RESUMO
Members of the transforming growth factor-ß superfamily play essential roles in various aspects of embryonic development and physiological organ function. Among them, bone morphogenetic protein (BMP) 9 and BMP10 regulate embryonic vascular development by activating their endothelial receptor ALK1 (activin receptor-like kinase 1, also called Acvrl1). ALK1-mediated intracellular signaling is implicated in the etiologies of human diseases, but their downstream functional proteins are largely unknown. In this study, we identified Tmem100, a gene encoding a previously uncharacterized intracellular transmembrane protein, to be an embryonic endothelium-enriched gene activated by BMP9 and BMP10 through the ALK1 receptor. Tmem100 null mice showed embryonic lethality due to impaired differentiation of arterial endothelium and defects of vascular morphogenesis, which phenocopied most of the vascular abnormalities observed with the Acvrl1/Alk1 deficiency. The activity of Notch- and Akt-mediated signaling, which is essential for vascular development, was down-regulated in Tmem100 null mice. Cre-mediated deletion of Tmem100 in endothelial cells was sufficient to recapitulate the null phenotypes. These data indicated that TMEM100 may play indispensable roles downstream of BMP9/BMP10-ALK1 signaling during endothelial differentiation and vascular morphogenesis.
Assuntos
Receptores de Ativinas Tipo I/metabolismo , Artérias/embriologia , Diferenciação Celular/fisiologia , Endotélio Vascular/embriologia , Regulação da Expressão Gênica no Desenvolvimento/genética , Proteínas de Membrana/metabolismo , Morfogênese/fisiologia , Receptores de Activinas Tipo II , Animais , Artérias/citologia , Northern Blotting , Southern Blotting , Western Blotting , Proteínas Morfogenéticas Ósseas/metabolismo , Endotélio Vascular/citologia , Fator 2 de Diferenciação de Crescimento/metabolismo , Imuno-Histoquímica , Hibridização In Situ , Camundongos , Camundongos Endogâmicos BALB C , Análise em Microsséries , Reação em Cadeia da Polimerase em Tempo RealRESUMO
The Hairy-related transcription factor family of Notch- and ALK1-downstream transcriptional repressors, called Hrt/Hey/Hesr/Chf/Herp/Gridlock, has complementary and indispensable functions for vascular development. While mouse embryos null for either Hrt1/Hey1 or Hrt2/Hey2 did not show early vascular phenotypes, Hrt1/Hey1; Hrt2/Hey2 double null mice (H1(ko) /H2(ko) ) showed embryonic lethality with severe impairment of vascular morphogenesis. It remained unclear, however, whether Hrt/Hey functions are required in endothelial cells or vascular smooth muscle cells. In this study, we demonstrate that mice with endothelial-specific deletion of Hrt2/Hey2 combined with global Hrt1/Hey1 deletion (H1(ko) /H2(eko) ) show abnormal vascular morphogenesis and embryonic lethality. Their defects were characterized by the failure of vascular network formation in the yolk sac, abnormalities of embryonic vascular structures and impaired smooth muscle cell recruitment, and were virtually identical to the H1(ko) /H2(ko) phenotypes. Among signaling molecules implicated in vascular development, Robo4 expression was significantly increased and activation of Src family kinases was suppressed in endothelial cells of H1(ko) /H2(eko) embryos. The present study indicates an important role of Hrt1/Hey1 and Hrt2/Hey2 in endothelial cells during early vascular development, and further suggests involvement of Robo4 and Src family kinases in the mechanisms of embryonic vascular defects caused by the Hrt/Hey deficiency.
Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Sistema Cardiovascular/embriologia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Morfogênese/fisiologia , Proteínas Repressoras/metabolismo , Transdução de Sinais/genética , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Western Blotting , Endotélio/metabolismo , Deleção de Genes , Regulação da Expressão Gênica no Desenvolvimento/genética , Imuno-Histoquímica , Hibridização In Situ , Camundongos , Morfogênese/genética , Proteínas do Tecido Nervoso/metabolismo , Receptores de Superfície Celular , Receptores Imunológicos/metabolismo , Proteínas Repressoras/genética , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Differentiated thyroid cancer (DTC) is the most prevalent endocrine malignancy worldwide and requires effective prognostic markers and therapeutic targets to optimize patient outcomes. This study investigated the potential of human serum albumin (HSA) cysteine-34 (Cys34) redox state as a prognostic indicator and therapeutic avenue for DTC. A retrospective cohort study of 99 patients with DTC undergoing radioactive iodine therapy found that higher concentrations of HSA with the reduced form of Cys34 (i.e., human mercaptalbumin [HMA]) were associated with improved progression-free survival in metastatic DTC. In vitro experiments using a DTC cell line revealed that HMA induced cytotoxic effects by triggering ferroptosis, characterized by lipid peroxidation, intracellular ROS accumulation, and decreased cell viability. Ferroptosis inhibitors rescued cell viability, confirming their role in cytotoxicity. These results implicate the HSA-Cys34 redox state is a promising avenue for precision medicine in DTC, shedding light on the prognostic relevance and therapeutic potential of HMA-induced ferroptosis. They emphasize the opportunity for personalized treatment strategies to advance the management of patients with DTC.