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101.
Joan Domingo-Espín Oktawia Nilsson Katja Bernfur Rita Del Giudice Jens O. Lagerstedt 《生物化学与生物物理学报:疾病的分子基础》2018,1864(9):2822-2834
Prolonged hyperglycemia in poorly controlled diabetes leads to an increase in reactive glucose metabolites that covalently modify proteins by non-enzymatic glycation reactions. Apolipoprotein A-I (apoA-I) of high-density lipoprotein (HDL) is one of the proteins that becomes glycated in hyperglycemia. The impact of glycation on apoA-I protein structure and function in lipid and glucose metabolism were investigated.ApoA-I was chemically glycated by two different glucose metabolites (methylglyoxal and glycolaldehyde). Synchrotron radiation and conventional circular dichroism spectroscopy were used to study apoA-I structure and stability. The ability to bind lipids was measured by lipid-clearance assay and native gel analysis, and cholesterol efflux was measured by using lipid-laden J774 macrophages. Diet induced obese mice with established insulin resistance, L6 rat and C2C12 mouse myocytes, as well as INS-1E rat insulinoma cells, were used to determine in vivo and in vitro glucose uptake and insulin secretion.Site-specific, covalent modifications of apoA-I (lysines or arginines) led to altered protein structure, reduced lipid binding capability and a reduced ability to catalyze cholesterol efflux from macrophages, partly in a modification-specific manner. The stimulatory effects of apoA-I on the in vivo glucose clearance were negatively affected when apoA-I was modified with methylglyoxal, but not with glycolaldehyde. The in vitro data showed that both glucose uptake in muscle cells and insulin secretion from beta cells were affected. Taken together, glycation modifications impair the apoA-I protein functionality in lipid and glucose metabolism, which is expected to have implications for diabetes patients with poorly controlled blood glucose. 相似文献
102.
FABIANY DA COSTA GONÇALVES MICHELE ARAMBURU SERAFINI HELENA FLORES MELLO BIANCA PFAFFENSELLER ANELISE BERGMANN ARAÚJO FERNANDA VISIOLI ANA HELENA PAZ 《Cytotherapy》2018,20(12):1459-1471
Background aims
Although mesenchymal stromal cells (MSCs) have shown therapeutic potential in intestinal tissue repair, controversy concerning their short survival and poor biodistribution in recipient tissues still remains. Therefore, we investigated the paracrine role of MSC in three-dimensional culture of colon with experimental colitis.Methods
Colitis was induced in mice by oral administration of dextran sulfate sodium (DSS) for 7 days. Inflammatory responses were assessed on the basis of clinical signs, morphological, and histopathological parameters. On days 2 and 5, colonic explants were removed, and a three-dimensional culture was performed. The structural integrity of the intestinal mucosa was tested by treating the cultures with MSC or conditioned medium (CM) for 24 h, and then the colons were analyzed for histology/immunohistochemistry and interleukin (IL)-6 production.Results
Histological analysis demonstrated that both MSC and CM treatment reduced colon damage in organ culture. An increase in cell proliferation (Ki-67 staining) was observed after CM treatment. Additionally, MSC treatment was able to reduce CD3+ cells. The therapeutic effect of MSC and CM was mediated by the downregulation of IL-6.Discussion
The intestinal in vitro model has shown to be potentially useful for studying cellular interactions in a three-dimensional cell arrangement. Moreover, our results provide strong evidence that both MSC and CM treatments can alleviate colonic damage in organ culture. Importantly, these results suggest that MSC-secreted factors are able to protect the colon from inflammation caused by DSS-induced colitis independent of cell transplantation. 相似文献103.
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105.
The endemic stingless honey‐making bee Melipona (Melikerria) insularis sp.n. on Coiba and Ranchería Islands in Pacific Panama is described, together with the proposed sister species, M. ambigua sp.n. from northeast Colombia. The Coiba Island group and Panama mainland were surveyed, yielding one meliponine endemic (M. insularis sp.n. ) and six meliponine genera and species. The poor Coiba fauna of amphibians and birds corresponds to the poor social bee fauna and suggests habitat barriers generally precluded recolonization from the mainland during glacial periods. Many animals became extinct, yet some remain as relicts. Melipona insularis sp.n. was isolated on accreted terranes of Coiba rainforest in the Panama microplate. Morphology suggests that M. insularis sp.n. is not a direct descendant of the San Blas‐E. Panama endemic Melikerria, M. triplaridis. A phylogenetic hypothesis corroborates disjunct distributions. Rainforest endemics such as Peltogyne purpurea (Fabaceae) and Ptilotrigona occidentalis (Apidae, Meliponini) also occur as relictual, disjunct populations in Central and South America. These may have been isolated before accelerated biotic exchange began 2.4 Ma. Our work supports the geological findings of both a volcanic arc and the San Blas massif providing a substantial bridge for Melikerria from Colombia and Panama in Eocene to Miocene times. We suggest there have been taxon cycles permitting recolonization during glaciations, whereby colonies of M. insularis sp.n. were able to recolonize Ranchería, a 250 ha island, 2 km from Coiba. However, rafting colonies nesting in trees, carried on vegetation mats, may have produced founding populations of Melipona in Central America and on oceanic islands such as Coiba. 相似文献
106.
TORBEN DABELSTEEN PETER K. McGREGOR HELENE M. LAMPE NAOMI E. LANGMORE JO HOLLAND 《Bioacoustics.》2013,22(2):89-105
ABSTRACT The theory of communication networks offers functional arguments for the evolution of unobtrusive signals in birds. The vulnerability of interacting conspecifics to predation and to eavesdropping by neighbours during both territorial disputes and courtship would select for short range signals such as the quiet songs of birds. In addition to suggesting contexts in which quiet songs should be used, we use our knowledge of the physics of sound transmission to make predictions about the physical structure of such songs relative to the well studied full songs. We present support for these predictions in six species where quiet singing has been observed. 相似文献
107.
108.
Synergism of thymol,carvacrol and eugenol in larvae of the cattle tick,Rhipicephalus microplus,and brown dog tick,Rhipicephalus sanguineus 下载免费PDF全文
L. X. ARAÚJO T. P. L. NOVATO V. ZERINGOTA R. MATURANO D. MELO B. C. DA SILVA E. DAEMON M. G. DE CARVALHO C. M. O. MONTEIRO 《Medical and veterinary entomology》2016,30(4):377-382
The effects of combinations of the monoterpenes thymol and carvacrol and the phenylpropanoid eugenol in larvae of Rhipicephalus microplus (Canestrini, 1888) (Acari: Ixodidae) and Rhipicephalus sanguineus sensu lato (s.l.) (Acari: Ixodidae) were assessed by the larval packet test. The CompuSyn program was used to make qualitative assessments of the effects (synergistic, additive and antagonistic) of the associations. The effects of all combinations tested against R. microplus larvae were synergistic, with combination indices (CIs) <0.70. When tested against R. sanguineus, eight of the mixtures showed a synergistic effect (CI < 0.70); only the carvacrol + thymol mixture at LC50 presented a moderate synergistic effect, with CIs between 0.70–0.90. This study is the first to determine the effects of the interactions of these substances in the control of these two tick species. The combinations of carvacrol + thymol, carvacrol + eugenol and thymol + eugenol have synergistic effects in R. microplus and R. sanguineus s.l. larvae. 相似文献
109.
Utilizing systems biology to unravel stomatal function and the hierarchies underpinning its control 下载免费PDF全文
DAVID B. MEDEIROS DANILO M. DALOSO ALISDAIR R. FERNIE ZORAN NIKOLOSKI WAGNER L. ARAÚJO 《Plant, cell & environment》2015,38(8):1457-1470
Stomata control the concomitant exchange of CO2 and transpiration in land plants. While a constant supply of CO2 is need to maintain the rate of photosynthesis, the accompanying water losses must be tightly regulated to prevent dehydration and undesired metabolic changes. The factors affecting stomatal movement are directly coupled with the cellular networks of guard cells. Although the guard cell has been used as a model for characterization of signaling pathways, several important questions about its functioning remain elusive. Current modeling approaches describe the stomatal conductance in terms of relatively few easy‐to‐measure variables being unsuitable for in silico design of genetic manipulation strategies. Here, we argue that a system biology approach, combining modeling and high‐throughput experiments, may be used to elucidate the mechanisms underlying stomata control and to determine targets for modulation of stomatal responses to environment. In support of our opinion, we review studies demonstrating how high‐throughput approaches have provided a systems‐view of guard cells. Finally, we emphasize the opportunities and challenges of genome‐scale modeling and large‐scale data integration for in silico manipulation of guard cell functions to improve crop yields, particularly under stress conditions which are of pertinence both to climate change and water use efficiency. 相似文献
110.
ROBIN ENGLER CHRISTOPHE F. RANDIN WILFRIED THUILLER STEFAN DULLINGER NIKLAUS E. ZIMMERMANN MIGUEL B. ARAÚJO PETER B. PEARMAN GWENAËLLE LE LAY CHRISTIAN PIEDALLU CÉCILE H. ALBERT PHILIPPE CHOLER GHEORGHE COLDEA XAVIER
De LAMO THOMAS DIRNBÖCK JEAN‐CLAUDE GÉGOUT DANIEL GÓMEZ‐GARCÍA JOHN‐ARVID GRYTNES EINAR HEEGAARD FRIDE HØISTAD DAVID NOGUÉS‐BRAVO SIGNE NORMAND MIHAI PUŞCAŞ MARIA‐TERESA SEBASTIÀ ANGELA STANISCI JEAN‐PAUL THEURILLAT MANDAR R. TRIVEDI PASCAL VITTOZ ANTOINE GUISAN 《Global Change Biology》2011,17(7):2330-2341
Continental‐scale assessments of 21st century global impacts of climate change on biodiversity have forecasted range contractions for many species. These coarse resolution studies are, however, of limited relevance for projecting risks to biodiversity in mountain systems, where pronounced microclimatic variation could allow species to persist locally, and are ill‐suited for assessment of species‐specific threat in particular regions. Here, we assess the impacts of climate change on 2632 plant species across all major European mountain ranges, using high‐resolution (ca. 100 m) species samples and data expressing four future climate scenarios. Projected habitat loss is greater for species distributed at higher elevations; depending on the climate scenario, we find 36–55% of alpine species, 31–51% of subalpine species and 19–46% of montane species lose more than 80% of their suitable habitat by 2070–2100. While our high‐resolution analyses consistently indicate marked levels of threat to cold‐adapted mountain florae across Europe, they also reveal unequal distribution of this threat across the various mountain ranges. Impacts on florae from regions projected to undergo increased warming accompanied by decreased precipitation, such as the Pyrenees and the Eastern Austrian Alps, will likely be greater than on florae in regions where the increase in temperature is less pronounced and rainfall increases concomitantly, such as in the Norwegian Scandes and the Scottish Highlands. This suggests that change in precipitation, not only warming, plays an important role in determining the potential impacts of climate change on vegetation. 相似文献