RESUMO
Alzheimer's disease (AD) is one of the most common neurodegenerative diseases. Although many researchers have attempted to explain the origins of AD, developing an effective strategy in AD clinical therapy is difficult. Recent studies have revealed a potential link between AD and circRNA-associated-ceRNA networks. However, few genome-wide studies have identified the potential circRNA-associated-ceRNA pairs involved in AD. In this study, we systematically explored the circRNA-associated-ceRNA mechanism in a 7-month-old senescence-accelerated mouse prone 8 (SAMP8) model brain through deep RNA sequencing. We obtained 235 significantly dysregulated circRNA transcripts, 30 significantly dysregulated miRNAs, and 1,202 significantly dysregulated mRNAs. We then constructed the most comprehensive circRNA-associated-ceRNA networks in SAMP8 brain. GO analysis revealed that these networks were involved in regulating the development of AD from various angles, for instance, axon terminus (GO: 0043679) and synapse (GO: 0045202). Following rigorous selection, we discovered that the circRNA-associated-ceRNA networks in this AD mouse model were mainly involved in the regulation of Aß clearance (Hmgb2) and myelin function (Dio2). This research is the first to provide a systematic dissection of circRNA-associated-ceRNA profiling in SAMP8 mouse brain. The selected circRNA-associated-ceRNA networks can profoundly affect the diagnosis and therapy of AD in the future.
Assuntos
Encéfalo/metabolismo , Interferência de RNA , RNA/genética , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Animais , Encéfalo/fisiopatologia , Análise por Conglomerados , Biologia Computacional/métodos , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Ontologia Genética , Redes Reguladoras de Genes , Estudos de Associação Genética , Aprendizagem em Labirinto , Memória , Camundongos , Camundongos Transgênicos , MicroRNAs/genética , RNA Circular , RNA Mensageiro/genéticaRESUMO
BACKGROUND: Immunoglobulin-cytokine fusion molecules have been shown to be the new generation of immunomodulating agents in transplantation tolerance induction. In the present study, we tested whether immunoregulatory cytokine fusion proteins of IL-10/Fc, TGF-ß/Fc, or IL-2/Fc would enhance allogeneic bone marrow cell (BMC) engraftment and promote tolerance induction. METHODS: B6 (H2) mice were conditioned with anti-CD154 (MR1) and rapamycin (Rapa) plus 100 cGy total body irradiation (MR1/Rapa/100 cGy) and transplanted with allogeneic B10.D2 (H2) BMC. Recipients were treated with lytic IL-2/Fc, nonlytic IL-2/Fc, TGF-ß/Fc, or IL-10/Fc fusion proteins to promote chimerism to induce tolerance. RESULTS: Donor chimerism was achieved in 20% of recipients conditioned with MR1/Rapa/100 cGy. The addition of TGF-ß/Fc (5- or 10-day treatment) or nonlytic IL-2/Fc (10-day treatment) fusion proteins to the conditioning resulted in engraftment in nearly 100% of recipients. In contrast, lytic IL-2/Fc or IL-10/Fc had no effect. The combination of nonlytic IL-2/Fc and TGF-ß/Fc had a synergistic effect to promote engraftment and resulted in significantly higher donor chimerism compared with recipients conditioned with TGF-ß/MR1/Rapa/100 cGy. Engraftment was durable in the majority of chimeras and increased over time. The chimeras accepted donor skin grafts and promptly rejected third-party skin grafts. Moreover, specific T cell receptor-Vß5.½ and TCR-Vß11 clonal deletion was detected in host T cells in chimeras, suggesting central tolerance to donor alloantigens. CONCLUSIONS: Allogeneic BMC engraftment is enhanced with TGF-ß/Fc fusion protein treatment. TGF-ß/Fc and nonlytic IL-2/Fc exert a synergistic effect in promotion of alloengraftment and donor-specific transplant tolerance, significantly decreasing the minimum total body irradiation dose required.
Assuntos
Transplante de Medula Óssea , Rejeição de Enxerto/prevenção & controle , Sobrevivência de Enxerto/efeitos dos fármacos , Fragmentos Fc das Imunoglobulinas/farmacologia , Imunossupressores/farmacologia , Interleucina-2/farmacologia , Transplante de Pele , Fator de Crescimento Transformador beta/farmacologia , Quimeras de Transplante , Condicionamento Pré-Transplante/métodos , Tolerância ao Transplante/efeitos dos fármacos , Animais , Transplante de Medula Óssea/efeitos adversos , Células Cultivadas , Técnicas de Cocultura , Genes Codificadores da Cadeia beta de Receptores de Linfócitos T/imunologia , Rejeição de Enxerto/imunologia , Isoantígenos/imunologia , Camundongos Endogâmicos C57BL , Modelos Animais , Proteínas Recombinantes de Fusão/farmacologia , Sirolimo/farmacologia , Transplante de Pele/efeitos adversos , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Fatores de Tempo , Transplante Homólogo , Irradiação Corporal TotalRESUMO
BACKGROUND: Cellular therapies for immunomodulation in vascularized composite allotransplantation (VCA) have gained importance due to their potential for minimization of immunosuppression. Adipose-derived (AD) mesenchymal stem cells (MSCs) especially have shown encouraging potential. We investigated the influence of timing and frequency of AD-MSC treatment on immunologic and graft survival as well as graft vasculopathy outcomes after VCA. METHODS: Lewis rats received full-mismatched Brown Norway rat hindlimb transplants. Recipient animals were assigned to groups receiving donor-derived AD-MSCs (10 cells/animal) either on postoperative day (POD) 1, POD 4, or repeatedly on POD 4, 8, and 15, and compared to untreated controls. RESULTS: Although AD-MSC administration on POD 1 or POD 4, 8, and 15 resulted in 50% long-term graft acceptance, recipients treated on POD 4, and controls rejected before POD 50. All treated animals revealed peripheral blood chimerism (4 weeks), most pronounced after repetitive cell administration (12.92% vs 5.03% [POD 1] vs 6.31% [POD 4]; P < 0.05; all P < 0.01 vs control 1.45%). Chimerism was associated with the generation of regulatory T cells (CD4CD25FoxP3). In vitro mixed lymphocyte reactions revealed modulation of the recipient immune response after AD-MSC treatment. Graft arteries at end point revealed significant differences of arterial intimal thickness between rejecting and AD-MSC-treated animals (P < 0.01). CONCLUSIONS: Taken together, our results point to the potential for repetitive AD-MSC administration in improving outcomes after VCA. Future studies are warranted into optimization of the dosing and frequency of AD-MSC therapy, either alone or used in, combination with other cell therapies (such as hematopoietic stem cells or bone marrow-derived MSC or dendritic cells) for optimization of appropriate conditioning or maintenance regimens.
Assuntos
Tecido Adiposo/citologia , Aloenxertos Compostos/irrigação sanguínea , Aloenxertos Compostos/transplante , Sobrevivência de Enxerto , Membro Posterior/irrigação sanguínea , Membro Posterior/transplante , Imunoterapia/métodos , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/imunologia , Alotransplante de Tecidos Compostos Vascularizados/métodos , Animais , Proliferação de Células , Células Cultivadas , Aloenxertos Compostos/imunologia , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/prevenção & controle , Membro Posterior/imunologia , Imunoterapia/efeitos adversos , Ativação Linfocitária , Masculino , Transplante de Células-Tronco Mesenquimais/efeitos adversos , Modelos Animais , Ratos Endogâmicos BN , Ratos Endogâmicos Lew , Linfócitos T Reguladores/imunologia , Fatores de Tempo , Quimeras de Transplante , Tolerância ao Transplante , Doenças Vasculares/imunologia , Doenças Vasculares/prevenção & controle , Alotransplante de Tecidos Compostos Vascularizados/efeitos adversosRESUMO
Pancreatic islet transplantation (PIT) represents a potential therapy to circumvent the need for exogenous insulin in type 1 diabetes. However, PIT remains limited by lack of donor islets and the need for long-term multidrug immunosuppression to prevent alloimmune islet rejection. Our goal was to evaluate a local immunoregulatory strategy that sustains islet allograft survival and restores glucose homeostasis in the absence of systemic immunosuppression. Nanogram quantities of murine CTLA4/Fc fusion protein were controllably delivered within human acellular dermal matrix scaffolds using an inkjet-based biopatterning technology and cotransplanted with allogeneic islets under the renal capsule to create an immunoregulatory microenvironment around the islet allograft. We achieved long-term engraftment of small loads of allogeneic islet cells with 40% of MHC-mismatched mouse recipients maintaining sustained normoglycemia following pancreatic ß-cell ablation by streptozotocin. Biopatterned CTLA4/Fc local therapy was associated with expansion of Foxp3+ regulatory T cells and shifts in cytokine production and gene expression from proinflammatory to regulatory profiles, thus substantially benefiting islet allografts survival and function. This study is a new paradigm for targeted therapies in PIT that demonstrates the favorable effects of immune alterations in the transplant milieu and suggests a unique strategy for minimizing systemic immunosuppression and promoting islet allograft survival.
Assuntos
Abatacepte/metabolismo , Glucose/metabolismo , Transplante das Ilhotas Pancreáticas , Animais , Células Cultivadas , Citocinas/metabolismo , Sobrevivência de Enxerto/imunologia , Sobrevivência de Enxerto/fisiologia , Homeostase/imunologia , Homeostase/fisiologia , Imunomodulação/imunologia , Imunomodulação/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Subpopulações de Linfócitos T/metabolismo , Linfócitos T Reguladores/metabolismoRESUMO
BACKGROUND: Strategies aiming at minimization or elimination of systemic immunosuppression are key immediate goals for clinical expansion of vascularized composite allotransplantation (VCA). We compared the in vitro and in vivo immunomodulatory efficacy of adipose-derived mesenchymal stem cells (AD-MSCs) and bone marrow (BM)-derived MSCs in a rat VCA model. METHODS: Both cell types were tested in vitro for suppressor function using mixed lymphocyte reactivity assays. AD-MSCs or BM-MSCs were administered intravenously (1 × 10 or 5 × 10 cells/animal) to Lewis rat recipients of mismatched Brown Norway hindlimb transplants. Short course tacrolimus (FK-506) monotherapy was withdrawn at postoperative day 21. In vivo regulatory T-cell induction, peripheral blood chimerism, and microchimerism in lymphatic organs were analyzed. RESULTS: AD-MSCs and BM-MSCs exhibited strong dose-dependent suppressor function in vitro, which was significantly more pronounced for AD cells. In vivo, all animals revealed peripheral multi-lineage chimerism at four weeks (P < 0.01) independent of cell type and dosage. Regulatory T-cell levels were increased with both cell types, the most in AD-MSC groups. These immunomodulatory effects were only transient. MSC treatment resulted in long-term (>120 day) allograft survival in 47% of the animals, which correlated with durable microchimerism in BM and spleen. CONCLUSIONS: AD-MSCs and BM-MSCs exert immunomodulatory effects that prolong survival of immunogenic skin-bearing VCA grafts with short course (21 day) tacrolimus induction therapy. The in vivo findings in terms of allograft survival did not reflect superior immunomodulatory characteristics of AD-MSCs found in vitro.