FGL2和miR-21在溃疡性结肠炎患者外周血及肠黏膜组织中的表达研究

溃疡性结肠炎(UC)是临床较为常见的慢性溃疡型疾病,其发病率逐年上升,治愈率较低,易复发,对患者身心健康造成极大威胁[1]。目前,UC发病相关因素尚未明确,学者认为其发病与肠道微生态、炎症、凝血及微小RNA(miRNA)等有关[2]。微小RNA-21(miR-21)在UC相关癌变中表达上调,其可能通过影响上皮细胞凋亡,破坏肠道稳态。

Overexpression of fibrinogen-like protein 2 protects against T cell-induced colitis

AIMTo determine the effect of overexpression of fibrinogen-like protein 2 (FGL2) on regulatory T cell (Treg) and effector T (Teff) cell function on T cell-induced colitis in Rag1-/- mice.METHODSTreg and Teff cells from fgl2-/-, fgl2+/+, and fgl2Tg mice were purified by FACS. They were studied in vitro for immunosuppressive activity and cell proliferation and in vivo for their effects on the development and prevention of T cell-induced colitis in Rag1-/- mice.RESULTSIn vitro, fgl2Tg Treg had enhanced immunosuppressive activity, and fgl2Tg Teff had reduced proliferation to alloantigen stimulation. Transfer of Teff from C57Bl/6J mice (fgl2+/+) into Rag1-/- mice produced both clinical and histologic colitis with dense infiltrates of CD3+ T cells, crypt abscesses and loss of goblet cells. Fgl2Tg Treg prevented the development of T cell-induced colitis, whereas fgl2+/+ and fgl2-/- Treg were only partially protective. In mice that received fgl2Tg Treg, the ratio of Foxp3+ to CD3+ cells was increased both in the colon and in mesenteric lymph nodes, and Teff cell proliferation as determined by staining with Ki67 was reduced. Teff cells from fgl2Tg mice did not produce colitis.CONCLUSIONHere we show that fgl2Tg Teff are hypoproliferative and do not induce colitis. We further demonstrate that fgl2Tg Treg prevent colitis in contrast to fgl2+/+ Treg, which were only partially protective. These studies collectively provide a rationale for exploring the use of FGL2 or Treg expressing high levels of FGL2 in the treatment of inflammatory bowel disease.

Molecular cloning of promoter in human fibrinogenlike protein 2 (hfgl2) gene and functional analysis of its sequence

The aim of this study is to investigate the important regulative elements region which plays an important role on the activation of transcription exerted by the 5' noncoding region of hfgl2 gene in response to HBc and HBx. A series of promoter luciferase report plasmids, in which the hfgl2 gene has been deleted of the 5' and retained the common 3', were constructed. All the plasmids constructed were subjected to electrophoretic analysis and DNA sequencing. A eukaryotic construct expressing HBc or HBx, a luciferase reporter construct containing hfgl2 promoter and aβ-galactosidase (β-gal) plasmid were co-transfected into Chinese hamster ovary (CHO) cells and hepG2 cells, respectively. Luciferase report plasmids containing hfgl2 promoter were successfully constructed, and a serial assays of deletion of hfgl2 gene promoter showed that a strong regulatory region from -817 to -467 (relative to the transcription start site) was responsible for transcription and expression regulation of hfgl2 gene. The important regulative elements region in the promoter of hfgl2 gene was in response to HBc and HBx. which contributes to further pursuit of cis-acting elements and transcriptional factors involved in the transcription of hfgl2 gene.