排序方式: 共有187条查询结果,搜索用时 359 毫秒
61.
Macarena Rojas Pablo Díaz Pablo León Alexis A. Gonzalez Magdalena González Víctor Barrientos 《Channels (Austin, Tex.)》2017,11(5):388-398
Renal sodium reabsorption depends on the activity of the Na+,K+-ATPase α/β heterodimer. Four α (α1–4) and 3 β (β1–3) subunit isoforms have been described. It is accepted that renal tubule cells express α1/β1 dimers. Aldosterone stimulates Na+,K+-ATPase activity and may modulate α1/β1 expression. However, some studies suggest the presence of β3 in the kidney. We hypothesized that the β3 isoform of the Na+,K+-ATPase is expressed in tubular cells of the distal nephron, and modulated by mineralocorticoids. We found that β3 is highly expressed in collecting duct of rodents, and that mineralocorticoids decreased the expression of β3. Thus, we describe a novel molecular mechanism of sodium pump modulation that may contribute to the effects of mineralocorticoids on sodium reabsorption. 相似文献
62.
Cristina Fuster Monica Varese Jesús García Ernest Giralt Macarena Snchez‐Navarro Meritxell Teixid 《Journal of peptide science》2019,25(5)
Venoms have recently emerged as a promising field in drug discovery due to their good selectivity and affinity for a wide range of biological targets. Among their multiple potential applications, venoms are a rich source of blood‐brain barrier (BBB) peptide shuttles. We previously described a short nontoxic derivative of apamin, MiniAp‐4, which can transport a wide range of cargoes across the BBB. Here, we have studied the conformation of the proline residue of a range of MiniAp‐4 analogues by high‐field NMR techniques, with the aim to identify whether there is a direct relation between the cis/trans population and a range of features, such as the capacity to transport molecules across a human‐based cellular model and stability in various media. The most promising candidate showed improved transport properties for a relevant small fluorophore. 相似文献
63.
Michelle Re Macarena Pampillo Martin Savard Céléna Dubuc Craig A. McArdle Robert P. Millar P. Michael Conn Fernand Gobeil Jr Moshmi Bhattacharya Andy V. Babwah 《PloS one》2010,5(7)
The mammalian type I gonadotropin releasing hormone receptor (GnRH-R) is a structurally unique G protein-coupled receptor (GPCR) that lacks cytoplasmic tail sequences and displays inefficient plasma membrane expression (PME). Compared to its murine counterparts, the primate type I receptor is inefficiently folded and retained in the endoplasmic reticulum (ER) leading to a further reduction in PME. The decrease in PME and concomitant increase in intracellular localization of the mammalian GnRH-RI led us to characterize the spatial distribution of the human and mouse GnRH receptors in two human cell lines, HEK 293 and HTR-8/SVneo. In both human cell lines we found the receptors were expressed in the cytoplasm and were associated with the ER and nuclear membrane. A molecular analysis of the receptor protein sequence led us to identify a putative monopartite nuclear localization sequence (NLS) in the first intracellular loop of GnRH-RI. Surprisingly, however, neither the deletion of the NLS nor the addition of the Xenopus GnRH-R cytoplasmic tail sequences to the human receptor altered its spatial distribution. Finally, we demonstrate that GnRH treatment of nuclei isolated from HEK 293 cells expressing exogenous GnRH-RI triggers a significant increase in the acetylation and phosphorylation of histone H3, thereby revealing that the nuclear-localized receptor is functional. Based on our findings, we conclude that the mammalian GnRH-RI is an intracellular GPCR that is expressed on the nuclear membrane. This major and novel discovery causes us to reassess the signaling potential of this physiologically and clinically important receptor. 相似文献
64.
Cristian A. Acevedo Rodrigo A. Somoza Caroline Weinstein-Oppenheimer Samy Silva Macarena Moreno Elizabeth Sánchez Fernando Albornoz Manuel E. Young William MacNaughtan Javier Enrione 《Bioprocess and biosystems engineering》2013,36(3):317-324
Gelatin-/chitosan-/hyaluronan-based biomaterials are used in tissue engineering as cell scaffolds. Three gamma radiation doses (1, 10 and 25 kGy) were applied to scaffolds for sterilization. Microstructural changes of the irradiated polymers were evaluated by using scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). A dose of 25 kGy produced a rough microstructure with a reduction of the porosity (from 99 to 96 %) and pore size (from 160 to 123 μm). Radiation also modified the glass transition temperature between 31.2 and 42.1 °C (1 and 25 kGy respectively). Human skin cells cultivated on scaffolds irradiated with 10 and 25 kGy proliferated at 48 h and secreted transforming growth factor β3 (TGF-β3). Doses of 0 kGy (non-irradiated) or 1 kGy did not stimulate TGF-β3 secretion or cell proliferation. The specific growth rate and lactate production increased proportionally to radiation dose. The use of an appropriate radiation dose improves the cell scaffold properties of biomaterials. 相似文献
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66.
Macarena Peran Sergio Ruiz Witek Kwiatkowski Juan Antonio Marchal Sheng-Lian Yang Antonia Aranega Senyon Choe Juan Carlos Izpisua Belmonte 《Stem cell research》2013,10(3):464-476
Human adipose derived stem cells (hASCs) can be easily isolated and their plasticity has been well characterized. Several TGF-β superfamily ligands can direct hASCs towards chondrocytes. However, these ligands are difficult to purify and expensive. We have developed a library of Activin/BMP2 chimeric ligands (AB2 ligands) by systematically mixing their sequence segments and have tested their chondrogenic potential in hASCs. Cells cultured in monolayer or in a pellet culture system were incubated with a chemically defined medium supplemented with the chimeric ligands for 4 or 6 weeks and showed higher expression levels of type II collagen, aggrecan, and Sox9 mRNAs when compared with control and non-treated cells. Moreover, toluidine blue, alcian blue, and Masson's trichrome staining was markedly increased in treated cells, both in cell pellet and monolayer assays. In addition, immunohistochemical staining for detection of type I collagen, type II collagen, and Sox 9 demonstrated the acquisition of a chondrogenic phenotype in both culture systems. We present here an inexpensive and robust protocol for differentiation of hASCs towards chondrocytes in a reproducible and highly efficient manner. The AB2 ligands employed are easily produced and have properties that may become useful in cell therapy. 相似文献
67.
Riquelme G Vallejos C de Gregorio N Morales B Godoy V Berrios M Bastías N Rodríguez C 《The Journal of membrane biology》2011,241(3):127-140
Intrauterine growth restriction (IUGR) and preeclampsia (PE) are leading causes of perinatal and maternal morbidity and mortality.
Previously we reported the expression of lipid rafts in classical microvillous membrane (MVM) and light microvillous membrane
(LMVM), two subdomains in apical membrane from the human placental syncytiotrophoblast (hSTB), which constitute the epithelium
responsible for maternal–fetal transport. Here the aim was to study the raft and cytoskeletal proteins from PE and IUGR. Microdomains
from MVM and LMVM were tested with raft markers (placental alkaline phosphatase, lipid ganglioside, and annexin 2) and a nonraft
marker (hTf-R). No changes were detected with those markers in whole purified apical membranes in normal, PE, and IUGR pregnancies;
however, their patterns of distribution in lipid rafts were different in PE and IUGR. Cholesterol depletion modified their
segregation, confirming their presence in lipid rafts, although unlike normal placenta, in these pathologies there is only
one type of microdomain. Additionally, the cytoskeleton proteins actin, ezrin, and cytokeratin-7 showed clear differences
between normal and pathological membranes. Cytokeratin-7 expression decreased to 50% in PE, and the distribution between LMVM
and MVM (~43 and 57%, respectively) changed in both PE and IUGR, in contrast with the asymmetrical enrichment obtained in
normal LMVM (~62%). In conclusion, lipid rafts from IUGR and PE have different features compared to rafts from normal placentae,
and this is associated with alterations in the expression and distribution of cytoskeletal proteins. 相似文献
68.
Amiano N Reiteri RM Costa MJ Tateosian N Chuluyan HE 《Cancer immunology, immunotherapy : CII》2011,60(6):895-900
We have demonstrated previously that the inoculation of murine mammary tumor cells genetically modified to express high levels
of secretory leukocyte protease inhibitor (2C1) do not develop tumors in immunocompetent mice and these cells are more prone
to apoptosis than control cells. The aim of the present study was to evaluate the role of the adaptive immune response in
the lack of tumor growth of 2C1 cells and the possibility of using these cells for immunotherapy. The s.c. administration
of mock transfected F3II cells induces tumor in BALB/c and Nude mice. However, the inoculation of 2C1 cells develops tumor
in Nude but not in BALB/c mice. The inoculation of mock transfected F3II cells to 2C1 immunized BALB/c mice by repeated administration
of 2C1 cells (once a week for 3 weeks) developed significantly smaller tumors than those observed in non-immunized mice. Remarkably,
survival of tumor-bearing immunized mice was higher than non-immunized animals. Herein, we demonstrate that an immunotherapy
with SLPI over-expressing non-irradiated tumor cells which do not develop tumor in immunocompetent mice, partially restrain
the tumor growth induced by F3II cells and increase the survival of the mice. 相似文献
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Michel Guipponi Federico A. Santoni Vincent Setola Corinne Gehrig Maud Rotharmel Macarena Cuenca Olivier Guillin Dimitris Dikeos Georgios Georgantopoulos George Papadimitriou Logos Curtis Alexandre Méary Franck Schürhoff Stéphane Jamain Dimitri Avramopoulos Marion Leboyer Dan Rujescu Ann Pulver Dominique Campion David P. Siderovski Stylianos E. Antonarakis 《PloS one》2014,9(11)
Schizophrenia (SCZ) is a severe, debilitating mental illness which has a significant genetic component. The identification of genetic factors related to SCZ has been challenging and these factors remain largely unknown. To evaluate the contribution of de novo variants (DNVs) to SCZ, we sequenced the exomes of 53 individuals with sporadic SCZ and of their non-affected parents. We identified 49 DNVs, 18 of which were predicted to alter gene function, including 13 damaging missense mutations, 2 conserved splice site mutations, 2 nonsense mutations, and 1 frameshift deletion. The average number of exonic DNV per proband was 0.88, which corresponds to an exonic point mutation rate of 1.7×10−8 per nucleotide per generation. The non-synonymous-to-synonymous mutation ratio of 2.06 did not differ from neutral expectations. Overall, this study provides a list of 18 putative candidate genes for sporadic SCZ, and when combined with the results of similar reports, identifies a second proband carrying a non-synonymous DNV in the RGS12 gene. 相似文献