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1.
PLoS One ; 20(1): e0307534, 2025.
Artigo em Inglês | MEDLINE | ID: mdl-39854413

RESUMO

BACKGROUND: Intestinal transplantation (ITx) represents the only curative option for patients with irreversible intestinal failure. Nevertheless, its rejection rate surpasses that of other solid organ transplants due to the heightened immunological load of the gut. Regulatory T-cells (Tregs) are key players in the induction and maintenance of peripheral tolerance, suggesting their potential involvement in modulating host vs. graft responses after ITx. Thus, we investigated the association of Tregs with allograft outcomes in pediatric patients and in an experimental model of small bowel transplantation. METHODS: Treg frequency in human samples was analyzed by Flow cytometry (CD4+CD25highCD127-, blood samples) and immunohistochemistry (FoxP3, graft samples). Experimental allogenic-heterotopic small bowel transplantation was performed in rats and animals divided into 3 groups: non-immunosuppressant treatment, rapamycin (2 mg/kg), and tacrolimus (0.6 mg/kg) treatment. Acute cellular rejection (ACR) was diagnosed based on clinical and histological findings, graft gene expression of pro- and anti-inflammatory mediators assessed by RT-qPCR, serum IL-6 and IL-10 levels by Luminex, and Treg frequency analyzed by flow cytometry (CD4+CD25highFoxP3+). RESULTS: Blood samples from patients undergoing ACR exhibited a significant reduction in the Treg number compared to those with normo-functional grafts. Similarly, a diminished number of FoxP3+ cells was observed in mucosa samples with ACR. In the experimental model, rapamycin-treated animals displayed clinical and histological findings resembling those not receiving immunosuppression treatment. Notably, ACR correlated with a high CD8/CD4 ratio, loss of T-cell chimerism, mRNA upregulation of pro-inflammatory genes and diminished graft Treg frequency. In contrast, tacrolimus treatment prevented ACR and facilitate blood and graft Treg expansion. Remarkably, recipients who achieved Treg expansion within the graft remained free of ACR even after discontinuation of the immunosuppressant treatment and this phenomenon was associated with increased levels of serum IL-10. CONCLUSION: Our clinical and experimental findings underscore the association between Treg frequency and graft rejection after ITx, advocating for strategies that promote their expansion within the gut mucosa to enhance long-term outcomes.


Assuntos
Rejeição de Enxerto , Intestino Delgado , Linfócitos T Reguladores , Linfócitos T Reguladores/imunologia , Rejeição de Enxerto/imunologia , Animais , Intestino Delgado/transplante , Intestino Delgado/imunologia , Humanos , Masculino , Ratos , Feminino , Criança , Adolescente , Pré-Escolar , Imunossupressores/uso terapêutico , Tacrolimo/uso terapêutico , Tacrolimo/farmacologia , Sirolimo/farmacologia , Sirolimo/uso terapêutico
2.
Pharmacol Biochem Behav ; 245: 173893, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39419355

RESUMO

Memory persistence is a crucial aspect of long-term memory (LTM) and involves late consolidation processes that modulate memory stability over time. Acute physical exercise (PE) has emerged as a potential strategy to modulate memory consolidation and enhance memory persistence. While its effects have been extensively explored in the early consolidation phase, its impact on the late phase remains unexplored. In this study, we investigated the effects and mechanisms of an acute PE on the late consolidation window of novel object recognition (NOR) memory in rats. A 30-minute running session applied 11 h after NOR memory acquisition significantly increased memory persistence for at least 7 days. The inhibition of hippocampal protein synthesis immediately after acute PE using anisomycin (a ribosomal inhibitor) or rapamycin (an mTOR pathway inhibitor) impaired the effect of PE on memory persistence. Animals only presented memory 1 day after acquisition. The same effect was observed with the inhibition of beta-adrenergic receptors by timolol. Although there were no differences between the groups' comparison, blocking D1/D5 receptors after acute PE resulted in a lack of memory persistence in the dichotomous testing (remember/non-remember). Therefore, our exploration of the mechanisms underlying this enhancement revealed the involvement of protein synthesis and the requirement of beta-adrenergic and dopaminergic D1/D5 receptors in the dorsal hippocampus. These findings provide valuable insights into PE as a potential memory modulator, contributing to expanding our understanding of memory consolidation dynamics and acute PE effects.


Assuntos
Anisomicina , Hipocampo , Consolidação da Memória , Condicionamento Físico Animal , Ratos Wistar , Animais , Masculino , Hipocampo/metabolismo , Hipocampo/efeitos dos fármacos , Ratos , Condicionamento Físico Animal/fisiologia , Consolidação da Memória/efeitos dos fármacos , Consolidação da Memória/fisiologia , Anisomicina/farmacologia , Catecolaminas/metabolismo , Catecolaminas/biossíntese , Biossíntese de Proteínas/efeitos dos fármacos , Reconhecimento Psicológico/efeitos dos fármacos , Sirolimo/farmacologia , Timolol/farmacologia , Timolol/administração & dosagem , Memória/efeitos dos fármacos , Memória de Longo Prazo/efeitos dos fármacos
3.
Inflamm Res ; 73(11): 1995-2008, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39340660

RESUMO

OBJECTIVES: Investigate whether and which synoviocytes would acquire trained immunity characteristics that could exacerbate joint inflammation following a secondary Staphylococcus aureus infection. METHODS: Lipopolysaccharide (LPS) and S. aureus were separately or double injected (21 days of interval) into the tibiofemoral joint cavity of male C57BL/6 mice. At different time points after these stimulations, mechanical nociception was analyzed followed by the analysis of signs of inflammation and damage in the affected joints. The trained immunity markers, including the glycolytic and mTOR pathway, were analyzed in whole tissue or isolated synoviocytes. A group of mice was treated with Rapamycin, an mTOR inhibitor before LPS or S. aureus stimulation. RESULTS: The double LPS - S. aureus hit promoted intense joint inflammation and damage compared to single joint stimulation, including markers in synoviocyte activation, production of proinflammatory cytokines, persistent nociception, and bone damage, despite not reducing the bacterial clearance. The double LPS - S. aureus hit joints increased the synovial macrophage population expressing CX3CR1 alongside triggering established epigenetic modifications associated with trained immunity events in these cells, such as the upregulation of the mTOR signaling pathway (p-mTOR and HIF1α) and the trimethylation of histone H3. Mice treated with Rapamycin presented reduced CX3CR1+ macrophage activation, joint inflammation, and bone damage. CONCLUSIONS: There is a trained immunity phenotype in CX3CR1+ synovial macrophages that contributes to the exacerbation of joint inflammation and damage during septic arthritis caused by S. aureus.


Assuntos
Lipopolissacarídeos , Macrófagos , Camundongos Endogâmicos C57BL , Infecções Estafilocócicas , Staphylococcus aureus , Serina-Treonina Quinases TOR , Animais , Masculino , Infecções Estafilocócicas/imunologia , Macrófagos/imunologia , Serina-Treonina Quinases TOR/imunologia , Staphylococcus aureus/imunologia , Receptor 1 de Quimiocina CX3C/metabolismo , Membrana Sinovial/imunologia , Membrana Sinovial/patologia , Artrite Infecciosa/imunologia , Artrite Infecciosa/microbiologia , Camundongos , Citocinas/imunologia , Citocinas/metabolismo , Sirolimo/farmacologia , Inflamação/imunologia , Sinoviócitos/imunologia , Sinoviócitos/efeitos dos fármacos , Nociceptividade/efeitos dos fármacos , Imunidade Treinada
4.
Acta Cir Bras ; 39: e397324, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39258620

RESUMO

PURPOSE: To compare the endothelial coverage of different stents in porcine carotid arteries. Research problem: How effective are polyurethane stents (PU) and PU + rapamycin (PU + RAPA) compared to bare-metal stents on endothelial coverage by neointima in pigs after 28 days? METHODS: The methodology had two phases for an interventional, experimental, prospective study, with three Moura pigs, 12 weeks old and weighing between 19 and 22.5 kg. In phase I, eight stents were implanted in carotid arteries; three stents coated with PU, three coated with PU + RAPA, and two without coating. After 28 days, phase II was carried out, consisting of euthanasia, removal of the stents, to evaluate the exposed area of the stent struts, and the percentage of endothelialization through optical microscopy and scanning electron microscopy. RESULTS: The eight stents implanted with ultrasound sizing and post-dilation with a larger diameter balloon were analyzed by Doppler ultrasound, intravascular ultrasound, and angiography after 28 days. CONCLUSIONS: This study showed complete endothelial coverage by the endoluminal neointima of the stent struts, good integration and coverage with the arterial wall, with no exposed struts showing the presence of intimal hyperplasia (whitish tissue).


Assuntos
Stents Farmacológicos , Sirolimo , Animais , Sirolimo/administração & dosagem , Sirolimo/farmacologia , Suínos , Artérias Carótidas/cirurgia , Artérias Carótidas/efeitos dos fármacos , Neointima/patologia , Microscopia Eletrônica de Varredura , Poliuretanos , Estudos Prospectivos , Endotélio Vascular/efeitos dos fármacos , Reprodutibilidade dos Testes , Polímeros , Modelos Animais , Fatores de Tempo , Materiais Revestidos Biocompatíveis
5.
Int J Mol Sci ; 25(13)2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-39000270

RESUMO

The combination of a polyphenol, quercetin, with dasatinib initiated clinical trials to evaluate the safety and efficacy of senolytics in idiopathic pulmonary fibrosis, a lung disease associated with the presence of senescent cells. Another approach to senotherapeutics consists of controlling inflammation related to cellular senescence or "inflammaging", which participates, among other processes, in establishing pulmonary fibrosis. We evaluate whether polyphenols such as caffeic acid, chlorogenic acid, epicatechin, gallic acid, quercetin, or resveratrol combined with different senotherapeutics such as metformin or rapamycin, and antifibrotic drugs such as nintedanib or pirfenidone, could present beneficial actions in an in vitro model of senescent MRC-5 lung fibroblasts. A senescent-associated secretory phenotype (SASP) was evaluated by the measurement of interleukin (IL)-6, IL-8, and IL-1ß. The senescent-associated ß-galactosidase (SA-ß-gal) activity and cellular proliferation were assessed. Fibrosis was evaluated using a Picrosirius red assay and the gene expression of fibrosis-related genes. Epithelial-mesenchymal transition (EMT) was assayed in the A549 cell line exposed to Transforming Growth Factor (TGF)-ß in vitro. The combination that demonstrated the best results was metformin and caffeic acid, by inhibiting IL-6 and IL-8 in senescent MRC-5 cells. Metformin and caffeic acid also restore cellular proliferation and reduce SA-ß-gal activity during senescence induction. The collagen production by senescent MRC-5 cells was inhibited by epicatechin alone or combined with drugs. Epicatechin and nintedanib were able to control EMT in A549 cells. In conclusion, caffeic acid and epicatechin can potentially increase the effectiveness of senotherapeutic drugs in controlling lung diseases whose pathophysiological component is the presence of senescent cells and fibrosis.


Assuntos
Senescência Celular , Fibroblastos , Pulmão , Polifenóis , Humanos , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Senescência Celular/efeitos dos fármacos , Polifenóis/farmacologia , Pulmão/patologia , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Células A549 , Proliferação de Células/efeitos dos fármacos , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Metformina/farmacologia , Ácidos Cafeicos/farmacologia , Indóis/farmacologia , Senoterapia/farmacologia , Linhagem Celular , Fenótipo Secretor Associado à Senescência/efeitos dos fármacos , Sirolimo/farmacologia , Interleucina-8/metabolismo , Interleucina-8/genética , Fator de Crescimento Transformador beta/metabolismo , Piridonas
6.
BMC Cancer ; 24(1): 853, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39026155

RESUMO

BACKGROUND: Metformin, a widely prescribed antidiabetic drug, has shown several promising effects for cancer treatment. These effects have been shown to be mediated by dual modulation of the AMPK-mTORC1 axis, where AMPK acts upstream of mTORC1 to decrease its activity. Nevertheless, alternative pathways have been recently discovered suggesting that metformin can act through of different targets regulation. METHODS: We performed a transcriptome screening analysis using HeLa xenograft tumors generated in NOD-SCID mice treated with or without metformin to examine genes regulated by metformin. Western Blot analysis, Immunohistochemical staining, and RT-qPCR were used to confirm alterations in gene expression. The TNMplot and GEPIA2 platform were used for in silico analysis of genes found up-regulated by metformin, in cervical cancer patients. We performed an AMPK knock-down using AMPK-targeted siRNAs and mTOR inhibition with rapamycin to investigate the molecular mechanisms underlying the effect of metformin in cervical cancer cell lines. RESULTS: We shown that metformin decreases tumor growth and increased the expression of a group of antitumoral genes involved in DNA-binding transcription activator activity, hormonal response, and Dcp1-Dcp2 mRNA-decapping complex. We demonstrated that ZFP36 could act as a new molecular target increased by metformin. mTORC1 inhibition using rapamycin induces ZFP36 expression, which could suggest that metformin increases ZFP36 expression and requires mTORC1 inhibition for such effect. Surprisingly, in HeLa cells AMPK inhibition did not affect ZFP36 expression, suggesting that additional signal transducers related to suppressing mTORC1 activity, could be involved. CONCLUSIONS: These results highlight the importance of ZFP36 activation in response to metformin treatment involving mTORC1 inhibition.


Assuntos
Alvo Mecanístico do Complexo 1 de Rapamicina , Metformina , Neoplasias do Colo do Útero , Ensaios Antitumorais Modelo de Xenoenxerto , Humanos , Metformina/farmacologia , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/antagonistas & inibidores , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/genética , Feminino , Animais , Camundongos , Células HeLa , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Camundongos SCID , Camundongos Endogâmicos NOD , Proliferação de Células/efeitos dos fármacos , Linhagem Celular Tumoral , Transdução de Sinais/efeitos dos fármacos , Sirolimo/farmacologia
7.
Neurochem Int ; 176: 105740, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38636905

RESUMO

The benefits of physical exercise (PE) on memory consolidation have been well-documented in both healthy and memory-impaired animals. However, the underlying mechanisms through which PE exerts these effects are still unclear. In this study, we aimed to investigate the role of hippocampal protein synthesis in memory modulation by acute PE in rats. After novel object recognition (NOR) training, rats were subjected to a 30-min moderate-intensity acute PE on the treadmill, while control animals did not undergo any procedures. Using anisomycin (ANI) and rapamycin (RAPA), compounds that inhibit protein synthesis through different mechanisms, we manipulated protein synthesis in the CA1 region of the hippocampus to examine its contribution to memory consolidation. Memory was assessed on days 1, 7, and 14 post-training. Our results showed that inhibiting protein synthesis by ANI or RAPA impaired NOR memory consolidation in control animals. However, acute PE prevented this impairment without affecting memory persistence. We also evaluated brain-derived neurotrophic factor (BDNF) levels after acute PE at 0.5h, 2h, and 12h afterward and found no differences in levels compared to animals that did not engage in acute PE or were only habituated to the treadmill. Therefore, our findings suggest that acute PE could serve as a non-pharmacological intervention to enhance memory consolidation and prevent memory loss in conditions associated with hippocampal protein synthesis inhibition. This mechanism appears not to depend on BDNF synthesis in the early hours after exercise.


Assuntos
Amnésia , Anisomicina , Fator Neurotrófico Derivado do Encéfalo , Hipocampo , Condicionamento Físico Animal , Ratos Wistar , Animais , Masculino , Condicionamento Físico Animal/fisiologia , Ratos , Hipocampo/metabolismo , Hipocampo/efeitos dos fármacos , Anisomicina/farmacologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/biossíntese , Amnésia/metabolismo , Amnésia/prevenção & controle , Inibidores da Síntese de Proteínas/farmacologia , Sirolimo/farmacologia , Biossíntese de Proteínas/efeitos dos fármacos , Biossíntese de Proteínas/fisiologia , Consolidação da Memória/efeitos dos fármacos , Consolidação da Memória/fisiologia , Reconhecimento Psicológico/efeitos dos fármacos , Reconhecimento Psicológico/fisiologia
8.
Front Immunol ; 15: 1310505, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38515742

RESUMO

Aging is a complex, natural, and irreversible phenomenon that subjects the body to numerous changes in the physiological process, characterized by a gradual decline in the organism's homeostatic mechanisms, closely related to immunosenescence. Here, we evaluated the regulation of immunosenescence in lymphoid organs of senescence-accelerated prone 8 (SAM-P8) and senescence-accelerated resistant 1 (SAM-R1) mice treated with a low dose of rapamycin (RAPA). Mice were treated with a dose of 7.1 µg/kg RAPA for 2 months and had body mass and hematological parameters analyzed prior and during treatment. Cellular and humoral parameters of serum, bone marrow, thymus, and spleen samples were evaluated by ELISA, histology, and flow cytometry. Changes in body mass, hematological parameters, cell number, and in the secretion of IL-1ß, IL-6, TNF-α, IL-7, and IL-15 cytokines were different between the 2 models used. In histological analyses, we observed that SAM-P8 mice showed faster thymic involution than SAM-R1 mice. Regarding the T lymphocyte subpopulations in the spleen, CD4+ and CD8+ T cell numbers were higher and lower, respectively, in SAM-P8 mice treated with RAPA, with the opposite observed in SAM-R1. Additionally, we found that the low dose of RAPA used did not trigger changes that could compromise the immune response of these mice and the administered dose may have contributed to changes in important lymphocyte populations in the adaptive immune response and the secretion of cytokines that directly collaborate with the maturation and proliferation of these cells.


Assuntos
Envelhecimento , Sirolimo , Camundongos , Humanos , Animais , Sirolimo/farmacologia , Subpopulações de Linfócitos T , Linfócitos T CD8-Positivos , Citocinas
9.
New Phytol ; 241(5): 2039-2058, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38191763

RESUMO

Mitochondrial function is essential for plant growth, but the mechanisms involved in adjusting growth and metabolism to changes in mitochondrial energy production are not fully understood. We studied plants with reduced expression of CYTC-1, one of two genes encoding the respiratory chain component cytochrome c (CYTc) in Arabidopsis, to understand how mitochondria communicate their status to coordinate metabolism and growth. Plants with CYTc deficiency show decreased mitochondrial membrane potential and lower ATP content, even when carbon sources are present. They also exhibit higher free amino acid content, induced autophagy, and increased resistance to nutritional stress caused by prolonged darkness, similar to plants with triggered starvation signals. CYTc deficiency affects target of rapamycin (TOR)-pathway activation, reducing S6 kinase (S6K) and RPS6A phosphorylation, as well as total S6K protein levels due to increased protein degradation via proteasome and autophagy. TOR overexpression restores growth and other parameters affected in cytc-1 mutants, even if mitochondrial membrane potential and ATP levels remain low. We propose that CYTc-deficient plants coordinate their metabolism and energy availability by reducing TOR-pathway activation as a preventive signal to adjust growth in anticipation of energy exhaustion, thus providing a mechanism by which changes in mitochondrial activity are transduced to the rest of the cell.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Citocromos c/genética , Citocromos c/metabolismo , Sirolimo/farmacologia , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas Quinases S6 Ribossômicas/metabolismo , Trifosfato de Adenosina/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo
10.
Arch Oral Biol ; 157: 105840, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37939517

RESUMO

OBJECTIVE: Emerging evidence suggests that the modest response of head and neck squamous cell carcinoma (HNSCC) to treatment is associated with cancer stem cells (CSC). However, the signaling pathways that play a role in HNSCC CSC maintenance and therapy response are not well-understood. In this study, we investigate the response of CSCs to phosphatase and tensin homolog (PTEN) modulation and its potential dependency on the mammalian target of rapamycin (mTOR) signaling. DESIGN: PTEN deficiency was stably induced using short hairpin RNA (shRNA). Downregulation of RPTOR/mTORC1 and RICTOR/mTORC2 was achieved using small interfering RNA (siRNA). CSCs were evaluated through tumorsphere formation and were classified into various subtypes: parasphere, merosphere, and holosphere. We investigated the effect of rapamycin on CSC properties in both control and PTEN-deficient HNSCC cells. RESULTS: PTEN deficiency led to an accumulation of CSCs and enhanced a favorable response to rapamycin treatment. The viability of HNSCC CSCs was dependent on mTOR signaling. Deficiencies in both mTORC1 and mTORC2 reduced the number of CSCs. However, CSCs with PTEN deficiency had a greater reliance on mTORC1 signaling. Interestingly, when considering CSC subtypes, a deficiency in mTORC2 led to an increased number of paraspheres in both the control and PTEN-deficient groups. CONCLUSIONS: Loss of PTEN signaling increased the HNSCC CSC population, which can be targeted by rapamycin. However, the mTORC2 deficiency can induce a problematic selection of paraspheres CSCs subtype.


Assuntos
Neoplasias de Cabeça e Pescoço , Sirolimo , Humanos , Alvo Mecanístico do Complexo 2 de Rapamicina/genética , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Sirolimo/farmacologia , Carcinoma de Células Escamosas de Cabeça e Pescoço , Serina-Treonina Quinases TOR , Células-Tronco/metabolismo
11.
Future Microbiol ; 18: 1061-1075, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37721517

RESUMO

Background: Cryptococcus neoformans is an opportunistic fungal pathogen that causes infections mainly in immunosuppressed individuals, such as transplant recipients. Aims: This study investigated the effects of rapamycin, an immunosuppressant drug, on the cellular organization, biophysical characteristics, and main virulence factors of C. neoformans. Methods: Morphological, structural, physicochemical and biophysical analyses of cells and secreted polysaccharides of the reference H99 C. neoformans strain were investigated under the effect of subinhibitory concentrations of rapamycin. Results: Rapamycin at a minimum inhibitory concentration of 2.5 µM reduced C. neoformans cell viability by 53%, decreased capsule, increased cell size, chitin and lipid body formation, and changed peptidase and urease activity. Conclusion: Further studies are needed to assess how rapamycin affects the virulence factors and pathogenicity of C. neoformans.


Cryptococcosis is a fungal infection caused by a type of fungus called Cryptococcus. Among the Cryptococcus group, Cryptococcus neoformans is often linked to fungal infections in people who have a weak immune system (known as being immunosuppressed). The main aim of this work was to look at the effect of an immunosuppressant called rapamycin, which is commonly used to prevent organ transplant rejection, on the ability of C. neoformans to cause infection. The results showed that this drug stopped the growth of the fungus, dampening its ability to cause disease.


Assuntos
Criptococose , Cryptococcus neoformans , Humanos , Fatores de Virulência , Sirolimo/farmacologia , Criptococose/microbiologia , Virulência
12.
Int J Mol Sci ; 24(15)2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37569368

RESUMO

TOR proteins, also known as targets of rapamycin, are serine/threonine kinases involved in various signaling pathways that regulate cell growth. The protozoan parasite Giardia lamblia is the causative agent of giardiasis, a neglected infectious disease in humans. In this study, we used a bioinformatics approach to examine the structural features of GTOR, a G. lamblia TOR-like protein, and predict functional associations. Our findings confirmed that it shares significant similarities with functional TOR kinases, including a binding domain for the FKBP-rapamycin complex and a kinase domain resembling that of phosphatidylinositol 3-kinase-related kinases. In addition, it can form multiprotein complexes such as TORC1 and TORC2. These results provide valuable insights into the structure-function relationship of GTOR, highlighting its potential as a molecular target for controlling G. lamblia cell proliferation. Furthermore, our study represents a step toward rational drug design for specific anti-giardiasis therapeutic agents.


Assuntos
Giardia lamblia , Giardíase , Humanos , Sirolimo/farmacologia , Giardia lamblia/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Transdução de Sinais , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo
13.
World J Urol ; 41(9): 2375-2380, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37470811

RESUMO

PURPOSE: To understand the effect of Nitazoxanide (NTZ), Rapamycin, Thalidomide, alone and in combination with BCG on bladder cancer (BC) histopathology and programmed death-ligand 1 (PD-L1) and anti-cytotoxic T lymphocyte antigen 4 (CTLA4) expression. METHODS: Female Fisher-344 rats underwent intravesical N-methyl-N-nitrosourea (MNU) followed by weekly intravesical treatment with saline (controls, n = 10), BCG (n = 10), NTZ (n = 8), BCG plus NTZ (n = 8), Rapamycin (n = 10) BCG plus Rapamycin (n = 10), Thalidomide (n = 10), and BCG plus Thalidomide (n = 10), and euthanized after 8 weeks and their bladders were investigated for BC and PD-L1 and CTLA4 expression. RESULTS: Rapamicyn alone and in combination with BCG had the lowest number of bladder neoplasias in the histopathology exam (1/10). Neoplastic lesions were found in 4/10 BCG recipients, 5/10 Thalidomide recipients, 4/10 Thalidomide plus BCG recipients, 5/8 NTZ and 3/8 NTZ plus BCG recipients. Adding NTZ to BCG increased the expression of PD-L1 and adding Rapamycin or Thalidomide decreased PD-L1 and CTLA4 expression compared to BCG alone. Rapamycin alone significantly increased CTLA4 and slightly increased PD-L1 expression but its combination with BCG significantly decreased both markers. Thalidomide had a similar effect; however, it was only slightly different from the control and BCG alone groups. CONCLUSION: Intravesical BCG combination treatment seems to effectively prevent BC development in an immunecompetent clinically relevant animal model, introducing Thalidomide, Nitazoxanide, and specially Rapamycin as candidates in the intravesical immunotherapy advancement. Our study contributes in understanding the mechanism of cancer immunotherapy.


Assuntos
Talidomida , Neoplasias da Bexiga Urinária , Ratos , Feminino , Animais , Talidomida/farmacologia , Talidomida/uso terapêutico , Vacina BCG/uso terapêutico , Antígeno B7-H1 , Antígeno CTLA-4 , Sirolimo/farmacologia , Sirolimo/uso terapêutico , Neoplasias da Bexiga Urinária/patologia , Administração Intravesical , Adjuvantes Imunológicos/uso terapêutico
14.
Biol Res ; 56(1): 41, 2023 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-37438828

RESUMO

BACKGROUND: Hyperbaric oxygen treatment (HBOT) has been reported to modulate the proliferation of neural and mesenchymal stem cell populations, but the molecular mechanisms underlying these effects are not completely understood. In this study, we aimed to assess HBOT somatic stem cell modulation by evaluating the role of the mTOR complex 1 (mTORC1), a key regulator of cell metabolism whose activity is modified depending on oxygen levels, as a potential mediator of HBOT in murine intestinal stem cells (ISCs). RESULTS: We discovered that acute HBOT synchronously increases the proliferation of ISCs without affecting the animal's oxidative metabolism through activation of the mTORC1/S6K1 axis. mTORC1 inhibition by rapamycin administration for 20 days also increases ISCs proliferation, generating a paradoxical response in mice intestines, and has been proposed to mimic a partial starvation state. Interestingly, the combination of HBOT and rapamycin does not have a synergic effect, possibly due to their differential impact on the mTORC1/S6K1 axis. CONCLUSIONS: HBOT can induce an increase in ISCs proliferation along with other cell populations within the crypt through mTORC1/S6K1 modulation without altering the oxidative metabolism of the animal's small intestine. These results shed light on the molecular mechanisms underlying HBOT therapeutic action, laying the groundwork for future studies.


Assuntos
Oxigenoterapia Hiperbárica , Transdução de Sinais , Células-Tronco , Animais , Camundongos , Proliferação de Células , Intestinos/citologia , Alvo Mecanístico do Complexo 1 de Rapamicina , Oxigênio , Sirolimo/farmacologia , Células-Tronco/efeitos dos fármacos
15.
Nanomedicine (Lond) ; 18(10): 789-801, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37199266

RESUMO

Aims: The development of rapamycin (RAP) and resveratrol (RSV) coloaded liposomes (RAP-RSV-LIP) for breast cancer therapy. Materials & methods: Liposomes were prepared using a high-pressure homogenization technique and evaluated according to their physicochemical characteristics, cellular uptake and cytotoxicity against tumoral and normal cells. Results & conclusion: The RAP-RSV-LIP showed negative surface charge, size around 100 nm, low polydispersity and high encapsulation efficiency for RAP and RSV (58.87 and 63.22%, respectively). RAP-RSV-LIP showed great stability over 60 days and a prolonged drug-release profile. In vitro studies indicated that RAP-RSV-LIP were internalized in an estrogen receptor-positive human breast cancer cell line (MCF-7, 34.2%) and improved cytotoxicity when compared with free drugs. Therefore RAP-RSV-LIP showed great antitumoral potential against breast cancer cells.


Assuntos
Neoplasias da Mama , Lipossomos , Humanos , Feminino , Resveratrol/farmacologia , Lipossomos/uso terapêutico , Sirolimo/farmacologia , Sirolimo/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Antioxidantes/uso terapêutico , Linhagem Celular Tumoral
16.
Pharmacol Res ; 183: 106403, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35987481

RESUMO

The serine/threonine kinase Akt is a major player in the phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling pathway, and its modulation impacts multiple cellular processes such as growth, proliferation, and survival. Several abnormalities in this pathway have been documented over the years, and these alterations were shown to have great implications in tumorigenesis and resistance to chemotherapy. Thus, multiple Akt inhibitors have been developed and tested in adult tumors, and some of them are currently undergoing phase I, II, and III clinical trials for distinct cancers that arise during adulthood. Despite that, the impact of these inhibitors is still not fully understood in pediatric tumors, and Akt-specific targeting seems to be a promising approach to treat children affected by cancers. This review summarizes recent available evidence of Akt inhibitors in pediatric cancers, from both preclinical and clinical studies. In short, we demonstrate the impact that Akt inhibition provides in tumorigenesis, and we suggest targeting the PI3K/Akt/mTOR signaling pathway, alone or in combination with other inhibitors, is a feasible tool to achieve better outcomes in pediatric tumors.


Assuntos
Neoplasias , Fosfatidilinositol 3-Quinases , Adulto , Carcinogênese , Criança , Humanos , Neoplasias/tratamento farmacológico , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/metabolismo
18.
Clin Exp Pharmacol Physiol ; 49(8): 893-902, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35637552

RESUMO

Regular endurance exercise is a non-pharmacological strategy to protect the liver against diseases. Conversely, exercise may be harmful when excessive, the so-called overtraining. As expected, mice who underwent an overtraining protocol presented higher levels of proinflammatory cytokines in the serum and liver. Based on the relationship among overtraining, inflammation and mammalian target of rapamycin complex 1 (mTORC1) upregulation, the present study verified if animals submitted to an overtraining protocol, but with inhibition of the mTOR pathway via rapamycin injections could mitigate the liver and serum inflammation. Once autophagy can be linked to the improvement of hepatic dysfunction, we also investigated if the inhibition of mTORC1 by rapamycin can improve hepatic autophagy. The animals were randomized into four groups: control (CT; sedentary mice), overtraining by downhill running (OT; mice submitted to the downhill running-based overtraining protocol), overtraining by downhill running with chronic administration of rapamycin (OT/Rapa; mice submitted to the downhill running-based overtraining protocol with intraperitoneal injections of rapamycin) and aerobic (AER; submitted to aerobic training protocol). The serum and liver of the animals were used for biochemical analysis, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and immunoblotting. The main results are (a) OT and OT/Rapa protocols decreased the performance; (b) the protein levels of interleukin 6 (IL-6) were higher for the OT group; the OT/Rapa group reduced the autophagic genes, increased the microtubule-associated protein light chain 3 II/I (LC3II/LC3I) protein ratio and decreased the sequestosome 1 (SQSTM1) protein. In conclusion, rapamycin appears efficiently to increase the autophagy proteins and decrease IL-6 protein in the liver of overtraining mice.


Assuntos
Interleucina-6 , Sirolimo , Animais , Autofagia , Inflamação/metabolismo , Mamíferos/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos , Proteínas Associadas aos Microtúbulos/metabolismo , Sirolimo/farmacologia
19.
FEBS Open Bio ; 12(8): 1509-1522, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35538662

RESUMO

DNA damage induces the activation of many different signals associated with repair or cell death, but it is also connected with physiological events, such as adult neurogenesis and B-cell differentiation. DNA damage induces different signaling pathways, some of them linked to important metabolic changes. The mTORC1 pathway has a central role in the regulation of growth processes and cell division in response to environmental changes and also controls protein synthesis, lipid biogenesis, nucleotide synthesis, and expression of glycolytic genes. Here, we report that double-strand breaks induced with etoposide affect the expression of genes encoding different enzymes associated with specific metabolic pathways in Ramos cells. We also analyzed the role of mTOR signaling, demonstrating that double-strand breaks induce downregulation of mTOR signaling. Specific inhibition of mTORC1 using rapamycin also induced changes in the expression of metabolic genes. Finally, we demonstrated that DNA damage and rapamycin can regulate glucose uptake. In summary, our findings show that etoposide and rapamycin affect the expression of metabolic genes as well as apoptotic and proliferation markers in Ramos cells, increasing our understanding of cancer metabolism.


Assuntos
Dano ao DNA , Serina-Treonina Quinases TOR , Etoposídeo/farmacologia , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/metabolismo
20.
J Interferon Cytokine Res ; 42(4): 153-160, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35384725

RESUMO

Rapamycin is an immunomodulatory drug that has been evaluated in preclinical and clinical trials as a disease-modifying therapy for multiple sclerosis (MS). In this study, we evaluated the in vitro effect of rapamycin on immune cells pivotally involved in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), which is an animal model to study MS. Splenocytes and central nervous system (CNS)-mononuclear cells obtained from EAE mice were stimulated with a myelin oligodendrocyte glycoprotein peptide, whereas the microglial BV-2 cell line was activated with LPS. The 3 immune cell types were simultaneously treated with rapamycin, incubated, and then used to analyze cytokines, transcription factors, and activation markers. Rapamycin reduced IL-17 production, TBX21, and RORc expression by splenic and CNS cell cultures. IFN-γ and TNF-α production were also decreased in CNS cultures. This treatment also decreased TNF-α, IL-6, MHC II, CD40, and CD86 expression by BV-2 cells. These results indicated that in vivo immunomodulatory activity of rapamycin in MS and EAE was, in many aspects, reproduced by in vitro assays done with cells derived from the spleen and the CNS of EAE mice. This procedure could constitute a screening strategy for choosing drugs with therapeutic potential for MS.


Assuntos
Encefalomielite Autoimune Experimental , Esclerose Múltipla , Animais , Citocinas/metabolismo , Encefalomielite Autoimune Experimental/tratamento farmacológico , Encefalomielite Autoimune Experimental/metabolismo , Lipopolissacarídeos/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Microglia/metabolismo , Microglia/patologia , Fragmentos de Peptídeos/metabolismo , Fragmentos de Peptídeos/farmacologia , Sirolimo/metabolismo , Sirolimo/farmacologia , Sirolimo/uso terapêutico , Fator de Necrose Tumoral alfa/metabolismo
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