Transient expression of syndecan in mesenchymal cell aggregates of the embryonic kidney.
Transient expression of syndecan in mesenchymal cell aggregates of the embryonic kidney.
复制标题
Syndecan 在胚胎肾间充质细胞聚集体中的瞬时表达。
DOI：
10.1016/0012-1606(92)90130-9
复制
发表时间：
1992
影响因子：
2.7
通讯作者：
Saxén,L
中科院分区：
文献类型：
--
作者：
Vainio,S;Jalkanen,M;Bernfield,M;Saxén,L
胚胎肾间充质诱导后形成细胞聚集体，随后转化为上皮小管。 Syndecan 结合各种基质成分和生长因子，是参与该过程的候选分子。我们通过原位杂交和狭缝印迹分析分析了肾小管形态发生过程中多配体聚糖表达的变化。将多配体聚糖的表达模式与免疫组织化学分析的细胞增殖分布进行比较。此外，在实验诱导的间充质细胞的悬滴培养物中研究了管前聚集体形成过程中多聚糖的表达。 Syndecan mRNA 在诱导前在后肾间质中表达，在肾小管前细胞聚集体形成过程中强烈存在，但在肾单位成熟过程中丢失。对在转滤器条件下培养的肾间充质（11 天肾）进行狭缝印迹分析，异型诱导组织在第一个 24 小时内触发肾间充质中完整的管生成程序，表明未诱导的间充质中存在多聚糖 mRNA，在诱导过程中没有变化。 mRNA 的表达随后受到刺激（第 13 天的肾脏），随后又下降。然而，硫酸盐标记的多癸烷的免疫分离显示，在第一个 24 小时诱导期内，当 DNA 水平仍保持恒定时，诱导的肾间充质受到显着刺激。在诱导或未诱导的间充质细胞解离并重新聚集的悬滴培养物中，仅在诱导和聚集的间充质细胞中检测到多配体聚糖。通过溴脱氧尿苷掺入分析，双重免疫染色证明多聚糖表达与细胞增殖之间存在密切相关性。因此，看来间充质中的多聚糖表达最初是在转录后诱导的，后来是在mRNA水平的分化过程中诱导的。 Syndecan 在早期肾脏形态发生过程中可能具有双重功能；它可能通过其粘附特性参与细胞聚集，并且可能通过结合生长因子促进诱导间充质细胞的增殖。
Induction of the embryonic kidney mesenchyme is followed by formation of cell aggregates which subsequently transform into epithelial tubules. Syndecan, which binds various matrix components and growth factors, is a candidate molecule to be involved in this process. We have analyzed the changes in the expression of syndecan during tubule morphogenesis by usingin situhybridization and slot-blot analysis. The expression pattern of syndecan was compared with the distribution of cell proliferation analyzed by immunohistochemistry. Furthermore, the expression of syndecan during formation of the pretubular aggregates was studied in hanging-drop cultures of experimentally induced mesenchymal cells. Syndecan mRNA was expressed in the metanephric mesenchyme prior to induction, was intensely present during formation of the pretubular cell aggregates, but was lost during maturation of the nephron. Slot-blot analyses of the kidney mesenchymes (11-day kidney) cultured in a transfilter situation with a heterotypic inductor tissue that triggers a complete tubulogenic program in the nephric mesenchyme during the first 24 hr suggested the presence of syndecan mRNA in the uninduced mesenchymes with no change during induction. Expression of mRNA was stimulated later (13-day kidney) followed by subsequent decrease. Immunoisolation of sulfate-labeled syndecan, however, revealed a marked stimulation in the induced kidney mesenchyme during the first 24-hr inductive period when the DNA level still remained constant. In hanging-drop cultures where either induced or uninduced mesenchymal cells were dissociated and reaggregated, syndecan was detected only in the induced and aggregating mesenchymal cells. Double-immunostaining demonstrated a close correlation between syndecan expression and cell proliferation analyzed by bromodeoxyuridine incorporation. Thus, it appears that syndecan expression in the mesenchyme is initially induced post-transcriptionally and later during differentiation at the mRNA level. Syndecan may have a dual function during early kidney morphogenesis; it may be involved in cell aggregation through its adhesive properties, and it may contribute to proliferation of the induced mesenchymal cells by binding growth factors.