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BACKGROUND: PCSK9 (proprotein convertase subtilisin/kexin 9), which is mainly secreted by the liver, is not only a therapeutic target for hyperlipidemia and cardiovascular disease, but also has been implicated in the immune regulation of infections and tumors. However, the role of PCSK9 and the liver in heart transplant rejection (HTR) and the underlying mechanisms remain unclear. METHODS: We assessed serum PCSK9 expression in both murine and human recipients during HTR and investigated the effect of PCSK9 ablation on HTR by using global knockout mice and a neutralizing antibody. Moreover, we performed multiorgan histological and transcriptome analyses, and multiomics and single-cell RNA-sequencing studies of the liver during HTR, as well. We further used hepatocyte-specific Pcsk9 knockout mice to investigate whether the liver regulated HTR through PCSK9. Last, we explored the regulatory effect of the PCSK9/CD36 pathway on the phenotype and function of macrophages in vitro and in vivo. RESULTS: Here, we report that murine and human recipients have high serum PCSK9 levels during HTR. PCSK9 ablation prolonged cardiac allograft survival and attenuated the infiltration of inflammatory cells in the graft and the expansion of alloreactive T cells in the spleen. Next, we demonstrated that PCSK9 was mainly produced and significantly upregulated in the recipient liver, which also showed a series of signaling changes, including changes in the TNF-α (tumor necrosis factor α) and IFN-γ (interferon γ) signaling pathways and the bile acid and fatty acid metabolism pathways. We found mechanistically that TNF-α and IFN-γ synergistically promoted PCSK9 expression in hepatocytes through the transcription factor SREBP2 (sterol regulatory element binding protein 2). Moreover, in vitro and in vivo studies indicated that PCSK9 inhibited CD36 expression and fatty acid uptake by macrophages and strengthened the proinflammatory phenotype, which facilitated their ability to promote proliferation and IFN-γ production by donor-reactive T cells. Last, we found that the protective effect of PCSK9 ablation against HTR is dependent on the CD36 pathway in the recipient. CONCLUSIONS: This study reveals a novel mechanism for immune regulation by the liver through the PCSK9/CD36 pathway during HTR, which influences the phenotype and function of macrophages and suggests that the modulation of this pathway may be a potential therapeutic target to prevent HTR.
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Transplante de Coração , Pró-Proteína Convertase 9 , Humanos , Camundongos , Animais , Pró-Proteína Convertase 9/genética , Pró-Proteína Convertase 9/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Células Hep G2 , Fígado/metabolismo , Ácidos Graxos/metabolismo , Camundongos Knockout , Transplante de Coração/efeitos adversos , Receptores de LDL/genéticaRESUMO
Thoracic aortic aneurysm (TAA), a serious cardiovascular disease that causes morbidity and mortality worldwide. At present, few biomarkers can accurately diagnose the appearance of TAA before dissection or rupture. Our research has the intention to investigate the developing applicable biomarkers for TAA promising clinically diagnostic biomarkers or probable regulatory targets for TAA. In our research, we built correlation networks utilizing the expression profile of peripheral blood mononuclear cell obtained from a public microarray data set (GSE9106). Furthermore, we chose the turquoise module, which has the strongest significance with TAA and was further analyzed. Fourteen genes that overlapped with differentially expressed proteins in the medial aortic layer were obtained. Subsequently, we verified the results applying quantitative polymerase chain reaction (Q-PCR) to our clinical specimen. In general, the Q-PCR results coincide with the majority of the expression profile. Fascinatingly, a notable change occurred in CLU, DES, MYH10, and FBLN5. In summary, using weighted gene coexpression analysis, our study indicates that CLU, DES, MYH10, and FBLN5 were identified and validated to be related to TAA and might be candidate biomarkers or therapeutic targets for TAA.
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Aneurisma da Aorta Torácica/sangue , Clusterina/sangue , Desmina/sangue , Proteínas da Matriz Extracelular/sangue , Cadeias Pesadas de Miosina/sangue , Miosina não Muscular Tipo IIB/sangue , Aneurisma da Aorta Torácica/genética , Aneurisma da Aorta Torácica/patologia , Biomarcadores/sangue , Proteínas da Matriz Extracelular/genética , Feminino , Perfilação da Expressão Gênica/métodos , Humanos , Leucócitos Mononucleares/metabolismo , Masculino , Pessoa de Meia-Idade , Transcriptoma/genéticaRESUMO
BACKGROUND: Emerging evidence has highlighted the role of macrophages in heart transplant rejection (HTR). However, the molecular signals modulating the immunometabolic phenotype of allograft-infiltrating macrophages (AIMs) during HTR remain unknown. METHODS: We analyzed single-cell RNA sequencing data from cardiac graft-infiltrating immunocytes to characterize the activation patterns and metabolic features of AIMs. We used flow cytometry to determine iNOS and PKM2 expression and MEK/ERK signaling activation levels in AIMs. We then generated macrophage-specific Mek1/2 knockout mice to determine the role of the MEK1/2-PKM2 pathway in the proinflammatory phenotype and glycolytic capacity of AIMs during HTR. RESULTS: Single-cell RNA sequencing analysis showed that AIMs had a significantly elevated proinflammatory and glycolytic phenotype. Flow cytometry analysis verified that iNOS and PKM2 expressions were significantly upregulated in AIMs. Moreover, MEK/ERK signaling was activated in AIMs and positively correlated with proinflammatory and glycolytic signatures. Macrophage-specific Mek1/2 deletion significantly protected chronic cardiac allograft rejection and inhibited the proinflammatory phenotype and glycolytic capacity of AIMs. Mek1/2 ablation also reduced the proinflammatory phenotype and glycolytic capacity of lipopolysaccharides + interferon-γ-stimulated macrophages. Mek1/2 ablation impaired nuclear translocation and PKM2 expression in macrophages. PKM2 overexpression partially restored the proinflammatory phenotype and glycolytic capacity of Mek1/2 -deficient macrophages. Moreover, trametinib, an Food and Drug Administration-approved MEK1/2 inhibitor, ameliorated chronic cardiac allograft rejection. CONCLUSIONS: These findings suggest that the MEK1/2-PKM2 pathway is essential for immunometabolic reprogramming of proinflammatory AIMs, implying that it may be a promising therapeutic target in clinical heart transplantation.
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Rejeição de Enxerto , Transplante de Coração , MAP Quinase Quinase 1 , MAP Quinase Quinase 2 , Macrófagos , Camundongos Knockout , Animais , Transplante de Coração/efeitos adversos , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/metabolismo , Rejeição de Enxerto/patologia , Rejeição de Enxerto/genética , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , MAP Quinase Quinase 2/metabolismo , MAP Quinase Quinase 1/metabolismo , MAP Quinase Quinase 1/genética , Proteínas de Ligação a Hormônio da Tireoide , Camundongos Endogâmicos C57BL , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Masculino , Transdução de Sinais , Proteínas de Transporte/metabolismo , Proteínas de Transporte/genética , Glicólise , Piruvato Quinase/metabolismo , Piruvato Quinase/genética , Modelos Animais de Doenças , Fenótipo , AloenxertosRESUMO
Thymic negative selection of the T cell receptor (TCR) repertoire is essential for establishing self-tolerance and acquired allograft tolerance following organ transplantation. However, it is unclear whether and how peripheral clonal deletion of alloreactive T cells induces transplantation tolerance. Here, we establish that programmed cell death protein 1 (PD-1) is a hallmark of alloreactive T cells and is associated with clonal expansion after alloantigen encounter. Moreover, we found that diphtheria toxin receptor (DTR)-mediated ablation of PD-1+ cells reshaped the TCR repertoire through peripheral clonal deletion of alloreactive T cells and promoted tolerance in mouse transplantation models. In addition, by using PD-1-specific depleting antibodies, we found that antibody-mediated depletion of PD-1+ cells prevented heart transplant rejection and the development of experimental autoimmune encephalomyelitis (EAE) in humanized PD-1 mice. Thus, these data suggest that PD-1 is an attractive target for peripheral clonal deletion and induction of immune tolerance.
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Deleção Clonal , Tolerância Imunológica , Camundongos Endogâmicos C57BL , Receptor de Morte Celular Programada 1 , Animais , Receptor de Morte Celular Programada 1/imunologia , Camundongos , Deleção Clonal/imunologia , Tolerância Imunológica/imunologia , Humanos , Encefalomielite Autoimune Experimental/imunologia , Transplante de Coração , Linfócitos T/imunologia , Camundongos Knockout , Camundongos Endogâmicos BALB C , FemininoRESUMO
BACKGROUND: Donation after circulatory death (DCD) heart transplantation (HTx) significantly expands the donor pool and reduces waitlist mortality. However, high-level evidence-based data on its safety and effectiveness are lacking. This meta-analysis aimed to compare the outcomes between DCD and donation after brain death (DBD) HTxs. METHODS: Databases, including MEDLINE, Embase, CINAHL, and the Cochrane Central Register of Controlled Trials, were systematically searched for randomized controlled trials and observational studies reporting the outcomes of DCD and DBD HTxs published from 2014 onward. The data were pooled using random-effects models. Risk ratios (RRs) with 95% confidence intervals (CIs) were used as the summary measures for categorical outcomes and mean differences were used for continuous outcomes. RESULTS: Twelve eligible studies were included in the meta-analysis. DCD HTx was associated with lower 1-y mortality rate (DCD 8.13% versus DBD 10.24%; RRâ =â 0.75; 95% CI, 0.59-0.96; Pâ =â 0.02) and 5-y mortality rate (DCD 14.61% versus DBD 20.57%; RRâ =â 0.72; 95% CI, 0.54-0.97; Pâ =â 0.03) compared with DBD HTx. CONCLUSIONS: Using the current DCD criteria, HTx emerges as a promising alternative to DBD transplantation. The safety and feasibility of DCD hearts deserve further exploration and investigation.
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BACKGROUND: One-carbon metabolism supports the activation, proliferation, and function of multiple immune cells. However, researchers have not clearly determined whether and how one-carbon metabolic enzymes contribute to heart transplant rejection. METHODS: We investigated the dynamic metabolic adaptation in grafts during heart transplant rejection by conducting transcriptomics, metabolomics and single-cell RNA sequencing studies of cardiac tissue from human and mouse heart transplant recipients. We also assessed the expression of the one-carbon metabolic enzyme methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) in cardiac grafts by immunofluorescence and flow cytometry assays. Then we constructed a murine heart transplant model with T cell-specific Mthfd2 knockout mice, analyzed T cells function by flow cytometry assays and enzyme-linked immunospot assays, and studied the mechanism by Cleavage Under Targets and Tagmentation assays. Finally, we studied the effect of a pharmacological inhibitor of MTHFD2 in humanized skin transplant model. RESULTS: We revealed that the one-carbon metabolism enzyme MTHFD2 was a hallmark of alloreactive T cells and was linked to T cell proliferation and function after exposure to alloantigen. And, Mthfd2 ablation prevented murine heart transplant rejection. Mechanistically, we found Mthfd2 ablation affected the interferon regulatory factor 4/programmed death-1 pathway through a metabolic-epigenetic mechanism involving H3K4me3. Furthermore, we found that inhibiting MTHFD2 attenuated human allograft rejection in a humanized skin transplant model. CONCLUSIONS: These data show that the one-carbon metabolic enzyme MTHFD2 serves as a metabolic checkpoint of alloreactive T cells and suggest that it may be a potential therapeutic target for heart transplant rejection.
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Immune checkpoint blockade (ICB), including anti-cytotoxic T-lymphocyte associated protein 4 (CTLA-4), benefits only a limited number of patients with cancer. Understanding the in-depth regulatory mechanism of CTLA-4 protein stability and its functional significance may help identify ICB resistance mechanisms and assist in the development of novel immunotherapeutic modalities to improve ICB efficacy. Here, we identified that TNF receptor-associated factor 6 (TRAF6) mediates Lys63-linked ubiquitination and subsequent lysosomal degradation of CTLA-4. Moreover, by using TRAF6-deficient mice and retroviral overexpression experiments, we demonstrated that TRAF6 promotes CTLA-4 degradation in a T-cell-intrinsic manner, which is dependent on the RING domain of TRAF6. This intrinsic regulatory mechanism contributes to CD8+ T-cell-mediated antitumor immunity in vivo. Additionally, by using an OX40 agonist, we demonstrated that the OX40-TRAF6 axis is responsible for CTLA-4 degradation, thereby controlling antitumor immunity in both tumor-bearing mice and patients with cancer. Overall, our findings demonstrate that the OX40-TRAF6 axis promotes CTLA-4 degradation and is a potential therapeutic target for the improvement of T-cell-based immunotherapies.
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Neoplasias , Fator 6 Associado a Receptor de TNF , Animais , Humanos , Camundongos , Linfócitos T CD8-Positivos , Antígeno CTLA-4 , ImunoterapiaRESUMO
Rationale: Transplant rejection is a major impediment to long-term allograft survival, in which the actions of immune cells are of fundamental importance. However, the immune cell dynamics and local intercellular communication of acute cardiac allograft rejection are not completely clear. Methods: Here we performed single-cell RNA sequencing on CD45+ immune cells isolated from cardiac grafts and spleens in a model of murine heterotopic heart transplantation. Moreover, we applied unsupervised clustering, functional enrichment analysis, cell trajectory construction and intercellular communication analysis to explore the immune cell dynamics and local intercellular communication of acute cardiac allograft rejection at single-cell level. The effect of CXCR3 antagonist and neutralizing antibody against its ligand on allograft rejection and T cell function was evaluated in murine heart transplantation model. Results: We presented the immune cell landscape of acute murine cardiac allograft rejection at single-cell resolution, and uncovered the functional characteristics and differentiation trajectory of several alloreactive cell subpopulations, including Mki67hi CTLs, Ccl5hi CTLs, activated Tregs and alloreactive B cells. We demonstrated local intercellular communication and revealed the upregulation of CXCR3 and its ligands in cardiac allografts. Finally, CXCR3 blockade significantly suppressed acute cardiac allograft rejection and inhibited the alloreactive T cell function. Conclusions: These results provide a new insight into the immune cell dynamics and local intercellular communication of acute cardiac allograft rejection, and suggest CXCR3 pathway may serve as a potential therapeutic target for transplant rejection.
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Transplante de Coração , Aloenxertos , Animais , Anticorpos Neutralizantes , Comunicação Celular , Rejeição de Enxerto , Transplante de Coração/métodos , Humanos , Ligantes , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Análise de Sequência de RNA , Doadores de TecidosRESUMO
Background: Graft vascular disease (GVD), which limits the long-term survival of patients after solid-organ transplantation, is associated with both immune responses and nonimmune factors, including dyslipidemia. Recent studies have shown that inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9), a U.S. Federal Drug Administration-approved treatment for hyperlipidemia, reduces cardiovascular events, regulates inflammatory responses, and enhances the efficacy of immune checkpoint therapy in cancer treatment through a cholesterol-independent mechanism. However, whether targeting PCSK9 is a potential therapeutic strategy for GVD remains unknown. Methods: Serum samples and grafts were harvested from male mice undergoing abdominal aortic transplantation. The pathological alterations in the aortic grafts were detected by hematoxylin and eosin staining, Verhoeff's Van Gieson staining, and Masson staining. Inflammatory cell infiltration and proinflammatory cytokine expression in the aortic grafts were detected by immunohistochemistry and quantitative real-time polymerase chain reaction (qRT-PCR), respectively. The regulatory effects of PCSK9 on vascular smooth muscle cell (VSMC) migration and proliferation were examined by transwell, EdU, and western blot assays. The effect of Evolocumab, a PCSK9 inhibitor, on GVD in humanized PCSK9 mice was also evaluated. Results: PCSK9 was upregulated in the serum, grafts, and liver of mice in the allograft group subjected to abdominal aortic transplantation. Pcsk9 knockout significantly reduced vascular stenosis, the intimal hyperplasia area and collagen deposition. Pcsk9 depletion also inhibited macrophage recruitment and the mRNA expression of proinflammatory cytokines in aortic grafts. Furthermore, Pcsk9 knockout suppressed the migration and proliferation of VSMCs, which was related to the inhibition of NLRP3 inflammasome activation. Meanwhile, Evolocumab significantly ameliorated GVD in humanized PCSK9 mice. Conclusion: PCSK9 is upregulated in a mouse model of GVD, and Pcsk9 knockout reduces vascular occlusion, suggesting that PCSK9 may be a promising target for the treatment of GVD.
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Pró-Proteína Convertase 9 , Doenças Vasculares , Animais , Humanos , Inflamassomos , Masculino , Camundongos , Músculo Liso Vascular/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Pró-Proteína Convertase 9/genética , Pró-Proteína Convertase 9/metabolismoRESUMO
[This corrects the article DOI: 10.7150/thno.43507.].
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Regulatory T cells play a crucial role in orchestrating immune response and maintaining immune tolerance, and the expression of the Foxp3 gene is indispensable to the differentiation of regulatory T cells. IL-4 shows strong inhibitory effects on Foxp3 expression and regulatory T cells differentiation, but the detailed mechanisms are still unclear. Here, we revealed that epigenetic modulations are key to this process. Specifically, the inhibition was found to be STAT6 dependent, and HDAC9 was involved with the process of histone deacetylation at the Foxp3 locus, subsequently decreasing chromatin accessibility and Foxp3 gene transcription. Pan-histone deacetylation inhibitors, especially sodium butyrate, notably abolished the inhibitory effects of IL-4 and ameliorated allergic airway inflammation in mouse models. Our research provides important mechanistic insights into how IL-4 inhibits regulatory T cells differentiation and suggests the therapeutic potential of the sodium butyrate in allergic airway disease.
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Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Interleucina-4/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Linfócitos T Reguladores/citologia , Animais , Diferenciação Celular/fisiologia , Epigênese Genética , Feminino , Humanos , Camundongos , Linfócitos T Reguladores/imunologiaRESUMO
Background: Dendritic cells (DCs) serve as an important part of the immune system and play a dual role in immune response. Mature DCs can initiate immune response, while immature or semi-mature DCs induce immune hyporesponsiveness or tolerance. Previous studies have shown that aspirin can effectively inhibit the maturation of DCs. However, the protective effect of aspirin on acute cardiac allograft rejection has not been studied. The aim of this study was to elucidate the effect of aspirin exert on allograft rejection. Methods: The model of MHC-mismatched (BALB/c to B6 mice) heterotopic heart transplantation was established and administered intraperitoneal injection with aspirin. The severity of allograft rejection, transcriptional levels of cytokines, and characteristics of immune cells were assessed. Bone marrow-derived dendritic cells (BMDCs) were generated with or without aspirin. The function of DCs was determined via mixed lymphocyte reaction (MLR). The signaling pathway of DCs was detected by Western blotting. Results: Aspirin significantly prolonged the survival of cardiac allograft in mouse, inhibited the production of pro-inflammatory cytokines and the differentiation of effector T cells (Th1 and Th17), as well as promoted the regulatory T cells (Treg). The maturation of DCs in the spleen was obviously suppressed with aspirin treatment. In vitro, aspirin decreased the activation of NF-κB signaling of DCs, as well as impeded MHCII and co-stimulatory molecules (CD80, CD86, and CD40) expression on DCs. Moreover, both the pro-inflammatory cytokines and function of DCs were suppressed by aspirin. Conclusion: Aspirin inhibits the maturation of DCs through the NF-κB signaling pathway and attenuates acute cardiac allograft rejection.
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Although studies in oncology have well explored the pharmacological effects of Birc5, little is known about its role in allogeneic T-cell responses. Therefore, the present study used a mouse model of acute heart allograft rejection to investigate the protective effect and mechanism of conditional knockout of Birc5 in T cells. Survivin (encoded by Birc5) was up-regulated in T cells activated in vivo and in vitro. Deletion of Birc5 in T cells attenuated acute heart allograft rejection by reducing the ratio of effector to naive T cells and Th1 to Tregs. In addition, deletion of Birc5 had no noticeable effect on proliferation but on apoptosis and the secretion of IFN-γ. The results revealed a significant increase in the percentage of Annexin V positive CD4+ T cells in the Birc5-/- group, compared to the WT. Moreover, there was significant increase in early apoptotic alloreactive T cells in Birc5-/- mice and this was partly mediated by caspase-3. Furthermore, treatment with YM155 inhibited acute heart allograft rejection in vivo and increased T-cell apoptosis in healthy human PBMCs in vitro. The results highlight a potential therapeutic target for the prevention and treatment of acute transplant rejection.
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Apoptose , Rejeição de Enxerto/prevenção & controle , Transplante de Coração/efeitos adversos , Survivina/fisiologia , Linfócitos T/imunologia , Doença Aguda , Animais , Caspase 3/fisiologia , Imidazóis/farmacologia , Interferon gama/biossíntese , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Naftoquinonas/farmacologia , Transplante HeterotópicoRESUMO
AIMS: Glibenclamide, a diabetes mellitus type 2 medication, has anti-inflammatory and autoimmune properties. This study investigated the effects of glibenclamide on transplant-induced arteriosclerosis as well as the underlying molecular events. METHODS: Male C57Bl/6 (H-2b) and BALB/c (H-2d) mice were used for aorta transplantation. We used hematoxylin and eosin (HE) and Elastic Van Gieson (EVG) staining for histological assessment, and qRT-PCR and ELISA to measure mRNA and protein levels. Mouse peritoneal macrophages were isolated for lipopolysaccharide (LPS) stimulation and glibenclamide treatment followed by ELISA, Western blot, and Transwell assays. RESULTS: Glibenclamide inhibited transplant-induced arteriosclerosis in vivo. Morphologically, glibenclamide reduced inflammatory cell accumulation and collagen deposition in the aortas. At the gene level, glibenclamide suppressed aortic cytokine mRNA levels, including interleukin-1ß (IL-1ß; 10.64 ± 3.19 vs. 23.77 ± 5.72; P < .05), tumor necrosis factor-α (TNF-α; 4.59 ± 0.78 vs. 13.89 ± 5.42; P < .05), and monocyte chemoattractant protein-1 (MCP-1; 202.66 ± 23.44 vs. 1172.73 ± 208.80; P < .01), while IL-1ß, TNF-α, and MCP-1 levels were also reduced in the mouse sera two weeks after glibenclamide treatment (IL-1ß, 39.40 ± 13.56 ng/ml vs. 78.96 ± 9.39 ng/ml; P < .01; TNF-α, 52.60 ± 13.00 ng/ml vs. 159.73 ± 6.76 ng/ml; P < .01; and MCP-1, 56.60 ± 9.07 ng/ml vs. 223.07 ± 36.28 ng/ml; P < .001). Furthermore, glibenclamide inhibited macrophage expression and secretion of inflammatory factors in vitro through suppressing activation of the nuclear factor-κB (NF-κB) pathway and MCP-1 production. CONCLUSION: Glibenclamide protected against aorta transplantation-induced arteriosclerosis by reducing inflammatory factors in vivo and inhibited macrophage migration and MCP-1 production in vitro.
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Arteriosclerose/tratamento farmacológico , Movimento Celular/efeitos dos fármacos , Quimiocina CCL2/antagonistas & inibidores , Regulação da Expressão Gênica/efeitos dos fármacos , Glibureto/farmacologia , Macrófagos Peritoneais/efeitos dos fármacos , Transplante de Órgãos/efeitos adversos , Animais , Apoptose/efeitos dos fármacos , Arteriosclerose/etiologia , Arteriosclerose/metabolismo , Arteriosclerose/patologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Quimiocina CCL2/genética , Quimiocina CCL2/metabolismo , Feminino , Hipoglicemiantes/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BLRESUMO
Chronic allograft dysfunction (CAD) resulting from fibrosis is the major limiting factor for long-term survival of lung transplant patients. Myofibroblasts promote fibrosis in multiple organs, including the lungs. In this study, we identified PLK1 as a promoter of myofibroblast differentiation and investigated the mechanism by which its inhibition alleviates transplant-associated obliterative bronchiolitis (OB) during CAD. High-throughput bioinformatic analyses and experiments using the murine heterotopic tracheal transplantation model revealed that PLK1 is upregulated in grafts undergoing CAD as compared with controls, and that inhibiting PLK1 alleviates OB in vivo. Inhibition of PLK1 in vitro reduced expression of the specific myofibroblast differentiation marker α-smooth muscle actin (α-SMA) and decreased phosphorylation of both MEK and ERK. Importantly, we observed a similar phenomenon in human primary fibroblasts. Our results thus highlight PLK1 as a promising therapeutic target for alleviating transplant-associated OB through suppression of TGF-ß1-mediated myofibroblast differentiation.
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Bronquiolite Obliterante/patologia , Proteínas de Ciclo Celular/metabolismo , Rejeição de Enxerto/patologia , Transplante de Pulmão/efeitos adversos , Miofibroblastos/patologia , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Actinas/metabolismo , Aloenxertos/citologia , Aloenxertos/efeitos dos fármacos , Aloenxertos/patologia , Animais , Bronquiolite Obliterante/etiologia , Bronquiolite Obliterante/prevenção & controle , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/genética , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/genética , Células Cultivadas , Doença Crônica/prevenção & controle , Biologia Computacional , Modelos Animais de Doenças , Fibrose , Técnicas de Silenciamento de Genes , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/prevenção & controle , Voluntários Saudáveis , Humanos , Pulmão/citologia , Pulmão/efeitos dos fármacos , Pulmão/patologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/genética , Masculino , Camundongos , Miofibroblastos/efeitos dos fármacos , Células NIH 3T3 , Via de Pentose Fosfato/efeitos dos fármacos , Fosforilação , Cultura Primária de Células , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas Proto-Oncogênicas/genética , Pteridinas/farmacologia , Pteridinas/uso terapêutico , RNA-Seq , Traqueia/citologia , Traqueia/efeitos dos fármacos , Traqueia/patologia , Traqueia/transplante , Fator de Crescimento Transformador beta1/metabolismo , Regulação para Cima , Quinase 1 Polo-LikeRESUMO
Background: The immune checkpoint cytotoxic T lymphocyte antigen-4 (CTLA-4), induced upon T cell activation but degraded quickly, has been targeted in the clinical therapy of advanced cancers and autoimmune diseases. However, whether inhibiting CTLA-4 degradation ameliorates transplant rejection remains unknown. Methods: The CTLA-4 expression in activated murine T cells treated with the inhibitors mediating protein degradation was detected by flow cytometry (FCM). CD45.1 mice, which received TEa T cells and underwent heart transplantation, were administrated with the inhibitor. Subsequently, CTLA-4 expression of TEa T cells was analyzed. Murine skin and heart transplantation models were built, then the survival and histopathology of the allografts, and T cell subsets in the spleens of each group were compared. Results: Chloroquine (CQ) was identified as an inhibitor of CTLA-4 degradation, which augmented both surface and total CTLA-4 expression in T cells. It considerably prolonged the skin and heart allograft survival time and reduced the infiltration of inflammatory cells in allografts. Besides decreasing the frequencies of the CD4+ and CD8+ effector T cells, especially IFN-γ producing T cells, CQ also increased the proportion of regulatory T cells in the spleen. The CTLA-4 blockade abrogated the benefits of CQ on the survival of heart allografts. Moreover, CQ enhanced CTLA-4 expression in activated human T cells and reduced the secretion of IFN-γ in human mixed lymphocyte reaction. Conclusion: Targeting CTLA-4 degradation provides a novel means to prevent transplant rejection and induce transplant tolerance.
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Antígeno CTLA-4/agonistas , Cloroquina/farmacologia , Rejeição de Enxerto/prevenção & controle , Transplante de Coração/efeitos adversos , Transplante de Pele/efeitos adversos , Animais , Autofagia/efeitos dos fármacos , Antígeno CTLA-4/metabolismo , Linhagem Celular , Cloroquina/uso terapêutico , Modelos Animais de Doenças , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/efeitos dos fármacos , Sobrevivência de Enxerto/imunologia , Humanos , Interferon gama/antagonistas & inibidores , Interferon gama/metabolismo , Ativação Linfocitária , Teste de Cultura Mista de Linfócitos , Lisossomos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Transgênicos , Proteólise/efeitos dos fármacosRESUMO
BACKGROUND: The development of thoracic aortic aneurysm and dissection (TAAD) is mediated by inflammasome activation, which exacerbates the secretion of pro-inflammatory cytokines, chemokines, matrix metalloproteinases (MMPs), and reactive oxygen species (ROS). The glycolytic enzyme pyruvate kinase M2 (PKM2) has shown a protective role against various disorders with an inflammatory basis, such as sepsis, tumorigenesis, and diabetic nephropathy. However, its potential role in TAAD has not been investigated so far. APPROACH AND RESULTS: We analyzed aortic tissues from TAAD patients and the ß-aminopropionitrile fumarate (BAPN)-induced mouse model of TAAD and observed elevated levels of PKM2 in the aortic lesions of both. Treatment with the PKM2 activator TEPP-46 markedly attenuated the progression of TAAD in the mouse model as demonstrated by decreased morbidity and luminal diameter of the aorta. In addition, the thoracic aortas of the BAPN-induced mice showed reduced monocytes and macrophages infiltration and lower levels of IL-1ß, MMPs, and ROS when treated with TEPP-46. Furthermore, TEPP-46 treatment also suppressed the activation of the NOD-like receptor (NLR) family and pyrin domain-containing protein 3 (NLRP3) inflammasome by downregulating p-STAT3 and HIF1-α. CONCLUSION: Pyruvate kinase M2 plays a protective role in TAAD development, and its activation is a promising therapeutic strategy against the progression of TAAD.