[Endocrinological Effects of Lithium: Pathophysiological Mechanisms and Clinical Implications]. / Efectos endocrinológicos del litio: Mecanismos fisiopatológicos e implicancias clínicas.

Lithium carbonate has a narrow therapeutic range capable of producing various adverse effects; despite this fact, it is used as first-line therapy in patients with bipolar disorder (BD) thanks to its high effectiveness. Among its adverse events are several conditions at the endocrine level, such as hypothyroidism, hyperthyroidism, hypercalcemia, hyperparathyroidism, and nephrogenic diabetes insipidus. The adherence to current guidelines for monitoring those events is low. The objective of this review is to provide insight into the pathophysiological mechanisms of the endocrine effects of lithium and give recommendations based on the current literature for the monitoring and treatment of these conditions.

Progressive 11ß-Hydroxysteroid Dehydrogenase Type 2 Insufficiency as Kidney Function Declines.

BACKGROUND: It has been postulated that chronic kidney disease (CKD) is a state of relative 11ß-hydroxysteroid dehydrogenase type 2 (11ßHSD2) insufficiency, resulting in increased cortisol-mediated mineralocorticoid receptor (MR) activation. We hypothesized that relative 11ßHSD2 insufficiency manifests across a wide spectrum of progressively declining kidney function, including within the normal range. METHODS: Adult participants were recruited at two academic centers. A discovery cohort (n=500) enrolled individuals with estimated glomerular filtration rate (eGFR) ranging from normal to CKD stage 5, in whom serum cortisol-to-cortisone (F/E) was measured as a biomarker of 11ßHSD2 activity. A validation cohort (n=101) enrolled only individuals with normal kidney function (eGFR ≥ 60 mL/min/1.73 m2) in whom 11ßHSD2 activity was assessed via serum F/E and 11-hydroxy-to-11-keto androgen (11OH/K) ratios following multiple maneuvers: oral sodium suppression test (OSST), dexamethasone suppression test (DST), and ACTH-stimulation test (ACTHstim). RESULTS: In the discovery cohort, lower eGFR was associated with higher F/E (P-trend<0.001). Similarly, in the validation cohort, with normal eGFR, an inverse association between eGFR and both F/E and 11OH/K ratios was observed (P-trend<0.01), which persisted following DST (P-trend<0.001) and ACTHstim (P-trend< 0.05). The fractional excretion of potassium, a marker of renal MR activity, was higher with higher F/E (P-trend < 0.01) and with lower eGFR (P-trend<0.0001). CONCLUSIONS: A continuum of declining 11ßHSD2 activity was observed with progressively lower eGFR in individuals spanning a wide spectrum of kidney function, including those with apparently normal kidney function. These findings implicate cortisol-mediated MR activation in the pathophysiology of hypertension and cardiovascular disease in CKD.

Adipose Tissue Dysfunction and the Role of Adipocyte-Derived Extracellular Vesicles in Obesity and Metabolic Syndrome.

Obesity is a major public health issue that is associated with metabolic diseases including diabetes mellitus type 2 and metabolic syndrome. This pathology leads to detrimental cardiovascular health and secondary effects, such as lipotoxicity, inflammation, and oxidative stress. Recently, extracellular vesicles (EVs) have been highlighted as novel players participating in human physiology and pathophysiology. In obesity, adipose tissue is related to the active shedding of adipocyte-derived extracellular vesicles (AdEVs). The current review explores and highlights the role of AdEVs and their cargo in obesity and metabolic syndrome. AdEVs are proposed to play an important role in obesity and its comorbidities. AdEVs are biological nanoparticles mainly shed by visceral and subcutaneous adipose tissue, acting in physiological and pathophysiological conditions, and also carrying different cargo biomolecules, such as RNA, microRNA (miRNA), proteins, and lipids, among others. RNA and miRNA have local and systemic effects affecting gene expression in target cell types via paracrine and endocrine actions. State of the art analyses identified some miRNAs, such as miR-222, miR-23b, miR-4429, miR-148b, and miR-4269, that could potentially affect cell pathways involved in obesity-related comorbidities, such as chronic inflammation and fibrosis. Similarly, AdEVs-proteins (RBP4, perilipin-A, FABP, mimecan, TGFBI) and AdEVs-lipids (sphingolipids) have been linked to the obesity pathophysiology. The current knowledge about AdEVs along with further research would support and reveal novel pathways, potential biomarkers, and therapeutic options in obesity.

The role of sex hormones in aldosterone biosynthesis and their potential impact on its mineralocorticoid receptor.

Blood pressure (BP) regulation is a complex process involving various hormones, including aldosterone and its mineralocorticoid receptor. Mineralocorticoid receptor is expressed in several tissues, including the kidney, and plays a crucial role in regulating BP by controlling the sodium and water balance. During different stages of life, hormonal changes can affect mineralocorticoid receptor activity and aldosterone levels, leading to changes in BP. Increasing evidence suggests that sex steroids modulate aldosterone levels. Estrogens, particularly estradiol, mediate aldosterone biosynthesis by activating classical estrogen receptors and the G protein-coupled receptor. Progesterone acts as an anti-mineralocorticoid by inhibiting the binding of aldosterone to the mineralocorticoid receptor. Moreover, progesterone inhibits aldosterone synthase enzymes. The effect of testosterone on aldosterone synthesis is still a subject of debate. However, certain studies show that testosterone downregulates the mRNA levels of aldosterone synthase, leading to decreased plasma aldosterone levels.

Low Cortisone as a Novel Predictor of the Low-Renin Phenotype.

A large proportion of patients with low-renin hypertension (LRH) correspond to primary aldosteronism (PA). However, some of these subjects have low to normal aldosterone. Since low renin is driven by excessive mineralocorticoids or glucocorticoids acting on mineralocorticoid receptors (MRs), we hypothesize that a low-cortisone condition, associated classically with 11ßHSD2 deficiency, is a proxy of chronic MR activation by cortisol, which can also lead to low renin, elevated blood pressure, and renal and vascular alterations. Objective: To evaluate low cortisone as a predictor of low renin activity and its association with parameters of kidney and vascular damage. Methods: A cross-sectional study was carried out in 206 adult subjects. The subjects were classified according to low plasma renin activity (<1 ng/mL × hours) and low cortisone (<25th percentile). Results: Plasma renin activity was associated with aldosterone (r = 0.36; P < .001) and cortisone (r = 0.22; P = .001). A binary logistic regression analysis showed that serum cortisone per ug/dL increase predicted the low-renin phenotype (OR 0.4, 95% CI 0.21-0.78). The receiver operating characteristic curves for cortisone showed an area under the curve of 0.6 to discriminate subjects with low renin activity from controls. The low-cortisone subjects showed higher albuminuria and PAI-1 and lower sodium excretion. The association study also showed that urinary cortisone was correlated with blood pressure and serum potassium (P < .05). Conclusion: This is the first study showing that low cortisone is a predictor of a low-renin condition. Low cortisone also predicted surrogate markers of vascular and renal damage. Since the aldosterone to renin ratio is used in the screening of PA, low cortisone values should be considered additionally to avoid false positives in the aldosterone-renin ratio calculation.

Familial hyperaldosteronism: an European Reference Network on Rare Endocrine Conditions clinical practice guideline.

We describe herein the European Reference Network on Rare Endocrine Conditions clinical practice guideline on diagnosis and management of familial forms of hyperaldosteronism. The guideline panel consisted of 10 experts in primary aldosteronism, endocrine hypertension, paediatric endocrinology, and cardiology as well as a methodologist. A systematic literature search was conducted, and because of the rarity of the condition, most recommendations were based on expert opinion and small patient series. The guideline includes a brief description of the genetics and molecular pathophysiology associated with each condition, the patients to be screened, and how to screen. Diagnostic and treatment approaches for patients with genetically determined diagnosis are presented. The recommendations apply to patients with genetically proven familial hyperaldosteronism and not to families with more than one case of primary aldosteronism without demonstration of a responsible pathogenic variant.

ThyroidPrint®: clinical utility for indeterminate thyroid cytology.

Molecular testing contributes to improving the diagnosis of indeterminate thyroid nodules (ITNs). ThyroidPrint® is a ten-gene classifier aimed to rule out malignancy in ITN. Post-validation studies are necessary to determine the real-world clinical benefit of ThyroidPrint® in patients with ITN. A single-center, prospective, noninterventional clinical utility study was performed, analyzing the impact of ThyroidPrint® in the physicians' clinical decisions for ITN. Demographics, nodule characteristics, benign call rates (BCRs), and surgical outcomes were measured. Histopathological data were collected from surgical biopsies of resected nodules. Of 1272 fine-needle aspirations, 109 (8.6%) were Bethesda III and 135 (10.6%) were Bethesda IV. Molecular testing was performed in 155 of 244 ITN (63.5%), of which 104 were classified as benign (BCR of 67.1%). After a median follow-up of 15 months, 103 of 104 (99.0%) patients with a benign ThyroidPrint® remained under surveillance and one patient underwent surgery which was a follicular adenoma. Surgery was performed in all 51 patients with a suspicious for malignancy as per ThyroidPrint® result and in 56 patients who did not undergo testing, with a rate of malignancy of 70.6% and 32.1%, respectively. A higher BCR was observed in follicular lesion of undetermined significance (87%) compared to atypia of undetermined significance (58%) (P < 0.05). False-positive cases included four benign follicular nodules and six follicular and four oncocytic adenomas. Our results show that, physicians chose active surveillance instead of diagnostic surgery in all patients with a benign ThyroidPrint® result, reducing the need for diagnostic surgery in 67% of patients with preoperative diagnosis of ITN.

Clinical, biochemical, and miRNA profile of subjects with positive screening of primary aldosteronism and nonclassic apparent mineralocorticoid excess.

Primary aldosteronism (PA) and nonclassic apparent mineralocorticoid excess (NCAME) have been recognized as endocrine-related conditions having a broad clinical-biochemical spectrum, spanning from normotension to severe arterial hypertension (AHT). However, the coexistence of both phenotypes have not been reported to date. AIM: To identify and characterize clinical and biochemical parameters of subjects with both PA and NCAME conditions (NCAME&PA) and study the miRNA cargo in their urinary extracellular vesicles as potential biomarkers for this novel condition. METHODS: We performed a cross-sectional study of 206 Chilean adult subjects from a primary care cohort. We measured blood pressure (BP), cortisol (F), cortisone (E), aldosterone, plasma renin activity (PRA), microalbuminuria (MAC), plasma NGAL, MMP9, fractional-potassium-excretion (FEK). Subjects were classified as NCAME&PA, PA, NCAME, essential hypertensives (EH), or healthy controls (CTL). EV-miRNAs were quantified by Taqman-qPCR. RESULTS: We found that 30.6% subjects had an abnormal endocrine phenotype: NCAME&PA (6.8%), PA (11.2%) or NCAME (12.6%), and the prevalence of AHT was 92.9%, 82.6%, and 65%, respectively. NCAME&PA subjects had both lower cortisone (p < 0.05) and lower PRA (p < 0.0001), higher FEK (p = 0.02) and higher MAC (p = 0.01) than EH or CTL. NCAME&PA subjects had also higher NGAL levels than CTL and PA (p < 0.05). Exosome miR-192, miR-133a and miR-21 expression decreased with phenotype severity and correlated with BP and PRA (p < 0.05). CONCLUSION: We identified adult subjects with a combined condition of NCAME and PA associated with higher BP, increased renal and endothelial damage markers than control and EH. Additionally, we observed a differential expression of a specific miRNAs, suggesting a potential role of these miRNAs associated to this novel combined phenotype.

Cortisol resistance in the degu (Octodon degus).

Cortisol resistance has also been reported in the degu, Octodon degus, a New World hystricomorph endemic to central Chile. The degu is used as a model for studies of stress and diurnal rhythms, parental behaviour and female masculinization. Another New World hystricomorph, the guinea pig, also exhibits glucocorticoid resistance, a result of amino acid sequences that differ from other mammalian glucocorticoid receptors (GR). Mutations in the ligand-binding domain of the human GR have been identified in familial or sporadic generalised cortisol resistance as have variants in the guinea pig. To address the possibility that the high levels of cortisol observed in the degu are a result of the same or similar sequence variations observed in the guinea pig GR, we have cloned, expressed and characterised the ligand-binding domain (LBD) of the degu GR. Somewhat unexpectedly, neither the amino acids nor the region involved in the resistance observed in the guinea pig GR are relevant in the degu GR. The relative resistance to cortisol observed in the degu GR is conferred by the substitution of two isoleucine residues, which are highly conserved in the GR across species, with a valine doublet. These amino acids lie in the region between helices 5 and 6 of the GR LBD, a region known to be important in determining the affinity of ligand-binding in steroid receptors.

Aldosterone and renin concentrations were abnormally elevated in a cohort of normotensive pregnant women.

BACKGROUND: During pregnancy, the renin-angiotensin-aldosterone system (RAAS) undergoes major changes to preserve normal blood pressure (BP) and placental blood flow and to ensure a good pregnancy outcome. Abnormal aldosterone-renin metabolism is a risk factor for arterial hypertension and cardiovascular risk, but its association with pathological conditions in pregnancy remains unknown. Moreover, potential biomarkers associated with these pathological conditions should be identified. AIM: To study a cohort of normotensive pregnant women according to their serum aldosterone and plasma renin levels and assay their small extracellular vesicles (sEVs) and a specific protein cargo (LCN2, AT1R). METHODS: A cohort of 54 normotensive pregnant women at term gestation was included. We determined the BP, serum aldosterone, and plasma renin concentrations. In a subgroup, we isolated their plasma sEVs and semiquantitated two EV proteins (AT1R and LCN2). RESULTS: We set a normal range of aldosterone and renin based on the interquartile range. We identified 5/54 (9%) pregnant women with elevated aldosterone and low renin levels and 5/54 (9%) other pregnant women with low aldosterone and elevated renin levels. No differences were found in sEV-LCN2 or sEV-AT1R. CONCLUSION: We found that 18% of normotensive pregnant women had either high aldosterone or high renin levels, suggesting a subclinical status similar to primary aldosteronism or hyperreninemia, respectively. Both could evolve to pathological conditions by affecting the maternal vascular and renal physiology and further the BP. sEVs and their specific cargo should be further studied to clarify their role as potential biomarkers of RAAS alterations in pregnant women.

The impact of the micronutrient iodine in health and diseases.

Adequate iodine nutrition is crucial for all mammals by playing his starring role as a component of thyroid hormones, which are key regulators of cellular processes for life such as differentiation, growth, function, and metabolism. Deficiency or excess of iodine in the diet are worldwide highly frequent conditions that are responsible of health problems like hypothyroidism, hypothyroxinemia, goiter, thyroiditis, hyperthyroidism, and autoimmune thyroid diseases among others. The incorporation of iodine in salt or other nutrients resolved the consequences of severe iodine deficiency like goiter, cretinism. However, this strategy in several countries led to other ailments like Hashimoto autoimmune thyroiditis, hyperthyroidism, and hypothyroidism. The goal of this review is to analyze and discuss the different aspects of iodine nutrition for human health comprising its biological role through thyroid hormones, pathogen control, and the regulation of the intestinal microbiota.

Primary Aldosteronism, Aldosterone, and Extracellular Vesicles.

Primary aldosteronism (PA) is an endocrine related condition leading to arterial hypertension due to inappropriately high and unregulated aldosterone concentration. Recently, a broad spectrum of PA has been recognized, which brings new challenges associated with early identification of this condition that affect renal epithelial and extrarenal tissues. Reports have shown the potential role of extracellular vesicles (EVs) and EV cargo as novel and complementary biomarkers in diagnosis and prognosis of PA. In vivo and in vitro studies have identified specific EV surface antigens, EV-proteins, and EV microRNAs that can be useful to develop novel diagnostic algorithms to detect, confirm, or follow up the PA. Moreover, the study of EVs in the field of PA provides further insight in the pathophysiological mechanism of the PA disease.

Plasminogen Activator Inhibitor-1 and Adiponectin Are Associated With Metabolic Syndrome Components.

BACKGROUND: We aimed to study the associations of adipocytokines, endothelial damage markers, and high-sensitivity C-reactive protein (hs-CRP) with metabolic syndrome (MetS) components. METHODS: This cross-sectional study included 202 subjects categorized into MetS and No-MetS according to Harmonizing Adult Treatment Panel III. RESULTS: Subjects with MetS showed higher levels of proinflammatory molecules but significantly lower adiponectin levels than subjects with No-MetS. Among the studied adipocytokines, plasminogen activator inhibitor-1 (PAI-1) and adiponectin showed the strongest associations with most MetS components. PAI-1 was associated with MetS (odds ratio (OR) 1.107 (1.065-1.151), P < 0.0001), whereas adiponectin was inversely associated with MetS (OR 0.710 (0.610-0.825), P < 0.0001). Following adjustment by sex, age, body mass index, and 24-hour urinary sodium excretion in a multivariate analysis, the association of PAI-1 (OR 1.090 (1.044-1.137), P < 0.0001) and adiponectin (OR 0.634 (0.519-0.775), P < 0.0001) with MetS remained significant. Multivariate analyses supported a model in which systolic blood pressure (BP) could be predicted by PAI-1, hs-CRP, and matrix metalloproteinase 2 (R2 = 0.125; P = 0.04); diastolic BP (R2 = 0.218; P = 0.0001) and glucose (R2 = 0.074; P = 0.0001) could be predicted by PAI-1; waist circumference could be predicted by PAI-1 and hs-CRP (R2 = 0.28; P = 0.016). Receiver operating characteristic curve analysis showed that a PAI-1 concentration had the best sensitivity and specificity for discriminating subjects with MetS. CONCLUSION: PAI-1 and adiponectin rendered the most robust associations with MetS components in a general population, indicating that unfavorable adipose tissue performance is a key contributor to these metabolic anomalies. Further prospective analyses should allow establishing whether these adipocytokines can anticipate the progress of MetS and cardiovascular risk.

Serum Alpha-1-Acid Glycoprotein-1 and Urinary Extracellular Vesicle miR-21-5p as Potential Biomarkers of Primary Aldosteronism.

Primary aldosteronism (PA) is the most common cause of secondary hypertension and reaches a prevalence of 6-10%. PA is an endocrine disorder, currently identified as a broad-spectrum phenotype, spanning from normotension to hypertension. In this regard, several studies have made advances in the identification of mediators and novel biomarkers of PA as specific proteins, miRNAs, and lately, extracellular vesicles (EVs) and their cargo. Aim: To evaluate lipocalins LCN2 and AGP1, and specific urinary EV miR-21-5p and Let-7i-5p as novel biomarkers for PA. Subjects and Methods: A cross-sectional study was performed in 41 adult subjects classified as normotensive controls (CTL), essential hypertensives (EH), and primary aldosteronism (PA) subjects, who were similar in gender, age, and BMI. Systolic (SBP) and diastolic (DBP) blood pressure, aldosterone, plasma renin activity (PRA), and aldosterone to renin ratio (ARR) were determined. Inflammatory parameters were defined as hs-C-reactive protein (hs-CRP), PAI-1, MMP9, IL6, LCN2, LCN2-MMP9, and AGP1. We isolated urinary EVs (uEVs) and measured two miRNA cargo miR-21-5p and Let-7i-5p by Taqman-qPCR. Statistical analyses as group comparisons were performed by Kruskall-Wallis, and discriminatory analyses by ROC curves were performed with SPSS v21 and Graphpad-Prism v9. Results: PA and EH subjects have significantly higher SBP and DBP (p <0.05) than the control group. PA subjects have similar hs-CRP, PAI-1, IL-6, MMP9, LCN2, and LCN2-MMP9 but have higher levels of AGP1 (p <0.05) than the CTL&EH group. The concentration and size of uEVs and miRNA Let-7i-5p did not show any difference between groups. In PA, we found significantly lower levels of miR-21-5p than controls (p <0.05). AGP1 was associated with aldosterone, PRA, and ARR. ROC curves detected AUC for AGP1 of 0.90 (IC 95 [0.79 - 1.00], p <0.001), and combination of AGP1 and EV-miR-21-5p showed an AUC of 0.94 (IC 95 [0.85 - 1.00], p<0.001) to discriminate the PA condition from EH and controls. Conclusion: Serum AGP1 protein was found to be increased, and miR-21-5p in uEVs was decreased in subjects classified as PA. Association of AGP1 with aldosterone, renin activity, and ARR, besides the high discriminatory capacity of AGP1 and uEV-miR-21-5p to identify the PA condition, place both as potential biomarkers of PA.

Testosterona inhibe la actividad de la aldosterona sintasa silvestre y quimérica in vitro / Testosterone inhibits human wild-type and chimeric aldosterone synthase activity in vitro

BACKGROUND: Familial hyperaldosteronism type I is caused by the generation of a chimeric aldosterone synthase enzyme (ASCE) which is regulated by ACTH instead of angiotensin II. We have reported that in vitro, the wild-type (ASWT) and chimeric aldosterone synthase (ASCE) enzymes are inhibited by progesterone and estradiol does not affect their activity. AIM: To explore the direct action of testosterone on ASWT and ASCE enzymes. Material and Methods: HEK-293 cells were transiently transfected with vectors containing the full ASWT or ASCE cDNAs. The effect of testosterone on AS enzyme activities was evaluated incubating HEK-cells transfected with enzyme vectors and adding deoxycorticosterone (DOC) alone or DOC plus increasing doses of testosterone. Aldosterone production was measured by HPLC-MS/MS. Docking of testosterone within the active sites of both enzymes was performed by modelling in silico. Results: In this system, testosterone inhibited ASWT (90% inhibition at five pM, 50% inhibitory concentration (IC50) =1.690 pM) with higher efficacy andpotency than ASCE (80% inhibition at five pM, IC50=3.176 pM). Molecular modelling studies showed different orientation of testosterone in ASWT and ASCE crystal structures. CONCLUSIONS: The inhibitory effect of testosterone on ASWT or ASCE enzymes is a novel non-genomic testosterone action, suggesting that further clinical studies are needed to assess the role of testosterone in the screening and diagnosis of primary aldosteronism.

Clinical Presentation and Perioperative Management of Pheochromocytomas and Paragangliomas: A 4-Decade Experience.

PURPOSE: Latin American reports on pheochromocytomas and paragangliomas (PPGLs) are scarce. Recent studies demonstrate changes in clinical presentation and management of these patients. Herein, we assessed the main characteristics of PPGL patients in our academic center over the past 4 decades. METHODS: Demographic, clinical, biochemical, and perioperative data from 105 PPGL patients were retrospectively and prospectively collected over the 1980-2019 period. Data were organized into 4 periods by decade. RESULTS: Age at diagnosis, gender, tumor size and percentage of bilaterality, percentage of paragangliomas, and metastases remained stable across the 4 decades. The proportion of genetic testing and incidentalomas increased in recent decades (all P < 0.001). Therefore, we compared PPGLs diagnosed as incidentalomas (36%) with those clinically suspected (64%). Incidentalomas had fewer adrenergic symptoms (38 vs. 62%; P < 0.001) and lower rates of hypertension (64% vs. 80%; P = 0.01) and hypertensive crisis (28% vs. 44%; P = 0.02); also, they had lower functionality (79% vs. 100%; P = 0.01) and lower catecholamines levels (8.4-fold vs. 12.5-fold above upper cutoffs; P = 0.04). Regarding management of all PPGLs over the decades, we observed significant increases in both perioperative doxazosin dose (P = 0.003) and laparoscopic approach rates (P < 0.001), along with a decrease in the length of hospital stays (P = 0.007). CONCLUSIONS: We observed a change in the clinical presentation of PPGL in recent decades, with a marked increase in incidental cases and milder symptoms. The implementation of a multidisciplinary program for adrenal disorders in our institution has translated into more timely diagnoses, more genetic testing, and improvements in perioperative management.

Novel metabolomic profile of subjects with non-classic apparent mineralocorticoid excess.

Nonclassic apparent mineralocorticoid excess (NC-AME) is proposed as a novel clinical condition with a mild phenotypic spectrum that ranges from normotension to severe hypertension. This condition is mainly characterized by a high serum cortisol to cortisone ratio (F/E) and concomitant low cortisone (E), however further metabolic changes in NC-AME have not been studied. A cross-sectional study was performed in a primary-care cohort of 396 Chilean subjects, which were classified in two groups: NC-AME (n = 28) and healthy controls (n = 27). A discovery study based in untargeted metabolomics assay in serum samples from both groups was performed by UPLC-Q-TOF/MS. Global metabolomic variations were assayed by principal component analysis and further compared by orthogonal partial least-squares discriminant analysis (OPLS-DA). NC-AME subjects exhibited higher values of blood pressure, fractional excretion of potassium, and lower plasma renin activity and urinary sodium to potassium ratio. Metabolomic analyses showed 36 differentially regulated metabolites between NC-AME and control subjects. A ROC curve analyses identified eight metabolites with high discriminatory capacity between NC-AME and control subjects. Moreover, gamma-L-glutamyl-L-methionine sulfoxide and 5-sulfoxymethylfurfural, exhibited significant association with cortisone, which are potential biomarkers of NC-AME, however further assays should elucidate its biological role in setup and progression of this phenotype.

Proteomic Profile of Urinary Extracellular Vesicles Identifies AGP1 as a Potential Biomarker of Primary Aldosteronism.

CONTEXT: Primary aldosteronism (PA) represents 6% to 10% of all essential hypertension patients and is diagnosed using the aldosterone-to-renin ratio (ARR) and confirmatory studies. The complexity of PA diagnosis encourages the identification of novel PA biomarkers. Urinary extracellular vesicles (uEVs) are a potential source of biomarkers, considering that their cargo reflects the content of the parent cell. OBJECTIVE: We aimed to evaluate the proteome of uEVs from PA patients and identify potential biomarker candidates for PA. METHODS: Second morning spot urine was collected from healthy controls (n = 8) and PA patients (n = 7). The uEVs were isolated by ultracentrifugation and characterized. Proteomic analysis on uEVs was performed using LC-MS Orbitrap. RESULTS: Isolated uEVs carried extracellular vesicle markers, showed a round shape and sizes between 50 and 150 nm. The concentration of uEVs showed a direct correlation with urinary creatinine (r = 0.6357; P = 0.0128). The uEV size mean (167 ±â€…6 vs 183 ±â€…4nm) and mode (137 ±â€…7 vs 171 ±â€…11nm) was significantly smaller in PA patients than in control subjects, but similar in concentration. Proteomic analysis of uEVs from PA patients identified an upregulation of alpha-1-acid glycoprotein 1 (AGP1) in PA uEVs, which was confirmed using immunoblot. A receiver operating characteristic curve analysis showed an area under the curve of 0.92 (0.82 to 1; P = 0.0055). CONCLUSION: Proteomic and further immunoblot analyses of uEVs highlights AGP1 as potential biomarker for PA.