Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 8.442
Filtrar
1.
Biol Direct ; 19(1): 26, 2024 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-38582839

RESUMO

Ischemic stroke is a sudden and acute disease characterized by neuronal death, increment of reactive gliosis (reactive microglia and astrocytes), and a severe inflammatory process. Neuroinflammation is an early event after cerebral ischemia, with microglia playing a leading role. Reactive microglia involve functional and morphological changes that drive a wide variety of phenotypes. In this context, deciphering the molecular mechanisms underlying such reactive microglial is essential to devise strategies to protect neurons and maintain certain brain functions affected by early neuroinflammation after ischemia. Here, we studied the role of mammalian target of rapamycin (mTOR) activity in the microglial response using a murine model of cerebral ischemia in the acute phase. We also determined the therapeutic relevance of the pharmacological administration of rapamycin, a mTOR inhibitor, before and after ischemic injury. Our data show that rapamycin, administered before or after brain ischemia induction, reduced the volume of brain damage and neuronal loss by attenuating the microglial response. Therefore, our findings indicate that the pharmacological inhibition of mTORC1 in the acute phase of ischemia may provide an alternative strategy to reduce neuronal damage through attenuation of the associated neuroinflammation.


Assuntos
Isquemia Encefálica , Microglia , Camundongos , Animais , Alvo Mecanístico do Complexo 1 de Rapamicina , Doenças Neuroinflamatórias , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/genética , Serina-Treonina Quinases TOR/uso terapêutico , Isquemia , Sirolimo/farmacologia , Sirolimo/uso terapêutico , Mamíferos
2.
Neuromolecular Med ; 26(1): 10, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38570425

RESUMO

The manifestations of tuberous sclerosis complex (TSC) in humans include epilepsy, autism spectrum disorders (ASD) and intellectual disability. Previous studies suggested the linkage of TSC to altered cerebral blood flow and metabolic dysfunction. We previously reported a significant elevation in cerebral blood flow in an animal model of TSC and autism of young Eker rats. Inhibition of the mammalian target of rapamycin (mTOR) by rapamycin could restore normal oxygen consumption and cerebral blood flow. In this study, we investigated whether inhibiting a component of the mTOR signaling pathway, p70 ribosomal S6 kinase (S6K1), would yield comparable effects. Control Long Evans and Eker rats were divided into vehicle and PF-4708671 (S6K1 inhibitor, 75 mg/kg for 1 h) treated groups. Cerebral regional blood flow (14C-iodoantipyrine) was determined in isoflurane anesthetized rats. We found significantly increased basal cortical (+ 32%) and hippocampal (+ 15%) blood flow in the Eker rats. PF-4708671 significantly lowered regional blood flow in the cortex and hippocampus of the Eker rats. PF-4708671 did not significantly lower blood flow in these regions in the control Long Evans rats. Phosphorylation of S6-Ser240/244 and Akt-Ser473 was moderately decreased in Eker rats but only the latter reached statistical significance upon PF-4708671 treatment. Our findings suggest that moderate inhibition of S6K1 with PF-4708671 helps to restore normal cortical blood flow in Eker rats and that this information might have therapeutic potential in tuberous sclerosis complex and autism.


Assuntos
Transtorno Autístico , Esclerose Tuberosa , Animais , Humanos , Ratos , Transtorno Autístico/tratamento farmacológico , Transtorno Autístico/metabolismo , Mamíferos/metabolismo , Fosforilação , Ratos Long-Evans , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/uso terapêutico , Sirolimo/farmacologia , Serina-Treonina Quinases TOR , Esclerose Tuberosa/tratamento farmacológico , Esclerose Tuberosa/metabolismo
3.
Front Immunol ; 15: 1367048, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38585259

RESUMO

Objective: In the defense against microorganisms like Candida albicans, macrophages recruit LC3(Microtubule-associated protein 1A/1B-light chain 3) to the periplasm, engaging in the elimination process through the formation of a single-membrane phagosome known as LC3-associated phagocytosis (LAP). Building on this, we propose the hypothesis that glucocorticoids may hinder macrophage phagocytosis of Candida glabrata by suppressing LAP, and rapamycin could potentially reverse this inhibitory effect. Methods: RAW264.7 cells were employed for investigating the immune response to Candida glabrata infection. Various reagents, including dexamethasone, rapamycin, and specific antibodies, were utilized in experimental setups. Assays, such as fluorescence microscopy, flow cytometry, ELISA (Enzyme-Linked Immunosorbent Assay), Western blot, and confocal microscopy, were conducted to assess phagocytosis, cytokine levels, protein expression, viability, and autophagy dynamics. Results: Glucocorticoids significantly inhibited macrophage autophagy, impairing the cells' ability to combat Candida glabrata. Conversely, rapamycin exhibited a dual role, initially inhibiting and subsequently promoting phagocytosis of Candida glabrata by macrophages. Glucocorticoids hinder macrophage autophagy in Candida glabrata infection by suppressing the MTOR pathway(mammalian target of rapamycin pathway), while the activation of MTOR pathway by Candida glabrata diminishes over time. Conclusion: Our study elucidates the intricate interplay between glucocorticoids, rapamycin, and macrophage autophagy during Candida glabrata infection. Understanding the implications of these interactions not only sheds light on the host immune response dynamics but also unveils potential therapeutic avenues for managing fungal infections.


Assuntos
Candida glabrata , Candidíase , Animais , Camundongos , Candida glabrata/fisiologia , Glucocorticoides/farmacologia , Glucocorticoides/metabolismo , Sirolimo/farmacologia , Camundongos Endogâmicos BALB C , Autofagia , Macrófagos , Serina-Treonina Quinases TOR/metabolismo , Mamíferos
4.
Pathol Oncol Res ; 30: 1611643, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38515456

RESUMO

The increasing knowledge of molecular alterations in malignancies, including mutations and regulatory failures in the mTOR (mechanistic target of rapamycin) signaling pathway, highlights the importance of mTOR hyperactivity as a validated target in common and rare malignancies. This review summarises recent findings on the characterization and prognostic role of mTOR kinase complexes (mTORC1 and mTORC2) activity regarding differences in their function, structure, regulatory mechanisms, and inhibitor sensitivity. We have recently identified new tumor types with RICTOR (rapamycin-insensitive companion of mTOR) amplification and associated mTORC2 hyperactivity as useful potential targets for developing targeted therapies in lung cancer and other newly described malignancies. The activity of mTOR complexes is recommended to be assessed and considered in cancers before mTOR inhibitor therapy, as current first-generation mTOR inhibitors (rapamycin and analogs) can be ineffective in the presence of mTORC2 hyperactivity. We have introduced and proposed a marker panel to determine tissue characteristics of mTOR activity in biopsy specimens, patient materials, and cell lines. Ongoing phase trials of new inhibitors and combination therapies are promising in advanced-stage patients selected by genetic alterations, molecular markers, and/or protein expression changes in the mTOR signaling pathway. Hopefully, the summarized results, our findings, and the suggested characterization of mTOR activity will support therapeutic decisions.


Assuntos
Neoplasias Pulmonares , Serina-Treonina Quinases TOR , Humanos , Proteína Companheira de mTOR Insensível à Rapamicina/genética , Proteína Companheira de mTOR Insensível à Rapamicina/metabolismo , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Sirolimo/farmacologia , Fatores de Transcrição/metabolismo
5.
J Assoc Res Otolaryngol ; 25(2): 149-165, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38472516

RESUMO

PURPOSE: To investigate the impact of rapamycin on the differentiation of hair cells. METHODS: Murine cochlear organoids were derived from cochlear progenitor cells. Different concentrations of rapamycin were added into the culture medium at different proliferation and differentiation stages. RESULTS: Rapamycin exhibited a concentration-dependent reduction in the proliferation of these inner ear organoids. Nevertheless, organoids subjected to a 10-nM dose of rapamycin demonstrated a markedly increased proportion of hair cells. Furthermore, rapamycin significantly upregulated the expression of markers associated with both hair cells and supporting cells, including ATOH1, MYO7A, and SOX2. Mechanistic studies revealed that rapamycin preferentially suppressed cells without Sox2 expression during the initial proliferation stage, thereby augmenting and refining the population of SOX2+ progenitors. These enriched progenitors were predisposed to differentiate into hair cells during the later stages of organoid development. Conversely, the use of the mTOR activator MHY 1485 demonstrated opposing effects. CONCLUSION: Our findings underscore a practical strategy for enhancing the generation of inner ear organoids with a low dose of rapamycin, achieved by enriching SOX2+ progenitors in an in vitro setting.


Assuntos
Orelha Interna , Sirolimo , Animais , Camundongos , Animais Recém-Nascidos , Sirolimo/farmacologia , Diferenciação Celular , Organoides
6.
J Exp Zool A Ecol Integr Physiol ; 341(4): 470-482, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38433718

RESUMO

The protective action of melatonin (MLT) against the harmful effects of cadmium (Cd) on testicular activity in rats has been documented previously; however, the involved molecular mechanisms have yet to be elucidated. Herein, we investigate the involvement of the mammalian target of rapamycin (mTOR) on the ability of MLT to counteract the damage induced by Cd on the rat testicular activity. Our study confirmed that Cd has harmful effects on the testes of rats and the protective action exerted by MLT. We reported, for the first time, that the addition of rapamycin (Rapa), a specific mTOR inhibitor, to animals co-treated with Cd and MLT completely abolished the beneficial effects exerted by MLT, indicating that the mTOR pathway partially modulates its helpful effects on Cd testicular toxicity. Interestingly, Rapa-alone treatment, provoking mTOR inhibition, produced altered morphological parameters, increased autophagy of germ and somatic cells, and reduced serum testosterone concentration. In addition, mTOR inhibition also reduced protein levels of markers of steroidogenesis (3ß-Hydroxysteroid dehydrogenase) and blood-testis barrier integrity (occludin and connexin 43). Finally, Rapa altered sperm parameters as well as the ability of mature spermatozoa to perform a proper acrosome reaction. Although further investigation is needed to better clarify the molecular pathway involved in MLT action, we confirm that MLT alleviating Cd effects can be used as a supplement to enhance testicular function and improve male gamete quality.


Assuntos
Melatonina , Ratos , Masculino , Animais , Melatonina/farmacologia , Cádmio/toxicidade , Sirolimo/farmacologia , Sêmen/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Mamíferos/metabolismo
7.
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
8.
J Alzheimers Dis ; 98(1): 301-318, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38427475

RESUMO

Background: Alzheimer's disease (AD) is characterized by disrupted proteostasis and macroautophagy (hereafter "autophagy"). The pharmacological agent suramin has known autophagy modulation properties with potential efficacy in mitigating AD neuronal pathology. Objective: In the present work, we investigate the impact of forebrain neuron exposure to suramin on the Akt/mTOR signaling pathway, a major regulator of autophagy, in comparison with rapamycin and chloroquine. We further investigate the effect of suramin on several AD-related biomarkers in sporadic AD (sAD)-derived forebrain neurons. Methods: Neurons differentiated from ReNcell neural progenitors were used to assess the impact of suramin on the Akt/mTOR signaling pathway relative to the autophagy inducer rapamycin and autophagy inhibitor chloroquine. Mature forebrain neurons were differentiated from induced pluripotent stem cells (iPSCs) sourced from a late-onset sAD patient and treated with 100µM suramin for 72 h, followed by assessments for amyloid-ß, phosphorylated tau, oxidative/nitrosative stress, and synaptic puncta density. Results: Suramin treatment of sAD-derived neurons partially ameliorated the increased p-Tau(S199)/Tau ratio, and fully remediated the increased glutathione to oxidized nitric oxide ratio, observed in untreated sAD-derived neurons relative to healthy controls. These positive results may be due in part to the distinct increases in Akt/mTOR pathway mediator p-p70S6K noted with suramin treatment of both ReNcell-derived and iPSC-derived neurons. Longer term neuronal markers, such as synaptic puncta density, were unaffected by suramin treatment. Conclusions: These findings provide initial evidence supporting the potential of suramin to reduce the degree of dysregulation in sAD-derived forebrain neurons in part via the modulation of autophagy.


Assuntos
Doença de Alzheimer , Células-Tronco Pluripotentes Induzidas , Humanos , Doença de Alzheimer/patologia , Suramina/farmacologia , Suramina/metabolismo , Proteínas tau/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Peptídeos beta-Amiloides/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Prosencéfalo/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Neurônios/metabolismo , Sirolimo/farmacologia , Cloroquina/metabolismo , Cloroquina/farmacologia
9.
BMC Neurosci ; 25(1): 16, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38468222

RESUMO

BACKGROUND: Myelin oligodendrocyte glycoprotein-associated disorders (MOGAD) is an autoimmune central nervous system disease. Antigen-specific immune tolerance using nanoparticles such as Polylactic-co-glycolic acid (PLGA) have recently been used as a new therapeutic tolerization approach for CNS autoimmune diseases. We examined whether MOG1-125 conjugated with PLGA could induce MOG-specific immune tolerance in an experimental autoimmune encephalitis (EAE) mouse model. EAE was induced in sixty C57BL/6 J wild-type mice using MOG1-125 peptide with complete Freund's Adjuvant. The mice were divided into 12 groups (n = 5 each) to test the ability of MOG1-125 conjugated PLGA intervention to mitigate the severity or improve the outcomes from EAE with and without rapamycin compared to antigen alone or PLGA alone. EAE score and serum MOG-IgG titers were compared among the interventions.Kindly check and confirm the processed Affiliation “4” is appropriate.I confirmed the Aff 4.Affiliation: Corresponding author information have been changed to present affiliation. Kindly check and confirm.I checked and confirmed the Corresponding author's information. RESULTS: Mice with EAE that were injected intraperitoneally with MOG1-125 conjugated PLGA + rapamycin complex showed dose-dependent mitigation of EAE score. Intraperitoneal and intravenous administration resulted in similar clinical outcomes, whereas 80% of mice treated with subcutaneous injection had a recurrence of clinical score worsening after approximately 1 week. Although there was no significant difference in EAE scores between unconjugated-PLGA and MOG-conjugated PLGA, serum MOG-IgG tended to decrease in the MOG-conjugated PLGA group compared to controls. CONCLUSION: Intraperitoneal administration of PLGA resulted in dose-dependent and longer-lasting immune tolerance than subcutaneous administration. The induction of immune tolerance using PLGA may represent a future therapeutic option for patients with MOGAD.


Assuntos
Encefalite , Encefalomielite Autoimune Experimental , Doença de Hashimoto , Poliésteres , Humanos , Camundongos , Animais , Glicoproteína Mielina-Oligodendrócito/efeitos adversos , Encefalomielite Autoimune Experimental/induzido quimicamente , Encefalomielite Autoimune Experimental/tratamento farmacológico , Camundongos Endogâmicos C57BL , Glicóis/efeitos adversos , Sirolimo/farmacologia , Imunoglobulina G/efeitos adversos
10.
Int J Nanomedicine ; 19: 2265-2284, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38476273

RESUMO

Introduction: Glaucoma is a prevalent cause of irreversible vision impairment, characterized by progressive retinal ganglion cells (RGCs) loss, with no currently available effective treatment. Rapamycin (RAPA), an autophagy inducer, has been reported to treat glaucoma in rodent models by promoting RGC survival, but its limited water solubility, systemic toxicity, and pre-treatment requirements hinder its potential clinical applications. Methods: Chitosan (CS)-RAPA carbon dot (CRCD) was synthesized via hydrothermal carbonization of CS and RAPA and characterized by transmission electron microscopy, Fourier transform infrared spectra, and proton nuclear magnetic resonance. In vitro assays on human umbilical cord vein endothelial and rat retinal cell line examined its biocompatibility and anti-oxidative capabilities, while lipopolysaccharide-stimulated murine microglia (BV2) assays measured its effects on microglial polarization. In vivo, using a mouse retinal ischemia/reperfusion (I/R) model by acute intraocular pressure elevation, the effects of CRCD on visual function, RGC apoptosis, oxidative stress, and M2 microglial polarization were examined. Results: CRCD exhibited good water solubility and anti-oxidative capabilities, in the form of free radical scavenging. In vitro, CRCD was bio-compatible and lowered oxidative stress, which was also found in vivo in the retinal I/R model. Additionally, both in vitro with lipopolysaccharide-stimulated BV2 cells and in vivo with the I/R model, CRCD was able to promote M2 microglial polarization by activating autophagy, which, in turn, down-regulated pro-inflammatory cytokines, such as IL-1ß and TNF-α, as well as up-regulated anti-inflammatory cytokines, such as IL-4 and TGF-ß. All these anti-oxidative and anti-inflammatory effects ultimately aided in preserving RGCs, and subsequently, improved visual function. Discussion: CRCD could serve as a potential novel treatment strategy for glaucoma, via incorporating RAPA into CDs, in turn not only mitigating its toxic side effects but also enhancing its therapeutic efficacy.


Assuntos
Quitosana , Glaucoma , Traumatismo por Reperfusão , Ratos , Animais , Camundongos , Humanos , Microglia/patologia , Quitosana/farmacologia , Sirolimo/farmacologia , Carbono/farmacologia , Lipopolissacarídeos/farmacologia , Glaucoma/tratamento farmacológico , Anti-Inflamatórios/farmacologia , Modelos Animais de Doenças , Autofagia , Citocinas/metabolismo , Água , Traumatismo por Reperfusão/tratamento farmacológico
11.
Cells ; 13(5)2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38474373

RESUMO

The mechanistic target of rapamycin (mTOR) is a serine/threonine kinase that functions via its discrete binding partners to form two multiprotein complexes, mTOR complex 1 and 2 (mTORC1 and mTORC2). Rapamycin-sensitive mTORC1, which regulates protein synthesis and cell growth, is tightly controlled by PI3K/Akt and is nutrient-/growth factor-sensitive. In the brain, mTORC1 is also sensitive to neurotransmitter signaling. mTORC2, which is modulated by growth factor signaling, is associated with ribosomes and is insensitive to rapamycin. mTOR regulates stem cell and cancer stem cell characteristics. Aberrant Akt/mTOR activation is involved in multistep tumorigenesis in a variety of cancers, thereby suggesting that the inhibition of mTOR may have therapeutic potential. Rapamycin and its analogues, known as rapalogues, suppress mTOR activity through an allosteric mechanism that only suppresses mTORC1, albeit incompletely. ATP-catalytic binding site inhibitors are designed to inhibit both complexes. This review describes the regulation of mTOR and the targeting of its complexes in the treatment of cancers, such as glioblastoma, and their stem cells.


Assuntos
Glioblastoma , Células-Tronco Neoplásicas , Sirolimo , Humanos , Glioblastoma/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/uso terapêutico , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/metabolismo , Células-Tronco Neoplásicas/metabolismo
12.
J Exp Clin Cancer Res ; 43(1): 46, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38342894

RESUMO

BACKGROUND: Nasopharyngeal carcinoma (NPC) poses a significant health burden in specific regions of Asia, and some of NPC patients have bone metastases at the time of initial diagnosis. Bone metastasis can cause pathologic fractures and pain, reducing patients' quality of life, and is associated with worse survival. This study aims to unravel the complex role of insulin-like growth factor 1 receptor (IGF-1R) in NPC bone metastasis, offering insights into potential therapeutic targets. METHODS: We assessed IGF-1R expression in NPC cells and explored its correlation with bone metastasis. Experiments investigated the impact of osteoclast-secreted IGF-1 on the IGF-1R/AKT/S6 pathway in promoting NPC cell proliferation within the bone marrow. Additionally, the reciprocal influence of tumor-secreted Granulocyte-macrophage colony-stimulating factor (GM-CSF) on osteoclast differentiation and bone resorption was examined. The effects of IGF-1 neutralizing antibody, IGF-1R specific inhibitor (NVP-AEW541) and mTORC inhibitor (rapamycin) on nasopharyngeal carcinoma bone metastasis were also explored in animal experiments. RESULTS: Elevated IGF-1R expression in NPC cells correlated with an increased tendency for bone metastasis. IGF-1, secreted by osteoclasts, activated the IGF-1R/AKT/S6 pathway, promoting NPC cell proliferation in the bone marrow. Tumor-secreted GM-CSF further stimulated osteoclast differentiation, exacerbating bone resorption. The IGF-1 neutralizing antibody, NVP-AEW541 and rapamycin were respectively effective in slowing down the rate of bone metastasis and reducing bone destruction. CONCLUSION: The intricate interplay among IGF-1R, IGF-1, and GM-CSF highlights potential therapeutic targets for precise control of NPC bone metastasis, providing valuable insights for developing targeted interventions.


Assuntos
Neoplasias Ósseas , Reabsorção Óssea , Neoplasias Nasofaríngeas , Animais , Humanos , Carcinoma Nasofaríngeo/patologia , Fator de Crescimento Insulin-Like I/metabolismo , Fator de Crescimento Insulin-Like I/farmacologia , Fator de Crescimento Insulin-Like I/uso terapêutico , Osteoclastos/metabolismo , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/uso terapêutico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Qualidade de Vida , Linhagem Celular Tumoral , Neoplasias Nasofaríngeas/patologia , Sirolimo/farmacologia , Anticorpos Neutralizantes
13.
Mol Brain ; 17(1): 9, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38360671

RESUMO

One of the main hallmarks of Parkinson's disease (PD) is abnormal alpha-synuclein (α-syn) aggregation which forms the main component of intracellular Lewy body inclusions. This short report used preformed α-syn fibrils, as well as an A53T mutant α-syn adenovirus to mimic conditions of pathological protein aggregation in dopaminergic human derived SH-SY5Y neural cells. Since there is evidence that the mTOR pathway and glutamatergic signaling each influence protein aggregation, we also assessed the impact of the mTOR inhibitor, rapamycin and the mGluR5 allosteric modulator, CTEP. We found that both rapamycin and CTEP induced a significant reduction of α-syn fibrils in SH-SY5Y cells and this effect was associated with a reduction in mTOR signaling and enhancement in autophagic pathway factors. These data support the possibility that CTEP (or rapamycin) might be a useful pharmacological approach to target abnormal α-syn accumulation by promoting intracellular degradation or enhanced clearance.


Assuntos
Doença de Parkinson , Receptor de Glutamato Metabotrópico 5 , Serina-Treonina Quinases TOR , alfa-Sinucleína , Humanos , alfa-Sinucleína/metabolismo , Doença de Parkinson/metabolismo , Sirolimo/farmacologia , Receptor de Glutamato Metabotrópico 5/metabolismo
14.
Int J Immunopathol Pharmacol ; 38: 3946320241234741, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38379215

RESUMO

OBJECTIVE: We aimed to explore the effect and potential mechanism of Sestrin 2 (SESN2) in human lens epithelial cells (HLECs). METHODS: To mimic the oxidative stress environment, SAR01/04 cells were treated with 200 µM hydrogen peroxide (H2O2) for 24 h. Cell viability and apoptosis were checked by cell counting kit-8 and flow cytometry. Western blot was taken to check the protein changes of SESN2, B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X (Bax), mechanistic target of rapamycin (mTOR), phosphorylated (p)-mTOR, ribosomal protein S6 kinase B1 (p70S6K), p-p70S6K, and nuclear factor erythroid 2-related factor 2 (Nrf2). Superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), and reactive oxygen species (ROS) were detected via the corresponding reagent kit. The levels of interleukin (IL)-1ß, IL-18, and tumor necrosis factor (TNF)-α were measured using enzyme-linked immunosorbent assay. RESULTS: SESN2 was down-regulated in cataract lens tissue and up-regulated in SAR01/04 cells treated with H2O2. Under treatment of H2O2, up-regulation of SESN2 improved cell viability, enhanced the activity of SOD and CAT, inhibited cell apoptosis, and reduced the levels of MDA, ROS, IL-1ß, IL-18, and TNF-α, while down-regulation of SESN2 caused the contrary effects. Further bioinformatics analysis suggested that SESN2 regulated the mTOR signaling pathway. Treatment of H2O2 inhibited p-mTOR and p-p70S6K protein expression, while overexpression of SESN2 increased p-mTOR and p-p70S6K protein expression in the H2O2 group and down-regulation of SESN2 further decreased p-mTOR and p-p70S6K protein expression in the H2O2 group. Additionally, H2O2 increased Nrf2 protein expression, and overexpression of SESN2 further increased Nrf2 protein expression in the H2O2 group. Importantly, rapamycin (an inhibitor of mTOR signaling pathway) and knockdown of Nrf2 reversed the promotive effects of SESN2 on cell viability and the inhibitive effects of SESN2 on cell apoptosis, oxidative stress, and inflammatory reaction. CONCLUSION: SESN2 protected HLECs damage induced by H2O2, which was related to the activation of mTOR/Nrf2 pathway.


Assuntos
Peróxido de Hidrogênio , Fator 2 Relacionado a NF-E2 , Humanos , Espécies Reativas de Oxigênio/metabolismo , Peróxido de Hidrogênio/farmacologia , Interleucina-18/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Sestrinas/metabolismo , Estresse Oxidativo , Apoptose , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Células Epiteliais/metabolismo , Superóxido Dismutase , Sirolimo/farmacologia , Sobrevivência Celular
15.
Psychopharmacology (Berl) ; 241(3): 601-612, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38311691

RESUMO

RATIONALE: The mammalian target of rapamycin (mTOR) kinase is known to mediate consolidation and reconsolidation of aversive memories. Most studies in this area use a forward conditioning paradigm in which the conditioned stimulus (CS) precedes the unconditioned stimulus (US). Little is known, however, about the neurobiological underpinnings of backwards (BW) conditioning paradigms, particularly in female mice. In BW conditioning, the CS does not become directly associated with the US; it instead evokes conditioned fear by reactivating a memory of the conditioning context and indirectly retrieving a memory of the aversive US. OBJECTIVES: We sought to examine BW conditioned fear memory processes in female mice. First, we examined whether freezing to a BW CS is mediated by fear to the conditioning context. Second, we tested whether blocking consolidation of a BW CS attenuated memory of the CS and conditioning context. Finally, we tested whether blocking reconsolidation of a BW CS attenuated memory of the conditioning context. RESULTS: We show that conditioned freezing to a BW CS is mediated by fear to the conditioning context. Furthermore, rapamycin-an mTOR inhibitor, when given immediately following BW conditioning, impairs consolidation of both cued and contextual fear memory. Similarly, rapamycin given following retrieval of a BW CS blocks context recall. Rapamycin is acting on reconsolidation as CS retrieval is necessary to see the effects of rapamycin on context memory recall. CONCLUSIONS: Our study provides novel evidence that indirect retrieval cues are sensitive to rapamycin in female mice. The capacity to indirectly reactivate memories and render them susceptible to disruption is critical in the translation of reconsolidation-based approaches to the clinic.


Assuntos
Afeto , Sirolimo , Feminino , Animais , Camundongos , Sirolimo/farmacologia , Condicionamento Clássico , Condicionamento Operante , Serina-Treonina Quinases TOR , Mamíferos
16.
Food Chem Toxicol ; 185: 114508, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38336017

RESUMO

Manganese (Mn) is a well-known environmental pollutant and occupational toxicant that causes neurotoxicity, which present as neurodegenerative-like symptoms. However, the mechanism of Mn-induced neuronal injury remains unclear. In this research, we explored the mechanism of Mn-induced neurotoxicity, focusing on the mTOR signaling pathway. A plasmid expressing a short hairpin RNA (shRNA) targeting mTOR (shRNA-mTOR) was transfected into N27 cells in vitro, and rapamycin was used as an mTOR inhibitor in vivo to block the mTOR signaling pathway. Cells were treated with different concentrations of manganese (II) chloride (MnCl2). We found that Mn induced cell injury and apoptosis and markedly upregulated the expression of mTOR pathway-related proteins. The phosphorylation of 4E-BP1, S6K1, Akt and SGK1 was markedly decreased after blocking mTOR, and cell apoptosis was also reduced. Furthermore, the mTOR-specific inhibitor rapamycin restored learning and memory abilities in vivo. This research highlights that inhibiting mTOR might be useful for preventing Mn-induced neurodegenerative-like disorders.


Assuntos
Manganês , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Apoptose , Fosforilação , Sirolimo/farmacologia , RNA Interferente Pequeno , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo
17.
Int J Neuropsychopharmacol ; 27(2)2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38365306

RESUMO

Economic development and increased stress have considerably increased the prevalence of psychiatric disorders in recent years, which rank as some of the most prevalent diseases globally. Several factors, including chronic social stress, genetic inheritance, and autogenous diseases, lead to the development and progression of psychiatric disorders. Clinical treatments for psychiatric disorders include psychotherapy, chemotherapy, and electric shock therapy. Although various achievements have been made researching psychiatric disorders, the pathogenesis of these diseases has not been fully understood yet, and serious adverse effects and resistance to antipsychotics are major obstacles to treating patients with psychiatric disorders. Recent studies have shown that the mammalian target of rapamycin (mTOR) is a central signaling hub that functions in nerve growth, synapse formation, and plasticity. The PI3K-AKT/mTOR pathway is a critical target for mediating the rapid antidepressant effects of these pharmacological agents in clinical and preclinical research. Abnormal PI3K-AKT/mTOR signaling is closely associated with the pathogenesis of several neurodevelopmental disorders. In this review, we focused on the role of mTOR signaling and the related aberrant neurogenesis in psychiatric disorders. Elucidating the neurobiology of the PI3K-AKT/mTOR signaling pathway in psychiatric disorders and its actions in response to antidepressants will help us better understand brain development and quickly identify new therapeutic targets for the treatment of these mental illnesses.


Assuntos
Transtornos Mentais , Proteínas Proto-Oncogênicas c-akt , Humanos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Sirolimo/farmacologia , Antidepressivos/farmacologia , Transtornos Mentais/tratamento farmacológico
18.
Cells ; 13(3)2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38334632

RESUMO

Melanoma frequently harbors genetic alterations in key molecules leading to the aberrant activation of PI3K and its downstream pathways. Although the role of PI3K/AKT/mTOR in melanoma progression and drug resistance is well documented, targeting the PI3K/AKT/mTOR pathway showed less efficiency in clinical trials than might have been expected, since the suppression of the PI3K/mTOR signaling pathway-induced feedback loops is mostly associated with the activation of compensatory pathways such as MAPK/MEK/ERK. Consequently, the development of intrinsic and acquired resistance can occur. As a solid tumor, melanoma is notorious for its heterogeneity. This can be expressed in the form of genetically divergent subpopulations including a small fraction of cancer stem-like cells (CSCs) and non-cancer stem cells (non-CSCs) that make the most of the tumor mass. Like other CSCs, melanoma stem-like cells (MSCs) are characterized by their unique cell surface proteins/stemness markers and aberrant signaling pathways. In addition to its function as a robust marker for stemness properties, CD133 is crucial for the maintenance of stemness properties and drug resistance. Herein, the role of CD133-dependent activation of PI3K/mTOR in the regulation of melanoma progression, drug resistance, and recurrence is reviewed.


Assuntos
Melanoma , Sirolimo , Humanos , Sirolimo/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Melanoma/patologia , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Resistencia a Medicamentos Antineoplásicos
19.
Lancet Healthy Longev ; 5(2): e152-e162, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38310895

RESUMO

Rapamycin and its derivatives (rapalogs) are inhibitors of mTOR, a major regulator of the ageing process. We aimed to summarise the effects of rapamycin and its derivatives on the severity of ageing-related physiological changes and disease in adults. A search across five databases yielded 18 400 unique articles, resulting in 19 included studies. Rapamycin and its derivatives improved physiological parameters associated with ageing in the immune, cardiovascular, and integumentary systems of healthy individuals or individuals with ageing-related diseases. Overall, no significant effects on the endocrine, muscular, or neurological systems were found. The effects of rapamycin or its derivatives on the respiratory, digestive, renal, and reproductive systems were not assessed. No serious adverse events attributed to rapamycin and its derivatives were reported in healthy individuals; however, there were increased numbers of infections and increases in total cholesterol, LDL cholesterol, and triglycerides in individuals with ageing-related diseases. Future studies should assess the remaining unexamined systems and test the effects of long-term exposure to rapamycin and its derivatives.


Assuntos
Envelhecimento , Sirolimo , Humanos , Sirolimo/farmacologia
20.
J Transl Med ; 22(1): 166, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38365767

RESUMO

BACKGROUND: Coronary artery bypass graft (CABG) is generally used to treat complex coronary artery disease. Treatment success is affected by neointimal hyperplasia (NIH) of graft and anastomotic sites. Although sirolimus and rosuvastatin individually inhibit NIH progression, the efficacy of combination treatment remains unknown. METHODS: We identified cross-targets associated with CABG, sirolimus, and rosuvastatin by using databases including DisGeNET and GeneCards. GO and KEGG pathway enrichment analyses were conducted using R studio, and target proteins were mapped in PPI networks using Metascape and Cytoscape. For in vivo validation, we established a balloon-injured rabbit model by inducing NIH and applied a localized perivascular drug delivery device containing sirolimus and rosuvastatin. The outcomes were evaluated at 1, 2, and 4 weeks post-surgery. RESULTS: We identified 115 shared targets between sirolimus and CABG among databases, 23 between rosuvastatin and CABG, and 96 among all three. TNF, AKT1, and MMP9 were identified as shared targets. Network pharmacology predicted the stages of NIH progression and the corresponding signaling pathways linked to sirolimus (acute stage, IL6/STAT3 signaling) and rosuvastatin (chronic stage, Akt/MMP9 signaling). In vivo experiments demonstrated that the combination of sirolimus and rosuvastatin significantly suppressed NIH progression. This combination treatment also markedly decreased the expression of inflammation and Akt signaling pathway-related proteins, which was consistent with the predictions from network pharmacology analysis. CONCLUSIONS: Sirolimus and rosuvastatin inhibited pro-inflammatory cytokine production during the acute stage and regulated Akt/mTOR/NF-κB/STAT3 signaling in the chronic stage of NIH progression. These potential synergistic mechanisms may optimize treatment strategies to improve long-term patency after CABG.


Assuntos
Medicamentos de Ervas Chinesas , Sirolimo , Animais , Coelhos , Sirolimo/farmacologia , Sirolimo/uso terapêutico , Rosuvastatina Cálcica/farmacologia , Rosuvastatina Cálcica/uso terapêutico , Hiperplasia/tratamento farmacológico , Metaloproteinase 9 da Matriz , Farmacologia em Rede , Proteínas Proto-Oncogênicas c-akt , Neointima , Ponte de Artéria Coronária/efeitos adversos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...