zebrafish agr2 is required for terminal differentiation of intestinal goblet cells斑马鱼agr2需要终端分化的肠道杯状细胞.pdfVIP

Zebrafish Agr2 Is Required for Terminal Differentiation of Intestinal Goblet Cells 1 1 2 1 Yi-Chung Chen , Yu-Fen Lu , I-Chen Li , Sheng-Ping L. Hwang * 1 Institute of Cellular and Organismic Biology (ICOB), Academia Sinica, Taipei, Taiwan, Republic of China, 2 Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan, Republic of China Abstract Background: Mammalian Anterior Gradient 2 (AGR2) is a protein disulfide isomerase that is required for the production of intestinal mucus and Paneth and goblet cell homeostasis. However, whether increased endoplasmic reticulum (ER) stress occurs in Agr2 2/ 2 mice remains a controversial issue. Methodology/Principal Findings: We characterized the function of zebrafish agr2 by both morpholino antisense oligomer- mediated knockdown and agr2 mRNA overexpression. Fluorescent whole-mount double in situ hybridization indicated that in the intestine, agr2 was only expressed in goblet cells. Significantly increased numbers of immature Alcian blue-stained goblet cells were observed in the intestines of 104- and 120-hours post fertilization (hpf) agr2 morphants. Transmission electron microscopy analyses further confirmed the existence of immature pre-goblet cells containing few mucous granules in the mid-intestines of 104- and 120-hpf agr2 morphants. agr2 expression was not significantly induced by an ER stress inducer, tunicamycin. Expression of the ER chaperone gene hspa5, the spliced form of xbp1s, c/enhancer binding protein homologous protein chop, and the activating transcription factor 4b1 atf4b1 were not significantly induced in either 104-hpf agr2 morphants or agr2-overexpressed embryos. Similar percentages of P-Histone H3-stained M phase cells were identified in intestines of 104-hpf agr2 morpha