RESUMEN
The fecundity of female mammals is resolved by the limited size of the primordial follicle (PF) pool formed perinatally. The establishment of PF pool is accompanied by a significant programmed oocyte death. Long non-coding RNAs (lncRNA) are central modulators in regulating cell apoptosis or autophagy in multiple diseases, however, the significance of lncRNAs governing perinatal oocyte loss remains unknown. Here we find that Yin-Yang 1 (YY1) directly binds to the lncRNA X-inactive-specific transcript (Xist) promoter and facilitates Xist expression in the perinatal mouse ovaries. Xist is highly expressed in fetal ovaries and sharply downregulated along with the establishment of PF pool after birth. Gain or loss of function analysis reveals that Xist accelerates oocyte autophagy, mainly through binding to pre-miR-23b or pre-miR-29a in the nucleus and preventing the export of pre-miR-23b/pre-miR-29a to the cytoplasm, thus resulting in decreased mature of miR-23b-3p/miR-29a-3p expression and upregulation miR-23b-3p/miR-29a-3p co-target, STX17, which is essential for timely control of the degree of oocyte death in prenatal mouse ovaries. Overall, these findings identify Xist as a key non-protein factor that can control the biogenesis of miR-23b-3p/miR-29a-3p, and this YY1-Xist-miR-23b-3p/miR-29a-3p-STX17 regulatory axis is responsible for perinatal oocyte loss through autophagy.
Asunto(s)
Oocitos/fisiología , Procesamiento Postranscripcional del ARN/genética , ARN Largo no Codificante/fisiología , Animales , Animales Recién Nacidos , Autofagia/genética , Células Cultivadas , Regulación hacia Abajo/genética , Femenino , Feto/metabolismo , Células HEK293 , Humanos , Ratones , MicroARNs/genética , MicroARNs/metabolismo , Células 3T3 NIH , Ovario/crecimiento & desarrollo , Ovario/metabolismo , Embarazo , Proteínas Qa-SNARE/genética , Proteínas Qa-SNARE/metabolismo , Transporte de ARN/genética , Regulación hacia Arriba/genética , Factor de Transcripción YY1/fisiologíaRESUMEN
The annexins are a multifamily of calcium-regulated phospholipid-binding proteins. To investigate the roles of annexins in fiber development, four genes encoding putative annexin proteins were isolated from cotton (Gossypium hirsutum) and designated AnnGh3, AnnGh4, AnnGh5, and AnnGh6. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) results indicated that AnnGh3, AnnGh4, and AnnGh5 were preferentially expressed in fibers, while the transcripts of AnnGh6 were predominantly accumulated in roots. During fiber development, the transcripts of AnnGh3/4/5 genes were mainly accumulated in rapidly elongating fibers. With fiber cells further developed, their expression activity was dramatically declined to a relatively low level. In situ hybridization results indicated that AnnGh3 and AnnGh5 were expressed in initiating fiber cells (0-2 DPA). Additionally, their expression in fibers was also regulated by phytohormones and [Ca(2+)]. Subcellular localization analysis discovered that AnnGh3 protein was localized in the cytoplasm. Overexpression of AnnGh3 in Arabidopsis resulted in a significant increase in trichome density and length on leaves of the transgenic plants, suggesting that AnnGh3 may be involved in fiber cell initiation and elongation of cotton.
Asunto(s)
Anexinas/metabolismo , Arabidopsis/crecimiento & desarrollo , Fibra de Algodón , Regulación de la Expresión Génica de las Plantas , Gossypium/genética , Hojas de la Planta/crecimiento & desarrollo , Proteínas de Plantas/metabolismo , Secuencia de Aminoácidos , Anexinas/genética , Arabidopsis/efectos de los fármacos , Arabidopsis/genética , Calcio/farmacología , Citoplasma/efectos de los fármacos , Citoplasma/metabolismo , ADN Complementario/genética , ADN Complementario/aislamiento & purificación , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Genes de Plantas , Gossypium/citología , Gossypium/efectos de los fármacos , Iones , Datos de Secuencia Molecular , Óvulo Vegetal/genética , Óvulo Vegetal/metabolismo , Filogenia , Reguladores del Crecimiento de las Plantas/farmacología , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/genética , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente , Transporte de ARN/efectos de los fármacos , Transporte de ARN/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Alineación de Secuencia , Fracciones Subcelulares/efectos de los fármacos , Fracciones Subcelulares/metabolismo , Zea mays/efectos de los fármacos , Zea mays/metabolismoRESUMEN
MicroRNAs function as gene expression modulators that are critical for mammalian development. Lactoferrin receptor on the apical membrane of enterocytes has been suggested to play key roles in the absorption of lactoferrin-bound iron from breast milk. The objective of this study was to identify mechanisms of microRNA mediated post-transcriptional regulation of the lactoferrin receptor. Sequence analyses revealed that the miR-584 sequence is identical in human, mouse and rat, and there is a conserved region complementary to the seed region (5' nucleotides 2-8) of miR-584 within the lactoferrin receptor mRNA-3'-untranslated region. miR-584 was further found to co-localize with lactoferrin receptor mRNA in mouse small intestine. The 3'-untranslated region of human lactoferrin receptor mRNA was cloned into pGL3-control luciferase reporter vector. By luciferase reporter assays in HEK293 cells, miR-584 mimic specifically repressed the reporter activity in a dose-dependent manner. miR-584 mimic reduced endogenous lactoferrin receptor protein expression in Caco-2 cells, without significantly affecting the mRNA level. We also determined that miR-584 expression is inversely correlated with lactoferrin receptor mRNA and protein expression. Taken together, we propose that miR-584 contributes to the post-transcriptional expression of lactoferrin receptor during the perinatal period. These findings demonstrate a novel example of how microRNAs may be involved in regulation of nutrient metabolism in the newborn.