[Genome-wide analysis and functional prediction of the Trihelix transcription factor family in rice].

The Trihelix transcription factor family plays an essential role in plant growth, development and stress response. However, the studies about identification and analysis of this gene family in rice on the genome-wide level have not been reported. In this study, 31 members of the Trihelix family, which contain highly conserved and characteristic trihelix domain through sequence clustering and functional domains analysis, were identified in rice genome database using bioinformatic tools. These members could be classified into 5 subfamilies (I~V) based on the evolutionary relationship and domain characteristics. Clustering analyses of the Trihelix family in rice, Arabidopsis, Brachypodium distachyom and Sorghum bicolor showed that each species contained different members of subfamily although the classification of the Trihelix family were consistent in these four species, which indicated that the differentiation of the Trihelix gene family occur earlier than that of these species. The conserved motifs in the Trihelix family of rice analyzed using the MEME program were highly consistent with the results of clustering analyses. Intraspecific and interspecific chromosomal replication in partial Trihelix family members were found to exist in rice and between rice and other species through chromosome replication analysis. Microarray data analysis revealed diverse expression patterns of Trihelix family genes in different tissues of rice or in response to six different phytohormones. Moreover, 20 members of the Trihelix transcription factor family were found to interact with other proteins in rice using RiceFRIEND online database analysis. Therefore, our results preliminarily identified the evolution, chromosome distribution and replication, expression patterns, phytohormones response of the Trihelix transcription factor family and the interaction between trihelix family proteins and other proteins in rice, which will provide a basis to further reveal the molecular evolution and biological function of the Trihelix transcription factor family.

Inhibition of Notch Signaling Promotes the Adipogenic Differentiation of Mesenchymal Stem Cells Through Autophagy Activation and PTEN-PI3K/AKT/mTOR Pathway.

BACKGROUND: The Notch signaling pathway is implicated in a broad range of developmental processes, including cell fate decisions. This study was designed to determine the role of Notch signaling in adipogenic differentiation of human bone marrow derived MSCs (BM-MSCs). METHODS: The Notch signaling was inhibited by the γ-secretase inhibitor N-[N-(3,5-difluor- ophenacetyl-L-alanyl)]-S-phenylglycine t-butylester (DAPT). The markers involving adipogenic differentiation of MSCs, the relative pathway PTEN-PI3K/Akt/mTOR and autophagy activation were then analyzed. Furthermore, the autophagy inhibitor chloroquine (CQ) and 3-methyladenine (3-MA) were used to study the role of autophagy in the DAPT-induced the adipogenic differentiation of MSCs. RESULTS: We first confirmed the down -regulation of Notch gene expression during MSCs adipocyte differentiation, and showed that the inhibition of Notch signaling significantly enhanced adipogenic differentiation of MSCs. Furthermore, Notch inhibitor DAPT induced early autophagy by acting on PTEN-PI3K/Akt/mTOR pathway. The autophagy inhibitor CQ and 3-MA dramatically abolished the effects of DAPT-induced autophagy and adipogenic differentiation of MSCs. CONCLUSION: Our results indicate that inhibition of Notch signaling could promote MSCs adipogenesis mediated by autophagy involving PTEN-PI3K/Akt/mTOR pathway. Notch signaling could be a novel target for regulating the adipogenic differentiation of MSCs.