Current immune suppressive strategies fail to induce donor-recipient immune tolerance after allogeneic hematopoietic cell transplantation. Accordingly, patients suffer morbidity and mortality from graft vs. host disease (GVHD) and prolonged immune suppressive therapy. Biologic insight into transplantation tolerance is needed, and translation of such insight to novel clinical strategies may improve clinical outcomes. We report original investigation at seminal phases of this process including initial prophylactic immune suppression, onset of acute graft vs. host disease, and ultimate immune suppression discontinuation: In a controlled randomized clinical trial, we demonstrate that sirolimus-based immune suppression reduces risk for acute GVHD, ameliorates the severity of subsequent chronic GVHD, and supports reconstitution of functional regulatory T cells. Study of tissue-infiltrating CD4+ T cell subsets in acute GVHD target organs supports a pathogenic role for Th17 cells. Finally, we demonstrate that peripheral blood transcriptional biomarkers provide mechanistic insight into human transplantation tolerance. These data signal progress, and suggest rational translational efforts to achieve transplantation tolerance.

Reproduction de : Mémoire du DES : Pharmacie hospitalière : Nantes : 2008. Reproduction de : Thèse d'exercice : Pharmacie : Nantes : 2008. / Bibliogr.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2009.

Techn. Universiẗat, Diss., 2005--München.

Submitted by CHRISTIANE AKEMI KOJIMA (christianekojima@yahoo.com.br) on 2016-04-26T01:07:31Z No. of bitstreams: 1 Transplante Idoso Eficacia FINAL 4.doc-4-2.pdf: 1554211 bytes, checksum: a54e7e2f51f5bb432e6541f5b4c32f4d (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-04-26T14:15:05Z (GMT) No. of bitstreams: 1 kojima_ca_me_bot.pdf: 1554211 bytes, checksum: a54e7e2f51f5bb432e6541f5b4c32f4d (MD5) / Made available in DSpace on 2016-04-26T14:15:05Z (GMT). No. of bitstreams: 1 kojima_ca_me_bot.pdf: 1554211 bytes, checksum: a54e7e2f51f5bb432e6541f5b4c32f4d (MD5) Previous issue date: 2016-03-04 / Introdução: O transplante renal é considerado uma opção de terapia renal substitutiva segura para pacientes acima de 60 anos, entretanto, não há consenso sobre o melhor esquema imunossupressor para o paciente transplantado renal idoso. Objetivo: Avaliar a eficácia e segurança da combinação de tacrolimus e sirolimus em doses reduzidas comparada com a associação tacrolimus e micofenolato. Métodos: Estudo prospectivo randomizado de centro único comparando a combinação de tacrolimus e sirolimus em dose reduzida (grupo sirolimus) contra tacrolimus e micofenolato (grupo micofenolato). Foram incluídos todos os pacientes transplantados renais maiores de 60 anos. Foram avaliadas a sobrevida do paciente e enxerto, taxas de rejeição, função renal e incidência de infecção por citomegalovírus (CMV) em 12 meses de seguimento. Resultados: Foram randomizados 46 pacientes e analisados 44 casos (dois casos excluídos por não terem sido transplantados). As características basais dos grupos foram semelhantes sendo todos os casos transplantados com doador falecido e a maioria induzida com basiliximabe. O grupo micofenolato (n=23) e o grupo sirolimus (n=21) apresentaram sobrevida do paciente e enxerto censurado óbito respectivamente de 95,7% e 100% para o micofenolato e 79,6% e 90,5% para o sirolimus sem diferenças estatísticas. A incidência de rejeição e função renal ao longo de 12 meses foi semelhante entre os grupos. A infecção de ferida operatória, retardo de função do enxerto e proteinúria foram semelhantes entre os grupos. O colesterol total e HDL colesterol foram maiores no grupo sirolimus. A infecção por CMV ocorreu em 60,9% no grupo micofenolato e 16,7% no grupo sirolimus apresentando um risco relativo 3,54 [1,2 – 10,3] vezes maior no grupo micofenolato, p=0,004. Conclusão: No grupo de transplantados renais idosos a combinação de tacrolimus e sirolimus em doses reduzidas foi segura mantendo taxas semelhantes de função renal em 12 meses, rejeição e sobrevida do enxerto e paciente. As principais complicações associadas ao sirolimus foram semelhantes com exceção de maiores taxas de colesterol total. A incidência de CMV foi significativamente menor no grupo sirolimus. / Introduction: Renal transplantation is considered safe for patients over 60 years, however, there is no consensus on the best immunosuppressive regimen in elderly. Objective: To evaluate the combination of tacrolimus and sirolimus in reduced dose in renal function comparing the combination tacrolimus and mycophenolate. Methods: A single-center prospective randomized study comparing the combination of tacrolimus and sirolimus in reduced dose (sirolimus group) against tacrolimus and mycophenolate (mycophenolate group). We included all kidney transplant patients over 60 years of age. We evaluated patient survival, biopsy prove acute rejection, renal function and incidence of cytomegalovirus (CMV) at 12 months of follow-up. Results: 46 patients were randomized and we analyzed 44 cases (two cases excluded because they were not transplanted). Baseline characteristics were similar between groups, all patients were transplanted with deceased donor, and the majority were induced with basiliximab. Mycophenolate group (n = 23) and sirolimus group (n = 21) had patient survival, and death censored graft survival respectively 95.7% and 100% for mycophenolate and 79.6% and 90.5% for the sirolimus without statistical differences. The incidence of acute rejection and kidney function over 12 months was similar between the groups. Infection of the surgical wound, delayed graft function and proteinuria were similar between groups. The total cholesterol and HDL cholesterol were higher in the sirolimus group. CMV infection occurred in 60.9% and 16.7% in mycophenolate and sirolimus group respectively. The relative risk of CMV were 3.54 [1, 2 - 10.3] times greater in mycophenolate group, p=0.004. Conclusion: In the sample of elderly kidney transplant combining tacrolimus and sirolimus in low doses was safe keeping similar rates of renal function at 12 months, rejection and graft survival. The main complications associated with sirolimus were similar except for a higher total cholesterol rates. The incidence of CMV was significantly lower in the sirolimus group.

Abnormal thyroid cell proliferation causes human diseases, such as goiter, thyroid adenoma or carcinoma and primary hypothyroidism resulting from hypoplasia. Thyrotropin (TSH), mainly acting through cAMP and cAMP-dependent protein kinases (PKA), is considered the main regulator of thyrocyte proliferation and differentiation. The general aim of this thesis was to get new mechanistic insights in the regulatory action of the cAMP pathway on various functions of thyrocytes, including proliferation.<p><p>During the first part of this thesis work, we have collaborated to a study of the effects of the TSH/cAMP pathway on small G proteins of the Rho family and their impact on the actin cytoskeleton and thyroid cell function. This study, performed in canine thyrocytes, showed for the first time, that the TSH/cAMP/PKA pathway inactivates the three small G proteins RhoA, Rac1 and Cdc42 and the RhoA/ROCK/LIMK/cofilin pathway. Inactivation of the latter appeared both necessary and sufficient to mediate the action of TSH and PKA on the reorganization of actin microfilaments and its morphological impact. Moreover, this inactivation by PKA of Rho-mediated actin polymerization also played an important role in the cAMP-dependent expression of thyroid differentiation genes. On the other hand, a residual RhoA activity appeared to be required for mitogenesis. This dependence of DNA synthesis on RhoA activity was not mediated by ROCK-dependent events nor by the integrity of the actin cytoskeleton. Indeed, DNA synthesis induction was unexpectedly resistant to actin depolymerisation in canine thyrocytes, which explains how it could be compatible with the cAMP-dependent microfilament disruption. <p><p>This first study did not provide new insights on how the cAMP/PKA-dependent mitogenic stimulus can trigger cell cycle progression, which, in thyrocytes, depends on the phosphorylation of pRb by the cyclin D3-CDK4 complex. In the various in vitro thyroid models, the only convergent early signaling event found in response to TSH/cAMP, insulin and growth factors was the phosphorylation and activation of p70 S6K1 which largely depends on mTOR (mammalian Target Of Rapamycin). The main part of the work in this thesis has been devoted to investigation of the action of TSH/cAMP on the mTOR pathway. mTOR is a therapeutic target for a wide variety proliferative disorders and rapamycin derivates are now considered in anti-cancer treatments.<p><p>We have shown for the first time in PC Cl3 rat thyroid cells that TSH, through cAMP, activates mTORC1, leading to phosphorylation of S6K1 and 4E-BP1. mTORC1-dependent S6K1 phosphorylation in response to both insulin and cAMP required amino acids, whereas inhibition of AMPK and GSK3 enhanced insulin but not cAMP effects. Unlike insulin, TSH/cAMP did not activate PKB, nor induce TSC2 phosphorylation at Thr1462 and Tyr1571. However, like insulin, TSH/cAMP produced a stable increase in mTORC1 kinase activity associated with augmented 4E-BP1 binding to raptor. This could be caused in part by Thr246-phosphorylation of PRAS40, which was found as an in vitro substrate of PKA, but other regulatory events likely remain to be uncovered. Both in PC Cl3 cells and primary dog thyrocytes, rapamycin inhibited DNA synthesis and pRb phosphorylation induced by TSH and insulin. Rapamycin reduced cyclin D3 accumulation but not the abundance of cyclin D3-CDK4 complexes. However, rapamycin inhibited the activity of these complexes and the activating Thr172-phosphorylation of CDK4 stimulated by both TSH and insulin. We propose that mTORC1 activation by TSH, at least in part through PKA-dependent phosphorylation of PRAS40, crucially contributes to mediate cAMP-dependent mitogenesis by regulating CDK4 Thr172-phosphorylation. / Doctorat en Sciences biomédicales et pharmaceutiques / info:eu-repo/semantics/nonPublished

Orientador: Luis Gustavo Modelli de Andrade / Resumo: Introdução: O transplante renal é considerado uma opção de terapia renal substitutiva segura para pacientes acima de 60 anos, entretanto, não há consenso sobre o melhor esquema imunossupressor para o paciente transplantado renal idoso. Objetivo: Avaliar a eficácia e segurança da combinação de tacrolimus e sirolimus em doses reduzidas comparada com a associação tacrolimus e micofenolato. Métodos: Estudo prospectivo randomizado de centro único comparando a combinação de tacrolimus e sirolimus em dose reduzida (grupo sirolimus) contra tacrolimus e micofenolato (grupo micofenolato). Foram incluídos todos os pacientes transplantados renais maiores de 60 anos. Foram avaliadas a sobrevida do paciente e enxerto, taxas de rejeição, função renal e incidência de infecção por citomegalovírus (CMV) em 12 meses de seguimento. Resultados: Foram randomizados 46 pacientes e analisados 44 casos (dois casos excluídos por não terem sido transplantados). As características basais dos grupos foram semelhantes sendo todos os casos transplantados com doador falecido e a maioria induzida com basiliximabe. O grupo micofenolato (n=23) e o grupo sirolimus (n=21) apresentaram sobrevida do paciente e enxerto censurado óbito respectivamente de 95,7% e 100% para o micofenolato e 79,6% e 90,5% para o sirolimus sem diferenças estatísticas. A incidência de rejeição e função renal ao longo de 12 meses foi semelhante entre os grupos. A infecção de ferida operatória, retardo de função do enxerto e proteinúria for... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Introduction: Renal transplantation is considered safe for patients over 60 years, however, there is no consensus on the best immunosuppressive regimen in elderly. Objective: To evaluate the combination of tacrolimus and sirolimus in reduced dose in renal function comparing the combination tacrolimus and mycophenolate. Methods: A single-center prospective randomized study comparing the combination of tacrolimus and sirolimus in reduced dose (sirolimus group) against tacrolimus and mycophenolate (mycophenolate group). We included all kidney transplant patients over 60 years of age. We evaluated patient survival, biopsy prove acute rejection, renal function and incidence of cytomegalovirus (CMV) at 12 months of follow-up. Results: 46 patients were randomized and we analyzed 44 cases (two cases excluded because they were not transplanted). Baseline characteristics were similar between groups, all patients were transplanted with deceased donor, and the majority were induced with basiliximab. Mycophenolate group (n = 23) and sirolimus group (n = 21) had patient survival, and death censored graft survival respectively 95.7% and 100% for mycophenolate and 79.6% and 90.5% for the sirolimus without statistical differences. The incidence of acute rejection and kidney function over 12 months was similar between the groups. Infection of the surgical wound, delayed graft function and proteinuria were similar between groups. The total cholesterol and HDL cholesterol were higher in the siro... (Complete abstract click electronic access below) / Mestre

Le complexe 1 de la Ser/Thr kinase mTOR (mammalian Target Of Rapamycin) (mTORC1), son médiateur en aval, S6K1, (p70 S6 kinase) et RSK (p90 ribosomal S6 kinase) sont des régulateurs clés de la signalisation de l’insuline et du métabolisme énergétique. La voie mTORC1/S6K contrôle la prolifération, la croissance cellulaire, la synthèse protéique, la lipogenèse, la biogenèse mitochondriale et inhibe l’autophagie. L’une des particularités importantes de cette voie de signalisation est l’intégration de différents signaux tels les facteurs de croissance, le statut énergétique, l’oxygène et les nutriments. Ainsi, la voie mTORC1/S6K1 est suractivée par l’excès de nutriments et ses kinases sont bien connues pour être suractivées dans l'obésité. De plus, RSK est une kinase en aval de la voie des MAPK (mitogen-activated protein kinase) et est connue pour réguler la prolifération, la croissance cellulaire et activer la voie mTORC1. Parmi les activateurs de RSK, on retrouve l’insuline et l’hyperglycémie. Ainsi, mTORC1/S6K1 et RSK sont impliquées dans le développement de la résistance à l’insuline, de l’obésité et du diabète de type 2. Dans une première étude publiée dans la revue Diabetologia, nous avons évalué l’impact de l’inhibition pharmacologique de S6K1 par le PF-4708671 sur la résistance à l’insuline et le métabolisme énergétique. Pour ce faire, nous avons utilisé des myotubes (L6) et des hépatocytes (FAO) en culture et montrés que l’inhibition de S6K1 augmente le captage de glucose musculaire et diminue la production hépatique de glucose. Par la suite, nous avons utilisé un modèle de souris obèse induit par une diète riche en gras afin d’évaluer le potentiel thérapeutique de l’inhibition pharmacologique de S6K1. Ces études nous ont permis de montrer que l’utilisation d’un inhibiteur pharmacologique de S6K1 améliore la tolérance au glucose et la phosphorylation d’Akt. Mécanistiquement, nous avons démontré dans un 2ième temps que le PF inhibe non seulement l’activité de S6K1, mais inhibe aussi l’activité du complexe I mitochondrial causant une augmentation de l’activité de l’AMPK (AMP activated protein kinase) et une inhibition de l’ACC (acetyl-CoA carboxylase). Parallèlement, nous avons montré dans une 3e étude, publiée dans J. Biol. Chem., que l'inhibition de RSK1 par l’inhibiteur pharmacologique (BI-D1870) ou d’un mutant RSK1 dominant négatif (DN-RSK1), diminue la phosphorylation d’IRS-1 sur la S1101. Par ailleurs, l’expression du DN-RSK1 augmente l’action de l’insuline sur le transport du glucose musculaire et la production de glucose hépatique. Ainsi, nous avons montré que RSK1 est un nouveau régulateur de la signalisation de l’insuline en phosphorylant la S1101 d’IRS-1. Nous proposons ainsi que l’inhibition de S6K1 et de RSK1 sont des approches thérapeutiques potentielles afin de traiter la résistance à l’insuline et le diabète de type 2. Mots clés : mTORC1, S6K1, RSK, MAPK, résistance à l’insuline, obésité, PF-4708671 / The Ser/Thr kinase mTOR complex 1 (mammalian Target Of Rapamycin) (mTORC1), his downstream effectors S6K1 (p70 ribosomal S6 kinase) and RSK (p90 ribosomal S6 kinase) are key regulators of insulin signaling and energy metabolism. The mTORC1/S6K1 pathway regulates cellular proliferation, growth, protein synthesis, lipogenesis, mitochondrial biogenesis, insulin signaling and inhibits autophagy. One of the most important roles of this signaling pathway is to integrate differents signals such as growth factors, energy status, oxygen, and nutrients. Thus, the mTORC1/S6K1 pathway is overactivated by nutrient excess conditions such as obesity. In addition, RSK is a downstream kinase of MAPK (mitogen-activated protein kinase) and it is also known to regulates cell proliferation, growth and to activate the mTORC1 pathway. Insulin and hyperglycemia are known to be among RSK activators. Therefore, mTORC1/S6K1 and RSK are involved in insulin resistance, obesity and type 2 diabetes. In a first study published in Diabetologia journal, we evaluated the effect of S6K1 inhibition with a selective S6K1 inhibitor, PF-4708671, on insulin resistance and energy metabolism. We used myotubes (L6) and hepatocytes (FAO) and observed that S6K1 inhibition increases glucose uptake in muscle and decrease glucose production in hepatocytes. In both cell type, S6K1 inhibition increases insulin-stimulating Akt phosphorylation. In addition, we treated obese mice fed high-fat diet for 1-week with S6K1 inhibitor. Mice treated with PF-4708671 have improved glucose tolerance and insulin-stimulating Akt phosphorylation in muscle, adipose tissue, and liver compared to obese mice treated with vehicle. Mechanistically, we showed in a 2nd study that this inhibitor inhibits S6K1 activity but also mitochondrial complex 1 which is associated with an increase in AMPK activation. Along with this study, we showed in a 3rd study published in J. Biol. Chem., that RSK1 phosphorylates directly IRS-1 on Ser1101 and RSK inhibition, by using either a RSK inhibitor (BI-D1870) or dominant-negative RSK1, improves insulin stimulating Akt phosphorylation as well as increasing glucose uptake in myotubes and inhibiting hepatic glucose production in vitro. Therefore, we demonstrated that RSK is a novel regulator of insulin signaling by phosphorylation Ser1101 of IRS-1. In conclusion, we are proposing that S6K1 inhibition and RSK1 inhibition are potential therapeutics targets to treat insulin resistance and type 2 diabetes. Keywords : mTORC1, S6K1, RSK, MAPK, insulin resistance, obesity, PF-470867

No description available.

La voie de signalisation mTORCl/S6Kl est impliquée dans le développement de la résistance à l'insuline associée à l'obésité en exerçant une boucle de rétro-contrôle négative sur la voie de signalisation PI3K-Akt. Tandis que l'utilisation à court terme de la rapamycine, l'inhibiteur pharmacologique de la voie mTORCl, permet d'inhiber le rétro-contrôle négatif, les effets de l'inhibition chronique de la voie sur le métabolisme ne sont pas connus. L'objectif principal des études présentées dans cette thèse était d'investiguer les effets métaboliques de l'inhibition chronique de la voie de signalisation mTORCl/S6Kl in vitro et in vivo. Dans la première étude, nous avons montré que l'inhibition chronique de mTORCl/S6Kl découple l'activation d'Akt de la PI3K ce qui cause une résistance à l'insuline dans les cellules 3T3-L1. Dans une deuxième étude, nous avons découvert que l'utilisation chronique de la rapamycine in vivo cause une intolérance au glucose et une résistance à l'insuline de par une augmentation de la gluconéogénèse hépatique en plus d'affecter négativement le métabolisme des lipides. Dans une troisième étude, nous avons démontré que l'inhibition chronique de mTORCl/S6K1 dans les cellules hépatique FAO découple l'activation d'Akt de la PI3K ce qui augmente la production de glucose hépatique. Finalement, dans une quatrième étude, nous avons déterminé que l'inhibition chronique de mTORCl/S6K1 dans les cellules L6 ne permet pas de restaurer le transport du glucose stimulé par l'insuline en présence d'un excès de nutriments. L'ensemble de nos études démontre le rôle important joué par la voie de signalisation mTORCl/S6K1 sur le contrôle du métabolisme du glucose et des lipides et limite l'inhibition chronique de mTOR comme cible thérapeutique pour le traitement du diabète de type 2 et de l'obésité.