Molecular mechanism of pancreatic b-cell adaptive proliferation: studies during pregnancy in XXXX and in vitro.

@entity4569 @entity5 @entity20885 @entity3695 @entity14026 @entity35 @entity26844 @entity29972
There is a widespread interest in defining factors and mechanisms that stimulate proliferation of pancreatic islet b-cells. Pregnancy is a special period when the pancreatic islet displays a highly reproducible physiological proliferation. However, the molecular mechanism of b-cell proliferation during pregnancy is unclear. Here, we used cDNA expression array to explore gene expression profiles of islet at various stages of pregnancy in @entity35 . Differentially expressed genes related to islet proliferation were screened by bioinformatics methods, and further verified by real-time PCR, RT-PCR, and Western blotting. Compared with control group, expressions of hundreds of genes were changed during pregnancy. The differentially expressed genes related to islet proliferation were mainly distributed in three groups: genes involved in transcription regulator activity, genes involved in apoptosis or @entity5 , and genes for @entity29972 signaling pathway. Among these genes, expressions of @entity26844 , @entity14026 , @entity20885 , b-catenin, and @entity4569 mRNA were up-regulated during pregnancy. A prominent expression of @entity26844 and @entity14026 protein was observed in islets on day 10.5 of pregnancy, i.e., with earlier time phases than proliferation peak. Moreover, we found that @entity3695 (PRL) can increase the proliferation of b-cell in vitro, which is accompanied by up-regulation of @entity14026 and @entity26844 , indicating that they may play a crucial role in PRL-induced pancreatic b-cell growth. In conclusion, our results suggest that the transcription factor @entity26844 , @entity14026 , and @entity29972 pathway may play an important role in adaptive proliferation of pancreatic islets during pregnancy in @entity35 .
