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General anesthesia is thought to suppress the immune system and negatively affect postoperative infection and the long-term prognosis of cancer. However, the mechanism underlying immunosuppression induced by general anesthetics remains unclear. In this study, we focused on propofol, which is widely used for sedation under general anesthesia and intensive care and examined its effects on the T cell function and T cell-dependent immune responses. We found that propofol suppressed T cell glycolytic metabolism, differentiation into effector T cells, and cytokine production by effector T cells. CD8 T cells activated and differentiated into effector cells in the presence of propofol in vitro showed reduced antitumor activity. Furthermore, propofol treatment suppressed the increase in the number of antigen-specific CD8 T cells during Listeria infection. In contrast, the administration of propofol improved inflammatory conditions in mouse models of inflammatory diseases, such as OVA-induced allergic airway inflammation, hapten-induced contact dermatitis, and experimental allergic encephalomyelitis. These results suggest that propofol may reduce tumor and infectious immunity by suppressing the T cell function and T cell-dependent immune responses while improving the pathogenesis and prognosis of chronic inflammatory diseases by suppressing inflammation.
Assuntos
Linfócitos T CD8-Positivos , Propofol , Propofol/farmacologia , Animais , Camundongos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Linfócitos T/imunologia , Linfócitos T/efeitos dos fármacos , Ativação Linfocitária/efeitos dos fármacos , Inflamação/imunologia , Diferenciação Celular/efeitos dos fármacos , Citocinas/metabolismo , Listeriose/imunologia , Modelos Animais de Doenças , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/tratamento farmacológico , FemininoRESUMO
We observed a case of pancreatic metastasis of lung cancer being resected following chemoradiotherapy and reported with a review of the literature. The patient was a 60-year-old man and previously underwent an upper lobectomy of the right lung for the primary lesion and chemoradiotherapy for the metastatic lesion in the lower lobe of the right lung. During the follow-up period, positron emission tomography-computed tomography scan revealed a tumor in the pancreatic body, which was a hyperechoic mass on endoscopic ultrasonography (EUS) and hypervascularity on Sonazoid angiography. Fine needle aspiration cytology under EUS revealed dense growth of tumor cells with increased nuclear chromatin, markedly atypical nuclei, and eosinophilic sporangia. Immunostaining showed CK7 (+), CK20 (-), TTF-1 (+), and napsin A (+). He was diagnosed with pancreatic metastasis of lung cancer, underwent preoperative chemoradiotherapy followed by distal pancreatectomy and splenectomy, and discharged without perioperative complications. The right lower lobe metastasis of lung cancer was detected during an outpatient visit following chemoradiotherapy. However, he was found rectal cancer and considered a scheduled surgery. Forty-two months postoperatively, he was found dead at home;the cause of death was shock due to extreme dehydration.
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Neoplasias Pulmonares , Neoplasias Pancreáticas , Masculino , Humanos , Pessoa de Meia-Idade , Pâncreas , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/terapia , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/terapia , Quimiorradioterapia , PulmãoRESUMO
It has been suggested that aging of the immune system (immunosenescence) results in a decline in the acquired immune response, which is associated with an increase in age-related tumorigenesis. T-cell senescence plays a critical role in immunosenescence and is involved in the age-related decline of the immune function, which increases susceptibility to certain cancers. However, it has been shown that CD8+ T cells with the senescent T-cell phenotype acquire an natural killer (NK) cell-like function and are involved in tumor elimination. Therefore, the role of senescent CD8+ T cells in tumor immunity remains to be elucidated. In this study, we investigated the role of senescent CD8+ T cells in tumor immunity. In a murine model of transferred with B16 melanoma, lung metastasis was significantly suppressed in aged mice (age ≥30 weeks) in comparison to young mice (age 6-10 weeks). We evaluated the cytotoxic activity of CD8+ T cells in vitro and found that CD8+ T cells from aged mice activated in vitro exhibited increased cytotoxic activity in comparison to those from young mice. We used Menin-deficient effector T cells as a model for senescent CD8+ T cells and found that cytotoxic activity and the expression of NK receptors were upregulated in Menin-deficient senescent CD8+ T cells. Furthermore, Menin-deficient CD8+ T cells can eliminate tumor cells in an antigen-independent manner. These results suggest that senescent effector CD8+ T cells may contribute to tumor immunity in the elderly by acquiring NK-like innate immune functions, such as antigen-independent cytotoxic activity.
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Linfócitos T CD8-Positivos , Melanoma Experimental , Camundongos , Animais , Células Matadoras Naturais , Imunidade Adaptativa , Melanoma Experimental/metabolismo , EnvelhecimentoRESUMO
CD8+ T cells play a central role in antitumor immune responses. Epigenetic gene regulation is essential to acquire the effector function of CD8+ T cells. However, the role of Utx, a demethylase of histone H3K27, in antitumor immunity remains unclear. In this study, we examined the roles of Utx in effector CD8+ T-cell differentiation and the antitumor immune response. In a murine tumor-bearing model, an increased tumor size and decreased survival rate were observed in T-cell-specific Utx KO (Utx KO) mice compared with wild-type (WT) mice. The number of CD8+ T cells in tumor-infiltrating lymphocytes (TILs) was significantly decreased in Utx KO mice. We found that the acquisition of effector function was delayed and attenuated in Utx KO CD8+ T cells. RNA sequencing revealed that the expression of effector signature genes was decreased in Utx KO effector CD8+ T cells, while the expression of naïve or memory signature genes was increased. Furthermore, the expression of Cxcr3, which is required for the migration of effector CD8+ T cells to tumor sites, was substantially decreased in Utx KO CD8+ T cells. These findings suggest that Utx promotes CD8+ T-cell-dependent antitumor immune responses partially through epigenetic regulation of the effector function.
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Linfócitos T CD8-Positivos , Epigênese Genética , Camundongos , Animais , Linfócitos T CD8-Positivos/metabolismo , Histona Desmetilases/genética , Histona Desmetilases/metabolismo , Regulação da Expressão Gênica , Histonas/metabolismoRESUMO
For general optical resolution, an optical resolution agent is necessary, and the best agent should be selected for each racemic compound. In this study, we will report that a novel optical resolution method by circularly polarized light (CPL) without any optical resolution agents has been developed by serially connecting two enantioselective reactions. These reactions we developed are the enantiomer-selective helix-sense-selective polymerization (ES-HSSP) and helix-sense-selective highly selective photocyclic aromatization (SCAT) by CPL (HS-SCAT). Since this significantly unique EPHS method (EPHS = ES-HSSP + HS-SCAT) does not need any optical resolution agents, any cocatalysts, and solvents for the selective decomposition reaction (HS-SCAT), this process is quite simple and convenient. Since this process does not include any decomposition of the target racemates themselves, both enantiomers could be obtained. The optical yields for isolated compounds that were enantiomerically separated by the EPHS method were very high, for example, 78%ee, 93%ee, and 85%ee for menthol, phenethyl alcohol, and 2-butanol, respectively. In addition, their chemical yields were around 85% to 94%. Therefore, the EPHS method was found to show an excellent performance and can be applied to actual optical resolution for a wide range of racemic compounds. This is the first absolute optical resolution by CPL showing high optical and chemical yields and expected to become a practical optical resolution method.
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Acetileno , EstereoisomerismoRESUMO
Glucocorticoids (GCs), immunosuppressive, and anti-inflammatory agents have various effects on T cells. However, the long-term influence of GCs on the T cell-mediated immune response remain to be elucidated. We demonstrated that the administration of GC during the TCR-mediated activation phase induced long-lasting suppression of glycolysis, even after the withdrawal of GC. The acquisition of the effector functions was inhibited, while the expression of PD-1 was increased in CD8 T cells activated in the presence of GC. Furthermore, adoptive transfer experiments revealed that GC-treated CD8 T cells reduced memory T cell formation and anti-tumor activity. These findings reveal that GCs have long-lasting influence on the T cell-mediated immune response via modulation of T cell metabolism.
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Linfócitos T CD8-Positivos/metabolismo , Glucocorticoides/farmacologia , Glucose/metabolismo , Imunidade , Terapia de Imunossupressão , Animais , Antígenos/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Feminino , Glicólise/efeitos dos fármacos , Imunidade/efeitos dos fármacos , Memória Imunológica/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Prednisolona/farmacologiaRESUMO
BACKGROUND: The aim of this study is to assess the positional accuracy of image fusions of the skull base region using different magnetic resonance imaging (MRI) and computed tomography (CT) image pairs. METHODS: An image set of 3D fast imaging employing steady-state acquisition-C (FIESTA-C) was used as the base image set. Image fusions were performed using an image set with different fields of view (FOVs): one with different matrix size, one with a different sequence of 3D spoiled gradient recalled acquisition, and one with different modality (CT), using a phantom including multi columnar objects. Position of columns at the center, and 4 and 8 cm from the center were measured. The displacements between the base image set and fused image set were measured. For slices with different z-positions, the displacement of the 8-cm column was assessed. For 20 clinical MRI cases, the distance between the dorsum sellae and the cranial nerves was measured. RESULTS: No significant differences were found between the different FOVs or image sequences. However, with the different matrix sizes and modalities, significant displacements were observed, although they were all within 0.5 mm. Similar displacements were observed in the slices at different z-positions. All cranial nerves were located within 40 mm of the dorsum sellae. CONCLUSIONS: The displacements following image fusion were within approximately 0.5 mm, even at 8 cm from the center. This suggests that the region where the cranial nerves are located, within 40 mm of the dorsum sellae, had no risk of positional error following image fusion.
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Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X , Humanos , Imageamento Tridimensional , Imageamento por Ressonância Magnética/métodos , Procedimentos Neurocirúrgicos , Base do Crânio/diagnóstico por imagem , Base do Crânio/cirurgia , Tomografia Computadorizada por Raios X/métodosRESUMO
We report our experience with needlescopic splenectomy (NS) for the surgical treatment of idiopathic thrombocytopenic purpura using a 3-mm needlescope with three ports. One patient was male and two were females, and their mean age was 58 years. The patient was placed in the right lateral decubitus position. The first 12-mm port was introduced through the lateral margin of the left rectus abdominis muscle, and the other two 3-mm ports were inserted in the left upper quadrant. NS was performed by a standard technique under the observation of 3.3-mm needlescope. The surgical procedure was successfully completed in all the patients. The mean duration of surgery, intra-operative bleeding volume and post-operative hospital stay were 176 min, 70 ml and 4.7 days, respectively. There were no particular peri-operative complications in spite of dense adhesions or simultaneous laparoscopic procedures. Our method is safe and feasible with low morbidity and without impairing cosmetic benefits.
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Th2 cytokine such as IL-4, IL -5 and IL-13 are important therapeutic targets for Th2-type chronic inflammation. Several biologics targeting Th2 cytokine and its receptors are effective in clinical practice; however, the development of small-molecule compounds that inhibit Th2 cytokine productions is awaited. We found that an inhibitor for pyruvate dehydrogenase kinase (PDHK) suppresses the differentiation of IL-5/IL-13-producing Th2 cells. The expression of the Th2-related transcriptional factors Pparγ was decreased by treatment with inhibitor, whereas Gata3, a master regulator of Th2 cell differentiation, remained unchanged. The oxygen consumption rate was unaffected, whereas the level of farnesylated proteins was decreased by the PDHK inhibitor. Furthermore, the inhibitors for farnesyltransferase and hydroxymethylglutaryl-CoA reductase showed an inhibitory effect similar to that of the PDHK inhibitor. These results suggest that the mevalonate biosynthesis and subsequent protein prenylation may be novel therapeutic target for Th2 cell-dependent immune dysregulation, such as in allergic diseases.
Assuntos
Glicólise , Ácido Mevalônico/metabolismo , Células Th2/citologia , Anilidas/farmacologia , Animais , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Citocinas/metabolismo , Feminino , Glicólise/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Inibidores de Proteínas Quinases/farmacologia , Piruvato Desidrogenase Quinase de Transferência de Acetil/antagonistas & inibidores , Piruvato Desidrogenase Quinase de Transferência de Acetil/metabolismo , Células Th2/efeitos dos fármacos , Células Th2/metabolismoRESUMO
Prefractionation of complex mixtures of proteins derived from biological samples is indispensable for proteome analysis via top-down mass spectrometry (MS). Polyacrylamide gel electrophoresis (PAGE), which enables high-resolution protein separation based on molecular size, is a widely used technique in biochemical experiments and has the potential to be useful in sample fractionation for top-down MS analysis. However, the lack of a means to efficiently recover the separated proteins in-gel has always been a barrier to its use in sample prefractionation. In this study, we present a novel experimental workflow, called Passively Eluting Proteins from Polyacrylamide gels as Intact species for MS ("PEPPI-MS"), which allows top-down MS of PAGE-separated proteins. The optimization of Coomassie brilliant blue staining followed by the passive extraction step in the PEPPI-MS workflow enabled the efficient recovery of proteins, separated on commercial precast gels, from a wide range of molecular weight regions in under 10 min. Two-dimensional separation combining offline PEPPI-MS with online reversed-phase liquid chromatographic separation resulted in identification of over 1000 proteoforms recovered from the target region of the gel (≤50 kDa). Given the widespread availability and relatively low cost of traditional sodium dodecyl sulfate (SDS)-PAGE equipment, the PEPPI-MS workflow will be a powerful prefractionation strategy for top-down proteomics.
Assuntos
Resinas Acrílicas , Eletroforese em Gel de Poliacrilamida , Espectrometria de MassasRESUMO
The cancer immunotherapies based on adoptive T cell therapy(ACT)has been receiving increased attention by improvement of the curative effect. T cells for ACT are harvested from the patient, then activated and expanded in vitro. However, in vitro activated T cells frequently show dysfunction after adoptive transfer, such as the exhaustion and the senescence. The exhausted/senescent T cells reduces the effector functions and fails to eliminate tumor cells. Therefore, the development of the culture method avoiding a T cellexhaustion and senescence. Recent findings revealthe dramatic changes of the metabolic status in T cells during T-cell receptor(TCR)-mediated activation. We recently reported that the activation status of glutaminolysis during TCR-stimulation determines the activated CD8 T cell fate. We considered that the therapeutic effect of ACT will be improved by the modulation of glutaminolysis. We demonstrated that the CD8 T cell exhaustion and/or senescence is prevented and the antitumor activity of adoptively transferred CD8 T cells is reinforced by the glutamine restriction during in vitro culture. The adoptively transferred CD8 T cells cultured under glutamine-restricted conditions shows higher infiltration in the tumor sites than that of CD8 T cells cultured under normal conditions. The expression of inhibitory receptors, such as PD-1 is decreased in tumor-infiltrating CD8 T cells cultured under glutamine-restricted conditions. Furthermore, the restriction of glutamine during CD8 T cell activation in vitro drives memory T cell development after adoptive transfer. The effect of glutamine restriction is antagonized by a-ketoglutarate, a metabolite of glutaminolysis. Thus, our recent findings suggest that the glutamine-restricted culture of CD8 T cells in vitro will improve the efficacy of CD8 T cell-based ACT.
Assuntos
Linfócitos T CD8-Positivos , Glutamina , Humanos , Imunoterapia Adotiva , Ativação Linfocitária , Receptores de Antígenos de Linfócitos TRESUMO
The transcription factor GATA3 is a master regulator that modulates T helper 2 (Th2) cell differentiation and induces expression of Th2 cytokines, such as IL-4, IL-5, and IL-13. Th2 cytokines are involved in the protective immune response against foreign pathogens, such as parasites. However, excessive production of Th2 cytokines results in type-2 allergic inflammation. Therefore, the application of a GATA3 inhibitor provides a new therapeutic strategy to regulate Th2 cytokine production. Here, we established a novel high-throughput screening system for an inhibitor of a DNA-binding protein, such as a transcription factor, and identified pyrrothiogatain as a novel inhibitor of GATA3 DNA-binding activity. Pyrrothiogatain inhibited the DNA-binding activity of GATA3 and other members of the GATA family. Pyrrothiogatain also inhibited the interaction between GATA3 and SOX4, suggesting that it interacts with the DNA-binding region of GATA3. Furthermore, pyrrothiogatain significantly suppressed Th2 cell differentiation, without impairing Th1 cell differentiation, and inhibited the expression and production of Th2 cytokines. Our results suggest that pyrrothiogatain regulates the differentiation and function of Th2 cells via inhibition of GATA3 DNA binding activity, which demonstrates the efficiency of our drug screening system for the development of novel small compounds that inhibit the DNA-binding activity of transcription factors.
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Fator de Transcrição GATA4/química , Fator de Transcrição GATA4/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Células Th2/citologia , Animais , Sítios de Ligação/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Células HEK293 , Humanos , Células Jurkat , Camundongos , Ligação Proteica/efeitos dos fármacos , Fatores de Transcrição SOXC/metabolismo , Células Th2/efeitos dos fármacos , Células Th2/metabolismoRESUMO
Cerebral small vessel disease (CSVD) is not only a cause of vascular dementia (VD) but also a contributing factor to Alzheimer's disease (AD). The essential pathological feature of CSVD is the disruption of blood-brain barrier (BBB). Dysfunction of BBB due to degeneration of both endothelial cells and pericytes in capillaries leads to neuronal damage and progressive brain atrophy. Moreover, deterioration of amyloid-ß (Aß) clearance due to the failure of the transvascular BBB transport system results in accumulation of Aß in the brain. Intravenous infusion of mesenchymal stem cells (MSCs) elicits functional recovery in experimental models including stroke and spinal cord injury. One effect of MSCs is to restore disrupted BBB through remodeling of microvasculature. Using spontaneously hypertensive rats (stroke-prone) with impaired cognitive function as a CSVD model, we have shown that infused MSCs has a therapeutic effect for cognitive function. Restoration of BBB function via remodeling of microvasculature and inhibition of Aß accumulation could inhibit progressive brain atrophy and lead to restore cognitive dysfunction. Gene expression analysis indicated that infused MSCs activates both transforming growth factor-ß and angiopoietin 1 signaling pathways and promotes the remodeling of microvasculature. Thus, infused MSCs may represent a novel therapy for both VD and AD.
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Doenças de Pequenos Vasos Cerebrais/complicações , Cognição/fisiologia , Disfunção Cognitiva/terapia , Transplante de Células-Tronco Mesenquimais , Reconhecimento Psicológico/fisiologia , Animais , Comportamento Animal/fisiologia , Barreira Hematoencefálica/patologia , Doenças de Pequenos Vasos Cerebrais/patologia , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/patologia , Modelos Animais de Doenças , Infusões Intravenosas , Células-Tronco Mesenquimais , Ratos , Ratos Endogâmicos SHRRESUMO
Although the methylation status of histone H3K27 plays a critical role in CD4+ T cell differentiation and its function, the role of Utx histone H3K27 demethylase in the CD8+ T cell-dependent immune response remains unclear. We therefore generated T cell-specific Utx flox/flox Cd4-Cre Tg (Utx KO) mice to determine the role of Utx in CD8+ T cells. Wild-type (WT) and Utx KO mice were infected with Listeria monocytogenes expressing OVA to analyze the immune response of Ag-specific CD8+ T cells. There was no significant difference in the number of Ag-specific CD8+ T cells upon primary infection between WT and Utx KO mice. However, Utx deficiency resulted in more Ag-specific CD8+ T cells upon secondary infection. Adoptive transfer of Utx KO CD8+ T cells resulted in a larger number of memory cells in the primary response than in WT. We observed a decreased gene expression of effector-associated transcription factors, including Prdm1 encoding Blimp1, in Utx KO CD8+ T cells. We confirmed that the trimethylation level of histone H3K27 in the Prdm1 gene loci in the Utx KO cells was higher than in the WT cells. The treatment of CD8+ T cells with Utx-cofactor α-ketoglutarate hampered the memory formation, whereas Utx inhibitor GSK-J4 enhanced the memory formation in WT CD8+ T cells. These data suggest that Utx negatively controls the memory formation of Ag-stimulated CD8+ T cells by epigenetically regulating the gene expression. Based on these findings, we identified a critical link between Utx and the differentiation of Ag-stimulated CD8+ T cells.
Assuntos
Antígenos CD8/imunologia , Histonas/imunologia , Memória Imunológica/imunologia , Histona Desmetilases com o Domínio Jumonji/imunologia , Animais , Benzazepinas/farmacologia , Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular , Histonas/metabolismo , Memória Imunológica/efeitos dos fármacos , Histona Desmetilases com o Domínio Jumonji/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pirimidinas/farmacologiaRESUMO
BACKGROUND: Intravenous infusion of mesenchymal stem cells (MSCs) derived from adult bone marrow elicits functional recovery in rat stroke models and clinical studies in patients are ongoing. Brain derived neurotrophic factor (BDNF) is a neurotrophic factor produced by MSCs and may contribute to their therapeutic efficacy. The purpose of the current study was to determine if BDNF is elevated in infarcted brain and in which compartment of blood (plasma or serum) after intravenous MSC infusion in a middle cerebral artery occlusion (MCAO) model in the rat. METHODS: In rats, a permanent middle cerebral artery occlusion (MCAO) was induced by intraluminal vascular occlusion with a microfilament and MSCs were intravenously administered 6 h after right MCAO induction. Enzyme-linked immunosorbent assay (ELISA) analysis of brain, serum and plasma BDNF were performed after the MSC infusion following the MCAO induction. Lesion volume was assessed using magnetic resonance imaging. Functional outcome was assessed using the Limb Placement Test. RESULTS: Infused MSCs reduced lesion volume and elicited functional improvement compared to the vehicle infused group. ELISA analysis of the MSC treated group revealed an increase BDNF levels in the infarcted hemisphere of the brain and plasma, but not in serum. The MSC group showed a greater increase in BDNF levels than sham control. In the MSC group, the expression of increased plasma BDNF levels correlated with increased brain BDNF levels. CONCLUSIONS: These results support the hypothesis that BDNF levels in plasma, but not serum, may be more appropriate to detect circulating BDNF in vivo following MSC infusion in a cerebral infarction rat model of ischemic stroke. Further, plasma BDNF might reflect in vivo functional viability of infused MSCs after stroke.
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Fator Neurotrófico Derivado do Encéfalo/sangue , Transplante de Células-Tronco Mesenquimais/métodos , Plasma , Acidente Vascular Cerebral/sangue , Acidente Vascular Cerebral/terapia , Animais , Modelos Animais de Doenças , Infarto da Artéria Cerebral Média/complicações , Ratos , Ratos Sprague-Dawley , Acidente Vascular Cerebral/etiologiaRESUMO
OBJECTIVE: Morbidity and mortality in patients with posterior circulation stroke remains an issue despite advances in acute stroke therapies. The intravenous infusion of mesenchymal stem cells (MSCs) elicits therapeutic efficacy in experimental supratentorial stroke models. However, since there are few reliable animal models of ischemia in the posterior circulation, the therapeutic approach with intravenous MSC infusion has not been tested. The objective of this study was to test the hypothesis that intravenously infused MSCs provide functional recovery in a newly developed model of brainstem infarction in rats. METHODS: Basilar artery (BA) occlusion (BAO) was established in rats by selectively ligating 4 points of the proximal BA with 10-0 nylon monofilament suture. The intravenous infusion of MSCs was performed 1 day after BAO induction. MRI and histological examinations were performed to assess ischemic lesion volume, while multiple behavioral tests were performed to evaluate functional recovery. RESULTS: The MSC-treated group exhibited a greater reduction in ischemic lesion volume, while behavioral testing indicated that the MSC-infused group had greater improvement than the vehicle group 28 days after the MSC infusion. Accumulated infused MSCs were observed in the ischemic brainstem lesion. CONCLUSIONS: Infused MSCs may provide neuroprotection to facilitate functional outcomes and reduce ischemic lesion volume as evaluated in a newly developed rat model of persistent BAO.
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OBJECTIVE: Intravenous infusion of mesenchymal stem cells (MSCs) derived from adult bone marrow improves behavioral function in rat models of cerebral infarction. Although clinical studies are ongoing, most studies have focused on the acute or subacute phase of stroke. In the present study, MSCs derived from bone marrow of rats were intravenously infused 8 weeks after the induction of a middle cerebral artery occlusion (MCAO) to investigate whether delayed systemic injection of MSCs improves functional outcome in the chronic phase of stroke in rats. METHODS: Eight weeks after induction of the MCAO, the rats were randomized and intravenously infused with either MSCs or vehicle. Ischemic volume and behavioral performance were examined. Blood-brain barrier (BBB) integrity was assessed by quantifying the leakage of Evans blue into the brain parenchyma after intravenous infusion. Immunohistochemical analysis was also performed to evaluate the stability of the BBB. RESULTS: Motor recovery was better in the MSC-treated group than in the vehicle-treated group, with rapid improvement (evident at 1 week post-infusion). In MSC-treated rats, reduced BBB leakage and increased microvasculature/repair and neovascularization were observed. CONCLUSIONS: These results indicate that the systemic infusion of MSCs results in functional improvement, which is associated with structural changes in the chronic phase of cerebral infarction, including in the stabilization of the BBB.
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The antitumor activity of activated CD8+ T cells in the tumor microenvironment seems to be limited due to their being metabolically unfit. This metabolic unfitness is closely associated with T-cell exhaustion and impairment of memory formation, which are barriers to successful antitumor adoptive immunotherapy. We therefore assessed the role of glutamine metabolism in the antitumor activity of CD8+ T cells using a tumor-inoculated mouse model. The adoptive transfer of tumor-specific CD8+ T cells cultured under glutamine-restricted (dGln) conditions or CD8+ T cells treated with specific inhibitors of glutamine metabolism efficiently eliminated tumors and led to better survival of tumor-inoculated mice than with cells cultured under control (Ctrl) conditions. The decreased expression of PD-1 and increased Ki67 positivity among tumor-infiltrating CD8+ T cells cultured under dGln conditions suggested that the inhibition of glutamine metabolism prevents CD8+ T-cell exhaustion in vivo. Furthermore, the transferred CD8+ T cells cultured under dGln conditions expanded more efficiently against secondary OVA stimulation than did CD8+ T cells under Ctrl conditions. We found that the expression of a pro-survival factor and memory T cell-related transcription factors was significantly higher in CD8+ T cells cultured under dGln conditions than in those cultured under Ctrl conditions. Given these findings, our study uncovered an important role of glutamine metabolism in the antitumor activity of CD8+ T cells. The novel adoptive transfer of tumor-specific CD8+ T cells cultured in glutamine-restricted conditions may be a promising approach to improve the efficacy of cell-based adoptive immunotherapy.
Assuntos
Linfócitos T CD8-Positivos/transplante , Glutamina/deficiência , Timoma/terapia , Neoplasias do Timo/terapia , Animais , Linfócitos T CD8-Positivos/metabolismo , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Meios de Cultura/química , Humanos , Imunoterapia Adotiva/métodos , Camundongos , Timoma/imunologia , Timoma/metabolismo , Neoplasias do Timo/imunologia , Neoplasias do Timo/metabolismo , Microambiente Tumoral , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
While menin plays an important role in preventing T-cell dysfunction, such as senescence and exhaustion, the regulatory mechanisms remain unclear. We found that menin prevents the induction of dysfunction in activated CD8 T cells by restricting the cellular metabolism. mTOR complex 1 (mTORC1) signaling, glycolysis, and glutaminolysis are augmented by menin deficiency. Rapamycin treatment prevents CD8 T-cell dysfunction in menin-deficient CD8 T cells. Limited glutamine availability also prevents CD8 T-cell dysfunction induced by menin deficiency, and its inhibitory effect is antagonized by α-ketoglutarate (α-KG), an intermediate metabolite of glutaminolysis. α-KG-dependent histone H3K27 demethylation seems to be involved in the dysfunction in menin-deficient CD8 T cells. We also found that α-KG activates mTORC1-dependent central carbon metabolism. These findings suggest that menin maintains the T-cell functions by limiting mTORC 1 activity and subsequent cellular metabolism.