Metabolic interactions in asthma

Summary

Metabolomics can be used to explore altered metabolic pathways in asthma, giving insights into its pathophysiology. We aimed to review how metabolomics has been used to understand asthma by describing metabolic pathways under research and discussing clinical implications. The search was performed in PubMed, and studies published since 2000 using a metabolomics approach, were included. A total of 32 studies were analysed. Pathways related with cellular energy homeostasis, lipid metabolism and oxidative stress, immune and inflammatory processes and others were altered. Initial studies focused on biomarker discovery. But, metabolomics can be used to evaluate drug effects on specific pathways, to highlight pathways that can further develop in new targeted treatments and to identify differences according to asthma severity and phenotypes.

The Warburg effect: persistence of stem-cell metabolism in cancers as a failure of differentiation

Background

Two recent observations regarding the Warburg effect are that (i) the metabolism of stem cells is constitutive (aerobic) glycolysis while normal cellular differentiation involves a transition to oxidative phosphorylation and (ii) the degree of glucose uptake of a malignancy as imaged by 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is associated with histologic measures of tumor differentiation. Combining these observations, we hypothesized that the high levels of glucose uptake observed in poorly differentiated cancers may reflect persistence of the glycolytic metabolism of stem cells in malignant cells that fail to fully differentiate.

Patients and methods

Tumor glucose uptake was measured by FDG-PET in 552 patients with histologically diverse cancers. We used normal mixture modeling to explore FDG-PET standardized uptake value (SUV) distributions and tested for associations between glucose uptake and histological differentiation, risk of lymph node metastasis, and survival. Using RNA-seq data, we carried out pathway and transcription factor analyses to compare tumors with high and low levels of glucose uptake.

Results

We found that well-differentiated tumors had low FDG uptake, while moderately and poorly differentiated tumors had higher uptake. The distribution of SUV for each histology was bimodal, with a low peak around SUV 2-5 and a high peak at SUV 8-14. The cancers in the two modes were clinically distinct in terms of the risk of nodal metastases and death. Carbohydrate metabolism and the pentose-related pathway were elevated in the poorly differentiated/high SUV clusters. Embryonic stem cell-related signatures were activated in poorly differentiated/high SUV clusters.

Conclusions

Our findings support the hypothesis that the biological basis for the Warburg effect is a persistence of stem cell metabolism (i.e. aerobic glycolysis) in cancers as a failure to transition from glycolysis-utilizing undifferentiated cells to oxidative phosphorylation-utilizing differentiated cells. We found that cancers cluster along the differentiation pathway into two groups, utilizing either glycolysis or oxidative phosphorylation. Our results have implications for multiple areas of clinical oncology.

Epithelioid Hemangioendothelioma Of The Internal Jugular Vein

Ephitelioid Hemangioendothelioma (EHE) is a rare type of tumor with vascular and sarcomatous components. There's only another case published of an internal jugular vein (IJV) EHE. A case of a 50 years-old woman with a palpable and pulsatile mass on the left cervical area is reported. Doppler ultrasound and magnetic resonance imaging showed an IVJ' 4 cm mass. Cytology was inconclusive. Surgical treatment was therefore decided and during surgery a mass inside the left IJV, with local nonsuspicious lymph nodes, was confirmed. The mass was resected including a segmental resection of the IJV and one affected tributary vessel. Lymphadenectomy of the adjacent cervical levels was performed. Histologic examination depicted an EHE without metastatic lymph nodes. Tumor was staged as pT1bN0M0 and a multidisciplinary sarcoma group proposed surveillance. Patient remained well, without evidence of disease and without complications in a twenty-four months follow-up period.

Cardiotoxicity of environmental contaminant tributyltin involves myocyte oxidative stress and abnormal Ca2+ handling

Tributyltin (TBT) is an organotin environmental pollutant widely used as an agricultural and wood biocide and in antifouling paints. Countries began restricting TBT use in the 2000s, but their use continues in some agroindustrial processes. We studied the acute effect of TBT on cardiac function by analyzing myocardial contractility and Ca²⁺ handling. Cardiac contractility was evaluated in isolated papillary muscle and whole heart upon TBT exposure. Isolated ventricular myocytes were used to measure calcium (Ca²⁺) transients, sarcoplasmic reticulum (SR) Ca²⁺ content and SR Ca²⁺ leak (as Ca²⁺ sparks). Reactive oxygen species (ROS), as superoxide anion (O2^•-) was detected at intracellular and mitochondrial myocardium. TBT depressed cardiac contractility and relaxation in papillary muscle and intact whole heart. TBT increased cytosolic, mitochondrial ROS production and decreased mitochondrial membrane potential. In isolated cardiomyocytes TBT decreased both Ca²⁺ transients and SR Ca²⁺ content and increased diastolic SR Ca²⁺ leak. Decay of twitch and caffeine-induced Ca²⁺ transients were slowed by the presence of TBT. Dantrolene prevented and Tiron limited the reduction in SR Ca²⁺ content and transients. The environmental contaminant TBT causes cardiotoxicity within minutes, and may be considered hazardous to the mammalian heart. TBT acutely induced a negative inotropic effect in isolated papillary muscle and whole heart, increased arrhythmogenic SR Ca²⁺ leak leading to reduced SR Ca²⁺ content and reduced Ca²⁺ transients. TBT-induced myocardial ROS production, may destabilize the SR Ca²⁺ release channel RyR2 and reduce SR Ca²⁺ pump activity as key factors in the TBT-induced negative inotropic and lusitropic effects.

Abstract P1-18-05: Management of bone marrow involvement in advanced breast cancer: Retrospective multicenter cohort study

Background: Optimal management of bone marrow metastasis (BMM) in advanced breast cancer (ABC) remains unknown. Associated severe cytopenias often urge treatment, but they are also a challenging factor for delivering chemotherapy (CT). Since BMM in ABC is infrequent, available data are scarce.

Aim: Clinical and prognostic characterization of ABC patients with BMM and its management; evaluation of the effectiveness of treating BMM with more myelosuppressive CT regimen (that we hypothesized that could be more active in the BMM) Vs. less myelosuppressive regimen.

Methods: Retrospective cohort study of patients with pathological confirmation of BMM (positive myelogram or osteomedullary biopsy) between Jan'2010 and Dec'2016 in the two major Portuguese cancer centers. Patients with diagnosis of a second carcinoma or active hemato-oncological condition within 5 years before BMM were excluded. We considered the more myelosuppressive regimens those with > 5% risk of febrile neutropenia according to Truong et al 2015(1). Kaplan-Meier and log-rank methodology were used to estimate survival and Cox regression to identify the covariates with independent prognostic value. Statistical level of significance was 5%.

Results: We included 74 patients: 74% with disease stage I-III at presentation, 74% ductal and 12% lobular invasive carcinomas, 58% grade 2 and 27% grade 3, 80% hormone receptor + / HER2-, 4% HER2+ and 12% triple negative (TN). Median time from ABC diagnosis to BMM was 10 months (IQR 2-36), synchronous in 34%. At diagnosis of BMM, median age was 57 years-old (IQR 47-65), 57% were post-menopausal, 97% had bone metastasis, 50% had visceral metastasis, 53% performed ≥ 2 previous palliative systemic treatments and 53% were exposed to bisphosphonates. The most frequent immunohistochemistry change in BMM biopsy was the loss of progesterone receptor expression (37%). Bicytopenia (anemia/thrombocytopenia) was the trigger for BMM investigation in 69% of cases, with grade 3-4 anemia in 16% and grade 3-4 thrombocytopenia in 26%. Median survival after BMM diagnosis was 5 months (95% CI, 3-11); overall survival at 12 and 24 months were 35% (CI 26-48%) and 24% (CI 15-36%), respectively. First treatment after BMM was CT in 58% (median survival, 11 months) and endocrine therapy in 14% (median survival, 3 months). An anti-HER2 regimen was used in 4% and 22% did not receive any treatment after BMM. On multivariate analysis, TN subtype (HR 4.02, CI 1.46-11.01), thrombocytopenia (G0 reference; G1-2: HR 2.47, CI 1.11-5.56; G3-4: HR 4.89, CI 1.85-12.91) and ≥ 2 palliative systemic treatments (HR 2.77, CI 1.46-5.27) were associated with worse prognosis. Within those treated with CT, there was a trend for a deleterious survival effect of more myelosuppressive regimens (HR 2.19, CI 0.94-5.09; 5 months Vs. 14 months, n=31), after controlling for subtype, number of previous regimens and thrombocytopenia.

Conclusion: BMM was not a late event in ABC disease course and had worse prognosis in multi-treated patients, in TN subtype and in the presence of thrombocytopenia. No benefit was shown with the use of more myelosuppressive CT regimens.

(1)Truong J et al, Ann Oncol. 2016 Apr;27(4):608-18.

Citation Format: Martins-Branco D, Ferreira SC, Pereira I, André S, Varelas A, Leal C, Esteves S, Abreu MH, Sousa S, Moreira A, Brito M. Management of bone marrow involvement in advanced breast cancer: Retrospective multicenter cohort study [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-18-05.

Low cytomegalovirus seroprevalence in early multiple sclerosis: a case for the 'hygiene hypothesis'?

BACKGROUND AND PURPOSE

Cytomegalovirus (CMV) infection has recently been associated with a lower multiple sclerosis (MS) susceptibility, although it remains controversial whether it has a protective role or is merely an epiphenomenon related to westernization and early-life viral infections. We aimed to evaluate whether CMV serostatus may differ in patients with early MS as compared with patients with non-early MS, analyzing the putative association of this virus with MS clinical course and humoral immune responses against other herpesviruses.

METHODS

Multicentric analysis was undertaken of 310 patients with MS (early MS, disease duration ≤5 years, n = 127) and controls (n = 155), evaluating specific humoral responses to CMV, Epstein-Barr virus and human herpesvirus-6, as well as T-cell and natural killer (NK)-cell immunophenotypes.

RESULTS

Cytomegalovirus seroprevalence in early MS was lower than in non-early MS or controls (P < 0.01), being independently associated with disease duration (odds ratio, 1.04; 95% confidence interval, 1.01-1.08, P < 0.05). CMV+ patients with MS displayed increased proportions of differentiated T-cells (CD27-CD28-, CD57+, LILRB1+) and NKG2C+ NK-cells, which were associated with a lower disability in early MS (P < 0.05). CMV+ patients with early MS had an age-related decline in serum anti-EBNA-1 antibodies (P < 0.01), but no CMV-related differences in anti-human herpesvirus-6 humoral responses.

CONCLUSIONS

Low CMV seroprevalence was observed in patients with early MS. Modification of MS risk attributed to CMV might be related to the induction of differentiated T-cell and NK-cell subsets and/or modulation of Epstein-Barr virus-specific immune responses at early stages of the disease.

Mechanisms of exercise-induced bronchoconstriction in athletes: Current perspectives and future challenges

The evidence of exercise-induced bronchoconstriction (EIB) without asthma (EIBw_A ) occurring in athletes led to speculate about different endotypes inducing respiratory symptoms within athletes. Classical postulated mechanisms for bronchial obstruction in this population include the osmotic and the thermal hypotheses. More recently, the presence of epithelial injury and inflammation in the airways of athletes was demonstrated. In addition, neuronal activation has been suggested as a potential modulator of bronchoconstriction. Investigation of these emerging mechanisms is of major importance as EIB is a significant problem for both recreational and competitive athletes and is the most common chronic condition among Olympic athletes, with obvious implications for their competing performance, health and quality of life. Hereby, we summarize the latest achievements in this area and identify the current gaps of knowledge so that future research heads toward better defining the etiologic factors and mechanisms involved in development of EIB in elite athletes as well as essential aspects to ultimately propose preventive and therapeutic measures.

Vaginal lichen sclerosus: report of two cases

BACKGROUND

Lichen sclerosus most commonly affects the genital area. Contrarily to lichen planus, the involvement of the oral or vaginal mucosa is rare. Only four cases of vaginal lichen sclerosus have been described in the literature.

CASE REPORT

The authors report two cases of postmenopausal women with a history of vulvar pruritus and burning. Both presented with lesions of the vaginal mucosa compatible with lichen sclerosus, and genital prolapse. Vaginal biopsies confirmed the diagnosis. Initial treatment with topical clobetasol was effective in one of the patients, but in the other patient line therapy with pimecrolimus, triamcinolone, and retinoids was needed.

CONCLUSION

Vaginal lichen sclerosus may be underdiagnosed and genital prolapse may favour the development of vaginal lesions.

Brain Metabolic Abnormalities in Schizophrenia Patients

Introduction

Main schizophrenia symptoms result from abnormalities in brain function, such as hypofrontality and structural deficits on the prefrontal-thalamic-cerebellar circuit, as shown in brain imaging studies in first-episode SCZ patients. Whether metabolic alterations may be underlying these events is being studied thoroughly.

Objectives/aims

To assess brain metabolic disturbances in first episode and/or drug-naïve SCZ patients.

Methods

We conducted a literature review through Pubmed search for MeSH: schizophrenia, metabolism, glucose, insulin, brain. Controlled studies on first episode and/or drug-naïve SCZ patients were included.

Results

Lower metabolic activity in the frontal regions of the brain is associated to an increase in norepinephrine transmission and decrease in dopaminergic transmission with reduced dopamine efflux in the frontal cortex. This seems to lead to cellular changes resulting in resulting lower blood flow and glucose demand. Molecular analysis of postmortem SCZ patients’ brains has indicated alterations in glucose metabolism and insulin signalling pathways, showing evidence for prefrontal cortex decreased expression of glucose metabolism, namely glycolytic enzymes such as glyceraldehyde 3-phosphate dehydrogenase, hexokinase, phosphoglycerate mutase, enolase and pyruvate kinase and decreased levels and phosphorylation of the insulin receptor and insulin signalling proteins AKT1 and GSK3β. Significantly elevated glucose concentrations in cerebrospinal fluid were observed in SCZ patients, but with no serum levels differences. A SCZ brain specific increased glucose could be explained by preferential utilization of lactate, predominantly produced by astrocytes, over glucose as an energy substrate.

Conclusions

Abnormalities in brain glucose metabolism and insulin signalling seem to appear in early stages of SCZ, suggesting a role in SCZ onset and pathophysiology.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Peripheric Metabolic Abnormalities in Schizophrenia Patients

Introduction

Schizophrenia (SCZ) is frequently associated with metabolic symptoms including dyslipidaemia, hyperinsulinemia, type 2 diabetes and obesity. In fact, SCZ patients have been reported to present higher prevalence of these conditions than general population, commonly associated to second generation antipsychotic therapy. Recent studies, however, have demonstrated that peripheral metabolic disturbances can appear at disease onset or drug-naïve patients.

Objectives/aims

To assess metabolic disturbances in first episode and/or drug-naïve SCZ patients.

Methods

We conducted a literature review through Pubmed search for MeSH: schizophrenia, metabolism, glucose, insulin. Controlled studies on first episode and/or drug-naïve SCZ patients were included.

Results

Several studies showed no change in SCZ patients’ fasting blood glucose, while others found increased glucose levels and impaired glucose tolerance in SCZ patients compared to healthy controls in several recent studies. Hyperinsulinemia and insulin resistance have also been identified in antipsychotic-naïve SCZ patients and it has been suggested that early onset patients are more likely to present insulin resistance. In addition, there's evidence of increased circulating levels of chromogranin A, pancreatic polypeptide, prolactin, cortisol, progesterone, thus emphasising that multiple components of the hypothalamic-pituitary-adrenal-gonadal axis may be affected in SCZ. These elevations were associated to normal glycaemia suggesting there may be insulin intolerance during early stages of SCZ, requiring an increased secretion from pancreatic Bcells to maintain normal glucose levels.

Conclusions

Recent studies of first onset and/or drug-free schizophrenia patients have shown impaired fasting glucose tolerance, hyperinsulinemia and insulin intolerance, suggesting that metabolic abnormalities may play a role in SCZ onset and pathophysiology.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Intrinsic reproductive isolating mechanisms in the maintenance of a hybrid zone between ecologically divergent subspecies

Understanding factors involved in maintaining stable hybrid zones is important for predicting the ultimate fate of the interacting taxa, but the relative importance of mechanisms such as ecological selection and intrinsic reproductive isolation remains unclear. Most studies of reproductive isolation in hybrid zones have focused either on zones with strongly bimodal patterns in genotype or phenotype frequencies, with relatively strong isolation, or unimodal zones with relatively weak isolation, whereas less is known about more intermediate classes of hybrid zone. Here, we utilize a hybrid zone of this intermediate type occurring between northern and southern subspecies of Atlantic killifish, Fundulus heteroclitus, to identify isolating mechanisms playing a role in maintaining this type of zone. The two subspecies differ in environmental tolerance, and we found some evidence of microhabitat preference between subspecies within a small tidal creek at the centre of the hybrid zone. There was also an association between sex, mitochondrial genotype and habitat within this creek. Fertilization success did not differ between consubspecific and heterosubspecific crosses, but hatching success was significantly lower for crosses involving southern males and northern females, and crosses between southern females and northern males had altered developmental rates. Southern females and northern males showed patterns consistent with positive assortative mating. Together, these results indicate a role for a combination of factors including assortative mating and/or early hybrid inviability in the maintenance of this hybrid zone and suggest that hybrid zones with intermediate levels of reproductive isolation are likely to be maintained by multiple interacting isolating mechanisms.

Adherence to the Mediterranean diet in children: Is it associated with economic cost?

Highlights

The average diet cost was 4.58€ (SD = 1.24) in 6-12 years-old children.Diet cost calculations were based on food prices information from 2011.Most children reported medium (69.1%) or high (4.6%) adherence to Mediterranean diet.Higher adherence to Mediterranean diet was associated with higher diet cost.

Objective

To assess how the diet cost is associated with socio-demographic factors and adherence to Mediterranean diet in children.

Methods

Data were obtained from a community-based survey of children selected from public elementary schools in Portugal. Of a total of 586 children attending these schools, 464 (6-12 years), were studied. Dietary intake was assessed by a 24 hour recall and the adherence to Mediterranean diet was evaluated through the KIDMED index. The cost of the diet was calculated based on the collection of food prices of a national leader supermarket, and expressed as Total Daily Cost (TDC) and Total Daily Cost-Adjusted for Energy (TDEC). Anthropometric measures were taken and socio-demographic data were gathered from a questionnaire filled by parents. Logistic regression was used to quantify the association between diet cost, socio-demographics and adherence to Mediterranean diet.

Results

The average TDC was 4.58€ (SD = 1.24). Most children (69.1%) reported medium adherence to Mediterranean diet, and 4.6% rated the higher score. TDC was higher for children with highest adherence to Mediterranean diet, compared to those with lowest adherence [TDC: OR = 5.70 (95% CI 1.53, 21.33), p for trend = 0.001; TDEC: OR = 2.83 (95% CI 0.89, 8.96, p for trend 0.018)]. No meaningful variation in the diet cost with age and parental education was observed.

Conclusion

Higher adherence to Mediterranean diet was associated with higher diet cost in children.