scholarly journals Signalling pathways involved in the cooperative effects of ovine and murine GDF9+BMP15-stimulated thymidine uptake by rat granulosa cells

Reproduction ◽  
2011 ◽  
Vol 142 (1) ◽  
pp. 123-131 ◽  
Author(s):  
Karen L Reader ◽  
Derek A Heath ◽  
Stan Lun ◽  
C Joy McIntosh ◽  
Andrea H Western ◽  
...  
Keyword(s):  
Granulosa Cells ◽  
Kinase Inhibitor ◽  
Mapk Pathway ◽  
Molecular Complexes ◽  
Nuclear Factor Κb ◽  
Mitogen Activated Protein Kinase ◽  
Molecular Forms ◽  
Signalling Pathways ◽  
Thymidine Uptake ◽  
Cooperative Effects

Growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) are oocyte-secreted factors known to be involved in regulating the proliferation and differentiation of granulosa cells during follicular growth. The aims of this study were to determine the signalling pathways used by recombinant forms of murine and ovine GDF9 and BMP15 in combination (GDF9+BMP15) and the molecular complexes formed by combinations of these factors. Differences in the molecular forms of combinations of murine and ovine GDF9+BMP15 were observed by western blot analysis. Ovine GDF9+BMP15-stimulated 3H-thymidine uptake was completely blocked by SMAD2/3 and nuclear factor-κB pathway inhibitors and partially blocked by a p38-mitogen-activated protein kinase (MAPK) inhibitor. Thymidine uptake by murine GDF9+BMP15 was reduced by the SMAD2/3 and extracellular signal-regulated kinase-MAPK pathway inhibitors and increased after addition of a c-Jun N-terminal kinase inhibitor. Stimulation of 3H-thymidine uptake by GDF9+BMP15 from either species was not affected by the SMAD1/5/8 pathway inhibitor. In conclusion, both murine and ovine GDF9+BMP15-stimulated thymidine incorporation in rat granulosa cells was dependent on the SMAD2/3 signalling pathway but not the SMAD1/5/8 pathway. Divergence in the non-SMAD signalling pathways used by murine and ovine GDF9+BMP15 was also evident and may be due to the differences observed in the molecular complexes formed by these factors. These results are consistent with the hypothesis that the disparate cooperative functions of GDF9 and BMP15 in different species are mediated by divergent non-SMAD signalling pathways.

272. Signalling pathways involved in mouse GDF9 and BMP15 stimulated thymidine uptake by rat granulosa cells

2008 ◽  
Vol 20 (9) ◽  
pp. 72
Author(s):  
K. L. Reader ◽  
C. J. McIntosh ◽  
J. L. Juengel
Keyword(s):  
P38 Mapk ◽  
Granulosa Cells ◽  
Molecular Mechanisms ◽  
Thymidine Incorporation ◽  
Fold Increase ◽  
Fertility Control ◽  
Mitogen Activated Protein Kinase ◽  
Thymidine Uptake ◽  
Cooperative Effects ◽  
Mitogen Activated Protein

The oocyte-secreted factors growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) are essential for ovarian follicular growth and development. Understanding the molecular mechanisms of these factors could assist with the development of future products for fertility control. Thymidine uptake by rat granulosa cells is stimulated cooperatively by GDF9 and BMP15. Inhibitors of the activin receptor-like kinase (ALK) 4,5,7 and the nuclear factor kappaB (NFKB) second messenger pathways block ovine GDF9 and BMP15 stimulated thymidine incorporation. The ALK 4,5,7 receptor pathway is known to be essential for the cooperative effects of mouse (m)GDF9 and mBMP15 on thymidine incorporation but the role of other pathways has yet to be determined, which was the focus of this study. Inhibitors of NFKB (Sn50; 10µg/mL), ALK 2,3,6 receptor (Dorsomorphin; 1µM), p38 mitogen-activated protein kinase (p38 MAPK; SB239063; 5 µM) and c-Jun-N-terminal kinase (JNK; TAT-TI-JIP153–163; 5 µM) pathways were each cultured with recombinant mGDF9 (25 ng/mL) and mBMP15 (6 ng/mL) in a rat granulosa cell [3H]-thymidine bioassay. The p38 MAPK inhibitor caused partial inhibition of thymidine uptake but this appeared to be non-specific as a similar level of suppression was observed in the control cultures. Neither the ALK 2,3,6 receptor nor the NFKB pathway inhibitors had any effect on mGDF9 and mBMP15 stimulated thymidine uptake. The JNK inhibitor showed a 1.7-fold increase in stimulation above the mGDF9 and mBMP15 effect (P < 0.01) but a similar stimulation was also observed in some controls. This differs from the results observed with ovine GDF9 and BMP15 where thymidine uptake was completely blocked by the NFKB inhibitor and the JNK inhibitor had no effect. In conclusion, the molecular mechanisms of GDF9 and BMP15 function are dependent on the species of origin of the growth factor and therefore caution is needed when extrapolating findings from one species to another.

scholarly journals Ghrelin exerts a proliferative effect on a rat pituitary somatotroph cell line via the mitogen-activated protein kinase pathway

2004 ◽  
pp. 233-240 ◽  
Author(s):  
AM Nanzer ◽  
S Khalaf ◽  
AM Mozid ◽  
RC Fowkes ◽  
MV Patel ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Protein Kinase ◽  
Cell Line ◽  
Kinase Inhibitor ◽  
Thymidine Incorporation ◽  
Mapk Pathway ◽  
Mitogen Activated Protein Kinase ◽  
Gh3 Cells ◽  
Rat Pituitary ◽  
Mitogen Activated Protein

OBJECTIVES: Ghrelin is a brain-gut peptide with GH-releasing and appetite-inducing activities and a widespread tissue distribution. Ghrelin is the endogenous ligand of the GH secretagogue receptor type 1a (GHS-R1a), and both ghrelin and the GHS-R1a are expressed in the pituitary. There are conflicting data regarding the effects of ghrelin on cell proliferation. A positive effect on proliferation and activation of the mitogen-activated protein kinase (MAPK) pathway has been found in hepatoma, adipose, cardiomyocyte and prostate cell lines. However, ghrelin has also been shown to have anti-proliferative effects on breast, lung and thyroid cell lines. We therefore examined the effect of ghrelin on the rat pituitary cell line GH3. METHODS: RT-PCR was used for the detection of GHS-R1a and pre-proghrelin mRNA expression in GH3 cells. The effect of ghrelin on cell proliferation was studied using [(3)H]thymidine incorporation; cell counting and the activation of the MAPK pathway were studied using immunoblotting and inhibitors of the extracellular signal-regulated kinase 1 and 2 (ERK 1/2), protein kinase C (PKC) and tyrosine phosphatase pathways. RESULTS: GHS-R1a and ghrelin mRNA expression were detected in GH3 cells. Ghrelin, at 10(-10) to 10(-6) M concentrations, significantly increased [(3)H]thymidine incorporation (at 10(-9) M, 183+/-13% (means+/-s.e.m.) compared with untreated controls), while 12-phorbol 13-myristate acetate (PMA) at 10(-7) M (used as a positive control) caused a 212+/-14% increase. A reproducible stimulatory effect of desoctanoyl ghrelin was also observed on [(3)H]thymidine incorporation (135+/-5%; P<0.01 at 10(-9) M compared with control), as well as on the cell count (control 6.8 x 10(4)+/-8.7 x 10(3) cells/ml vs desoctanoyl ghrelin (10(-9) M) 1.04 x 10(5)+/-7.5 x 10(3) cells/ml; P<0.01). Ghrelin caused a significant increase in phosphorylated ERK 1/2 in immunoblotting, while desoctanoyl ghrelin showed a smaller but also significant stimulatory effect. The positive effect of ghrelin and desoctanoyl ghrelin on [(3)H]thymidine incorporation was abolished by the MAPK kinase inhibitor U0126, the PKC inhibitor GF109203X and the tyrosine kinase inhibitor tyrphostin 23, suggesting that the ghrelin-induced cell proliferation of GH3 cells is mediated both via a PKC-MAPK-dependent pathway and via a tyrosine kinase-dependent pathway. This could also be clearly demonstrated by Western blot analysis, where a transient increase in ERK 1/2 phosphorylation by ghrelin was attenuated by all three inhibitors. CONCLUSION: We have shown a novel role for ghrelin in stimulating the proliferation of a somatotroph pituitary tumour cell line, suggesting that ERK activation is involved in mediating the effects of ghrelin on cell proliferation. Desoctanoyl ghrelin showed a similar effect. As ghrelin has been shown to be expressed in both normal and adenomatous pituitary tissue, locally produced ghrelin may play a role in pituitary tumorigenesis via an autocrine/paracrine pathway.

scholarly journals Regulation of PDGFR-α in rat pulmonary myofibroblasts by staurosporine

2001 ◽  
Vol 280 (2) ◽  
pp. L354-L362 ◽  
Author(s):  
Pamela M. Lindroos ◽  
Yi-Zhe Wang ◽  
Annette B. Rice ◽  
James C. Bonner
Keyword(s):  
Kinase Inhibitors ◽  
Kinase Inhibitor ◽  
Protein A ◽  
Nuclear Factor Κb ◽  
Mitogen Activated Protein Kinase ◽  
Specific Gene ◽  
Autocrine Loop ◽  
P38 Inhibitor ◽  
Mitogen Activated Protein

Upregulation of the platelet-derived growth factor (PDGF) receptor-α (PDGFR-α) is a mechanism of myofibroblast hyperplasia during pulmonary fibrosis. We previously identified interleukin (IL)-1β as a major inducer of the PDGFR-α in rat pulmonary myofibroblasts in vitro. In this study, we report that staurosporine, a broad-spectrum kinase inhibitor, upregulates PDGFR-α gene expression and protein. A variety of other kinase inhibitors did not induce PDGFR-α expression. Staurosporine did not act via an IL-1β autocrine loop because the IL-1 receptor antagonist protein did not block staurosporine-induced PDGFR-α expression. Furthermore, staurosporine did not activate a variety of signaling molecules that were activated by IL-1β, including nuclear factor-κB, extracellular signal-regulated kinase, and c-Jun NH2-terminal kinase. However, both staurosporine- and IL-1β-induced phosphorylation of p38 mitogen-activated protein kinase and upregulation of PDGFR-α by these two agents was inhibited by the p38 inhibitor SB-203580. Finally, staurosporine inhibited basal and PDGF-stimulated mitogenesis over the same concentration range that induced PDGFR-α expression. Collectively, these data demonstrate that staurosporine is a useful tool for elucidating the signaling mechanisms that regulate PDGFR expression in lung connective tissue cells and possibly for evaluating the role of the PDGFR-α as a growth arrest-specific gene.

Phosphorylation of Argonaute 2 at serine-387 facilitates its localization to processing bodies

2008 ◽  
Vol 413 (3) ◽  
pp. 429-436 ◽  
Author(s):  
Yan Zeng ◽  
Heidi Sankala ◽  
Xiaoxiao Zhang ◽  
Paul R. Graves
Keyword(s):  
Protein Kinase ◽  
P38 Mapk ◽  
Kinase Inhibitor ◽  
Mapk Pathway ◽  
Phosphorylation Site ◽  
Mitogen Activated Protein Kinase ◽  
Processing Bodies ◽  
Mitogen Activated Protein

Ago (Argonaute) proteins are essential effectors of RNA-mediated gene silencing. To explore potential regulatory mechanisms for Ago proteins, we examined the phosphorylation of human Ago2. We identified serine-387 as the major Ago2 phosphorylation site in vivo. Phosphorylation of Ago2 at serine-387 was significantly induced by treatment with sodium arsenite or anisomycin, and arsenite-induced phosphorylation was inhibited by a p38 MAPK (mitogen-activated protein kinase) inhibitor, but not by inhibitors of JNK (c-Jun N-terminal kinase) or MEK [MAPK/ERK (extracellular-signal-regulated kinase) kinase]. MAPKAPK2 (MAPK-activated protein kinase-2) phosphorylated bacterially expressed full-length human Ago2 at serine-387 in vitro, but not the S387A mutant. Finally, mutation of serine-387 to an alanine residue or treatment of cells with a p38 MAPK inhibitor reduced the localization of Ago2 to processing bodies. These results suggest a potential regulatory mechanism for RNA silencing acting through Ago2 serine-387 phosphorylation mediated by the p38 MAPK pathway.

Modulation of granulocyte apoptosis can influence the resolution of inflammation

2007 ◽  
Vol 35 (2) ◽  
pp. 288-291 ◽  
Author(s):  
A.G. Rossi ◽  
J.M. Hallett ◽  
D.A. Sawatzky ◽  
M.M. Teixeira ◽  
C. Haslett
Keyword(s):  
Kinase Inhibitor ◽  
Nuclear Factor Κb ◽  
Mitogen Activated Protein Kinase ◽  
Apoptotic Cells ◽  
Resolution Of Inflammation ◽  
Mitogen Activated Protein ◽  
Apoptotic Pathways ◽  
Phosphoinositide 3 Kinase

Apoptosis of granulocytes and the subsequent clearance of apoptotic cells are important processes for the successful resolution of inflammation. Signalling pathways, including those involving NF-κB (nuclear factor κB), MAPK (mitogen-activated protein kinase) and PI3K (phosphoinositide 3-kinase) have been shown to be key regulators of inflammatory cell survival and apoptosis in vitro. In addition, manipulation of such pathways in vivo has indicated that they also play a role in the resolution of inflammation. Furthermore, manipulation of proteins directly involved in the control of apoptosis, such as Bcl-2 family members and caspases, can be targeted in vivo to influence inflammatory resolution. Recently, it has been shown that CDK (cyclin-dependent kinase) inhibitor drugs induce caspase-dependent human neutrophil apoptosis possibly by altering levels of the anti-apoptotic Bcl-2 family member, Mcl-1. Importantly, CDK inhibitor drugs augment the resolution of established ‘neutrophil-dominant’ inflammation by promoting apoptosis of neutrophils. Thus manipulation of apoptotic pathways, together with ensuring macrophage clearance of apoptotic cells, appears to be a viable pharmacological target for reducing established inflammation.

scholarly journals Growth factor regulation of hyaluronan synthesis and degradation in human dermal fibroblasts: importance of hyaluronan for the mitogenic response of PDGF-BB

2007 ◽  
Vol 404 (2) ◽  
pp. 327-336 ◽  
Author(s):  
Lingli Li ◽  
Trias Asteriou ◽  
Berit Bernert ◽  
Carl-Henrik Heldin ◽  
Paraskevi Heldin
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Fold Increase ◽  
Nuclear Factor Κb ◽  
Transforming Growth Factor Β1 ◽  
Dermal Fibroblasts ◽  
Mitogen Activated Protein Kinase ◽  
Signalling Pathways ◽  
Human Dermal Fibroblasts ◽  
High Level

The glycosaminoglycan hyaluronan is important in many tissuerepair processes. We have investigated the synthesis of hyaluronan in a panel of cell lines of fibroblastic and epithelial origin in response to PDGF (platelet-derived growth factor)-BB and other growth factors. Human dermal fibroblasts exhibited the highest hyaluronan-synthesizing activity in response to PDGF-BB. Analysis of HAS (hyaluronan synthase) and HYAL (hyaluronidase) mRNA expression showed that PDGF-BB treatment induced a 3-fold increase in the already high level of HAS2 mRNA, and increases in HAS1 and HYAL1 mRNA, whereas the levels of HAS3 and HYAL2 mRNA were not affected. Furthermore, PDGF-BB also increased the amount and activity of HAS2 protein, but not of HYAL1 and HYAL2 proteins. Using inhibitors for MEK1/2 [MAPK (mitogen-activated protein kinase)/ERK (extracellular-signal-regulated kinase) kinase 1/2] (U0126) and for PI3K (phosphoinositide 3-kinase) (LY294002), as well as the SN50 inhibitor, which prevents translocation of the active NF-κB (nuclear factor κB) to the nucleus, we observed a complete inhibition of both HAS2 transcriptional activity and hyaluronan synthesis, whereas inhibitors of other signalling pathways were without any significant effect. TGF-β1 (transforming growth factor-β1) did not increase the activity of hyaluronan synthesis in dermal fibroblasts, but increased the activity of HYALs. Importantly, inhibition of hyaluronan binding to its receptor CD44 by the monoclonal antibody Hermes-1, inhibited PDGF-BB-stimulated [3H]thymidine incorporation of dermal fibroblasts. We conclude that the ERK MAPK and PI3K signalling pathways are necessary for the regulation of hyaluronan synthesis by PDGF-BB, and that prevention of its binding to CD44 inhibits PDGF-BB-induced cell growth.

scholarly journals RecurrentNRASmutations in pulmonary Langerhans cell histiocytosis

2016 ◽  
Vol 47 (6) ◽  
pp. 1785-1796 ◽  
Author(s):  
Samia Mourah ◽  
Alexandre How-Kit ◽  
Véronique Meignin ◽  
Dominique Gossot ◽  
Gwenaël Lorillon ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Lung Tissue ◽  
Langerhans Cell Histiocytosis ◽  
Kinase Inhibitor ◽  
Mapk Pathway ◽  
Univariate Analysis ◽  
Langerhans Cell ◽  
Mitogen Activated Protein Kinase ◽  
Normal Lung ◽  
Pulmonary Langerhans Cell Histiocytosis

The mitogen-activated protein kinase (MAPK) pathway is constantly activated in Langerhans cell histiocytosis (LCH). Mutations of the downstream kinasesBRAFandMAP2K1mediate this activation in a subset of LCH lesions. In this study, we attempted to identify other mutations which may explain the MAPK activation in nonmutatedBRAFandMAP2K1LCH lesions.We analysed 26 pulmonary and 37 nonpulmonary LCH lesions for the presence ofBRAF,MAP2K1,NRASandKRASmutations. Grossly normal lung tissue from 10 smoker patients was used as control. Patient spontaneous outcomes were concurrently assessed.BRAFV600Emutations were observed in 50% and 38% of the pulmonary and nonpulmonary LCH lesions, respectively. 40% of pulmonary LCH lesions harbouredNRASQ61K/Rmutations, whereas noNRASmutations were identified in nonpulmonary LCH biopsies or in lung tissue control. In seven out of 11NRASQ61K/R-mutated pulmonary LCH lesions,BRAFV600Emutations were also present. Separately genotyping each CD1a-positive area from the same pulmonary LCH lesion demonstrated that these concurrentBRAFandNRASmutations were carried by different cell clones.NRASQ61K/Rmutations activated both the MAPK and AKT (protein kinase B) pathways. In the univariate analysis, the presence of concurrentBRAFV600EandNRASQ61K/Rmutations was significantly associated with patient outcome.These findings highlight the importance ofNRASgenotyping of pulmonary LCH lesions because the use of BRAF inhibitors in this context may lead to paradoxical disease progression. These patients might benefit from MAPK kinase inhibitor-based treatments.

scholarly journals Identification of pathways modulating vemurafenib resistance in melanoma cells via a genome-wide CRISPR/Cas9 screen

2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Corinna Jie Hui Goh ◽  
Jin Huei Wong ◽  
Chadi El Farran ◽  
Ban Xiong Tan ◽  
Cynthia R Coffill ◽  
...  
Keyword(s):  
Kinase Inhibitor ◽  
Mapk Pathway ◽  
Enrichment Analysis ◽  
Melanoma Cells ◽  
Mitogen Activated Protein Kinase ◽  
Braf V600e ◽  
Genome Wide ◽  
A Genome ◽  
Mitogen Activated Protein ◽  
Genome Scale

Abstract Vemurafenib is a BRAF kinase inhibitor (BRAFi) that is used to treat melanoma patients harboring the constitutively active BRAF-V600E mutation. However, after a few months of treatment patients often develop resistance to vemurafenib leading to disease progression. Sequence analysis of drug-resistant tumor cells and functional genomic screens has identified several genes that regulate vemurafenib resistance. Reactivation of mitogen-activated protein kinase (MAPK) pathway is a recurrent feature of cells that develop resistance to vemurafenib. We performed a genome-scale CRISPR-based knockout screen to identify modulators of vemurafenib resistance in melanoma cells with a highly improved CRISPR sgRNA library called Brunello. We identified 33 genes that regulate resistance to vemurafenib out of which 14 genes have not been reported before. Gene ontology enrichment analysis showed that the hit genes regulate histone modification, transcription and cell cycle. We discuss how inactivation of hit genes might confer resistance to vemurafenib and provide a framework for follow-up investigations.

Sign in / Sign up

Export Citation Format

Share Document