Genome-Wide Analysis of the RAV Gene Family in Wheat and Functional Identification of TaRAV1 in Salt Stress.

RAV transcription factors (TFs) are unique to higher plants and contain both B3 and APETALA2 (AP2) DNA binding domains. Although sets of RAV genes have been identified from several species, little is known about this family in wheat. In this study, 26 RAV genes were identified in the wheat genome. These wheat RAV TFs were phylogenetically clustered into three classes based on their amino acid sequences. A TaRAV gene located on chromosome 1D was cloned and named TaRAV1. TaRAV1 was expressed in roots, stems, leaves, and inflorescences, and its expression was up-regulated by heat while down-regulated by salt, ABA, and GA. Subcellular localization analysis revealed that the TaRAV1 protein was localized in the nucleus. The TaRAV1 protein showed DNA binding activity in the EMSA assay and transcriptional activation activity in yeast cells. Overexpressing TaRAV1 enhanced the salt tolerance of Arabidopsis and upregulated the expression of SOS genes and other stress response genes. Collectively, our data suggest that TaRAV1 functions as a transcription factor and is involved in the salt stress response by regulating gene expression in the SOS pathway.

CUL1 Knockdown Attenuates the Adhesion, Invasion, and Migration of Triple-Negative Breast Cancer Cells via Inhibition of Epithelial-Mesenchymal Transition.

Cullin-1 (CUL1) is an important factor for tumor growth and a potential therapeutic target for breast cancer therapy, but the molecular mechanism in triple-negative breast cancer (TNBC) is unknown. In the present study, CUL1 shRNA was transfected into BT549 and MDA-MB-231 breast cancer cells. Cell morphology, adhesion, invasion, and migration assays were carried out in the CUL1 knockdown cells. Additionally, protein expression levels of epithelial-mesenchymal transition (EMT)-related factors, Akt phosphorylation at S473 (pAkt), glycogen synthase kinase-3ß phosphorylation at ser9 (pGSK3ß), cytoplasmic and nuclear ß-catenin, and epidermal growth factor receptor phosphorylation at Tyr1068 (pEGFR) were detected by Western blot analysis. CUL1 knockdown significantly suppressed the adhesion, invasion and migration capabilities of the cells, and decreased the expression of Snail1/2, ZEB1/2, Twist1/2, Vimentin, and increased the expression of Cytokeratin 18 (CK18). Moreover, CUL1 knockdown significantly downregulated the phosphorylated levels of Akt, GSK3ß, and EGFR, inhibiting the translocation of ß-catenin from the cytoplasm to the nucleus. The results indicate that CUL1 knockdown prohibited the metastasis behaviors of breast cancer cells through downregulation (dephosphorylation) of the EMT signaling pathways of EGFR and Akt/GSK3ß/ß-catenin in breast cancer. These results strongly suggested that reinforcement of the EMT might be a key for CUL1 to accelerate TNBC metastasis.

Duodenal-jejunal exclusion improves insulin resistance in type 2 diabetic rats by upregulating the hepatic insulin signaling pathway.

OBJECTIVES: Previous studies have shown duodenal-jejunal exclusion (DJE) results in the rapid resolution of type 2 diabetes; however, the underlying mechanism is unknown. This study aimed to measure the hepatic expression of insulin receptor substrate-2 (IRS-2) and glucose transporter-2 (GLUT-2) in type 2 diabetic rats post-DJE, and to investigate their roles in improved hepatic insulin resistance and glucose intolerance. METHODS: Type 2 diabetic Sprague-Dawley (SD) rats were randomly divided into DJE operation (DO) and control (DC) groups. Normal SD rats were also divided into DJE operation and control groups. Fasting plasma glucose and insulin concentrations were measured, and the quantitative insulin sensitivity check index (QUICKI) and Homeostasis Model Assessment Insulin Resistance (HOMA-IR) were calculated. Eight weeks postoperation, the hepatic IRS-2 and GLUT-2 protein and mRNA levels were measured using western blotting and reverse transcription polymerase chain reaction, respectively. RESULTS: The fasting blood glucose in the DO group decreased from a preoperative level of 20.21 ± 2.14 mmol/L to 8.50 ± 2.19 mmol/L (P < 0.05) 8 wk post-DJE. A change in the QUICKI revealed a dramatic increase, and HOMA-IR showed a significant decrease in the DO group (P < 0.05). Additionally, the IRS-2 and GLUT-2 protein and mRNA levels at 8 wk postoperation were significantly increased in the DO group compared with the DC group. CONCLUSIONS: DJE led to upregulated hepatic IRS-2 and GLUT-2 expression in the hepatic insulin signaling pathway and improved insulin sensitivity in type 2 diabetic rats.