<p>CYP27A1 and CYP7B1 are widely expressed in various human tissues and are two key enzymes involved in the pathways for conversion of cholesterol to bile acids. Also, CYP27A1 is involved in bioactivation of vitamin D3 and CYP7B1 plays a role in 7alpha-hydroxylation of dehydroepiandrosterone and other steroids. Both enzymes have been reported to be relevant to prostate cell proliferation. The current study examines the hormonal regulation of CYP27A1 and CYP7B1.</p><p>CYP7B1 was shown to be regulated by estrogens and androgens in human embryonic kidney HEK293 and prostate cancer LNCaP cells. Quantitation of CYP7B1 mRNA in adult and fetal human tissues showed markedly higher CYP7B1 mRNA levels in fetal tissues compared with the corresponding adult ones, except in the liver. This indicates a tissue-specific, developmental regulation of CYP7B1 and suggests an important function for this enzyme in fetal life. CYP7B1 regulation by estrogens may be of importance in fetal development and in other processes where CYP7B1 is involved, including cholesterol homeostasis, cellular proliferation, and CNS function. The regulation of CYP7B1 by sex hormones also suggests an important role for CYP7B1 in balancing prostate hormone levels in human cells. </p><p>Results show that CYP27A1 can be regulated by dexamethasone, growth hormone, IGF-1, PMA, estrogens and androgens in liver-derived HepG2 cells. Dexamethasone, growth hormone and IGF-1 stimulated the promoter and endogenous activity of CYP27A1, whereas thyroid hormones and PMA inhibited CYP27A1. The regulatory effects of estrogens and androgens are different depending on the cell types. Thus, the results imply that human CYP27A1 gene is a target for estrogens and androgens, and the expression of CYP27A1 may be affected by endogenous sex hormones and pharmacological compounds with estrogenic or androgenic effects. </p><p>The mechanism for the dexamethasone-induced effect on the human CYP27A1 promoter was examined. A GRE was identified important for GR-mediated regulation of CYP27A1 transcriptional activity. </p>

CYP27A1 and CYP7B1 are widely expressed in various human tissues and are two key enzymes involved in the pathways for conversion of cholesterol to bile acids. Also, CYP27A1 is involved in bioactivation of vitamin D3 and CYP7B1 plays a role in 7alpha-hydroxylation of dehydroepiandrosterone and other steroids. Both enzymes have been reported to be relevant to prostate cell proliferation. The current study examines the hormonal regulation of CYP27A1 and CYP7B1. CYP7B1 was shown to be regulated by estrogens and androgens in human embryonic kidney HEK293 and prostate cancer LNCaP cells. Quantitation of CYP7B1 mRNA in adult and fetal human tissues showed markedly higher CYP7B1 mRNA levels in fetal tissues compared with the corresponding adult ones, except in the liver. This indicates a tissue-specific, developmental regulation of CYP7B1 and suggests an important function for this enzyme in fetal life. CYP7B1 regulation by estrogens may be of importance in fetal development and in other processes where CYP7B1 is involved, including cholesterol homeostasis, cellular proliferation, and CNS function. The regulation of CYP7B1 by sex hormones also suggests an important role for CYP7B1 in balancing prostate hormone levels in human cells. Results show that CYP27A1 can be regulated by dexamethasone, growth hormone, IGF-1, PMA, estrogens and androgens in liver-derived HepG2 cells. Dexamethasone, growth hormone and IGF-1 stimulated the promoter and endogenous activity of CYP27A1, whereas thyroid hormones and PMA inhibited CYP27A1. The regulatory effects of estrogens and androgens are different depending on the cell types. Thus, the results imply that human CYP27A1 gene is a target for estrogens and androgens, and the expression of CYP27A1 may be affected by endogenous sex hormones and pharmacological compounds with estrogenic or androgenic effects. The mechanism for the dexamethasone-induced effect on the human CYP27A1 promoter was examined. A GRE was identified important for GR-mediated regulation of CYP27A1 transcriptional activity.

Maternal exposure to viral and bacterial infection during pregnancy is associated with fetal dysmorphology and neurodevelopmental disorders including schizophrenia, cerebral palsy, autism and mental retardation. Previous studies in our laboratory using an established mouse model of endotoxin-induced fetal dysmorphology have led to the hypothesis that birth defects caused by infections during pregnancy are the result of fetal zinc deficiency resulting from the induction of a zinc-binding protein, metallothionein (MT) in the maternal liver as part of the maternal inflammatory response. Thus, we predicted that zinc deficiency would exacerbate the negative fetal outcomes caused by bacterial endotoxin lipopolysaccharide (LPS) and that zinc supplementation would protect against LPS-mediated teratogenicity. This premise was investigated herein and was extended to investigate underlying molecular mechanism, including the identification of markers of neurodevelopmental damage following LPS administration in early and late pregnancy, and to determine the influence of zinc treatment on any changes in expression of these markers. In Chapter 2 it was demonstrated that prenatal exposure to LPS on gestational day (GD) 8 resulted in the development of physical birth defects including exencephaly, microcephaly, cleft lip and or palate, and micrognathia in GD 18 fetuses. Dietary zinc supplementation throughout pregnancy was found to prevent the LPS-related abnormalities. Furthermore, low dietary zinc and LPS exposure were found to be synergistic on teratogenicity. In addition, an inverse linear relationship was observed between the concentration of zinc in the diet and teratogenicity with a reduction in the incidence of birth defects observed with increasing concentration of dietary zinc, a finding suggesting that even small increments of zinc above normal dietary intake are likely to have a beneficial impact on teratogenicity. Maternal infection during late pregnancy has also been linked with prenatal brain damage. A major causal link underpinning this relationship is thought to be the cytokines released following a maternal inflammatory response to infection. In Chapter 3, the presence of cytokines released in response to LPS given on GD 16 was demonstrated by an increased number of tumour necrosis factor-alpha (TNF-!)-reactive cells and astrogliosis accompanied by extensive apoptotic cell death in GD 18 fetal brain. Recently our laboratory has reported that dietary zinc supplementation throughout pregnancy, prevented impairments in object recognition memory in offspring from dams exposed to prenatal LPS on GD 8. The question arises as to whether zinc is protective against LPS-exposure in late pregnancy. In Chapter 3, it is further demonstrated that LPS-induced brain injury was prevented by concurrent zinc treatment at the time of LPS exposure. In Chapter 4, the expression of activity-dependent neuroprotective protein (ADNP) mRNA was identified as a marker of changes occurring in the fetus as a result of LPS exposure in early pregnancy. ADNP has been found to be essential for organogenesis and is a sensitive indicator of brain injury. Here it was demonstrated that LPS caused a rapid increase in embryonic ADNP expression, which was highly significant 24 hours after exposure. Whether the elevation in ADNP expression is in response to inflammatory damage or is induced by cytokines released by the maternal inflammatory response is not clear. However, a major finding of the study is that concomitant zinc treatment prevented the LPS-induced increase in ADNP activity. The mechanism of protection by zinc is presumed to be centred on preventing the fall in plasma zinc and associated fetal zinc deficiency caused by LPS induction of MT, but may also include MT-independent actions of zinc including prevention of apoptosis and oxidative damage, or enhance tissue repair processes. Taken together the findings in this thesis support earlier evidence that maternal MTmediated transient fetal zinc deficiency in early pregnancy underpins LPS-induced teratogenicity. This is the first study to demonstrate that this mechanism may also apply to LPS-induced neurodevelopmental damage in early and late pregnancy. However, further studies are warranted to discriminate between the influence of MT and that of other inflammatory reactants (e.g. cytokines) on LPS-mediated damage late in pregnancy. The major finding of the thesis is that zinc treatment (either given subcutaneously with LPS or as dietary zinc supplementation throughout pregnancy) prevents the negative fetal outcomes including neurodevelopmental damage caused by prenatal exposure to LPS. This finding highlights the importance of zinc nutrition in pregnancy and the benefits that might be gained as a potential prophylactic treatment to minimise fetal damage caused by infections during pregnancy. / Thesis (Ph.D.) -- University of Adelaide, School of Molecular and Biomedical Science, 2009

Maternal exposure to viral and bacterial infection during pregnancy is associated with fetal dysmorphology and neurodevelopmental disorders including schizophrenia, cerebral palsy, autism and mental retardation. Previous studies in our laboratory using an established mouse model of endotoxin-induced fetal dysmorphology have led to the hypothesis that birth defects caused by infections during pregnancy are the result of fetal zinc deficiency resulting from the induction of a zinc-binding protein, metallothionein (MT) in the maternal liver as part of the maternal inflammatory response. Thus, we predicted that zinc deficiency would exacerbate the negative fetal outcomes caused by bacterial endotoxin lipopolysaccharide (LPS) and that zinc supplementation would protect against LPS-mediated teratogenicity. This premise was investigated herein and was extended to investigate underlying molecular mechanism, including the identification of markers of neurodevelopmental damage following LPS administration in early and late pregnancy, and to determine the influence of zinc treatment on any changes in expression of these markers. In Chapter 2 it was demonstrated that prenatal exposure to LPS on gestational day (GD) 8 resulted in the development of physical birth defects including exencephaly, microcephaly, cleft lip and or palate, and micrognathia in GD 18 fetuses. Dietary zinc supplementation throughout pregnancy was found to prevent the LPS-related abnormalities. Furthermore, low dietary zinc and LPS exposure were found to be synergistic on teratogenicity. In addition, an inverse linear relationship was observed between the concentration of zinc in the diet and teratogenicity with a reduction in the incidence of birth defects observed with increasing concentration of dietary zinc, a finding suggesting that even small increments of zinc above normal dietary intake are likely to have a beneficial impact on teratogenicity. Maternal infection during late pregnancy has also been linked with prenatal brain damage. A major causal link underpinning this relationship is thought to be the cytokines released following a maternal inflammatory response to infection. In Chapter 3, the presence of cytokines released in response to LPS given on GD 16 was demonstrated by an increased number of tumour necrosis factor-alpha (TNF-!)-reactive cells and astrogliosis accompanied by extensive apoptotic cell death in GD 18 fetal brain. Recently our laboratory has reported that dietary zinc supplementation throughout pregnancy, prevented impairments in object recognition memory in offspring from dams exposed to prenatal LPS on GD 8. The question arises as to whether zinc is protective against LPS-exposure in late pregnancy. In Chapter 3, it is further demonstrated that LPS-induced brain injury was prevented by concurrent zinc treatment at the time of LPS exposure. In Chapter 4, the expression of activity-dependent neuroprotective protein (ADNP) mRNA was identified as a marker of changes occurring in the fetus as a result of LPS exposure in early pregnancy. ADNP has been found to be essential for organogenesis and is a sensitive indicator of brain injury. Here it was demonstrated that LPS caused a rapid increase in embryonic ADNP expression, which was highly significant 24 hours after exposure. Whether the elevation in ADNP expression is in response to inflammatory damage or is induced by cytokines released by the maternal inflammatory response is not clear. However, a major finding of the study is that concomitant zinc treatment prevented the LPS-induced increase in ADNP activity. The mechanism of protection by zinc is presumed to be centred on preventing the fall in plasma zinc and associated fetal zinc deficiency caused by LPS induction of MT, but may also include MT-independent actions of zinc including prevention of apoptosis and oxidative damage, or enhance tissue repair processes. Taken together the findings in this thesis support earlier evidence that maternal MTmediated transient fetal zinc deficiency in early pregnancy underpins LPS-induced teratogenicity. This is the first study to demonstrate that this mechanism may also apply to LPS-induced neurodevelopmental damage in early and late pregnancy. However, further studies are warranted to discriminate between the influence of MT and that of other inflammatory reactants (e.g. cytokines) on LPS-mediated damage late in pregnancy. The major finding of the thesis is that zinc treatment (either given subcutaneously with LPS or as dietary zinc supplementation throughout pregnancy) prevents the negative fetal outcomes including neurodevelopmental damage caused by prenatal exposure to LPS. This finding highlights the importance of zinc nutrition in pregnancy and the benefits that might be gained as a potential prophylactic treatment to minimise fetal damage caused by infections during pregnancy. / Thesis (Ph.D.) -- University of Adelaide, School of Molecular and Biomedical Science, 2009

Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / Härtill 6 uppsatser.

Diss. (sammanfattning) Uppsala : Univ., 2004. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 6 uppsatser.

Thesis (M.S.)--University of Michigan, 1993.

Thesis (M.S.)--University of Michigan, 1993.

Submitted by (lucia.rodrigues@ufrpe.br) on 2016-06-10T13:14:18Z No. of bitstreams: 1 Welma Emidio da Silva.pdf: 1500896 bytes, checksum: 7ff17715c3c5e19b309e27006eee6e14 (MD5) / Made available in DSpace on 2016-06-10T13:14:18Z (GMT). No. of bitstreams: 1 Welma Emidio da Silva.pdf: 1500896 bytes, checksum: 7ff17715c3c5e19b309e27006eee6e14 (MD5) Previous issue date: 2012-02-16 / Several authors have reported that metronidazole crosses the placental barrier and enters the fetal circulation and is still excreted in breast milk. Thus, not recommend the use of this drug in pregnant women and also the breastfeeding suspension for 12-24 hours after administration. However, some investigators report lack of evidence that the use of metronidazole is associated with increased risk teratogenic when administered during pregnancy is therefore unnecessary waiting for the termination of pregnancy for treatment with this drug. Thus, this study aimed to analyze the effect of administration of metronidazole during pregnancy on placental and fetal development of albino rats. 30 albino rats were used, which were divided into two groups. GROUP I - pregnant rats treated with placebo and GRUPOII - pregnant rats treated with metronidazole. The metronidazole was administered daily by gavage at a dose of 130 mg / kg for 7, 14 and 21 days of gestation. The results showed that the treated group a significant reduction in the number of deployment sites, the total area of the placental disc and the constituents of the layers of the labyrinth and trofospôngio. The histochemical analysis revealed no significant changes in the content of collagen and elastic fibers and reticular. The test showed TUNEL apoptotic activity at the site of implantation and placental development 14 days regardless of treatment. We did not observe any evidence of malformation in the head, trunk and limbs of neonates. However, a significant reduction in weight and number of neonates in the group treated with metronidazole compared to control. Thus, we conclude that metronidazole in pregnant rats administered orally at a dosage of 130 mg / kg, in two thirds of early pregnancy interferes with the interaction blastocyst endometrium, in placental and fetal development, suggesting that this drug should be avoided in the early stages of pregnancy. / Vários autores relatam que o metronidazol atravessa a barreira placentária e penetra na circulação fetal, sendo ainda excretado no leite materno. Desta forma, não recomendam o uso dessa droga em mulheres gestantes e também a suspensão do aleitamento materno por 12 a 24 horas após a administração do mesmo. Entretanto alguns pesquisadores relatam faltar evidências de que o uso do metronidazol está associado com o aumento de riscos teratogênicos quando administrado durante a gestação sendo, portanto, desnecessário a espera do termino da gestação para o tratamento com essa droga. Assim, a presente pesquisa teve como objetivos analisar o efeito da administração do metronidazol durante a prenhez, sobre o desenvolvimento placentário e fetal de ratas albinas. Foram utilizadas 30 ratas albinas, que foram divididas em dois grupos. GRUPO I – ratas prenhas tratadas com placebo e GRUPOII – ratas prenhas tratadas com metronidazol. O metronidazol foi administrado por gavagem na dosagem diária de 130 mg/kg durante 7, 14 e 21 dias de gestação. Os resultados mostraram que no grupo tratado houve redução significativa do número de sítios de implantação, da área total do disco placentário e nos elementos constituintes das camadas do labirinto e trofospôngio. A análise histoquímica não revelou alterações significativas no teor de fibras colágenas, elásticas e reticulares. O teste de TUNEL mostrou atividade apoptótica nos sítios de implantação e placentas com 14 dias de desenvolvimento independente do tratamento. Não foram observados nenhum indício de malformação na cabeça, tronco e membros dos neonatos. No entanto, houve uma redução significativa no número e peso dos neonatos no grupo tratado com o metronidazol em relação ao controle. Assim, concluímos que o metronidazol administrado em ratas prenhes, por via oral, na dosagem de 130 mg/Kg, nos dois terços iniciais da gestação interfere na interação blastocisto endométrio, no desenvolvimento placentário e fetal, sugerindo que o uso desse medicamento deve ser evitado nas fases iniciais da gestação.