RESUMO
The Hippo pathway fulfills a crucial function in controlling the balance between proliferation, differentiation and apoptosis in cells. Recent studies showed that G protein-coupled receptors (GPCRs) serve as upstream regulators of Hippo signaling, that either activate or inactivate the Hippo pathway via the large tumor suppressor kinase (LATS) and its substrate, the co-transcription factor Yes-associated protein (YAP). In this study, we focused on the Angiotensin II type 1 receptor (AT1R), which belongs to the GPCR family and has an essential role in the control of blood pressure and water homeostasis. We found that Angiotensin II (Ang II) inactivates the pathway by decreasing the activity of LATS kinase; therefore, leading to an enhanced nuclear shuttling of unphosphorylated YAP in HEK293T cells. This shuttling of YAP is actin-dependent as disruption of the actin cytoskeleton inhibited dephosphorylation of LATS and YAP. Interestingly, in contrast to HEK293T cells, podocytes, which are a crucial component of the glomerular filtration barrier, display a predominant nuclear YAP localization in vivo and in vitro. Moreover, stimulation with Ang II did not alter Hippo pathway activity in podocytes, which show a deactivated pathway. Reactivation of the LATS kinase activity in podocytes resulted in an increased cytoplasmic YAP localization accompanied by a strong induction of apoptosis. Thus, our work indicates that the control of LATS activation and subsequent YAP localization is important for podocyte homeostasis and survival.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Fosfoproteínas/genética , Podócitos/metabolismo , Proteínas Serina-Treonina Quinases/genética , Citoesqueleto de Actina/química , Citoesqueleto de Actina/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Angiotensina II/farmacologia , Animais , Apoptose/genética , Linhagem Celular Transformada , Sobrevivência Celular , Regulação da Expressão Gênica , Células HEK293 , Via de Sinalização Hippo , Homeostase , Humanos , Camundongos , Camundongos Transgênicos , Especificidade de Órgãos , Fosfoproteínas/metabolismo , Fosforilação , Podócitos/citologia , Cultura Primária de Células , Proteínas Serina-Treonina Quinases/metabolismo , Transporte Proteico , Receptor Tipo 1 de Angiotensina/genética , Receptor Tipo 1 de Angiotensina/metabolismo , Transdução de Sinais , Fatores de Transcrição , Proteínas de Sinalização YAPRESUMO
Neonatal nurse practitioners are frequently confronted with ethical dilemmas in the NICU. This article reflects on the historical basis of ethical decision making and the issues some novice NNPs face today regarding their participation in the decision-making process. It examines various educational strategies that can be used to help NNPs to develop the skills they need to participate collaboratively in ethical decision making in the NICU. It concludes with recommendations for further research.