RESUMEN
Ejaculated mammalian spermatozoa contain a complex yet specific population of mRNA. However, the possible roles that mRNA has in early zygotic and embryonic development remain unclear. We found that Dby mRNA is selectively retained in capacitated mouse spermatozoa, and is transferred into the oocyte during fertilization by reverse transcription-polymerase chain reaction even though no DBY protein expression is detected. The cellular location of Dby mRNA is seen in the post-acrosome region, and it comprises nearly half of the mouse spermatozoa in in situ hybridization. In contrast, transcripts of the control gene, Smcy, are not detected in capacitated mouse spermatozoa, although the H-Y antigen encoded by Smcy is expressed on the surface of the spermatozoa. In our microinjection experiment, the zygotic development rate of the as-Dby male pronucleus injection group was significantly lower than that of the as-Smcy male pronucleus injection group (35.9% vs. 95%, P = 0.001) and the as-Dby female pronucleus injection group (35.9% vs. 93.8%, P = 0.001). The rate of male-developed zygotes was also lower than that of the as-Smcy male pronucleus injection group (17.4% vs. 57.9%, P = 0.002) and the as-Dby female pronucleus injection group (17.4% vs. 54.1%, P = 0.002). Thus, we conclude that Dby mRNA is selectively retained in capacitated mouse spermatozoa, and it has an important role in the early zygotic development of male mouse zygotes. This might imply that spermatozoa mRNA is involved in early zygotic and embryonic stages of reproduction.
Asunto(s)
ARN Helicasas DEAD-box/genética , Desarrollo Embrionario , ARN Mensajero/metabolismo , Capacitación Espermática/genética , Cigoto/metabolismo , Animales , Desarrollo Embrionario/efectos de los fármacos , Femenino , Histona Demetilasas , Masculino , Ratones , Antígenos de Histocompatibilidad Menor , Embarazo , Proteínas/genética , ARN sin Sentido/farmacología , Espermatozoides/metabolismo , Testículo/metabolismoRESUMEN
Nicotine is a major component of cigarette smoking which may be involved in the progress of atherogenesis. In order to explain the mechanism of nicotine-induced endothelium dysfunction, we investigated the effects of nicotine on cyclooxygenase-2 (COX-2) and intercellular adhesion molecule-1 (ICAM-1) expression in human umbilical vein endothelial cells (HUVECs). Nicotine treatment increased the expressions of COX-2 at mRNA and protein level in a dose-dependent manner, following prostaglandin E(2) (PGE(2)) release enhancement. Pyrrolidine dithiocarbamate (PDTC, NF-kappaB inhibitor) and alpha-Bungarotoxin (alpha-Btx, nicotinic acetylcholine receptor antagonist) attenuated the nicotine-induced COX-2 expression and PGE(2) production. Furthermore, nicotine-induced ICAM-1 expression was reduced by NS-398 (selective COX-2 inhibitor). Taken together, the present study demonstrated that nicotine-induced COX-2 expression through NF-kappaB activation which mediated by nicotinic acetylcholine receptor and the induction of COX-2 was related to ICAM-1 expression.
Asunto(s)
Ciclooxigenasa 2/biosíntesis , Dinoprostona/biosíntesis , Células Endoteliales/enzimología , Nicotina/farmacología , Agonistas Nicotínicos/farmacología , Western Blotting , Núcleo Celular/química , Núcleo Celular/metabolismo , Células Cultivadas , Ensayo de Cambio de Movilidad Electroforética , Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Inducción Enzimática/efectos de los fármacos , Femenino , Técnica del Anticuerpo Fluorescente , Humanos , Indicadores y Reactivos , Molécula 1 de Adhesión Intercelular/biosíntesis , Antagonistas Nicotínicos/farmacología , Embarazo , Receptores Nicotínicos/efectos de los fármacos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Estimulación Química , Venas Umbilicales/citologíaRESUMEN
Serial analysis of gene expression (SAGE) is a powerful technique for studying gene expression at the genome level. However, short SAGE tags limit the further study of related data. In this study, in order to identify a gene, we developed a semi-nested PCR-based method called the two-step analysis of unknown SAGE tags (TSAT-PCR) to generate longer 3'-end cDNA fragments from unknown SAGE tags. In the procedure, a modified lock-docking oligo(dT) with two degenerate nucleotide positions at the 3'-end was used as a reverse primer to synthesize cDNAs. Afterwards, the full-length cDNAs were amplified by PCR based on 5'-RACE and 3'-RACE. The amplified cDNAs were then used for the subsequent two-step PCR of the TSAT-PCR process. The first-step PCR was carried out at an appropriately low annealing temperature; a SAGE tag-specific primer was used as the sense primer, and an 18 bp sequence (universal primer I) located at the 5'-reverse primer end was used as the antisense primer. After 15-20 PCR cycles, the 3'-end cDNA fragments containing the tag could be enriched, and the PCR products could be used as templates for the second-step PCR to obtain the specific products. The second-step PCR was performed with a SAGE tag-specific primer and a 22-bp sequence (universal primer II) upstream of universal primer I at the 5'-reverse primer with a high annealing temperature. With our innovative TSAT-PCR method, we could easily obtain specific PCR products covering SAGE from those transcripts, especially low-abundance transcripts. It can be used as a method to identify genes expressed in different cell types.