Methylation of eukaryotic elongation factor 2 induced by basic fibroblast growth factor via mitogen-activated protein kinase

Protein arginine methylation is important for a variety of cellular processes including transcriptional regulation, mRNA splicing, DNA repair, nuclear/cytoplasmic shuttling and various signal transduction pathways. However, the role of arginine methylation in protein biosynthesis and the extracellular signals that control arginine methylation are not fully understood. Basic fibroblast growth factor (bFGF) has been identified as a potent stimulator of myofibroblast dedifferentiation into fibroblasts. We demonstrated that symmetric arginine dimethylation of eukaryotic elongation factor 2 (eEF2) is induced by bFGF without the change in the expression level of eEF2 in mouse embryo fibroblast NIH3T3 cells. The eEF2 methylation is preceded by ras-raf-mitogen-activated protein kinase kinase (MEK)-extracellular signal-regulated kinase (ERK1/2)-p21(Cip/WAF1) activation, and suppressed by the mitogen-activated protein kinase (MAPK) inhibitor PD98059 and p21(Cip/WAF1) short interfering RNA (siRNA). We determined that protein arginine methyltransferase 7 (PRMT7) is responsible for the methylation, and that PRMT5 acts as a coordinator. Collectively, we demonstrated that eEF2, a key factor involved in protein translational elongation is symmetrically arginine-methylated in a reversible manner, being regulated by bFGF through MAPK signaling pathway.

Methylation of eukaryotic elongation factor 2 induced by basic fibroblast growth factor via mitogen-activated protein kinase

Protein arginine methylation is important for a variety of cellular processes including transcriptional regulation, mRNA splicing, DNA repair, nuclear/cytoplasmic shuttling and various signal transduction pathways. However, the role of arginine methylation in protein biosynthesis and the extracellular signals that control arginine methylation are not fully understood. Basic fibroblast growth factor (bFGF) has been identified as a potent stimulator of myofibroblast dedifferentiation into fibroblasts. We demonstrated that symmetric arginine dimethylation of eukaryotic elongation factor 2 (eEF2) is induced by bFGF without the change in the expression level of eEF2 in mouse embryo fibroblast NIH3T3 cells. The eEF2 methylation is preceded by ras-raf-mitogen-activated protein kinase kinase (MEK)-extracellular signal-regulated kinase (ERK1/2)-p21(Cip/WAF1) activation, and suppressed by the mitogen-activated protein kinase (MAPK) inhibitor PD98059 and p21(Cip/WAF1) short interfering RNA (siRNA). We determined that protein arginine methyltransferase 7 (PRMT7) is responsible for the methylation, and that PRMT5 acts as a coordinator. Collectively, we demonstrated that eEF2, a key factor involved in protein translational elongation is symmetrically arginine-methylated in a reversible manner, being regulated by bFGF through MAPK signaling pathway.

Characteristics of amniotic fluid derived stem cells with trisomy 21 / 대한산부인과학회지

OBJECTIVE: To assess molecular markers of amniotic fluid derived stem cells (AFSCs) in aspects of increased neurological deficit in Down syndrome. METHODS: Amniotic fluid samples through amniocentesis for prenatal diagnosis from four mid trimester pregnancies; by routine chromosomal analysis, two of them were trisomy 21 (Down syndrome) and others were normal, were selected after informed consent. Cells from two-stage culture protocol were assayed; morphology through phase contrast microscopy, chromosomal analysis, reverse transcriptase-polymerase chain reaction and Western blot analysis. RESULTS: AFSCs were highly proliferative in subcultures and most of them were mononuclear, fibroblast-like, fusiform cells. There were also a few ovoid cells. The chromosomal analysis of amniotic fluid stem cells was identical to that of amniotic fluid cells. Two of four samples were 47,XX,+21, others were 46,XX. Of the proteins related to Down syndrome, the expression of S100beta were increased in AFSCs of Down syndrome, COL6A1 (Collagen IV, alpha 1) was down-regulated in them and insulin like growth factor binding protein-1 was expressed in all AFSCs. Stem cell markers were expressed heterogeneously. Oct4 (POU5F1), nanog, and SOX2 (sex determining region Y) were expressed in both groups. But c-Kit was not expressed in AFSCs of Down syndrome. The neural cell marker, neuron specific enolase was detected in both groups. Other neural cell markers, microtubule associated protein 2, glial fibrillary acidic protein were undetectable in ASFCs of Down syndrome. Bcl-2 gene family proteins related with apoptosis were assayed. The expression of Bcl-XL was increased in Down syndrome more than in normal pregnancy. Bcl-2 and BID were expressed in all AFSCs and Bax was down-regulated in Down syndrome. CONCLUSION: AFSCs are an excellent choice for many future tissue engineering strategies and cell based therapies. Analysis of molecular features of AFSCs from normal and Down syndrome will provide the basis of further experimental study.

A Case of Prenatal Diagnosis of Thoracic Ectopia Cordis / 대한산부인과학회잡지

Ectopia cordis is defined as a congenital malposition of the heart partially or completely outside the thorax and often associated with sternal and congenital heart defects:surgical repair is generally unsuccessful because of the magnitude of the deformity and the associat-ed intracardiac anormalies. Four types of ectopia cordis are described : cervical, thoracic, abdominal and thoracoa- bdominal. Cervical and thoracic type are often fatal within days, because the heart is expo- sed and malformed. Abdominal type carries a better prognosis because cardiac abnormalities are less often found. The prognosis of thoraco-abdominal type mainly depends on the pre- sence of intracardiac abnormalities. We have experienced a case of thoracic ectopia cordis at 25 weeks' gestation by ultra- sonography, so present the case and the review with literature briefly.