A Network Comprised of miR-15b and miR-29a Is Involved in Vascular Endothelial Growth Factor Pathway Regulation in Thymus Adipose Tissue from Elderly Ischemic Cardiomyopathy Subjects.

As the human thymus ages, it undergoes a transformation into adipose tissue known as TAT. Interestingly, in previous research, we observed elevated levels of vascular endothelial growth factor A (VEGFA) in TAT from patients with ischemic cardiomyopathy (IC), particularly in those over 70 years old. Moreover, in contrast to subcutaneous adipose tissue (SAT), TAT in elderly individuals exhibits enhanced angiogenic properties and the ability to stimulate tube formation. This makes TAT a promising candidate for angiogenic therapies and the regeneration of ischemic tissues following coronary surgery. MicroRNAs (miRNAs) have emerged as attractive therapeutic targets, especially those that regulate angiogenic processes. The study's purpose is to determine the miRNA network associated with both the VEGFA pathway regulation and the enrichment of age-linked angiogenesis in the TAT. RT-PCR was used to analyze angiogenic miRNAs and the expression levels of their predicted target genes in both TAT and SAT from elderly and middle-aged patients treated with coronary artery bypass graft surgery. miRTargetLink Human was used to search for miRNAs and their target genes. PANTHER was used to annotate the biological processes of the predicted targets. The expression of miR-15b-5p and miR-29a-3p was significantly upregulated in the TAT of elderly compared with middle-aged patients. Interestingly, VEGFA and other angiogenic targets were significantly upregulated in the TAT of elderly patients. Specifically: JAG1, PDGFC, VEGFA, FGF2, KDR, NOTCH2, FOS, PDGFRA, PDGFRB, and RHOB were upregulated, while PIK3CG and WNT7A were downregulated. Our results provide strong evidence of a miRNA/mRNA interaction network linked with age-associated TAT angiogenic enrichment in patients with IC.

miR-21 mimic blocks obesity in mice: A novel therapeutic option.

MicroRNAs (miRNAs) are promising drug targets for obesity and metabolic disorders. Recently, miRNA mimics are providing a unique mechanism of action that guides the process for drug development and sets out the context of their therapeutic application. miRNA (miR)-21 expression in white adipose tissue (WAT) has been associated with obesity. We aimed to analyze miR-21 expression levels in relation to diabetes and obesity to determine the effect that miR-21 mimic has on processes involved in WAT functionality, to dissect the underlying molecular mechanisms, and to study the potential therapeutic application of the miR-21 mimic against obesity. We found higher miR-21 levels in WAT from non-diabetic obese compared to normoweight humans and mice. Moreover, in 3T3-L1 adipocytes, miR-21 mimic affect genes involved in WAT functionality regulation and significantly increase the expression of genes involved in browning and thermogenesis. Interestingly, in vivo treatment with the miR-21 mimic blocked weight gain induced by a high-fat diet in obese mice, without modifying food intake or physical activity. This was associated with metabolic enhancement, WAT browning, and brown adipose tissue (AT) thermogenic programming through vascular endothelial growth factor A (VEGF-A), p53, and transforming growth factor ß1 (TGF-ß1) signaling pathways. Our findings suggest that miR-21 mimic-based therapy may provide a new opportunity to therapeutically manage obesity and consequently, its associated alterations.

Angiotensin II induces MMP 2 activity via FAK/JNK pathway in human endothelial cells.

Matrix metalloproteinases (MMPs) play an important role in the pathogenesis of cardiovascular diseases and are modified in response to a variety of stimuli such as bioactive peptides, cytokines and/or grown factors. In this study, we demonstrated that angiotensin II (Ang II) induces a time- and dose-dependent increase in the activity of metalloproteinase 2 (MMP 2) in human umbilical vein endothelial cells (HUVEC). The effect of Ang II was markedly attenuated in cells pretreated with wortmannin and LY294002, two selective inhibitors of phosphatidylinositol-3-kinase (PI3K), indicating that PI3K plays a key role in regulating MMP 2 activity. Similar results were observed when HUVEC were pretreated with genistein, a non-selective tyrosine kinases inhibitor, or with the specific Src-family tyrosine kinase inhibitor PP2, demonstrating the involvement of protein tyrosine kinases, and particularly Src-family tyrosine kinases on the downstream signaling pathway of Ang II receptors. Furthermore, Ang II-induced MMP 2 activation was markedly blocked by SP600125, a selective c-Jun N-terminal kinase (JNK) inhibitor, or pre-treatment of cells with antisense oligonucleotide to focal adhesion kinase (FAK), indicating that both molecules were important for the activation of MMP 2 by Ang II receptor stimulation. In conclusion, these results suggest that Ang II mediates an increase in MMP 2 activity in macrovascular endothelial cells through signal transduction pathways dependent on PI3K and Src-family tyrosine kinases activation, as well as JNK and FAK phosphorylation.

Angiogenic properties of adult human thymus fat.

The endogenous proangiogenic properties of adipose tissue are well recognized. Although the adult human thymus has long been known to degenerate into fat tissue, it has never been considered as a potential source of angiogenic factors. We have investigated the expression of diverse angiogenic factors, including vascular endothelial growth factor A and B, angiopoietin 1, and tyrosine-protein kinase receptor-2 (an angiopoietin receptor), and then analyzed their physiological role on endothelial cell migration and proliferation, two relevant events in angiogenesis. The detection of the gene and protein expression of the various proteins has been performed by immunohistochemistry, Western blotting, and quantitative real-time polymerase chain reaction. We show, for the first time, that adult thymus fat produces a variety of angiogenic factors and induces the proliferation and migration of human umbilical cord endothelial cells. Based on these findings, we suggest that this fat has a potential angiogenic function that might affect thymic function and ongoing adipogenesis within the thymus.

Differences in the neovascular potential of thymus versus subcutaneous adipose-derived stem cells from patients with myocardial ischaemia.

Adipose tissue-derived multipotent mesenchymal cells (ASCs) participate in the information of blood vessels under hypoxic conditions. It is probable that the susceptibility of ASCs to the influence of age and ageing-associated pathologies compromises their therapeutic effectiveness depending on the adipose tissue depot. Our aim was to examine the neovascular potential under hypoxic conditions of ASCs-derived from thymic (thymASCs) and subcutaneous (subASCs) adipose tissue from 39 subjects with and without type 2 diabetes mellitus (T2DM) and of different ages who were undergoing coronary bypass surgery. We confirmed a significant decrease in the percentage of CD34+ CD31- CD45- subASCs in the cell yield of subASCs and in the survival of cultured endothelial cells in the medium conditioned by the hypox-subASCs with increasing patient age, which was not observed in thymASCs. Whereas the length of the tubules generated by hypox-subASCs tended to correlate negatively with patient age, tubule formation capacity of the hypoxic thymASCs increased significantly. Compared with subASCs, thymASCs from subjects over age 65 and without T2DM showed higher cell yield, tubule formation capacity, vascular endothelial growth factor secretion levels, and ability to promote endothelial cell survival in their conditioned medium. Deterioration in subASCs neovascular potential relative to thymASCs derived from these subjects was accompanied by higher expression levels of NOX4 mRNA and fibrotic proteins. Our results indicate that thymASCs from patients over age 65 and without T2DM have a higher angiogenic potential than those from the other patient groups, suggesting they may be a good candidate for angiogenic therapy in subjects undergoing coronary bypass surgery.

Myocardial Ischemic Subject's Thymus Fat: A Novel Source of Multipotent Stromal Cells.

OBJECTIVE: Adipose Tissue Stromal Cells (ASCs) have important clinical applications in the regenerative medicine, cell replacement and gene therapies. Subcutaneous Adipose Tissue (SAT) is the most common source of these cells. The adult human thymus degenerates into adipose tissue (TAT). However, it has never been studied before as a source of stem cells. MATERIAL AND METHODS: We performed a comparative characterization of TAT-ASCs and SAT-ASCs from myocardial ischemic subjects (n = 32) according to the age of the subjects. RESULTS: TAT-ASCs and SAT-ASCs showed similar features regarding their adherence, morphology and in their capacity to form CFU-F. Moreover, they have the capacity to differentiate into osteocyte and adipocyte lineages; and they present a surface marker profile corresponding with stem cells derived from AT; CD73+CD90+CD105+CD14-CD19-CD45-HLA-DR. Interestingly, and in opposition to SAT-ASCs, TAT-ASCs have CD14+CD34+CD133+CD45- cells. Moreover, TAT-ASCs from elderly subjects showed higher adipogenic and osteogenic capacities compared to middle aged subjects, indicating that, rather than impairing; aging seems to increase adipogenic and osteogenic capacities of TAT-ASCs. CONCLUSIONS: This study describes the human TAT as a source of mesenchymal stem cells, which may have an enormous potential for regenerative medicine.

Thymus fat as an attractive source of angiogenic factors in elderly subjects with myocardial ischemia.

Aging negatively affects angiogenesis which is found to be linked to declined vascular endothelial growth factor (VEGF) production. Adult human thymus degenerates into fat tissue (thymus adipose tissue (TAT)). Recently, we described that TAT from cardiomyopathy ischemic subjects has angiogenic properties. The goal of our study was to analyze whether aging could also impair angiogenic properties in TAT as in other adipose tissue such as subcutaneous (subcutaneous adipose tissue (SAT)). SAT and TAT specimens were obtained from 35 patients undergoing cardiac surgery, making these tissues readily available as a prime source of adipose tissue. Patients were separated into two age-dependent groups; middle-aged (n = 18) and elderly (n = 17). Angiogenic, endothelial, and adipogenic expression markers were analyzed in both tissues from each group and correlations were examined between these parameters and also with age. There were no significant differences in subjects from either group in clinical or biological variables. Angiogenic markers VEGF-A, B, C, and D and adipogenic parameters, peroxisome proliferator-activated receptors (PPARγ2), FABP4, and ADRP showed elevated expression levels in TAT from elderly patients compared to the middle-aged group, while in SAT, expression levels of these isoforms were significantly decreased in elderly patients. VEGF-R1, VEGF-R2, VEGF-R3, Thy1, CD31, CD29, and VLA1 showed increased levels in TAT from the elderly compared to the middle-aged, while in SAT these levels displayed a decline with aging. Also, in TAT, angiogenic and endothelial parameters exhibited strong positive correlations with age. TAT appears to be the most appropriate source of angiogenic and endothelial factors in elderly cardiomyopathy subjects compared to SAT.

VEGF gene expression in adult human thymus fat: a correlative study with hypoxic induced factor and cyclooxygenase-2.

UNLABELLED: It is well known that the adult human thymus degenerates into fat tissue; however, it has never been considered as a potential source of angiogenic factors. Recently, we have described that this fat (TAT) produces angiogenic factors and induces human endothelial cell proliferation and migration, indicating its potential angiogenic properties. DESIGN: Adult thymus fat and subcutaneous adipose tissue specimens were obtained from 28 patients undergoing cardiac surgery, making this tissue readily available as a prime source of adipose tissue. We focused our investigation on determining VEGF gene expression and characterizing the different genes, mediators of inflammation and adipogenesis, and which are known to play a relevant role in angiogenesis regulation. RESULTS: We found that VEGF-A was the isoform most expressed in TAT. This expression was accompanied by an upregulation of HIF-1alpha, COX-2 and HO-1 proteins, and by increased HIF-1 DNA binding activity, compared to SAT. Furthermore, we observed that TAT contains a high percentage of mature adipocytes, 0.25% of macrophage cells, 15% of endothelial cells and a very low percentage of thymocyte cells, suggesting the cellular variability of TAT, which could explain the differences in gene expression observed in TAT. Subsequently, we showed that the expression of genes known as adipogenic mediators, including PPARgamma1/gamma2, FABP-4 and adiponectin was similar in both TAT and SAT. Moreover the expression of these latter genes presented a significantly positive correlation with VEGF, suggesting the potential association between VEGF and the generation of adipose tissue in adult thymus. CONCLUSION: Here we suggest that this fat has a potential angiogenic function related to ongoing adipogenesis, which substitutes immune functions within the adult thymus. The expression of VEGF seems to be associated with COX-2, HO-1 and adipogenesis related genes, suggesting the importance that this new fat has acquired in research in relation to adipogenesis and angiogenesis.

Gangrena de Fournier: 10 años de experiencia / Fournier gangrene: a 10 year experience

Introducción: La gangrena de Fournier es una entidad infecciosa caracterizada por una fascitis necrotizante sinérgica rápidamente progresiva a punto de partida urinaria o colorrectal que amenaza la vida del paciente de no instaurarse un diagnóstico temprano y un tratamiento agresivo. Tiene alta prevalencia en pacientes diabéticos e inmunosuprimidos. El objetivo del trabajo es recabar la experiencia de nuestro Servicio y valorar el índice de severidad de gangrena de Fournier en un subgrupo de pacientes. Materiales y métodos: Se realizó un estudio retrospectivo descriptivo que incluyó 52 pacientes que fueron atendidos en el Servicio de Urología del Hospital Ramos Mejía en el período comprendido entre 2000-2009 con diagnóstico de gangrena de Fournier. Se evaluaron los factores predisponentes, el tiempo de evolución, el manejo quirúrgico y la mortalidad. El índice de severidad de gangrena de Fournier se realizó en el subgrupo de los últimos 20 pacientes. Todos los pacientes fueron sometidos a debridamiento quirúrgico y cobertura antibiótica. Resultados: La diabetes como factor predisponente fue identificada en 26/52 pacientes (50 por ciento). La tasa de mortalidad en nuestra serie fue del 11,5 por ciento (6/52). De los 52 pacientes incluidos, en los últimos 20 se utilizó el índice de severidad de gangrena de Fournier. De éstos, 4 presentaron un ISGF >9 puntos con 50 por ciento (2/4) de mortalidad. 49 pacientes fueron sometidos a un único y extenso debridamiento quirúrgico; los otros 3 pacientes requirieron 3 procedimientos quirúrgicos. Al 75 por ciento se les realizó derivación urinaria previo a la cirugía. Conclusión: La gangrena de Fournier es una urgencia urológica. El primer debridamiento quirúrgico debe ser el más agresivo de todos pudiendo disminuir la mortalidad y la necesidad de reintervenciones. Un índice de severidad de gangrena de Fournier >9 puntos se acompaña de una elevada tasa de mortalidad.

Introduction: Fournier gangrene is an infectious entity characterized by a necrotic fascytis or urinary or colonic origin that quickly spreads and may compromise the patient life if not timely treated. It has a high prevalence in diabetic and immunosuppressed patients.Objective: To review the experience gathered at our institution on Fournier gangrene and to evaluate the severity of this situation on a specific subgroup of patients. Material and method: Our retrospective study included 52 patients seen between the year 2000 and 2009 at the Ramos Mejía Hospital with Fournier Gangrene. Associated factors, time of evolution, surgical management and mortality were evaluated. Severity index (SI) was used on the last 20 patients. All patients underwent surgical exploration and antibiotic therapy. Results: Diabetes as predisposing factor was seen in 26 of 52 patients (50 percent). Mortality was 11.5 percent (6 patients). Out of the 20 patients in which SI was used, 4 had SI > 9 with 50 percent mortality. Of the 52 patients, 3 required more than one surgical procedure. All patients underwent urinary diversion prior to surgery. Conclusion: Fournier gangrene is a urological emergency. First surgical intervention should be very aggressive though it may decrease mortality and the need for further interventions. A SI > 9 is associated with higher mortality.

Tiempo de trânsito intestinal en nativos del Altiplano / Intestinal transit time of the Peruvian natives from high lands

En treinta sujetos jóvenes (media=18 años), nativos de Puno (3,850 metros de altura) y que consumen dieta mixta, se estudió el tiempo de tránsito intestinal (TTI) y el peso promedio de sus heces evacuadas en 24 horas (PDH). Para este propósito se utilizó el método de León Barúa y Col. y la fórmula de correlación con el método de Hinton. La media del TTI encontrada (media ñ d.s. = 39.50 ñ 10.04 horas) es menor a las reportadas en otras poblaciones que consumen dieta mixta (p < 0.05). Cuando se compara con poblaciones vegetarianas de medio urbano nuestra cifra es menor (39.50 vs 42.4 Hs); con respecto a grupos rurales con dieta no refinada es mayor (39.17 vs 35.7 Hs). El peso de las heces (PDH) en promedio fué: media ñ d.s. = 327.23 ñ 208.47 gramos en 24 horas, mayor a las encontradas en grupos similares (165 Grs.) o en vegetarianos (225 Grs.); y menor a la de los grupos rurales del Africa (470 Grs.). La correlación entre los TTI y PDH fué negativa (r = 0.441), similar a lo reportado por otros autores. Los resultados obtenidos podrían explicarse por la posibilidad de que algunos componentes de la dieta mixta consumida puedan contribuir con más fibra que la asumida cualitativamente; otro factor a definir es la influencia de la altura sobre el tránsito intestinal