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result(s) for
"Figueroa, Esteban G."
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Oxidative Stress in Polycystic Ovary Syndrome: Impact of Combined Oral Contraceptives
by
Echiburú, Bárbara
,
Maliqueo, Manuel
,
Figueroa, Esteban G.
in
Androgens
,
Antioxidants
,
Birth control
2024
Polycystic Ovary Syndrome (PCOS) is a complex hormonal disorder that is associated with heightened metabolic risks. While oxidative stress (OS) is known to play a role in PCOS, the precise nature of the relationship between PCOS and increased OS remains not entirely understood. Combined oral contraceptives (COCs) are the first-line treatment to regulate menstrual cycles and androgen levels, but their impact on oxidative stress requires further study. We conducted a transcriptomic analysis using RNAseq and assessed the levels of various oxidative stress (OS) markers in serum samples from women with PCOS and controls and whether they were using combined oral contraceptives (COCs), including enzymatic activities, FRAP, and 8-isoprostane (8-iso). A total of 359 genes were differentially expressed in women with PCOS compared to control women. Genes differentially expressed were enriched in functions related to inflammation and, interestingly, oxidative stress response. In controls, 8-iso levels were increased in women using COCs, whereas in women with PCOS, 8-iso levels were reduced in those using oral contraceptives (191.1 ± 97 vs. 26.4 ± 21 pg/mL, p: <0.0001). Correlation analyses showed a trend for a negative correlation between 8-iso and Ferriman score in women with PCOS consuming COCs (r = −0.86, p = 0.06) and a negative correlation between GSH and hyperandrogenism in women with PCOS (r = −0.89, p = 0.01). These results reveal the presence of lipid peroxidation in women with PCOS, which was modified by the use of COCs, providing new insights into the pathophysiology of PCOS in the Chilean population.
Journal Article
Melatonin Reduces Oxidative Stress in the Right Ventricle of Newborn Sheep Gestated under Chronic Hypoxia
by
Herrera, Emilio A.
,
Arias, Pamela V.
,
Ebensperger, Germán
in
antioxidant enzymes
,
Antioxidants
,
Blood pressure
2021
Pulmonary arterial hypertension of newborns (PAHN) constitutes a critical condition involving both severe cardiac remodeling and right ventricle dysfunction. One main cause of this condition is perinatal hypoxia and oxidative stress. Thus, it is a public health concern for populations living above 2500 m and in cases of intrauterine chronic hypoxia in lowlands. Still, pulmonary and cardiac impairments in PAHN lack effective treatments. Previously we have shown the beneficial effects of neonatal melatonin treatment on pulmonary circulation. However, the cardiac effects of this treatment are unknown. In this study, we assessed whether melatonin improves cardiac function and modulates right ventricle (RV) oxidative stress. Ten lambs were gestated, born, and raised at 3600 m. Lambs were divided in two groups. One received daily vehicle as control, and another received daily melatonin (1 mg·kg−1·d−1) for 21 days. Daily cardiovascular measurements were recorded and, at 29 days old, cardiac tissue was collected. Melatonin decreased pulmonary arterial pressure at the end of the experimental period. In addition, melatonin enhanced manganese superoxide dismutase and catalase (CAT) expression, while increasing CAT activity in RV. This was associated with a decrease in superoxide anion generation at the mitochondria and NADPH oxidases in RV. Finally, these effects were associated with a marked decrease of oxidative stress markers in RV. These findings support the cardioprotective effects of an oral administration of melatonin in newborns that suffer from developmental chronic hypoxia.
Journal Article
Oxidative Stress and NLRP3 Inflammasome as Markers of Cardiac Injury Following Cardiopulmonary Bypass: Potential Implications for Patients with Preoperative Heart Failure with Reduced Ejection Fraction
by
Pérez, Robert A.
,
Pagonas, Nikolaos
,
Herrera, Emilio A.
in
3-nitrotyrosine
,
Antioxidants
,
Biopsy
2025
Cardiopulmonary bypass (CPB) can lead to cardiac damage due to oxidative stress (OS) and inflammation in heart failure (HF). We tested the hypothesis that preoperative HF patients with reduced ejection fraction (HFrEF) subjected to CBP have higher levels of OS and NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3) in heart and plasma and in those that develop postoperative AF (pAF) as a clinical outcome. HF was categorized for preoperative left ventricular EF: preserved (HFpEF > 50%, n = 27) and reduced EF (HFrEF ≤ 40%, n = 25). Samples of atrial tissue, pericardial fluid, and plasma were collected at surgery to assess NLRP3 expression; 3-nitrotyrosine (3-NT), thiobarbituric acid reaction (TBARS), and nuclear factor erythroid 2-related factor 2 (Nrf2) in atrial tissue; NLRP3, IL-1β, and IL-18 expression in pericardial fluid; and antioxidant capacity, 8-isoprostanes, and malondialdehyde (MDA) in plasma. Reactive oxygen species, 3-NT, and NLRP3 in atrial tissue were determined by immunohistochemistry in a subset of pAF patients. Plasma and atrial tissue 3-NT and MDA were higher in HFrEF compared with HFpEF. Lipid peroxidation products were higher in both plasma and atrial tissue in pAF (n = 29), compared to sinus rhythm (SR) (n = 23). In HFrEF patients, the values of tissue ROS, 3-NT, and NLRP3 were higher than in HFpEF patients. In addition, the expression levels of NLRP3, IL-1β, and IL-18 were higher in atrial tissue and pericardial fluid in HFrEF. Patients with preoperative HFrEF showed higher OS in plasma and the expression of NLRP3, ROS, and 3-NT in atrial tissue biopsies and pericardial fluid. This finding suggests a potential pharmacologic therapy for pAF and clinical complications due to CPB.
Journal Article
Redox Imbalance Is Associated with Neuronal Apoptosis in the Cortex of Neonates Gestated Under Chronic Hypoxia
by
Jiménez, Tamara A.
,
Herrera, Emilio A.
,
Calle, Ximena
in
Antioxidants
,
Apoptosis
,
Biotechnology
2025
Gestational chronic hypoxia impacts prenatal development, leading to fetal growth restriction (FGR), defined as the fetus’s failure to reach its genetic growth potential. Postnatal hypoxia in the cerebral tissue can induce a redox imbalance and mitochondrial dysfunction, consequently increasing neuronal death. However, these data cannot necessarily be extrapolated to prenatal hypoxia. In this regard, this study aims to describe the effect of gestational hypoxia on redox balance and apoptosis cell death mechanisms in the prefrontal cortex of guinea pigs. Ten Guinea pig (Cavia porcellus) pregnant dams were utilized in this study; five gestated in normoxia (Nx; three newborn males, and two females) and five gestated under chronic hypobaric hypoxia (Hx; two newborn males, and three females). We monitored the pregnancies by ultrasound examinations from gestational days 20 to 65 (term ~ 70). At birth, pups were euthanized, and the fetal brain was collected for cellular redox measurement, mitochondrial enzyme expression, and apoptosis assay. Gestation under hypoxia induced an imbalance in the expression of anti- and pro-oxidant enzymes, resulting in increased oxidative stress. Additionally, a decrease in cytochrome I and III expression and neuronal density in the neonatal prefrontal cortex was observed. Finally, DNA fragmentation was increased by the TUNEL assay in the brain tissue of newborns gestated under chronic hypoxia. Our findings demonstrate the association of gestational hypoxia with oxidative stress and neuronal death in newborns, which may predispose to neuronal dysfunction in adulthood.
Journal Article
Effects of Exercise on Cardiovascular and Metabolic Responses in Adults and Childhood Cancer Survivors: The Role of NETosis and Low-Grade Inflammation as a Novel Therapeutic Target—A Narrative Review
2025
Cancer survivors (CS) constitute an expanding population with underrecognized cardiometabolic risk. Despite substantial improvements in five-year survival rates, both childhood and adult survivors remain at high risk for premature morbidity and mortality. These risks are particularly pronounced following exposure to anthracyclines and/or chest radiotherapy, typically in a dose-dependent manner. In Chile, the establishment of the National Pediatric Antineoplastic Drug Program (PINDA) in 1998 marked a milestone in improving equitable access to high-quality pediatric oncology care through evidence-based treatment protocols across the public health system; the adult counterpart (PANDA) has developed diagnostic, treatment, and monitoring protocols for hematological neoplasms. Few prospective cohort or mechanistic studies have clarified risk stratification or surveillance strategies in survivor populations. The regulated, short-term activation of inflammation and innate immunity can be an adaptive and protective response to tissue injury, whereas persistent low-grade inflammation may trigger neutrophil extracellular traps formation (NETosis) and other maladaptive pathways that accelerate endothelial injury, thrombosis, and adverse cardiovascular remodeling. NETosis represents a putative immunomodulatory target for therapeutic immunomodulation in heart failure and maladaptive left ventricular remodeling in preclinical models. Concurrently, skeletal muscle-derived and hormonal mediators known as exerkines—together with increased NET activity—may modulate the pathophysiology of chronic cardiometabolic disease and contribute to cancer progression, particularly in the context of obesity, diabetes, and insulin resistance. Structured exercise is a promising non-pharmacological intervention that modulates inflammatory and metabolic pathways and may thereby help prevent non-communicable diseases, including cancer. We synthesize basic and clinical evidence to (1) define how cancer therapies promote low-grade inflammation and NETosis; (2) describe how exerkines and structured exercise influence cardiometabolic biology; and (3) evaluate exercise as a mechanistic and clinically pragmatic strategy to reduce long-term CVD risk in pediatric and adult CS.
Journal Article
Development of a Panel of Genome-Wide Ancestry Informative Markers to Study Admixture Throughout the Americas
by
Escobedo, Jorge
,
Vargas, Enrique
,
Chapela, Rocio
in
African Continental Ancestry Group - genetics
,
American Native Continental Ancestry Group - genetics
,
Biology
2012
Most individuals throughout the Americas are admixed descendants of Native American, European, and African ancestors. Complex historical factors have resulted in varying proportions of ancestral contributions between individuals within and among ethnic groups. We developed a panel of 446 ancestry informative markers (AIMs) optimized to estimate ancestral proportions in individuals and populations throughout Latin America. We used genome-wide data from 953 individuals from diverse African, European, and Native American populations to select AIMs optimized for each of the three main continental populations that form the basis of modern Latin American populations. We selected markers on the basis of locus-specific branch length to be informative, well distributed throughout the genome, capable of being genotyped on widely available commercial platforms, and applicable throughout the Americas by minimizing within-continent heterogeneity. We then validated the panel in samples from four admixed populations by comparing ancestry estimates based on the AIMs panel to estimates based on genome-wide association study (GWAS) data. The panel provided balanced discriminatory power among the three ancestral populations and accurate estimates of individual ancestry proportions (R² > 0.9 for ancestral components with significant between-subject variance). Finally, we genotyped samples from 18 populations from Latin America using the AIMs panel and estimated variability in ancestry within and between these populations. This panel and its reference genotype information will be useful resources to explore population history of admixture in Latin America and to correct for the potential effects of population stratification in admixed samples in the region.
Journal Article
2734 Immunotherapy-Mediated Hemorrhagic Gastritis After Ipilimumab and Nivolumab Therapy
2019
INTRODUCTION:Combined checkpoint inhibitor immunotherapy with ipilimumab (anti-cytotoxic T-lymphocyte antigen 4 antibody) and nivolumab (anti-programmed cell death receptor 1 antibody) has greatly advanced the treatment of multiple malignancies but is associated with increased immune-related toxicities. Gastrointestinal toxicity is one of the most frequent adverse effects, and while lower GI tract toxicity, such as anti-CTLA-4-mediated colitis, is well known, severe toxicity of the upper GI tract is rare and not well described. We report a case of severe hemorrhagic gastritis in a patient after initiation of ipilimumab and nivolumab therapy for metastatic renal cell carcinoma.CASE DESCRIPTION/METHODS:A 70-year-old man with history of metastatic renal cell carcinoma and recent immune-related myocarditis initially presented with myasthenic weakness after receiving single doses of ipilimumab and nivolumab 5 weeks prior. His presentation was most consistent with seronegative, immune-mediated myasthenia gravis-like syndrome. He was treated with intravenous steroids and plasmapheresis. After 9 days of steroid therapy, he developed large volume melena requiring 4 units of blood despite twice-daily proton pump inhibitor therapy. Endoscopic evaluation revealed diffuse, severe inflammation with hemorrhage characterized by adherent blood and erythematous, friable gastric mucosa in the body, antrum, and prepyloric regions. Hemostatic spray was applied as a temporizing measure to control bleeding. Biopsy specimens demonstrated neutrophilic microabscesses with intraglandular apoptotic bodies, increased lymphocytes and scattered neutrophils in lamina propria, and reactive mucosal features. These findings were compatible with checkpoint inhibitor-induced acute gastritis. Immunohistochemical stains for H. pylori and cytomegalovirus were negative. Despite immunosuppressive therapy with high dose steroids, mycophenalate mofetil, and trial of infliximab, he continued to decline with ongoing anemia and progressive weakness. He was transitioned to comfort measures and died soon afterward.DISCUSSION:To our knowledge, this is the first reported case of severe hemorrhagic, non-infectious gastritis as a rare complication of immunotherapy with ipilimumab and nivolumab. Physicians should be aware that checkpoint inhibitor-induced toxicity of the upper GI tract can occur early after initiation of therapy and have a severe, refractory course. Management includes exclusion of infectious process and immunosuppressive therapy.
Journal Article
Clinical characteristics of full thickness macular holes that closed without surgery
by
Figueroa, Marta
,
Govindahari, Vishal
,
Foster, Robert
in
Anti-inflammatory agents
,
Cataracts
,
Clinical science
2022
PurposeTo ascertain the anatomic factors that help achieve non-surgical sealing in full thickness macular hole (FTMH).MethodsRetrospective collaborative study of FTMH that closed without surgical intervention.ResultsA total of 78 patients (mean age 57.9 years) included 18 patients with blunt ocular trauma, 18 patients that received topical or intravitreal therapies and 42 patients with idiopathic FTMH. Mean±SD of the initial corrected visual acuity (VA) in logMAR improved from 0.65±0.54 to 0.34±0.45 (p<0.001) at a mean follow-up of 33.8±37.1 months. FTMH reopened in seven eyes (9.0%) after a mean of 8.6 months. Vitreomacular traction was noted in 12 eyes (15.8%), perifoveal posterior vitreous detachment in 42 (53.8%), foveal epiretinal membrane in 10 (12.8%), cystoid macular oedema (CME) in 49 (62.8%) and subretinal fluid (SRF) in 20 (25.6%). By multivariate analysis, initial VA correlated to the height (p<0.001) and narrowest diameter of the hole (p<0.001) while final VA correlated to the basal diameter (p<0.001). Time for closure of FTMH (median 2.8 months) correlated to the narrowest diameter (p<0.001) and the presence of SRF (p=0.001). Mean time for closure (in months) was 1.6 for eyes with trauma, 4.3 for eyes without trauma but with therapy for CME, 4.4 for eyes without trauma and without therapy in less than 200 µm in size and 24.7 for more than 200 µm.ConclusionOur data suggest an observation period in new onset FTMH for non-surgical closure, in the setting of trauma, treatment of CME and size <200 µm.
Journal Article
Recovery course of foveal microstructure in the nonsurgical resolution of full-thickness macular hole
by
López-Guajardo, Lorenzo
,
Figueroa, Marta
,
Govindahari, Vishal
in
Acuity
,
Archives & records
,
Atrophy
2022
PurposeTo analyze the recovery course of foveal microstructures in eyes with nonsurgical healing of full-thickness macular hole (FTMH).MethodsBy serial OCT scans, the temporal healing sequences were analyzed in ocular trauma, vitreomacular traction (VMT), cystoid macular edema (CME), and the remaining group. We evaluated correlations between the final best-corrected spectacle visual acuity and reconstruction time of external limiting membrane (ELM), and inner segment/outer segment (IS/OS).ResultsThe healing (mean±standard deviation in months) most involved fusion at the level of the outer nuclear layer (ONL) (6.3±10.5) followed by restoration of ELM (9.1±13.8), and lastly, by IS/OS regeneration (13.1±19.5). In severe blunt ocular trauma, healing was fast and involved subretinal zipper glue-like reapposition with resulting outer retinal atrophy. Best spectacle-corrected visual acuity correlated with normalization of the clivus (p=0.012), faster ELM (p=0.006), and IS/OS reconstitution (p=0.024). Recurrence of FTMH occurred when the healing was halted (3 eyes) or was aberrant by lamellar hole epiretinal proliferation (LHEP) (3 eyes) or by the persistence of VMT (1 eye).ConclusionRecovery sequences proceeded from the ONL to the deeper layers with BCVA correlating absolutely and temporally with the restoration of outer retinal layer integrity.
Journal Article
Paneth and Paneth-like cells undergoing necroptosis fuel intestinal epithelial cell proliferation following IFN-γ stimulation
by
Jaimes-Ortega, Gustavo Alberto
,
Garcia-Sierra, Francisco
,
Medina-Contreras, Oscar
in
Physiology
2023
The quality of life in patients with inflammatory bowel diseases (IBD) is strongly impaired. Alterations of intestinal epithelial homeostasis contribute to the development and establishment of IBD. Intestinal Paneth and Paneth-like cells produce and secrete luminal proteins sustaining epithelial homeostasis. Here we show that IFN-γ stimulates Paneth and Paneth-like cells degranulation that triggers the proliferation of intestinal epithelial cells (IEC) in a Wnt/β-catenin independent manner. Degranulation in Paneth and Paneth-like cells was mTORC1 and necroptosis dependent. Remarkably, lack of IFN-γ, inhibition of mTORC1, or impeding necroptosis reduces IEC proliferation cytokine-mediated. Our findings identify a new role for IFN-γ in stimulating IEC proliferation through inducing degranulation of Paneth and Paneth-like cells which is mTORC1 and necroptosis- dependent. In a mouse model of colitis, mTORC1 activation and necroptosis regulate Paneth and Paneth-like cell secretion. Furthermore, the colitogenic environment triggers PC metaplasia in the distal region of the large intestine to simulate cell proliferation.
IFN-γ stimulates proliferation, β-catenin independent.
IFN-γ enhances mitochondrial activity and proliferation
IFN-γ regulates PC biogenesis.
mTORC1-dependent necroptosis mediates secretion in Paneth and Paneth-like cells.