Hardwiring tissue-specific AAV transduction in mice through engineered receptor expression.

The development of transgenic mouse models that express genes of interest in specific cell types has transformed our understanding of basic biology and disease. However, generating these models is time- and resource-intensive. Here we describe a model system, SELective Expression and Controlled Transduction In Vivo (SELECTIV), that enables efficient and specific expression of transgenes by coupling adeno-associated virus (AAV) vectors with Cre-inducible overexpression of the multi-serotype AAV receptor, AAVR. We demonstrate that transgenic AAVR overexpression greatly increases the efficiency of transduction of many diverse cell types, including muscle stem cells, which are normally refractory to AAV transduction. Superior specificity is achieved by combining Cre-mediated AAVR overexpression with whole-body knockout of endogenous Aavr, which is demonstrated in heart cardiomyocytes, liver hepatocytes and cholinergic neurons. The enhanced efficacy and exquisite specificity of SELECTIV has broad utility in development of new mouse model systems and expands the use of AAV for gene delivery in vivo.

FERONIA receptor kinase-regulated reactive oxygen species mediate self-incompatibility in Brassica rapa.

Most plants in the Brassicaceae evolve self-incompatibility (SI) to avoid inbreeding and generate hybrid vigor. Self-pollen is recognized by the S-haplotype-specific interaction of the pollen ligand S-locus protein 11 (SP11) (also known as S-locus cysteine-rich protein [SCR]) and its stigma-specific S-locus receptor kinase (SRK). However, mechanistically much remains unknown about the signaling events that culminate in self-pollen rejection. Here, we show that self-pollen triggers high levels of reactive oxygen species (ROS) in stigma papilla cells to mediate SI in heading Chinese cabbage (Brassica rapa L. ssp. pekinensis). We found that stigmatic ROS increased after self-pollination but decreased after compatible(CP)- pollination. Reducing stigmatic ROS by scavengers or suppressing the expression of respiratory burst oxidase homologs (Rbohs), which encode plant NADPH oxidases that produce ROS, both broke down SI. On the other hand, increasing the level of ROS inhibited the germination and penetration of compatible pollen on the stigma, mimicking an incompatible response. Furthermore, suppressing a B. rapa FERONIA (FER) receptor kinase homolog or Rac/Rop guanosine triphosphatase (GTPase) signaling effectively reduced stigmatic ROS and interfered with SI. Our results suggest that FER-Rac/Rop signaling-regulated, NADPH oxidase-produced ROS is an essential SI response leading to self-pollen rejection.

Ethylene negatively mediates self-incompatibility response in Brassica rapa.

Self-incompatibility (SI) is a genetic mechanism most flowering plants adopted to reject self-pollen thus avoid inbreeding. In the Brassicaceae, self-pollen recognition triggers downstream signaling pathways to reject self-pollen. However, the downstream signaling pathways are not very clear. Here we show that ethylene negatively mediates self-incompatibility response of Chinese cabbage (Brassica rapa L. ssp. Pekinensis) via PCD in papilla cells. We found that ethylene signaling genes were upregulated after cross-pollination. Treating stigmas with ethylene, or suppressing the expression of a negative regulator of ethylene signaling, CONSTITUTIVE TRIPLE RESPONSE 1 (CTR1), caused PCD in papilla cells and broke down the self-incompatibility. On the other hand, treating stigmas with ethylene inhibitors, or suppressing the expression of ethylene-responsive factors (ERFs), inhibited PCD in papilla cells and the compatible pollination. Our study identified an additional signaling pathway mediating self-incompatibility responses in the Brassicaceae and also developed a new method in overcoming self-incompatibility to improve the efficiency of inbred line propagation in agriculture practice.

CircRNA_000864 Upregulates B-cell Translocation Gene 2 Expression and Represses Migration and Invasion in Pancreatic Cancer Cells by Binding to miR-361-3p.

BACKGROUND: Pancreatic cancer is a fatal disease with a very poor prognosis due to its characteristic insidious symptoms, early metastasis, and chemoresistance. Circular RNAs (circRNAs) are involved in the development of pancreatic cancer. AIM: Hence, the aim of this study is to elucidate the mechanism of circRNA_000864 in regulating BTG2 expression in pancreatic cancer by binding to miR-361-3p. METHODS: CircRNA_000864, miR-361-3p, and BTG2 expression patterns in the pancreatic cancer tissues were detected by RT-qPCR. Correlation among circRNA_000864, miR-361-3p, and BTG2 was evaluated by RNA-pull down assay, RNA Immunoprecipitation assay, and dual-luciferase reporter gene assay. After ectopic expression and depletion experiments, 5-ethynyl-2'-deoxyuridine assay, Transwell assay, and flow cytometry were employed to assess the cell proliferation, migration and invasion, cell cycle, and apoptosis. Xenotransplantation of nude mice was conducted to detect the effects of circRNA_000864, miR-361-3p, and BTG2 on tumor growth. RESULTS: CircRNA_000864 and BTG2 were poorly expressed, and miR-361-3p was highly expressed in the pancreatic cancer tissues. CircRNA_000864 bound to miR-361-3p could target BTG2. Cell proliferation, migration, and invasion were inhibited, and the cell cycle arrest and apoptosis were stimulated after overexpression of circRNA_000864 or BTG2 or downregulation of miR-361-3p. Overexpression of circRNA_000864 or downregulation of miR-361-3p also decreased the tumor growth in vivo. CONCLUSIONS: Conjointly, our findings elicited that the overexpression of circRNA_000864 could promote BTG2 expression to inhibit pancreatic cancer development by binding to miR-361-3p, which represents an appealing therapeutic target for the treatment of pancreatic cancer.