Growth differentiation factor‐15 (GDF‐15) suppresses in vitro angiogenesis through a novel interaction with connective tissue growth factor (CCN2)

Growth differentiation factor‐15 (GDF‐15) and the CCN family member, connective tissue growth factor (CCN2), are associated with cardiac disease, inflammation, and cancer. The precise role and signaling mechanism for these factors in normal and diseased tissues remains elusive. Here we demonstrate an interaction between GDF‐15 and CCN2 using yeast two‐hybrid assays and have mapped the domain of interaction to the von Willebrand factor type C domain of CCN2. Biochemical pull down assays using secreted GDF‐15 and His‐tagged CCN2 produced in PC‐3 prostate cancer cells confirmed a direct interaction between these proteins. To investigate the functional consequences of this interaction, in vitro angiogenesis assays were performed. We demonstrate that GDF‐15 blocks CCN2‐mediated tube formation in human umbilical vein endothelial (HUVEC) cells. To examine the molecular mechanism whereby GDF‐15 inhibits CCN2‐mediated angiogenesis, activation of α_Vβ₃ integrins and focal adhesion kinase (FAK) was examined. CCN2‐mediated FAK activation was inhibited by GDF‐15 and was accompanied by a decrease in α_Vβ₃ integrin clustering in HUVEC cells. These results demonstrate, for the first time, a novel signaling pathway for GDF‐15 through interaction with the matricellular signaling molecule CCN2. Furthermore, antagonism of CCN2 mediated angiogenesis by GDF‐15 may provide insight into the functional role of GDF‐15 in disease states. J. Cell. Biochem. 114: 1424–1433, 2013. © 2012 Wiley Periodicals, Inc.     

The multidisciplinary therapy in binge eating disorder is able to influence the interdaily stability and sleep quality?

ABSTRACT

We have recently shown that rest-activity circadian rhythm significantly differed in women with Binge Eating Disorder (BED) compared to the Ctrl group. In details, patients with BED exhibited significantly reduced levels of MESOR and Amplitude with respect to the Ctrl group. In addition, in this previous study, the results of the actigraphic sleep monitoring provided no evidence of differences in sleep parameters between the two groups. We expanded the original sample obtaining a total of 28 volunteered women, 14 BED women, and 14 Ctrl. We recorded in all 28 participants a 5-day actigraphic monitoring to detect the rhythmometric parameters, interdaily stability, intradaily variability, L5, M10, and sleep parameters. During the study, BED’s women group kept an individual multidisciplinary therapy lasting five weekly days, from Monday to Friday, consisting in cognitive-behavioral therapy and nutritional program, administered in outpatient care from 8:00 a.m. at 5:00 p.m. The combination of both our previous and current study supports the conclusion that the sleep quality of the BED group is significantly better compared to Ctrl. The non-parametric indexes showed how interdaily stability, significantly correlated to sleep efficiency, was higher in BED group compared to the Ctrl group, indicating a better synchronization of rest-activity circadian rhythm. In conclusion, the maintenance of a regular lifestyle, such as imposed by the multidisciplinary therapy, is important to avoid alterations in the sleep-wake cycle, particularly in patients with eating disorders.     

Lymphatic Endothelial Differentiation in Pulmonary Lymphangioleiomyomatosis Cells

Pulmonary lymphangioleiomyomatosis (LAM) is a rare, low-grade neoplasm affecting almost exclusively women of childbearing age. LAM belongs to the family of perivascular epithelioid cell tumors, characterized by spindle and epithelioid cells with smooth muscle and melanocytic differentiation. LAM cells infiltrate the lungs, producing multiple, bilateral lesions rich in lymphatic channels and forming cysts, leading to respiratory insufficiency. Here we used antibodies against four lymphatic endothelial markers—podoplanin (detected by D2-40), prospero homeobox 1 (PROX1), vascular endothelial growth factor receptor 3 (VEGFR-3), and lymphatic vessel endothelial hyaluronan receptor 1 (LYVE1)—to determine whether LAM cells show lymphatic differentiation. Twelve of 12 diagnostic biopsy specimens (early-stage LAM) and 19 of 19 explants (late-stage LAM) showed immunopositivity for D2-40 in most neoplastic cells. PROX1, VEGFR-3, and LYVE1 immunoreactivity varied from scarce in the early stage to abundant in the late stage. Lymphatic endothelial, smooth muscle, and melanocytic markers were partially co-localized. These findings indicate that lymphatic endothelial differentiation is a feature of LAM and provide evidence of a previously unidentified third lineage of differentiation in this neoplasm. This study has implications for the histological diagnosis of LAM, the origin of the neoplastic cells, and potential future treatment with drugs targeting lymphangiogenesis.     

Amphetamine Activates an Amine-gated Chloride Channel to Generate Behavioral Effects in Caenorhabditis elegans

Amphetamine is a highly addictive psychostimulant, which is thought to generate its effects by promoting release of dopamine through reverse activation of dopamine transporters. However, some amphetamine-mediated behaviors persist in dopamine transporter knock-out animals, suggesting the existence of alternative amphetamine targets. Here we demonstrate the identification of a novel amphetamine target by showing that in Caenorhabditis elegans, a large fraction of the behavioral effects of amphetamine is mediated through activation of the amine-gated chloride channel, LGC-55. These findings bring to light alternative pathways engaged by amphetamine, and urge rethinking of the molecular mechanisms underlying the effects of this highly-addictive psychostimulant.     

Characterisation of pks15/1 in clinical isolates of Mycobacterium tuberculosis from Mexico

Tuberculosis (TB) is an infectocontagious respiratory disease caused by members of the Mycobacterium tuberculosis complex. A 7 base pair (bp) deletion in the locus polyketide synthase (pks)15/1 is described as polymorphic among members of the M. tuberculosis complex, enabling the identification of Euro-American, Indo-Oceanic and Asian lineages. The aim of this study was to characterise this locus in TB isolates from Mexico. One hundred twenty clinical isolates were recovered from the states of Veracruz and Estado de Mexico. We determined the nucleotide sequence of a ± 400 bp fragment of the locus pks15/1, while genotypic characterisation was performed by spoligotyping. One hundred and fifty isolates contained the 7 bp deletion, while five had the wild type locus. Lineages X (22%), LAM (18%) and T (17%) were the most frequent; only three (2%) of the isolates were identified as Beijing and two (1%) EAI-Manila. The wild type pks15/1 locus was observed in all Asian lineage isolates tested. Our results confirm the utility of locus pks15/1 as a molecular marker for identifying Asian lineages of the M. tuberculosis complex. This marker could be of great value in the epidemiological surveillance of TB, especially in countries like Mexico, where the prevalence of such lineages is unknown.     

Teaching animal habitat selection using wildlife tracking equipment

We present a hands-on outdoor activity coupled with classroom discussion to teach students about wildlife habitat selection, the process by which animals choose where to live. By selecting locations or habitats with many benefits (e.g., food, shelter, mates) and few costs (e.g., predators), animals improve their ability to survive and reproduce. Biologists track animal movement using radio telemetry technology to study habitat selection so they can better provide species with habitats that promote population growth. We present a curriculum in which students locate “animals” (transmitters) using radio telemetry equipment and apply math skills (use of fractions and percentages) to assess their “animal's” habitat selection by comparing the availability of habitat types with the proportion of “animals” they find in each habitat type.     

Morbidity of Chagas heart disease in the microregion of Rio Negro,Amazonian Brazil: a case-control study

A case-control study on the morbidity of Chagas heart disease was carried out in the municipality of Barcelos in the microregion of the Rio Negro, state of Amazonas. One hundred and six individuals, who were serologically positive for Trypanosoma cruzi infection, as confirmed by at least two techniques with different principles, were matched according to age and sex with an equal number of seronegative individuals. The cases and controls were evaluated using an epidemiological questionnaire and clinical, electrocardiograph and echocardiograph examinations. In the seroepidemiological evaluation, 62% of the interviewees recognised triatomines and most of them confirmed that they had seen these insects in the piassava plantations of the riverside communities of the Negro River tributaries. Of the seropositive patients, 25.8% affirmed that they had been stung by the triatomines and 11.7% denied having been stung. The principal clinical manifestations of the seropositive individuals were palpitations, chest pain and dyspnoea upon effort. Cardiac auscultation revealed extrasystoles, bradycardia and systolic murmurs. The electrocardiographic alterations were ventricular extrasystoles, left and right bundle branch block, atrioventricular block and primary T wave alterations. The echocardiogram was altered in 22.6% of the seropositive individuals and in 8.5% of the seronegative individuals.     

Assessing the impact of thermal acclimation on physiological condition in the zebrafish model

The zebrafish has become a valuable vertebrate model organism in a wide range of scientific disciplines, but current information concerning the physiological temperature response of adult zebrafish is rather scarce. In this study, zebrafish were experimentally acclimated for 28 days to 18, 26 or 34 °C and a suite of non-invasive and invasive methods was applied to determine the thermal dependence of zebrafish physiological condition. With decreasing temperature, the metabolic rate of zebrafish decreased, as shown by the decreasing oxygen uptake and ammonia excretion rates, limiting the critical swimming speed, probably due to a decreased muscle fibre power output. In response to exercise, fuel stores were mobilized to the liver as shown by the increased hepatosomatic index, liver total absolute energetic value and liver carbohydrate concentration but due to the low metabolic rate they could not be adequately addressed to power swimming activity at 18 °C. Conversely, the increased metabolic performance at high temperature came with an increased metabolic cost resulting in decreased energy status reflected particularly well by the non-invasive condition factor and invasive measures of carcass protein concentration, carcass total absolute energetic value and liver carbohydrate concentration. We showed that the combined measurement of the relative condition factor and critical swimming speed is a powerful non-invasive tool for long-term follow-up studies. Invasive methods were redundant for measuring general energy status but they provided detailed information concerning metabolic reorganization. With this study we proved that the usefulness of the zebrafish as a model organism can easily be expanded to include physiological studies and we provided a reference dataset for the selection of measures of physiological responses for future studies using the zebrafish.     

New acritarch species from Holocene sediments in central West Greenland

Anther development, microsporogenesis, and microgametogenesis were studied using both light and TEM microscopy in the six accessible subdioecious/cryptically dioecious species of Consolea (Cactaceae). Anther wall development, microsporogenesis, and microgametogenesis are uniform in staminate flowers of all six species, and are typical for Cactaceae. Breakdown of microsporogenesis in male‐sterile anthers occurs early, at the onset of meiosis, and results in anthers bearing no pollen grains. The abortive process follows a common pattern in all investigated species. The tapetum is the first layer to deviate from normal male‐fertile anther development. Tapetal cells in male‐sterile anthers elongate at an early stage and have abundant rER with atypical configurations. Ultimately, the tapetum becomes hypertrophied and non‐functional. Male‐sterility in pistillate flowers appears to be directly related to these anomalies. In addition, other anther layers and tissues are affected, and normal patterns of programmed cell death (PCD) are disrupted. The relationship between these patterns and the pattern of PCD in normal male‐fertile anthers is discussed. We hypothesize a single origin for the cryptically dioecious/subdioecious breeding system of Consolea based on the uniformity of the anther's abortive processes in pistillate flowers.     

Fluorescent ligands for adenosine receptors

Interest is increasing in developing fluorescent ligands for characterization of adenosine receptors (ARs), which hold a promise of usefulness in the drug discovery process. The size of a strategically labeled AR ligand can be greatly increased after the attachment of a fluorophore. The choice of dye moiety (e.g. Alexa Fluor 488), attachment point and linker length can alter the selectivity and potency of the parent molecule. Fluorescent derivatives of adenosine agonists and antagonists (e.g. XAC and other heterocyclic antagonist scaffolds) have been synthesized and characterized pharmacologically. Some are useful AR probes for flow cytometry, fluorescence correlation spectroscopy, fluorescence microscopy, fluorescence polarization, fluorescence resonance energy transfer, and scanning confocal microscopy. Thus, the approach of fluorescent labeled GPCR ligands, including those for ARs, is a growing dynamic research field.