Preeclampsia and molar pregnancy are two devastating placental pathologies characterized by an immature proliferative trophoblast phenotype accompanied by excessive cell death. It is therefore of paramount importance to study the regulation of cell fate in the placenta, to gain a further understanding of the mechanisms that contribute to these diseases. In this dissertation we report that during normal placental development and in preeclampsia, Matador (Mtd), a pro-apoptotic member of the Bcl-2 family, has a dual function in regulating trophoblast cell proliferation and death. Importantly, we reveal a novel role of Mtd-L in promoting cyclin E1 expression and cell cycle progression. Of clinical importance, we also identify that both cyclin E1 and the CDK inhibitor p27, are increased in severe early onset preeclampsia. However, the inhibitory function of p27 in this pathology may be hampered due to its increased phosphorylation at Ser10, resulting in its nuclear export. Of equal importance, data presented demonstrate that placentae from severe early onset preeclampsia display a molecular profile distinct from late onset preeclampsia or intrauterine growth restricted pregnancies. In the final data chapter we demonstrate that Mtd is highly expressed in molar tissue, where it localizes to both apoptotic and proliferative cells. Our data suggests that an abundance of Mtd and cyclin E1 in conjunction with the low level of p27 may contribute to the hyperproliferative nature of the disorder. The body of work in this dissertation uncovers novel insights into the regulation of trophoblast cell fate. Importantly, the impact of Mtd on cyclin E1 to promote G1-S transition is a novel mechanism found to regulate trophoblast cell proliferation in normal and pathological placentation. Equally important is our identification of molecular differences between placental pathologies that may help to differentiate early and late onset preeclampsia, IUGR and molar pregnancy.

Preeclampsia and molar pregnancy are two devastating placental pathologies characterized by an immature proliferative trophoblast phenotype accompanied by excessive cell death. It is therefore of paramount importance to study the regulation of cell fate in the placenta, to gain a further understanding of the mechanisms that contribute to these diseases. In this dissertation we report that during normal placental development and in preeclampsia, Matador (Mtd), a pro-apoptotic member of the Bcl-2 family, has a dual function in regulating trophoblast cell proliferation and death. Importantly, we reveal a novel role of Mtd-L in promoting cyclin E1 expression and cell cycle progression. Of clinical importance, we also identify that both cyclin E1 and the CDK inhibitor p27, are increased in severe early onset preeclampsia. However, the inhibitory function of p27 in this pathology may be hampered due to its increased phosphorylation at Ser10, resulting in its nuclear export. Of equal importance, data presented demonstrate that placentae from severe early onset preeclampsia display a molecular profile distinct from late onset preeclampsia or intrauterine growth restricted pregnancies. In the final data chapter we demonstrate that Mtd is highly expressed in molar tissue, where it localizes to both apoptotic and proliferative cells. Our data suggests that an abundance of Mtd and cyclin E1 in conjunction with the low level of p27 may contribute to the hyperproliferative nature of the disorder. The body of work in this dissertation uncovers novel insights into the regulation of trophoblast cell fate. Importantly, the impact of Mtd on cyclin E1 to promote G1-S transition is a novel mechanism found to regulate trophoblast cell proliferation in normal and pathological placentation. Equally important is our identification of molecular differences between placental pathologies that may help to differentiate early and late onset preeclampsia, IUGR and molar pregnancy.

<p>Mast cells are long-lived effector cells of importance for both acute and chronic inflammations. Mast cells can be activated in many different ways, leading to the release of inflammatory mediators. In contrast to most other inflammatory cells, activated mast cells have the capacity to recover, regranulate and thereby be activated again. </p><p>In this thesis I have investigated the mechanisms involved in regulating activation-induced mast cell survival. We have found that cross-linking of FcεRI-bound IgE with an antigen (IgER-CL) induces a survival program in mast cells. Upon IgER-CL, mouse and human mast cells upregulate the pro-survival Bcl-2 family gene A1/Bfl-1. A1^-/- mast cells degranulate upon FcεRI activation but they cannot recover most likely due to the lack of A1. Sensitized and provoked A1^-/- mice exhibit lower amounts of mast cells compared to littermate controls. In contrast to mast cells, no Bfl-1 expression or survival promotion can be detected in basophils after IgER-CL. Another mast cell secretagogue, an adenosine receptor agonist, neither promoted upregulation of A1 nor survival.</p><p>Although it is well established that mast cell survival is dependent on stem cell factor (SCF), it has not been described how this process is regulated. We have found that SCF promotes survival through Akt-mediated inhibition of the forkhead transcription factor FOXO3a and its transcriptional target Bim, a BH3-only pro-apoptotic protein. SCF-treatment prevents upregulation of Bim protein expression and leads to an upregulation of Bim phosphorylation through PI3-kinase and MEK-dependent pathways. Overexpression of FOXO3a causes an upregulation of Bim and induces mast cell apoptosis, even in the presence of SCF. </p><p>Taken together, the work in this thesis demonstrates that A1/Bfl-1 and Bim play key roles in mast cell survival. These findings might be of importance in understanding the mechanisms of mast cell longevity and hence for possible new therapeutics used for mast cell-associated inflammations.</p>

Mast cells are long-lived effector cells of importance for both acute and chronic inflammations. Mast cells can be activated in many different ways, leading to the release of inflammatory mediators. In contrast to most other inflammatory cells, activated mast cells have the capacity to recover, regranulate and thereby be activated again. In this thesis I have investigated the mechanisms involved in regulating activation-induced mast cell survival. We have found that cross-linking of FcεRI-bound IgE with an antigen (IgER-CL) induces a survival program in mast cells. Upon IgER-CL, mouse and human mast cells upregulate the pro-survival Bcl-2 family gene A1/Bfl-1. A1-/- mast cells degranulate upon FcεRI activation but they cannot recover most likely due to the lack of A1. Sensitized and provoked A1-/- mice exhibit lower amounts of mast cells compared to littermate controls. In contrast to mast cells, no Bfl-1 expression or survival promotion can be detected in basophils after IgER-CL. Another mast cell secretagogue, an adenosine receptor agonist, neither promoted upregulation of A1 nor survival. Although it is well established that mast cell survival is dependent on stem cell factor (SCF), it has not been described how this process is regulated. We have found that SCF promotes survival through Akt-mediated inhibition of the forkhead transcription factor FOXO3a and its transcriptional target Bim, a BH3-only pro-apoptotic protein. SCF-treatment prevents upregulation of Bim protein expression and leads to an upregulation of Bim phosphorylation through PI3-kinase and MEK-dependent pathways. Overexpression of FOXO3a causes an upregulation of Bim and induces mast cell apoptosis, even in the presence of SCF. Taken together, the work in this thesis demonstrates that A1/Bfl-1 and Bim play key roles in mast cell survival. These findings might be of importance in understanding the mechanisms of mast cell longevity and hence for possible new therapeutics used for mast cell-associated inflammations.

Le glycolipide Gb3/CD77 qui est fortement exprimé en surface des cellules de lymphome de Burkitt (LB) est le récepteur d’une toxine bactérienne la Vérotoxine-1 (VT-1). Notre équipe a montré précédemment que, dans les cellules de LB, la VT-1 induit une cascade apoptotique mettant en jeu les caspases et la mitochondrie. Mon travail a consisté à poursuivre l’analyse des bases moléculaires de ce processus, notamment en m’intéressant au rôle de la protéine pro-apoptotique Bid. Bid est un membre de la famille Bcl-2 qui est clivé par la caspase-8 au cours de l’apoptose et dont la forme tronquée (t-Bid) se relocalise à la mitochondrie. Grâce à l’utilisation de clones cellulaires de LB où Bid a été inhibée puis réexprimée sous forme non clivable et d’un inhibiteur de la caspase-8, nous avons montré que lors de l’apoptose induite par la VT1 : 1) la protéine entière Bid (full-length Bid ou FL-Bid) contrôle l’activation de protéines pro-apoptotiques Bax et de Bak ; 2) t-Bid et FL-Bid sont, toutes les deux, impliquées dans la libération des protéines pro-apoptotiques (cytochrome c et Smac/DIABLO) de l’espace intermembranaire de la mitochondrie vers le cytosol ; 3) FL-Bid contrôle l’homodimérisation de Bax et de Bak qui contribuerait à la libération initiale du cytochrome c et de Smac/DIABLO alors que t-Bid est nécessaire à l’hétérodimérisation de Bax et Bak qui permettrait l’amplification de cette libération. L’ensemble de ces résultats montre donc une coopération fonctionnelle entre Bax et Bak au cours de l’apoptose induite par la VT-1 et surtout met en évidence que l’activation de la voie caspase-8/t-Bid n’est absolument pas requise pour initier la mort cellulaire.Gb3/CD77 est aussi exprimé à la surface de certains lymphocytes B normaux, où il constitue un marqueur de différenciation mais sa fonction endogène reste encore indéterminée. Une deuxième partie de mon travail a consisté à essayer d’identifier le ligand physiologique de Gb3/CD77 pour comprendre son rôle biologique. Grâce à une analyse en spectrométrie de masse, nous avons identifié deux protéines potentiellement partenaires de Gb3/CD77 : la galectine-7 et la protéine S100A11. / The Gb3/CD77 glycolipid, which is strongly expressed in Burkitt's lymphoma (BL) cells, is a receptor for the bacterial toxin Verotoxin-1 (VT-1). Previously, our group has shown that VT-1 induces an apoptotic pathway in BL cells which is dependent on caspases and mitochondria. Here, we provide new insights into this pathway. A pro-apoptotic member in the Bcl-2 family, Bid is cleaved by caspase-8 and its truncated form t-Bid is translocated to mitochondria. Using LB cell clones where Bid was inhibited prior to being reexpressed as a non-cleavable mutated form (BID D59A) and a caspase-8 inhibitor to explore VT-1-induced apoptosis, we showed that 1) the full length Bid (FL-Bid) controls the activation of pro-apoptotic proteins Bax and Bak; 2) Both t-Bid and FL-Bid are involved in the release of pro-apoptotic proteins (cytochrome c and Smac/DIABLO) from the mitochondrial intermembrane space to the cytosol; 3) FL-Bid controls the homo-oligomerization of both Bax and Bak, likely contributing to the initial release of cytochrome c and Smac/DIABLO while t-Bid is needed for their hetero-oligomerization followed by amplification of the release. Together, these results reveal a functional cooperation between Bax and Bak during VT-1-induced apoptosis and, most importantly, that activation of caspase-8 and t-Bid is not required to induce the onset of cell death. Gb3/CD77 is also expressed in a proportion of normal B-lymphocytes where it constitutes a differentiation marker but whose function remains uncharacterized. In an effort to look for physiological ligands, we have used a biochemical approach followed by mass spectrometry analysis. Two proteins have been identified as potentially Gb3/CD77 partners, namely galectin-7 and protein S100A11.

O diabetes mellitus tipo 1 (DM-1) e a esclerose múltipla (EM) são doenças auto-imunes órgão-específicas, inflamatórias, mediadas por células T e B auto-reativas e caracterizadas pela destruição seletiva de células b pancreáticas produtoras de insulina e do sistema nervoso central, respectivamente. Acredita-se que a desregulação da expressão de genes reguladores da maquinaria apoptótica possa contribuir para o desenvolvimento da auto-imunidade, visto que algumas dessas moléculas participam nos processos de tolerância central e periférica de linfócitos auto-reativos. O objetivo deste projeto foi analisar a expressão de moléculas reguladoras das vias intrínseca, extrínseca e da Família de proteínas inibidoras da apoptose (IAP) em 33 indivíduos saudáveis, 15 pacientes com DM-1 e 18 com EM submetidos à terapia de imunossupressão em altas doses seguida do transplante autólogo de células-tronco hematopoéticas (IAD/TACTH). As células mononucleares (CMN) foram isoladas do sangue periférico dos controles e de pacientes nos períodos pré-mobilização (pré-mob), pré-condicionamento (pré-cond), D+180, D+360, D+540 e D+720 pós-transplante. As CMN foram utilizadas para extração de RNA, síntese de cDNA, quantificação da expressão por PCR em tempo real dos genes a1, bcl-2, bcl-w, bcl-xL, mcl-1, bad, bak, bax, bid, bik, bim, bok, noxa, fas, fasL, c-FLIPL, cIAP-1 e cIAP-2 e protéica de Bcl-2, Bcl-xL, Bak, Bim e c-FLIPL por western-blotting. Os resultados de expressão gênica foram representados por unidades relativas de expressão em medianas nas diferentes amostras. Os pacientes com DM-1 apresentaram diminuição da expressão dos genes anti-apoptóticos bcl-2 (mediana: 0,98; p=0,04), bcl-w (0,08; p=0,04), mcl-1 (1254; p=0,03) e cIAP-1 (1,24; p=0,003) nas CMN dos pacientes no período pré-mob em relação aos indivíduos saudáveis (medianas: bcl-2: 7,58; bcl-w: 0,52; mcl-1: 1659; cIAP-1: 14,5), enquanto a expressão de cIAP-2 (60,8; p=0,0005) estava aumentada em relação aos controles (23,3). Foi observada redução significativa na expressão dos genes pró-apoptóticos bad (0,002; p<0,0001), bax (0,01; p=0,002) e fasL (1,66; p=0,001) no período pré-mob comparada aos controles sadios (bad: 0,23; bax: 2,79; fasL: 3,56). Os níveis de RNAm de bid (0,10; p=0,001) e bok (0,72; p=0,006) estavam elevados no pré-mob em relação ao grupo controle (bid: 0,004; bok: 0,31). As moléculas bcl-2, bcl-w, bcl-xL, mcl-1, bad, bax, bok, fasL e cIAP-1 atingiram níveis de RNAm similares aos controles após o TACTH. Foi verificado que a expressão de bcl-w, cIAP-1 e noxa estava maior nos pacientes com DM-1 em remissão quando comparados àqueles em recaída. A diminuição da expressão de a1, bcl-2 e bcl-w e o aumento de fas e noxa correlacionaram-se às porcentagens de hemoglobina glicosilada, concentração de auto-anticorpos GAD65, e aos níveis séricos de peptídeo-C após o transplante. Os pacientes com EM mostraram uma expressão reduzida dos genes anti-apoptóticos bcl-w (0,11; p=0,02) e cIAP-1 (1,87; p=0,04) no pré-mob comparada aos valores dos controles (bcl-w: 0,27; cIAP-1: 7,75) e maior expressão dos genes a1 (90,8; p=0,001) e cIAP-2 (58,8; p=0,009) em relação aos controles (a1: 12,7; cIAP-2: 22,3). As moléculas pró-apoptóticas bad (0,007; p=0,01) e bax (0,0007; p=0,004) mostraram menor expressão nas CMN no período pré-mob do que nos controles (bad: 0,27; bax: 1,24). Os genes bid (20,7; p=0,004), bik (0,84; p=0,02) e bok (1,77; p=0,0001) possuíam maior expressão no período pré-mob em relação aos indivíduos sadios (bid: 2,64; bik: 0,33; bok: 0,26). Não foram observadas diferenças significativas na expressão das moléculas da via extrínseca da apoptose nos pacientes com EM (p>0,05) nos períodos avaliados. Os valores de expressão de bcl-w, bak, bax, bik, bok e cIAP-1 atingiram níveis semelhantes aos controles após o transplante. A expressão dos genes bcl-2, cIAP-1, bad e bax estava maior nos pacientes em remissão da EM quando comparados àqueles em progressão neurológica. O aumento da expressão dos genes pró-apoptóticos bax, bak e bimEL correlacionou-se inversamente aos valores de EDSS dos pacientes com EM após o TACTH. Os resultados de expressão protéica foram equivalentes aos de expressão gênica nas duas doenças, com exceção dos dados das proteínas Bcl-2 e Bim. Em conjunto, os resultados demonstraram a desregulação da expressão de várias moléculas anti- e pró-apoptóticas nas CMN dos pacientes com DM-1 e EM. Esses achados sugerem a associação de alterações nos processos de apoptose celular com o surgimento e persistência de células auto-reativas no DM-1 e EM. Os dados indicam que essas alterações, principalmente a diminuição da expressão de moléculas pró-apoptóticas, como bak e bax, possam contribuir para a patogênese do DM-1 e EM. Além disso, a terapia de IAD/TACTH foi capaz de modular a expressão da maioria dos genes anormalmente expressos nas CMN dos pacientes com DM-1 e EM, já que esses atingiram níveis de expressão similares ao grupo controle após o transplante. Esta normalização da expressão de vários genes analisados correlacionou-se com a remissão clínica da doença na maioria dos pacientes / Type 1 diabetes mellitus (T1DM) and multiple sclerosis (MS) are inflammatory, organ-specific autoimmune diseases characterized by selective destruction of insulin-producing pancreatic -cells and central nervous system, respectively, by autoreactive B and T cells. Deregulation of apoptotic machinery is supposed to contribute to self-tolerance breakdown and autoimmune diseases pathogenesis, since apoptotic molecules have an important role in B and T lymphocytes central and peripheral tolerance mechanisms. The aim of this study was to evaluate the expression of pro and anti-apoptotic molecules from intrinsic and extrinsic apoptotic pathways and IAP Family members in 33 healthy individuals, 15 T1DM and 18 MS patients submitted to high-dose immunossupression therapy followed by autologous hematopoietic stem cell transplantation (HDI/AHSCT). Peripheral blood mononuclear cells (PBMC) were isolated from controls and patients at pre-mobilization (pre-mob), pre-conditioning (pre-cond), D+180, D+360, D+540 and D+720 post-transplantation. PBMC were used for RNA extraction, cDNA synthesis, gene quantification of a1, bcl-2, bcl-w, bcl-xL, bad, bak, bax, bid, bik, bimEL, bok, noxa, fas, fasL, c-FLIPL, cIAP-1 and cIAP-2 by Real Time PCR and Bcl-2, Bcl-xL, Bak, BimEL and c-FLIPL proteins detection by western-blotting. Results are expressed as median of relative expression units. Results from T1DM patients indicated that antiapoptotic molecules bcl-2 (median: 0,98; p=0,04), bcl-w (0,08; p=0,04), mcl-1 (1254; p=0,03) and cIAP-1 (1,24; p=0,003) were downregulated at pre-mob compared with healthy controls (medians bcl-2: 7,58; bcl-w: 0,52; mcl-1: 1659; cIAP-1: 14,5), while cIAP-2 (60,8; p=0,0005) gene expression was upregulated compared to healthy controls (23,3). We observed a significant decrease in proapoptotic bad (0,002; p<0,0001), bax (0,01; p=0,002) and fasL (1,66; p=0,001) genes expression in patients PBMC at pre-mob period compared to healthy subjects (bad: 0,23; bax: 2,79; fasL: 3,56). mRNA levels of bid (0.10; p=0.001) and bok (0.72; p=0.006) were elevated at pre-mob period when compared to control group (bid: 0.004; bok: 0.31). The bcl-2, bcl-w, bcl-xL, mcl-1, bad, bak, bax, bok, fasL and cIAP-1 mRNA levels reached controls levels after HDI/AHSCT. We observed that bcl-w, cIAP-1 and noxa gene expression were increased in T1DM patients in remission when compared to relapsed patients. The decreased antiapoptotic gene expression and increased in proapoptotic molecules correlated with decreased glicosilated hemoglobin percentages (Hb A1C) and anti-GAD65 antibodies and increased peptide-C levels. Results from MS patients showed decreased bcl-w (0,11; p=0,02) and cIAP-1 gene expression (1,87; p=0,04) in patients PBMC at pre-mob period compared to healthy controls (bcl-w: 0,27; cIAP-1: 7,75) and increased expression of a1 (90,8; p=0,001) and cIAP-2 (58,8; p=0,009) compared to controls (a1: 12,7; cIAP-2: 22,3). Proapoptotic molecules bad (0.007; p=0.01) and bax (0.0007; p=0.004) showed decreased gene expression at pre-mob compared to control group (bad: 0.27; bax: 1.24). bid (20.7; p=0.004), bik (0.84; p=0.01) and bok genes (1.77; p=0.0001) showed increased expression at pre-mob compared to healthy controls (bid: 2.64; bik: 0.33; bok: 0.26). Significant differences were not observed in the expression of the extrinsic pathway genes in pre-mob and healthy controls samples (p>0.05). bcl-w, bak, bax, bik, bok and cIAP-1 expression values reached healthy control values after transplantation. We observed that bcl-2, cIAP-1, bad and bax gene expression was increased in MS patients in disease remission when compared to patients with neurologic progression. Significant correlation of increased proapoptotic genes expression with decreased EDSS values in MS patients after HDI/AHSCT was observed. Results of protein quantification of apoptotic molecules in PBMC of T1DM and MS patients were similar to the gene expression results of these molecules, except for Bcl-2 and Bim proteins. Taken together, these data indicate a deregulated expression of anti- and proapoptotic genes in T1DM and MS patients PBMC. These data suggest an association of deregulated apoptosis with emergence and maintenance of autoreactive lymphocytes in analyzed patients. Based on these results, we suggest that this altered gene expression profile, mainly the decreased proapoptotic genes expression, as bak and bax, may contribute to T1DM and MS pathogenesis. Furthermore, we showed that the HDI/AHSCT therapy was able to modulate and normalize the expression of most genes abnormally expressed in T1DM and MS patients at pre-transplant period. Many analyzed genes achieved expression levels similar to healthy controls. The normalization of the expression of many evaluated genes correlated to disease remission in the majority of the patients.

O diabetes mellitus tipo 1 (DM-1) e a esclerose múltipla (EM) são doenças auto-imunes órgão-específicas, inflamatórias, mediadas por células T e B auto-reativas e caracterizadas pela destruição seletiva de células b pancreáticas produtoras de insulina e do sistema nervoso central, respectivamente. Acredita-se que a desregulação da expressão de genes reguladores da maquinaria apoptótica possa contribuir para o desenvolvimento da auto-imunidade, visto que algumas dessas moléculas participam nos processos de tolerância central e periférica de linfócitos auto-reativos. O objetivo deste projeto foi analisar a expressão de moléculas reguladoras das vias intrínseca, extrínseca e da Família de proteínas inibidoras da apoptose (IAP) em 33 indivíduos saudáveis, 15 pacientes com DM-1 e 18 com EM submetidos à terapia de imunossupressão em altas doses seguida do transplante autólogo de células-tronco hematopoéticas (IAD/TACTH). As células mononucleares (CMN) foram isoladas do sangue periférico dos controles e de pacientes nos períodos pré-mobilização (pré-mob), pré-condicionamento (pré-cond), D+180, D+360, D+540 e D+720 pós-transplante. As CMN foram utilizadas para extração de RNA, síntese de cDNA, quantificação da expressão por PCR em tempo real dos genes a1, bcl-2, bcl-w, bcl-xL, mcl-1, bad, bak, bax, bid, bik, bim, bok, noxa, fas, fasL, c-FLIPL, cIAP-1 e cIAP-2 e protéica de Bcl-2, Bcl-xL, Bak, Bim e c-FLIPL por western-blotting. Os resultados de expressão gênica foram representados por unidades relativas de expressão em medianas nas diferentes amostras. Os pacientes com DM-1 apresentaram diminuição da expressão dos genes anti-apoptóticos bcl-2 (mediana: 0,98; p=0,04), bcl-w (0,08; p=0,04), mcl-1 (1254; p=0,03) e cIAP-1 (1,24; p=0,003) nas CMN dos pacientes no período pré-mob em relação aos indivíduos saudáveis (medianas: bcl-2: 7,58; bcl-w: 0,52; mcl-1: 1659; cIAP-1: 14,5), enquanto a expressão de cIAP-2 (60,8; p=0,0005) estava aumentada em relação aos controles (23,3). Foi observada redução significativa na expressão dos genes pró-apoptóticos bad (0,002; p<0,0001), bax (0,01; p=0,002) e fasL (1,66; p=0,001) no período pré-mob comparada aos controles sadios (bad: 0,23; bax: 2,79; fasL: 3,56). Os níveis de RNAm de bid (0,10; p=0,001) e bok (0,72; p=0,006) estavam elevados no pré-mob em relação ao grupo controle (bid: 0,004; bok: 0,31). As moléculas bcl-2, bcl-w, bcl-xL, mcl-1, bad, bax, bok, fasL e cIAP-1 atingiram níveis de RNAm similares aos controles após o TACTH. Foi verificado que a expressão de bcl-w, cIAP-1 e noxa estava maior nos pacientes com DM-1 em remissão quando comparados àqueles em recaída. A diminuição da expressão de a1, bcl-2 e bcl-w e o aumento de fas e noxa correlacionaram-se às porcentagens de hemoglobina glicosilada, concentração de auto-anticorpos GAD65, e aos níveis séricos de peptídeo-C após o transplante. Os pacientes com EM mostraram uma expressão reduzida dos genes anti-apoptóticos bcl-w (0,11; p=0,02) e cIAP-1 (1,87; p=0,04) no pré-mob comparada aos valores dos controles (bcl-w: 0,27; cIAP-1: 7,75) e maior expressão dos genes a1 (90,8; p=0,001) e cIAP-2 (58,8; p=0,009) em relação aos controles (a1: 12,7; cIAP-2: 22,3). As moléculas pró-apoptóticas bad (0,007; p=0,01) e bax (0,0007; p=0,004) mostraram menor expressão nas CMN no período pré-mob do que nos controles (bad: 0,27; bax: 1,24). Os genes bid (20,7; p=0,004), bik (0,84; p=0,02) e bok (1,77; p=0,0001) possuíam maior expressão no período pré-mob em relação aos indivíduos sadios (bid: 2,64; bik: 0,33; bok: 0,26). Não foram observadas diferenças significativas na expressão das moléculas da via extrínseca da apoptose nos pacientes com EM (p>0,05) nos períodos avaliados. Os valores de expressão de bcl-w, bak, bax, bik, bok e cIAP-1 atingiram níveis semelhantes aos controles após o transplante. A expressão dos genes bcl-2, cIAP-1, bad e bax estava maior nos pacientes em remissão da EM quando comparados àqueles em progressão neurológica. O aumento da expressão dos genes pró-apoptóticos bax, bak e bimEL correlacionou-se inversamente aos valores de EDSS dos pacientes com EM após o TACTH. Os resultados de expressão protéica foram equivalentes aos de expressão gênica nas duas doenças, com exceção dos dados das proteínas Bcl-2 e Bim. Em conjunto, os resultados demonstraram a desregulação da expressão de várias moléculas anti- e pró-apoptóticas nas CMN dos pacientes com DM-1 e EM. Esses achados sugerem a associação de alterações nos processos de apoptose celular com o surgimento e persistência de células auto-reativas no DM-1 e EM. Os dados indicam que essas alterações, principalmente a diminuição da expressão de moléculas pró-apoptóticas, como bak e bax, possam contribuir para a patogênese do DM-1 e EM. Além disso, a terapia de IAD/TACTH foi capaz de modular a expressão da maioria dos genes anormalmente expressos nas CMN dos pacientes com DM-1 e EM, já que esses atingiram níveis de expressão similares ao grupo controle após o transplante. Esta normalização da expressão de vários genes analisados correlacionou-se com a remissão clínica da doença na maioria dos pacientes / Type 1 diabetes mellitus (T1DM) and multiple sclerosis (MS) are inflammatory, organ-specific autoimmune diseases characterized by selective destruction of insulin-producing pancreatic -cells and central nervous system, respectively, by autoreactive B and T cells. Deregulation of apoptotic machinery is supposed to contribute to self-tolerance breakdown and autoimmune diseases pathogenesis, since apoptotic molecules have an important role in B and T lymphocytes central and peripheral tolerance mechanisms. The aim of this study was to evaluate the expression of pro and anti-apoptotic molecules from intrinsic and extrinsic apoptotic pathways and IAP Family members in 33 healthy individuals, 15 T1DM and 18 MS patients submitted to high-dose immunossupression therapy followed by autologous hematopoietic stem cell transplantation (HDI/AHSCT). Peripheral blood mononuclear cells (PBMC) were isolated from controls and patients at pre-mobilization (pre-mob), pre-conditioning (pre-cond), D+180, D+360, D+540 and D+720 post-transplantation. PBMC were used for RNA extraction, cDNA synthesis, gene quantification of a1, bcl-2, bcl-w, bcl-xL, bad, bak, bax, bid, bik, bimEL, bok, noxa, fas, fasL, c-FLIPL, cIAP-1 and cIAP-2 by Real Time PCR and Bcl-2, Bcl-xL, Bak, BimEL and c-FLIPL proteins detection by western-blotting. Results are expressed as median of relative expression units. Results from T1DM patients indicated that antiapoptotic molecules bcl-2 (median: 0,98; p=0,04), bcl-w (0,08; p=0,04), mcl-1 (1254; p=0,03) and cIAP-1 (1,24; p=0,003) were downregulated at pre-mob compared with healthy controls (medians bcl-2: 7,58; bcl-w: 0,52; mcl-1: 1659; cIAP-1: 14,5), while cIAP-2 (60,8; p=0,0005) gene expression was upregulated compared to healthy controls (23,3). We observed a significant decrease in proapoptotic bad (0,002; p<0,0001), bax (0,01; p=0,002) and fasL (1,66; p=0,001) genes expression in patients PBMC at pre-mob period compared to healthy subjects (bad: 0,23; bax: 2,79; fasL: 3,56). mRNA levels of bid (0.10; p=0.001) and bok (0.72; p=0.006) were elevated at pre-mob period when compared to control group (bid: 0.004; bok: 0.31). The bcl-2, bcl-w, bcl-xL, mcl-1, bad, bak, bax, bok, fasL and cIAP-1 mRNA levels reached controls levels after HDI/AHSCT. We observed that bcl-w, cIAP-1 and noxa gene expression were increased in T1DM patients in remission when compared to relapsed patients. The decreased antiapoptotic gene expression and increased in proapoptotic molecules correlated with decreased glicosilated hemoglobin percentages (Hb A1C) and anti-GAD65 antibodies and increased peptide-C levels. Results from MS patients showed decreased bcl-w (0,11; p=0,02) and cIAP-1 gene expression (1,87; p=0,04) in patients PBMC at pre-mob period compared to healthy controls (bcl-w: 0,27; cIAP-1: 7,75) and increased expression of a1 (90,8; p=0,001) and cIAP-2 (58,8; p=0,009) compared to controls (a1: 12,7; cIAP-2: 22,3). Proapoptotic molecules bad (0.007; p=0.01) and bax (0.0007; p=0.004) showed decreased gene expression at pre-mob compared to control group (bad: 0.27; bax: 1.24). bid (20.7; p=0.004), bik (0.84; p=0.01) and bok genes (1.77; p=0.0001) showed increased expression at pre-mob compared to healthy controls (bid: 2.64; bik: 0.33; bok: 0.26). Significant differences were not observed in the expression of the extrinsic pathway genes in pre-mob and healthy controls samples (p>0.05). bcl-w, bak, bax, bik, bok and cIAP-1 expression values reached healthy control values after transplantation. We observed that bcl-2, cIAP-1, bad and bax gene expression was increased in MS patients in disease remission when compared to patients with neurologic progression. Significant correlation of increased proapoptotic genes expression with decreased EDSS values in MS patients after HDI/AHSCT was observed. Results of protein quantification of apoptotic molecules in PBMC of T1DM and MS patients were similar to the gene expression results of these molecules, except for Bcl-2 and Bim proteins. Taken together, these data indicate a deregulated expression of anti- and proapoptotic genes in T1DM and MS patients PBMC. These data suggest an association of deregulated apoptosis with emergence and maintenance of autoreactive lymphocytes in analyzed patients. Based on these results, we suggest that this altered gene expression profile, mainly the decreased proapoptotic genes expression, as bak and bax, may contribute to T1DM and MS pathogenesis. Furthermore, we showed that the HDI/AHSCT therapy was able to modulate and normalize the expression of most genes abnormally expressed in T1DM and MS patients at pre-transplant period. Many analyzed genes achieved expression levels similar to healthy controls. The normalization of the expression of many evaluated genes correlated to disease remission in the majority of the patients.