За кадры. 1981. № 39 (2336)

Под небом РодиныАндрей Зайцев подает пример / Л. СоловьеваК трудовому семестру готовы / А. ТумановВсе флаги в гости... / А. А. КаплинДом под общей крышей / Р. ГорскаяОтстающие подвели / О. Ольшевская, С. ЧернышеваСдать без троек! / А. ГагаринАттестация в обучении. 1. Информация для обсуждения / В. ШнейдерНужная книга и добрый советВпереди - практика / А. КузнецоваПамятная встречаС хозяйским подходом / Г. М. КассировРекомендовано к испытанию / П. ШеринНа площадке строителей / Е. КатюхинаСлет туристов / С. КуксинНа пьедестале почетаЕсть еще резервы / Б. АнаньеваПраздник эсперанто / М. ШляферБлагодарность / Е. ПетраковскаяСтуденты помогли / Н. ТрофимоваНе бросайте друзе

Albumin and alpha-fetoprotein gene expression in various nonhepatic rat tissues.

International audienceAlbumin and alpha-fetoprotein (AFP), two major serum proteins, are synthesized predominantly in the liver and yolk sac of mammals. In the present paper we report on the developmental expression of the corresponding genes in nonhepatic rat tissues. Significant quantities of mature albumin and AFP mRNAs were revealed in kidney, pancreas, heart, and lung of fetal and/or newborn rats using dot blot and Northern blot assays. Very low levels of these mRNA sequences were also detected in adult kidney and pancreas using sensitive RNA-cDNA solution hybridization assays. In situ hybridization analysis revealed that the albumin and AFP gene transcripts are present in the tubular cells of the 20-day-old fetal kidney. In order to elucidate further the mechanisms governing this expression, we studied the chromatin structure and methylation pattern in the 5'-end of these two genes. A faint band, corresponding to a specific DNase I-hypersensitive site upstream from the albumin gene, was detected in the fetal and neonatal kidney nuclei but not in adult kidney. For both genes, a site CG, demethylation of which is correlated with expression in liver and hepatoma cell lines, is highly methylated in fetal kidney even though AFP and albumin genes are expressed. Taken together, these results show the presence of a cell population in the rat kidney that actively transcribes both the albumin and AFP genes. The expression of these genes may be mediated by mechanisms differing in at least some steps from those exerted in the liver

Albumin and alpha-fetoprotein gene expression in various nonhepatic rat tissues.

International audienceAlbumin and alpha-fetoprotein (AFP), two major serum proteins, are synthesized predominantly in the liver and yolk sac of mammals. In the present paper we report on the developmental expression of the corresponding genes in nonhepatic rat tissues. Significant quantities of mature albumin and AFP mRNAs were revealed in kidney, pancreas, heart, and lung of fetal and/or newborn rats using dot blot and Northern blot assays. Very low levels of these mRNA sequences were also detected in adult kidney and pancreas using sensitive RNA-cDNA solution hybridization assays. In situ hybridization analysis revealed that the albumin and AFP gene transcripts are present in the tubular cells of the 20-day-old fetal kidney. In order to elucidate further the mechanisms governing this expression, we studied the chromatin structure and methylation pattern in the 5'-end of these two genes. A faint band, corresponding to a specific DNase I-hypersensitive site upstream from the albumin gene, was detected in the fetal and neonatal kidney nuclei but not in adult kidney. For both genes, a site CG, demethylation of which is correlated with expression in liver and hepatoma cell lines, is highly methylated in fetal kidney even though AFP and albumin genes are expressed. Taken together, these results show the presence of a cell population in the rat kidney that actively transcribes both the albumin and AFP genes. The expression of these genes may be mediated by mechanisms differing in at least some steps from those exerted in the liver

Concomitant multipotent and unipotent dental pulp progenitors and their respective contribution to mineralised tissue formation

Upon in vitro induction or in vivo implantation, the stem cells of the dental pulp display hallmarks of odontoblastic, osteogenic, adipogenic or neuronal cells. However, whether these phenotypes result from genuine multipotent cells or from coexistence of distinct progenitors is still an open question. Furthermore, determining whether a single cell-derived progenitor is capable of undergoing a differentiation cascade leading to tissue repair in situ is important for the development of cell therapy strategies. Three clonal pulp precursor cell lines (A4, C5, H8), established from embryonic ED18 first molars of mouse transgenic for a recombinant plasmid adeno-SV40, were induced to differentiate towards the odonto/osteogenic, chondrogenic or adipogenic programme. Expression of phenotypic markers of each lineage was evaluated by RT-PCR, histochemistry or immunocytochemistry. The clones were implanted into mandibular incisors or calvaria of adult mice. The A4 clone was capable of being recruited towards at least 3 mesodermal lineages in vitro and of contributing to dentin-like or bone formation, in vivo, thus behaving as a multipotent cell. In contrast, the C5 and H8 clones displayed a more restricted potential. Flow cytometric analysis revealed that isolated monopotent and multipotent clones could be distinguished by a differential expression of CD90. Altogether, isolation of these clonal lines allowed demonstrating the coexistence of multipotential and restricted-lineage progenitors in the mouse pulp. These cells may further permit unravelling specificities of the different types of pulp progenitors, hence facilitating the development of cell-based therapies of the dental pulp or other cranio-facial tissues