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Expression of genes involved in placental glucose transport and phosphorylation
Abstracts" E P G and R T C Belgtum 1995
COLONY-STIMULATING FACTOR-1 PROVIDES AN AUTOCRINE SIGNAL FOR FIRST TRIMESTER EXTRAVILLOUS TROPHOBLAST CELL PROLIFERATION. G.S. Hamilton t, J.J. Lysiak ~, A.J. Watson ~ and P.K. Lala ~, Departments of Anatomy ~ and Obstetrics and Gynaecology2, University of Western Ontario, London, ON, Canada Colony-stimulating factor (CSF)-I has been localized in a variety of tissues and shown to influence proliferation and differentiation of numerous cell types. Messenger RNA and protein products of CSF-1 and its receptor (c-fms) have been identified in the human placenta and decidua. The present study examined whether CSF-1 and c-fms mRNA are expressed by invasive human first trimester cytotrophoblast cells propagated in culture and whether CSF-1 influences proliferation and/or invasion of these cells. CSF-I mRNA expression was determined by RT-PCR using published primer sets and proliferation was assessed by uptake of tritiated thymidine CH-TdR). Invasion was evaluated by Matrigel invasion assays and Northern blot analysis of mRNA for invasion-associated enzymes as well as their inhibitors. Results revealed that invasive trophoblast express both CSF-1 and c-fms mRNA in culture and that exogenous CSF-1 greatly stimulates the proliferation of these cells under serum-free conditions. CSF-1 neutralizing and c-fins receptor blocking antibodies both abolish the growth stimulatory effects of CSF-1 indicating that CSF-I and c-fms interaction was responsible for these effects. Exogenous CSF-1 failed to influence trophoblast invasiveness, however, Northern blot analysis of mRNA indicated a slight upregulation of 72 kDa type IV collagenase (gelatinase B) as well as its inhibitor (tissue inhibitor of metalloprotease; TIMP-1), Thus, the failure of CSF-1 to alter trophoblast invasiveness appears to result from balanced increases in both invasion-associated enzymes and enzyme inhibitors. These findings suggest that CSF-1 may represent an autocrine growth stimulatory factor for the invasive trophoblast cells in situ with no net effect on their invasiveness. (Supported by the MRC Canada)
EXPRESSION OF GENES INVOLVED IN PLACENTAL GLUCOSE TRANSPORT AND PHOSPHORYLATION. S. H a u g u e l - d e Mouzon, P. Boileau, M. Cafizac, J. G i r a r d . CEREMOD-CNRS, 9 rue J. Hetzel, Meudon, France. T h e t r a n s p o r t of glucose a c r o s s the cell m e m b r a n e a n d its s u b s e q u e n t p h o s p h o r y l a t i o n a r e two c r u c i a l s t e p s for g l u c o s e u t i l i z a t i o n . T h e s e p r o c e s s e s i n v o l v e two d i f f e r e n t gene f a m i l i e s encoding the facilitative glucose t r a n s p o r t e r proteins (GLUT 1-5) a n d the h e x o k i n a s e s ( H K I-IV). The aim of this s t u d y was to c h a r a c t e r i z e the r e l a t i v e expression of these genes in the placenta. T h e t e m p o r a l e x p r e s s i o n of the h e x o k i n a s e isoforms H K I , H K I I I a n d H K I I as well as the glucose t r a n s p o r t e r s GLUT1, G L U T 3 a n d G L U T 4 was i n v e s t i g a t e d d u r i n g the l a s t week of p r e g n a n c y in the r a t ( d a y 14-21). H K I , H K I I a n d H K I I I m R N A s were r e a d i l y d e t e c t e d b e t w e e n d a y 14 a n d 21. G L U T 1 , G L U T 3 a n d G L U T 4 w e r e also e x p r e s s e d d u r i n g this period. However, only GLUT-3 gene e x p r e s s i o n v a r i e d as a function of g e s t a t i o n a l age, exhibiting a 3-fold i n c r e a s e between day 14 and 21. T h e r e g u l a t i o n of H K s a n d G L U T s gene expression was studied in a pathological model of feto-placental growth associated with p l a c e n t a l m a c r o s o m i a (severe i n s u l i n o p e n i c m a t e r n a l diabetes). While G L U T 1 a n d H K s m R N A levels r e m a i n e d u n c h a n g e d , G L U T 4 a n d G L U T 3 m R N A levels i n c r e a s e d in m a c r o s o m i c placentas. T h e s e d a t a s u g g e s t t h a t the r e g u l a t i o n of p l a c e n t a l glucose utilization m i g h t not involve a strict functional p a i r i n g of glucose t r a n s p o r t and phosphorylation.
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COLONY-STIMULATING FACTOR-1 PROVIDES AN AUTOCRINE SIGNAL FOR FIRST TRIMESTER EXTRAVILLOUS TROPHOBLAST CELL PROLIFERATION. G.S. Hamilton t, J.J. Lysiak ~, A.J. Watson ~ and P.K. Lala ~, Departments of Anatomy ~ and Obstetrics and Gynaecology2, University of Western Ontario, London, ON, Canada Colony-stimulating factor (CSF)-I has been localized in a variety of tissues and shown to influence proliferation and differentiation of numerous cell types. Messenger RNA and protein products of CSF-1 and its receptor (c-fms) have been identified in the human placenta and decidua. The present study examined whether CSF-1 and c-fms mRNA are expressed by invasive human first trimester cytotrophoblast cells propagated in culture and whether CSF-1 influences proliferation and/or invasion of these cells. CSF-I mRNA expression was determined by RT-PCR using published primer sets and proliferation was assessed by uptake of tritiated thymidine CH-TdR). Invasion was evaluated by Matrigel invasion assays and Northern blot analysis of mRNA for invasion-associated enzymes as well as their inhibitors. Results revealed that invasive trophoblast express both CSF-1 and c-fms mRNA in culture and that exogenous CSF-1 greatly stimulates the proliferation of these cells under serum-free conditions. CSF-1 neutralizing and c-fins receptor blocking antibodies both abolish the growth stimulatory effects of CSF-1 indicating that CSF-I and c-fms interaction was responsible for these effects. Exogenous CSF-1 failed to influence trophoblast invasiveness, however, Northern blot analysis of mRNA indicated a slight upregulation of 72 kDa type IV collagenase (gelatinase B) as well as its inhibitor (tissue inhibitor of metalloprotease; TIMP-1), Thus, the failure of CSF-1 to alter trophoblast invasiveness appears to result from balanced increases in both invasion-associated enzymes and enzyme inhibitors. These findings suggest that CSF-1 may represent an autocrine growth stimulatory factor for the invasive trophoblast cells in situ with no net effect on their invasiveness. (Supported by the MRC Canada)
EXPRESSION OF GENES INVOLVED IN PLACENTAL GLUCOSE TRANSPORT AND PHOSPHORYLATION. S. H a u g u e l - d e Mouzon, P. Boileau, M. Cafizac, J. G i r a r d . CEREMOD-CNRS, 9 rue J. Hetzel, Meudon, France. T h e t r a n s p o r t of glucose a c r o s s the cell m e m b r a n e a n d its s u b s e q u e n t p h o s p h o r y l a t i o n a r e two c r u c i a l s t e p s for g l u c o s e u t i l i z a t i o n . T h e s e p r o c e s s e s i n v o l v e two d i f f e r e n t gene f a m i l i e s encoding the facilitative glucose t r a n s p o r t e r proteins (GLUT 1-5) a n d the h e x o k i n a s e s ( H K I-IV). The aim of this s t u d y was to c h a r a c t e r i z e the r e l a t i v e expression of these genes in the placenta. T h e t e m p o r a l e x p r e s s i o n of the h e x o k i n a s e isoforms H K I , H K I I I a n d H K I I as well as the glucose t r a n s p o r t e r s GLUT1, G L U T 3 a n d G L U T 4 was i n v e s t i g a t e d d u r i n g the l a s t week of p r e g n a n c y in the r a t ( d a y 14-21). H K I , H K I I a n d H K I I I m R N A s were r e a d i l y d e t e c t e d b e t w e e n d a y 14 a n d 21. G L U T 1 , G L U T 3 a n d G L U T 4 w e r e also e x p r e s s e d d u r i n g this period. However, only GLUT-3 gene e x p r e s s i o n v a r i e d as a function of g e s t a t i o n a l age, exhibiting a 3-fold i n c r e a s e between day 14 and 21. T h e r e g u l a t i o n of H K s a n d G L U T s gene expression was studied in a pathological model of feto-placental growth associated with p l a c e n t a l m a c r o s o m i a (severe i n s u l i n o p e n i c m a t e r n a l diabetes). While G L U T 1 a n d H K s m R N A levels r e m a i n e d u n c h a n g e d , G L U T 4 a n d G L U T 3 m R N A levels i n c r e a s e d in m a c r o s o m i c placentas. T h e s e d a t a s u g g e s t t h a t the r e g u l a t i o n of p l a c e n t a l glucose utilization m i g h t not involve a strict functional p a i r i n g of glucose t r a n s p o r t and phosphorylation.
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