Plasma Heme Oxygenase-1 Research Articles

Chitinase and indoleamine 2, 3-dioxygenase are prognostic biomarkers for unfavorable treatment outcomes in pulmonary tuberculosis.

Chitinase, Indoleamine 2,3-dioxygenesae-1 (IDO-1) and heme oxygenase-1 (HO-1) are candidate diagnostic biomarkers for tuberculosis (TB). Whether these immune markers could also serve as predictive biomarkers of unfavorable treatment outcomes in pulmonary TB (PTB) is not known. A cohort of newly diagnosed, sputum culture-positive adults with drug-sensitive PTB were recruited. Plasma chitinase protein, IDO protein and HO-1 levels measured before treatment initiation were compared between 68 cases with unfavorable outcomes (treatment failure, death, or recurrence) and 108 control individuals who had recurrence-free cure. Plasma chitinase and IDO protein levels but not HO-1 levels were lower in cases compared to controls. The low chitinase and IDO protein levels were associated with increased risk of unfavourable outcomes in unadjusted and adjusted analyses. Receiver operating characteristic analysis revealed that chitinase and IDO proteins exhibited high sensitivity and specificity in differentiating cases vs controls as well as in differentiating treatment failure vs controls and recurrence vs controls, respectively. Classification and regression trees (CART) were used to determine threshold values for these two immune markers. Our study revealed a plasma chitinase and IDO protein signature that may be used as a tool for predicting adverse treatment outcomes in PTB.

Heme oxygenase-1 as a predictor of sepsis-induced acute kidney injury: a cross-sectional study.

Sepsis patients suffer from severe inflammation and poor prognosis. Oxidative stress and local inflammation that results from sepsis can trigger organ injury, including acute kidney injury (AKI). Previous studies have shown that heme oxygenase-1 (HO-1) is overexpressed in proximal tubular cells under oxidative stress and has significant cytoprotective and anti-inflammatory effects. Heme-induced inflammation in sepsis is antagonized by increased tissue expression of heme oxygenase-1 (HO-1), which impacts on AKI development. The investigators observed intrarenal HO-1 expression and corresponding potential increases in plasma and urinary HO-1 protein concentrations in four different AKI models. Since serum levels of HO-1 reflect HO-1 expression, we aimed to investigate whether serum HO-1 could predict the development of AKI in sepsis patient. A total of 83 sepsis patients were enrolled in this study including septic patients with AKI and sepsis patients without AKI. According to the definition of septic shock and the global kidney diagnostic criteria described in the Kidney Disease: Improving Global Outcomes (KDIGO), patients were allocated to the sepsis and septic shock groups with and without AKI, respectively. The serum levels of HO-1 were measured by enzyme-linked immunosorbent assays (ELISA). Statistical analyses were performed using SPSS software. There were statistically significant differences between septic patients with AKI and sepsis patients without AKI in terms of Sequential Organ Failure Assessment (SOFA) score, hospitalization time, and laboratory indicators including serum HO-1, creatine kinase MB (CK-MB), troponin I (TnI), urea, myoglobin (MYO), serum creatinine (Scr), procalcitonin, and activated partial thromboplastin time. Serum levels of alkaline phosphatase (ALP), urea, MYO, Scr, procalcitonin, activated partial thromboplastin time, and prothrombin time exhibited significant differences among the four groups. The concentration of serum HO-1 was higher in sepsis-induced AKI compared with sepsis patients without AKI. Serum HO-1 levels were increased in patients with sepsis shock-induced AKI. The area under the receiver operating characteristic (ROC) curve for serum HO-1 combined with Scr was 0.885 [95% confidence interval (CI): 0.761-1.000]. Serum HO-1 is positively correlated with sepsis-induced AKI. These findings suggest that measurement of serum HO-1 may play a diagnostic and prediction role in sepsis-induced AKI.

Association of Circulating Heme Oxygenase-1, Lipid Profile and Coronary Disease Phenotype in Patients with Chronic Coronary Syndrome.

Background. The NF-E2–related factor 2 (Nrf2)/Heme Oxygenase-1 (HO-1) pathway has an emerging role in atherosclerosis. Activated by oxidative stress, it is deemed to exert athero-protective effects. We aimed at evaluating the relationships between plasma HO-1, clinical/molecular profiles and coronary disease patterns in patients with chronic coronary syndromes (CCS). Methods. HO-1 was measured in 526 patients (60 ± 9 years, 318 males) with CCS. Coronary computed tomography angiography (CTA) and stress imaging were used to assess the disease phenotype (coronary atherosclerosis and myocardial ischemia) in a subgroup of 347 patients. Results. In the overall population, HO-1 median value (25–75 percentile) was 5.195 (1.75–8.25) ng/mL. Patients with higher HO-1 were more frequently male, had a higher BMI and lower LVEF%, but otherwise similar risk factors than the other patients. Their bio-humoral profile was characterized by higher markers of endothelial/myocardial dysfunction, but lower levels of cholesterol lipoproteins. Coronary artery disease was characterized by more diffuse atherosclerosis, with mainly non-obstructive and calcified plaques, and a higher prevalence of functional ischemia. Conclusion: In patients with CCS, higher plasma HO-1 levels are associated with lower cholesterol and a more diffuse but mainly non-obstructive coronary atherosclerosis, confirming a potential role for the Nrf2/HO-1 pathway as a protective feedback.

Study on heme oxygenase-1 and HAP model for the diagnosis of chronic hepatitis B-related liver fibrosis

Objective: To determine the diagnostic value of plasma heme oxygenase 1 (HO-1) in the occurrence, development, and pathological stages of chronic hepatitis B-related liver fibrosis. Methods: 211 outpatients and inpatients with chronic hepatitis B (CHB) and 57 healthy controls who visited the Third Hospital of Hebei Medical University were selected. Simultaneously, clinical data, peripheral blood routine and serum biochemical test results of the research subjects were collected. Plasma HO-1 levels were detected by enzyme-linked immunosorbent assay (ELISA). Liver fibrosis (S1 ~ 4) was staged according to liver biopsy and liver stiffness measurement (LSM). Statistical analysis: binary logistic regression was used to analyze the independent risk factors of hepatitis B-related liver fibrosis to establish a diagnostic model, and the receiver operating characteristic curve (ROC) was used to compare and analyze the staging efficiency of HO-1, new model, FIB-4 and APRI for the diagnosis of liver fibrosis. Results: Plasma HO-1 levels were significantly higher in CHB patients than healthy controls [10.11 (7.08 ~ 13.12) ng/ml and 6.71 (5.56 ~ 8.45) ng/ml, (P < 0.001)]. There were 37, 38, 38, and 98 cases with liver fibrosis stages S1, S2, S3, and S4, respectively and plasma HO-1 level was (6.91 ± 2.80) ng/ml, (8.24 ± 2.44) ng/ml, (9.96 ± 3.46) ng/ml, (12.65 ± 3.70) ng/ml, P < 0.001. HO-1, albumin, and platelets (PLT) were independent risk factors for liver fibrosis. A HAP model was established. HAP, FIB-4 and APRI sensitivity and specificity for the diagnosis of liver fibrosis staging were as follows: ≥S2 were 84.62%, 72.35 %, 81.18% and 83.78%, 81.08%, 67.57%; ≥S3 were 80.15%, 82.09%, 85.82% and 88.64%, 76.19%, 60.32%; S4 were 90.82%, 82.29%, 86.46% and 74.37%, 65.77%, 48.65%, respectively. Conclusion: Plasma HO-1 level can reflect the severity of liver fibrosis. HAP diagnostic model can more accurately mirror the process of liver fibrosis than FIB-4 and APRI, and point clinical diagnosis and prognosis assessment.

Electronic and Tobacco Cigarettes Alter Polyunsaturated Fatty Acids and Oxidative Biomarkers.

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Heme oxygenase-1 in blood and saliva during acute psychosis: A pilot study

Despite the extensive prevalence of psychosis and schizophrenia spectrum disorders, their biological underpinnings remain largely unexplained. Recently, the overproduction of heme oxygenase-1 (HO-1), an enzyme that catalyzes the degradation of heme, was associated with oxidative stress and a neurologic phenotype similar to schizophrenia in transgenic mice. We sought to evaluate, by comparing patients experiencing an acute psychotic episode, and age/sex-matched healthy control participants, whether there was an association between HO-1 overexpression and psychosis. This cross-sectional pilot study included 16 patients and 17 control participants. Enzyme-linked immunosorbent assay and quantitative real-time polymerase chain reaction were used to quantify HO-1 expression in blood and saliva. Four psychiatric questionnaires were used to measure psychiatric symptoms in participants. Higher levels of salivary HO-1 expression were detected in patients experiencing an acute psychotic episode when compared to control participants (84.01 vs. 61.26 ng/ml, p = 0.026), but plasma and lymphocyte HO-1 expression did not significantly differ between groups. Overexpression of HO-1 in saliva specimens was also positively associated with psychiatric symptom severity and disability. The overexpression of HO-1 in the saliva of patients with psychosis suggests that it may serve as a potential biomarker for this symptom which should be explored in larger clinical trials.

Increased Plasma Heme Oxygenase-1 Levels in Patients With Early-Stage Parkinson's Disease.

Introduction: Heme oxygenase-1 (HO-1) is a 32 kDa stress-response protein implicated in the pathogenesis of Parkinson’s disease (PD). Biliverdin is derived from heme through a reaction mediated by HO-1 and protects cells from oxidative stress. However, iron and carbon monoxide produced by the catabolism of HO-1 exert detrimental effects on patients with PD. The purpose of this study was to determine whether plasma HO-1 levels represent a biomarker of PD and to further explore the underlying mechanism of increased HO-1 levels by applying voxel-based morphometry (VBM).Methods: We measured plasma HO-1 levels using an enzyme-linked immunosorbent assay (ELISA) in 156 subjects, including 81 patients with early- and advanced-stage PD and 75 subjects without PD. The analyses were adjusted to control for confounders such as age, sex, and medication. We analyzed T1-weighted magnetic resonance imaging (MRI) data from 74 patients with PD using VBM to elucidate the association between altered brain volumes and HO-1 levels. Then, we compared performance on MMSE sub-items between PD patients with low and high levels of HO-1 using Mann-Whitney U tests.Results: Plasma HO-1 levels were significantly elevated in PD patients, predominantly those with early-stage PD, compared with controls (p < 0.05). The optimal cutoff value for patients with early PD was 2.245 ng/ml HO-1 [area under the curve (AUC) = 0.654]. Plasma HO-1 levels were unaffected by sex, age, and medications (p > 0.05). The right hippocampal volume was decreased in the subset of PD patients with high HO-1 levels (p < 0.05). A weak correlation was observed between right hippocampal volume and plasma HO-1 levels (r = −0.273, p = 0.018). There was no difference in total MMSE scores between the low- and high-HO-1 groups (p > 0.05), but the high-HO-1 group had higher language scores than the low-HO-1 group (p < 0.05).Conclusions: Plasma HO-1 levels may be a promising biomarker of early PD. Moreover, a high plasma concentration of the HO-1 protein is associated with a reduction in right hippocampal volume.

Heme as Possible Contributing Factor in the Evolvement of Shiga-Toxin Escherichia coli Induced Hemolytic-Uremic Syndrome.

Shiga-toxin (Stx)-producing Escherichia coli hemolytic-uremic syndrome (STEC-HUS) is one of the most common causes of acute kidney injury in children. Stx-mediated endothelial injury initiates the cascade leading to thrombotic microangiopathy (TMA), still the exact pathogenesis remains elusive. Interestingly, there is wide variability in clinical presentation and outcome. One explanation for this could be the enhancement of TMA through other factors. We hypothesize that heme, as released during extensive hemolysis, contributes to the etiology of TMA. Plasma levels of heme and its scavenger hemopexin and degrading enzyme heme-oxygenase-1 (HO-1) were measured in 48 STEC-HUS patients. Subsequently, the effect of these disease-specific heme concentrations, in combination with Stx, was assessed on primary human glomerular microvascular endothelial cells (HGMVECs). Significantly elevated plasma heme levels up to 21.2 µM were found in STEC-HUS patients compared to controls and were inversely correlated with low or depleted plasma hemopexin levels (R2 −0.74). Plasma levels of HO-1 are significantly elevated compared to controls. Interestingly, especially patients with high heme levels (n = 12, heme levels above 75 quartile range) had high plasma HO-1 levels with median of 332.5 (86–720) ng/ml (p = 0.008). Furthermore, heme is internalized leading to a significant increase in reactive oxygen species production and stimulated both nuclear translocation of NF-κB and increased levels of its target gene (tissue factor). In conclusion, we are the first to show elevated heme levels in patients with STEC-HUS. These increased heme levels mediate endothelial injury by promoting oxidative stress and a pro-inflammatory and pro-thrombotic state. Hence, heme may be a contributing and driving factor in the pathogenesis of STEC-HUS and could potentially amplify the cascade leading to TMA.

Abstract 15702: Chronic Use of Electronic or Tobacco Cigarettes Alters Circulating Polyunsaturated Fatty Acids, Oxidation Status and Cardiovascular Risk in Healthy Young Adults

Introduction: Electronic cigarettes (EC) have recently gained unprecedented popularity with over 5 million users in the United States. However, it is not known whether chronic EC use induces cardiovascular health effects in healthy young adults. Hypothesis: We hypothesized that chronic EC use ≥1 year affects lipid peroxidation and/or antioxidant defense in the circulating blood, as compared to chronic tobacco cigarette (TC) smokers. Methods: We enrolled EC-users (n=32), TC-smokers (n=29) and non-users (n=45) with mean ages of 28.3, 27.8 and 27.4 years, respectively. Plasma concentrations of polyunsaturated fatty acids and oxidized metabolites were assessed by liquid chromatography coupled to ion trap mass spectrometry. Total antioxidant capacity (TAC), heme oxygenase-1 (HO-1) and functional activity of paraoxonase1 (PON1) and arylesterase were determined by colorimetric and enzymatic assays in the plasma. Multivariable analysis was performed using classification models aimed at segregating subjects based on biomarker profiles. Results: As shown in table 1, EC-users and TC-smokers exhibited significant alterations in oxidized linoleic acid (LA) metabolites (9- and 13-hydroxyoctadecadienoic acid (HODE)), arachidonic acid (AA), LA, TAC and HO-1. Multivariable analysis identified a set of 5 biomarkers (13-HODE, LA, 9-HODE, 12-hydroxyeicosatetraenoic acid (HETE), and AA) that discriminated EC-users from TC-smokers and non-users with an overall accuracy of 73.4%. Conclusions: Chronic use of EC induces both common (i.e. reduced 9- and 13-HODEs, and increased TAC) as well as differential effects (i.e. altered concentrations of AA and LA) to those induced by TC, along with intermediate plasma HO-1 concentrations, suggesting that EC, likewise TC smoke, could impact cardiovascular risk.

Application of heme oxygenase 1 in the diagnosis of non-alcoholic fatty liver disease

Objective: To explore the clinical value of plasma heme oxygenase 1(HO-1) in the development of non-alcoholic fatty liver disease(NAFLD). Methods: Patients with NAFLD were selected from the Physical examination center and the Department of Traditional and Western Medical Hepatology of Third Hospital of Hebei Medical University. A combination of ultrasound and liver elastography was used to screen NAFLD patients and healthy persons. General clinical characteristics, peripheral blood cell count and liver biochemical test results were collected synchronously, plasma samples were retained, and plasma HO-1 level was detected by enzyme-linked immunosorbent assay. SPSS21.0 statistical software was used for statistical analysis, multivariate logistic regression analyses was used to analyse the independent risk factors affecting the incidence and progression of NAFLD. The diagnostic efficacy of indicators related to development of NAFLD was assessed by the receiver operating characteristic curve(ROC). Results: A total of 328 patients with NAFLD and 113 healthy controls were included. According to the liver biochemical results, the NAFLD group was divided into 148 patients with normal liver enzymes and 180 patients with abnormal liver enzymes. The level of HO-1 in the three groups was 9.09 ± 2.19, 14.38 ± 2.63, 17.00 ± 3.30 ng/ml, and was increased respectively of healthy controls, patients with normal liver enzymes and patients with abnormal liver enzymes. Analyzing plasma HO-1 levels of components associated with metabolic disorders suggests that components without metabolic syndrome(9.83 ± 3.21) < components with 1 metabolic syndrome(13.59 ± 3.72) < components with 2 or more metabolic syndrome(16.09 ± 3.41), P < 0.001. The results of HO-1 level stratification analysis showed that WBC, ALT, AST, GGT, TG increased as HO-1 level increased, and the pairwise difference was statistically significant (P < 0.001). The WBC count of NAFLD is significantly higher than healthy group(6.79 ± 1.62 vs 5.68 ± 1.36, P < 0.001). The univariate and multivariate regression analyses of all the subjects showed that HO-1, TG and BMI were prognostic factors for the occurrence of NAFLD and HO-1, TC, GLU were prognostic factors for the progression of NAFLD, P < 0.05. The ROC analysis showed that HO-1 was reliable markers for predicting the occurrence and progression of NALFD, the sensitivity and specificity were respectively 85.10%, 92.90% and 38.33%, 95.27%. Conclusion: Plasma HO-1 can predict the occurrence and progression of NAFLD and is expected to be a novel molecular diagnostic marker for NAFLD and NASH.

963. Whole Blood Transcriptome Analysis Reveals Differences in Erythropoiesis and Neurologically Relevant Pathways Between Cerebral Malaria and Severe Malarial Anemia

Background Plasmodium falciparum malaria can rapidly progress to severe disease that can lead to death if left untreated. Severe malaria cases commonly present as severe malarial anemia (SMA), defined in children as hemoglobin (Hb) <5 g/dL with parasitemia, or as cerebral malaria (CM), which manifests as parasitemia with acute neurological deficits and has an inpatient mortality rate of ~20%. The molecular and cellular processes that lead to CM and SMA are unclear.MethodsIn a cross-sectional study, we compared genome-wide transcription profiles of whole blood obtained from Ugandan children with acute CM (n = 17) or SMA (n = 17) and community children without P. falciparum infection (n = 12) who were enrolled in a parent cohort study of severe malaria. We determined the relationships between gene expression, hematological indices, and plasma biomarkers, including inflammatory cytokines.ResultsBoth CM and SMA demonstrated enrichment of dendritic cell activation, inflammatory/TLR/chemokines, monocyte, and neutrophil modules but depletion of lymphocyte modules. Neurodegenerative disease and neuroinflammation pathways were enriched in CM. Increased Nrf2 pathway gene expression corresponded with increased plasma heme oxygenase-1 and the heme catabolite bilirubin in a manner specific to children with both SMA and sickle cell disease. Reticulocyte-specific gene expression was markedly decreased in CM relative to SMA despite higher Hb levels and appropriate increases in plasma erythropoietin. Viral sensing/interferon regulatory factor (IRF) 2 module (M111) expression and plasma IP-10 levels both negatively correlated with reticulocyte-specific signatures, but only M111 expression independently predicted decreased reticulocyte-specific gene expression after controlling for leukocyte count, Hb level, parasitemia, and clinical syndrome by multiple regression.ConclusionDifferences in the blood transcriptome of CM and SMA relate to neurologically relevant pathways and erythropoiesis. Erythropoietic suppression during severe malaria is more pronounced during CM versus SMA and is positively associated with IRF2 blood signatures. Future studies are needed to validate these findings.Disclosures All authors: No reported disclosures.

Intravenous Heme Arginate Induces HO-1 (Heme Oxygenase-1) in the Human Heart.

Objective- HO-1 (heme oxygenase-1) induction may prevent or reduce ischemia-reperfusion injury. We previously evaluated its in vivo induction after a single systemic administration of heme arginate in peripheral blood mononuclear cells. The current trial was designed to assess the pharmacological tissue induction of HO-1 in the human heart with heme arginate in vivo. Approach and Results- Patients planned for conventional aortic valve replacement received placebo (n=8), 1 mg/kg (n=7) or 3 mg/kg (n=9) heme arginate infused intravenously 24 hours before surgery. A biopsy of the right ventricle was performed directly before aortic cross-clamping and after cross-clamp release. In addition, the right atrial appendage was partially removed for analysis. HO-1 protein and mRNA concentrations were measured in tissue samples and in peripheral blood mononuclear cells before to and up to 72 hours after surgery. No study medication-related adverse events occurred. A strong, dose-dependent effect on myocardial HO-1 mRNA levels was observed (right ventricle: 7.9±5.0 versus 88.6±49.1 versus 203.6±148.7; P=0.002 and right atrium: 10.8±8.8 versus 229.8±173.1 versus 392.7±195.7; P=0.001). This was paralleled by a profound increase of HO-1 protein concentration in atrial tissue (8401±3889 versus 28 585±10 692 versus 29 022±8583; P<0.001). Surgery and heme arginate infusion significantly increased HO-1 mRNA concentration in peripheral blood mononuclear cells ( P<0.001). HO-1 induction led to a significant increase of postoperative carboxyhemoglobin (1.7% versus 1.4%; P=0.041). No effect on plasma HO-1 protein levels could be detected. Conclusions- Myocardial HO-1 mRNA and protein can be dose-dependently induced by heme arginate. Protective effects of this therapeutic strategy should be evaluated in upcoming clinical trials. Clinical Trial Registration- URL: http://www.clinicaltrials.gov . Unique identifier: NCT02314780.

Plasma Heme Oxygenase-1 Levels and Carotid Atherosclerosis.

Background and Purpose- Heme oxygenase-1 (HO-1) catalyzes the oxidation of heme to generate carbon monoxide, biliverdin, and iron. Because these products have antiatherogenic properties, HO-1 may play a protective role against atherosclerosis. However, plasma HO-1 levels in patients with carotid atherosclerosis have not been reported. Methods- We investigated plasma HO-1 levels by ELISA in 136 subjects (age, 66±9 years) undergoing carotid ultrasonography. Results- Of the 136 study subjects, carotid plaque was found in 61 subjects (45%). Compared with 75 subjects without plaque, 61 with plaque were older and predominantly male ( P<0.05). Plasma HO-1 levels were higher in subjects with plaque than in those without plaque (median, 0.56 versus 0.44 ng/mL; P<0.05). The percentage of subjects with HO-1 level >0.50 ng/mL was higher in subjects with plaque than without plaque (66% versus 44%; P<0.025). In multivariate analysis, HO-1 level was a significant factor for carotid plaque independent of atherosclerotic risk factors. Odds ratio for plaque was 2.33 (95% CI, 1.15-4.75) for HO-1 level >0.50 ng/mL. Conclusions- Plasma HO-1 levels were high in subjects with carotid plaques, probably reflecting a protective response against carotid atherosclerosis.

Plasma Heme Oxygenase-1 Levels in Patients with Coronary and Peripheral Artery Diseases.

Aims Heme oxygenase-1 (HO-1) is an intracellular enzyme that catalyzes the oxidation of heme to generate CO, biliverdin, and iron. Since these products have antiatherogenic properties, HO-1 may play a protective role against the progression of atherosclerosis. However, plasma HO-1 levels in patients with atherosclerotic diseases, such as coronary artery disease (CAD) and peripheral artery disease (PAD), have not been clarified yet. Methods We investigated plasma HO-1 levels by ELISA in 410 consecutive patients undergoing elective coronary angiography who also had an ankle-brachial index (ABI) test for PAD screening. Results Of the 410 study patients, CAD was present in 225 patients (55%) (1-vessel (1-VD), n = 91; 2-vessel (2-VD), n = 66; 3-vessel disease (3-VD), n = 68). PAD (ABI < 0.9) was found in 36 (9%) patients. Plasma HO-1 levels did not differ between 225 patients with CAD and 185 without CAD (median 0.44 versus 0.35 ng/mL), but they were significantly lower in 36 patients with PAD than in 374 without PAD (0.27 versus 0.41 ng/mL, P < 0.02). After excluding the 36 patients with PAD, HO-1 levels were significantly higher in 192 patients with CAD than in 182 without CAD (0.45 versus 0.35 ng/mL, P < 0.05). HO-1 levels in 4 groups of CAD(−), 1-VD, 2-VD, and 3-VD were 0.35, 0.49, 0.44, and 0.44 ng/mL, respectively, and were highest in 1-VD (P < 0.05). In the multivariate analysis, HO-1 levels were inversely associated with PAD, whereas they were also associated with CAD. The odds ratios for PAD and CAD were 2.12 (95% CI = 1.03–4.37) and 0.65 (95% CI = 0.42–0.99) for the HO-1 level of <0.35 ng/mL, respectively. Conclusions Plasma HO-1 levels were found to be low in patients with PAD, in contrast to high levels in patients with CAD.

Whole-Blood Transcriptional Signatures Composed of Erythropoietic and NRF2-Regulated Genes Differ Between Cerebral Malaria and Severe Malarial Anemia.

Among the severe malaria syndromes, severe malarial anemia (SMA) is the most common, whereas cerebral malaria (CM) is the most lethal. However, the mechanisms that lead to CM and SMA are unclear. We compared transcriptomic profiles of whole blood obtained from Ugandan children with acute CM (n = 17) or SMA (n = 17) and community children without Plasmodium falciparum infection (n = 12) and determined the relationships among gene expression, hematological indices, and relevant plasma biomarkers. Both CM and SMA demonstrated predominantly upregulated enrichment of dendritic cell activation, inflammatory/Toll-like receptor/chemokines, and monocyte modules, but downregulated enrichment of lymphocyte modules. Nuclear factor, erythroid 2 like 2 (Nrf2)-regulated genes were overexpressed in children with SMA relative to CM, with the highest expression in children with both SMA and sickle cell disease (HbSS), corresponding with elevated plasma heme oxygenase-1 in this group. Erythroid and reticulocyte-specific signatures were markedly decreased in CM relative to SMA despite higher hemoglobin levels and appropriate increases in erythropoietin. Viral sensing/interferon-regulatory factor 2 module expression and plasma interferon-inducible protein-10/CXCL10 negatively correlated with reticulocyte-specific signatures. Compared with SMA, CM is associated with downregulation of Nrf2-related and erythropoiesis signatures by whole-blood transcriptomics. Future studies are needed to confirm these findings and assess pathways that may be amenable to interventions to ameliorate CM and SMA.

Associations Between Plasma Heme Oxygenase-1 Levels and Coronary and Peripheral Artery Disease

Associations Between Plasma Heme Oxygenase-1 Levels and Coronary and Peripheral Artery Disease

Dominant Role for Regulatory T Cells in Protecting Females Against Pulmonary Hypertension.

Pulmonary arterial hypertension (PH) is a life-threatening condition associated with immune dysregulation and abnormal regulatory T cell (Treg) activity, but it is currently unknown whether and how abnormal Treg function differentially affects males and females. To evaluate whether and how Treg deficiency differentially affects male and female rats in experimental PH. Male and female athymic rnu/rnu rats, lacking Tregs, were treated with the VEGFR2 (vascular endothelial growth factor receptor 2) inhibitor SU5416 or chronic hypoxia and evaluated for PH; some animals underwent Treg immune reconstitution before SU5416 administration. Plasma PGI2 (prostacyclin) levels were measured. Lung and right ventricles were assessed for the expression of the vasoprotective proteins COX-2 (cyclooxygenase 2), PTGIS (prostacyclin synthase), PDL-1 (programmed death ligand 1), and HO-1 (heme oxygenase 1). Inhibitors of these pathways were administered to athymic rats undergoing Treg immune reconstitution. Finally, human cardiac microvascular endothelial cells cocultured with Tregs were evaluated for COX-2, PDL-1, HO-1, and ER (estrogen receptor) expression, and culture supernatants were assayed for PGI2 and IL (interleukin)-10. SU5416-treatment and chronic hypoxia produced more severe PH in female than male athymic rats. Females were distinguished by greater pulmonary inflammation, augmented right ventricular fibrosis, lower plasma PGI2 levels, decreased lung COX-2, PTGIS, HO-1, and PDL-1 expression and reduced right ventricular PDL-1 levels. In both sexes, Treg immune reconstitution protected against PH development and raised levels of plasma PGI2 and cardiopulmonary COX-2, PTGIS, PDL-1, and HO-1. Inhibiting COX-2, HO-1, and PD-1 (programmed death 1)/PDL-1 pathways abrogated Treg protection. In vitro, human Tregs directly upregulated endothelial COX-2, PDL-1, HO-1, ERs and increased supernatant levels of PGI2 and IL-10. In 2 animal models of PH based on Treg deficiency, females developed more severe PH than males. The data suggest that females are especially reliant on the normal Treg function to counteract the effects of pulmonary vascular injury leading to PH.

Circulating Heme Oxygenase-1: Not a Predictor of Preeclampsia but Highly Expressed in Pregnant Women Who Subsequently Develop Severe Preeclampsia.

Preeclampsia is the major cause of maternal and fetal deaths worldwide. Circulating biomarker concentrations to predict preeclampsia must be determined. Therefore, the objective was to evaluate heme oxygenase-1 (HO-1) concentration in both plasma and urine samples from pregnant women before the development of preeclampsia and to identify a potential biomarker for preeclampsia development. We performed a case-control study nested in a prospective study cohort at University Hospital of the Ribeirao Preto Medical School, University of São Paulo (HCFMRP-USP), Ribeirao Preto, Brazil. Of 1400 pregnant women evaluated at 20–25 weeks of gestation, 460 delivered in hospitals outside our institution. Of 940 pregnant women who completed the protocol, 30 developed preeclampsia (cases, 14 cases of severe preeclampsia and 16 cases of mild preeclampsia). Healthy pregnant women (controls, n = 90) were randomly selected from the remaining 910 participants. HO-1 concentration was evaluated in plasma/urine samples by using a commercial enzyme-linked immunosorbent assay kit. We found similar HO-1 levels in the plasma and urine for case and control groups. In the subgrouped preeclampsia, lower plasma HO-1 levels were found in mild compared with severe preeclampsia. We conclude that plasma HO-1 levels were not altered at 20–25 weeks of gestation before the manifestation of preeclampsia symptoms. Pregnant women who subsequently develop severe preeclampsia show higher expression of HO-1. This may be indicative of important underlying pathophysiologic mechanisms that differentiate between mild and severe preeclampsia and may possibly be related to a higher prooxidative status even before the development of clinical symptoms.

Flavonoid-Rich Apple Improves Endothelial Function in Individuals at Risk for Cardiovascular Disease: A Randomized Controlled Clinical Trial.

The cardioprotective effects of apples are primarily attributed to flavonoids, found predominantly in the skin. This study aimed to determine if acute and/or chronic (4 weeks) ingestion of flavonoid-rich apples improves endothelial function, blood pressure (BP), and arterial stiffness in individuals at risk for cardiovascular diseases (CVD). In this randomized, controlled cross-over trial, acute and 4 week intake of apple with skin (high flavonoid apple, HFA) is compared to intake of apple flesh only (low flavonoid apple, LFA) in 30 participants. The primary outcome is endothelial function assessed using flow-mediated dilation (FMD) of the brachial artery, while main secondary outcomes are 24 h ambulatory BP and arterial stiffness. Other outcomes include fasting serum glucose and lipoprotein profile, plasma heme oxygenase-1 (Hmox-1), F2 -isoprostanes, flavonoid metabolites, and plasma and salivary nitrate (NO3- ) and nitrite (NO2- ) concentrations. Compared to LFA control, the HFA results in a significant increase in FMD acutely (0.8%, p<0.001) and after 4 weeks chronic intake (0.5%, p<0.001), and in plasma flavonoid metabolites (p<0.0001). Other outcomes are not altered significantly. A lower risk of CVD with higher apple consumption could be mediated by the beneficial effect of apple skin on endothelial function, both acutely and chronically.

Hemeoxygenase-1 as a Novel Driver in Ritonavir-Induced Insulin Resistance in HIV-1-Infected Patients.

Hemeoxygenase-1 (HO-1) has recently been identified as a major driver of metaflammation and obesity-related insulin resistance (IR). Drug-induced IR increases cardiovascular risk within the HIV-1-infected population receiving antiretroviral therapy (ART). We therefore investigated a possible role of HO-1 in ART-induced IR. Effects of HIV-1 protease inhibitor ritonavir and integrase inhibitor raltegravir (RAL) on expression levels of HO-1 and proinflammatory cytokines, including interleukin 1β (IL-1β), IL-6, IL-8, tumor necrosis factor-α (TNFα), chemokine (C-C motif) ligand 5 (CCL5), and monocyte chemotactic protein 1 (MCP-1), were studied in monocyte and hepatocyte cell lines. Plasma levels of HO-1 and inflammatory markers were measured in insulin-resistant and insulin-sensitive HIV-1-infected patients under ART and seronegative controls. We show that, in contrast to RAL, ritonavir treatment significantly increases mRNA expression levels of HO-1, IL-8, TNFα, CCL5, and MCP-1 in vitro in a dose-dependent manner. HO-1 plasma levels were significantly higher in insulin-resistant compared to insulin-sensitive patients on ritonavir-boosted ART (lopinavir/ritonavir group: 3.90 ± 1.15 vs 2.56 ± 1.07 ng/mL, P < 0.005 and darunavir/ritonavir group: 3.16 ± 1.37 vs 2.28 ± 1.23 U/mL, P < 0.05) and were correlated with expression levels of TNFα in individuals on ritonavir-boosted ART (lopinavir/ritonavir group: r = 0.108, P < 0.05 and darunavir/ritonavir group: r = 0.221, P < 0.05) but not in HIV-1-infected individuals receiving RAL or in seronegative controls. HIV-1-infected patients on stable ART are often faced with non-AIDS-related metabolic comorbidities, increasing their individual cardiovascular risk. Here, we provide insight into a novel mechanism of ritonavir-induced IR involving proinflammatory properties of HO-1. Our initial observations might also provide prognostic value in the future to identify patients at risk for the development type 2 diabetes mellitus.