Interferon-ß decreases LPS-induced neutrophil recruitment to cardiac fibroblasts.

Introduction: Cardiac fibroblasts (CF) are crucial cells in damaged heart tissues, expressing TLR4, IFN-receptor and responding to lipopolysaccharide (LPS) and interferon-ß (IFN-ß) respectively. While CF interact with immune cells; however, their relationship with neutrophils remains understudied. Additionally, theimpact of LPS and IFN-ß on CF-neutrophil interaction is poorly understood. Methods: Isolated CF from adult rats were treated with LPS, with or without IFN-ß. This study examined IL-8 secretion, ICAM-1 and VCAM-1 expression, and neutrophil recruitment, as well as their effects on MMPs activity. Results: LPS triggered increased IL-8 expression and secretion, along with elevated ICAM-1 and VCAM-1 expression, all of which were blocked by TAK-242. Pre-treatment with IFN-ß countered these LPS effects. LPS treated CF showed higher neutrophil recruitment (migration and adhesion) compared to unstimulated CF, an effect prevented by IFN-ß. Ruxolitinib blocked these IFN-ß anti-inflammatory effects, implicating JAK signaling. Analysis of culture medium zymograms from CF alone, and CF-neutrophils interaction, revealed that MMP2 was mainly originated from CF, while MMP9 could come from neutrophils. LPS and IFN-ß boosted MMP2 secretion by CF. MMP9 activity in CF was low, and LPS or IFN-ß had no significant impact. Pre-treating CF with LPS, IFN-ß, or both before co-culture with neutrophils increased MMP2. Neutrophil co-culture increased MMP9 activity, with IFN-ß pre-treatment reducing MMP9 compared to unstimulated CF. Conclusion: In CF, LPS induces the secretion of IL-8 favoring neutrophils recruitment and these effects were blocked by IFN-. The results highlight that CF-neutrophil interaction appears to influence the extracellular matrix through MMPs activity modulation.

SGK1 is necessary to FoxO3a negative regulation, oxidative stress and cardiac fibroblast activation induced by TGF-ß1.

Cardiac fibroblasts (CFs) activation is a common response to most pathological conditions affecting the heart, characterized by increased cellular secretory capacity and increased expression of fibrotic markers, such as collagen I and smooth muscle actin type alpha (α-SMA). Fibrotic activation of CFs induces the increase in tissue protein content, with the consequent tissue stiffness, diastolic dysfunction, and heart failure. Therefore, the search for new mechanisms of CFs activation is important to find novel treatments for cardiac diseases characterized by fibrosis. In this regard, TGF-ß1, a cytokine with proinflammatory and fibrotic properties, is crucial in the CFs activation and the development of fibrotic diseases, whereas its molecular targets are not completely known. Serum and glucocorticoid-regulated kinase (SGK1) is a protein involved in various pathophysiological phenomena, especially cardiac and renal diseases that curse with fibrosis. Additionally, SGK1 phosphorylates and regulates the activity and expression of several targets, highlighting FoxO3a for its role in the regulation of oxidative stress and CFs activation induced by TGF-ß1. However, the regulation of SGK1 by TGF-ß1 and its role in CFs activation have not been studied. In this work, we evaluate the role of SGK1 in CFs isolated from neonatal Sprague-Dawley rats. The participation of SGK1 in the fibrotic activation of CFs induced by TGF-ß1 was analyzed, using an inhibitor or siRNA of SGK1. In addition, the role of SGK1 on the regulation of FoxO3a and oxidative stress induced by TGF-ß1 was analyzed. Our results indicate that TGF-ß1 increased both the activity and expression of SGK1 in CFs, requiring the activation of MAPKs, ERK1/2, p38 and JNK, while inhibition and silencing of SGK1 prevented TGF-ß1-induced fibrotic activation of CFs. In addition, SGK1 inhibition prevented FoxO3a inactivation and expression reduction, catalase and SOD2 expression decrease, and the increase of oxidative stress induced by TGF-ß1. Taken together, our results position SGK1 as an important regulator of CFs activation driven by TGF-ß1, at least in part, through the regulation of FoxO3a and oxidative stress.

Exposure of the Gestating Mother to Sympathetic Stress Modifies the Cardiovascular Function of the Progeny in Male Rats.

BACKGROUND: Sympathetic stress stimulates norepinephrine (NE) release from sympathetic nerves. During pregnancy, it modifies the fetal environment, increases NE to the fetus through the placental NE transporter, and affects adult physiological functions. Gestating rats were exposed to stress, and then the heart function and sensitivity to in vivo adrenergic stimulation were studied in male progeny. METHODS: Pregnant Sprague-Dawley rats were exposed to cold stress (4 °C/3 h/day); rats' male progeny were euthanized at 20 and 60 days old, and their hearts were used to determine the ß-adrenergic receptor (ßAR) (radioligand binding) and NE concentration. The in vivo arterial pressure response to isoproterenol (ISO, 1 mg/kg weight/day/10 days) was monitored in real time (microchip in the descending aorta). RESULTS: Stressed male progeny presented no differences in ventricular weight, the cardiac NE was lower, and high corticosterone plasma levels were recorded at 20 and 60 days old. The relative abundance of ß1 adrenergic receptors decreased by 36% and 45%, respectively (p < 0.01), determined by Western blot analysis without changes in ß2 adrenergic receptors. A decrease in the ratio between ß1/ß2 receptors was found. Displacement of 3H-dihydroalprenolol (DHA) from a membrane fraction with propranolol (ß antagonist), atenolol (ß1 antagonist), or zinterol (ß2 agonist) shows decreased affinity but no changes in the ß-adrenergic receptor number. In vivo exposure to ISO to induce a ß-adrenergic overload provoked death in 50% of stressed males by day 3 of ISO treatment. CONCLUSION: These data suggest permanent changes to the heart's adrenergic response after rat progeny were stressed in the uterus.

Lipoxin A4 prevents high glucose-induced inflammatory response in cardiac fibroblast through FOXO1 inhibition.

Cardiac cells respond to various pathophysiological stimuli, synthesizing inflammatory molecules that allow tissue repair and proper functioning of the heart; however, perpetuation of the inflammatory response can lead to cardiac fibrosis and heart dysfunction. High concentration of glucose (HG) induces an inflammatory and fibrotic response in the heart. Cardiac fibroblasts (CFs) are resident cells of the heart that respond to deleterious stimuli, increasing the synthesis and secretion of both fibrotic and proinflammatory molecules. The molecular mechanisms that regulate inflammation in CFs are unknown, thus, it is important to find new targets that allow improving treatments for HG-induced cardiac dysfunction. NFκB is the master regulator of inflammation, while FoxO1 is a new participant in the inflammatory response, including inflammation induced by HG; however, its role in the inflammatory response of CFs is unknown. The inflammation resolution is essential for an effective tissue repair and recovery of the organ function. Lipoxin A4 (LXA4) is an anti-inflammatory agent with cytoprotective effects, while its cardioprotective effects have not been fully studied. Thus, in this study, we analyze the role of p65/NFκB, and FoxO1 in CFs inflammation induced by HG, evaluating the anti-inflammatory properties of LXA4. Our results demonstrated that HG induces the inflammatory response in CFs, using an in vitro and ex vivo model, while FoxO1 inhibition and silencing prevented HG effects. Additionally, LXA4 inhibited the activation of FoxO1 and p65/NFκB, and inflammation of CFs induced by HG. Therefore, our results suggest that FoxO1 and LXA4 could be novel drug targets for the treatment of HG-induced inflammatory and fibrotic disorders in the heart.

Senescent cardiac fibroblasts: A key role in cardiac fibrosis.

Cardiac fibroblasts are a cell population that controls the homeostasis of the extracellular matrix and orchestrates a damage response to maintain cardiac architecture and performance. Due to these functions, fibroblasts play a central role in cardiac fibrosis development, and there are large differences in matrix protein secretion profiles between fibroblasts from aged versus young animals. Senescence is a multifactorial and complex process that has been associated with inflammatory and fibrotic responses. After damage, transient cellular senescence is usually beneficial, as these cells promote tissue repair. However, the persistent presence of senescent cells within a tissue is linked with fibrosis development and organ dysfunction, leading to aging-related diseases such as cardiovascular pathologies. In the heart, early cardiac fibroblast senescence after myocardial infarction seems to be protective to avoid excessive fibrosis; however, in non-infarcted models of cardiac fibrosis, cardiac fibroblast senescence has been shown to be deleterious. Today, two new classes of drugs, termed senolytics and senostatics, which eliminate senescent cells or modify senescence-associated secretory phenotype, respectively, arise as novel therapeutical strategies to treat aging-related pathologies. However, further studies will be needed to evaluate the extent of the utility of senotherapeutic drugs in cardiac diseases, in which pathological context and temporality of the intervention must be considered.

Physical fitness mediates the inverse association between fatness indicators and academic achievement, despite the school vulnerability of adolescents-The Cogni-Action Project.

Objective: This study aims to determine the mediating role of physical fitness in the relationship between fatness indicators and academic achievement, exploring the influence of school vulnerability. Methods: A total of 1,296 Chilean adolescents (aged 10 to 14 years; 50% girls) participated in this study. The global fitness score (GFS) was obtained by adding the three main components of the ALPHA fitness test: cardiorespiratory fitness (CRF), muscular fitness (MF), and speed/agility fitness (SAF). CRF was evaluated through the 20 m shuttle run test; MF by upper and lower limb strength tests; and SAF by the 4 × 10 shuttle run test. BMIz and WHtR were evaluated as general (unspecific) and central (specific) fatness indicators. Academic achievement was established through grades in math, language, and science and their average scores. Multiple mediation analyses were performed according to two models, adjusted for sex, maturity, and schools (model 1), and in model 2, the school vulnerability index (SVI) was added. The SVI is an important proxy of socioeconomic status at the school level, and it was categorized as high-, mid-, or low-SVI. Mediation percentages were calculated, and confidence intervals (bootstrapping) were used to establish significant findings. Results: CRF, SAF, and GFS mediate the relationship between fatness indicators and academic achievement, both partially and totally (ranging from 12.7 to 59.2%). However, MF did not show any mediation effect. After controlling for SVI, CRF, and GFS, mediation changed from partial to total in the associations between math and science with WHtR. Although SAF contributed to GFS mediation, CRF seems to have the most significant mediation role for all academic achievements, regardless of SVI and the fat indicator studied. Conclusion: A higher level of general physical fitness, especially CRF, significantly mediates the detrimental influence of fatness on the academic achievement of schoolchildren. This study suggests that physical fitness plays a relevant role in academic and public health, considering the high prevalence and detrimental influence of obesity and school vulnerability in children and adolescents.

Which one? A comparative study of traditional and sports uniforms on academic achievement, cognitive performance, playtime, bullying, and discrimination in adolescents: The Cogni-Action Project.

Objective: The aim of this study was to compare academic achievement, cognitive performance, playtime, bullying, and discrimination in adolescents according to traditional uniforms (TUs) and sports uniforms (SUs) worn at school, while simultaneously exploring the influence of the school vulnerability index. Methods: A total of 988 Chilean adolescents (52.6% boys) aged 10-14 years participated in this cross-sectional study. Academic achievement was evaluated by the average grade in maths, language, and science grades, while cognitive performance was assessed through eight cognitive tasks. TUs affecting physical activity, playtime, bullying, and discrimination were queried. Mixed model analyses were performed. Results: No differences were observed in academic achievement (TU: 5.4 ± 0.1 vs. SU: 5.5 ± 0.2, p = 0.785) or in cognitive performance (TU: 99.6 ± 0.8 vs. SU: 98.9 ± 1.8, p= 0.754) according to the school uniformtype. Moreover, 64.1 % of participants declared that wearing TU affects their physical activity (traditional uniforms: + 8 min and sports uniforms: + 20 min), and those who believed so spent more time playing than those who answered negatively (14.5 min, p = 0.012). Finally, adolescents wearing SU displayed a lower feeling of bullying and discrimination; this finding depended mainly on the school's vulnerability. Conclusion: It is concluded that wearing TU does not show an educational advantage at an academic and cognitive level that justifies its obligation. In addition, it could be suggested that schools consider adolescents' opinions in adopting a more comfortable uniform, such as the SU. This feasible and low-cost measure would help to increase adolescents' physical activity during the school day, and, contrary to belief, it would not be related to increased feelings of bullying and discrimination.

Resolvin E1 attenuates doxorubicin-induced cardiac fibroblast senescence: A key role for IL-1ß.

Cardiac fibroblasts (CFs) undergo senescence in reaction to different stressors, leading to a poor prognosis of cardiac disease. Doxorubicin (Doxo) is an antineoplastic drug with strong cardiotoxic effects, which induces IL-1ß secretion and thus, triggers a potent pro-inflammatory response. Doxo induces CFs senescence; however, the mechanisms are not fully understood. Different pharmacological strategies have been used to eliminate senescent cells by inducing their apoptosis or modifying their secretome. However, Resolvin E1 (RvE1), a lipid derivative resolutive mediator with potent anti-inflammatory effects has not been used before to prevent CFs senescence. CFs were isolated from adult male C57BL/6J mice and subsequently stimulated with Doxo, in the presence or absence of RvE1. Senescence-associated ß-galactosidase activity (SA-ß-gal), γ-H2A.X, p53, p21, and senescence-associated secretory phenotype (SASP) were evaluated. The involvement of the NLRP3 inflammasome/interleukin-1 receptor (IL-1R) signaling pathway on CFs senescence was studied using an NLRP3 inhibitor (MCC950) and an endogenous IL-1R antagonist (IR1A). Doxo is able to trigger CFs senescence, as evidenced by an increase of γ-H2A.X, p53, p21, and SA-ß-gal, and changes in the SASP profile. These Doxo effects were prevented by RvE1. Doxo triggers IL-1ß secretion, which was dependent on NLRP3 activation. Doxo-induced CFs senescence was partially blocked by MCC950 and IR1A. In addition, IL-1ß also triggered CFs senescence, as evidenced by the increase of γ-H2A.X, p53, p21, SA-ß-gal activity, and SASP. All these effects were also prevented by RvE1 treatment. CONCLUSION: These data show the anti-senescent role of RvE1 in Doxo-induced CFs senescence, which could be mediated by reducing IL-1ß secretion.

Angiotensin II Triggers NLRP3 Inflammasome Activation by a Ca2+ Signaling-Dependent Pathway in Rat Cardiac Fibroblast Ang-II by a Ca2+-Dependent Mechanism Triggers NLRP3 Inflammasome in CF.

Angiotensin II (Ang-II) is a widely studied hypertensive, profibrotic, and pro-inflammatory peptide. In the heart, cardiac fibroblasts (CF) express type 1 angiotensin II receptors (AT1R), Toll-like receptor-4 (TLR4), and the NLRP3 inflammasome complex, which play important roles in pro-inflammatory processes. When activated, the NLRP3 inflammasome triggers proteolytic cleavage of pro-IL-1, resulting in its activation. However, in CF the mechanism by which Ang-II assembles and activates the NLRP3 inflammasome remains not fully known. To elucidate this important point, we stimulated TLR4 receptors in CF and evaluated the signaling pathways by which Ang-II triggers the assembly and activity. In cultured rat CF, pro-IL-1ß levels, NLRP3, ASC, and caspase-1 expression levels were determined by Western blot. NLRP3 inflammasome complex assembly was analyzed by immunocytochemistry, whereas by ELISA, we analyzed NLRP3 inflammasome activity and [Formula: see text] release. In CF, Ang-II triggered NLRP3 inflammasome assembly and caspase-1 activity; and in LPS-pretreated CF, Ang-II also triggered [Formula: see text] secretion. These effects were blocked by losartan (AT1R antagonist), U73221 (PLC inhibitor), 2-APB (IP3R antagonist), and BAPTA-AM (Ca2+ chelator) indicating that the AT1R/PLC/IP3R/Ca2+ pathway is involved. Finally, bafilomycin A1 prevented Ang-II-induced [Formula: see text] secretion, indicating that a non-classical protein secretion mechanism is involved. These findings suggest that in CF, Ang-II by a Ca2+-dependent mechanism triggers NLRP3 inflammasome assembly and activation leading to [Formula: see text] secretion through a non-conventional protein secretion mechanism.

Resolvin E1 attenuates doxorubicin-induced endothelial senescence by modulating NLRP3 inflammasome activation.

Endothelial cell senescence contributes to chronic inflammation and endothelial dysfunction, while favoring cardiovascular disorders and frailty. Senescent cells acquire a pro-inflammatory secretory phenotype that further propagates inflammation and senescence to neighboring cells. Cell senescence can be provoked by plethora of stressors, including inflammatory molecules and chemotherapeutic drugs. Doxorubicin (Doxo) is a powerful anthracycline anticancer drug whose clinical application is constrained by a dose-limiting cardiovascular toxicity. We here investigated whether cell senescence can contribute to the vascular damage elicited by Doxo. In human umbilical vein endothelial cells (HUVEC) cultures, Doxo (10-100 nM) increased the number of SA-ß-gal positive cells and the levels of γH2AX, p21 and p53, used as markers of senescence. Moreover, we identified Doxo-induced senescence to be mediated by the nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasome, a key player of the immune innate system capable of releasing interleukin (IL)-1ß. In fact, IL-1ß itself mimicked the stimulatory action of Doxo on both NLRP3 activation and cellular senescence, while the pharmacological blockade of IL-1 receptors markedly attenuated the pro-senescence effects of Doxo. In search of additional pharmacological strategies to attenuate Doxo-induced endothelial senescence, we identified resolvin E1 (RvE1), an endogenous pro-resolving mediator, as capable of reducing cell senescence induced by both Doxo and IL-1ß by interfering with the increased expression of pP65, NLRP3, and pro-IL-1ß proteins and with the formation of active NLRP3 inflammasome complexes. Overall, RvE1 and the blockade of the NLRP3 inflammasome-IL-1ß axis may offer a novel therapeutic approach against Doxo-induced cardiovascular toxicity and subsequent sequelae.

Implicit Subgrid-Scale Modeling of a Mach 2.5 Spatially Developing Turbulent Boundary Layer.

We employ numerically implicit subgrid-scale modeling provided by the well-known streamlined upwind/Petrov-Galerkin stabilization for the finite element discretization of advection-diffusion problems in a Large Eddy Simulation (LES) approach. Whereas its original purpose was to provide sufficient algorithmic dissipation for a stable and convergent numerical method, more recently, it has been utilized as a subgrid-scale (SGS) model to account for the effect of small scales, unresolvable by the discretization. The freestream Mach number is 2.5, and direct comparison with a DNS database from our research group, as well as with experiments from the literature of adiabatic supersonic spatially turbulent boundary layers, is performed. Turbulent inflow conditions are generated via our dynamic rescaling-recycling approach, recently extended to high-speed flows. Focus is given to the assessment of the resolved Reynolds stresses. In addition, flow visualization is performed to obtain a much better insight into the physics of the flow. A weak compressibility effect is observed on thermal turbulent structures based on two-point correlations (IC vs. supersonic). The Reynolds analogy (u' vs. t') approximately holds for the supersonic regime, but to a lesser extent than previously observed in incompressible (IC) turbulent boundary layers, where temperature was assumed as a passive scalar. A much longer power law behavior of the mean streamwise velocity is computed in the outer region when compared to the log law at Mach 2.5. Implicit LES has shown very good performance in Mach 2.5 adiabatic flat plates in terms of the mean flow (i.e., Cf and UVD+). iLES significantly overpredicts the peak values of u', and consequently Reynolds shear stress peaks, in the buffer layer. However, excellent agreement between the turbulence intensities and Reynolds shear stresses is accomplished in the outer region by the present iLES with respect to the external DNS database at similar Reynolds numbers.

Pharmacological Blockade of NLRP3 Inflammasome/IL-1ß-Positive Loop Mitigates Endothelial Cell Senescence and Dysfunction.

The clinical relevance of IL-1ß in chronic inflammation underlying atherosclerosis has been reinforced by recent evidence associating pharmacological inhibition of the cytokine with lower cardiovascular risk. Previously, we have demonstrated a direct involvement of IL-1ß in endothelial senescence. Therefore, this can be a key mechanism contributing to the sterile inflammatory milieu associated with aging, termed inflammaging. In the present study, we have evaluated whether a positive feedback of IL-1ß in the NLRP3 inflammasome via NF-κB could promote human endothelial senescence in vitro and murine endothelial dysfunction in vivo. Our results indicate that the NLRP3 inflammasome is pivotal in mediating the detrimental effects of IL-1ß, showing that auto-activation is a crucial feature boosting endothelial cell senescence in vitro, which is paralleled by vascular dysfunction in vivo. Hence, the inhibitor of NLRP3 inflammasome assembly, MCC 950, was able to disrupt the aforementioned positive loop, thus alleviating inflammation, cell senescence and vascular dysfunction. Besides, we explored alternative NLRP3 inflammasome inhibitory agents such as the RAS heptapeptide Ang-(1-7) and the anti-aging protein klotho, both of which demonstrated protective effects in vitro and in vivo. Altogether, our results highlight a fundamental role for the hereby described NLRP3 inflammasome/IL-1ß positive feedback loop in stress-induced inflammaging and the associated vascular dysfunction, additionally providing evidence of a potential therapeutic use of MCC 950, Ang-(1-7) and recombinant klotho to block this loop and its deleterious effects.

Composición corporal, parámetros bioeléctricos y fuerza de prensión manual en escaladores chilenos federados y recreativos / Body composition, bioelectrical parameters, and handgrip strength in federated and recreational Chilean climbers

RESUMEN: El objetivo del siguiente estudio fue determinar y comparar los valores de composición corporal, parámetros bioeléctricos y fuerza de prensión manual de escaladores chilenos federados y recreativos. Participaron voluntariamente 13 escaladores chilenos, de los cuales 4 eran federados (25,75 ± 2,87 años) y 9 recreativos (22,33 ± 1,41 años). La composición corporal se evaluó por medio de un impedanciómetro bioeléctrico octopolar multifrecuencia, mientras que la fuerza de prensión manual se determinó con un dinamómetro manual. Si bien no hubo diferencias en las variables de composición corporal entre ambos grupos, el ángulo de fase del tronco fue superior en los federados en comparación a los recreativos (p = 0,011 [95 % IC = 1,10; 5,20]). Respecto a la fuerza de prensión manual, la fuerza relativa fue superior para los federados (p = 0,025 [95 % IC = 0,10; 0,22]), mientras que la diferencia de la fuerza entre la mano dominante y no dominante fue mayor para los recreativos (p = 0,012 [95 % IC = 1,60; 10,05]). Este es uno de los primeros estudios que explora las diferencias entre escaladores chilenos federados y recreativos. Los resultados sugieren una diferenciación a nivel de ángulo de fase y fuerza de prensión manual, lo cual debería corroborarse con futuros estudios.

SUMMARY: This study aimed to determine and compare the body composition, bioelectric parameters, and handgrip strength in federated and recreational Chilean climbers. Thirteen Chilean climbers voluntarily participated, being 4 federated (25.75 ± 2.87 years) and 9 recreational (22.33 ± 1.41 years). Body composition was measured using a multifrequency octopolar bioelectrical impedance meter, while handgrip strength was determined with a dynamometer. Although there were no statistical differences in the body composition variables between groups, the trunk phase angle was statistically higher in the federated compared to the recreational climbers (p = 0,011 [95 % CI = 1,10; 5,20]). Regarding handgrip strength, the relative strength was higher for federated (p = 0,025 [95 % CI = 0,10; 0,22]), while the difference in strength between dominant and non-dominant hand was higher for recreational climbers (p = 0,012 [95 % CI = 1,60; 10,05]). This study is one of the first that explore the differences between federated and recreational Chilean climbers. These results suggest a differentiation at the level of phase angle and handgrip strength, which should be corroborated in future studies.

Aspirin-triggered resolvin D1 reduces parasitic cardiac load by decreasing inflammation in a murine model of early chronic Chagas disease.

BACKGROUND: Chagas disease, caused by the protozoan Trypanosoma cruzi, is endemic in Latin America and is widely distributed worldwide because of migration. In 30% of cases, after years of infection and in the absence of treatment, the disease progresses from an acute asymptomatic phase to a chronic inflammatory cardiomyopathy, leading to heart failure and death. An inadequate balance in the inflammatory response is involved in the progression of chronic Chagas cardiomyopathy. Current therapeutic strategies cannot prevent or reverse the heart damage caused by the parasite. Aspirin-triggered resolvin D1 (AT-RvD1) is a pro-resolving mediator of inflammation that acts through N-formyl peptide receptor 2 (FPR2). AT-RvD1 participates in the modification of cytokine production, inhibition of leukocyte recruitment and efferocytosis, macrophage switching to a nonphlogistic phenotype, and the promotion of healing, thus restoring organ function. In the present study, AT-RvD1 is proposed as a potential therapeutic agent to regulate the pro-inflammatory state during the early chronic phase of Chagas disease. METHODOLOGY/PRINCIPAL FINDINGS: C57BL/6 wild-type and FPR2 knock-out mice chronically infected with T. cruzi were treated for 20 days with 5 µg/kg/day AT-RvD1, 30 mg/kg/day benznidazole, or the combination of 5 µg/kg/day AT-RvD1 and 5 mg/kg/day benznidazole. At the end of treatment, changes in immune response, cardiac tissue damage, and parasite load were evaluated. The administration of AT-RvD1 in the early chronic phase of T. cruzi infection regulated the inflammatory response both at the systemic level and in the cardiac tissue, and it reduced cellular infiltrates, cardiomyocyte hypertrophy, fibrosis, and the parasite load in the heart tissue. CONCLUSIONS/SIGNIFICANCE: AT-RvD1 was shown to be an attractive therapeutic due to its regulatory effect on the inflammatory response at the cardiac level and its ability to reduce the parasite load during early chronic T. cruzi infection, thereby preventing the chronic cardiac damage induced by the parasite.

Determinación de la morfología del canal incisivo mandibular mediante tomografía computarizada de haz cónico (CBCT) en población de Valdivia, Chile / Determination of mandibular incisor canal morphology by cone beam computed tomography (CBCT) in a population of Valdivia, Chile

RESUMEN: El canal incisivo mandibular (MIC) es un canal neural que contiene una de las ramas inferiores del nervio alveolar inferior, llamado nervio incisivo mandibular, que puede resultar dañado durante intervenciones quirúrgicas y causar complicaciones postoperatorias. Estudio descriptivo de corte transversal. Se identificó el MIC en la imagen transversal del canino en 83 hemiarcadas. Se registró edad, sexo, hemiarcada, longitudes desde reborde alveolar vestibular de canino a MIC, cortical lingual y vestibular de canino a MIC, base mandibular de canino a MIC y ubicación del MIC (tercio lingual, medio, vestibular). Medidas se registraron en milímetros. Se aplicó test T-student para muestras independientes para variables de longitud y Chi-cuadrado para ubicación espacial del MIC, en relación con grupo etario y sexo. Se evaluó el MIC en todas las muestras (100 %). El MIC fue encontrado mayormente en el tercio medio mandibular (p <0,05). La media desde el MIC a la cortical lingual es de 5,25 mm ? 1,42 mm (derecho) y 5,24 mm ? 1,18 mm (izquierdo). La media desde el MIC a la cortical vestibular fue de 4,42 mm ? 1,29 mm (derecho) y 4,53 mm ? 1,24mm (izquierdo). La media entre centro del canal y reborde alveolar vestibular fue 18,89 mm ? 2,68mm (derecho) y 18,20 mm ? 3,06 mm (izquierdo), media desde centro del MIC al margen basal fue de 9,77 mm ? 1,93 (derecho) y 10,12 mm ? 1,92 mm (izquierdo). Se encontró mayor distribución del MIC en el tercio medio mandibular. Se identificó el MIC en el 100 % de las muestras a través de CBCT por lo que su uso como examen complementario debe ser considerado al planificar cirugías en el sector anterior mandibular.

SUMMARY: The objective of the study was to determine the morphology of the mandibular incisive canal (MIC) and its location using cone beam computed tomography (CBCT) in the population of Valdivia, Chile. Descriptive cross-sectional study. MIC was identified in the canine cross image in 83 quadrants. Age, gender, quadrants, length from buccal alveolar ridge of canine to MIC, lingual and buccal cortical of canine to MIC, mandibular base of canine to MIC, and location of MIC (lingual, middle and buccal third) were recorded. Measurements were recorded in millimeters. Independent sample Student-T test was performed to determine length variables and Chi-square test was performed to determine spatial location of MIC, in relation to age group and gender. MIC was evaluated in all samples (100 %). MIC was found mainly in the mandibular third quadrant (p < 0.05). The mean from the MIC to the lingual cortex is 5.25 mm ? 1.42 mm (right) and 5.24 mm ? 1.18 mm (left). The mean from the MIC to the buccal cortex was 4.42 ? 1.29 mm (right) and 4.53 mm ? 1.24 mm (left). The mean between the center of the canal and the buccal alveolar ridge was 18.89 mm ? 2.68mm (right) and 18.20 mm ? 3.06 mm (left), the mean from the center of the MIC to the basal edge was 9.77 mm ? 1.93 (right) and 10.12 mm ? 1.92 mm (left). A greater distribution of MIC was found in the mandibular third quadrant. MIC was identified in 100 % of the samples through CBCT, therefore, its use as a complementary examination should be considered when planning surgeries in the anterior mandibular area.

Frecuencia y caracterización de foramen mental accesorio en una población chilena mediante tomografía computarizada de haz cónico / Frequency and characterization of accessory mental foramen in a Chilean population using cone beam computed tomography

RESUMEN: En la práctica clínica odontológica, reconocer estructuras anatómicas es determinante en la planificación de distintos tratamientos que involucren algún riesgo. Uno de los exámenes complementarios recomendados para la planificación de diferentes tratamientos en odontología es la Tomografía Computarizada de Haz Cónico (CBCT). Con este examen, se pueden pesquisar variantes anatómicas como el Foramen Mental Accesorio (FMA), el cual es importante identificar para prevenir complicaciones. El objetivo de este trabajo fue determinar la frecuencia y caracterización de FMA en una población chilena adulta, de la ciudad de Valdivia, Chile. Este estudio es de tipo observacional descriptivo. Se revisaron 247 exploraciones de diferentes centros radiológicos de la ciudad de Valdivia, cumpliendo 143 con los criterios de selección. Este estudio fue aprobado por el Comité ético científico del Servicio de Salud de Valdivia. Se encontró presencia de FMA en el 17,48 % que corresponde a 25 pacientes de un total de 143, correspondiendo un 80 % al sexo femenino. El rango etario en que se encontró con mayor frecuencia correspondió a 18-39 años. La distancia promedio entre FMA y FM (Foramen Mental) fue de 5,76 mm, correspondiendo a 2 mm la distancia mínima y 11,5 mm la distancia máxima. La distancia promedio entre FMA y ápice dentario más cercano fue de 5,36 mm. La distancia mínima y máxima fueron de 0,8 mm y 10,2 mm respectivamente. El ápice radicular mayormente asociado al FMA correspondió al segundo premolar con una frecuencia de 60 % (n=15). Este estudio confirma la importancia de la correcta evaluación de la región mental ante procedimientos en la zona, la cual es vital para prevenir lesiones en relación a esta variante anatómica.

SUMMARY: The recognition of key anatomical structures is decisive to avoid complications in the dental clinical practice. Cone Beam Computed Tomography (CBCT) is a complementary exam recommended for the planning of different procedures in dentistry. With this exam, anatomical variants can be identified, such as the Accessory Mental Foramen (AMF). The objective of this work was to determine the frequency and characteristics of AMF in an adult Chilean population from the city of Valdivia, Chile. This is an observational study that included 247 CBCT exams from different radiological centers in Valdivia. According to the selection criteria, 143 CBCT exams were included. This study was approved by the Scientific Ethics Committee of the Valdivia Health Services. AMF was identified in 25 patients representing 17.48 %. From this result, 80 % were found in females. AMF was most frequently identified in patients from 18 to 39 years old. The average distance between AMF and Mental Foramen (MF) was 5.76 mm, which corresponds to 2 mm the minimum distance and 11.5 mm the maximum distance. The average distance between AMF and the nearest dental apex was 5.36 mm, and the minimum and maximum distance were 0.8 mm and 10.2 mm, respectively. The root apex of the second premolar was most frequently associated with the AMF, representing 60 % (n=15). This study confirms the importance of the correct evaluation of the mental region before initiating procedures in the area, which is vital to prevent injuries associated with this anatomical variant.

Resolvin-D1 attenuation of angiotensin II-induced cardiac inflammation in mice is associated with prevention of cardiac remodeling and hypertension.

AIMS: Despite the broad pharmacological arsenal to treat hypertension, chronic patients may develop irreversible cardiac remodeling and fibrosis. Angiotensin II, the main peptide responsible for the Renin-Angiotensin-Aldosterone-System, has been closely linked to cardiac remodeling, hypertrophy, fibrosis, and hypertension, and some of these effects are induced by inflammatory mediators. Resolvin-D1 (RvD1) elicits potent anti-inflammatory and pro-resolving effects in various pathological models. In this study, we aimed to examine whether RvD1 ameliorates cardiac remodeling and hypertension triggered by angiotensin II. METHODS AND RESULTS: Alzet® osmotic mini-pumps filled with angiotensin II (1.5 mg/kg/day) were implanted in male C57BL/6 J mice for 7 or 14 days. RvD1 (3 µg/kg/day, i.p) was administered one day after the surgery and during the complete infusion period. Blood pressure and myocardial functional parameters were assessed by echocardiography. At the end of the experimental procedure, blood and heart tissue were harvested, and plasma and histological parameters were studied. After 7 and 14 days, RvD1 reduced the increase of neutrophil and macrophage infiltration triggered by angiotensin II, and also reduced ICAM-1 and VCAM-1 expression levels. RvD1 also reduced cytokine plasma levels (IL-1ß, TNF-α, IL-6, KC, MCP-1), cardiac hypertrophy, interstitial and perivascular fibrosis, and hypertension. CONCLUSIONS: This study unveils novel cardioprotective effects of RvD1 in angiotensin II-induced hypertension and cardiac remodeling by attenuating inflammation and provides insights into a potential clinical application.

Resolvin D1 reduces expression and secretion of cytokines and monocyte adhesion triggered by Angiotensin II, in rat cardiac fibroblasts.

Cardiac fibroblasts (CF) play an important role in the healing process and in pathological remodeling of cardiac tissue. As sentinel cells in the heart, they respond to inflammatory stimuli, expressing cytokines and cell adhesion proteins, which ultimately lead to increased recruitment of monocytes and enhancement of the inflammatory response. Angiotensin II (Ang II) triggers an inflammatory response, leading to cardiac tissue remodeling. On the other hand, RvD1 has been shown to contribute to the resolution of inflammation; however, its role in Ang II-treated CF has not been addressed until now. The present research aimed to study the effect of RvD1 on cytokine levels, cell adhesion proteins expression in a model of Ang II-triggered inflammatory response. CF from adult Sprague Dawley rats were used to study mRNA and protein levels of MCP-1, IL-6, TNF-a, IL-10, ICAM-1 and VCAM-1; and adhesion of spleen mononuclear cells to CF after Ang II stimulation. Our results show that Ang II increased IL-6, MCP-1 and TNF-a mRNA levels, but only increased IL-6 and MCP-1 protein levels. These effects were blocked by Losartan, but not by PD123369. Moreover, RvD1 was able to prevent all Ang II effects in CF. Additionally, RvD1 reduced the intracellular Ca2+ increase triggered by Ang II, indicating that RvD1 acts in an early manner to block Ang II signaling. Conclusion: our findings confirm the pro-resolutive effects of inflammation by RvD1, which at the cardiovascular level, could contribute to repair damaged cardiac tissue.

Toll-Like Receptor 4 Activation Prevents Rat Cardiac Fibroblast Death Induced by Simulated Ischemia/Reperfusion.

Death of cardiac fibroblasts (CFs) by ischemia/reperfusion (I/R) has major implications for cardiac wound healing. In in vivo models of myocardial infarction, toll-like receptor 4 (TLR4) activation has been reported as a cardioprotector; however, it remains unknown whether TLR4 activation can prevent CF death triggered by simulated I/R (sI/R). In this study, we analyzed TLR4 activation in neonate CFs exposed to an in vitro model of sI/R and explored the participation of the pro-survival kinases Akt and ERK1/2. Simulated ischemia was performed in a free oxygen chamber in an ischemic medium, whereas reperfusion was carried out in normal culture conditions. Cell viability was analyzed by trypan blue exclusion and the MTT assay. Necrotic and apoptotic cell populations were evaluated by flow cytometry. Protein levels of phosphorylated forms of Akt and ERK1/2 were analyzed by Western blot. We showed that sI/R triggers CF death by necrosis and apoptosis. In CFs exposed only to simulated ischemia or only to sI/R, blockade of the TLR4 with TAK-242 further reduced cell viability and the activation of Akt and ERK1/2. Preconditioning with lipopolysaccharide (LPS) or treatment with LPS in ischemia or reperfusion was not protective. However, LPS incubation during both ischemia and reperfusion periods prevented CF viability loss induced by sI/R. Furthermore, LPS treatment reduced the sub-G1 population, but not necrosis of CFs exposed to sI/R. On the other hand, the protective effects exhibited by LPS were abolished when TLR4 was blocked and Akt and ERK1/2 were inhibited. In conclusion, our results suggest that TLR4 activation protects CFs from apoptosis induced by sI/R through the activation of Akt and ERK1/2 signaling pathways.