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Jacques Baudier - One of the best experts on this subject based on the ideXlab platform.
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nuclear expression of s100b in oligodendrocyte progenitor cells correlates with differentiation toward the oligodendroglial lineage and modulates oligodendrocytes maturation
Molecular and Cellular Neuroscience, 2004Co-Authors: Jeanchristophe Deloulme, Alexander Marks, Benoit J Gentil, Eric Raponi, Nathalie Bertacchi, G Labourdette, Jacques BaudierAbstract:The S100B protein belongs to the S100 family of EF-hand calcium binding proteins implicated in cell growth and differentiation. Here, we show that in the developing and the adult mouse brain, S100B is expressed in oligodendroglial progenitor cells (OPC) committed to differentiate into the oligodendrocyte (OL) lineage. Nuclear S100B accumulation in OPC correlates with the transition from the fast dividing multipotent stage to the morphological differentiated, slow proliferating, pro-OL differentiation stage. In the adult, S100B expression is down-regulated in mature OLs that have established contacts with their axonal targets, suggesting a nuclear S100B function during oligodendroglial cells maturation. In vitro, the morphological transformation and maturation of pro-OL cells are delayed in the absence of S100B. Moreover, mice lacking S100B show an apparent delay in OPC maturation in response to demyelinating insult. We propose that nuclear S100B participates in the regulation of oligodendroglial cell maturation.
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the giant protein ahnak is a specific target for the calcium and zinc binding s100b protein potential implications for ca2 homeostasis regulation by s100b
Journal of Biological Chemistry, 2001Co-Authors: Benoit J Gentil, Jeanchristophe Deloulme, Gaelh Ouengue Mbele, Christian Delphin, Myriam Ferro, Jerome Garin, Jacques BaudierAbstract:Abstract Transformation of rat embryo fibroblast clone 6 cells by ras and temperature-sensitive p53val135 is reverted by ectopic expression of the calcium- and zinc-binding protein S100B. In an attempt to define the molecular basis of the S100B action, we have identified the giant phosphoprotein AHNAK as the major and most specific Ca2+-dependent S100B target protein in rat embryo fibroblast cells. We next characterized AHNAK as a major Ca2+-dependent S100B target protein in the rat glial C6 and human U-87MG astrocytoma cell lines. AHNAK binds to S100B-Sepharose beads and is also recovered in anti-S100B immunoprecipitates in a strict Ca2+- and Zn2+-dependent manner. Using truncated AHNAK fragments, we demonstrated that the domains of AHNAK responsible for interaction with S100B correspond to repeated motifs that characterize the AHNAK molecule. These motifs show no binding to calmodulin or to S100A6 and S100A11. We also provide evidence that the binding of 2 Zn2+ equivalents/mol S100B enhances Ca2+-dependent S100B-AHNAK interaction and that the effect of Zn2+ relies on Zn2+-dependent regulation of S100B affinity for Ca2+. Taking into consideration that AHNAK is a protein implicated in calcium flux regulation, we propose that the S100B-AHNAK interaction may participate in the S100B-mediated regulation of cellular Ca2+ homeostasis.
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s100a6 and s100a11 are specific targets of the calcium and zinc binding s100b protein in vivo
Journal of Biological Chemistry, 2000Co-Authors: Jeanchristophe Deloulme, Nicole Assard, Gaelh Ouengue Mbele, Carole Mangin, Ryozo Kuwano, Jacques BaudierAbstract:In solution, S100B protein is a noncovalent homodimer composed of two subunits associated in an antiparallel manner. Upon calcium binding, the conformation of S100B changes dramatically, leading to the exposure of hydrophobic residues at the surface of S100B. The residues in the C-terminal domain of S100B encompassing Phe87 and Phe88 have been implicated in interaction with target proteins. In this study, we used two-hybrid technology to identify specific S100B target proteins. Using S100B as bait, we identify S100A6 and S100A11 as specific targets for S100B. S100A1, the closest homologue of S100B, is capable of interaction with S100B but does not interact with S100A6 or S100A11. S100B, S100A6, and S100A11 isoforms are co-regulated and co-localized in astrocytoma U373 cells. Furthermore, co-immunoprecipitation experiments demonstrated that Ca2+/Zn2+stabilizes S100B-S100A6 and S100B-S100A11 heterocomplexes. Deletion of the C-terminal domain or mutation of Phe87 and Phe88 residues has no effect on S100B homodimerization and heterodimerization with S100A1 but drastically decreases interaction between S100B and S100A6 or S100A11. Our data suggest that the interaction between S100B and S100A6 or S100A11 should not be viewed as a typical S100 heterodimerization but rather as a model of interaction between S100B and target proteins.
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cysteine oxidation in the mitogenic s100b protein leads to changes in phosphorylation by catalytic ckii α subunit
Journal of Biological Chemistry, 1998Co-Authors: Christian Scotto, Jerome Garin, Yves Mely, Hiroshi Ohshima, Claude Cochet, E M Chambaz, Jacques BaudierAbstract:Abstract The glial-derived calcium-binding protein S100B can be secreted to act as a neurotrophic factor or a mitogen, stimulating proliferation of glial cells. The extracellular S100B activities rely on the oxidation of the protein cysteine residues (Kligman, D., and Marshak, D. R. (1985) Proc. Natl. Acad. Sci. U. S. A. 82, 7136–7139; Winningham-Major, F., Staecker, J. L., Barger, S. W., Coats, S., and Van Eldik, L. J. (1989) J. Cell Biol. 109, 3063–3071). Here we show that oxidation of the S100B cysteine residues, Cys-68 and Cys-84, induces a conformational change in the protein structure, unmasking a canonical CKII phosphorylation site located within the typical EF-hand calcium-binding site IIβ. Intrasubunit disulfide-bridged S100B monomer and disulfide-bonded S100B dimer are phosphorylated by the catalytic CKII-α subunit on Ser-62 with a K m of 0.5 μm and a V max of 10 pmol/min/100 pmol of S100B. Oxidized S100B is the best in vitro CKII-α substrate identified so far. Next we show that intrasubunit disulfide-bridged S100B monomer is the most potent S100B species to stimulate [3H]thymidine uptake by C6 glial cells in culture. In addition, the phosphorylated intrasubunit disulfide-bridged S100B monomer retains apparent mitogenic activity toward C6 glial cells, and hence, 32P-labeled S100B should be a useful probe for characterizing the mechanisms by which extracellular oxidized S100B functions. Finally, we show that formation of intrasubunit disulfide-bridged S100B monomer is stimulated by peroxynitrite anion, suggesting that production of mitogenic S100B species could be enhanced in neuropathology associated with peroxynitrite anion production.
David J. Weber - One of the best experts on this subject based on the ideXlab platform.
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the calcium dependent interaction of s100b with its protein targets
Cardiovascular Psychiatry and Neurology, 2010Co-Authors: Danna B Zimmer, David J. WeberAbstract:S100B is a calcium signaling protein that is a member of the S100 protein family. An important feature of S100B and most other S100 proteins (S100s) is that they often bind Ca(2+) ions relatively weakly in the absence of a protein target; upon binding their target proteins, Ca(2+)-binding then increases by as much as from 200- to 400-fold. This manuscript reviews the structural basis and physiological significance of increased Ca(2+)-binding affinity in the presence of protein targets. New information regarding redundancy among family members and the structural domains that mediate the interaction of S100B, and other S100s, with their targets is also presented. It is the diversity among individual S100s, the protein targets that they interact with, and the Ca(2+) dependency of these protein-protein interactions that allow S100s to transduce changes in [Ca(2+)](intracellular) levels into spatially and temporally unique biological responses.
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The calcium-binding protein S100B down-regulates p53 and apoptosis in malignant melanoma.
The Journal of biological chemistry, 2010Co-Authors: Jing Lin, Paul T. Wilder, Qingyuan Yang, David J. WeberAbstract:The S100B-p53 protein complex was discovered in C8146A malignant melanoma, but the consequences of this interaction required further study. When S100B expression was inhibited in C8146As by siRNA (siRNA(S100B)), wt p53 mRNA levels were unchanged, but p53 protein, phosphorylated p53, and p53 gene products (i.e. p21 and PIDD) were increased. siRNA(S100B) transfections also restored p53-dependent apoptosis in C8146As as judged by poly(ADP-ribose) polymerase cleavage, DNA ladder formation, caspase 3 and 8 activation, and aggregation of the Fas death receptor (+UV); whereas, siRNA(S100B) had no effect in SK-MEL-28 cells containing elevated S100B and inactive p53 (p53R145L mutant). siRNA(S100B)-mediated apoptosis was independent of the mitochondria, because no changes were observed in mitochondrial membrane potential, cytochrome c release, caspase 9 activation, or ratios of pro- and anti-apoptotic proteins (BAX, Bcl-2, and Bcl-X(L)). As expected, cells lacking S100B (LOX-IM VI) were not affected by siRNA(S100B), and introduction of S100B reduced their UV-induced apoptosis activity by 7-fold, further demonstrating that S100B inhibits apoptosis activities in p53-containing cells. In other wild-type p53 cells (i.e. C8146A, UACC-2571, and UACC-62), S100B was found to contribute to cell survival after UV treatment, and for C8146As, the decrease in survival after siRNA(S100B) transfection (+UV) could be reversed by the p53 inhibitor, pifithrin-alpha. In summary, reducing S100B expression with siRNA was sufficient to activate p53, its transcriptional activation activities, and p53-dependent apoptosis pathway(s) in melanoma involving the Fas death receptor and perhaps PIDD. Thus, a well known marker for malignant melanoma, S100B, likely contributes to cancer progression by down-regulating the tumor suppressor protein, p53.
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the effects of capz peptide trtk 12 binding to s100b ca2 as examined by nmr and x ray crystallography
Journal of Molecular Biology, 2010Co-Authors: Thomas H Charpentier, Paul T. Wilder, Eric A. Toth, Laura E Thompson, Melissa A Liriano, Kristen M Varney, Edwin Pozharski, David J. WeberAbstract:Structure-based drug design is underway to inhibit the S100B-p53 interaction as a strategy for treating malignant melanoma. X-ray crystallography was used here to characterize an interaction between Ca(2)(+)-S100B and TRTK-12, a target that binds to the p53-binding site on S100B. The structures of Ca(2+)-S100B (1.5-A resolution) and S100B-Ca(2)(+)-TRTK-12 (2.0-A resolution) determined here indicate that the S100B-Ca(2+)-TRTK-12 complex is dominated by an interaction between Trp7 of TRTK-12 and a hydrophobic binding pocket exposed on Ca(2+)-S100B involving residues in helices 2 and 3 and loop 2. As with an S100B-Ca(2)(+)-p53 peptide complex, TRTK-12 binding to Ca(2+)-S100B was found to increase the protein's Ca(2)(+)-binding affinity. One explanation for this effect was that peptide binding introduced a structural change that increased the number of Ca(2+) ligands and/or improved the Ca(2+) coordination geometry of S100B. This possibility was ruled out when the structures of S100B-Ca(2+)-TRTK-12 and S100B-Ca(2+) were compared and calcium ion coordination by the protein was found to be nearly identical in both EF-hand calcium-binding domains (RMSD=0.19). On the other hand, B-factors for residues in EF2 of Ca(2+)-S100B were found to be significantly lowered with TRTK-12 bound. This result is consistent with NMR (15)N relaxation studies that showed that TRTK-12 binding eliminated dynamic properties observed in Ca(2+)-S100B. Such a loss of protein motion may also provide an explanation for how calcium-ion-binding affinity is increased upon binding a target. Lastly, it follows that any small-molecule inhibitor bound to Ca(2+)-S100B would also have to cause an increase in calcium-ion-binding affinity to be effective therapeutically inside a cell, so these data need to be considered in future drug design studies involving S100B.
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divalent metal ion complexes of s100b in the absence and presence of pentamidine
Journal of Molecular Biology, 2008Co-Authors: Thomas H Charpentier, Paul T. Wilder, Andrew Coop, Alexander D. Mackerell, Eric A. Toth, Melissa A Liriano, Kristen M Varney, Edwin Pozharski, David J. WeberAbstract:As part of an effort to inhibit S100B, structures of pentamidine (Pnt) bound to Ca{sup 2+}-loaded and Zn{sup 2+},Ca{sup 2+}-loaded S100B were determined by X-ray crystallography at 2.15 {angstrom} (R{sub free} = 0.266) and 1.85 {angstrom} (R{sub free} = 0.243) resolution, respectively. These data were compared to X-ray structures solved in the absence of Pnt, including Ca{sup 2+}-loaded S100B and Zn{sup 2+},Ca{sup 2+}-loaded S100B determined here (1.88 {angstrom}; R{sub free} = 0.267). In the presence and absence of Zn{sup 2+}, electron density corresponding to two Pnt molecules per S100B subunit was mapped for both drug-bound structures. One Pnt binding site (site 1) was adjacent to a p53 peptide binding site on S100B ({+-} Zn{sup 2+}), and the second Pnt molecule was mapped to the dimer interface (site 2; {+-} Zn{sup 2+}) and in a pocket near residues that define the Zn{sup 2+} binding site on S100B. In addition, a conformational change in S100B was observed upon the addition of Zn{sup 2+} to Ca{sup 2+}-S100B, which changed the conformation and orientation of Pnt bound to sites 1 and 2 of Pnt-Zn{sup 2+},Ca{sup 2+}-S100B when compared to Pnt-Ca{sup 2+}-S100B. That Pnt can adapt to this Zn{sup 2+}-dependent conformational change was unexpected andmore » provides a new mode for S100B inhibition by this drug. These data will be useful for developing novel inhibitors of both Ca{sup 2+}- and Ca{sup 2+},Zn{sup 2+}-bound S100B.« less
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Solution NMR structure of S100B bound to the high-affinity target peptide TRTK-12
Journal of molecular biology, 2002Co-Authors: Keith G. Inman, Richard R. Rustandi, Ruiqing Yang, Kristine E. Miller, Donna M. Baldisseri, David J. WeberAbstract:Abstract The solution NMR structure is reported for Ca2+-loaded S100B bound to a 12-residue peptide, TRTK-12, from the actin capping protein CapZ (α1 or α2 subunit, residues 265–276: TRTKIDWNKILS). This peptide was discovered by Dimlich and co-workers by screening a bacteriophage random peptide display library, and it matches exactly the consensus S100B binding sequence ((K/R)(L/I)XWXXIL). As with other S100B target proteins, a calcium-dependent conformational change in S100B is required for TRTK-12 binding. The TRTK-12 peptide is an amphipathic helix (residues W7 to S12) in the S100B–TRTK complex, and helix 4 of S100B is extended by three or four residues upon peptide binding. However, helical TRTK-12 in the S100B–peptide complex is uniquely oriented when compared to the three-dimensional structures of other S100–peptide complexes. The three-dimensional structure of the S100B–TRTK peptide complex illustrates that residues in the S100B binding consensus sequence (K4, I5, W7, I10, L11) are all involved in the S100B–peptide interface, which can explain its orientation in the S100B binding pocket and its relatively high binding affinity. A comparison of the S100B–TRTK peptide structure to the structures of apo- and Ca2+-bound S100B illustrates that the binding site of TRTK-12 is buried in apo-S100B, but is exposed in Ca2+-bound S100B as necessary to bind the TRTK-12 peptide.
Yohan Choi - One of the best experts on this subject based on the ideXlab platform.
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Regulation of S100G Expression in the Uterine Endometrium during Early Pregnancy in Pigs.
Asian-Australasian journal of animal sciences, 2011Co-Authors: Yohan Choi, Heewon Seo, Jangsoo Shim, Mingoo KimAbstract:Calcium ions play an important role in the establishment and maintenance of pregnancy, but molecular and cellular regulatory mechanisms of calcium ion action in the uterine endometrium are not fully understood in pigs. Previously, we have shown that calcium regulatory molecules, transient receptor potential vanilloid type 5 (TRPV6) and calbindin-D9k (S100G), are expressed in the uterine endometrium during the estrous cycle and pregnancy in a pregnancy status- and stage-specific manner, and that estrogen of conceptus origin increases endometrial TRPV6 expression. However, regulation of S100G expression in the uterine endometrium and conceptus expression of S100G has been not determined during early pregnancy. Thus, we investigated regulation of S100G expression by estrogen and interleukin-1β (IL1B) in the uterine endometrium and conceptus expression of S100G during early pregnancy in pigs. We obtained uterine endometrial tissues from day (D) 12 of the estrous cycle and treated with combinations of steroid hormones, estradiol-17β (E2) and progesterone (P4), and increasing doses of IL1B. Real-time RT-PCR analysis showed that E2 and IL1B increased S100G mRNA levels in the uterine endometrium, and conceptuses expressed S100G mRNA during early pregnancy, as determined by RT-PCR analysis. To determine if endometrial expression of S100G mRNA during the implantation period was affected by the somatic cell nuclear transfer (SCNT) procedure, we compared S100G mRNA levels in the uterine endometrium from gilts with SCNT-derived conceptuses with those from gilts with conceptuses derived from natural mating on D12 of pregnancy. Real-time RT-PCR analysis showed that levels of S100G mRNA in the uterine endometrium from gilts carrying SCNT-derived conceptuses was significantly lower than those from gilts carrying conceptuses derived from natural mating. These results showed that S100G expression in the uterine endometrium was regulated by estrogen and IL1B of conceptus origin, and affected by the SCNT procedure during early pregnancy. These suggest that conceptus signals regulate S100G, an intracellular calcium transport protein, for the establishment of pregnancy in pigs.
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dynamic expression of calcium regulatory molecules trpv6 and S100G in the uterine endometrium during pregnancy in pigs
Biology of Reproduction, 2009Co-Authors: Yohan Choi, Hakhyun KaAbstract:Calcium ions have been implicated in the establishment and maintenance of pregnancy, but the regulatory mechanisms of calcium ions in the uterine endometrium and conceptus are not well understood in pigs. Recently, we showed that TRPV6, a calcium ion channel protein associated with cellular entry of calcium ions, is highly expressed in the uterine endometrium during the implantation period in pigs. In the present study, we investigated spatial and temporal expression and regulation of TRPV6 and S100G, an intracellular calcium-regulatory molecule, in the uterine endometrium during the estrous cycle and pregnancy in pigs. TRPV6 expression was maintained at significantly higher levels in the uterine endometrium during pregnancy compared with levels during the estrous cycle. TRPV6 transcripts and proteins were localized mainly to luminal epithelial cells (LE) and weakly to glandular epithelial cells (GE) and chorionic membrane (CM) during pregnancy. TRPV6 expression was also detected in conceptuses on Day (D) 12 and D15. TRPV6 mRNA levels in the endometrium were increased by estrogen treatment. S100G expression showed a biphasic pattern of increases on D12 of pregnancy and from D60 to term pregnancy, and it localized primarily to LE during early pregnancy and to LE, GE, and CM from D30 to term pregnancy. These results indicate that spatial and temporal expression of TRPV6 and S100G is dynamically regulated in the uterine endometrium during pregnancy and that endometrial regulation of calcium ion concentration by TRPV6 and S100G may be critical for the establishment and maintenance of pregnancy in pigs.
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Dynamic expression of calcium-regulatory molecules, TRPV6 and S100G, in the uterine endometrium during pregnancy in pigs.
Biology of reproduction, 2009Co-Authors: Yohan Choi, Heewon Seo, Mingoo KimAbstract:Calcium ions have been implicated in the establishment and maintenance of pregnancy, but the regulatory mechanisms of calcium ions in the uterine endometrium and conceptus are not well understood in pigs. Recently, we showed that TRPV6, a calcium ion channel protein associated with cellular entry of calcium ions, is highly expressed in the uterine endometrium during the implantation period in pigs. In the present study, we investigated spatial and temporal expression and regulation of TRPV6 and S100G, an intracellular calcium-regulatory molecule, in the uterine endometrium during the estrous cycle and pregnancy in pigs. TRPV6 expression was maintained at significantly higher levels in the uterine endometrium during pregnancy compared with levels during the estrous cycle. TRPV6 transcripts and proteins were localized mainly to luminal epithelial cells (LE) and weakly to glandular epithelial cells (GE) and chorionic membrane (CM) during pregnancy. TRPV6 expression was also detected in conceptuses on Day (D) 12 and D15. TRPV6 mRNA levels in the endometrium were increased by estrogen treatment. S100G expression showed a biphasic pattern of increases on D12 of pregnancy and from D60 to term pregnancy, and it localized primarily to LE during early pregnancy and to LE, GE, and CM from D30 to term pregnancy. These results indicate that spatial and temporal expression of TRPV6 and S100G is dynamically regulated in the uterine endometrium during pregnancy and that endometrial regulation of calcium ion concentration by TRPV6 and S100G may be critical for the establishment and maintenance of pregnancy in pigs.
Mingoo Kim - One of the best experts on this subject based on the ideXlab platform.
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Regulation of S100G Expression in the Uterine Endometrium during Early Pregnancy in Pigs.
Asian-Australasian journal of animal sciences, 2011Co-Authors: Yohan Choi, Heewon Seo, Jangsoo Shim, Mingoo KimAbstract:Calcium ions play an important role in the establishment and maintenance of pregnancy, but molecular and cellular regulatory mechanisms of calcium ion action in the uterine endometrium are not fully understood in pigs. Previously, we have shown that calcium regulatory molecules, transient receptor potential vanilloid type 5 (TRPV6) and calbindin-D9k (S100G), are expressed in the uterine endometrium during the estrous cycle and pregnancy in a pregnancy status- and stage-specific manner, and that estrogen of conceptus origin increases endometrial TRPV6 expression. However, regulation of S100G expression in the uterine endometrium and conceptus expression of S100G has been not determined during early pregnancy. Thus, we investigated regulation of S100G expression by estrogen and interleukin-1β (IL1B) in the uterine endometrium and conceptus expression of S100G during early pregnancy in pigs. We obtained uterine endometrial tissues from day (D) 12 of the estrous cycle and treated with combinations of steroid hormones, estradiol-17β (E2) and progesterone (P4), and increasing doses of IL1B. Real-time RT-PCR analysis showed that E2 and IL1B increased S100G mRNA levels in the uterine endometrium, and conceptuses expressed S100G mRNA during early pregnancy, as determined by RT-PCR analysis. To determine if endometrial expression of S100G mRNA during the implantation period was affected by the somatic cell nuclear transfer (SCNT) procedure, we compared S100G mRNA levels in the uterine endometrium from gilts with SCNT-derived conceptuses with those from gilts with conceptuses derived from natural mating on D12 of pregnancy. Real-time RT-PCR analysis showed that levels of S100G mRNA in the uterine endometrium from gilts carrying SCNT-derived conceptuses was significantly lower than those from gilts carrying conceptuses derived from natural mating. These results showed that S100G expression in the uterine endometrium was regulated by estrogen and IL1B of conceptus origin, and affected by the SCNT procedure during early pregnancy. These suggest that conceptus signals regulate S100G, an intracellular calcium transport protein, for the establishment of pregnancy in pigs.
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Dynamic expression of calcium-regulatory molecules, TRPV6 and S100G, in the uterine endometrium during pregnancy in pigs.
Biology of reproduction, 2009Co-Authors: Yohan Choi, Heewon Seo, Mingoo KimAbstract:Calcium ions have been implicated in the establishment and maintenance of pregnancy, but the regulatory mechanisms of calcium ions in the uterine endometrium and conceptus are not well understood in pigs. Recently, we showed that TRPV6, a calcium ion channel protein associated with cellular entry of calcium ions, is highly expressed in the uterine endometrium during the implantation period in pigs. In the present study, we investigated spatial and temporal expression and regulation of TRPV6 and S100G, an intracellular calcium-regulatory molecule, in the uterine endometrium during the estrous cycle and pregnancy in pigs. TRPV6 expression was maintained at significantly higher levels in the uterine endometrium during pregnancy compared with levels during the estrous cycle. TRPV6 transcripts and proteins were localized mainly to luminal epithelial cells (LE) and weakly to glandular epithelial cells (GE) and chorionic membrane (CM) during pregnancy. TRPV6 expression was also detected in conceptuses on Day (D) 12 and D15. TRPV6 mRNA levels in the endometrium were increased by estrogen treatment. S100G expression showed a biphasic pattern of increases on D12 of pregnancy and from D60 to term pregnancy, and it localized primarily to LE during early pregnancy and to LE, GE, and CM from D30 to term pregnancy. These results indicate that spatial and temporal expression of TRPV6 and S100G is dynamically regulated in the uterine endometrium during pregnancy and that endometrial regulation of calcium ion concentration by TRPV6 and S100G may be critical for the establishment and maintenance of pregnancy in pigs.
Mark A. Nelson - One of the best experts on this subject based on the ideXlab platform.
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the s100p rage signaling pathway regulates expression of microrna 21 in colon cancer cells
FEBS Letters, 2015Co-Authors: Melania E Mercadopimentel, Benjamin C. Onyeagucha, Angel C. Pimentel, Jana Jandova, Mark A. NelsonAbstract:S100P signaling through the receptor for advanced glycation end-products (RAGE) contributes to colon cancer invasion and metastasis, but the mechanistic features of this process are obscure. Here, we investigate whether activation of S100P/RAGE signaling regulates oncogenic microRNA-21 (miR-21). We show that exogenous S100P up-regulates miR-21 levels in human colon cancer cells, whereas knockdown of S100P results in a decrease of miR-21. Furthermore, blockage of RAGE with anti-RAGE antibody suppresses S100P induction of miR-21. In addition, we found that S100P induction of miR-21 expression involves ERK and is suppressed by the MEK inhibitor U0126. Also, S100P treatment stimulates the enrichment of c-Fos, and AP-1 family members, at the miR-21 gene promoter.
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The S100P/RAGE signaling pathway regulates expression of microRNA-21 in colon cancer cells.
FEBS letters, 2015Co-Authors: Melania E. Mercado-pimentel, Benjamin C. Onyeagucha, Angel C. Pimentel, Jana Jandova, Mark A. NelsonAbstract:S100P signaling through the receptor for advanced glycation end-products (RAGE) contributes to colon cancer invasion and metastasis, but the mechanistic features of this process are obscure. Here, we investigate whether activation of S100P/RAGE signaling regulates oncogenic microRNA-21 (miR-21). We show that exogenous S100P up-regulates miR-21 levels in human colon cancer cells, whereas knockdown of S100P results in a decrease of miR-21. Furthermore, blockage of RAGE with anti-RAGE antibody suppresses S100P induction of miR-21. In addition, we found that S100P induction of miR-21 expression involves ERK and is suppressed by the MEK inhibitor U0126. Also, S100P treatment stimulates the enrichment of c-Fos, and AP-1 family members, at the miR-21 gene promoter.
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s100p rage signaling regulates microrna 155 expression via ap 1 activation in colon cancer
Experimental Cell Research, 2013Co-Authors: Benjamin C. Onyeagucha, Jennifer Hutchison, Erik K. Flemington, Melania E Mercadopimentel, Mark A. NelsonAbstract:Accumulating evidence indicates that elevated S100P promotes the pathogenesis of cancers, including colon cancer. S100P exerts its effects by binding to and activating the Receptor for Advance Glycation End-products (RAGE). The effects of up-regulated S100P/RAGE signaling on cell functions are well documented. Despite these observations, little is known about the downstream targets of S100P/RAGE signaling. In the present study, we demonstrated for the first time that activation of RAGE by S100P regulates oncogenic microRNA-155 (miR-155) expression through Activator Protein-1 (AP-1) stimulation in colon cancer cells. Ectopic S100P up-regulated miR-155 levels in human colon cancer cells. Conversely, knockdown of S100P resulted in a decrease in miR-155 levels. Exogenous S100P induced miR-155 expression, but blockage of the RAGE with anti-RAGE antibody suppressed the induction of miR-155 by exogenous S100P. Attenuation of AP-1 activation through pharmacological inhibition of MEK activation or genetic inhibition of c-Jun activation using dominant negative c-Jun (TAM67) suppressed miR-155 induction by exogenous S100P. Also, S100P treatment stimulated the enrichment of c-Fos, an AP-1 family member, at the miR-155 host gene promoter site. Finally, a functional study demonstrated that miR-155 knockdown decreases colon cancer cell growth, motility, and invasion. Altogether, these data demonstrate that the expression of miR-155 is regulated by S100P and is dependent on RAGE activation and stimulation of AP-1.
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S100P/RAGE signaling regulates microRNA-155 expression via AP-1 activation in colon cancer.
Experimental cell research, 2013Co-Authors: Benjamin C. Onyeagucha, Melania E. Mercado-pimentel, Jennifer Hutchison, Erik K. Flemington, Mark A. NelsonAbstract:Accumulating evidence indicates that elevated S100P promotes the pathogenesis of cancers, including colon cancer. S100P exerts its effects by binding to and activating the Receptor for Advance Glycation End-products (RAGE). The effects of up-regulated S100P/RAGE signaling on cell functions are well documented. Despite these observations, little is known about the downstream targets of S100P/RAGE signaling. In the present study, we demonstrated for the first time that activation of RAGE by S100P regulates oncogenic microRNA-155 (miR-155) expression through Activator Protein-1 (AP-1) stimulation in colon cancer cells. Ectopic S100P up-regulated miR-155 levels in human colon cancer cells. Conversely, knockdown of S100P resulted in a decrease in miR-155 levels. Exogenous S100P induced miR-155 expression, but blockage of the RAGE with anti-RAGE antibody suppressed the induction of miR-155 by exogenous S100P. Attenuation of AP-1 activation through pharmacological inhibition of MEK activation or genetic inhibition of c-Jun activation using dominant negative c-Jun (TAM67) suppressed miR-155 induction by exogenous S100P. Also, S100P treatment stimulated the enrichment of c-Fos, an AP-1 family member, at the miR-155 host gene promoter site. Finally, a functional study demonstrated that miR-155 knockdown decreases colon cancer cell growth, motility, and invasion. Altogether, these data demonstrate that the expression of miR-155 is regulated by S100P and is dependent on RAGE activation and stimulation of AP-1.
