Metabolic syndrome (MetS) has become one of the main concerns for public health because of its link to cardiovascular disease. Murine models have been used to study the effect of MetS on the ...cardiovascular system, but they have limitations for studying cardiac electrophysiology. In contrast, the rabbit cardiac electrophysiology is similar to human, but a detailed characterization of the different components of MetS in this animal is still needed. Our objective was to develop and characterize a diet-induced experimental model of MetS that allows the study of cardiovascular remodeling and arrhythmogenesis. Male NZW rabbits were assigned to control (n = 15) or MetS group (n = 16), fed during 28 weeks with high-fat, high-sucrose diet. We measured weight, morphological characteristics, blood pressure, glycaemia, standard plasma biochemistry and the metabolomic profile at weeks 14 and 28. Liver histological changes were evaluated using hematoxylin-eosin staining. A mixed model ANOVA or unpaired t-test were used for statistical analysis (P<0.05). Weight, abdominal contour, body mass index, systolic, diastolic and mean arterial pressure increased in the MetS group at weeks 14 and 28. Glucose, triglycerides, LDL, GOT-AST, GOT/GPT, bilirubin and bile acid increased, whereas HDL decreased in the MetS group at weeks 14 and 28. We found a 40% increase in hepatocyte area and lipid vacuoles infiltration in the liver from MetS rabbits. Metabolomic analysis revealed differences in metabolites related to fatty acids, energetic metabolism and microbiota, compounds linked with cardiovascular disease. Administration of high-fat and high-sucrose diet during 28 weeks induced obesity, glucose intolerance, hypertension, non-alcoholic hepatic steatosis and metabolic alterations, thus reproducing the main clinical manifestations of the metabolic syndrome in humans. This experimental model should provide a valuable tool for studies into the mechanisms of cardiovascular problems related to MetS, with special relevance in the study of cardiovascular remodeling, arrhythmias and SCD.
Candida auris is an emergent multidrug-resistant fungal pathogen considered a severe global threat due to its capacity to cause nosocomial outbreaks and deep-seated infections with high ...transmissibility and mortality. However, evidence on its pathogenicity and the complex host-pathogen interactions is still limited. This study used the
invertebrate model in Galleria mellonella to assess its virulence, exploring the mortality kinetics, melanization response, and morphological changes after fungal infection compared to Candida albicans and Candida parapsilosis, with known high and low pathogenicity, respectively. All C. auris isolates presented less virulence than C. albicans strains but higher than that induced by C. parapsilosis isolates. Increased pathogenicity was observed in nonaggregative phenotypes of C. auris, while the melanization response of the larvae to fungal infection was homogeneous and independent of the causing species. C. auris was able to filament in the
animal model G. mellonella, with aggregative and nonaggregative phenotypes presenting various pseudohyphal formation degrees as pathogenicity determinants in a strain-dependent manner. Histological invasiveness of C. auris mimicked that observed for C. albicans, with effective dissemination since the early stages of infection both in yeast and filamented forms, except for a remarkable respiratory tropism not previously observed in other yeasts. These characteristics widely differ between strains and advocate the hypothesis that the morphogenetic variability of C. auris is an indicator of its flexibility and adaptability, contributing to its emergence and rising worldwide prevalence.
Candida auris is an emergent fungus that has become a global threat due to its multidrug resistance, mortality, and transmissibility. These unique features make it different from other
species, but we still do not fully know the degree of virulence and, especially, the host-pathogen interactions. In this
insect model, we found that it presents an intermediate degree of virulence compared to known high- and low-virulence
species but with significant variability between aggregative and nonaggregative strains. Although it was previously considered unable to filament, we documented
filamentation as an important pathogenic determinant. We also found that it is able to disseminate early through the host, invading both the circulatory system and many different tissues with a remarkable respiratory tropism not previously described for other yeasts. Our study provides new insights into the pathogenicity of an emergent fungal pathogen and its interaction with the host and supports the hypothesis that its morphogenetic variability contributes to its rising global prevalence.
Candida auris has globally emerged as a multidrug-resistant fungus linked to healthcare-associated outbreaks. There is still limited evidence on its virulence, pathogenicity determinants, and complex ...host-pathogen interactions. This study analyzes the in vivo fungal behaviour, immune response, and host-pathogen interactions upon C. auris infection compared to C. albicans and C. parapsilosis in G. mellonella. This was performed by immunolabelling fungal structures and larval plasmatocytes and using a quantitative approach incorporating bioinformatic morphometric techniques into the study of microbial pathogenesis. C. auris presents a remarkably higher immunogenic activity than expected at its moderate degree of tissue invasion. It induces a greater inflammatory response than C. albicans and C. parapsilosis at the expense of plasmatocyte nodule formation, especially in non-aggregative strains. It specifically invades the larval respiratory system, in a pattern not previously observed in other Candida species, and presents inter-phenotypic tissue tropism differences. C. auris filaments in vivo less frequently than C. albicans or C. parapsilosis mostly through pseudohyphal growth. Filamentation might not be a major pathogenic determinant in C. auris, as less virulent aggregative phenotypes form pseudohyphae to a greater extent. C. auris has important both interspecific and intraspecific virulence and phenotype heterogeneity, with aggregative phenotypes of C. auris sharing characteristics with low pathogenic species such as C. parapsilosis. Our work suggests that C. auris owns an important morphogenetic plasticity that distinguishes it from other yeasts of the genus. Routine phenotypic identification of aggregative or non-aggregative phenotypes should be performed in the clinical setting as it may impact patient management.
The development of biomaterials for myocardial tissue engineering requires a careful assessment of their performance with regards to functionality and biocompatibility, including the immune response. ...Poly(3-hydroxybutyrate) (PHB), poly(e-caprolactone) (PCL), silk, poly-lactic acid (PLA), and polyamide (PA) scaffolds were generated by electrospinning, and cell compatibility in vitro, and immune response and cardiac function in vitro and in vivo were compared with a noncrosslinked collagen membrane (Col) control material. Results showed that cell adhesion and growth of mesenchymal stem cells, cardiomyocytes, and cardiac fibroblasts in vitro was dependent on the polymer substrate, with PHB and PCL polymers permitting the greatest adhesion/growth of cells. Additionally, polymer substrates triggered unique expression profiles of anti- and pro-inflammatory cytokines in human peripheral blood mononuclear cells. Implantation of PCL, silk, PLA, and PA patches on the epicardial surface of healthy rats induced a classical foreign body reaction pattern, with encapsulation of polymer fibers and induction of the nonspecific immune response, whereas Col and PHB patches were progressively degraded. When implanted on infarcted rat heart, Col, PCL, and PHB reduced negative remodeling, but only PHB induced significant angiogenesis. Importantly, Col and PHB modified the inflammatory response to an M2 macrophage phenotype in cardiac tissue, indicating a more beneficial reparative process and remodeling. Collectively, these results identify PHB as a superior substrate for cardiac repair.
Mesenchymal stem cells (MSC) are effective in treating myocardial infarction (MI) and previous reports demonstrated that hypoxia improves MSC self-renewal and therapeutics. Considering that ...hypoxia-inducible factor-1 alpha (HIF-1α) is a master regulator of the adaptative response to hypoxia, we hypothesized that HIF-1α overexpression in MSC could mimic some of the mechanisms triggered by hypoxia and increase their therapeutic potential without hypoxia stimulation. Transduction of MSC with HIF-1α lentivirus vectors (MSC-HIF) resulted in increased cell adhesion and migration, and activation of target genes coding for paracrine factors. When MSC-HIF were intramyocardially injected in infarcted nude rats, significant improvement was found (after treatment of infarcted rats with MSC-HIF) in terms of cardiac function, angiogenesis, cardiomyocyte proliferation, and reduction of fibrotic tissue with no induction of cardiac hypertrophy. This finding provides evidences for a crucial role of HIF-1α on MSC biology and suggests the stabilization of HIF-1α as a novel strategy for cellular therapies.
Extracellular vesicles (EVs) derived from dental pulp mesenchymal stem cells (DP-MSCs) are a promising therapeutic option for the treatment of myocardial ischemia. The aim of this study is to ...determine whether MSC-EVs could promote a pro-resolving environment in the heart by modulating macrophage populations.
EVs derived from three independent biopsies of DP-MSCs (MSC-EVs) were isolated by tangential flow-filtration and size exclusion chromatography and were characterized by omics analyses. Biological processes associated with these molecules were analyzed using String and GeneCodis platforms. The immunomodulatory capacity of MSC-EVs to polarize macrophages towards a pro-resolving or M2-like phenotype was assessed by evaluating surface markers, cytokine production, and efferocytosis. The therapeutic potential of MSC-EVs was evaluated in an acute myocardial infarction (AMI) model in nude rats. Infarct size and the distribution of macrophage populations in the infarct area were evaluated 7 and 21 days after intramyocardial injection of MSC-EVs.
Lipidomic, proteomic, and miRNA-seq analysis of MSC-EVs revealed their association with biological processes involved in tissue regeneration and regulation of the immune system, among others. MSC-EVs promoted the differentiation of pro-inflammatory macrophages towards a pro-resolving phenotype, as evidenced by increased expression of M2 markers and decreased secretion of pro-inflammatory cytokines. Administration of MSC-EVs in rats with AMI limited the extent of the infarcted area at 7 and 21 days post-infarction. MSC-EV treatment also reduced the number of pro-inflammatory macrophages within the infarct area, promoting the resolution of inflammation.
EVs derived from DP-MSCs exhibited similar characteristics at the omics level irrespective of the biopsy from which they were derived. All MSC-EVs exerted effective pro-resolving responses in a rat model of AMI, indicating their potential as therapeutic agents for the treatment of inflammation associated with AMI.
Objectives The purpose of this study was to compare the ability of human CD34+ hematopoietic stem cells and bone marrow mesenchymal stem cells (MSC) to treat myocardial infarction (MI) in a model of ...permanent left descendent coronary artery (LDA) ligation in nude rats. Background Transplantation of human CD34+ cells and MSC has been proved to be effective in treating MI, but no comparative studies have been performed to elucidate which treatment prevents left ventricular (LV) remodelling more efficiently. Methods Human bone marrow MSC or freshly isolated CD34+ cells from umbilical cord blood were injected intramyocardially in infarcted nude rats. Cardiac function was analyzed by echocardiography. Ventricular remodelling was evaluated by tissue histology and electron microscopy, and neo-formed vessels were quantified by immunohistochemistry. Chronic local inflammatory infiltrates were evaluated in LV wall by hematoxylin-eosin staining. Apoptosis of infarcted tissue was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Results Both cell types induced an improvement in LV cardiac function and increased tissue cell proliferation in myocardial tissue and neoangiogenesis. However, MSC were more effective for the reduction of infarct size and prevention of ventricular remodelling. Scar tissue was 17.48 ± 1.29% in the CD34 group and 10.36 ± 1.07% in the MSC group (p < 0.001 in MSC vs. CD34). Moreover, unlike MSC, CD34+ -treated animals showed local inflammatory infiltrates in LV wall that persisted 4 weeks after transplantation. Conclusions Mesenchymal stem cells might be more effective than CD34+ cells for the healing of the infarct. This study contributes to elucidate the mechanisms by which these cell types operate in the course of MI treatment.
BACKGROUND Implantation of a retrogradely-shed endometrium during menstruation requires an adequate blood supply. The endometrium has angiogenic potential, and endometriotic lesions grow in areas ...with a rich vascularization, suggesting that angiogenesis is a prerequisite for endometriosis development. Targeting vascular endothelial growth factor (VEGF) leads to an inhibition of endometriosis. Dopamine and its agonists, such as cabergoline (Cb2), promote VEGF receptor-2 (VEGFR-2) endocytosis in endothelial cells, preventing VEGF–VEGFR-2 binding and reducing neoangiogenesis. The aim of this study was to evaluate the anti-angiogenic properties of Cb2 on growth of established endometriosis lesions and investigate the molecular mechanisms by which Cb2 exerts the anti-angiogenic effect. METHODS Human endometrium fragments were implanted in female nude mice peritoneum, and mice were treated with vehicle, 0.05 or 0.1 mg/kg/day oral Cb2 for 14 days. After treatment, the implants were processed to assess proliferative activity, neoangiogenesis, VEGFR-2 phosphorylation and angiogenic gene expression. RESULTS A significant decrease in the percentage of active endometriotic lesions (P < 0.05) and cellular proliferation index (P < 0.001) was found with Cb2 treatment. Neoangiogenesis was reduced by Cb2 treatment, as observed at gross morphological level and by significant changes in gene expression. The degree of VEGFR-2 phosphorylation was significantly lower in Cb2-treated animals than controls. CONCLUSIONS Cb2 treatment in experimental endometriosis has an anti-angiogenic effect acting through VEGFR-2 activation. These findings support the testing of dopamine agonists as a novel therapeutic approach to peritoneal endometriosis in humans.
Clinical and experimental studies have shown that, in patients with reperfused ST-segment elevation myocardial infarction (STEMI), abnormalities in the endothelial monolayer are initiated during ...ischemia but rapidly intensify upon restoration of blood perfusion to the ischemic area. We aimed to evaluate the effect of serum isolated after revascularization from STEMI patients on the degree of endothelial permeability in vitro, by promoting endothelial cell apoptosis and necrosis in vitro. We also investigated the association between the percentage of serum-induced endothelial cell apoptosis or necrosis in vitro and the extent of cardiovascular magnetic resonance (CMR)-derived parameters of reperfusion injury (edema, hemorrhage, and microvascular obstruction).
Human coronary artery endothelial cells were incubated with serum isolated 24hours after revascularization from 43 STEMI patients who underwent CMR and 14 control participants. We assessed the effect of STEMI serum on activation of apoptosis and necrosis, as well as on the permeability and structure of the endothelial monolayer.
Serum from STEMI patients increased apoptosis (P <.01) and necrosis (P <.05) in human coronary artery endothelial cells and caused increased permeability of the endothelial monolayer in vitro (P <.01), due to enlarged intercellular spaces (P <.05 vs control in all cases). Higher serum-induced necrosis was associated with greater endothelial permeability in vitro (P <.05) and with more extensive CMR-derived indices of reperfusion injury and infarct size.
Postreperfusion serum activates necrosis and apoptosis in endothelial cells and increases the degree of endothelial permeability in vitro. The more potent the necrosis-triggering effect of serum, the more deleterious the consequences in terms of the resulting cardiac structure.
La reperfusión coronaria produce un daño en la microcirculación y, en concreto, las células endoteliales. Este estudio evalúa el efecto del suero aislado tras la revascularización de pacientes con un infarto agudo de miocardio con elevación del segmento ST (IAMCEST) en la viabilidad celular, el grado de permeabilidad endotelial in vitro y la asociación de estos parámetros con una mayor extensión de los índices de resonancia magnética cardiaca (RMC) relacionados con el daño por reperfusión (edema, hemorragia y obstrucción microvascular).
Se incubaron células endoteliales de arteria coronaria humana con suero aislado 24 h tras la revascularización de 43 pacientes con IAMCEST evaluados mediante RMC y 14 sujetos de control. Se testó el efecto del suero de pacientes con IAMCEST en la pérdida de viabilidad celular por activación de la apoptosis y la necrosis, así como en la permeabilidad y la estructura de la monocapa endotelial.
El suero de pacientes con IAMCEST aumentó la apoptosis (p <0,01) y la necrosis (p <0,05) de células endoteliales de arteria coronaria humana y causó un incremento de la permeabilidad de la monocapa endotelial in vitro (p <0,01) debido a mayores espacios intercelulares (p <0,05 frente a los controles). Una mayor necrosis inducida por suero se asoció con más permeabilidad endotelial in vitro (p <0,05) y con una mayor extensión de los principales índices de daño tras reperfusión y mayor tamaño de infarto.
El suero tras la reperfusión de pacientes con IAMCEST induce la apoptosis y la necrosis in vitro de las células endoteliales y la permeabilidad endotelial. Cuanto más potente sea el efecto inductor de necrosis, más deletéreas son las consecuencias en cuanto al daño estructural resultante.
To analyze the presence of mature and immature vessels as a prognostic factor in patients with renal cell carcinoma and propose a classification of renal cancer tumor blood vessels according to ...morphometric parameters. Tissue samples were obtained from 121 renal cell carcinoma patients who underwent radical nephrectomy. Staining with CD31 and CD34 was used to differentiate between immature (CD31+) and mature (CD34+) blood vessels. We quantified the microvascular density, microvascular area and different morphometric parameters: maximum diameter, minimum diameter, major axis, minor axis, perimeter, radius ratio and roundness. We found that the microvascular density was higher in CD31+ than CD34+ vessels, but CD34+ vessels were larger than CD31+ vessels, as well as being strongly correlated with the ISUP tumor grade. We also identified four vascular patterns: pseudoacinar, fascicular, reticular and diffuse. Pseudoacinar and fascicular patterns were more frequent in clear cell renal cell carcinoma (37.62 and 35.64% respectively), followed by reticular pattern (21.78%), while in chromophobe tumors the reticular pattern predominated (90%). The isolated pattern was present in all papillary tumors (100%). In healthy renal tissue, the pseudoacinar and isolated patterns were differentially found in the renal cortex and medulla respectively. We defined four distinct vascular patterns significantly related with the ISUP tumor grade in renal cell carcinomas. Further studies in larger series are needed in order to validate these results. Analysis of both mature and immature vessels (CD34+ and CD31+) provides additional information when evaluating microvascular density.
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