RESUMO
Reprograming of proline metabolism is critical for tumor growth. Here we show that PINCH-1 is highly expressed in lung adenocarcinoma and promotes proline synthesis through regulation of mitochondrial dynamics. Knockout (KO) of PINCH-1 increases dynamin-related protein 1 (DRP1) expression and mitochondrial fragmentation, which suppresses kindlin-2 mitochondrial translocation and interaction with pyrroline-5-carboxylate reductase 1 (PYCR1), resulting in inhibition of proline synthesis and cell proliferation. Depletion of DRP1 reverses PINCH-1 deficiency-induced defects on mitochondrial dynamics, proline synthesis and cell proliferation. Furthermore, overexpression of PYCR1 in PINCH-1 KO cells restores proline synthesis and cell proliferation, and suppresses DRP1 expression and mitochondrial fragmentation. Finally, ablation of PINCH-1 from lung adenocarcinoma in mouse increases DRP1 expression and inhibits PYCR1 expression, proline synthesis, fibrosis and tumor growth. Our results identify a signaling axis consisting of PINCH-1, DRP1 and PYCR1 that regulates mitochondrial dynamics and proline synthesis, and suggest an attractive strategy for alleviation of tumor growth.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adenocarcinoma de Pulmão/patologia , Proteínas com Domínio LIM/metabolismo , Neoplasias Pulmonares/patologia , Proteínas de Membrana/metabolismo , Células A549 , Proteínas Adaptadoras de Transdução de Sinal/genética , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Proliferação de Células/genética , Proteínas do Citoesqueleto/metabolismo , Modelos Animais de Doenças , Dinaminas/metabolismo , Feminino , Técnicas de Inativação de Genes , Humanos , Proteínas com Domínio LIM/genética , Pulmão/citologia , Pulmão/patologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/mortalidade , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Transgênicos , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Dinâmica Mitocondrial , Proteínas Musculares/metabolismo , Proteínas de Neoplasias/metabolismo , Prolina/biossíntese , Proteínas Proto-Oncogênicas p21(ras)/genética , Pirrolina Carboxilato Redutases/metabolismo , Análise de Sobrevida , delta-1-Pirrolina-5-Carboxilato RedutaseRESUMO
Cell metabolism is strongly influenced by mechano-environment. We show here that a fraction of kindlin-2 localizes to mitochondria and interacts with pyrroline-5-carboxylate reductase 1 (PYCR1), a key enzyme for proline synthesis. Extracellular matrix (ECM) stiffening promotes kindlin-2 translocation into mitochondria and its interaction with PYCR1, resulting in elevation of PYCR1 level and consequent increase of proline synthesis and cell proliferation. Depletion of kindlin-2 reduces PYCR1 level, increases reactive oxygen species (ROS) production and apoptosis, and abolishes ECM stiffening-induced increase of proline synthesis and cell proliferation. In vivo, both kindlin-2 and PYCR1 levels are markedly increased in lung adenocarcinoma. Ablation of kindlin-2 in lung adenocarcinoma substantially reduces PYCR1 and proline levels, and diminishes fibrosis in vivo, resulting in marked inhibition of tumor growth and reduction of mortality rate. Our findings reveal a mechanoresponsive kindlin-2-PYCR1 complex that links mechano-environment to proline metabolism and signaling, and suggest a strategy to inhibit tumor growth.
Assuntos
Adenocarcinoma de Pulmão/metabolismo , Proteínas do Citoesqueleto/metabolismo , Neoplasias Pulmonares/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Musculares/metabolismo , Proteínas de Neoplasias/metabolismo , Prolina/biossíntese , Células A549 , Adenocarcinoma de Pulmão/patologia , Animais , Proliferação de Células/fisiologia , Sobrevivência Celular/fisiologia , Proteínas do Citoesqueleto/genética , Matriz Extracelular/genética , Matriz Extracelular/metabolismo , Feminino , Humanos , Neoplasias Pulmonares/patologia , Masculino , Proteínas de Membrana/genética , Camundongos Transgênicos , Mitocôndrias/metabolismo , Proteínas Musculares/genética , Proteínas de Neoplasias/genética , Pirrolina Carboxilato Redutases/genética , Pirrolina Carboxilato Redutases/metabolismo , delta-1-Pirrolina-5-Carboxilato RedutaseRESUMO
Precise control of mesenchymal stem cell (MSC) differentiation is critical for tissue development and regeneration. We show here that kindlin-2 is a key determinant of MSC fate decision. Depletion of kindlin-2 in MSCs is sufficient to induce adipogenesis and inhibit osteogenesis in vitro and in vivo. Mechanistically, kindlin-2 regulates MSC differentiation through controlling YAP1/TAZ at both the transcript and protein levels. Kindlin-2 physically associates with myosin light-chain kinase in response to mechanical cues of cell microenvironment and intracellular signaling events and promotes myosin light-chain phosphorylation. Loss of kindlin-2 inhibits RhoA activation and reduces myosin light-chain phosphorylation, stress fiber formation, and focal adhesion assembly, resulting in increased Ser127 phosphorylation, nuclear exclusion, and ubiquitin ligase atrophin-1 interacting protein 4-mediated degradation of YAP1/TAZ. Our findings reveal a novel kindlin-2 signaling axis that senses the mechanical cues of cell microenvironment and controls MSC fate decision, and they suggest a new strategy to regulate MSC differentiation, tissue repair, and regeneration.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Diferenciação Celular , Linhagem da Célula , Proteínas do Citoesqueleto/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Membrana/metabolismo , Células-Tronco Mesenquimais/metabolismo , Proteínas Musculares/metabolismo , Proteínas de Neoplasias/metabolismo , Fosfoproteínas/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Adipogenia , Animais , Proteínas de Ciclo Celular , Proteínas do Citoesqueleto/deficiência , Proteínas do Citoesqueleto/genética , Adesões Focais/metabolismo , Células HEK293 , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Mecanotransdução Celular , Proteínas de Membrana/genética , Camundongos Knockout , Camundongos Nus , Proteínas Musculares/deficiência , Proteínas Musculares/genética , Cadeias Leves de Miosina/metabolismo , Quinase de Cadeia Leve de Miosina/metabolismo , Proteínas de Neoplasias/genética , Osteogênese , Fosfoproteínas/genética , Fosforilação , Proteínas Repressoras/metabolismo , Nicho de Células-Tronco , Fibras de Estresse/metabolismo , Transativadores , Fatores de Transcrição , Proteínas com Motivo de Ligação a PDZ com Coativador Transcricional , Ubiquitina-Proteína Ligases/metabolismo , Proteínas de Sinalização YAP , Proteína rhoA de Ligação ao GTP/metabolismoRESUMO
Maslinic acid (2α, 3ß-dihydroxyolean-12-en-28-oic acid, MA) was isolated from natural plants and showed anti-cancer activity in rat Pheochromocytoma PC12 cells in our previous studies. We now discover that MA disrupts the interaction between Bcl2 and autophagy scaffold protein Beclin1 in the above cell line, leading to the up-regulation of autophagy. We investigated the effect of MA on the interaction between Bcl2 and Beclin1 by biochemical and biophysical methods in combination with autophagy characterization in the above cell line. Our results suggest that MA may serve as an autophagy activator by directly blocking the Bcl2-Beclin1 interaction to release free Beclin1 required for the recruitment of autophagy positive regulators, implying MA may exert its anti-cancer activity by regulating autophagy.