Browsing by Author "Carvajal, Cristian A."
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- ItemAldosterone Promotes Autoimmune Damage by Enhancing Th17-Mediated Immunity(AMER ASSOC IMMUNOLOGISTS, 2010) Herrada, Andres A.; Contreras, Francisco J.; Marini, Natacha P.; Amador, Cristian A.; Gonzalez, Pablo A.; Cortes, Claudia M.; Riedel, Claudia A.; Carvajal, Cristian A.; Figueroa, Fernando; Michea, Luis F.; Fardella, Carlos E.; Kalergis, Alexis M.Excessive production of aldosterone leads to the development of hypertension and cardiovascular disease by generating an inflammatory state that can be promoted by T cell immunity. Because nature and intensity of T cell responses is controlled by dendritic cells (DCs), it is important to evaluate whether the function of these cells can be modulated by aldosterone. In this study we show that aldosterone augmented the activation of CD8(+) T cells in a DC-dependent fashion. Consistently, the mineralocorticoid receptor was expressed by DCs, which showed activation of MAPK pathway and secreted IL-6 and TGF-beta in response to aldosterone. In addition, DCs stimulated with aldosterone impose a Th17 phenotype to CD4(+) T cells, which have recently been associated with the promotion of inflammatory and autoimmune diseases. Accordingly, we observed that aldosterone enhances the progression of experimental autoimmune encephalomyelitis, an autoimmune disease promoted by Th17 cells. In addition, blockade of the mineralocorticoid receptor prevented all aldosterone effects on DCs and attenuated experimental autoimmune encephalomyelitis development in aldosterone-treated mice. Our data suggest that modulation of DC function by aldosterone enhances CD8(+) T cell activation and promotes Th17-polarized immune responses, which might contribute to the inflammatory damage leading to hypertension and cardiovascular disease. The Journal of Immunology, 2010, 184: 191-202.
- ItemAldosterone, Plasma Renin Activity, and Aldosterone/Renin Ratio in a Normotensive Healthy Pediatric Population(LIPPINCOTT WILLIAMS & WILKINS, 2010) Martinez Aguayo, Alejandro; Aglony, Marlene; Campino, Carmen; Garcia, Hernan; Bancalari, Rodrigo; Bolte, Lillian; Avalos, Carolina; Loureiro, Carolina; Carvajal, Cristian A.; Avila, Alejandra; Perez, Viviana; Inostroza, Andrea; Fardella, Carlos E.Primary aldosteronism is an important cause of secondary hypertension and is suspected in adults with an aldosterone/renin ratio >= 25. The normal aldosterone/renin ratio is unknown in children. The aim was to establish serum aldosterone, plasma renin activity, and aldosterone/renin ratio values in a healthy pediatric population. A cross-sectional study was performed in 211 healthy normotensive children (4 to 16 years old). Two subgroups of normotensive children were obtained: with hypertensive parents (NH) (n=113) and normotensive parents (n=98). Blood samples for measuring serum aldosterone, plasma renin activity, aldosterone/renin ratio, and DNA were collected. In subjects with aldosterone/renin ratio >= 25, the chimeric CYP11B1/CYP11B2 gene was investigated by long-extension PCR. Results are expressed as median [Q(1)-Q(3)]. NH and normotensive parents groups were similar in serum aldosterone (6.5 [3.6 to 9.0] ng/dL versus 6.5 [2.9 to 9.7] ng/dL; P=0.968) and plasma renin activity (2.3 [1.6 to 3.1] versus 2.4 [1.7 to 3.7] ng/mL per hour; P=0.129). The aldosterone/renin ratio was higher in the NH group, but this difference did not reach statistical significance (2.8 [1.9 to 4.1] versus 2.5 [1.4 to 4.0], P=0.104). In one subject of the NH group, the chimeric CYP11B1/CYP11B2 gene was detected. We demonstrated that normal aldosterone/renin ratio values in a healthy pediatric population without NH were lower than those reported for an adult normotensive population. (Hypertension. 2010;56:391-396.)
- ItemComparing Approaches to Normalize, Quantify, and Characterize Urinary Extracellular Vesicles(2021) Blijdorp, Charles J.; Tutakhel, Omar A. Z.; Hartjes, Thomas A.; van den Bosch, Thierry P. P.; van Heugten, Martijn H.; Rigalli, Juan Pablo; Willemsen, Rob; Musterd-Bhaggoe, Usha M.; Barros, Eric R.; Carles-Fontana, Roger; Carvajal, Cristian A.; Arntz, Onno J.; van de Loo, Fons A. J.; Jenster, Guido; Clahsen-van Groningen, Marian C.; Cuevas, Cathy A.; Severs, David; Fenton, Robert A.; van Royen, Martin E.; Hoenderop, Joost G. J.; Bindels, Rene J. M.; Hoorn, Ewout J.Background: Urinary extracellular vesicles (uEVs) are a promising source for biomarker discovery, but optimal approaches for normalization, quantification, and characterization in spot urines are unclear.
- ItemCortisol resistance in the degu (Octodon degus)(2022) Yao, Yi-Zhou; Brennan, Francine E.; Carvajal, Cristian A.; Vecchiola, Andrea; Tapia-Castillo, Alejandra; Fardella, Carlos E.; Fuller, Peter J.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.
- ItemIncreased urinary glucocorticoid metabolites are associated with metabolic syndrome, hypoadiponectinemia, insulin resistance and beta cell dysfunction(ELSEVIER SCIENCE INC, 2011) Baudrand, Rene; Campino, Carmen; Carvajal, Cristian A.; Olivieri, Oliviero; Guidi, Giancesare; Faccini, Giovanni; Sateler, Javiera; Cornejo, Javiera; San Martin, Betty; Dominguez, Jose M.; Cerda, Jaime; Mosso, Lorena M.; Owen, Gareth I.; Kalergis, Alexis M.; Fardella, Carlos E.Metabolic syndrome (MetS) may have increased cortisol (F) production caused by 11 beta-hydroxysteroid dehydrogenase 1 (11 beta-HSD1) in liver and adipose tissue and/or by HPA axis dysregulation. F is then mainly metabolized by liver reductases into inactive tetrahydrometabolites (THMs). We measured THM levels in patients with or without MetS and evaluate the correlation between THMs and anthropometric and biochemical parameters. We recruited 221 subjects, of whom 130 had MetS by ATP III. We evaluated F, cortisone (E), adipokines, glucose, insulin and lipid profiles as well as urinary (24 h) F. E and THM levels. beta Cell function was estimated by the HOMA Calculator. We observed that patients with MetS showed higher levels of THMs, HOMA-IR and leptin and lower levels of adiponectin and HOMA-beta but no differences in F and E in plasma or urine. THM was associated with weight (r = +0.44, p < 0,001), waist circumference (r = +0.38, p < 0.01). glycemia (r = +0.37, p < 0.01), and triglycerides (r = +0.18, p = 0.06) and negatively correlated with adiponectin (r = -0.36, p < 0.001), HOMA-beta (r = -0.21, p < 0.001) and HDL (r = -0.29, p < 0.01). In a logistic regression model, THM levels were associated with hypertension, hyperglycemia and dyslipidemia. We conclude that MetS is associated with increased urinary THMs but not with F and E levels in plasma or urine. Increased levels of THM, reflecting the daily cortisol production subsequently metabolized, are correlated with hypoadiponectinemia, hypertension, dyslipidemia, insulin resistance and beta cell dysfunction. A subtle increased in glucocorticoid production may further account for the phenotypic and biochemical similarities observed in central obesity and Cushing's syndrome. (C) 2011 Elsevier Inc. All rights reserved.
- ItemMicroribonucleic acid-21 increases aldosterone secretion and proliferation in H295R human adrenocortical cells(ENDOCRINE SOC, 2008) Romero, Damian G.; Plonczynski, Maria W.; Carvajal, Cristian A.; Gomez Sanchez, Elise P.; Gomez Sanchez, Celso E.MicroRNAs (miRNAs) are endogenous small noncoding RNAs that decrease the expression levels of specific genes by translational repression, sequestration, and degradation of their mRNAs. Angiotensin II is an important modulator of adrenal zona glomerulosa cell physiology, including steroidogenesis and proliferation among many other physiological processes. Because each miRNA may regulate the expression levels of multiple genes, thereby resembling the transcription regulatory networks triggered by transcription factors, we hypothesize that specific miRNAs may be involved in angiotensin II-mediated adrenocortical cell physiology. The human adrenocortical cell line H295R is the only adrenal cell line available with a steroid secretion pattern and regulation similar to freshly isolated adrenocortical cells. We screened for miRNAs regulated by angiotensin II in H295R cells and found that miRNA-21 expression levels were specifically modulated by angiotensin II. Angiotensin II time dependently increased miRNA-21 expression reaching a 4.4-fold induction after 24 h. Angiotensin II-mediated miRNA-21 expression resulted in biologically active miRNA-21, determined using a fusion mRNA reporter system carrying miRNA-21 target sequences in its 3' untranslated region. Up-regulation of miRNA-21 intracellular levels increased aldosterone secretion but not cortisol. Elevation of miRNA-21 levels also increased cell proliferation in H295R cells. In summary, miRNA-21 is an endogenously expressed miRNA in human adrenal cells. miRNA-21 expression is up-regulated by angiotensin II, and its overexpression caused an increase in aldosterone secretion and cell proliferation. Alterations in miRNA-21 expression levels or function may be involved in dysregulation of angiotensin II signaling and abnormal aldosterone secretion by adrenal glands in humans.
- ItemOverexpression of 11 beta-hydroxysteroid dehydrogenase type 1 in visceral adipose tissue and portal hypercortisolism in non-alcoholic fatty liver disease(WILEY, 2012) Candia, Roberto; Riquelme, Arnoldo; Baudrand, Rene; Carvajal, Cristian A.; Morales, Mauricio; Solis, Nancy; Pizarro, Margarita; Escalona, Alex; Carrasco, Gonzalo; Boza, Camilo; Perez, Gustavo; Padilla, Oslando; Cerda, Jaime; Fardella, Carlos E.; Arrese, MarcoBackground: The enzyme 11 beta-hydroxysteroid-dehydrogenase type 1 (11 beta HSD1) catalyses the reactivation of intracellular cortisol. We explored the potential role of 11 beta-HSD1 overexpression in visceral adipose tissue (VAT) in non-alcoholic fatty liver disease (NAFLD) assessing sequential changes of enzyme expression, in hepatic and adipose tissue, and the occurrence of portal hypercortisolism in obese mice. 11 beta-HSD1 expression was also assessed in tissues from obese patients undergoing bariatric surgery. Methods: Peripheral and portal corticosterone levels and liver histology were assessed in ob/ob mice at two time points (8-12 weeks of age). 11 beta-HSD1 tissue expression was assessed in by RT-pcr in ob/ob mice and in 49 morbidly obese patients. Results: Portal corticosterone serum levels were higher in obese mice with a 26% decrease between 8 and 12 weeks of age (controls: 78.3 +/- 19.7 ng/ml, 8-week-old ob/ob: 167.5 +/- 14.5 ng/ml and 12-week-old ob/ob: 124.3 +/- 28 ng/ml, P < 0.05). No significant differences were found in peripheral corticosterone serum levels. Expression of 11b-HSD1 was lower in the liver [-45% at 8 weeks and -35% at 12-weeks (P = 0.0001)] and highly overexpressed in VAT in obese mice, compared to controls (128-fold higher in 8-week-old ob/ob and 41-fold higher in 12-week-old ob/ob, P < 0.01). No significant differences were seen in the expression of 11 beta-HSD1 in subcutaneous adipose tissue. In multivariate analysis, human 11 beta-HSD1 expression in VAT (OR: 1.385 +/- 1.010-1.910) was associated with NAFLD. Conclusion: Murine NAFLD is associated with portal hypercortisolism and 11 beta-HSD1 overexpression in VAT. In humans, 11 beta-HSD1 VAT expression was associated with the presence of NAFLD. Thus, local corticosteroid production in VAT may contribute to NAFLD pathogenesis.
- ItemPlasminogen Activator Inhibitor-1 and Adiponectin Are Associated With Metabolic Syndrome Components(2022) Vecchiola, Andrea; Garcia, Killen; Gonzalez-Gomez, Luis M.; Tapia-Castillo, Alejandra; Artigas, Rocio; Baudrand, Rene; Kalergis, Alexis M.; Carvajal, Cristian A.; Fardella, Carlos E.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 (R-2 = 0.125; P = 0.04); diastolic BP (R-2 = 0.218; P = 0.0001) and glucose (R-2 = 0.074; P = 0.0001) could be predicted by PAI-1; waist circumference could be predicted by PAI-1 and hs-CRP (R-2 = 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.
- ItemProteomic Profile of Urinary Extracellular Vesicles Identifies AGP1 as a Potential Biomarker of Primary Aldosteronism(2021) Barros, Eric R.; Rigalli, Juan Pablo; Tapia-Castillo, Alejandra; Vecchiola, Andrea; Young, Morag J.; Hoenderop, Joost G. J.; Bindels, Rene J. M.; Fardella, Carlos E.; Carvajal, Cristian A.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.