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Hyperactive RAS/PI3-K/MAPK Signaling Cascade in Migration and Adhesion of Nf1 Haploinsufficient Mesenchymal Stem/Progenitor Cells.

Zhou Y, He Y, Sharma R, Xing W, Estwick SA, Wu X, Rhodes SD, Xu M, Yang FC - Int J Mol Sci (2015)

Bottom Line: We previously demonstrated that Nf1 haploinsufficiency in mesenchymal stem/progenitor cells (MSPCs) results in impaired osteoblastic differentiation, which may be associated with the skeletal manifestations in NF1 patients.Nf1(+/-) MSPCs demonstrated increased nuclear-cytoplasmic ratio, increased migration, and increased actin polymerization as compared to wild-type (WT) MSPCs.Nf1(+/-) MSPCs also showed hyperactivation of phosphoinositide 3-kinase (PI3-K) and mitogen activated protein kinase (MAPK) signaling pathways when compared to WT MSPCs, which were both significantly reduced in the presence of their pharmacologic inhibitors, LY294002 and PD0325901, respectively.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020, China. yuanzhou@ihcams.ac.cn.

ABSTRACT
Neurofibromatosis type 1 (NF1) is an autosomal dominant disease caused by mutations in the NF1 tumor suppressor gene, which affect approximately 1 out of 3000 individuals. Patients with NF1 suffer from a range of malignant and nonmalignant manifestations such as plexiform neurofibromas and skeletal abnormalities. We previously demonstrated that Nf1 haploinsufficiency in mesenchymal stem/progenitor cells (MSPCs) results in impaired osteoblastic differentiation, which may be associated with the skeletal manifestations in NF1 patients. Here we sought to further ascertain the role of Nf1 in modulating the migration and adhesion of MSPCs of the Nf1 haploinsufficient (Nf1(+/-)) mice. Nf1(+/-) MSPCs demonstrated increased nuclear-cytoplasmic ratio, increased migration, and increased actin polymerization as compared to wild-type (WT) MSPCs. Additionally, Nf1(+/-) MSPCs were noted to have significantly enhanced cell adhesion to fibronectin with selective affinity for CH271 with an overexpression of its complimentary receptor, CD49e. Nf1(+/-) MSPCs also showed hyperactivation of phosphoinositide 3-kinase (PI3-K) and mitogen activated protein kinase (MAPK) signaling pathways when compared to WT MSPCs, which were both significantly reduced in the presence of their pharmacologic inhibitors, LY294002 and PD0325901, respectively. Collectively, our study suggests that both PI3-K and MAPK signaling pathways play a significant role in enhanced migration and adhesion of Nf1 haploinsufficient MSPCs.

No MeSH data available.


Related in: MedlinePlus

Morphological differences between wild-type (WT) and Nf1 haploinsufficient (Nf1+/−) mesenchymal stem/progenitor cells (MSPCs). (A) Morphology of WT and Nf1+/− MSPCs imaged under 200× amplification by phase contrast microscopy. Cells were stained with 400 nM fluorescein isothiocyanate(FITC)-phalloidin and DAPI; (B) A quantitative comparison of nuclear-cytoplasmic ratio between WT and Nf1+/− MSPCs based on the average ratio of nuclear area/cytoplasm area in 50 cells/field from five different fields. Data are represented as mean ± SD from three batches of MSPCs isolated from individual mice (* p < 0.05 for Nf1+/−vs. WT MSPCs).
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ijms-16-12345-f001: Morphological differences between wild-type (WT) and Nf1 haploinsufficient (Nf1+/−) mesenchymal stem/progenitor cells (MSPCs). (A) Morphology of WT and Nf1+/− MSPCs imaged under 200× amplification by phase contrast microscopy. Cells were stained with 400 nM fluorescein isothiocyanate(FITC)-phalloidin and DAPI; (B) A quantitative comparison of nuclear-cytoplasmic ratio between WT and Nf1+/− MSPCs based on the average ratio of nuclear area/cytoplasm area in 50 cells/field from five different fields. Data are represented as mean ± SD from three batches of MSPCs isolated from individual mice (* p < 0.05 for Nf1+/−vs. WT MSPCs).

Mentions: Nf1+/−MSPCs were noted to have elongated, spindle shaped cytoplasm in comparison to the branched cytoplasm observed in WT MSPCs (Figure 1A). Quantification of this morphological change revealed an increased nuclear-to-cytoplasmic ratio in Nf1+/− MSPCs compared to WT controls (Figure 1B). These findings indicated involvement of neurofibromin in regulating MSPC morphology.


Hyperactive RAS/PI3-K/MAPK Signaling Cascade in Migration and Adhesion of Nf1 Haploinsufficient Mesenchymal Stem/Progenitor Cells.

Zhou Y, He Y, Sharma R, Xing W, Estwick SA, Wu X, Rhodes SD, Xu M, Yang FC - Int J Mol Sci (2015)

Morphological differences between wild-type (WT) and Nf1 haploinsufficient (Nf1+/−) mesenchymal stem/progenitor cells (MSPCs). (A) Morphology of WT and Nf1+/− MSPCs imaged under 200× amplification by phase contrast microscopy. Cells were stained with 400 nM fluorescein isothiocyanate(FITC)-phalloidin and DAPI; (B) A quantitative comparison of nuclear-cytoplasmic ratio between WT and Nf1+/− MSPCs based on the average ratio of nuclear area/cytoplasm area in 50 cells/field from five different fields. Data are represented as mean ± SD from three batches of MSPCs isolated from individual mice (* p < 0.05 for Nf1+/−vs. WT MSPCs).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4490447&req=5

ijms-16-12345-f001: Morphological differences between wild-type (WT) and Nf1 haploinsufficient (Nf1+/−) mesenchymal stem/progenitor cells (MSPCs). (A) Morphology of WT and Nf1+/− MSPCs imaged under 200× amplification by phase contrast microscopy. Cells were stained with 400 nM fluorescein isothiocyanate(FITC)-phalloidin and DAPI; (B) A quantitative comparison of nuclear-cytoplasmic ratio between WT and Nf1+/− MSPCs based on the average ratio of nuclear area/cytoplasm area in 50 cells/field from five different fields. Data are represented as mean ± SD from three batches of MSPCs isolated from individual mice (* p < 0.05 for Nf1+/−vs. WT MSPCs).
Mentions: Nf1+/−MSPCs were noted to have elongated, spindle shaped cytoplasm in comparison to the branched cytoplasm observed in WT MSPCs (Figure 1A). Quantification of this morphological change revealed an increased nuclear-to-cytoplasmic ratio in Nf1+/− MSPCs compared to WT controls (Figure 1B). These findings indicated involvement of neurofibromin in regulating MSPC morphology.

Bottom Line: We previously demonstrated that Nf1 haploinsufficiency in mesenchymal stem/progenitor cells (MSPCs) results in impaired osteoblastic differentiation, which may be associated with the skeletal manifestations in NF1 patients.Nf1(+/-) MSPCs demonstrated increased nuclear-cytoplasmic ratio, increased migration, and increased actin polymerization as compared to wild-type (WT) MSPCs.Nf1(+/-) MSPCs also showed hyperactivation of phosphoinositide 3-kinase (PI3-K) and mitogen activated protein kinase (MAPK) signaling pathways when compared to WT MSPCs, which were both significantly reduced in the presence of their pharmacologic inhibitors, LY294002 and PD0325901, respectively.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020, China. yuanzhou@ihcams.ac.cn.

ABSTRACT
Neurofibromatosis type 1 (NF1) is an autosomal dominant disease caused by mutations in the NF1 tumor suppressor gene, which affect approximately 1 out of 3000 individuals. Patients with NF1 suffer from a range of malignant and nonmalignant manifestations such as plexiform neurofibromas and skeletal abnormalities. We previously demonstrated that Nf1 haploinsufficiency in mesenchymal stem/progenitor cells (MSPCs) results in impaired osteoblastic differentiation, which may be associated with the skeletal manifestations in NF1 patients. Here we sought to further ascertain the role of Nf1 in modulating the migration and adhesion of MSPCs of the Nf1 haploinsufficient (Nf1(+/-)) mice. Nf1(+/-) MSPCs demonstrated increased nuclear-cytoplasmic ratio, increased migration, and increased actin polymerization as compared to wild-type (WT) MSPCs. Additionally, Nf1(+/-) MSPCs were noted to have significantly enhanced cell adhesion to fibronectin with selective affinity for CH271 with an overexpression of its complimentary receptor, CD49e. Nf1(+/-) MSPCs also showed hyperactivation of phosphoinositide 3-kinase (PI3-K) and mitogen activated protein kinase (MAPK) signaling pathways when compared to WT MSPCs, which were both significantly reduced in the presence of their pharmacologic inhibitors, LY294002 and PD0325901, respectively. Collectively, our study suggests that both PI3-K and MAPK signaling pathways play a significant role in enhanced migration and adhesion of Nf1 haploinsufficient MSPCs.

No MeSH data available.


Related in: MedlinePlus