Browsing by Author "Carvajal, Cristian A."

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Cortisol 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.
  • No Thumbnail Available
    Item
    Plasminogen 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.
  • No Thumbnail Available
    Item
    Proteomic 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.