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Contractile proteins isoforms in placental vessels
A.9
Abstracts
EXPRESSION OF EXTRACELLULAR MATRIX MOLECULES RELATED TO PLACENTAL DEVELOPMENT. M. Castellucci*, C. Crescimanno*, J. M0hlhauser*, H.G.Frank*, P.Kaufmann* and L Zardi**, Department of Anatomy*, Technical University of Aachen, Germany; Lab. of Cell Biology**, National Cancer Institute, Genoa, Italy. Extracellular matrix plays a pivotal role in morphogenetic processes. The human placenta is a rapidly developing organ characterized by tissue remodelling, angiogenesis, cell differentiation, and invasion of the uterine wall. To gain insight into the role of some extracellular matrix molecules in the development of this organ, we have studied the expression of flbronectin isoforms, lamimin, collagen IV, some proteoglycans as heparan sulphate and chondroitin sulphate as well as of adhesion molecules as E-cadherln. Immunostaining was performed on kryostat and paraffin sections. The results show that fibronectins were expressed In the villous stroma, particularly around the vessels and that the oncofetal isoform was highly expressed in the distal part of cell islands and cell columns where the extravillous trophoblastic cells were E-cadherin negative. The villous stroma showed also a positive reaction for lamlnin and collagen IV. For most of the villi this reaction was not strictly confined to the basement membranes only, but rather scattered throughout the villous core. These molecules were also present together with heparan sulfate in the distal part of cell islands and cell columns, between the epithelial cells. In addition, the basement membrane underlying the cell Islands and cell columns frequently showed a very strong expression of laminin and collagen IV. These data suggest that extracellular matrix molecules interact during placental development and are specially involved in proliferative and differentiative processes of mesenchymal cells and trophoblast.
CONTRACTILE PROTEINS ISOFORMS Kac~mi, F. M o n d o n , T. Fournier Baudelocque, Paris, France.
IN and
PLACENTAL F. F e r r Y .
VESSELS. INSERM
F. U
Cavaill6, A. 361, Maternit~
Vascular resistance is known to be higher in placental villosities than in umbilical arteries (Thomas and Tulenko 1979). The contractile apparatus of umbilical and chorionic arteries and veins 9 as w e l l as of stem villi vessels (SVV), was studied in order to check if either a gradient of myosin or actin, or differences in their isoforms could be involved in m o d u l a t i n g the blood pressure in these different vessels. Mono and two dimensional electophoresis gel systems were used to q u a n t i f y and identify actin and myosin isoforms in e a c h type of v e s s e l s obtained by microdissection of human term placentae. In vascular smooth muscle, the actomyosin quantity (33,8 • 16,5 pg/mg tissu) was found to be high and identical at all the placental levels, with an high ratio (8.8 • 2.4) of actin/myosin. Three isotypes of myosin heavy chains (MHC) were detected i n all the vessel types, with a predominance of the smooth muscle (SM) types (SMI and SM2) in umbilical and chorionic vessels whereas the nonmuscle (NM) type was maJoritary in SVV. A gradient of SMI was found, diminishing from umbilical vessels to SVV, the inverse being found for
the
NM
isoform.
Three
9 ~ NM and y umbilical and
(SM+NM). chorionic
in
actin
SVV.
a
SM
was
isoforms
of
Here again, the vessels whereas the
predominant
actin SM the form
were
also
isoforms NM form in
detected:
~ SM
predomined in was majoritary
arteries,
whereas
a
and y actin were equivalent in veins. One can speculate that these differences in contractile protein isoforms distribution at different levels of placental vessels may contribute to establish the gradient of the blood pressure, via differences in actomyosin activity. This work was supported b y G E R P and INSERM.
Abstracts
EXPRESSION OF EXTRACELLULAR MATRIX MOLECULES RELATED TO PLACENTAL DEVELOPMENT. M. Castellucci*, C. Crescimanno*, J. M0hlhauser*, H.G.Frank*, P.Kaufmann* and L Zardi**, Department of Anatomy*, Technical University of Aachen, Germany; Lab. of Cell Biology**, National Cancer Institute, Genoa, Italy. Extracellular matrix plays a pivotal role in morphogenetic processes. The human placenta is a rapidly developing organ characterized by tissue remodelling, angiogenesis, cell differentiation, and invasion of the uterine wall. To gain insight into the role of some extracellular matrix molecules in the development of this organ, we have studied the expression of flbronectin isoforms, lamimin, collagen IV, some proteoglycans as heparan sulphate and chondroitin sulphate as well as of adhesion molecules as E-cadherln. Immunostaining was performed on kryostat and paraffin sections. The results show that fibronectins were expressed In the villous stroma, particularly around the vessels and that the oncofetal isoform was highly expressed in the distal part of cell islands and cell columns where the extravillous trophoblastic cells were E-cadherin negative. The villous stroma showed also a positive reaction for lamlnin and collagen IV. For most of the villi this reaction was not strictly confined to the basement membranes only, but rather scattered throughout the villous core. These molecules were also present together with heparan sulfate in the distal part of cell islands and cell columns, between the epithelial cells. In addition, the basement membrane underlying the cell Islands and cell columns frequently showed a very strong expression of laminin and collagen IV. These data suggest that extracellular matrix molecules interact during placental development and are specially involved in proliferative and differentiative processes of mesenchymal cells and trophoblast.
CONTRACTILE PROTEINS ISOFORMS Kac~mi, F. M o n d o n , T. Fournier Baudelocque, Paris, France.
IN and
PLACENTAL F. F e r r Y .
VESSELS. INSERM
F. U
Cavaill6, A. 361, Maternit~
Vascular resistance is known to be higher in placental villosities than in umbilical arteries (Thomas and Tulenko 1979). The contractile apparatus of umbilical and chorionic arteries and veins 9 as w e l l as of stem villi vessels (SVV), was studied in order to check if either a gradient of myosin or actin, or differences in their isoforms could be involved in m o d u l a t i n g the blood pressure in these different vessels. Mono and two dimensional electophoresis gel systems were used to q u a n t i f y and identify actin and myosin isoforms in e a c h type of v e s s e l s obtained by microdissection of human term placentae. In vascular smooth muscle, the actomyosin quantity (33,8 • 16,5 pg/mg tissu) was found to be high and identical at all the placental levels, with an high ratio (8.8 • 2.4) of actin/myosin. Three isotypes of myosin heavy chains (MHC) were detected i n all the vessel types, with a predominance of the smooth muscle (SM) types (SMI and SM2) in umbilical and chorionic vessels whereas the nonmuscle (NM) type was maJoritary in SVV. A gradient of SMI was found, diminishing from umbilical vessels to SVV, the inverse being found for
the
NM
isoform.
Three
9 ~ NM and y umbilical and
(SM+NM). chorionic
in
actin
SVV.
a
SM
was
isoforms
of
Here again, the vessels whereas the
predominant
actin SM the form
were
also
isoforms NM form in
detected:
~ SM
predomined in was majoritary
arteries,
whereas
a
and y actin were equivalent in veins. One can speculate that these differences in contractile protein isoforms distribution at different levels of placental vessels may contribute to establish the gradient of the blood pressure, via differences in actomyosin activity. This work was supported b y G E R P and INSERM.