Metabolic Syndrome and its Correlates among Hypertensive Patients in Abuja, North Central Nigeria.

BACKGROUND: Metabolic syndrome is a constellation of abnormalities which includes central obesity, dyslipidaemia, elevated blood pressure and hyperglycemia. Hypertension, (which is a very common component of metabolic syndrome), and diabetes mellitus, are independently associated. Also, studies examining metabolic syndrome inAbuja, a city with affluence-driven lifestyle, are not available. This study aimed to investigate the prevalence of metabolic syndrome among hypertensive patients in Abuja, Nigeria, as well as to examine the associations between metabolic syndrome and certain factors in that cohort of hypertensive patients. METHODS: This was a retrospective study that used data from hypertensive patients who attended clinic over a period of five years. Eight hundred and fifty-eight, (858-combined), case files of pre-treated, (previously known hypertensive patients) and newly diagnosed hypertensive participants were used for the study. The student t-tests were used to compare continuous variables, while Chi-square (χ2) tests were used for relationship between qualitative variables. The likelihood ratio test was employed to further confirm the statistical significance of certain independent variables relating with metabolic syndrome. A P-value of < 0.05 was considered statistically significant. RESULTS: The mean ages were 48.70±12.18, 49.19±11.06 and 48.2±13.3 years for combined group, the pre-treated and the newly-diagnosed groups respectively. The pre-treated, group consists of those previously known hypertensive patients, while the new group consists of those who were newly diagnosed hypertensive patients and were treatment naïve. The prevalence of metabolic syndrome in this study was 45.5% in the combined group, 47.23% in the pre-treated group and 37.3% in the newly diagnosed group. The commonest component of metabolic syndrome was reduced high density lipoprotein cholesterol, HDL-C. CONCLUSION: Metabolic syndrome is prevalent among hypertensive patients in Abuja, Nigeria. Some correlates of metabolic syndrome include; elevated BMI, truncal obesity, elevated total cholesterol, the use of thiazide diuretics and beta blockers as antihypertensives.

CONTEXTE: Le syndrome métabolique est une constellation d'anomalies qui comprend l'obésité centrale, la dyslipidémie, l'élévation de la pression artérielle et l'hyperglycémie. L'hypertension, qui est un composant très courant du syndrome métabolique, et le diabète sucré sont indépendamment associés. De plus, des études examinant le syndrome métabolique à Abuja, une ville au mode de vie axé sur l'aisance, ne sont pas disponibles. Cette étude visait à enquêter sur la prévalence du syndrome métabolique parmi les patients hypertendus à Abuja, au Nigeria, ainsi qu'à examiner les associations entre le syndrome métabolique et certains facteurs dans cette cohorte de patients hypertendus. MÉTHODES: Il s'agissait d'une étude rétrospective utilisant des données de patients hypertendus ayant fréquenté la clinique sur une période de cinq ans. Huit cent cinquante-huit (858 - combinés) dossiers de cas de patients hypertendus préalablement traités (patients hypertendus connus) et nouvellement diagnostiqués ont été utilisés pour l'étude. Les tests t de Student ont été utilisés pour comparer les variables continues, tandis que les tests du chi-carré (χ2) ont été utilisés pour examiner la relation entre les variables qualitatives. Le test du rapport de vraisemblance a été utilisé pour confirmer davantage la signification statistique de certaines variables indépendantes liées au syndrome métabolique. Une valeur P < 0,05 était considérée comme statistiquement significative. RÉSULTATS: Les âges moyens étaient de 48,70 ± 12,18, 49,19 ± 11,06 et 48,21 ± 13,3 ans pour le groupe combiné, le groupe prétraité et le groupe nouvellement diagnostiqué, respectivement. La prévalence du syndrome métabolique dans cette étude était de 45,5% dans le groupe combiné, 47,23% dans le groupe prétraité et 37,3% dans le groupe nouvellement diagnostiqué. Le composant le plus courant du syndrome métabolique était une diminution du cholestérol lipoprotéique de haute densité, le HDL-C. CONCLUSION: Le syndrome métabolique est prévalent parmi les patients hypertendus àAbuja, au Nigeria. Certains corrélats du syndrome métabolique comprennent un IMC élevé, une obésité tronculaire, une augmentation du cholestérol total, l'utilisation de diurétiques thiazidiques et de bêta-bloquants comme antihypertenseurs. Mots-clés: Syndrome métabolique, corrélats, patients hypertendus, Abuja Nigeria.

Precision Medicine Approach for Cardiometabolic Risk Factors in Therapeutic Apheresis.

Lipoprotein apheresis (LA) is currently the most powerful intervention possible to reach a maximal reduction of lipids in patients with familial hypercholesterolemia and lipoprotein(a) hyperlipidemia. Although LA is an invasive method, it has few side effects and the best results in preventing further major cardiovascular events. It has been suggested that the highly significant reduction of cardiovascular complications in patients with severe lipid disorders achieved by LA is mediated not only by the potent reduction of lipid levels but also by the removal of other proinflammatory and proatherogenic factors. Here we performed a comprehensive proteomic analysis of patients on LA treatment using intra-individually a set of differently sized apheresis filters with the INUSpheresis system. This study revealed that proteomic analysis correlates well with routine clinical chemistry in these patients. The method is eminently suited to discover new biomarkers and risk factors for cardiovascular disease in these patients. Different filters achieve reduction and removal of proatherogenic proteins in different quantities. This includes not only apolipoproteins, C-reactive protein, fibrinogen, and plasminogen but also proteins like complement factor B (CFAB), protein AMBP, afamin, and the low affinity immunoglobulin gamma Fc region receptor III-A (FcγRIIIa) among others that have been described as atherosclerosis and metabolic vascular diseases promoting factors. We therefore conclude that future trials should be designed to develop an individualized therapy approach for patients on LA based on their metabolic and vascular risk profile. Furthermore, the power of such cascade filter treatment protocols may improve the prevention of cardiometabolic disease and its complications.

The transCampus Metabolic Training Programme Explores the Link of SARS-CoV-2 Virus to Metabolic Disease.

Currently, we are experiencing a true pandemic of a communicable disease by the virus SARS-CoV-2 holding the whole world firmly in its grasp. Amazingly and unfortunately, this virus uses a metabolic and endocrine pathway via ACE2 to enter our cells causing damage and disease. Our international research training programme funded by the German Research Foundation has a clear mission to train the best students wherever they may come from to learn to tackle the enormous challenges of diabetes and its complications for our society. A modern training programme in diabetes and metabolism does not only involve a thorough understanding of classical physiology, biology and clinical diabetology but has to bring together an interdisciplinary team. With the arrival of the coronavirus pandemic, this prestigious and unique metabolic training programme is facing new challenges but also new opportunities. The consortium of the training programme has recognized early on the need for a guidance and for practical recommendations to cope with the COVID-19 pandemic for the community of patients with metabolic disease, obesity and diabetes. This involves the optimal management from surgical obesity programmes to medications and insulin replacement. We also established a global registry analyzing the dimension and role of metabolic disease including new onset diabetes potentially triggered by the virus. We have involved experts of infectious disease and virology to our faculty with this metabolic training programme to offer the full breadth and scope of expertise needed to meet these scientific challenges. We have all learned that this pandemic does not respect or heed any national borders and that we have to work together as a global community. We believe that this transCampus metabolic training programme provides a prime example how an international team of established experts in the field of metabolism can work together with students from all over the world to address a new pandemic.

DHEA inhibits acute microglia-mediated inflammation through activation of the TrkA-Akt1/2-CREB-Jmjd3 pathway.

Dehydroepiandrosterone (DHEA) is the most abundant circulating steroid hormone in humans, produced by the adrenals, the gonads and the brain. DHEA was previously shown to bind to the nerve growth factor receptor, tropomyosin-related kinase A (TrkA), and to thereby exert neuroprotective effects. Here we show that DHEA reduces microglia-mediated inflammation in an acute lipopolysaccharide-induced neuro-inflammation model in mice and in cultured microglia in vitro. DHEA regulates microglial inflammatory responses through phosphorylation of TrkA and subsequent activation of a pathway involving Akt1/Akt2 and cAMP response element-binding protein. The latter induces the expression of the histone 3 lysine 27 (H3K27) demethylase Jumonji d3 (Jmjd3), which thereby controls the expression of inflammation-related genes and microglial polarization. Together, our data indicate that DHEA-activated TrkA signaling is a potent regulator of microglia-mediated inflammation in a Jmjd3-dependent manner, thereby providing the platform for potential future therapeutic interventions in neuro-inflammatory pathologies.

Inherited anxiety-related parent-infant dyads alter LHPA activity.

The pathogenesis of post-traumatic stress disorder (PTSD) is incompletely understood. We hypothesize that disruptions in mother-child relations may be a key contributor to development of PTSD. A normal and healthy separation-individuation process requires adaptations of self- and interactive contingency in both the mother and her child, especially in early childhood development. Anxious mothers are prone to overprotection, which may hinder the individuation process in their children. We examined long-term stress hormones and other stress markers in subjects three generations removed from the Holocaust, to assess the long-term consequences of inherited behavioral and physiological responses to prior stress and trauma. Jewish subjects who recalled overprotective parental behavior had higher hairsteroid-concentrations and dampened limbic-hypothalamic-pituitary-adrenal (LHPA) axis reactivity compared to German and Russian-German subjects with overprotective parents. We suggest that altered LHPA axis activity in maternally overprotected Jewish subjects may indicate a transmitted pathomechanism of "frustrated individuation" resulting from cross-generational anti-Semitic experiences. Thus measurements of hairsteroid-concentrations and parenting practices may have clinical value for diagnosis of PTSD. We propose that this apparent inherited adaptivity of LHPA axis activity could promote higher individual stress resistance, albeit with risk of an allostatic overload.

Urinary Lipidomics: evidence for multiple sources and sexual dimorphism in healthy individuals.

Urinary lipidomics may add new valuable biomarkers to the diagnostic armamentarium for early detection of metabolic and kidney diseases. Sources and composition of urinary lipids in healthy individuals, however, have not been investigated in detail. Shotgun lipidomics was used to quantify lipidomic profiles in native urine samples from 16 individuals (eight men, eight women) collected in five fractions over 24 h. All probands were comprehensively characterized by urinary and clinical indices. The mean total urinary lipid concentration per sample was 0.84 µM in men and 1.03 µM in women. We observed significant intra- and interindividual variations of lipid concentrations over time, but failed to detect a clear circadian pattern. Based on quantity and subclass composition it seems very unlikely that plasma serves as major source for the urinary lipidome. Considering lipid metabolites occurring in at least 20% of all samples 38 lipid species from 7 lipid classes were identified. Four phosphatidylserine and one phosphatidylethanolamine ether species (PE-O 36:5) were detectable in almost all urine samples. Sexual dimorphism has been found mainly for phosphatidylcholines and phosphatidylethanolamines. In men and in women urinary lipid species were highly correlated with urinary creatinine and albumin excretion, reflecting glomerular filtration and tubular transport processes. In women, however, lipid species deriving from urinary cells and cellular constituents of the lower genitourinary tract considerably contributed to the urinary lipidome. In conclusion, our study revealed the potential of urinary lipidomics but also the complexity of methodological challenges which have to be overcome for its implementation as a routine diagnostic tool for renal, urological and metabolic diseases.

The PHF21B gene is associated with major depression and modulates the stress response.

Major depressive disorder (MDD) affects around 350 million people worldwide; however, the underlying genetic basis remains largely unknown. In this study, we took into account that MDD is a gene-environment disorder, in which stress is a critical component, and used whole-genome screening of functional variants to investigate the 'missing heritability' in MDD. Genome-wide association studies (GWAS) using single- and multi-locus linear mixed-effect models were performed in a Los Angeles Mexican-American cohort (196 controls, 203 MDD) and in a replication European-ancestry cohort (499 controls, 473 MDD). Our analyses took into consideration the stress levels in the control populations. The Mexican-American controls, comprised primarily of recent immigrants, had high levels of stress due to acculturation issues and the European-ancestry controls with high stress levels were given higher weights in our analysis. We identified 44 common and rare functional variants associated with mild to moderate MDD in the Mexican-American cohort (genome-wide false discovery rate, FDR, <0.05), and their pathway analysis revealed that the three top overrepresented Gene Ontology (GO) processes were innate immune response, glutamate receptor signaling and detection of chemical stimulus in smell sensory perception. Rare variant analysis replicated the association of the PHF21B gene in the ethnically unrelated European-ancestry cohort. The TRPM2 gene, previously implicated in mood disorders, may also be considered replicated by our analyses. Whole-genome sequencing analyses of a subset of the cohorts revealed that European-ancestry individuals have a significantly reduced (50%) number of single nucleotide variants compared with Mexican-American individuals, and for this reason the role of rare variants may vary across populations. PHF21b variants contribute significantly to differences in the levels of expression of this gene in several brain areas, including the hippocampus. Furthermore, using an animal model of stress, we found that Phf21b hippocampal gene expression is significantly decreased in animals resilient to chronic restraint stress when compared with non-chronically stressed animals. Together, our results reveal that including stress level data enables the identification of novel rare functional variants associated with MDD.

Adrenal medullary dysfunction as a feature of obesity.

BACKGROUND AND OBJECTIVE: Although there is strong evidence linking obesity with increased sympathoneural activity, involvement of the adrenal medulla is less clear. We therefore investigated adrenal medullary function under fasting and feeding conditions in normal weight (NW, n=33), overweight (OW, n=28) and obese (OB, n=36) adults (59% women). SUBJECTS AND METHODS: Ninety-seven healthy adults participated in a cross-sectional study with recruitment stratified according to BMI. Plasma for catecholamines and metanephrines was sampled in the fasting state, at 30-min intervals during a 120-min glucose tolerance test and during an euglycaemic-hyperinsulinaemic clamp (40 mU m-2 min-1 insulin dose). Body composition was determined by leg-to-leg bioelectrical impedance analysis. RESULTS: Obese subjects had the lowest fasting plasma concentrations of epinephrine (NW: 0.17, 95% confidence interval (CI): 0.14-0.20 nmol l-1; OW: 0.16, 95% CI: 0.12-0.19 nmol l-1; OB: 0.11, 95% CI: 0.08-0.13 nmol l-1; P=0.018) and metanephrine (NW: 0.17, 95% CI: 0.15-0.19 nmol l-1; OW: 0.15, 95% CI: 0.13-0.16 nmol l-1; OB: 0.13, 95% CI: 0.12-0.15 nmol l-1; P=0.022), the latter reflecting adrenal medullary store size. Fasting plasma epinephrine (r=-0.437; P<0.001) and metanephrine (r=-0.477; P<0.001) concentrations were additionally inversely correlated with whole-body fat percentage. Suppression of epinephrine secretion in response to carbohydrate ingestion was significantly blunted in overweight and obese subjects compared with the normal weight subjects (Pinteraction=0.045). Most of the variance in basal epinephrine was related to whole-body fat percentage (ß=-0.389, 95% CI: -0.09 to -0.69; P=0.012) that explained the lower concentrations of epinephrine and metanephrine in women than men. CONCLUSIONS: We provide evidence that adrenomedullary dysfunction is a characteristic feature of obesity that involves both reduced adrenal secretion of epinephrine and size of adrenal medullary epinephrine stores.

Genetic overlap between type 2 diabetes and depression in Swedish and Danish twin registries.

A bidirectional association between type 2 diabetes (T2DM) and depression has been consistently reported. Depression is associated with worse biomedical outcomes and increased mortality. The mechanisms underlying the association of T2DM with depression remain unclear. One possible question we can address is the extent to which the co-occurrence of diabetes and depression is due to correlated genetic and/or environmental risk factors. In this study, we performed structural equation model fitting to population-level data from the Swedish (n=68 606) and Danish (n=95 403) twin registries. The primary outcomes were clinical diagnosis of T2DM and depression using national hospital discharge registries. The phenotypic correlation between T2DM and depression is modest in both samples. In the Swedish sample, unique environmental effects explain a greater proportion of the covariance in males, whereas the association is primarily attributed to genetic effects in females. In the Danish sample, genetic effects account for the majority of the covariance in both males and females. Qualitative genetic sex differences are observed in both samples. We believe this is the first study to demonstrate significant genetic overlap between T2DM and depression.

The effects of stress on brain and adrenal stem cells.

The brain and adrenal are critical control centers that maintain body homeostasis under basal and stress conditions, and orchestrate the body's response to stress. It is noteworthy that patients with stress-related disorders exhibit increased vulnerability to mental illness, even years after the stress experience, which is able to generate long-term changes in the brain's architecture and function. High levels of glucocorticoids produced by the adrenal cortex of the stressed subject reduce neurogenesis, which contributes to the development of depression. In support of the brain-adrenal connection in stress, many (but not all) depressed patients have alterations in the components of the limbic-hypothalamic-pituitary-adrenal (LHPA) axis, with enlarged adrenal cortex and increased glucocorticoid levels. Other psychiatric disorders, such as post-traumatic stress disorder, bipolar disorder and depression, are also associated with abnormalities in hippocampal volume and hippocampal function. In addition, hippocampal lesions impair the regulation of the LHPA axis in stress response. Our knowledge of the functional connection between stress, brain function and adrenal has been further expanded by two recent, independent papers that elucidate the effects of stress on brain and adrenal stem cells, showing similarities in the way that the progenitor populations of these organs behave under stress, and shedding more light into the potential cellular and molecular mechanisms involved in the adaptation of tissues to stress.

Anti-inflammatory properties of bone morphogenetic protein 4 in human adipocytes.

BACKGROUND: Obesity is characterized by increased adipocyte number and size as well as white adipose tissue (WAT) inflammation, which is fundamental for the development of insulin resistance and type-2 diabetes. These processes, regulated by various endocrine, paracrine and autocrine factors, are extensively studied with the hope to interfere and to inhibit weight gain and related complications in obese patients. Recent data suggest an important role of bone morphogenic protein 4 (BMP4) in the regulation of adipogenesis and development of obesity. BMP4 is a growth factor of the transforming growth factor-ß superfamily. Initially, BMPs were identified as inducers of ectopic bone formation. It is now apparent, however, that these proteins have different pleiotropic developmental actions and including playing a role in white adipogenesis. METHODS AND RESULTS: Here, we demonstrate that the expression of BMP4 in human WAT is negatively correlated to body mass index and to the expression of pro-inflammatory cytokines. In vitro, BMP4 expression in cultured human adipocytes is upregulated after induction of differentiation. Cells treated with exogenous BMP4 increased peroxisome proliferator-activated receptor γ (PPARγ) expression and significantly reduced the expression of pro-inflammatory cytokines including tumor necrosis factor α (TNF-α) and monocyte chemoattractant protein 1. TNF-α treatment of fully differentiated adipocytes resulted in downregulation of the expression of adipogenic genes and elevated expression of pro-inflammatory cytokines. Exogenous BMP4 addition significantly reduced the negative effect of TNF-α on the expression profile of adipocytes. Finally, treatment of human adipocytes with exogenous BMP4 reduced the adipocytes' chemoattractant potential and the migration of monocytes toward adipocyte-conditioned medium. CONCLUSIONS: These results indicate that BMP4 is an important anti-inflammatory molecule, which may act through PPARγ and reduces TNF-α-mediated pro-inflammatory cytokine production in human adipocytes. Through its anti-inflammatory potential, BMP4 may serve as a protective factor for inflammation-related diseases such as insulin-tolerance or type-2 diabetes.

Pharmacogenomics in type 2 diabetes: oral antidiabetic drugs.

Type 2 diabetes mellitus (T2DM) is a fast progressing disease reaching pandemic proportions. T2DM is specifically harmful because of its severe secondary complications. In the course of the disease, most patients require treatment with oral antidiabetic drugs (OADs), for which a relatively large number of different options are available. The growing number of individuals affected by T2DM as well as marked interindividual differences in the response to treatment call for individualized therapeutic regimens that can maximize treatment efficacy and thus reduce side effects and costs. A large number of genetic polymorphisms have been described affecting the response to treatment with OADs; in this review, we summarize the most recent advances in this area of research. Extensive evidence exists for polymorphisms affecting pharmacokinetics and pharmacodynamics of biguanides and sulfonylureas. Data on incretin-based medications as well as the new class of sodium/glucose cotransporter 2 (SGLT2) inhibitors are just starting to emerge. With diabetes being a known comorbidity of several psychiatric disorders, we also review genetic polymorphisms possibly responsible for a common treatment response in both conditions. For all drug classes reviewed here, large prospective trials are necessary in order to consolidate the existing evidence and derive treatment schemes based on individual genetic traits.

Valproic acid enhances neuronal differentiation of sympathoadrenal progenitor cells.

The antiepileptic drug valproic acid (VPA) has been shown to influence the neural differentiation and neurite outgrowth of neural stem cells. Sympathoadrenal progenitor cells share properties with neural stem cells and are considered a potential cell source in the treatment of neurodegenerative diseases. The present study therefore aims at modulating the neural differentiation potential of these cells by treatment with the histone deacetylase inhibitor VPA. We studied the epigenetic effects of VPA in two culture conditions: suspension conditions aimed to expand adrenomedullary sympathoadrenal progenitors within free-floating chromospheres and adherent cell cultures optimized to derive neurons. Treatment of chromospheres with VPA may launch neuronal differentiation mechanisms and improve their neurogenic potential upon transplantation. However, also transplantation of differentiated functional neurons could be beneficial. Treating chromospheres for 7 days with clinically relevant concentrations of VPA (2 mm) revealed a decrease of neural progenitor markers Nestin, Notch2 and Sox10. Furthermore, VPA initiated catecholaminergic neuronal differentiation indicated by upregulation of the neuronal marker ß-III-tubulin, the dopaminergic transcription factor Pitx3 and the catecholaminergic enzymes TH and GTPCH. In adherent neural differentiation conditions, VPA treatment improved the differentiation of sympathoadrenal progenitor cells into catecholaminergic neurons with significantly elevated levels of nor- and epinephrine. In conclusion, similar to neural stem cells, VPA launches differentiation mechanisms in sympathoadrenal progenitor cells that result in increased generation of functional neurons. Thus, data from this study will be relevant to the potential use of chromaffin progenitors in transplantation therapies of neurodegenerative diseases.

Serum and Plasma Levels of Vascular Endothelial Growth Factors in Relation to Quality of Glucose Control, Biomarkers of Inflammation, and Diabetic Nephropathy.

Levels of vascular endothelial growth factors (VEGF) are regulated in a complex network of adipokines, glucose control, and low grade inflammation together with activated platelets, leucocytes, and endothelial dysfunction. Increased levels of VEGF are associated with enhanced angiogenesis and impaired repair mechanisms of vascular lesions in endorgans. Little is known about the interaction of systemic VEGF levels with quality of diabetes control, biomarkers of inflammation, and diabetic nephropathy. Moreover, it is unclear, whether serum and plasma VEGF levels are similarly suited to reflect risk associated with VEGF.In this case control study, we analyzed these parameters in serum and plasma of age and sex matched controls without diabetes (n=99) and type 2 diabetes (n=302). Serum VEGF-A was significantly increased in patients with T2DM while plasma levels were in the same range as for controls. Individual levels varied in a wide range. Serum levels were 4.9 times higher in controls and 7.3 times higher in T2DM as compared to plasma levels. T2DM was associated with significantly higher levels of hsCRP, ALAT, and albumin/creatinine ratio. When calculated for tertiles of HbA1c, we observed a highly significant increase from tertile one to the upper tertile for serum VEGF-A but not for plasma VEGF-A. Correlation analysis revealed a significant relationship between VEGF-A, HbA1c, inflammation, and diabetic nephropathy. Our results indicate that increased VEGF-A levels in T2DM significantly depend on quality of HbA1c control. Serum levels of VEGF-A, with a strong contribution of platelet derived VEGF, better reflect the glycemic burden than plasma levels of VEGF-A. Mechanistic studies are needed to explore links to inflammation and diabetic nephropathy.

STAT3-Ser/Hes3 Signaling: A New Molecular Component of the Neuroendocrine System?

The endocrine system involves communication among different tissues in distinct organs, including the pancreas and components of the Hypothalamic-Pituitary-Adrenal Axis. The molecular mechanisms underlying these complex interactions are a subject of intense study as they may hold clues for the progression and treatment of a variety of metabolic and degenerative diseases. A plethora of signaling pathways, activated by hormones and other endocrine factors have been implicated in this communication. Recent advances in the stem cell field introduce a new level of complexity: adult progenitor cells appear to utilize distinct signaling pathways than the more mature cells in the tissue they co-reside. It is therefore important to elucidate the signal transduction requirements of adult progenitor cells in addition to those of mature cells. Recent evidence suggests that a common non-canonical signaling pathway regulates adult progenitors in several different tissues, rendering it as a potentially valuable starting point to explore their biology. The STAT3-Ser/Hes3 Signaling Axis was first identified as a major regulator of neural stem cells and, subsequently, cancer stem cells. In the endocrine/neuroendocrine system, this pathway operates on several levels, regulating other types of plastic cells: (a) it regulates pancreatic islet cell function and insulin release; (b) insulin in turn activates the pathway in broadly distributed neural progenitors and possibly also hypothalamic tanycytes, cells with important roles in the control of the adrenal gland; (c) adrenal progenitors themselves operate this pathway. The STAT3-Ser/Hes3 Signaling Axis therefore deserves additional research in the context of endocrinology.

Interaction of epoxyeicosatrienoic acids and adipocyte fatty acid-binding protein in the modulation of cardiomyocyte contractility.

BACKGROUND: Adipocyte fatty acid-binding protein (FABP4) is a member of a highly conserved family of cytosolic proteins that bind with high affinity to hydrophobic ligands, such as saturated and unsaturated long-chain fatty acids and eicosanoids. Recent evidence has supported a novel role for FABP4 in linking obesity with metabolic and cardiovascular disorders. In this context, we identified FABP4 as a main bioactive factor released from human adipose tissue that directly suppresses heart contraction in vitro. As FABP4 is known to be a transport protein, it cannot be excluded that lipid ligands are involved in the cardiodepressant effect as well, acting in an additional and/or synergistic way. OBJECTIVE: We investigated a possible involvement of lipid ligands in the negative inotropic effect of adipocyte factors in vitro. RESULTS: We verified that blocking the CYP epoxygenase pathway in adipocytes attenuates the inhibitory effect of adipocyte-conditioned medium (AM) on isolated adult rat cardiomyocytes, thus suggesting the participation of epoxyeicosatrienoic acids (EETs) in the cardiodepressant activity. Analysis of AM for EETs revealed the presence of 5,6-, 8,9-, 11,12- and 14,15-EET, whereas 5,6-EET represented about 45% of the total EET concentration in AM. Incubation of isolated cardiomyocytes with EETs in similar concentrations as found in AM showed that 5,6-EET directly suppresses cardiomyocyte contractility. Furthermore, after addition of 5,6-EET to FABP4, the negative inotropic effect of FABP4 was strongly potentiated in a concentration-dependent manner. CONCLUSIONS: These data suggest that adipocytes release 5,6-EET and FABP4 into the extracellular medium and that the interaction of these factors modulates cardiac function. Therefore elevated levels of FABP4 and 5,6-EET in obese patients may contribute to the development of heart dysfunction in these subjects.

Changes in morphology and function of adrenal cortex in mice fed a high-fat diet.

BACKGROUND/OBJECTIVES: Obesity is a major risk factor for the development of type 2 diabetes and other debilitating diseases. Obesity and diabetes are intimately linked with altered levels of adrenal steroids. Elevated levels of these hormones induce insulin resistance and cause cardiovascular diseases. The mechanisms underlying obesity-related alterations in adrenal steroids are still not well understood. Here, we investigated how diet-induced obesity affects the morphology and function of the mouse adrenal cortex. METHODS: We fed animals either a high-fat diet (HFD) or a normal diet (60% kcal from fat or 10% kcal from fat, respectively) for 18 weeks. We then assessed various aspects of adrenal gland morphology and function, as well as basal plasma concentrations of steroid hormones and ACTH. RESULTS: We show that adrenal glands of mice fed a HFD release more corticosterone and aldosterone, resulting in higher plasma levels. This increase is driven by adrenal cortical hyperplasia, and by increased expression of multiple genes involved in steroidogenesis. We demonstrate that diet-induced obesity elevates Sonic hedgehog signaling in Gli1-positive progenitors, which populate the adrenal capsule and give rise to the steroidogenic cells of the adrenal cortex. Feeding animals with a HFD depletes Gli1-positive progenitors, as the adrenal cortex expands. CONCLUSIONS: This work provides insight into how diet-induced obesity changes the biology of the adrenal gland. The association of these changes with increased Shh signaling suggests possible therapeutic strategies for obesity-related steroid hormone dysfunction.

Crosstalk Between Glycoxidative Modification of Low-Density Lipoprotein, Angiotensin II-Sensitization, and Adrenocortical Aldosterone Release.

Low-density lipoprotein (LDL) is considered to be a risk factor for atherosclerosis. In the presence of hyperglycemia, LDL undergoes glycoxidative modification and this glycoxidized (glycox) LDL promotes atherosclerosis in type 2 diabetic (T2D) individuals. Moreover, because of its cholesterol content, LDL contributes to aldosterone biosynthesis, which is modulated by angiotensin II (AngII) and has been implicated in cardiovascular complications of T2D. However, the molecular mechanism of the crosstalk between glycoxLDL, AngII, and aldosterone has not been explained clearly. Therefore, this study has been aimed to investigate the impact of in vitro modified glycoxLDL on aldosterone release in an AngII-sensitized adrenocortical carcinoma cell line (NCI H295R). Native LDL (natLDL), isolated from healthy volunteers by sequential density gradient ultracentrifugation, was subjected to d-glucose (200 mmol/l), for glycoxidative modification, at 37 °C for 6 days. The AngII-sensitized H295R cells were treated with natLDL and glycoxLDL for 24 h and the supernatant was used for aldosterone measurement. The treated cells were utilized for protein isolation and mRNA quantification. Compared to natLDL, glycoxLDL produced a significantly greater effect on aldosterone release from AngII-sensitized cells. The treatment with specific pharmacological inhibitors suggests that modified LDL recruits ERK1/2 and janus kinase-2 for transcriptional regulation of aldosterone synthase. Moreover, glycoxLDL modulates aldosterone release via cAMP-dependent protein kinase A (PKA) pathway. However, glycoxLDL induces ERK phosphorylation independent of PKA activation and this novel mechanism could be targeted for therapeutic trials. In conclusion, this in vitro study emphasizes a possible causal relationship between LDL glycoxidative modification, AngII-sensitization, and adrenocortical steroid hormone release.