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Angiogenesis and the placental environment
Citations from the literature/International
Journal of Gynecology & Obstetrics 52 (19%) 217-227
quencesfor the specific locus surrounding the four base pair insertion mutation on exon I I of-hexosaminidase A-Tay-Sachs disease,the DcltaF508 mutation of cystic fibrosis, and the sexdetermining region on the Y chromosome. Reamplification polymerase chain reaction with standard polymerase chain reaction and primer extension preamplilication was performed in deoxyribonucleic acid preparations after previous polymerasechain reaction amplification attempts had resulted in failure of amplification. Results: The amplification efficiency of TaySachsdisease,51% (97/187), was significantly lower than that for cystic fibrosis, 85% (87/107), and for the sex-detetmining region on the Y chromosome, 85% (77/90). Tay-Sachs disease polymerase chain reaction amplification occurred in 51% of one-cell lymphoblasts, 89% of two-cell lymphoblasts, and 94% of sampleswhen more than two cells were processedtogether. When previous amplification failure had occurred, standard Tay-Sachsdiseasepolymerase chain reaction resulted in an amplification efficiency of 16% (three of l9), whereas primer extension preamplilication polymerase chain reaction for Tay-Sachsdiseaseresulted in amplification of 52% (31/59)lymphoblasts and 54% (13/24) of polyspermic human blastomeres. Four of six human blastomeres in which amplification failure occurred in a Tay-Sachs diseasepreimplantation genetic diagnosis cycle amplified by primer extension preamplification polymerase chain reaction, which increased the diagnostic information obtained from four to six of the seven embryos on which biopsy was performed. Conclusions: We suggest that practical approaches for consideration within a clinical preimplantation genetic diagnosis program to limit the net effect of amplification failure (i.e., reduced embryo transfer number) include increasing the deoxyribonucleic acid content in the polymerasechain reaction tube by using more than one blastomere and by using primer extension preamplification when the initial attempt at amplilication fails. Aogiogemesis and the placental environment
Wheeler T.; Elcock CL.; Anthony F.W. PLACENTA 1995 l6/3 (289-296) Rapid growth and vascularization of the human placenta are characteristic of early pregnancy, and are accomplished in an unusually, hypoxic environment. Stimulation of placental growth through hypoxin-induced angiogenesis may therefore be of particular importance. We have previously found that several varieties of vascular endothelial growth factor (VEGF) mRNA, including VEGFl65, are present in cultured placental libroblasts. We hypothesized that hypoxin would increase the transcription and translation of VEGF by these cells and provide one mechanismlinking placental development with its environment. Placental libroblasts were grown in aerobic or anaerobic atmospheric conditions for 72 h. By 24 h the oxygen tension of the anaerobic culture media was significantly less than that of the aerobic cultures. RNA was extracted from the cells at 24, 48 and 72 h. Following reverse transcription polymerase chain reaction (RT-PCR) stronger signals for VEGF were always found in the anaerobic cultures and this was confirmed by competitive PCR. mRNA for VEGFl65, was representedmost strongly but the anaerobic cultures also show-
223
ed clear, mRNA for VEGFIZI, VEGFl89 and VEGF206. The VEGF protein was also measuredin the aerobic and anaerobic culture medium. By 72 h the average concentration of VEGF was significantly higher (P = 0.01) in the anaerobic culture medium. VEGF production is one mechanismthrough which oxygen supply may influence placental development. Examples of this may include the compensatory placental hypertrophy associatedwith maternal anemia and with reproduction at high altitude. placental Immuwbistocbemical hcalizatlon of pqnaocy-felated protein 4 in buman placenta, umbilical cord sod adult human female genital tksues
Gocze P.M.; Jozsa R.; Szabo D.G.; Bohn H.; Freeman D.A. PLACENTA 1995 l6/3 (309-316) Placental protein 4 (PP4) is a soluble placental tissue protein which was isolated from human placenta. The aim of the present study was to demonstrate the localization of cells containing PP4 In human placenta and in various female genital tissues under normal conditions. PP4 immunoreactive structures mere demonstrated by using the peroxidase-antiperoxidase immunohistochemical technique. The samples were obtained from normal human placenta, umbilical cord, uterine cervix, endometrium, ovary and vulva. The most differentiated trophoblastic cells, the syncytiotrophoblasts, as well as the intermediate trophoblast cells contained PP4. PP4 immunoreactivity, was present in umbilical cord as well. Gccasionally, PP4 was detected in normal ovarian, endometrial or vulvar tissuesamples.Cervix and myometrium were free of PP4 immunoreactive material. PP4 staining was cytoplasmic. Our findings indicate that PP4 cannot be considered specific for the placenta since it is present in some human adult tissuesas well. Beta 1 lotegrim in third trimester bumno placentae: No differew tial expression in pathological pregnaocy
Divers M.J.; Bulmer J.N.; Miller D.; Lilford R.J. PLACENTA 1995 l6/3 (245-260) Integrins are a group of cell surface receptors that play important roles in cell-cell and cell-extracellular matrix interactions. The expression of trophoblast cell surface integrin subunits changesduring placental development in normal pregnancy but the functional significance is unknown. The aim of this study was to investigate the expression of I integrins and their extracellular matrix ligands ill human placenta and membranes in normal and pathological pregnancy, using an avidinbiotin-peroxidase technique. Expression of the I integrins was similar in all study groups. Whilst there was someheterogeneity of expression of specific integrin a chains this was not characteristic of defined subject groups, variations occurring within all groups. Two distinct trophoblast subpopulations were demonstrated in the chorion laeve according to differential expression of I integrins. Trophoblast immediately adjacent to maternal decidua, which expressed I rather than 2, also comprised the majority of trophoblast in the basal plate; possessionof the I, 3, 5,6 rather than 2, 3, 5, 6 phenotype may be important in the invasive potential of trophoblast populations. The results obtained in the present study indicate that the
Journal of Gynecology & Obstetrics 52 (19%) 217-227
quencesfor the specific locus surrounding the four base pair insertion mutation on exon I I of-hexosaminidase A-Tay-Sachs disease,the DcltaF508 mutation of cystic fibrosis, and the sexdetermining region on the Y chromosome. Reamplification polymerase chain reaction with standard polymerase chain reaction and primer extension preamplilication was performed in deoxyribonucleic acid preparations after previous polymerasechain reaction amplification attempts had resulted in failure of amplification. Results: The amplification efficiency of TaySachsdisease,51% (97/187), was significantly lower than that for cystic fibrosis, 85% (87/107), and for the sex-detetmining region on the Y chromosome, 85% (77/90). Tay-Sachs disease polymerase chain reaction amplification occurred in 51% of one-cell lymphoblasts, 89% of two-cell lymphoblasts, and 94% of sampleswhen more than two cells were processedtogether. When previous amplification failure had occurred, standard Tay-Sachsdiseasepolymerase chain reaction resulted in an amplification efficiency of 16% (three of l9), whereas primer extension preamplilication polymerase chain reaction for Tay-Sachsdiseaseresulted in amplification of 52% (31/59)lymphoblasts and 54% (13/24) of polyspermic human blastomeres. Four of six human blastomeres in which amplification failure occurred in a Tay-Sachs diseasepreimplantation genetic diagnosis cycle amplified by primer extension preamplification polymerase chain reaction, which increased the diagnostic information obtained from four to six of the seven embryos on which biopsy was performed. Conclusions: We suggest that practical approaches for consideration within a clinical preimplantation genetic diagnosis program to limit the net effect of amplification failure (i.e., reduced embryo transfer number) include increasing the deoxyribonucleic acid content in the polymerasechain reaction tube by using more than one blastomere and by using primer extension preamplification when the initial attempt at amplilication fails. Aogiogemesis and the placental environment
Wheeler T.; Elcock CL.; Anthony F.W. PLACENTA 1995 l6/3 (289-296) Rapid growth and vascularization of the human placenta are characteristic of early pregnancy, and are accomplished in an unusually, hypoxic environment. Stimulation of placental growth through hypoxin-induced angiogenesis may therefore be of particular importance. We have previously found that several varieties of vascular endothelial growth factor (VEGF) mRNA, including VEGFl65, are present in cultured placental libroblasts. We hypothesized that hypoxin would increase the transcription and translation of VEGF by these cells and provide one mechanismlinking placental development with its environment. Placental libroblasts were grown in aerobic or anaerobic atmospheric conditions for 72 h. By 24 h the oxygen tension of the anaerobic culture media was significantly less than that of the aerobic cultures. RNA was extracted from the cells at 24, 48 and 72 h. Following reverse transcription polymerase chain reaction (RT-PCR) stronger signals for VEGF were always found in the anaerobic cultures and this was confirmed by competitive PCR. mRNA for VEGFl65, was representedmost strongly but the anaerobic cultures also show-
223
ed clear, mRNA for VEGFIZI, VEGFl89 and VEGF206. The VEGF protein was also measuredin the aerobic and anaerobic culture medium. By 72 h the average concentration of VEGF was significantly higher (P = 0.01) in the anaerobic culture medium. VEGF production is one mechanismthrough which oxygen supply may influence placental development. Examples of this may include the compensatory placental hypertrophy associatedwith maternal anemia and with reproduction at high altitude. placental Immuwbistocbemical hcalizatlon of pqnaocy-felated protein 4 in buman placenta, umbilical cord sod adult human female genital tksues
Gocze P.M.; Jozsa R.; Szabo D.G.; Bohn H.; Freeman D.A. PLACENTA 1995 l6/3 (309-316) Placental protein 4 (PP4) is a soluble placental tissue protein which was isolated from human placenta. The aim of the present study was to demonstrate the localization of cells containing PP4 In human placenta and in various female genital tissues under normal conditions. PP4 immunoreactive structures mere demonstrated by using the peroxidase-antiperoxidase immunohistochemical technique. The samples were obtained from normal human placenta, umbilical cord, uterine cervix, endometrium, ovary and vulva. The most differentiated trophoblastic cells, the syncytiotrophoblasts, as well as the intermediate trophoblast cells contained PP4. PP4 immunoreactivity, was present in umbilical cord as well. Gccasionally, PP4 was detected in normal ovarian, endometrial or vulvar tissuesamples.Cervix and myometrium were free of PP4 immunoreactive material. PP4 staining was cytoplasmic. Our findings indicate that PP4 cannot be considered specific for the placenta since it is present in some human adult tissuesas well. Beta 1 lotegrim in third trimester bumno placentae: No differew tial expression in pathological pregnaocy
Divers M.J.; Bulmer J.N.; Miller D.; Lilford R.J. PLACENTA 1995 l6/3 (245-260) Integrins are a group of cell surface receptors that play important roles in cell-cell and cell-extracellular matrix interactions. The expression of trophoblast cell surface integrin subunits changesduring placental development in normal pregnancy but the functional significance is unknown. The aim of this study was to investigate the expression of I integrins and their extracellular matrix ligands ill human placenta and membranes in normal and pathological pregnancy, using an avidinbiotin-peroxidase technique. Expression of the I integrins was similar in all study groups. Whilst there was someheterogeneity of expression of specific integrin a chains this was not characteristic of defined subject groups, variations occurring within all groups. Two distinct trophoblast subpopulations were demonstrated in the chorion laeve according to differential expression of I integrins. Trophoblast immediately adjacent to maternal decidua, which expressed I rather than 2, also comprised the majority of trophoblast in the basal plate; possessionof the I, 3, 5,6 rather than 2, 3, 5, 6 phenotype may be important in the invasive potential of trophoblast populations. The results obtained in the present study indicate that the