RESUMEN
The Wnt and Notch1 signaling pathways play major roles in intestinal development and tumorigenesis. Sub-cellular localization of ß-catenin has been implicated in colorectal carcinogenesis. However, the ß-catenin and Notch intracellular domain (NICD) interaction has to be addressed. Immunohistochemistries of ß-catenin, NICD, and dual immunofluorescence of ß-catenin and NICD were analyzed in colorectal tissues and HT29 cell line. Moreover, real-time PCR analysis of CyclinD1, Hes1 and MUC2 was done in HT29 cells upon N-[N-(3, 5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT) treatment. Dual staining emphasized the strong interaction of ß-catenin and NICD in adenoma and adenocarcinoma than in normal tissues. Hes1 transcript levels were decreased 1.5- and 7.1-fold in 12.5 and 25 µM DAPT-treated HT29 cells. CyclinD1 transcript levels decreased 1.2- and 1.6-fold, and MUC2 transcript level increased 4.3- and 7.5-fold in 12.5 and 25 µM DAPT-treated HT29 cells. The results of this study showed that the sub-cellular localization of ß-catenin converges with NICD inducing proliferation through the activation of CyclinD1 and Hes1. Moreover, the inhibition of Notch1 signaling by DAPT leads to the arrest of cell proliferation and induces apoptosis leading to the upregulation of MUC2, a secretory cell lineage marker.
Asunto(s)
Neoplasias del Colon/metabolismo , Neoplasias del Colon/patología , Ciclina D1/metabolismo , Receptor Notch1/metabolismo , beta Catenina/metabolismo , Adenocarcinoma/metabolismo , Adenocarcinoma/patología , Adenoma/metabolismo , Adenoma/patología , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Proliferación Celular , Neoplasias del Colon/genética , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Ciclina D1/genética , Dipéptidos/farmacología , Relación Dosis-Respuesta a Droga , Regulación Neoplásica de la Expresión Génica , Células HT29/efectos de los fármacos , Células HT29/metabolismo , Proteínas de Homeodominio/genética , Humanos , Mucina 2/genética , Mucina 2/metabolismo , Estructura Terciaria de Proteína , Valores de Referencia , Transducción de Señal , Factor de Transcripción HES-1RESUMEN
INTRODUCTION: The origin of heart-forming cells and their roles in organ development have fascinated biologists for over a century. C-X-C chemokine receptor type 4 plays a crucial role during embryonic development and in maintaining the stem cell niche and homing. The aim of the present was to study the expression pattern of resident cardiac stem cell markers and their homing factor in neonatal, postnatal, and adult mouse heart. METHODS: Cardiac stem cell protein expression was analyzed using immunofluorescence, immunohistochemistry, and Western blotting. The messenger ribonucleic acid expression of cardiac stem cell markers c-kit, stem cell antigen-1, and homing factor C-X-C chemokine receptor type 4 was quantitatively analyzed using quantitative polymerase chain reaction. Data were analyzed using Student's t test and two-way analysis using SPSS software. RESULTS: Stem cell antigen-1- and c-kit-positive cell populations were heterogeneously distributed in the adult and postnatal hearts but scattered in the neonatal heart. The expression of c-kit showed a significant difference between right and left atrium, though it was higher compared to ventricles. The homing factor C-X-C chemokine receptor type 4 expression was higher in the neonatal heart than in the postnatal heart but was not detectable in the adult heart. CONCLUSIONS: The present study reveals the distribution of cardiac stem cells in the different compartments of the heart and significant reduction in their number in adult heart. Cardiac stem cells are higher in the atrium than in the ventricle, suggesting the atria as the source of cardiac stem cell.
Asunto(s)
Antígenos Ly/metabolismo , Quimiotaxis , Proteínas de la Membrana/metabolismo , Miocardio/metabolismo , Proteínas Proto-Oncogénicas c-kit/metabolismo , Receptores CXCR4/metabolismo , Células Madre/metabolismo , Factores de Edad , Envejecimiento/metabolismo , Animales , Animales Recién Nacidos , Biomarcadores/metabolismo , Western Blotting , Técnica del Anticuerpo Fluorescente , Atrios Cardíacos/citología , Atrios Cardíacos/metabolismo , Ventrículos Cardíacos/citología , Ventrículos Cardíacos/metabolismo , Inmunohistoquímica , Masculino , Ratones , Miocardio/citología , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptores CXCR4/genética , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
Vitellogenin (VTG) synthesis in the hepatopancreas and ovary is negatively regulated by vitellogenesis-inhibiting hormone (VIH) produced in the neurosecretory cell of X-organ/sinus gland complex of the eyestalks of penaeid shrimp. Eyestalk ablation is used commercially to induce ovarian maturation in shrimps which leads to an eventual loss of the spawner. The aim of the present study was to understand the molecular mechanism of VIH regulation in ovarian development and its inhibition of VTG gene expression by using a MEK-specific inhibitor (U0126). The real-time quantitative PCR results showed VTG mRNA level was progressively increased in the ovary and hepatopancreas of unilateral eyestalk-ablated and inhibitor-treated shrimps. Western blot analysis also showed that phosphoMEK was detected only in the unilateral eyestalk-ablated and control shrimp, whereas phospho-MEK was not detected in inhibitor-treated shrimp. DAX-1, SF-1, and StAR expression correlated with changes in VIH mRNA and altered phospho-ERK levels. This is consistent with the hypothesis that suppression of DAX-1 results in SF-1-mediated StAR protein upregulation of estradiol that is implicated in vitellogenesis. This is the first report that demonstrates the molecular mechanism of VIH suppression via MEK pathway to induce ovarian maturation in female Penaeus monodon by molecular signal intervention, a less-invasive method than traditional eyestalk ablation.