Reduced Angiopoietin Factor 2 Levels Are Correlated with Better Cardiac Function and Prognosis in Valvular Heart Disease.

INTRODUCTION: There are few circulating biomarkers for valvular heart disease. Angiopoietin (Ang) 1, Ang2, and vascular endothelial growth factor are important inflammation-associated cytokines. The aim of this study was to investigate the clinical significance and association of Ang1, Ang2, and vascular endothelial growth factor in valvular heart disease. METHODS: This is a retrospective study; a total of 62 individuals (valvular heart disease patients [n=42] and healthy controls [n=20]) were included. Plasma levels of Ang1, Ang2, and vascular endothelial growth factor were detected by enzyme-linked immunosorbent assays. We retrospectively collected the baseline characteristics and short-term outcomes; logistic regression was performed to identify predictor for short-term mortality. RESULTS: Ang2 was significantly decreased in the valvular heart disease group compared with the healthy control group (P=0.023), while no significant difference was observed in the Ang1 and vascular endothelial growth factor levels. The Ang2 level of New York Heart Association (NYHA) I/II patients - but not NYHA III/IV patients - was significantly decreased compared with that of healthy control individuals (NYHA I/II: P=0.017; NYHA III/IV: P=0.485). Univariable logistic regression analysis indicated that Ang2 was a significant independent predictor for short-term mortality (odds ratio 18.75, P=0.033, 95% confidence interval 8.08-102.33). Ang1 was negatively correlated with Ang2 (P=0.032, Pearson's correlation coefficient =-0.317) and was positively correlated with vascular endothelial growth factor (P=0.019, Pearson's correlation coefficient = 0.359). CONCLUSION: Ang2 might serve as a therapeutic and prognostic target for valvular heart disease.

Paricalcitol Improves the Angiopoietin/Tie-2 and VEGF/VEGFR2 Signaling Pathways in Adriamycin-Induced Nephropathy.

Renal endothelial cell (EC) injury and microvascular dysfunction contribute to chronic kidney disease (CKD). In recent years, increasing evidence has suggested that EC undergoes an endothelial-to-mesenchymal transition (EndoMT), which might promote fibrosis. Adriamycin (ADR) induces glomerular endothelial dysfunction, which leads to progressive proteinuria in rodents. The activation of the vitamin D receptor (VDR) plays a crucial role in endothelial function modulation, cell differentiation, and suppression of the expression of fibrotic markers by regulating the production of nitric oxide (NO) by activating the endothelial NO synthase (eNOS) in the kidneys. This study aimed to evaluate the effect of paricalcitol treatment on renal endothelial toxicity in a model of CKD induced by ADR in rats and explore mechanisms involved in EC maintenance by eNOS/NO, angiopoietins (Angs)/endothelium cell-specific receptor tyrosine kinase (Tie-2, also known as TEK) and vascular endothelial growth factor (VEGF)-VEGF receptor 2 (VEGFR2) axis. The results show that paricalcitol attenuated the renal damage ADR-induced with antiproteinuric effects, glomerular and tubular structure, and function protection. Furthermore, activation of the VDR promoted the maintenance of the function and structure of glomerular, cortical, and external medullary endothelial cells by regulating NO production. In addition, it suppressed the expression of the mesenchymal markers in renal tissue through attenuation of (transforming growth factor-beta) TGF-ß1/Smad2/3-dependent and downregulated of Ang-2/Tie-2 axis. It regulated the VEGF/VEGFR2 pathway, which was ADR-deregulated. These effects were associated with lower AT1 expression and VDR recovery to renal tissue after paricalcitol treatment. Our results showed a protective role of paricalcitol in the renal microvasculature that could be used as a target for treating the beginning of CKD.

Study of angiopoietin and plasminogen genes in hereditary angioedema.

OBJECTIVE: To investigate the presence of the Angiopoietin 1 (ANGPT1) and Plasminogen (PLG) mutations in patients with Hereditary Angioedema (HAE) and normal C1 esterase inhibitor (C1-INH) levels, who do not harbor the F12 gene mutation. METHODS: Patients clinically diagnosed with HAE but without C1-INH deficiency or dysfunction and F12 gene mutation were evaluated. DNA extraction, quantification, and dilution were performed at a concentration of 100 ng/µL, followed by a DNA amplification (PCR) for molecular evaluation of exon 2 of the ANGPT1 gene and exon 9 of the PLG gene for identification of mutations c.807G>T / p.A119S and c.988A>G / p.K330E, respectively. The PCR product was evaluated in 1% agarose gel electrophoresis. Sequencing was performed using the Sanger method. The electropherograms were analyzed using the FASTA® program. RESULTS: DNA samples from 15 women were sequenced. Their ages ranged from 10 to 60 years and the normal C1 esterase and C4 inhibitor serum levels ranged from 22 to 39 mg/dL and from 10 to 40 mg/dL, respectively. No mutations were detected in the analyzed exons of ANGPT1 and PLG. However, a single-nucleotide polymorphism (SNP) was detected in two homozygotic and five heterozygotic patients. CONCLUSION: Further studies are needed to evaluate these SNPs and scrutinize their potential for use as molecular markers of HAE and as novel therapeutic targets.

Study of angiopoietin and plasminogen genes in hereditary angioedema

SUMMARY OBJECTIVE To investigate the presence of the Angiopoietin 1 (ANGPT1) and Plasminogen (PLG) mutations in patients with Hereditary Angioedema (HAE) and normal C1 esterase inhibitor (C1-INH) levels, who do not harbor the F12 gene mutation. METHODS Patients clinically diagnosed with HAE but without C1-INH deficiency or dysfunction and F12 gene mutation were evaluated. DNA extraction, quantification, and dilution were performed at a concentration of 100 ng/µL, followed by a DNA amplification (PCR) for molecular evaluation of exon 2 of the ANGPT1 gene and exon 9 of the PLG gene for identification of mutations c.807G>T / p.A119S and c.988A>G / p.K330E, respectively. The PCR product was evaluated in 1% agarose gel electrophoresis. Sequencing was performed using the Sanger method. The electropherograms were analyzed using the FASTA® program. RESULTS DNA samples from 15 women were sequenced. Their ages ranged from 10 to 60 years and the normal C1 esterase and C4 inhibitor serum levels ranged from 22 to 39 mg/dL and from 10 to 40 mg/dL, respectively. No mutations were detected in the analyzed exons of ANGPT1 and PLG. However, a single-nucleotide polymorphism (SNP) was detected in two homozygotic and five heterozygotic patients. CONCLUSION Further studies are needed to evaluate these SNPs and scrutinize their potential for use as molecular markers of HAE and as novel therapeutic targets.

RESUMO OBJETIVO Investigar a presença das mutações no gene Angiopoietina (ANGPT1) e gene Plasminogênio (PLG) em pacientes com Angioedema Hereditário (AEH) com inibidor C1 esterase (C1-INH) normal e negativos para mutação do gene F12. MÉTODOS Foram avaliados pacientes com diagnóstico clínico de AEH sem deficiência ou disfunção de C1-INH e negativos para mutação do gene F12. Realizou-se extração, quantificação e diluição do DNA a uma concentração de 100 ng/uL, em seguida amplificação do DNA (PCR) para avaliação molecular do exon 2 do gene ANGPT1 e do exon 9 do gene PLG para identificação das mutações c.807G>T.p.A119S e c.988A>G p.K330E, respectivamente. O produto da PCR foi avaliado em eletroforese em gel de agarose 1%. Foi realizado o sequenciamento pelo método de Sanger. As análises dos eletroferogramas foram realizadas pelo programa FASTA®. RESULTADOS Foram sequenciadas amostras de 15 mulheres, idade entre 10 e 60 anos, com níveis séricos de inibidor de C1 esterase e C4 normais variando de 22 a 39mg/dL e 10 a 40mg/dL, respectivamente. Não foram identificadas mutações nos éxons analisados dos genes ANGPT1 e PLG. Entretanto no gene PLG foram encontrados polimorfismo de nucleotídeo único (SNP), em duas pacientes homozigotas e cinco heterozigotas. CONCLUSÃO Mais estudos sobre SNP são necessários para esclarecer estes achados pois eles podem ser utilizados como marcadores moleculares do AEH e alvo para novos tratamentos.

Angiopoetin-like 4 in sickle cell retinopathy.

This correspondence provides a comment on the recent review article by Yang et al. [Biosci. Rep. (2018) 38, BSR20180557, https://doi.org/10.1042/BSR20180557].

Excess Maternal Thyroxine Alters the Proliferative Activity and Angiogenic Profile of Growth Cartilage of Rats at Birth and Weaning.

Objective The aim of this study was to unravel the mechanisms by which thyroxine affects skeletal growth by evaluating proliferative activity and angiogenic profile of growth cartilage of neonatal and weanling rats. Methods Sixteen adult Wistar rats were equally divided into 2 groups: control and treated with thyroxine during pregnancy and lactation. The weight, measurement of plasma free T4 and thyroids, femurs' histomorphometric analysis, and proliferative activity and angiogenic profile by immunohistochemical or real-time reverse transcriptase-polymerase chain reaction in growth cartilage was performed. Data were analyzed using Student's t test. Results The free T4 was significantly higher in the treated rats. However, the height of the follicular epithelium of the thyroid in newborns was significantly lower in the treated group. The excess maternal thyroxine significantly reduced the body weight and length of the femur in the offspring but significantly increased the thickness of trabecular bone and changed the height of the zones of the growth plate. Furthermore, excess maternal thyroxine reduced cell proliferation and vascular endothelial growth factor (VEGF) expression in the growth cartilage of newborn and 20-day-old rats ( P < 0.05). There was also a reduction in the immunohistochemical expression of Tie2 in the cartilaginous epiphysis of the newborns and FLK-1 in the articular cartilage of 20-day-old rats. No significant difference was observed in Ang2 expression. Conclusions The excess maternal thyroxine during pregnancy and lactation reduced endochondral bone growth in the progeny and reduced the proliferation rate and VEGF, Flk-1, and Tie2 expression in the cartilage of growing rats without altering the mRNA expression of Ang1 and Ang2.

Effects of sleeve gastrectomy and rs9930506 FTO variants on angiopoietin/Tie-2 system in fat expansion and M1 macrophages recruitment in morbidly obese subjects.

Angiogenesis in inflammation are hallmarks for adipose tissue expansion in obesity. The role of angiopoietin/Tie-2 system in adipose tissue expansion and immune cell recruitment is unclear. We studied the effect of sleeve gastrectomy and the influence of FTO rs9930506 polymorphism on Tie-2, angiopoietin-1 and angiopoietin-2 expression in morbid obesity. Fifteen morbidly obese subjects (4 men and 11 women) aged 24-55 years were followed-up 3 and 6 months after sleeve gastrectomy. Serum sTie-2, angiopoietin-1, angiopoietin-2, and hypoxia-inducible factor-1α concentrations were determined by ELISA. Tie-2 and its ligands in visceral and subcutaneous adipose tissue were localized by immunohistochemistry. Tie-2 expression was measured by flow cytometry in circulating monocytes and infiltrated macrophages. Comparisons before and after sleeve gastrectomy were carried out using ANOVA for repeated measures. rs9930506FTO genotyping was performed by PCR-RFLP. Circulating sTie-2 and angiopoietin-2 were higher before sleeve gastrectomy. Tie-2 and angiopoietin-2 mRNA levels were higher in subcutaneous adipose tissue than visceral and both decreased after surgery. Monocytes and infiltrated macrophages showed a pro-inflammatory phenotype, with increased Tie-2 expression that decreased 3 and 6 months after sleeve gastrectomy. Baseline sTie-2 correlated inversely with adiponectin levels. At baseline the rs9930506FTO AG ó GG genotypes carriers had more 34 kg than genotype carriers of rs9930506 AA. Weight and body mass index decreased at 6 months. We found that angiopoietin/Tie-2 system is mainly expressed in subcutaneous adipose tissue, contributing to expandability, fat accumulation, and monocytes attachment in obesity. Bariatric surgery favorably modifies the pro-angiogenic profile, allowed a reduced angiogenic expression in the circulation and adipose tissue.

Cancer as a Proinflammatory Environment: Metastasis and Cachexia.

The development of the syndrome of cancer cachexia and that of metastasis are related with a poor prognostic for cancer patients. They are considered multifactorial processes associated with a proinflammatory environment, to which tumour microenvironment and other tissues from the tumour bearing individuals contribute. The aim of the present review is to address the role of ghrelin, myostatin, leptin, HIF, IL-6, TNF-α, and ANGPTL-4 in the regulation of energy balance, tumour development, and tumoural cell invasion. Hypoxia induced factor plays a prominent role in tumour macro- and microenvironment, by modulating the release of proinflammatory cytokines.

[Intestinal microbiota and cardiometabolic risk: mechanisms and diet modulation]. / Microbiota intestinal e risco cardiometabólico: mecanismos e modulação dietética.

The gut microbiota obtained after birth is composed of a large range of bacteria that play different roles in the human host, such as nutrient uptake, protection against pathogens and immune modulation. The intestinal bacterial content is not completely known, but it is influenced by internal, and mainly by external factors, which modulate its composition and function. Studies indicate that the gut microbiota differs in lean and obese individuals, and in individuals with different food habits. There is evidence that the relationship between diet, inflammation, insulin resistance, and cardiometabolic risk are, in part, mediated by the composition of intestinal bacteria. Knowledge about the gut microbiota may result in different strategies to manipulate bacterial populations and promote health. This review discusses the relevance of understanding the role of dietary factors or patterns in the composition of the microbiota, as well as pathophysiological mechanisms of chronic metabolic diseases, and the potential of prebiotics and probiotics on the cardiometabolic risk profile.

Microbiota intestinal e risco cardiometabólico: mecanismos e modulação dietética / Intestinal microbiota and cardiometabolic risk: mechanisms and diet modulation

A microbiota intestinal, adquirida no período pós-natal, é composta por grande diversidade de bactérias que desempenham diferentes funções no hospedeiro humano, entre elas a absorção de nutrientes, proteção contra patógenos e modulação do sistema imune. O conteúdo bacteriano intestinal ainda não é totalmente conhecido, mas sabe-se que é influenciado por fatores internos e principalmente externos que modulam sua composição e função. Estudos indicam que a microbiota intestinal difere em indivíduos magros e obesos e ainda naqueles que mantêm hábitos alimentares diferentes. Há evidências de que as relações entre dieta, inflamação, resistência à insulina e risco cardiometabólico são em parte mediadas pela composição de bactérias intestinais. Conhecimentos sobre a microbiota poderão reverter em diferentes estratégias para manipular as populações bacterianas e promover saúde. Esta revisão aborda a relevância do conhecimento sobre o papel de fatores ou padrões alimentares na composição da microbiota, assim como mecanismos fisiopatológicos de doenças metabólicas crônicas e as potencialidades de prebióticos e probióticos sobre o perfil de risco cardiometabólico.

The gut microbiota obtained after birth is composed of a large range of bacteria that play different roles in the human host, such as nutrient uptake, protection against pathogens and immune modulation. The intestinal bacterial content is not completely known, but it is influenced by internal, and mainly by external factors, which modulate its composition and function. Studies indicate that the gut microbiota differs in lean and obese individuals, and in individuals with different food habits. There is evidence that the relationship between diet, inflammation, insulin resistance, and cardiometabolic risk are, in part, mediated by the composition of intestinal bacteria. Knowledge about the gut microbiota may result in different strategies to manipulate bacterial populations and promote health. This review discusses the relevance of understanding the role of dietary factors or patterns in the composition of the microbiota, as well as pathophysiological mechanisms of chronic metabolic diseases, and the potential of prebiotics and probiotics on the cardiometabolic risk profile.

Differential expression and effect of the porcine ANGPTL4 gene on intramuscular fat.

In a previous study, we investigated differences in gene expression in backfat between Meishan and Large White pigs and their F1 hybrids, Large White x Meishan, and Meishan x Large White pigs. One potential differentially expressed sequence tag from the mRNA differential display was a homolog of the human angiopoietin-like 4 (ANGPTL4) gene, which encodes a protein that is secreted by both liver and white adipose tissues and can inhibit lipoprotein lipase activity and stimulate white adipose tissue lipolysis. Here, ANGPTL4 mRNA was found to be upregulated in the backfat of Large White compared with that in the Meishan pigs and the F1 hybrids, Meishan x Large White and Large White x Meishan, whereas expression was lowest both in the longissimus dorsi and the heart, as shown by the tissue distribution profile. Only one mutation, a G/A transition located in the third intron, was found. The ANGPTL4 G/A polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) showed a significant effect on intramuscular fat (IMF), water moisture of the longissimus dorsi, meat marbling of the longissimus dorsi, and pH of the longissimus dorsi (P < 0.05). This site seemed to be significantly (P < 0.05) additive in its actions on IMF, water moisture, and pH, whereas it showed significant dominance in its action on meat marbling (P < 0.05). This locus can be potentially considered as a marker for IMF improvement.

Genetic and environmental determinants of the susceptibility of Amerindian derived populations for having hypertriglyceridemia.

Here, we discuss potential explanations for the higher prevalence of hypertriglyceridemia in populations with an Amerindian background. Although environmental factors are the triggers, the search for the ethnic related factors that explain the increased susceptibility of the Amerindians is a promising area for research. The study of the genetics of hypertriglyceridemia in Hispanic populations faces several challenges. Ethnicity could be a major confounding variable to prove genetic associations. Despite that, the study of hypertriglyceridemia in Hispanics has resulted in significant contributions. Two GWAS reports have exclusively included Mexican mestizos. Fifty percent of the associations reported in Caucasians could be generalized to the Mexicans, but in many cases the Mexican lead SNP was different than that reported in Europeans. Both reports included new associations with apo B or triglycerides concentrations. The frequency of susceptibility alleles in Mexicans is higher than that found in Europeans for several of the genes with the greatest effect on triglycerides levels. An example is the SNP rs964184 in APOA5. The same trend was observed for ANGPTL3 and TIMD4 variants. In summary, we postulate that the study of the genetic determinants of hypertriglyceridemia in Amerindian populations which have major changes in their lifestyle, may prove to be a great resource to identify new genes and pathways associated with hypertriglyceridemia.

Vascular permeability changes involved in tumor metastasis.

Cancer cell extravasation resembles the leukocyte recruitment during inflammation. Evidence suggests that cancer cells need to weaken the interendothelial junctions in order to cross the endothelial barrier. Several tumor-derived vasoactive compounds have been pointed out to drive this increase in vascular permeability: VEGF, Angptl4, CCL2, SDF-1, etc. Therefore, tumor cells have a wide repertoire of soluble factors to increase vascular permeability in order to colonize new tissues. Tumor soluble factors activate different signaling pathways to induce interendothelial junction disassembly, one common element is Src kinase. Here we summarize the relevant current knowledge about vascular permeability changes involved in tumor metastasis.

Avaliação clínica de proteínas modeladoras da permeabilidade endotelial como biomarcadores para estratificação de risco na sepse em pacientes com neoplasias hematológicas e neutropenia febril / Clinical evaluation of modulators of endothelial permeability as biomarkers for risk stratification in sepsis patients with hematological malignancies and febrile neutropenia

A neutropenia febril (NF) em pacientes com neoplasias hematológicas é caracterizada pelo alto risco de sepse e choque séptico. Embora a utilização de escores clínicos como o MASCC permita a identificação de pacientes de baixo risco, este escore é menos informativo em pacientes de alto risco, onde se encaixam a maioria dos pacientes com neoplasias hematológicas, além daqueles submetidos a esquemas intensivos de quimioterapia. Ao mesmo tempo, a aplicação de biomarcadores de gravidade como a procalcitonina, validados em pacientes não-neutropênicos, é controversa em pacientes com NF. A quebra da barreira endotelial é um elemento chave no choque séptico, de modo que proteínas envolvidas neste processo são candidatos atrativos como biomarcadores de gravidade na sepse. Neste estudo, avaliamos prospectivamente o valor da dosagem de VEGF-A, sFlt-1, Ang-1 e Ang-2 como biomarcadores da evolução para choque séptico em 120 pacientes com NF. Pacientes internados nas enfermarias de Hematologia e Transplante de Medula Óssea do HC da UNICAMP para tratamento de NF entre março de 2011 e 2012 foram convidados a participar. As amostras foram coletadas na manhã seguinte à entrada no estudo, junto com a coleta de exames de rotina. O estudo foi desenhado com o objetivo de mimetizar as condições de coleta e processamento das amostras, que seriam encontradas na prática clínica real. Foi avaliada a evolução para choque séptico e mortalidade em 28 dias. Os resultados foram comparados com marcadores de prognóstico clássicos como proteína C reativa, e escores MASCC e SOFA. No total, 99 pacientes preencheram os critérios de inclusão, dos quais 19,8% evoluíram com choque séptico. Não foram observadas diferenças clínicas e demográficas entre os pacientes com NF não-complicada e choque séptico, exceto pelo escore SOFA, significativamente mais elevado no segundo grupo.

Febrile neutropenia (FN) in patients with hematologic malignancies is characterized by a high risk of sepsis complications and septic shock. Although the use of clinical scores such as the MASCC allows the identification of low-risk patients, this score is much less informative in high-risk patients, a category in which most patients with hematologic malignancies, and those undergoing intensive chemotherapy regimens, fit in. At the same time, the use of classical biomarkers such as procalcitonin in non-neutropenic patients is controversial in patients with FN. Endothelial barrier breakdown is a key element in septic shock, so that proteins involved in this process are attractive candidates as biomarkers of sepsis severity. In this study, we prospectively evaluated the value of VEGF-A, sFlt-1, Ang-1 and Ang-2 serum levels as biomarkers of progression to septic shock in 120 patients with FN. Patients hospitalized in the Hematology and Bone Marrow Transplantation in-patient units of a university hospital (HC-UNICAMP) for the treatment of FN between March 2011 and March 2012 were invited to participate. Samples were collected in the following morning after study entry, along with the collection of routine labs. The study was designed to mimic the conditions of blood sample collection and processing that would be encountered in "real-world" clinical practice. Clinical outcomes were (1) progression to septic shock and (2) death within 28 days from fever onset. Results were compared with classical prognostic markers such as C-reactive protein, and MASCC and SOFA scores. In total, 99 patients met the inclusion criteria, of which 19.8% progressed to septic shock. No differences clinical and demographic differences were observed between patients with uncomplicated-FN or septic shock, except for a higher SOFA scores in the latter group.

Angiopoietins/TIE2 system and VEGF are involved in ovarian function in a DHEA rat model of polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is the most common endocrinological pathology among women of reproductive age. It is characterized by anovulation, oligo- or amenorrhea, hyperandrogenism, obesity, and insulin resistance. PCOS patients present with elevated levels of vascular endothelial growth factor (VEGF) in serum and follicular fluid. In this study, we examined the ovarian expression of angiopoietins (ANGPT) and their receptor tyrosine kinase receptor (TIE2), involved in the stabilization of blood vessels, in a rat model of dehydroepiandrosterone-induced PCOS. We also analyzed the effect of ovarian VEGF inhibition on ANGPT/TIE2, follicular development, and vascular stability. VEGF levels were increased in the PCOS ovaries, whereas the levels of its receptor fetal liver kinase-1 were decreased. In addition, the periendothelial cell area and the ANGPT1 to ANGPT2 ratio in the ovary were increased in the PCOS group. Percentage of primary follicles was increased and the percentage of preantral follicles and corpora lutea was decreased in the PCOS group. VEGF inhibition decreased the percentage of primary follicles close to control values. Interestingly, despite the presence of cysts in the ovaries from VEGF inhibitor-treated PCOS rats, its percentage was lower than the PCOS group without treatment. In summary, this study describes an alteration not only in the VEGF/fetal liver kinase-1 system but also in the ANGPT/TIE2 system in a dehydroepiandrosterone-induced PCOS rat model. This leads to an increase in periendothelial cell recruitment. We also demonstrated that ovarian VEGF inhibition can partially restore the accumulation of small follicles in PCOS rats and reduces cyst formation, improving ovulation and follicular development. Therefore, the inhibition of VEGF could be considered, in addition to other currently applied treatments, as a new strategy to be studied in PCOS patients to restore ovarian function.