Machiko Suzuki

Fujita Health University, Toyohashi, Aichi-ken, Japan

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Publications (11)21.81 Total impact

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    Article: Comparative gene expression profiling of placentas from patients with severe pre-eclampsia and unexplained fetal growth restriction.
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    ABSTRACT: It has been well documented that pre-eclampsia and unexplained fetal growth restriction (FGR) have a common etiological background, but little is known about their linkage at the molecular level. The aim of this study was to further investigate the mechanisms underlying pre-eclampsia and unexplained FGR. We analyzed differentially expressed genes in placental tissue from severe pre-eclamptic pregnancies (n = 8) and normotensive pregnancies with or (n = 8) without FGR (n = 8) using a microarray method. A subset of the FGR samples showed a high correlation coefficient overall in the microarray data from the pre-eclampsia samples. Many genes that are known to be up-regulated in pre-eclampsia are also up-regulated in FGR, including the anti-angiogenic factors, FLT1 and ENG, believed to be associated with the onset of maternal symptoms of pre-eclampsia. A total of 62 genes were found to be differentially expressed in both disorders. However, gene set enrichment analysis for these differentially expressed genes further revealed higher expression of TP53-downstream genes in pre-eclampsia compared with FGR. TP53-downstream apoptosis-related genes, such as BCL6 and BAX, were found to be significantly more up-regulated in pre-eclampsia than in FGR, although the caspases are expressed at equivalent levels. Our current data indicate a common pathophysiology for FGR and pre-eclampsia, leading to an up-regulation of placental anti-angiogenic factors. However, our findings also suggest that it may possibly be the excretion of these factors into the maternal circulation through the TP53-mediated early-stage apoptosis of trophoblasts that leads to the maternal symptoms of pre-eclampsia.
    Reproductive Biology and Endocrinology 08/2011; 9:107. · 2.05 Impact Factor
  • Article: Impact of indoleamine 2,3-dioxygenase on the antioxidant system in the placentas of severely pre-eclamptic patients.
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    ABSTRACT: Indoleamine 2,3-dioxygenase (IDO) is the rate limiting enzyme of the kynurenine pathway that degrades L-tryptophan, but a wider range of functions have now been proposed for this enzyme, including antioxidant activity. Our previous study revealed that reduced IDO expression in the placenta induces defective feto-maternal immuno-tolerance leading to the onset of pre-eclampsia. In our present study, we assessed the effects of low placental IDO activity as an antioxidant. The placental levels of 8-hydroxy-2'-deoxy-guanosine (8-OHdG), a maker for oxidative damage to DNA, were significantly higher in pre-eclamptic than normotensive pregnancies (P<0.05). Immunohistochemical signals of 8-OHdG were detected mainly in syncytiotrophoblasts and vascular endothelial cells, and co-localized with those for IDO. Furthermore, a significant inverse correlation was found between the IDO activity and 8-OhdG levels. These results show that oxidative stress is associated with decreased IDO activity in the pre-eclamptic placenta and suggest an impact of low IDO activity other than immune modulation in promoting the onset of this disorder.
    Systems biology in reproductive medicine 07/2011; 57(4):174-8. · 0.80 Impact Factor
  • Article: Polymorphisms in the annexin A5 gene promoter in Japanese women with recurrent pregnancy loss.
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    ABSTRACT: Recent findings have raised the possibility that polymorphisms within the annexin A5 gene (ANXA5) promoter contribute to the etiology of recurrent pregnancy loss (RPL). In our present study, 243 Japanese women who had suffered more than three fetal losses and a group of 119 fertile controls were genotyped for four ANXA5 gene promoter single-nucleotide polymorphisms (SNPs; SNP1-4: g.-467G >A, g.-448A>C, g.-422T>C, g.-373G>A) previously reported to be associated with this disorder. An additional two SNPs located within the 5'-untranslated region of the ANXA5 (SNP5 and 6: g.-302T>G, g.-1C>T) were also evaluated. Our case--control study revealed that the minor allele was significantly more frequent in the RPL group than controls for all six of these SNPs, among which SNP5 showed the highest significance (P= 0.002). As with the M2 haplotype for SNP1-4 (A-C-C-A) for a western population in previous reports, a haplotype comprising all of the minor alleles for SNP1-6 (A-C-C-A-G-T), the third major haplotype in the Japanese population, showed a significantly higher frequency in our current RPL subjects than in controls (P= 0.025). In addition, the second major haplotype (G-A-T-G-G-C) was found to confer a significant risk of RPL (P= 0.036), implicating SNP5 as a major risk determinant for this disease. Our present findings support the hypothesis that genomic variations within the ANXA5 gene upstream region impact upon the disease susceptibility to RPL. Our data indicate that SNP5 is a novel risk factor for this disease in the Japanese population.
    Molecular Human Reproduction 02/2011; 17(7):447-52. · 3.85 Impact Factor
  • Article: Genetic variation in the indoleamine 2,3-dioxygenase gene in pre-eclampsia.
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    ABSTRACT: To investigate the contribution of genomic variations in the indoleamine 2,3-dioxygenase (IDO) gene to the onset of pre-eclampsia. We examined sequence variations in the IDO1 gene using placental genomic DNA from 35 pre-eclamptic patients and 32 normotensive pregnant women. A case-control study revealed that none of the common variants influences the risk of disease. Sequencing of each IDO1 exon in diseased subjects revealed rare variants. This variation, c.-147_150delGAAA, was located within the 5'-untranslated region of the IDO1 gene, and its homozygote was identified only in pre-eclamptic subjects. However, despite the low levels of IDO expression and enzyme activity in the c.-147_150delGAAA homozygote, reporter assays indicated that this variation does not affect gene expression. Our findings indicate that genetic alteration of fetal IDO gene does not appear to be a primary cause of pre-eclampsia.
    American Journal Of Reproductive Immunology 02/2010; 64(1):68-76. · 2.17 Impact Factor
  • Article: CD9 gene variations are not associated with female infertility in humans.
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    ABSTRACT: To determine whether genetic alterations in the CD9 gene are associated with female infertility in humans. We sequenced the entire coding region of this gene in 86 Japanese women with unexplained infertility and further conducted a case-control study of six tagging single nucleotide polymorphisms (SNPs) in this gene using an additional 164 samples obtained from a fertile control group. No disease-causing mutation in the CD9 gene was evident in these samples and no significant association between the tagging SNPs and the studied cohort was identified. Our findings do not support the hypothesis that genetic alterations of the CD9 gene cause female infertility in humans.
    Gynecologic and Obstetric Investigation 12/2009; 69(2):116-21. · 1.28 Impact Factor
  • Article: Analysis of nitric oxide metabolism as a placental or maternal factor underlying the etiology of pre-eclampsia.
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    ABSTRACT: Defective nitric oxide (NO)-mediated vasodilation is widely regarded as an underlying cause of hypertension in pre-eclampsia, although there are also arguments against this hypothesis. We examined both the mRNA levels and the presence of a Glu298Asp substitution in the NO synthase (NOS) gene, as well as the NO metabolite concentration, in placentas and maternal sera from women with pre-eclampsia and in normotensive pregnant controls (25-40 vs. 24-41 weeks of gestation). Pre-eclamptic and control placentas did not show any significant differences in their NO metabolite levels or their NOS expression levels as measured by quantitative RT-PCR. In addition, we did not find any association between pre-eclampsia and the occurrence of the Glu298Asp amino acid substitution in the NOS gene. In contrast, high maternal circulating NO metabolites were evident in severe pre-eclampsia (p < 0.0001). Although a positive correlation between circulating NO metabolites and blood pressure was not observed, uterine artery resistance measured by ultrasound was found to positively correlate with the maternal NO levels. Our current data suggest that an altered placental NOS pathway is unlikely to be the primary cause of pre-eclampsia and that the activation of this pathway is possibly in response to maternal symptoms.
    Gynecologic and Obstetric Investigation 09/2009; 68(4):239-47. · 1.28 Impact Factor
  • Article: Establishment and characterization of a human uterine endometrial undifferentiated carcinoma cell line, TMG‐L
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    ABSTRACT: Abstract A new cell line of human uterine endometrial undifferentiated carcinoma, designated as TMG-L, was established from the metastatic lymph node of 56-year-old patient TMG-L cells have been cultured with Ham's F-12 medium supplemented with 10% FCS and grew as a loosely adherent monolayer with polygonal or spindle-shaped cells exhibiting poor cell-cell contact and piled up against each other, showing a tendency to grow as floating cells. The doubling time of this cell line was about 48 hours, and chromosomal analysis revealed aneuploidy at passage 25. The cells formed tumors in SCID mouse, the histology of which was similar to that of undifferentiated carcinoma component of primary tumor. TMG-L cells showed the loss of expression and membranous localization of either E-cadherin or - catenin, implied corresponding loss of their adhesive function. And this dysfunction implicated the biological aggressive behavior of uterine endometrial undifferentiated carcinoma. This cell line appears to provide a useful system for studying uterine undifferentiated carcinoma in vivo and in vitro.
    Human Cell 10/2008; 16(1):31 - 38. · 1.27 Impact Factor
  • Article: Increased levels of pregnancy-associated plasma protein-A2 in the serum of pre-eclamptic patients.
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    ABSTRACT: Pregnancy-associated plasma protein-A and -A2 (PAPP-A and -A2) are proteases that cleave insulin-like growth factor-binding proteins (IGFBPs), resulting in local activation of IGF signaling pathways. Here, we examined PAPP-A and -A2 mRNA and protein levels in placenta and maternal sera from women with pre-eclampsia and compared them with samples from uncomplicated pregnancy. PAPP-A2 but not PAPP-A mRNA and protein were elevated in pre-eclamptic placenta (P < 0.01). PAPP-A2 is normally produced in placental syncytiotrophoblast cells and maternal decidua. PAPP-A2 in syncytiotrophoblast cells was dramatically increased in pre-eclampsia. Maternal serum concentrations of PAPP-A2 but not PAPP-A were also significantly elevated in pre-eclampsia as compared with uncomplicated pregnancy. mRNA levels of IGFBP5, a specific substrate for PAPP-A2 protease activity, were also significantly increased, suggesting a potential role for IGFBP5 in fetal and placental growth suppression during pre-eclampsia. However, IGFBP5 protein levels were not increased in placenta from pre-eclampsia, possibly due to cleavage by up-regulated PAPP-A2. These data might imply that PAPP-A2 may be up-regulated in pre-eclamptic pregnancy to compensate for IGFBP5-mediated suppression of the IGF pathway, although final birthweights are still low in pre-eclamptic pregnancy.
    Molecular Human Reproduction 09/2008; 14(10):595-602. · 3.85 Impact Factor
  • Article: Mouse model for allogeneic immune reaction against fetus recapitulates human pre-eclampsia.
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    ABSTRACT: We have previously demonstrated that mRNA expression and enzyme activity levels of placental indoleamine 2,3-dioxygenase (IDO), which degrades L-tryptophan and blocks the proliferation of T cells, are significantly low in patients with severe pre-eclampsia. From this observation, we hypothesized that induction of maternal allogeneic immune reaction by reduced IDO activity is one of the causes of pre-eclampsia. To examine this hypothesis, we administered an IDO inhibitor to pregnant female mice carrying allogeneic concepti. Since administration of an IDO inhibitor to pregnant mice starting at E4.5 is already reported to cause allogeneic fetal rejection, we modified the regimen and started the administration at E6.5 when the fetus and placenta have already been established. Pregnant mice treated with an IDO inhibitor developed high blood pressure and proteinuria in addition to local circulation impairment in the placenta, which is analogous to the lesions that are characteristic of human pre-eclampsia. In contrast, pregnant mice carrying syngeneic concepti did not manifest such symptoms. Our findings reveal a pivotal role for IDO activity in the etiology of pre-eclampsia. These data also lend support to the current hypothesis that pre-eclampsia is one of the possible manifestations of a maternal immunological reaction against an allogeneic fetus.
    Journal of Obstetrics and Gynaecology Research 03/2008; 34(1):1-6. · 0.94 Impact Factor
  • Article: The etiological role of allogeneic fetal rejection in pre-eclampsia.
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    ABSTRACT: It has been demonstrated that allogeneic fetal rejection in normal pregnancy is prevented by placental indoleamine 2,3-dioxygenase (IDO). Further, an immunological etiology has been implicated in pre-eclampsia. We examined the differences in placental IDO activity between normal and pre-eclamptic pregnancies. IDO mRNA expression and enzyme activity levels in the placenta were low in patients with severe pre-eclampsia. The enzyme activity also inversely correlates with the blood pressure of the patients. In the placentas from severe pre-eclampsia, IDO immunoreactivity was low, whereas regional T-cell infiltration was observed reciprocally proportional to the IDO activity. Our findings implicate a potential role for IDO activity and a maternal immunological reaction against an allogeneic fetus in the etiology of pre-eclampsia.
    American journal of reproductive immunology (New York, N.Y.: 1989) 08/2007; 58(1):11-20. · 3.05 Impact Factor
  • Article: Establishment and characterization of a human uterine endometrial undifferentiated carcinoma cell line, TMG-L.
    [show abstract] [hide abstract]
    ABSTRACT: A new cell line of human uterine endometrial undifferentiated carcinoma, designated as TMG-L, was established from the metastatic lymph node of 56-year-old patient TMG-L cells have been cultured with Ham's F-12 medium supplemented with 10% FCS and grew as a loosely adherent monolayer with polygonal or spindle-shaped cells exhibiting poor cell-cell contact and piled up against each other, showing a tendency to grow as floating cells. The doubling time of this cell line was about 48 hours, and chromosomal analysis revealed aneuploidy at passage 25. The cells formed tumors in SCID mouse, the histology of which was similar to that of undifferentiated carcinoma component of primary tumor. TMG-L cells showed the loss of expression and membranous localization of either E-cadherin or alpha-catenin, implied corresponding loss of their adhesive function. And this dysfunction implicated the biological aggressive behavior of uterine endometrial undifferentiated carcinoma. This cell line appears to provide a useful system for studying uterine undifferentiated carcinoma in vivo and in vitro.
    Human Cell 04/2003; 16(1):31-8. · 1.27 Impact Factor