Disrupted iron regulation in the brain and periphery in cocaine addiction

Stimulant drugs acutely increase dopamine neurotransmission in the brain, and chronic use leads to neuroadaptive changes in the mesolimbic dopamine system and morphological changes in basal ganglia structures. Little is known about the mechanisms underlying these changes but preclinical evidence suggests that iron, a coenzyme in dopamine synthesis and storage, may be a candidate mediator. Iron is present in high concentrations in the basal ganglia and stimulant drugs may interfere with iron homeostasis. We hypothesised that morphological brain changes in cocaine addiction relate to abnormal iron regulation in the brain and periphery. We determined iron concentration in the brain, using quantitative susceptibility mapping, and in the periphery, using iron markers in circulating blood, in 44 patients with cocaine addiction and 44 healthy controls. Cocaine-addicted individuals showed excess iron accumulation in the globus pallidus, which strongly correlated with duration of cocaine use, and mild iron deficiency in the periphery, which was associated with low iron levels in the red nucleus. Our findings show that iron dysregulation occurs in cocaine addiction and suggest that it arises consequent to chronic cocaine use. Putamen enlargement in these individuals was unrelated to iron concentrations, suggesting that these are co-occurring morphological changes that may respectively reflect predisposition to, and consequences of cocaine addiction. Understanding the mechanisms by which cocaine affects iron metabolism may reveal novel therapeutic targets, and determine the value of iron levels in the brain and periphery as biomarkers of vulnerability to, as well as progression and response to treatment of cocaine addiction

Urinary hepcidin levels in iron-deficient and iron-supplemented piglets correlate with hepcidin hepatic mRNA and serum levels and with body iron status

Among livestock, domestic pig (Sus scrofa) is a species, in which iron metabolism has been most intensively examined during last decade. The obvious reason for studying the regulation of iron homeostasis especially in young pigs is neonatal iron deficiency anemia commonly occurring in these animals. Moreover, supplementation of essentially all commercially reared piglets with iron entails a need for monitoring the efficacy of this routine practice followed in the swine industry for several decades. Since the discovery of hepcidin many studies confirmed its role as key regulator of iron metabolism and pointed out the assessment of its concentrations in biological fluids as diagnostic tool for iron-related disorder. Here we demonstrate that urine hepcidin-25 levels measured by a combination of weak cation exchange chromatography and time-of-flight mass spectrometry (WCX-TOF MS) are highly correlated with mRNA hepcidin expression in the liver and plasma hepcidin-25 concentrations in anemic and iron-supplemented 28-day old piglets. We also found a high correlation between urine hepcidin level and hepatic non-heme iron content. Our results show that similarly to previously described transgenic mouse models of iron disorders, young pigs constitute a convenient animal model to explore accuracy and relationship between indicators for assessing systemic iron status

Publisher Correction: Tubular iron deposition and iron handling proteins in human healthy kidney and chronic kidney disease)

Correction to: Scientific Reports https://doi.org/10.1038/s41598-018-27107-8, published online 19 June 201

Identification of novel translational urinary biomarkers for acetaminophen-induced acute liver injury using proteomic profiling in mice

Contains fulltext : 108207.pdf (publisher's version ) (Open Access)Drug-induced liver injury (DILI) is the leading cause of acute liver failure. Currently, no adequate predictive biomarkers for DILI are available. This study describes a translational approach using proteomic profiling for the identification of urinary proteins related to acute liver injury induced by acetaminophen (APAP). Mice were given a single intraperitoneal dose of APAP (0-350 mg/kg bw) followed by 24 h urine collection. Doses of >/=275 mg/kg bw APAP resulted in hepatic centrilobular necrosis and significantly elevated plasma alanine aminotransferase (ALT) values (p<0.0001). Proteomic profiling resulted in the identification of 12 differentially excreted proteins in urine of mice with acute liver injury (p<0.001), including superoxide dismutase 1 (SOD1), carbonic anhydrase 3 (CA3) and calmodulin (CaM), as novel biomarkers for APAP-induced liver injury. Urinary levels of SOD1 and CA3 increased with rising plasma ALT levels, but urinary CaM was already present in mice treated with high dose of APAP without elevated plasma ALT levels. Importantly, we showed in human urine after APAP intoxication the presence of SOD1 and CA3, whereas both proteins were absent in control urine samples. Urinary concentrations of CaM were significantly increased and correlated well with plasma APAP concentrations (r = 0.97; p<0.0001) in human APAP intoxicants, who did not present with elevated plasma ALT levels. In conclusion, using this urinary proteomics approach we demonstrate CA3, SOD1 and, most importantly, CaM as potential human biomarkers for APAP-induced liver injury

Inhibition of Nrf2 alters cell stress induced by chronic iron exposure in human proximal tubular epithelial cells

Iron can catalyze reactive oxygen species (ROS) formation, causing cellular injury. In systemic iron overload, renal tubular epithelial cells are luminally exposed to high iron levels due to glomerular filtration of increased circulating iron. Reports of tubular dysfunction and iron deposition in β-thalassemia major support an association between increased chronic iron exposure and renal tubular injury. In acute iron exposure, Nuclear factor-erythroid 2-related factor 2 (Nrf2) may protect from iron-induced injury, whereas chronic renal stress may lead to Nrf2 exhaustion. We studied the cytotoxic mechanisms of chronic iron exposure using human conditionally immortalized proximal tubular epithelial cells (ciPTECs). Long-term iron exposure resulted in iron accumulation, cytosolic ROS formation and increased heme oxygenase 1 (HMOX-1) mRNA expression (all p < 0.001). This was accompanied by nuclear translocation of Nrf2 and induction of its target protein NQO1, which both could be blocked by the Nrf2 inhibitor trigonelline. Interestingly, iron and trigonelline incubation reduced ROS production, but did not affect HMOX-1 mRNA levels. Moreover, ferritin protein and CHOP mRNA expression were induced in combined iron and trigonelline incubated cells (p < 0.05). Together, these findings suggest that chronic iron exposure induces oxidative stress and that exhaustion of the antioxidant Nrf2 pathway may lead to renal injury

Urinary protein profiling in hyperactive delirium and non-delirium cardiac surgery ICU patients

Suitable biomarkers associated with the development of delirium are still not known. Urinary proteomics has successfully been applied to identify novel biomarkers associated with various disease states, but its value has not been investigated in delirium patients. In a prospective explorative study hyperactive delirium patients after cardiac surgery were included for urinary proteomic analyses. Delirium patients were matched with non-delirium patients after cardiac surgery on age, gender, severity of illness score, LOS-ICU, Euro-score, C-reactive protein, renal function and aorta clamping time. Urine was collected within 24 hours after the onset of delirium. Matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF MS) was applied to detect differences in the urinary proteome associated with delirium in these ICU patients. We included 10 hyperactive delirium and 10 meticulously matched non-delirium post-cardiac surgery patients. No relevant differences in the urinary excretion of proteins could be observed

Application of urine proteomics for biomarker discovery in drug-induced liver injury

Abstract The leading cause of hepatic damage is drug-induced liver injury (DILI), for which currently no adequate predictive biomarkers are available. Moreover, for most drugs related to DILI, the mechanisms underlying the adverse reaction have not yet been elucidated. Urinary protein biomarker candidates for DILI have emerged in the past few years and correlate well with clinical studies for serum DILI biomarkers. The goal of this review was to investigate the use of urine as a source of protein biomarkers for drug-induced liver injury. Finally, we discuss some of the current strategies required to advance the field of biomarker discovery for DILI with respect to appropriate clinical biobanking and adequate translational research

Towards Evidence Based Integrated Care

Abstract Introduction: Both in literature and in practice there is debate about defining Integrated Care. The WHO for example, defines Integrated Care as a process, not covering the perspective of (cost-) effectiveness. From the perspective of research into evidence in Integrated Care this is rather awkward. Triple aim focusses on 1) quality of life of citizens; 2) quality and continuity of care and, 3) cost effective care. Integrated Care is aimed at well-organized, cost-effective processes of care delivery, provided by committed professionals which must be able to count on well-established evidence for the care interventions they provide in integrated trajectories to their patients. Research should support them both with evidence for effective interventions and evidence for effective application. A basis for thorough research in Integrated Care is narrowed by a lack of a comprehensive definition. Theory/Methods: Since Integrated Care is considered as sets of complex interventions targeting triple aim, we compared definitions of Integrated Care reported in literature with a definition of complex interventions and a model for evidence based developing, testing and implementing complex interventions. This definition and the accompanied model are issued by the British Medical Research Council (MRC) in 2008 and are nowadays worldwide established. During the session at the conference, after a short introduction, we will discuss our proposal with the participants for improving a new definition of evidence based integrated care

Renal Handling of Circulating and Renal-Synthesized Hepcidin and Its Protective Effects against Hemoglobin-Mediated Kidney Injury.

Item does not contain fulltextUrinary hepcidin may have protective effects against AKI. However, renal handling and the potential protective mechanisms of hepcidin are not fully understood. By measuring hepcidin levels in plasma and urine using mass spectrometry and the kidney using immunohistochemistry after intraperitoneal administration of human hepcidin-25 (hhep25) in C57Bl/6N mice, we showed that circulating hepcidin is filtered by the glomerulus and degraded to smaller isoforms detected in urine but not plasma. Moreover, hepcidin colocalized with the endocytic receptor megalin in proximal tubules, and compared with wild-type mice, megalin-deficient mice showed higher urinary excretion of injected hhep25 and no hepcidin staining in proximal tubules that lack megalin. This indicates that hepcidin is reaborbed in the proximal tubules by megalin dependent endocytosis. Administration of hhep25 concomitant with or 4 hours after a single intravenous dose of hemoglobin abolished hemoglobin-induced upregulation of urinary kidney injury markers (NGAL and KIM-1) and renal Interleukin-6 and Ngal mRNA observed 24 hours after administration but did not affect renal ferroportin expression at this point. Notably, coadministration of hhep25 and hemoglobin but not administration of either alone greatly increased renal mRNA expression of hepcidin-encoding Hamp1 and hepcidin staining in distal tubules. These findings suggest a role for locally synthesized hepcidin in renal protection. Our observations did not support a role for ferroportin in hhep25-mediated protection against hemoglobin-induced early injury, but other mechanisms of cellular iron handling may be involved. In conclusion, our data suggest that both systemically delivered and locally produced hepcidin protect against hemoglobin-induced AKI