratio [OR] = 1.646, 95% confidence interval [CI] = 1.332-2.034). The carried A genotypes (AA, AC, and AA/AC) of 385C/A polymorphism also increased METH-dependence risks under a different genetic model (AA vs. CC: P = 0.017, OR = 2.454, 95%CI = 1.171-2.143; AC vs. CC: P < 0.001, OR = 1.818, 95%CI = 1.404-2.353; AC/AA vs. CC: P < 0.001, OR = 1.858, 95%CI = 1.444-2.319). The similar results were obtained after adjusting for age and sex. Unfortunately, we failed to find that any genotype of 385C/A polymorphism affected the mRNA or plasma protein levels in controls, respectively (P > 0.05). These data indicate that the FAAH may play an important role in the pathophysiological process of METH dependence, and the 385C/A polymorphism may be associated with METH dependence susceptibility in a Chinese Han population.

Characterization of Parkinson's disease using blood-based biomarkers: A multicohort proteomic analysis.

BACKGROUND: Parkinson's disease (PD) is a progressive neurodegenerative disease affecting about 5 million people worldwide with no disease-modifying therapies. We sought blood-based biomarkers in order to provide molecular characterization of individuals with PD for diagnostic confirmation and prediction of progression. METHODS AND FINDINGS: In 141 plasma samples (96 PD, 45 neurologically normal control [NC] individuals; 45.4% female, mean age 70.0 years) from a longitudinally followed Discovery Cohort based at the University of Pennsylvania (UPenn), we measured levels of 1,129 proteins using an aptamer-based platform. We modeled protein plasma concentration (log10 of relative fluorescence units [RFUs]) as the effect of treatment group (PD versus NC), age at plasma collection, sex, and the levodopa equivalent daily dose (LEDD), deriving first-pass candidate protein biomarkers based on p-value for PD versus NC. These candidate proteins were then ranked by Stability Selection. We confirmed findings from our Discovery Cohort in a Replication Cohort of 317 individuals (215 PD, 102 NC; 47.9% female, mean age 66.7 years) from the multisite, longitudinally followed National Institute of Neurological Disorders and Stroke Parkinson's Disease Biomarker Program (PDBP) Cohort. Analytical approach in the Replication Cohort mirrored the approach in the Discovery Cohort: each protein plasma concentration (log10 of RFU) was modeled as the effect of group (PD versus NC), age at plasma collection, sex, clinical site, and batch. Of the top 10 proteins from the Discovery Cohort ranked by Stability Selection, four associations were replicated in the Replication Cohort. These blood-based biomarkers were bone sialoprotein (BSP, Discovery false discovery rate [FDR]-corrected p = 2.82 × 10-2, Replication FDR-corrected p = 1.03 × 10-4), osteomodulin (OMD, Discovery FDR-corrected p = 2.14 × 10-2, Replication FDR-corrected p = 9.14 × 10-5), aminoacylase-1 (ACY1, Discovery FDR-corrected p = 1.86 × 10-3, Replication FDR-corrected p = 2.18 × 10-2), and growth hormone receptor (GHR, Discovery FDR-corrected p = 3.49 × 10-4, Replication FDR-corrected p = 2.97 × 10-3). Measures of these proteins were not significantly affected by differences in sample handling, and they did not change comparing plasma samples from 10 PD participants sampled both on versus off dopaminergic medication. Plasma measures of OMD, ACY1, and GHR differed in PD versus NC but did not differ between individuals with amyotrophic lateral sclerosis (ALS, n = 59) versus NC. In the Discovery Cohort, individuals with baseline levels of GHR and ACY1 in the lowest tertile were more likely to progress to mild cognitive impairment (MCI) or dementia in Cox proportional hazards analyses adjusting for age, sex, and disease duration (hazard ratio [HR] 2.27 [95% CI 1.04-5.0, p = 0.04] for GHR, and HR 3.0 [95% CI 1.24-7.0, p = 0.014] for ACY1). GHR's association with cognitive decline was confirmed in the Replication Cohort (HR 3.6 [95% CI 1.20-11.1, p = 0.02]). The main limitations of this study were its reliance on the aptamer-based platform for protein measurement and limited follow-up time available for some cohorts. CONCLUSIONS: In this study, we found that the blood-based biomarkers BSP, OMD, ACY1, and GHR robustly associated with PD across multiple clinical sites. Our findings suggest that biomarkers based on a peripheral blood sample may be developed for both disease characterization and prediction of future disease progression in PD.

Microdeletion in a FAAH pseudogene identified in a patient with high anandamide concentrations and pain insensitivity.

The study of rare families with inherited pain insensitivity can identify new human-validated analgesic drug targets. Here, a 66-yr-old female presented with nil requirement for postoperative analgesia after a normally painful orthopaedic hand surgery (trapeziectomy). Further investigations revealed a lifelong history of painless injuries, such as frequent cuts and burns, which were observed to heal quickly. We report the causative mutations for this new pain insensitivity disorder: the co-inheritance of (i) a microdeletion in dorsal root ganglia and brain-expressed pseudogene, FAAH-OUT, which we cloned from the fatty-acid amide hydrolase (FAAH) chromosomal region; and (ii) a common functional single-nucleotide polymorphism in FAAH conferring reduced expression and activity. Circulating concentrations of anandamide and related fatty-acid amides (palmitoylethanolamide and oleoylethanolamine) that are all normally degraded by FAAH were significantly elevated in peripheral blood compared with normal control carriers of the hypomorphic single-nucleotide polymorphism. The genetic findings and elevated circulating fatty-acid amides are consistent with a phenotype resulting from enhanced endocannabinoid signalling and a loss of function of FAAH. Our results highlight previously unknown complexity at the FAAH genomic locus involving the expression of FAAH-OUT, a novel pseudogene and long non-coding RNA. These data suggest new routes to develop FAAH-based analgesia by targeting of FAAH-OUT, which could significantly improve the treatment of postoperative pain and potentially chronic pain and anxiety disorders.

Electrochemical Molecular Switch for the Selective Profiling of Cysteine in Live Cells and Whole Blood and for the Quantification of Aminoacylase-1.

A first-of-a-kind latent electrochemical redox probe, ferrocene carbamate phenyl acrylate (FCPA), was developed for the selective detection of cysteine (Cys) and aminoacylase (ACY-1). The electrochemical signal generated by this probe was shown to be highly specific to Cys and insensitive to other amino acids and biological redox reactants. The FCPA-incorporated electrochemical sensor exhibited a broad dynamic range of 0.25-100 µM toward Cys. This probe also proficiently monitored the ACY-1-catalyzed biochemical transformation of N-acetylcysteine (NAC) into Cys, and this proficiency was used to develop an electrochemical assay for quantifying active ACY-1, which it did so in a dynamic range of 10-200 pM (0.1-2 mU/cm3) with a detection limit of 1 pM (0.01 mU/cm3). Furthermore, the probe was utilized in real-time tracking and quantification of cellular Cys production, specifically in Escherichia coli W3110, along with a whole blood assay to determine levels of Cys and spiked ACY-1 in blood with a reliable analytical performance.

Evidence for a protective role for the rs805305 single nucleotide polymorphism of dimethylarginine dimethylaminohydrolase 2 (DDAH2) in septic shock through the regulation of DDAH activity.

BACKGROUND: Dimethylarginine dimethylaminohydrolase 2 (DDAH2) regulates the synthesis of nitric oxide (NO) through the metabolism of the endogenous inhibitor of nitric oxide synthase, asymmetric dimethylarginine (ADMA). Pilot studies have associated the rs805305 SNP of DDAH2 with ADMA concentrations in sepsis. This study explored the impact of the rs805305 polymorphism on DDAH activity and outcome in septic shock. METHODS: We undertook a secondary analysis of data and samples collected during the Vasopressin versus noradrenaline as initial therapy in septic shock (VANISH) trial. Plasma and DNA samples isolated from 286 patients recruited into the VANISH trial were analysed. Concentrations of L-Arginine and the methylarginines ADMA and symmetric dimethylarginine (SDMA) were determined from plasma samples. Whole blood and buffy-coat samples were genotyped for polymorphisms of DDAH2. Clinical data collected during the study were used to explore the relationship between circulating methylarginines, genotype and outcome. RESULTS: Peak ADMA concentration over the study period was associated with a hazard ratio for death at 28 days of 3.3 (95% CI 2.0-5.4), p < 0.001. Reduced DDAH activity measured by an elevated ADMA:SDMA ratio was associated with a reduced risk of death in septic shock (p = 0.03). The rs805305 polymorphism of DDAH2 was associated with reduced DDAH activity (p = 0.004) and 28-day mortality (p = 0.02). Mean SOFA score and shock duration were also reduced in the less common G:G genotype compared to heterozygotes and C:C genotype patients (p = 0.04 and p = 0.02, respectively). CONCLUSIONS: Plasma ADMA is a biomarker of outcome in septic shock, and reduced DDAH activity is associated with a protective effect. The polymorphism rs805305 SNP is associated with reduced mortality, which is potentially mediated by reduced DDAH2 activity. TRIAL REGISTRATION: ISRCTN Registry, ISRCTN20769191 . Registered on 20 September 2012.

Ratiometric Fluorescent Probe for Imaging of Pantetheinase in Living Cells.

Pantetheinase, which catalyzes the cleavage of pantetheine to pantothenic acid (vitamin B5) and cysteamine, is involved in the regulation of oxidative stress, pantothenate recycling and cell migration. However, further elucidating the cellular function of this enzyme is largely limited by the lack of a suitable fluorescence imaging probe. By conjugating pantothenic acid with cresyl violet, herein we develop a new fluorescence probe CV-PA for the assay of pantetheinase. The probe not only possesses long analytical wavelengths but also displays linear ratiometric (I628/582 nm) fluorescence response to pantetheinase in the range of 5-400 ng/mL with a detection limit of 4.7 ng/mL. This probe has been used to evaluate the efficiency of different inhibitors and quantitatively detect pantetheinase in serum samples, revealing that pantetheinase in fetal bovine serum and new born calf serum is much higher than that in normal human serum. Notably, with the probe the ratiometric imaging and in situ quantitative comparison of pantetheinase in different living cells (LO2 and HK-2) have been achieved for the first time. It is found that the level of pantetheinase in LO2 cells is much larger than that in HK-2 cells, as further validated by Western blot analysis. The proposed probe may be useful to better understand the specific function of pantetheinase in the pantetheinase-related pathophysiological processes.

Plasmodium Infection Is Associated with Impaired Hepatic Dimethylarginine Dimethylaminohydrolase Activity and Disruption of Nitric Oxide Synthase Inhibitor/Substrate Homeostasis.

Inhibition of nitric oxide (NO) signaling may contribute to pathological activation of the vascular endothelium during severe malaria infection. Dimethylarginine dimethylaminohydrolase (DDAH) regulates endothelial NO synthesis by maintaining homeostasis between asymmetric dimethylarginine (ADMA), an endogenous NO synthase (NOS) inhibitor, and arginine, the NOS substrate. We carried out a community-based case-control study of Gambian children to determine whether ADMA and arginine homeostasis is disrupted during severe or uncomplicated malaria infections. Circulating plasma levels of ADMA and arginine were determined at initial presentation and 28 days later. Plasma ADMA/arginine ratios were elevated in children with acute severe malaria compared to 28-day follow-up values and compared to children with uncomplicated malaria or healthy children (p<0.0001 for each comparison). To test the hypothesis that DDAH1 is inactivated during Plasmodium infection, we examined DDAH1 in a mouse model of severe malaria. Plasmodium berghei ANKA infection inactivated hepatic DDAH1 via a post-transcriptional mechanism as evidenced by stable mRNA transcript number, decreased DDAH1 protein concentration, decreased enzyme activity, elevated tissue ADMA, elevated ADMA/arginine ratio in plasma, and decreased whole blood nitrite concentration. Loss of hepatic DDAH1 activity and disruption of ADMA/arginine homeostasis may contribute to severe malaria pathogenesis by inhibiting NO synthesis.

Markers of nitric oxide are associated with sepsis severity: an observational study.

BACKGROUND: Nitric oxide (NO) regulates processes involved in sepsis progression, including vascular function and pathogen defense. Direct NO measurement in patients is unfeasible because of its short half-life. Surrogate markers for NO bioavailability are substrates of NO generating synthase (NOS): L-arginine (lArg) and homoarginine (hArg) together with the inhibitory competitive substrate asymmetric dimethylarginine (ADMA). In immune cells ADMA is cleaved by dimethylarginine-dimethylaminohydrolase-2 (DDAH2). The aim of this study was to investigate whether concentrations of surrogate markers for NO bioavailability are associated with sepsis severity. METHOD: This single-center, prospective study involved 25 controls and 100 patients with surgical trauma (n = 20), sepsis (n = 63), or septic shock (n = 17) according to the Sepsis-3 definition. Plasma lArg, hArg, and ADMA concentrations were measured by mass spectrometry and peripheral blood mononuclear cells (PBMCs) were analyzed for DDAH2 expression. RESULTS: lArg concentrations did not differ between groups. Median (IQR) hArg concentrations were significantly lower in patient groups than controls, being 1.89 (1.30-2.29) µmol/L (P < 0.01), with the greatest difference in the septic shock group, being 0.74 (0.36-1.44) µmol/L. In contrast median ADMA concentrations were significantly higher in patient groups compared to controls, being 0.57 (0.46-0.65) µmol/L (P < 0.01), with the highest levels in the septic shock group, being 0.89 (0.56-1.39) µmol/L. The ratio of hArg:ADMA was inversely correlated with disease severity as determined by the Sequential Organ Failure Assessment (SOFA) score. Receiver-operating characteristic analysis for the presence or absence of septic shock revealed equally high sensitivity and specificity for the hArg:ADMA ratio compared to the SOFA score. DDAH2 expression was lower in patients than controls and lowest in the subgroup of patients with increasing SOFA. CONCLUSIONS: In patients with sepsis, plasma hArg concentrations are decreased and ADMA concentrations are increased. Both metabolites affect NO metabolism and our findings suggest reduced NO bioavailability in sepsis. In addition, reduced expression of DDAH2 in immune cells was observed and may not only contribute to blunted NO signaling but also to subsequent impaired pathogen defense.

The association of the vanin-1 N131S variant with blood pressure is mediated by endoplasmic reticulum-associated degradation and loss of function.

High blood pressure (BP) is the most common cardiovascular risk factor worldwide and a major contributor to heart disease and stroke. We previously discovered a BP-associated missense SNP (single nucleotide polymorphism)-rs2272996-in the gene encoding vanin-1, a glycosylphosphatidylinositol (GPI)-anchored membrane pantetheinase. In the present study, we first replicated the association of rs2272996 and BP traits with a total sample size of nearly 30,000 individuals from the Continental Origins and Genetic Epidemiology Network (COGENT) of African Americans (P=0.01). This association was further validated using patient plasma samples; we observed that the N131S mutation is associated with significantly lower plasma vanin-1 protein levels. We observed that the N131S vanin-1 is subjected to rapid endoplasmic reticulum-associated degradation (ERAD) as the underlying mechanism for its reduction. Using HEK293 cells stably expressing vanin-1 variants, we showed that N131S vanin-1 was degraded significantly faster than wild type (WT) vanin-1. Consequently, there were only minimal quantities of variant vanin-1 present on the plasma membrane and greatly reduced pantetheinase activity. Application of MG-132, a proteasome inhibitor, resulted in accumulation of ubiquitinated variant protein. A further experiment demonstrated that atenolol and diltiazem, two current drugs for treating hypertension, reduce the vanin-1 protein level. Our study provides strong biological evidence for the association of the identified SNP with BP and suggests that vanin-1 misfolding and degradation are the underlying molecular mechanism.

A Cysteine-Specific Fluorescent Switch for Monitoring Oxidative Stress and Quantification of Aminoacylase-1 in Blood Serum.

Reagents that allows detection and monitoring of crucial biomarkers with luminescence ON response have significance in clinical diagnostics. A new coumarin derivative is reported here, which could be used for specific and efficient chemodosimetric detection of cysteine, an important biomarker. The probe is successfully used for studying the biochemical transformation of N-acetylcysteine, a commonly prescribed Cys supplement drug to Cys by aminoacylase-1 (ACY-1), an important and endogenous mammalian enzyme. The possibility of using this reagent for quantification of ACY-1 in blood serum samples is also explored. Nontoxic nature and cell membrane permeability are key features of this probe and are ideally suited for imaging intracellular Cys in normal and cancerous cell lines. Our studies have also revealed that this reagent could be utilized as a redox switch to monitor the hydrogen-peroxide-induced oxidative stress in living SW480 cell lines. Peroxide-mediated cysteine oxidation has a special significance for understanding the cellular-signaling events.

Serum pantetheinase/vanin levels regulate erythrocyte homeostasis and severity of malaria.

Tissue pantetheinase, encoded by the VNN1 gene, regulates response to stress, and previous studies have shown that VNN genes contribute to the susceptibility to malaria. Herein, we evaluated the role of pantetheinase on erythrocyte homeostasis and on the development of malaria in patients and in a new mouse model of pantetheinase insufficiency. Patients with cerebral malaria have significantly reduced levels of serum pantetheinase activity (PA). In mouse, we show that a reduction in serum PA predisposes to severe malaria, including cerebral malaria and severe anemia. Therefore, scoring pantetheinase in serum may serve as a severity marker in malaria infection. This disease triggers an acute stress in erythrocytes, which enhances cytoadherence and hemolysis. We speculated that serum pantetheinase might contribute to erythrocyte resistance to stress under homeostatic conditions. We show that mutant mice with a reduced serum PA are anemic and prone to phenylhydrazine-induced anemia. A cytofluorometric and spectroscopic analysis documented an increased frequency of erythrocytes with an autofluorescent aging phenotype. This is associated with an enhanced oxidative stress and shear stress-induced hemolysis. Red blood cell transfer and bone marrow chimera experiments show that the aging phenotype is not cell intrinsic but conferred by the environment, leading to a shortening of red blood cell half-life. Therefore, serum pantetheinase level regulates erythrocyte life span and modulates the risk of developing complicated malaria.

Value of vanin-1 assessment in adult patients with primary immune thrombocytopenia.

The diagnosis of primary immune thrombocytopenia (ITP) is clinical and cannot be established by any specific laboratory assay. Perhaps the best diagnostic study is assessment of the patient's response to ITP therapy. Oxidative stress-related pathways were among the most significant chronic ITP-associated pathways. Overexpression of VNN1 gene, an oxidative stress sensor in epithelial cells, was most strongly associated with progression to chronic ITP. To address this issue, we tested the hypothesis that blood vanin-1 protein level could distinguish between chronic responders and non-responders ITP patients as well as between ITP patients and healthy controls. Vanin-1 protein levels were determined in peripheral blood leukocytes of 80 adult subjects (16 newly diagnosed ITP patients, 24 chronic responders ITP patients, 24 chronic non-responders ITP patients and 16 healthy controls) by enzyme-linked immunesorbent assay (ELISA). Blood vanin-1 protein levels were lower in controls (median = 18.39 ng) than in ITP patients (median = 58.78 ng) with a highly significant p value (p < 0.001). Vanin-1 levels were highly significantly elevated in newly diagnosed ITP patients (median = 188.62 ng) in comparison to chronic responders (median= 26.90 ng) and chronic non-responders (median = 73.87 ng). Vanin-1 level at a cut-off value of >20.73 ng was found to be 100% sensitive and 93.7% specific in discriminating between newly diagnosed ITP patients and healthy controls. Vanin-1 level was found to be 100% sensitive and 100% specific in differentiating between responders and non-responders with a cut-off value of ≤ 34.5 ng. Our results suggest that vanin-1 can distinguish between chronic responders and non-responders ITP patients as well as between newly diagnosed ITP patients and healthy controls. These findings demonstrate that vanin-1 may contribute to the pathogenesis of ITP, indicating that vanin-1 is an important target for further investigation.

Impact of early parenteral nutrition on metabolism and kidney injury.

A poor nutritional state and a caloric deficit associate with increased morbidity and mortality, but a recent multicenter, randomized controlled trial found that early parenteral nutrition to supplement insufficient enteral nutrition increases morbidity in the intensive care unit, including prolonging the duration of renal replacement therapy, compared with withholding parenteral nutrition for 1 week. Whether early versus late parenteral nutrition impacts the incidence and recovery of AKI is unknown. Here, we report a prespecified analysis from this trial, the Early Parenteral Nutrition Completing Enteral Nutrition in Adult Critically Ill Patients (EPaNIC) study. The timing of parenteral nutrition did not affect the incidence of AKI, but early initiation seemed to slow renal recovery in patients with stage 2 AKI. Early parenteral nutrition did not affect the time course of creatinine and creatinine clearance but did increase plasma urea, urea/creatinine ratio, and nitrogen excretion beginning on the first day of amino acid infusion. In the group that received late parenteral nutrition, infusing amino acids after the first week also increased ureagenesis. During the first 2 weeks, ureagenesis resulted in net waste of 63% of the extra nitrogen intake from early parenteral nutrition. In conclusion, early parenteral nutrition does not seem to impact AKI incidence, although it may delay recovery in patients with stage 2 AKI. Substantial catabolism of the extra amino acids, which leads to higher levels of plasma urea, might explain the prolonged duration of renal replacement therapy observed with early parenteral nutrition.

Effect of lowering asymmetric dimethylarginine (ADMA) on vascular pathology in atherosclerotic ApoE-deficient mice with reduced renal mass.

The purpose of the work was to study the impact of the endogenous nitric oxide synthase (NOS) inhibitor asymmetric dimethylarginine (ADMA) and its degrading enzyme, dimethylarginine dimethylaminohydrolase (DDAH1), on atherosclerosis in subtotally nephrectomized (SNX) ApoE-deficient mice. Male DDAH1 transgenic mice (TG, n=39) and C57Bl/6J wild-type littermates (WT, n=27) with or without the deletion of the ApoE gene underwent SNX at the age of eight weeks. Animals were sacrificed at 12 months of age, and blood chemistry, as well as the extent of atherosclerosis within the entire aorta were analyzed. Sham treated (no renal mass reduction) ApoE-competent DDAH1 transgenic and wild-type littermates (n=11) served as a control group. Overexpression of DDAH1 was associated with significantly lower ADMA levels in all treatment groups. Surprisingly, SNX mice did not exhibit higher ADMA levels compared to sham treated control mice. Furthermore, the degree of atherosclerosis in ApoE-deficient mice with SNX was similar in mice with or without overexpression of DDAH1. Overexpression of the ADMA degrading enzyme, DDAH1, did not ameliorate atherosclerosis in ApoE-deficient SNX mice. Furthermore, SNX in mice had no impact on ADMA levels, suggesting a minor role of this molecule in chronic kidney disease (CKD) in this mouse model.

Endocannabinoids and related lipids linked to social exclusion in individuals with chronic non-medical prescription opioid use.

Opioid-related overdose deaths are still on the rise in North America, emphasizing the need to better understand the underlying neurobiological mechanisms regarding the development of opioid use disorder (OUD). Recent evidence from preclinical and clinical studies indicate that the endocannabinoid system (ECS) may play a crucial role in stress and reward, both involved in the development and maintenance of substance use disorders. Animal models demonstrate a specific crosstalk between the ECS and the endogenous opioid system. However, translational studies in humans are scarce. Here, we investigated basal plasma levels of the endocannabinoids anandamide (AEA) and 2-arachidonoyglycerol (2-AG), and eight endocannabinoid-related lipids, including oleoylethanolamide (OEA) and palmitoylethanolamide (PEA), as well as whole blood fatty acid amide hydrolase (FAAH) activity in chronic non-medical prescription opioid users (NMPOU; n = 21) compared to opioid-naïve healthy controls (n = 29) considering age, sex, and cannabis use as potential confounders. Additionally, the association of endocannabinoids and related lipids with the participants' response to experimentally induced social exclusion was examined. We found significantly elevated basal AEA, OEA, and PEA levels in NMPOU compared to controls, but no differences in FAAH activity, 2-AG, or other endocannabinoid-related lipids. Within NMPOU, higher AEA levels were associated with lower perception of social exclusion. Robust positive correlations within N-acylethanolamines (i.e., AEA, OEA, and PEA) indicate strong metabolic associations. Together with our recent findings of elevated basal 2-AG levels in dependent cocaine users, present results indicate substance-specific alterations of the ECS that may have implications in the search for novel therapeutic interventions for these populations.

Biomarkers of acute injury: predicting the long-term outcome after transplantation.

Biomarkers of ischemia-reperfusion injury allow risk stratification and early identification of delayed graft function after kidney transplantation. Welberry Smith et al. describe a novel serum biomarker, aminoacylase-1, that not only is associated with delayed graft function but can predict the long-term outcome years after transplantation.

Serum aminoacylase-1 is a novel biomarker with potential prognostic utility for long-term outcome in patients with delayed graft function following renal transplantation.

Early identification and prognostic stratification of delayed graft function following renal transplantation has significant potential to improve outcome. Mass spectrometry analysis of serum samples, before and on day 2 post transplant from five patients with delayed graft function and five with an uncomplicated transplant, identified aminoacylase-1 (ACY-1) as a potential outcome biomarker. Following assay development, analysis of longitudinal samples from an initial validation cohort of 55 patients confirmed that the ACY-1 level on day 1 or 2 was a moderate predictor of delayed graft function, similar to serum creatinine, complementing the strongest predictor cystatin C. A further validation cohort of 194 patients confirmed this association with area under ROC curves (95% CI) for day 1 serum (138 patients) of 0.74 (0.67-0.85) for ACY-1, 0.9 (0.84-0.95) for cystatin C, and 0.93 (0.88-0.97) for both combined. Significant differences in serum ACY-1 levels were apparent between delayed, slow, and immediate graft function. Analysis of long-term follow-up for 54 patients with delayed graft function showed a highly significant association between day 1 or 3 serum ACY-1 and dialysis-free survival, mainly associated with the donor-brain-dead transplant type. Thus, proteomic analysis provides novel insights into the potential clinical utility of serum ACY-1 levels immediately post transplantation, enabling subdivision of patients with delayed graft function in terms of long-term outcome. Our study requires independent confirmation.

Polycystic kidneys have decreased vascular density: a micro-CT study.

OBJECTIVE: Polycystic kidney disease (PKD) is a common cause of end-stage renal failure and many of these patients suffer vascular dysfunction and hypertension. It remains unclear whether PKD is associated with abnormal microvascular structure. Thus, this study examined the renovascular structure in PKD. METHODS: PKD rats (PCK model) and controls were studied at 10 weeks of age, and mean arterial pressure (MAP), renal blood flow, and creatinine clearance were measured. Microvascular architecture and cyst number and volume were assessed using micro-computed tomography, and angiogenic pathways evaluated. RESULTS: Compared with controls, PKD animals had an increase in MAP (126.4 ± 4.0 vs. 126.2 ± 2.7 mmHg) and decreased clearance of creatinine (0.39 ± 0.09 vs. 0.30 ± 0.05 mL/min), associated with a decrease in microvascular density, both in the cortex (256 ± 22 vs. 136 ± 20 vessels per cm2) and medullar (114 ± 14 vs. 50 ± 9 vessels/cm2) and an increase in the average diameter of glomeruli (104.14 ± 2.94 vs. 125.76 ± 9.06 mm). PKD animals had increased fibrosis (2.2 ± 0.2 fold vs. control) and a decrease in the cortical expression in hypoxia inducible factor 1-α and vascular endothelial growth factor. CONCLUSIONS: PKD animals have impaired renal vascular architecture, which can have significant functional consequences. The PKD microvasculature could represent a therapeutic target to decrease the impact of this disease.

Effects of salvianolic acid A on plasma and tissue dimethylarginine levels in a rat model of myocardial infarction.

: This study aimed to investigate the effects of salvianolic acid A (Sal A) on the time course of plasma and tissue dimethylarginine levels after myocardial infarction (MI) induced by left coronary artery ligation. The rats were assigned to 4 groups: Sham, MI, and MI treated with Sal A (1 or 5 mg/kg). The results showed that plasma symmetric dimethylarginine and asymmetric dimethylarginine (ADMA) levels separately reached the peak at the first and second day after MI. Dimethylarginine dimethylaminohydrolase (DDAH) activity in the heart was remarkably inhibited on the initial 2 days. Sal A restored DDAH activity in the heart and decreased the elevated plasma ADMA levels. ADMA concentrations in the heart and liver were significantly increased after MI, which could also be reduced by Sal A. In addition, Sal A showed regulating effects on symmetric dimethylarginine levels in the liver and also in the ischemic zone of heart. In conclusion, the variations of dimethylarginines in plasma and tissues were induced by the inhibition of DDAH activity and their leakage in the infarct zone after MI. Sal A exerted beneficial effects in MI by decreasing plasma and tissue dimethylarginine levels via restoring DDAH activity.