scholarly journals Two insulin-responsive glucose transporter isoforms and the insulin receptor are developmentally expressed in rabbit preimplantation embryos

Reproduction ◽  
2004 ◽  
Vol 128 (5) ◽  
pp. 503-516 ◽  
Author(s):  
Anne Navarrete Santos ◽  
Sarah Tonack ◽  
Michaela Kirstein ◽  
Silke Kietz ◽  
Bernd Fischer
Keyword(s):  
Insulin Receptor ◽  
Western Blotting ◽  
Glucose Transporter ◽  
Preimplantation Embryos ◽  
Embryonic Cells ◽  
Coding Region ◽  
Rt Pcr ◽  
Early Embryos ◽  
Perinuclear Cytoplasm ◽  
Race Pcr

Glucose is the most important energy substrate for mammalian blastocysts. Its uptake is mediated by glucose transporters (GLUT). In muscle and adipocyte cells insulin stimulates glucose uptake by activation of the insulin receptor (IR) pathway and translocation of GLUT4. GLUT4 is expressed in bovine preimplantation embryos. A new insulin-responsive isoform, GLUT8, was recently described in mouse blastocysts. Thus, potentially, two insulin-responsive isoforms are expressed in early embryos. The mechanism of insulin action on embryonic cells, however, is still not clear. In the present study expression of IR, GLUT1, 2, 3, 4, 5 and 8 was studied in rabbit preimplantation embryos using RT-PCR, Western blotting and immunohistochemistry. The rabbit mRNA sequences for the complete coding region of IR, GLUT4 and a partial GLUT8 sequence were determined by RACE-PCR and sequencing. GLUT4 was expressed in 3-day-old morulae and in 4- and 6-day-old blastocysts. IR and GLUT8 transcripts were detectable only in blastocysts. Blastocysts also expressed GLUT1 and 3, but not GLUT2 and 5. Transcript numbers of GLUT4 and 8 were higher in trophoblast than in embryoblast cells. Translation of IR, GLUT4 and 8 proteins in blastocysts was confirmed by Western blotting. GLUT4 was localized mainly in the membrane and in the perinuclear region in trophoblast cells while in embryoblast cells its localization was predominantly in the perinuclear cytoplasm. The possible function(s) of two insulin-responsive isoforms, GLUT4 and GLUT8, in rabbit preimplantation embryos needs further investigation. It may not necessarily be linked to insulin-stimulated glucose transport.

scholarly journals Expression of RONIN and NANOG-associated proteins in goat parthenogenetic embryos

2017 ◽  
Vol 11 (2) ◽  
pp. 145 ◽  
Author(s):  
Marcelo Tigre Moura ◽  
Pamela Ramos-Deus ◽  
José Carlos Ferreira-Silva ◽  
Priscila Germany Corrêa Silva ◽  
Ludymila Furtado Cantanhêde ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Expression Patterns ◽  
Preimplantation Embryos ◽  
Rt Pcr ◽  
Cleavage Stage ◽  
Specific Expression ◽  
Early Embryos ◽  
Associated Proteins ◽  
Gene Transcripts

The expression of a subset of transcription factors is enriched in early preimplantation embryos, which contributes to their cellular plasticity. RONIN, NANOG and its associated proteins are PluripotencyAssociated Transcription Factors (PATF) that control relevant downstream pathways in pluripotent stem cells, but their activity in early embryos remained less understood. The work was aimed to determine the expression of RONIN and four NANOG-associated PATFs in goat preimplantation embryos. Goat embryos were produced in vitro by parthenogenetic activation. Gene transcripts of cleavage-stage embryos were investigated by reverse transcriptase-polymerase chain reaction (RT-PCR), while blastocysts were analyzed by both RTPCR and quantitative RT-PCR (RT-qPCR) assays. Gene transcripts of ZFP281, NAC1, and NR0B1 were detected in cleavage-stage embryos, while RONIN and OCT4 were not found expressed. Detection in blastocysts by RT-PCR confirmed the activity of NR0B1, RONIN, and OCT4. Moreover, all five PATF were detected in blastocysts by RT-qPCR (ZFP281, NAC1, RONIN, OCT4, and NR0B1). In conclusion, RONIN and NANOG-associated proteins are active during goat parthenogenetic preimplantation development and hold stage-specific expression patterns.

scholarly journals Adiponectin stimulates glucose uptake in mouse blastocysts and embryonic carcinoma cells

Reproduction ◽  
2020 ◽  
Vol 159 (3) ◽  
pp. 227-239
Author(s):  
J Burkuš ◽  
A Navarrete Santos ◽  
M Schindler ◽  
J Babeľová ◽  
J S Jung ◽  
...  
Keyword(s):  
Glucose Uptake ◽  
P38 Mapk ◽  
Glucose Transporter ◽  
Embryoid Bodies ◽  
Full Length ◽  
Preimplantation Embryos ◽  
Embryonic Cells ◽  
Mapk Phosphorylation ◽  
Embryonic Carcinoma ◽  
Globular Adiponectin

Preimplantation embryos are sensitive to maternal hormones affecting embryonic signal transduction and metabolic functions. We examined whether adiponectin, the most abundantly secreted adipokine, can influence glucose transport in mouse embryonic cells. In mouse blastocysts full-length adiponectin stimulated glucose uptake, while no effect of globular adiponectin was found. Full-length adiponectin stimulated translocation of GLUT8 glucose transporter to the cell membrane; we did not detect significant changes in the intracellular localization of GLUT4 glucose transporter in adiponectin-treated blastocysts. To study adiponectin signaling in detail, we used embryoid bodies formed from mouse embryonic carcinoma cell (ECC) line P19. We confirmed the expression of adiponectin receptors in these cells. Similar to mouse blastocysts, full-length adiponectin, but not globular adiponectin, stimulated glucose uptake in ECC P19 embryoid bodies. Moreover, full-length adiponectin stimulated AMPK and p38 MAPK phosphorylation. These results indicate that besides AMPK, p38 MAPK is a potential target of adiponectin in mouse embryonic cells. AMPK inhibitor did not influence the adiponectin-stimulated p38 MAPK phosphorylation, indicating independent action of these two signaling pathways. In mouse embryos adiponectin acts as a hormonal regulator of glucose uptake, which becomes especially important in phases with reduced levels of circulating insulin. Our results suggest that adiponectin maintains the glucose supply for early embryos under hypoinsulinaemic conditions, for example, in mothers suffering from type 1 diabetes mellitus.

The insulin receptor and the insulin-dependent glucose transporter isoform 4 are expressed in rabbit preimplantation embryos

2002 ◽  
Vol 2002 (Fall) ◽  
Author(s):  
Anne Navarrete Santos ◽  
Sarah Tonack ◽  
Michaela Kirstein ◽  
Bernd Fischer
Keyword(s):  
Insulin Receptor ◽  
Glucose Transporter ◽  
Preimplantation Embryos ◽  
Insulin Dependent

scholarly journals Recycling of the glucose transporter, the insulin receptor, and insulin in rat adipocytes. Effect of acidtropic agents.

1986 ◽  
Vol 261 (7) ◽  
pp. 3295-3305
Author(s):  
O Ezaki ◽  
M Kasuga ◽  
Y Akanuma ◽  
K Takata ◽  
H Hirano ◽  
...  
Keyword(s):  
Insulin Receptor ◽  
Glucose Transporter ◽  
Rat Adipocytes

scholarly journals Involvement of RpoN in Regulating Bacterial Arsenite Oxidation

2012 ◽  
Vol 78 (16) ◽  
pp. 5638-5645 ◽  
Author(s):  
Yoon-Suk Kang ◽  
Brian Bothner ◽  
Christopher Rensing ◽  
Timothy R. McDermott
Keyword(s):  
Binding Site ◽  
Sigma Factor ◽  
Model Organism ◽  
Coding Region ◽  
Rt Pcr ◽  
Obvious Effect ◽  
Content Type ◽  
Definitive Evidence ◽  
Relative Contribution ◽  
Insertional Inactivation

ABSTRACTIn this study with the model organismAgrobacterium tumefaciens, we used a combination oflacZgene fusions, reverse transcriptase PCR (RT-PCR), and deletion and insertional inactivation mutations to show unambiguously that the alternative sigma factor RpoN participates in the regulation of AsIIIoxidation. A deletion mutation that removed the RpoN binding site from theaioBApromoter and anaacC3(gentamicin resistance) cassette insertional inactivation of therpoNcoding region eliminatedaioBAexpression and AsIIIoxidation, althoughrpoNexpression was not related to cell exposure to AsIII. Putative RpoN binding sites were identified throughout the genome and, as examples, included promoters foraioB,phoB1,pstS1,dctA,glnA,glnB, andflgBthat were examined by using qualitative RT-PCR andlacZreporter fusions to assess the relative contribution of RpoN to their transcription. The expressions ofaioBanddctAin the wild-type strain were considerably enhanced in cells exposed to AsIII, and both genes were silent in therpoN::aacC3mutant regardless of AsIII. The expression level ofglnAwas not influenced by AsIIIbut was reduced (but not silent) in therpoN::aacC3mutant and further reduced in the mutant under N starvation conditions. TherpoN::aacC3mutation had no obvious effect on the expression ofglnB,pstS1,phoB1, orflgB. These experiments provide definitive evidence to document the requirement of RpoN for AsIIIoxidation but also illustrate that the presence of a consensus RpoN binding site does not necessarily link the associated gene with regulation by AsIIIor by this sigma factor.

scholarly journals The Progesterone Receptor in Human Term Amniochorion and Placenta Is Isoform C

Endocrinology ◽  
2006 ◽  
Vol 147 (2) ◽  
pp. 687-693 ◽  
Author(s):  
Anthony H. Taylor ◽  
Penny C. McParland ◽  
David J. Taylor ◽  
Stephen C. Bell
Keyword(s):  
Progesterone Receptor ◽  
Western Blotting ◽  
Cell Types ◽  
Specific Role ◽  
Fetal Membranes ◽  
Rt Pcr ◽  
Reproductive Tissues ◽  
Pcr Techniques ◽  
Human Parturition ◽  
Extraembryonic Tissues

The mechanism that initiates human parturition has been proposed to be functional progesterone withdrawal whereby the 116-kDa B isoform of the progesterone receptor (PR-B) switches in favor of the 94-kDa A isoform (PR-A) in reproductive tissues. Recently other PR isoforms, PR-S, PR-C, and PR-M generated from the same gene have been identified and partially characterized. Using immunohistochemical, Western blotting, and RT-PCR techniques, evidence is provided that the major PR isoform present in human term fetal membranes (amnion and chorion) and syncytiotrophoblast of the placenta is neither of the classical nuclear PR-B or PR-A isoforms but is the N terminally truncated 60-kDa PR-C isoform. Evidence is also provided that the PR-C isoform resides in the cytoplasm of the expressing cell types. Data are also presented to show that PR-B, PR-A, and PR-S isoforms are essentially absent from the amnion and chorion, whereas PR isoforms A, B, C, and S are all present in the decidua, with PR-A being the major isoform. The syncytiotrophoblast of the placenta contains the cytoplasmic PR-C isoform but not PR-A, PR-B, or PR-S. The major PR isoform in the amnion, chorion, and placenta is PR-C, suggesting that the cytoplasmic PR-C isoform has a specific role in extraembryonic tissues and may be involved in the regulation of human parturition.

scholarly journals Expression of β-catenin in human trophoblast and its role in placenta accreta and placenta previa

2018 ◽  
Vol 47 (1) ◽  
pp. 206-214
Author(s):  
Qing Han ◽  
Lianghui Zheng ◽  
Zhaodong Liu ◽  
Jinying Luo ◽  
Rongxin Chen ◽  
...  
Keyword(s):  
Western Blotting ◽  
Cell Invasion ◽  
Placenta Accreta ◽  
Placenta Previa ◽  
Control Group ◽  
Rt Pcr ◽  
Lesion Area ◽  
Human Trophoblast ◽  
Chorionic Villi ◽  
Pcr Techniques

Objectives To investigate the expression of β-catenin in chorionic villi, and to explore its roles in placenta accreta and placenta previa. Methods We compared β-catenin expression in the control group, placenta accreta group (lesion area and normal zones), and placenta previa group (placental central and placental edge zones) by immunohistochemistry, Western blotting, and RT-PCR techniques. Results Compared with the normal group, the placenta accreta group had a longer length of stay, greater bleeding volume, and lower newborn birth weight. Further, the expression of β-catenin was lower in both placenta previa and placenta accreta groups than in the control group, as measured by immunohistochemistry. Compared with the control group, expression of β-catenin was significantly lower in the placenta previa and placenta accreta groups by Western blotting and RT-PCR. Importantly, the level of placental β-catenin was significantly different when compared between the lesion and normal zones of placenta. Conclusion The expression of β-catenin in placenta accreta might play an important role in the regulation of placental cell invasion; low expression of β-catenin in placenta accreta might be responsible for excessive trophoblastic invasion.

scholarly journals Insulin-mimetic and insulin-sensitizing activities of a pentacyclic triterpenoid insulin receptor activator

2007 ◽  
Vol 403 (2) ◽  
pp. 243-250 ◽  
Author(s):  
Seung H. Jung ◽  
Yun J. Ha ◽  
Eun K. Shim ◽  
Soo Y. Choi ◽  
Jing L. Jin ◽  
...  
Keyword(s):  
Insulin Receptor ◽  
Tyrosine Phosphorylation ◽  
Glucose Transporter ◽  
Glycogen Synthase ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Β Subunit ◽  
Insulin Sensitizer ◽  
Insulin Mimetic ◽  
Pentacyclic Triterpenoid

Five pentacyclic triterpenoids isolated from Campsis grandiflora were tested for insulin-mimetic and insulin-sensitizing activity. The compounds enhanced the activity of insulin on tyrosine phosphorylation of the IR (insulin receptor) β-subunit in CHO/IR (Chinese-hamster ovary cells expressing human IR). Among the compounds tested, CG7 (ursolic acid) showed the greatest enhancement and CG11 (myrianthic acid) the least. We characterized the effect of CG7 further, and showed that it acted as an effective insulin-mimetic agent at doses above 50 μg/ml and as an insulin-sensitizer at doses as low as 1 μg/ml. Additional experiments showed that CG7 increased the number of IRs that were activated by insulin. This indicates that a major mechanism by which CG7 enhances total IR auto-phosphorylation is by promoting the tyrosine phosphorylation of additional IRs. CG7 not only potentiated insulin-mediated signalling (tyrosine phosphorylation of the IR β-subunit, phosphorylation of Akt and glycogen synthase kinase-3β), but also enhanced the effect of insulin on translocation of glucose transporter 4 in a classical insulin-sensitive cell line, 3T3-L1 adipocytes. The results of the present study demonstrate that a specific pentacyclic triterpenoid, CG7, exerts an insulin-sensitizing effect as an IR activator in CHO/IR cells and adipocytes. The enhancement of insulin activity by CG7 may be useful for developing a new class of specific IR activators for treatment of Type 1 and Type 2 diabetes.

Glucose transporter expression is developmentally regulated in in vitro derived bovine preimplantation embryos

2001 ◽  
Vol 60 (3) ◽  
pp. 370-376 ◽  
Author(s):  
Robert Augustin ◽  
Paola Pocar ◽  
Anne Navarrete-Santos ◽  
Christine Wrenzycki ◽  
Fulvio Gandolfi ◽  
...  
Keyword(s):  
Glucose Transporter ◽  
Preimplantation Embryos ◽  
Developmentally Regulated ◽  
Transporter Expression
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