Pro-inflammatory Phospholipid Arachidonic Acid/Eicosapentaenoic Acid Ratio of Dysmetabolic Severely Obese Women

Cancer and COVID-19: unravelling the immunological interplay with a review of promising therapies against severe SARS-CoV-2 for cancer patients

Cancer patients, due to their immunocompromised status, are at an increased risk for severe SARS-CoV-2 infection. Since severe SARS-CoV-2 infection causes multiple organ damage through IL-6-mediated inflammation while stimulating hypoxia, and malignancy promotes hypoxia-induced cellular metabolic alterations leading to cell death, we propose a mechanistic interplay between both conditions that results in an upregulation of IL-6 secretion resulting in enhanced cytokine production and systemic injury. Hypoxia mediated by both conditions results in cell necrosis, dysregulation of oxidative phosphorylation, and mitochondrial dysfunction. This produces free radicals and cytokines that result in systemic inflammatory injury. Hypoxia also catalyzes the breakdown of COX-1 and 2 resulting in bronchoconstriction and pulmonary edema, which further exacerbates tissue hypoxia. Given this disease model, therapeutic options are currently being studied against severe SARS-COV-2. In this study, we review several promising therapies against severe disease supported by clinical trial evidence-including Allocetra, monoclonal antibodies (Tixagevimab-Cilgavimab), peginterferon lambda, Baricitinib, Remdesivir, Sarilumab, Tocilizumab, Anakinra, Bevacizumab, exosomes, and mesenchymal stem cells. Due to the virus's rapid adaptive evolution and diverse symptomatic manifestation, the use of combination therapies offers a promising approach to decrease systemic injury. By investing in such targeted interventions, cases of severe SARS-CoV-2 should decrease along with its associated long-term sequelae and thereby allow cancer patients to resume their treatments.

Deregulation of Lipid Homeostasis: A Fa(c)t in the Development of Metabolic Diseases

Lipids are important molecules for human health. The quantity and quality of fats consumed in the diet have important effects on the modulation of both the natural biosynthesis and degradation of lipids. There is an important number of lipid-failed associated metabolic diseases and an increasing number of studies suggesting that certain types of lipids might be beneficial to the treatment of many metabolic diseases. The aim of the present work is to expose an overview of de novo biosynthesis, storage, and degradation of lipids in mammalian cells, as well as, to review the published data describing the beneficial effects of these processes and the potential of some dietary lipids to improve metabolic diseases.

Lipid mechanisms in hallmarks of cancer

Excess adiposity is a risk factor for several cancer types. This is likely due to complex mechanisms including alterations in the lipid milieu that plays a pivotal role in multiple aspects of carcinogenesis. Here we consider the direct role of lipids in regulating well-known hallmarks of cancer. Furthermore, we suggest that obesity-associated remodelling of membranes and organelles drives cancer cell proliferation and invasion. Identification of cancer-related lipid-mediated mechanisms amongst the broad metabolic disturbances due to excess adiposity is central to the identification of novel and more efficacious prevention and intervention strategies.

Metabolic indices of polyunsaturated fatty acids: current evidence, research controversies, and clinical utility

The n-3 and n-6 polyunsaturated fatty acids (PUFA) are among the most studied nutrients in human metabolism. In the past few decades, prospective studies and controlled trials have supported the view that the effects of these essential fatty acids are clinically relevant. PUFA profiles in different blood compartments are reflections of both diet and metabolism, and their levels may be related to disease risk. Despite widespread interest, there is no consensus regarding which biomarkers best reflect PUFA status in the body. The measurement of PUFA levels is not straight-forward, and a wide variety of indices have been used in clinical studies, producing conflicting results. A major source of heterogeneity among studies is associated with research design, sampling, and laboratory analyses. To date, the n-3 index, n-6/n-3 ratio, and arachidonic acid (AA)/eicosapentaenoic acid (EPA) ratio are the most promising biomarkers associated with PUFA metabolism. Although hotly debated, these indices may be considered at least markers, if not risk factors, for several diseases, especially cardiovascular events and brain disorders. Here, we summarize the most updated evidence of n-3 and n-6 PUFA effects on human health, reviewing current controversies on the aforementioned indices and whether they can be considered valuable predictors of clinical outcomes.

Obesity is a risk factor for acute promyelocytic leukemia: evidence from population and cross-sectional studies and correlation with FLT3 mutations and polyunsaturated fatty acid metabolism

Obesity correlates with hematologic malignancies including leukemias, but risk of specific leukemia subtypes like acute promyelocytic leukemia and underlying molecular mechanisms are poorly understood. We explored multiple datasets for correlation between leukemia, body mass index (BMI) and molecular features. In a population-based study (n=5.2 million), we correlated BMI with promyelocytic leukemia, and other acute myeloid, lymphoid or other leukemias. In cross-sectional studies, we tested BMI deviation in promyelocytic leukemia trial cohorts from that expected based on national surveys. We explored The Cancer Genome Atlas for transcriptional signatures and mutations enriched in promyelocytic leukemia and/or obesity, and confirmed a correlation between body mass and FLT3 mutations in promyelocytic leukemia cohorts by logistic regression. In the population-based study, hazard ratio per 5 kg/m² increase was: promyelocytic leukemia 1.44 (95%CI: 1.0-2.08), non-promyelocytic acute myeloid leukemias 1.17 (95%CI: 1.10-1.26), lymphoid leukemias 1.04 (95%CI: 1.0-1.09), other 1.10 (95%CI: 1.04-1.15). In cross-sectional studies, body mass deviated significantly from that expected (Italy: P<0.001; Spain: P=0.011; USA: P<0.001). Promyelocytic leukemia showed upregulation of polyunsaturated fatty acid metabolism genes. Odds of FLT3 mutations were higher in obese acute myeloid leukemias (odds ratio=2.4, P=0.007), whether promyelocytic or not, a correlation confirmed in the pooled promyelocytic leukemia cohorts (OR=1.22, 1.05-1.43 per 5 kg/m²). These results strengthen the evidence for obesity as a bona fide risk factor for myeloid leukemias, and in particular APL. FLT3 mutations and polyunsaturated fatty acid metabolism may play a previously under-appreciated role in obesity-associated leukemogenesis.

A high linoleic acid diet exacerbates metabolic responses and gut microbiota dysbiosis in obese rats with diabetes mellitus

Dietary polyunsaturated fatty acid (PUFA) levels may affect inflammatory responses and lipid metabolism.

High ApoD protein level in the round ligament fat depot of severely obese women is associated with an improved inflammatory profile

PURPOSE

Apolipoprotein D (ApoD) is a lipocalin participating in lipid transport. It binds to a variety of ligands, with a higher affinity for arachidonic acid, and is thought to have a diverse array of functions. We investigated a potential role for ApoD in insulin sensitivity, inflammation, and thrombosis-processes related to lipid metabolism-in severely obese women.

METHODS

We measured ApoD expression in a cohort of 44 severely obese women including dysmetabolic and non-dysmetabolic patients. Physical and metabolic characteristics of these women were determined from anthropometric measurements and blood samples. ApoD was quantified at the mRNA and protein levels in samples from three intra-abdominal adipose tissues (AT): omental, mesenteric and round ligament (RL).

RESULTS

ApoD protein levels were highly variable between AT of the same individual. High ApoD protein levels, particularly in the RL depot, were linked to lower plasma insulin levels (-40%, p = 0.015) and insulin resistance (-47%, p = 0.022), and increased insulin sensitivity (+10%, p = 0.008). Lower circulating pro-inflammatory PAI-1 (-39%, p = 0.001), and TNF-α (-19%, p = 0.030) levels were also correlated to high ApoD protein in the RL AT.

CONCLUSIONS

ApoD variability between AT was consistent with different accumulation efficiencies and/or metabolic functions according to the anatomic location of fat depots. Most statistically significant correlations implicated ApoD protein levels, in agreement with protein accumulation in target tissues. These correlations associated higher ApoD levels in fat depots with improved metabolic health in severely obese women.

The Omega-6:Omega-3 ratio: A critical appraisal and possible successor

The well-known health effects of the long-chain, marine omega-3 (n-3) fatty acids (FAs) has led to a growing interest in the prognostic value that blood levels of these FAs might have vis-à-vis cardiovascular and neurocognitive diseases. The measurement and expression of n-3 FA levels is not straight-forward, however, and a wide variety of means of expression of n-3 FA status have been used in research and clinical medicine. This has led to considerable confusion as to what "optimal" n-3 FA status is. The n-6:n-3 ratio has enjoyed relatively widespread use, but this apparently simple metric has both theoretical and practical difficulties that have contributed to misunderstandings in this field. Just as the once-popular polyunsaturated:saturated FA ratio has largely disappeared from the nutritional and medical literature, it may be time to replace the n-6:n-3 ratio with a newer metric that focuses on the primary deficiency in Western diets - the lack of eicosapentaenoic and docosahexaenoic acids (EPA and DHA). The Omega-3 Index (red blood cell EPA+DHA) has much to recommend it in this regard.

The potential contribution of dietary factors to breast cancer prevention

Breast cancer (BC), the leading cancer in women, is increasing in prevalence worldwide, concurrent with western metabolic epidemics, that is, obesity, metabolic syndrome, and diabetes, and shares major risk factors with these diseases. The corresponding potential for nutritional contributions toward BC prevention is reviewed and related to critical stages in the life cycle and their implications for carcinogenic and pathometabolic trajectories. BC initiation potentially involves diet-related pro-oxidative, inflammatory, and procarcinogenic processes, that interact through combined lipid/fatty acid peroxidation, estrogen metabolism, and related DNA-adduct/depurination/mutation formation. The pathometabolic trajectory is affected by high estrogen, insulin, and growth factor cascades and resultant accelerated proliferation/progression. Anthropometric risk factors - high birth weight, adult tallness, adiposity/BMI, and weight gain - are often reflective of these trends. A sex-based nutritional approach targets women's specific risk in western obesogenic environments, associated with increasing fatness, estrogen metabolism, n-6 : n-3 polyunsaturated fatty acid ratio, and n-6 polyunsaturated fatty acid conversion to proinflammatory/carcinogenic eicosanoids, and effects of timing of life events, for example, ages at menarche, full-term pregnancy, and menopause. Recent large-scale studies have confirmed the effectiveness of the evidence-based recommendations against BC risk, emphasizing low-energy density diets, highly nutritious plant-based regimes, physical activity, and body/abdominal adiposity management. Better understanding of dietary inter-relationships with BC, as applied to food intake, selection, combination, and processing/preparation, and recommended patterns, for example, Mediterranean, DASH, plant-based, low energy density, and low glycemic load, with high nutrient/phytonutrient density, would increase public motivation and authoritative support for early/timely prevention, optimally merging with other dietary/health goals, for lifelong BC prevention.

Alterations of specific lipid groups in serum of obese humans: a review

Obesity is a major contributor to the dysfunction of liver, cardiac, pulmonary, endocrine and reproductive system, as well as a component of metabolic syndrome. Although development of obesity-related disorders is associated with lipid abnormalities, most previous studies dealing with the problem in question were limited to routinely determined parameters, such as serum concentrations of triacylglycerols, total cholesterol, low-density and high-density lipoprotein cholesterol. Many authors postulated to extend the scope of analysed lipid compounds and to study obesity-related alterations in other, previously non-examined groups of lipids. Comprehensive quantitative, structural and functional analysis of specific lipid groups may result in identification of new obesity-related alterations. The review summarizes available evidence of obesity-related alterations in various groups of lipids and their impact on health status of obese subjects. Further, the role of diet and endogenous lipid synthesis in the development of serum lipid alterations is discussed, along with potential application of various lipid compounds as risk markers for obesity-related comorbidities.

Effects of Alpha-Lipoic Acid Supplementation on Plasma Adiponectin Levels and Some Metabolic Risk Factors in Patients with Schizophrenia

Adiponectin is an adipocyte-derived plasma protein with insulin-sensitizing and anti-inflammatory properties and is suggested to be a biomarker of metabolic disturbances. The aim of this study was to investigate the effects of alpha-lipoic acid (ALA) on plasma adiponectin and some metabolic risk factors in patients with schizophrenia. The plasma adipokine levels (adiponectin and leptin), routine biochemical and anthropometric parameters, markers of oxidative stress, and the serum phospholipid fatty acid profile in eighteen schizophrenic patients at baseline, in the middle, and at the end of a 3-month long supplementation period with ALA (500 mg daily) were determined. A significant increase in the plasma adiponectin concentrations, as well as a decrease in fasting glucose and aspartate aminotransferase activity (AST), was found. Baseline AST activity was independently correlated with the adiponectin concentrations. Our data show that ALA can improve plasma adiponectin levels and may play a potential role in the treatment of metabolic risk factor in patients with schizophrenia. Future randomized controlled trials are needed to confirm these preliminary investigations.

Anatomical distribution of primary amine oxidase activity in four adipose depots and plasma of severely obese women with or without a dysmetabolic profile

Semicarbazide-sensitive amine oxidase (SSAO), identical to primary amine oxidase or vascular adhesion protein-1, is a membrane enzyme that generates hydrogen peroxide. SSAO is highly expressed at the adipocyte surface, and its plasma levels increase with type 2 diabetes. Since visceral adipose tissue (AT) is more tightly associated with obesity complications than subcutaneous (SC) abdominal fat, we compared SSAO activity in plasma and 4 distinct AT locations in 48 severely obese women (body mass index (BMI), averaging 54 ± 11 kg/m²), with or without a dysmetabolic profile. Higher glucose and triacylglycerol levels vs lower high-density lipoprotein (HDL)-cholesterol characterized dysmetabolic women (DYS; n = 25) from non-dysmetabolic (NDYS; n = 23), age- and weight-matched subjects. SC, mesenteric (ME), omental (OM), and round ligament (RL) fat locations were collected during bariatric surgery. SSAO capacity to oxidize up to 1 mM benzylamine was determined in AT and plasma with radiometric and fluorimetric methods. Plasma SSAO was higher in the DYS group. SSAO activity was higher in fat than in plasma, when expressed as radiolabeled benzaldehyde per milligram of protein. In ATs from DYS women, protein content was 10 % higher, and basal hydrogen peroxide release lower than in NDYS subjects, except for RL location. The SSAO affinity towards benzylamine did not exhibit regional variation and was not altered by a dysmetabolic profile (K _m averaging 184 ± 7 μM; n = 183). Although radiometric and fluorimetric methods gave different estimates of oxidase activity, both indicated that AT SSAO activity did not vary according to anatomical location and/or metabolic status in severely obese women.

Gene expression in a rarely studied intraabdominal adipose depot, the round ligament, in severely obese women: A pilot study

Gene expression (qPCR) was compared in round ligament (RL), omental (OME) and mesenteric (MES) ATs from 48 severely obese women (BMI, 54±11 kg/m(2); 38±9 yrs). The mRNA levels of enzymes of lipid metabolism (LPL, HSL, and PDE-3B), cortisol production (11βHSD-1), adipogenesis (PPAR-γ1/2), thrombosis and inflammation (PAI-1, IL-6, TNF-α and adiponectin) were determined. AT-LPL mRNA was highest in RL. The highest PDE-3B and lowest PAI-1 mRNA levels were observed in RL and MES. The lowest IL-6 and TNF-α and the highest adiponectin and PPAR-g1/2 mRNA levels were found in RL AT. 11βHSD-1 was highest in RL and OME. A higher lipogenic and adipogenic, and lower pro-inflammatory and pro-thrombotic profiles of the RL suggest a lesser deleterious impact on obesity-related complications.

Fatty acids from fat cell lipolysis do not activate an inflammatory response but are stored as triacylglycerols in adipose tissue macrophages

AIMS/HYPOTHESIS

Activation of macrophages by fatty acids (FAs) is a potential mechanism linking obesity to adipose tissue (AT) inflammation and insulin resistance. Here, we investigated the effects of FAs released during adipocyte lipolysis on AT macrophages (ATMs).

METHODS

Human THP-1 macrophages were treated with media from human multipotent adipose-derived stem (hMADS) adipocytes stimulated with lipolytic drugs. Macrophages were also treated with mixtures of FAs and an inhibitor of Toll-like receptor 4, since this receptor is activated by saturated FAs. Levels of mRNA and the secretion of inflammation-related molecules were measured in macrophages. FA composition was determined in adipocytes, conditioned media and macrophages. The effect of chronic inhibition or acute activation of fat cell lipolysis on ATM response was investigated in vivo in mice.

RESULTS

Whereas palmitic acid alone activates THP-1, conditioned media from hMADS adipocyte lipolysis had no effect on IL, chemokine and cytokine gene expression, and secretion by macrophages. Mixtures of FAs representing de novo lipogenesis or habitual dietary conditions also had no effect. FAs derived from adipocyte lipolysis were taken up by macrophages and stored as triacylglycerol droplets. In vivo, chronic treatment with an antilipolytic drug did not modify gene expression and number of ATMs in mice with intact or defective Tlr4. Stimulation of adipocyte lipolysis increased storage of neutral lipids by macrophages without change in number and phenotype.

CONCLUSIONS/INTERPRETATION

Our data suggest that adipocyte lipolysis does not activate inflammatory pathways in ATMs, which instead may act as scavengers of FAs.

Unraveling the complex relationship triad between lipids, obesity, and inflammation

Obesity today stands at the intersection between inflammation and metabolic disorders causing an aberration of immune activity, and resulting in increased risk for diabetes, atherosclerosis, fatty liver, and pulmonary inflammation to name a few. Increases in mortality and morbidity in obesity related inflammation have initiated studies to explore different lipid mediated molecular pathways of attempting resolution that uncover newer therapeutic opportunities of anti-inflammatory components. Majorly the thromboxanes, prostaglandins, leukotrienes, lipoxins, and so forth form the group of lipid mediators influencing inflammation. Of special mention are the omega-6 and omega-3 fatty acids that regulate inflammatory mediators of interest in hepatocytes and adipocytes via the cyclooxygenase and lipoxygenase pathways. They also exhibit profound effects on eicosanoid production. The inflammatory cyclooxygenase pathway arising from arachidonic acid is a critical step in the progression of inflammatory responses. New oxygenated products of omega-3 metabolism, namely, resolvins and protectins, behave as endogenous mediators exhibiting powerful anti-inflammatory and immune-regulatory actions via the peroxisome proliferator-activated receptors (PPARs) and G protein coupled receptors (GPCRs). In this review we attempt to discuss the complex pathways and links between obesity and inflammation particularly in relation to different lipid mediators.

Anti-inflammatory and hypoglycemic efficacy of Poria cocos and Dioscorea opposita in prediabetes mellitus rats

Poria cocos (Fu Ling) and Dioscorea opposita (Chinese Yam) were suggested to have potential benefits in blood sugar control.

Relationship between acute phase proteins and serum fatty acid composition in morbidly obese patients

Background. Obesity is considered a low-grade inflammatory state and has been associated with increased acute phase proteins as well as changes in serum fatty acids. Few studies have assessed associations between acute phase proteins and serum fatty acids in morbidly obese patients. Objective. To investigate the relationship between acute phase proteins (C-Reactive Protein, Orosomucoid, and Albumin) and serum fatty acids in morbidly obese patients. Methods. Twenty-two morbidly obese patients were enrolled in this study. Biochemical and clinical data were obtained before bariatric surgery, and fatty acids measured in preoperative serum. Results. Orosomucoid was negatively correlated with lauric acid (P = 0.027) and eicosapentaenoic acid (EPA) (P = 0.037) and positively with arachidonic acid (AA) (P = 0.035), AA/EPA ratio (P = 0.005), and n-6/n-3 polyunsaturated fatty acids ratio (P = 0.035). C-Reactive Protein (CRP) was negatively correlated with lauric acid (P = 0.048), and both CRP and CRP/Albumin ratio were negatively correlated with margaric acid (P = 0.010, P = 0.008, resp.). Albumin was positively correlated with EPA (P = 0.027) and margaric acid (P = 0.008). Other correlations were not statistically significant. Conclusion. Our findings suggest that serum fatty acids are linked to acute phase proteins in morbidly obese patients.

Eicosanoids in metabolic syndrome

Chronic persistent inflammation plays a significant role in disease pathology of cancer, cardiovascular disease, and metabolic syndrome (MetS). MetS is a constellation of diseases that include obesity, diabetes, hypertension, dyslipidemia, hypertriglyceridemia, and hypercholesterolemia. Nonalcoholic fatty liver disease (NAFLD) is associated with many of the MetS diseases. These metabolic derangements trigger a persistent inflammatory cascade, which includes production of lipid autacoids (eicosanoids) that recruit immune cells to the site of injury and subsequent expression of cytokines and chemokines that amplify the inflammatory response. In acute inflammation, the transcellular synthesis of antiinflammatory eicosanoids resolve inflammation, while persistent activation of the autacoid-cytokine-chemokine cascade in metabolic disease leads to chronic inflammation and accompanying tissue pathology. Many drugs targeting the eicosanoid pathways have been shown to be effective in the treatment of MetS, suggesting a common linkage between inflammation, MetS and drug metabolism. The cross-talk between inflammation and MetS seems apparent because of the growing evidence linking immune cell activation and metabolic disorders such as insulin resistance, dyslipidemia, and hypertriglyceridemia. Thus modulation of lipid metabolism through either dietary adjustment or selective drugs may become a new paradigm in the treatment of metabolic disorders. This review focuses on the mechanisms linking eicosanoid metabolism to persistent inflammation and altered lipid and carbohydrate metabolism in MetS.