RESUMO
Rapamycin, an inhibitor of mechanistic Target Of Rapamycin Complex 1 (mTORC1), extends lifespan and shows strong potential for the treatment of age-related diseases. However, rapamycin exerts metabolic and immunological side effects mediated by off-target inhibition of a second mTOR-containing complex, mTOR complex 2. Here, we report the identification of DL001, a FKBP12-dependent rapamycin analog 40x more selective for mTORC1 than rapamycin. DL001 inhibits mTORC1 in cell culture lines and in vivo in C57BL/6J mice, in which DL001 inhibits mTORC1 signaling without impairing glucose homeostasis and with substantially reduced or no side effects on lipid metabolism and the immune system. In cells, DL001 efficiently represses elevated mTORC1 activity and restores normal gene expression to cells lacking a functional tuberous sclerosis complex. Our results demonstrate that highly selective pharmacological inhibition of mTORC1 can be achieved in vivo, and that selective inhibition of mTORC1 significantly reduces the side effects associated with conventional rapalogs.
Assuntos
Alvo Mecanístico do Complexo 1 de Rapamicina/antagonistas & inibidores , Sirolimo/análogos & derivados , Sirolimo/farmacologia , Animais , Linhagem Celular , Descoberta de Drogas , Expressão Gênica/efeitos dos fármacos , Humanos , Sistema Imunitário/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Proteômica , Transdução de Sinais/efeitos dos fármacos , Sirolimo/química , Serina-Treonina Quinases TOR , Esclerose TuberosaRESUMO
Physiological and premature aging are frequently associated with an accumulation of prelamin A, a precursor of lamin A, in the nuclear envelope of various cell types. Here, we aimed to underpin the hitherto unknown mechanisms by which prelamin A alters myonuclear organization and muscle fiber function. By experimentally studying membrane-permeabilized myofibers from various transgenic mouse lines, our results indicate that, in the presence of prelamin A, the abundance of nuclei and myosin content is markedly reduced within muscle fibers. This leads to a concept by which the remaining myonuclei are very distant from each other and are pushed to function beyond their maximum cytoplasmic capacity, ultimately inducing muscle fiber weakness.
Assuntos
Senilidade Prematura/fisiopatologia , Núcleo Celular/metabolismo , Lamina Tipo A/metabolismo , Fibras Musculares Esqueléticas/fisiologia , Força Muscular , Senilidade Prematura/genética , Animais , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular/fisiologia , Células Cultivadas , Modelos Animais de Doenças , Humanos , Lamina Tipo A/genética , Camundongos , Camundongos Knockout , Fibras Musculares Esqueléticas/citologia , Miosinas/metabolismo , Cultura Primária de CélulasRESUMO
Cinnamomum cassia exhibits antioxidative, apoptotic, and cytostatic properties. These activities have been attributed to the modulation of several biological processes and are beneficial for possible pharmaceutical applications. However, the potential of C. cassia in retarding lung adenocarcinoma cells metastasis remains ambiguous. We determined whether C. cassia extract (CCE) reduces metastasis of human lung adenocarcinoma cells. The results showed that CCE treatment (up to 60 µg/mL) for 24 h exhibited no cytotoxicity on the A549 and H1299 cell lines but inhibited the motility, invasiveness, and migration of these cells by repressing matrix metalloproteinase (MMP)-2 and urokinase-type plasminogen activator (u-PA). CCE also impaired cell adhesion to collagen. CCE significantly reduced p-focal adhesion kinase (FAK) Tyr397, p-FAK Tyr925, p-extracellular signal-regulated kinases (ERK)1/2, and Ras homolog gene family (Rho)A expression. CCE showed anti-metastatic activity of A549 and H1299 cells by repressing u-PA/MMP-2 via FAK to ERK1/2 pathways. These findings may facilitate future clinical trials of lung adenocarcinoma chemotherapy to confirm the promising results.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Cinnamomum aromaticum/química , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Extratos Vegetais/farmacologia , Células A549 , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Colágeno , Quinase 1 de Adesão Focal/metabolismo , Gelatina , Humanos , Neoplasias Pulmonares/patologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Metaloproteinase 2 da Matriz , Fosforilação/efeitos dos fármacos , Ativador de Plasminogênio Tipo Uroquinase/metabolismo , Proteína rhoA de Ligação ao GTP/metabolismoRESUMO
The role of oxidative stress in the aging process has been highly debated for decades and remains equivocal. A new study published in Cell Research reports a novel role for the aging-associated SIRT6 deacetylase in the control of oxidative homeostasis in human mesenchymal stem cells.
Assuntos
Estresse Oxidativo , Sirtuínas/metabolismo , Envelhecimento , Humanos , Células-Tronco Mesenquimais/metabolismoRESUMO
The mechanism by which the drug rapamycin inhibits the mechanistic target of rapamycin (mTOR) is of intense interest because of its likely relevance in cancer biology, aging, and other age-related diseases. While rapamycin acutely and directly inhibits mTORC1, only chronic administration of rapamycin can inhibit mTORC2 in some, but not all, cell lines or tissues. The mechanism leading to cell specificity of mTORC2 inhibition by rapamycin is not understood and is especially important because many of the negative metabolic side effects of rapamycin, reported in mouse studies and human clinical trials, have been attributed recently to mTORC2 inhibition. Here, we identify the expression level of different FK506-binding proteins (FKBPs), primarily FKBP12 and FKBP51, as the key determinants for rapamycin-mediated inhibition of mTORC2. In support, enforced reduction of FKBP12 completely converts a cell line that is sensitive to mTORC2 inhibition to an insensitive cell line, and increased expression can enhance mTORC2 inhibition. Further reduction of FKBP12 in cell lines with already low FKBP12 levels completely blocks mTORC1 inhibition by rapamycin, indicating that relative FKBP12 levels are critical for both mTORC1 and mTORC2 inhibition, but at different levels. In contrast, reduction of FKBP51 renders cells more sensitive to mTORC2 inhibition. Our findings reveal that the expression of FKBP12 and FKBP51 is the rate limiting factor that determines the responsiveness of a cell line or tissue to rapamycin. These findings have implications for treating specific diseases, including neurodegeneration and cancer, as well as targeting aging in general.
Assuntos
Complexos Multiproteicos/antagonistas & inibidores , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Proteínas de Ligação a Tacrolimo/biossíntese , Fatores Etários , Animais , Antibióticos Antineoplásicos/farmacologia , Células HEK293 , Células HeLa , Humanos , Alvo Mecanístico do Complexo 2 de Rapamicina , Camundongos , Complexos Multiproteicos/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Proteínas de Ligação a Tacrolimo/metabolismoRESUMO
Aging is a complex, multifactorial process that is likely influenced by the activities of a range of biological pathways. Genetic approaches to identify genes modulating longevity have been highly successful and recent efforts have extended these studies to mammalian aging. A variety of genetic models have been reported to have enhanced lifespan and, similarly, many genetic interventions lead to progeroid phenotypes. Here, we detail and evaluate both sets of models, focusing on the insights they provide about the molecular processes modulating aging and the extent to which mutations conferring progeroid pathologies really phenocopy accelerated aging.