by Chung Lap Chan. / "March 1999." / Thesis (Ph.D.)--Chinese University of Hong kong, 1999. / Includes bibliographical references (p. 270-307). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Le Gengyun. / Thesis submitted in: December 2002. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 161-182). / Abstracts in English and Chinese. / Abstract --- p.i / Abbreviations --- p.v / Acknowledgements --- p.vii / Publications --- p.viii / Table of Contents --- p.ix / Chapter Chapter 1 --- INTRODUCTION --- p.1 / Chapter 1. --- Vasoconstrictors --- p.1 / Chapter 1.1 --- An overview of vascular smooth muscle contraction --- p.1 / Chapter 1.2 --- Strong and weak vasoconstrictors --- p.5 / Chapter 1.2.1 --- Mechanisms involved in TP receptor vasoconstriction --- p.6 / Chapter 1.2.1.1 --- Brief introduction to the TP receptor --- p.6 / Chapter 1.2.1.2 --- Second messenger systems --- p.6 / Chapter 1.2.1.3 --- G-protein-linked pathways --- p.7 / Chapter 1.2.1.3.1 --- G proteins --- p.7 / Chapter 1.2.1.3.2 --- G-protein-linked TP receptor signal transduction --- p.8 / Chapter 1.2.2 --- Mechanisms involved in α1-adrenoceptor vasoconstriction --- p.8 / Chapter 1.2.2.1 --- Brief introduction to the α1-adrenoceptor --- p.8 / Chapter 1.2.2.2 --- Second messenger systems --- p.9 / Chapter 1.2.2.3 --- G-protein-linked α-adrenoceptor signal transduction --- p.9 / Chapter 1.3 --- Prostanoid EP3 receptor agonists (weak vasoconstrictors) --- p.10 / Chapter 1.3.1 --- Prostanoids --- p.10 / Chapter 1.3.1.1 --- Biochemical characteristics of prostanoids --- p.10 / Chapter 1.3.1.1.1 --- Biosynthesis of prostanoids --- p.10 / Chapter 1.3.1.1.2 --- Metabolism of prostanoids --- p.11 / Chapter 1.3.1.2 --- Prostanoid receptors --- p.13 / Chapter 1.3.1.2.1 --- Structures --- p.13 / Chapter 1.3.1.2.2 --- Current Status of Classification --- p.14 / Chapter 1.3.1.2.3 --- Signal transduction --- p.16 / Chapter 1.3.1.2.4 --- Distribution --- p.18 / Chapter 1.3.1.2.5 --- Physiological functions --- p.18 / Chapter 2. --- Interactions between vasoconstrictors --- p.19 / Chapter 2.1 --- Cross-talk between G-protein-coupled receptors --- p.19 / Chapter 2.1.1 --- Cross-talk between different receptor families --- p.19 / Chapter 2.1.2 --- Cross-talk between subtypes of the same receptor family --- p.21 / Chapter 2.1.3 --- Cross-talk at the effector level --- p.23 / Chapter 2.2 --- Proposed pathways involved in synergistic interactions --- p.24 / Chapter 2.2.1 --- Rho and Rho-associated kinase --- p.24 / Chapter 2.2.1.1 --- Rho family and its identification --- p.24 / Chapter 2.2.1.2 --- Mechanism(s) of Rho contribution in vasoconstriction --- p.25 / Chapter 2.2.1.3 --- Interactions between Rho and other pathways --- p.26 / Chapter 2.2.2 --- Receptor tyrosine kinases --- p.29 / Chapter 2.2.2.1 --- RTK family --- p.29 / Chapter 2.2.2.2 --- Activation of RTKs --- p.29 / Chapter 2.2.2.3 --- Mechanism(s) of RTK contribution in vasoconstriction --- p.30 / Chapter 2.2.2.4 --- Interactions between RTKs and MAPKs --- p.31 / Chapter 2.2.3 --- Mitogen-activated protein kinase --- p.34 / Chapter 2.2.3.1 --- p38 MAPK --- p.35 / Chapter 2.2.3.2 --- JNK MAPK --- p.35 / Chapter 2.2.3.3 --- ERK MAPK --- p.36 / Chapter 2.2.3.4 --- Interactions between MAPK and GPCRs --- p.37 / Chapter Chapter 2 --- FORCE MEASUREMENT SYSTEM --- p.41 / Chapter 1. --- Introduction --- p.41 / Chapter 2. --- Materials --- p.41 / Chapter 2.1 --- Drugs --- p.41 / Chapter 2.2 --- Chemicals --- p.41 / Chapter 2.3 --- Solutions --- p.46 / Chapter 3. --- Methods --- p.46 / Chapter 3.1 --- Isolated smooth muscle preparations and organ bath set-up --- p.46 / Chapter 3.2 --- Data analysis --- p.47 / Chapter Chapter 3 --- VASOCONSTRICTORS AND THEIR INTERACTIONS --- p.48 / Chapter 1. --- Introduction --- p.48 / Chapter 2. --- Materials and Methods --- p.48 / Chapter 2.1 --- Materials --- p.48 / Chapter 2.2 --- Methods --- p.51 / Chapter 2.2.1 --- Isolated tissue preparations --- p.51 / Chapter 2.2.2 --- Experimental protocols --- p.51 / Chapter 2.2.3 --- Statistical analysis --- p.52 / Chapter 3. --- Results --- p.55 / Chapter 3.1 --- Typical vasoconstrictor profiles of agonists --- p.55 / Chapter 3.1.1 --- Sulprostone contraction --- p.55 / Chapter 3.1.2 --- U-46619 contraction --- p.55 / Chapter 3.1.3 --- Phenylephrine contraction --- p.56 / Chapter 3.2 --- Synergistic interactions between sulprostone and strong vasoconstrictors --- p.58 / Chapter 3.2.1 --- Enhancement of U-46619 response by sulprostone --- p.58 / Chapter 3.2.2 --- Enhancement of phenylephrine response by sulprostone --- p.58 / Chapter 3.2.3 --- Enhancement of sulprostone response by phenylephrine --- p.58 / Chapter Chapter 4 --- INVESTIGATION OF PATHWAYS INVOLVED IN EP3 AGONIST- INDUCED VASOCONSTRICTION --- p.64 / Chapter 1. --- Introduction --- p.64 / Chapter 2. --- Materials and methods --- p.65 / Chapter 2.1 --- Materials --- p.65 / Chapter 2.2 --- Methods --- p.65 / Chapter 2.2.1 --- Isolated tissue preparations --- p.65 / Chapter 2.2.2 --- Experimental protocols --- p.65 / Chapter 2.2.3 --- Statistical analysis --- p.69 / Chapter 3. --- Results --- p.70 / Chapter 3.1 --- Effects of tyrosine kinase inhibitors --- p.70 / Chapter 3.2 --- Effects of MAPK inhibitors --- p.82 / Chapter 3.2.1 --- Effects of MAPK inhibitors on U-46619 responses --- p.82 / Chapter 3.2.2 --- Effects of MAPK inhibitors on sulprostone responses --- p.91 / Chapter 3.2.3 --- Effects of MAPK inhibitors on phenylephrine responses --- p.100 / Chapter 3.3 --- Effects of Rho-kinase inhibitors --- p.104 / Chapter Chapter 5 --- TRANSFECTED CELL LINE SYSTEM --- p.111 / Chapter 1. --- Introduction --- p.111 / Chapter 2. --- Materials and methods --- p.114 / Chapter 2.1 --- Materials --- p.114 / Chapter 2.1.1 --- Plasmids and vectors --- p.114 / Chapter 2.1.2 --- Radioactive agents --- p.114 / Chapter 2.1.3 --- Chemicals --- p.114 / Chapter 2.1.4 --- Restriction digest enzymes --- p.115 / Chapter 2.1.5 --- "Culture media, buffers and solutions" --- p.115 / Chapter 2.1.5.1 --- Culture media / Chapter 2.1.5.2 --- Buffers and solutions --- p.115 / Chapter 2.2 --- Methods --- p.116 / Chapter 2.2.1 --- Transfected cell lines --- p.116 / Chapter 2.2.1.1 --- Subcloning of hEP3-1 receptor and hTP receptor cDNA --- p.116 / Chapter 2.2.1.1.1 --- Plasmid recovery / Chapter 2.2.1.1.2 --- Preparation of competent cells --- p.116 / Chapter 2.2.1.1.3 --- Transformation of competent cells --- p.117 / Chapter 2.2.1.1.4 --- Extraction of DNA by QIAGEN Plasmid Mini Kit --- p.117 / Chapter 2.2.1.1.5 --- Restriction enzymes digestion and dephosphorylation --- p.117 / Chapter 2.2.1.1.6 --- DNA recovery and ligation / Chapter 2.2.1.1.7 --- Positive recombinant DNA selection --- p.119 / Chapter 2.2.1.2 --- Cell culture --- p.119 / Chapter 2.2.1.3 --- Transient transfection of CHO cells --- p.121 / Chapter 2.2.1.4 --- Mesurement of adenylate cyclase activity --- p.121 / Chapter 2.2.1.4.1 --- Preparation of columns --- p.121 / Chapter 2.2.1.4.2 --- [3H]-cAMP assays --- p.122 / Chapter 2.2.1.5 --- Measurement of phospholipase C activity --- p.122 / Chapter 2.2.1.5.1 --- Preparation of columns --- p.123 / Chapter 2.2.1.5.2 --- [3H]-inositol phosphate assay --- p.123 / Chapter 2.2.2 --- Data analysis --- p.124 / Chapter 3. --- Results --- p.125 / Chapter 3.1 --- Subcloning of hEP3-1and hTPα receptor cDNA into expression vectors --- p.125 / Chapter 3.2 --- Measurement of cAMP and IP production in transfected CHO cells --- p.133 / Chapter 3.2.1 --- Effect of varying receptor cDNA concentration on agonist-stimulated [3H]-cAMP and [3H]-IP production in transiently transfected CHO cells --- p.133 / Chapter 3.2.2 --- Effect of agonists on intracellular [3H]-IP or [3H]-cAMP productionin CHO cells transfected with hTPα or hEP3-1 --- p.133 / Chapter 3.3 --- Summary --- p.134 / Chapter Chapter 6 --- GENERAL DISCUSSION AND CONCLUSIONS --- p.137 / Chapter 1. --- Vasoconstrictors and their interactions --- p.137 / Chapter 1.1 --- Vasoconstrictors --- p.137 / Chapter 1.2 --- Synergism --- p.138 / Chapter 2. --- Investigation of possible pathways --- p.140 / Chapter 2.1 --- Rho-associated kinase --- p.140 / Chapter 2.2 --- Receptor tyrosine kinase --- p.147 / Chapter 2.3 --- Mitogen-activated protein kinase (MAPK) --- p.151 / Chapter 3. --- Effect of vehicles --- p.155 / Chapter 4. --- Biochemical studies in transfected CHO cells --- p.157 / Chapter 5. --- Conclusions --- p.158 / Appendix I --- p.159 / Buffers and Solutions used in transfected system --- p.159 / Chapter 1. --- Buffers --- p.159 / Chapter 2. --- Solutions --- p.159 / REFERENCES --- p.161

Apesar de inúmeros estudos desenvolvidos no Brasil e no mundo, a utilização das biotecnologias de superovulação (SOV) e transferência de embriões (TE) em bubalinos ainda apresenta resultados inconsistentes, associados à principalmente à baixa taxa de recuperação de embriões. Dessa forma, o objetivo do presente estudo foi avaliar o efeito da utilização de dispositivo de P4 (para promover diminuição da contratilidade do trato genital, Capitulo 1) ou da administração de PGF2&#945; (para promover aumento da atividade da fímbria e da frequência do batimento ciliar, Capítulo 2) durante o período periovulatório na captação dos oócitos pelas fímbrias e no aumento da produção de embriões em búfalas superovuladas. No Experimento 1 (Capítulo 1), doadoras bubalinas foram homogeneamente divididas em dois grupos: controle (G-C; n=8) e tratamento com progesterona (P4) durante o período periovulatório (G-P4; n=8). A emergência da onda de crescimento folicular foi sincronizada com um dispositivo intravaginal de P4 e a administração de 2 mg i.m. de benzoato de em dia aleatório do ciclo estral (Dia 0; D0). A partir do D4, todas as búfalas receberam 200 mg i.m. de FSH duas vezes ao dia, em 8 doses decrescentes. Foram administrados 530&micro;g i.m. de PGF2&#945; no D6 e no D7. A P4 foi removida do G-C no D7 e do G-P4 no D10. No D8, todas as búfalas receberam 25 mg i.m. de pLH. As inseminações foram realizadas 12 e 24 h após o tratamento com pLH. Foram realizadas colheitas de sangue a cada 12h do D7 ao D11 para posterior dosagem de progesterona. As estruturas embrionárias (oócitos/embriões) foram coletadas pelo método não cirúrgico de lavagem uterina seis dias após a segunda IA (D14). Avaliações ultrassonográficas dos ovários foram realizadas no D8 e no D14 para aferir respectivamente as respostas superestimulatória e superovulatória. As variáveis foram analisadas pelo procedimento GLIMMIX do SAS®. As búfalas do G-P4 apresentaram menor taxa de ovulação (13,5±4,9 vs. 71,5±16,1%; P=0,002) e, consequentemente, maior taxa de folículos &ge; 8 mm (87,8±10,6 vs. 34,3±9,8 %; P=0,06) e menor número de CLs no D14 (1,1±0,3 vs. 8,0±2,8; P=0,04) que as búfalas do G-C. O número de estruturas embrionárias (1,9±0,7 vs. 0,0±0,0; P=0,03), de embriões transferíveis (1,6±0,7 vs. 0,0±0,0; P=0,04) e congeláveis (1,6±0,7 vs. 0,0±0,0; P=0,04) foram inferiores para o G-P4. A concentração sérica de progesterona foi maior nos animais do G-P4 (1,87±0,13) que nos do G-C (0,48±0,10; P<0,0001). No Experimento 1 (Capítulo 2), as doadoras foram divididas aleatoriamente em 2 grupos: controle (G-C; n=22) e tratamento com prostaglandina F2&#945; durante o período periovulatório (G-PGF; n=22). Os animais do G-C foram submetidos ao protocolo de superovulação descrito no capítulo 1. No G-PGF todas as búfalas receberam protocolo de superovulação semelhante ao G-C e, adicionalmente, receberam quatro doses de PGF2&#945; (0,53 mg i.m. de cloprostenol sódico) do D8 ao D10 com intervalo de 12h. Foi verificado maior número de estruturas embrionárias recuperadas em búfalas superovuladas tratadas com PGF2&#945; durante o período periovulatório (G-PGF=3,5±0,6) comparado ao grupo controle (G-C=2,3±0,5; P=0,02). Além disso, houve aumento no número de embriões transferíveis (G-PGF=2,7±0,6 vs. G-C=1,8±0,5; P=0,05). No Experimento 2 (Capítulo 2), os animais foram divididos aleatoriamente em três grupos experimentais: Grupo Controle (GC; n=22), Grupo PGF injetável (G-PGF-INJ; n=22) e Grupo PGF Bomba Osmótica (G-PGF-BO; n=22). Os animais pertencentes aos grupos: G-C e G-PGF-INJ foram submetidos aos mesmos protocolos descritos para seus grupos correspondentes no Experimento 1 (Capítulo 2). No GPGF- BO, todas as búfalas receberam protocolo de superovulação semelhante ao G-C e, adicionalmente, receberam a partir do D8 a inserção subcutânea de uma mini-bomba osmótica, contendo PGF2&#945; (2,12 mg de Cloprostenol sódico). A bomba osmótica retirada no D10. Não foram verificadas diferenças no número de estruturas totais recuperadas nas búfalas tratadas com PGF&#945; durante o período periovulatório (G-C=2,1±0,8 vs. G-PGF-INJ=2,1±0,6 vs. GPGF- BO=1,4±0,4; P=0,58). Os tratamentos no período periovulatório com dispositivo intravaginal de P4 (Capítulo 1) e com PGF2&#945; (Capítulo 2) não foram eficientes em aumentar a recuperação de estruturas embrionárias de búfalas superovuladas. / Despite numerous studies conducted in Brazil and world-wide, the use of superovulation (SOV) and embryo transfer (ET) biotechnologies in buffaloes still shows inconsistent results, particularly in terms of low embryos recovery rate. Thus, the aim of this study was to evaluate the use of a P4 device (to decrease contractility of the genital tract, Chapter 1) or PGF2&alpha; administration (to increase activity of the fimbriae and ciliary beat frequency, Chapter 2) during the periovulatory period in the uptake of oocytes by fimbriae and in the increase of embryo production in superovulated buffaloes. In Experiment 1 (Chapter 1), buffalo donors were homogeneously assigned into 2 groups: Control (C-G; n=8) and progesterone (P4) treatment during the periovulatory period (P4-G; n=8). Follicular growth wave emergence was synchronized with an intravaginal P4 device and the injection of 2 mg i.m. of estradiol benzoate at random stage of the estrous cycle (Day 0; D0). From D4 on, all buffaloes received 200 mg i.m. of FSH twice-daily, in 8 decreasing doses. A dose of PGF2&alpha; was given on D6 PM and on D7. The P4 was removed from the C-G on D7 and from the P4-G on D10. On D8, all buffaloes received 25 mg i.m. of pLH. Inseminations were done 12 and 24 h after the pLH treatment. Blood samples were collected every 12h from D7 to D11 for further progesterone assay. The embryonic structures (ova/embryos) were collected by nonsurgical uterine flush 6 days after the second timed AI (D14). Ovarian ultrasound examinations were performed on D8 and on D14 to verify respectively the superestimulation and the superovulatory response. Variables were analyzed by GLIMMIX procedure of SAS®. Buffaloes from P4-G showed lower ovulation rate (13.5±4.9 vs. 71.5±16.1%; P=0.002) and, consequently, higher follicles &ge; 8 mm rate (87.8±10.6 vs. 34.3±9.8 %; P=0.06) and lower number of CLs on D14 (1.1±0.3 vs. 8.0±2.8; P=0.04) than buffaloes from C-G. The total number of embryonic structures (1.9±0.7 vs. 0.0±0.0; P=0.03), transferable (1.6±0.7 vs. 0.0±0.0; P=0.04) and freezable embryos (1.6±0.7 vs. 0.0±0.0; P=0.04) were lower for P4-G. The serum progesterone concentration was greater for animals in P4-G (1.87±0.13) than in the C-G (0.48±0.10; P<0.0001). In Experiment 1 (Chapter 2), donors were randomly assigned into two groups: control (C-G; n=22) and prostaglandin F2&alpha; treatment during the periovulatory period (G-PGF; n=22). Animals from C-G were subjected to the superovulation protocol described on chapter 1. In G-PGF all buffaloes received similar superovulation protocol from the C-G and, additionally, received four doses of PGF2&alpha; (0.53 mg i.m. of sodic cloprostenol) from D8 to D10, 12h apart. A greater number of embryonic structures were recovered from superovulated buffaloes treated with PGF2&alpha; during the periovulatory period (PGF-G=3.5±0.6) compared to control group (C-G=2.3±0.5; P=0.02). Furthermore, increased number of transferable embryos were found in treated animals (PGF-G=2.7±0.6 vs. C-G=1.8±0.5; P=0.05). In Experiment 2 (Chapter 2), animals were randomly assigned into three experimental groups: Control group (CG; n=22), Injectable PGF group (INJ-PGF-G; n=22) and Osmotic pump PGF group (BO-PGF-G; n=22). The animals from C-G and INJ-PGF-G group were subjected to the same protocols described for their correspondent groups in Experiment 1 (Chapter 2). In BO-PGF-G, all buffaloes received the superovulation protocol similar to C-G and, additionally, received from D8, a subcutaneous insertion of a mini osmotic pump, containing PGF2&alpha; (2.12 mg de sodic cloprostenol). The osmotic pump was removed on D10. No differences were found on the total number of recovered structures in buffaloes treated with PGF2&alpha; during the periovulatory period (C-G=2.1±0.8 vs. INJ-PGF-G=2.1±0.6 vs. BO-PGF-G=1.4±0.4; P=0.58). Treatments on the peri- ovulatory period with intravaginal P4 device (Chapter 1) and PGF2&alpha; (Chapter 2) were not efficient in increasing the recovery of embryonic structures in superovulated buffalo.

O 17&#946;-E2 estimula a expressão de receptores endometriais, ER e OXTR. A ativação de OXTR induz a ativação da cadeia de síntese de PGF2&#945;. A hipótese do presente estudo é que as enzimas de síntese de PGF2&#945; são reguladas pelo 17&#946;-E2. Objetivou-se determinar os efeitos do 17&#946;-E2 na expressão gênica e proteica, assim como na localização de proteínas envolvidas na síntese de PGF2&#945;. Vacas Nelore multíparas, solteiras e cíclicas foram sincronizadas por aplicação de BE e inserção de dispositivo de P4. Após 8 dias realizou-se a remoção do dispositivo de P4 e aplicação de PGF2&#945;, seguido por 4 dias de observação de estro (D0=dia do estro). Entre D14 e D27 foram realizadas avaliações diárias da área do CL (cm2), fluxo sanguíneo (%) e concentração plasmática de progesterona (P4). No D15 as vacas foram divididas em três grupos: Controle (C; não tratado;N= 10), Placebo (P; 6mL de etanol 50%; IV; N= 21) e Estradiol (E; 3mg 17&#946;-E2; 6mL de etanol 50%; IV;N=21). Subsequente aos tratamentos, biópsias uterinas foram coletadas nos tempos 0h (C; N=10); 4h (E4h, N=11 e P4h; N=10) ou 7h (E7h, N=10 e P7h, N=11). Amostras de sangue foram obtidas nos tempos 0h a 7h, para mensuração das concentrações PGFM no D15. O grupo E apresentou acentuada diminuição da área do CL, fluxo sanguíneo e concentração de P4 (P&lt;0,05), comparado ao grupo P. Comparado ao grupo P, as vacas do grupo E anteciparam o dia da luteólise funcional e estrutural em 2 e 3 dias, respectivamente. O grupo E apresentou maior concentração de PGFM nos tempos 4h, 6h e 7h (P&lt;0,05), comparado ao grupo P. A quantificação dos transcritos realizada por qPCR (N=6/grupo). Na hora 4, a abundância dos genes ESR1, ESR2, PRKC&#945;, PRKC&#946;, PLA2G4, AKR1B1 e AKR1C4 foi menor nas amostras E4h, enquanto OXTR foi maior nas mesmas amostras comparando-se com as amostras P4h (P&lt;0,05). A expressão gênica de PTGS2 não diferiu entre os grupos E4h e P4h (P&gt;0,05). Na hora 7, as amostras E7h também apresentaram menor abundância de ESR1, PRKC&#945;, PRKC&#946;, AKR1B1 e AKR1C4 (P&lt;0,05) e houve tendência para menor expressão de ESR2, comparado às amostras P7h. Contudo, não houve diferença na abundância de OXTR, PLA2G4 e PTGS2 entre as amostras E7h e P7h (P&gt;0,05). A abundância da enzima PKC&#945; analisada por Western Blotting (N=3/grupo) foi diminuída tanto nas amostras E4h como nas E7h, em relação às amostras P4h e P7h, respectivamente. Na avaliação por imunohistoquímica (N=5/grupo), o grupo E4h apresentou maior imunomarcação de PGR no epitélio glandular (P&lt; 0,05) e houve tendência para maior imunomarcação de PKC&#978; no epitélio luminal, comparado ao grupo P4h (P=0,08). Houve tendência para menor imunomarcação de ER&#945; no epitélio glandular do grupo E4h comparado ao grupo E7h (P=0,1). Concluí-se que a aplicação do 17&#946;-E2 levou a redução da maioria dos transcritos das moléculas de síntese de PGF2&#945;, assim como da abundância de PKC&#945;. O possível mecanismo para a estimulação de PGFM por 17&#946;-E2 pode incluir o aumento da ativação de enzimas que participam na cascata de síntese de PGF2&#945;. / 17&#946;-E2 stimulates the expression of endometrial receptors, ER and OXTR. Activation of OXTR induces the activation of the synthesis of PGF2&#945; pathway. The central hypothesis is that the enzymes involved in PGF2 synthesis are reguleted by 17&#946;-E2. The objective of this study was to determine the effects of 17&#946;-E2 on gene and protein expression and localization of the enzymes involved in PGF2&#945; synthesis. Multiparous, non-lactating and cyclic Nelore cows were synchronized by BE application and P4 device insertion. After 8 days the P4 device was removed and a single dose of PGF2&#945; applied, followed by 4 days of estrus detection (D0 = day of estrus). Daily measurements of CL area (cm2), blood flow (%), and plasma progesterone concentration (P4) were performed between D14 and D27. On D15 cows were divided into three groups: Control (C, untreated, N = 10), Placebo (P; 6mL of ethanol 50%, IV; N = 21) and Estradiol (E; 3mg 17&#946;-E2; Ethanol 50%, IR: N = 21). After the treatments administration, uterine biopsies were collected at times 0h (C; N = 10); 4h (E4h, N = 11 and P4h, N = 10) or 7h (E7h, N = 10 and P7h, N = 11). Blood samples were obtained from time 0h to 7h for the measurement of the PGFM concentrations on D15. Group E showed a marked decrease in CL area, blood flow, and P4 concentration (P &lt;0.05) compared to group P. Also, when compared to group P, cows from group E anticipated the day of functional and structural luteolysis in 2 and 3 days, respectively. Group E presented higher concentration of PGFM at 4h, 6h and 7h (P &lt;0.05), compared to group P. The transcripts abundance was performed by qPCR (N = 6 / group). The transcripts abundance of ESR1, ESR2, PRKC&#945;, PRKC&#946;, PLA2G4, AKR1B1, and AKR1C4 genes was lower in the E4h samples, while OXTR was higher in the same samples compared to the P4h (P &lt;0.05) samples in the time 4h. The gene expression of PTGS2 did not differ between groups E4h and P4h (P&gt; 0.05). At time 7h, samples E7h also had lower abundance of ESR1, PRKC&#945;, PRKC&#946;, AKR1B1 and AKR1C4 (P &lt;0.05) and there was a tendency for lower ESR2 expression, compared to samples P7h. Nevertheless, there was no difference in the abundance of OXTR, PLA2G4, and PTGS2 between samples E7h and P7h (P&gt; 0.05). The abundance of the PKC&#945; enzyme analyzed by Western Blotting (N = 3 / group) was decreased in both the E4h and E7h samples, relative to the samples P4h and P7h, respectively. In the evaluation by immunohistochemistry (N = 5 / group), the E4h group presented greater PGR immunostaining in the glandular epithelium (P &lt;0.05) and there was a tendency for a greater immunostaining of PKC&#978; in the luminal epithelium, compared to the P4h group (P = 0,08). There was a tendency for lower ER&#945; immunostaining in the glandular epithelium of the E4h group compared to the E7h group (P = 0.1). It was concluded that the application of 17&#946;-E2 led to the reduction of most of the transcripts of the PGF2&#945; synthesis molecules, as well as the abundance of PKC&#945;. The possible mechanism for stimulation of PGFM by 17&#946;-E2 may include increased activation of enzymes that participate in the cascade of PGF2&#945; synthesis.

A fagocitose de células apoptóticas, também denominada eferocitose, é um processo dinâmico e de fundamental importância para homeostase dos tecidos após uma injúria. Estudos demonstraram previamente que a fagocitose de células apoptóticas promove a síntese de mediadores anti-inflamatórios como PGE2, TGF-? e IL-10, podendo resultar num microambiente supressor e aumento da susceptibilidade do hospedeiro contra agentes infecciosos. Entretanto, a fagocitose de células apoptóticas infectadas por células dendríticas promove a geração não apenas de citocinas anti-inflamatórias como TGF-?, mas também de IL-6 e IL-23, levando a um efeito imunoestimulador, a diferenciação de células Th17. A atuação da PGE2 na imunidade adaptativa vem sendo investigada quanto à diferenciação e ativação de linfócitos Th1, Treg e Th17. Nossos resultados demonstram que a fagocitose de células apoptóticas infectadas com E. coli promove a ativação e migração de células dendríticas, assim como a produção de citocinas pró- e anti-inflamatórias e altos níveis de PGE2. No entanto, diferente da hipótese inicial, a presença de altas concentrações de PGE2 inibe drasticamente a diferenciação de células Th17 no contexto de fagocitose de células apoptóticas infectadas com E. coli por células dendríticas, in vitro. O tratamento de linfócitos T CD4+naive com antagonistas e agonistas de EP2/EP4 demonstram que o efeito supressor de PGE2 é mediado primordialmente pelo receptor EP4. Por fim, nossos resultados in vivo comprovam os resultados obtidos in vitro, demonstrando o papel supressor de PGE2 na diferenciação de células Th17 no contexto de fagocitose de células apoptóticas infectadas em modelo de infecção pulmonar. / The phagocytosis of apoptotic cells, also called efferocytosis, is a dynamic process critical for tissue homeostasis after injury. We and other groups previously have shown that phagocytosis of apoptotic cells promotes the synthesis of anti-inflammatory mediators such as PGE2, TGF-? and IL-10, that may result in the suppression of host defense against microorganisms. However, an elegant study using infected apoptotic cells showed that phagocytosis of these cells promote not only the generation of anti-inflammatory cytokines such as TGF-? but also IL-6 and IL-23, resulting in an immunostimulatory effect, the differentiation of Th17 cells. The role of PGE2 in adaptive immunity has been investigated regarding differentiation and activation of Th1, Th17 and Treg. Our results demonstrate that engulfment of E.coli infected apoptotic cells promotes the activation and migration of dendritic cells as well as production of pro and anti-inflammatory cytokines together with high levels of PGE2. However, differing from our hypothesis, high levels of PGE2 inhibits drastically the differentiation of Th17 cells on the context of engulfment of E.coli infected apoptotic cells by dendritic cells in vitro. The treatment of T CD4+naive cells with antagonist or agonists of EP2/EP4 receptors demonstrates the suppressor effect is mainly mediated by EP4 receptor. Finally, the instillation of E.coli infected apoptotic cells in E.coli infected animals resulted on modest Th17 increase but treatment with cox inhibitor increased Th17 cell differentiation. Therefore, our in vivo results prove the in vitro results.

Human anaphylatoxin C3a increases glycogenolysis in perfused rat liver. This action is inhibited by prostanoid synthesis inhibitors and prostanoid antagonists. Because prostanoids but not anaphylatoxin C3a can increase glycogenolysis in hepatocytes, it has been proposed that prostanoid formation in nonparenchymal cells represents an important step in the C3a-dependent increase in hepatic glycogenolysis. This study shows that (a) human anaphylatoxin C3a (0.1 to 10 mug/ml) dose-dependently increased prostaglandin D2, thromboxane B, and prostaglandin F2alpha formation in rat liver macrophages (Kupffer cells); (b) the C3a-mediated increase in prostanoid formation was maximal after 2 min and showed tachyphylaxis; and (c) the C3a-elicited prostanoid formation could be inhibited specifically by preincubation of C3a with carboxypeptidase B to remove the essential C-terminal arginine or by preincubation of C3a with Fab fragments of a neutralizing monoclonal antibody. These data support the hypothesis that the C3a-dependent activation of hepatic glycogenolysis is mediated by way of a C3a-induced prostanoid production in Kupffer cells.

In cultured rat hepatocytes the key gluconeogenic enzyme phosphoenolpyruvate carboxykinase (PCK) is known to be induced by glucagon via an elevation of cAMP. Prostaglandin E₂ has been shown to antagonize the glucagon-activated cAMP formation, glycogen phosphorylase activity and glucose output in hepatocytes. It was the purpose of the current investigation to study the potential of PGE₂ to inhibit the glucagon-induced expression of PCK on the level of mRNA and enzyme activity. PCK mRNA and enzyme activity were increased by 0.1 nM glucagon to a maximum after 2 h and 4 h, respectively. This increase was completely inhibited if 10 μM PGE2 was added concomitantly with glucagon. This inhibition by PGE₂ of glucagon-induced PCK activity was abolished by pertussis toxin treatment. When added at the maximum of PCK mRNA at 2 h, PGE₂ accelerated the decay of mRNA and reduced enzyme activity. This effect was not reversed by pertussis toxin treatment. Since in liver PGE₂ is derived from Kupffer cells, which play a key role in the local inflammatory response, the present data imply that during inflammation PGE₂ may reduce the hepatic gluconeogenic capacity via a Gᵢ-linked signal chain.

Rat hepatocytes have previously been reported to possess prostaglandin E₂ receptors of the EP₃-type (EP₃-receptors) that inhibit glucagonstimulated glycogenolysis by decreasing cAMP. Here, the isolation of a functional EP₃ϐ receptor cDNA clone from a rat hepatocyte cDNA library is reported. This clone can be translated into a 362-amino-acid protein, that displays over 95% homology to the EP₃ϐ receptor from mouse mastocytoma. The amino- and carboxy-terminal region of the protein are least conserved. Transiently transfected HEK 293 cells expressed a single binding site for PGE₂ with an apparent Kd of 15 nM. PGE₂ > PGF₂α > PGD₂ competed for [³H]PGE₂ binding sites as did the EP₃ receptor agonists M&B 28767 = sulprostone > misoprostol but not the EP₁ receptor antagonist SC 19220. In stably transfected CHO cells M&B 28767 > sulprostone = PGE₂ > misoprostol > PGF₂α inhibited the forskolin-elicited cAMP formation. Thus, the characteristics of the EP₃ϐ receptor of rat hepatocytes closely resemble those of the EP₃ϐ receptor of mouse mastocytoma.

Surfactant proteins SP-A and SP-D are important key molecules responsible for pulmonary homeostasis and innate immunity against infectious pathogens. SP-A and SP-D are also found in various parts of the placenta as well as amniotic fluid. The levels of these proteins in the amniotic fluid are good biomarkers of fetal lung maturation. The development of the lungs in fetal growth is important for fetal survival in extrauterine life. In pregnant mice models, a huge increase in SP-A and SP-D levels in the amniotic sac has been reported close to parturition suggesting an important role of these proteins in the hormonal pathway to labour. In this thesis, full length natural and recombinant proteins of human SP-A and SP-D were generated and examined on the maternal-fetal tissues of the placenta (explants of amnion, chorion and decidua) under inflammatory conditions. A range of innate and adaptive immune markers and prostaglandin targets were examined to show that SP-A and SP-D modulate the prostaglandin pathway. Thus, an imbalance in this could potentially lead to disorders such as intrauterine growth retardation and preeclampsia. The cellular basis of immune regulation and prostaglandin pathway was also examined via fractionation of decidual macrophages. Curiously, SP-A and SP-D appears to suppress pro-inflammatory response of decidual macrophages after challenging with LPS. This thesis thus divulges specific and mutually inclusive functions of SP-A and SP-D in the maintenance of pregnancy, protection against intrauterine infection, dampening of inflammation, and premature activation of parturition.

Macrophages are cells of the innate immune system that can be found in large quantities in cancer tumors and affect cancer progression by regulating growth and invasiveness of cancer cells. There are two main phenotypes of macrophages denoted M1 and M2. In this thesis, the M1 and M2 phenotype of human macrophages were characterized, and effects of the macrophages on the growth and invasiveness of colon and lung cancer cells were studied. Macrophages of the M1 phenotype, but not the M2 phenotype, inhibited growth of both colon and lung cancer cells, and the inhibition for some of the cancer cell lines was induced by cell cycle arrest in the G1/G0 and/or G2/M cell cycle phases. In the colon cancer cell line, the macrophage induced cell cycle arrest was found to attenuate the cytotoxic effect of the chemotherapeutic drug 5-FU. Macrophages were also shown to express high levels of proteases (matrix metalloproteinase-2 and 9) and high levels of proteins of the urokinase-type plasminogen activator (uPA) system, in comparison to the lung cancer cell lines studied. Expression of these has been found to predict poor outcome in lung cancer, and the results suggest macrophages to be important contributors of these in lung tumors. Furthermore, the M1 phenotype was found to express higher levels of the uPA receptor than the M2 phenotype. Prostaglandin E2 (PGE2) is a potent inflammatory molecule expressed by e.g. macrophages and monocytes, and inhibition of its expression has been shown to reduce the risk of colon cancer. Green tea and black tea was found to be potent inhibitors of PGE2 formation in human monocytes, and the inhibitory effects of green tea was likely due to its content of the polyphenol epigallocatechin gallate. Rooibos tea also inhibited PGE2 formation, but was less potent than green and black tea. The primary mechanism for the inhibition was via inhibition of expression of enzymes in the PGE2 formation pathway, and primarily microsomal prostaglandin synthase-1. / Macrophages are cells of the immune system often found in large numbers in cancer tumors. They affect multiple aspects of cancer progression, including growth and spread of cancer cells, and the efficacy of treatments. There are two major macrophage phenotypes denoted M1 and M2, that have mainly pro- and anti-inflammatory properties, respectively. In this thesis, M1 and M2 macrophages were characterized and effects of them on different aspects of cancer progression were studied using culture of colon, and lung cancer cells. The M1 phenotype inhibited proliferation of cancer cells from both colon and lung. The growth inhibition was for some cell lines accompanied by cell cycle arrest. The macrophage induced cell cycle arrest was found to protect colon cancer cells from the cytostatic drug 5-fluorouracil. Prostaglandin E2 (PGE2) contributes to colon cancer development and treatment of monocytes with tea extracts inhibited PGE2 formation via inhibition of expression of microsomal prostaglandin E synthase-1. Proteases can degrade the extracellular matrix of a tumor to facilitate cancer cell invasion and metastasis. The M1 and M2 phenotypes of macrophages expressed several protease activity related genes to a greater extent than lung cancer cells, and M1 more so than the M2 phenotype.