RESUMO
BACKGROUND/OBJECTIVES: Inflammatory Bowel Disease (IBD) has rapidly escalated in Asia (including Korea) due to increasing westernized diet patterns subsequent to industrialization. Factors associated with endoplasmic reticulum (ER) stress are demonstrated to be one of the major causes of IBD. This study was conducted to investigate the effect of Lycium barbarum (L. barbarum) on ER stress. MATERIALS/METHODS: Mouse embryonic fibroblast (MEF) cell line and polarized Caco-2 human intestinal epithelial cells were treated with crude extract of the L. chinense fruit (LF). Paracellular permeability was measured to examine the effect of tight junction (TJ) integrity. The regulatory pathways of ER stress were evaluated in MEF knockout (KO) cell lines by qPCR for interleukin (IL) 6, IL8 and XBP1 spliced form (XBP1s). Immunoglobulin binding protein (BiP), XBP1s and CCAAT/enhancer-binding homologous protein (CHOP) expressions were measured by RT-PCR. Scanning Ion Conductance Microscopy (SICM) at high resolution was applied to observe morphological changes after treatments. RESULTS: Exposure to LF extract strengthened the TJ, both in the presence and absence of inflammation. In polarized Caco-2 pretreated with LF, induction in the expression of proinflammatory marker IL8 was not significant, whereas ER stress marker XBP1s expression was significantly increased. In wild type (wt) MEF cells, IL6, CHOP and XBP1 spliced form were dose-dependently induced when exposed to 12.5-50 µg/mL extract. However, absence of XBP1 or IRE1α in MEF cells abolished this effect. CONCLUSION: Results of this study show that LF treatment enhances the barrier function and reduces inflammation and ER stress in an IRE1α-XBP1-dependent manner. These results suggest the preventive effect of LF on healthy intestine, and the possibility of reducing the degree of inflammatory symptoms in IBD patients.
RESUMO
Cancer cells undergo a number of biophysical changes as they transform from an indolent to an aggressive state. These changes, which include altered mechanical and electrical properties, can reveal important diagnostic information about disease status. Here, we introduce a high-throughput, functional technique for assessing cancer cell invasion potential, which works by probing for the mechanically excitable phenotype exhibited by invasive cancer cells. Cells are labeled with fluorescent calcium dye and imaged during stimulation with low-intensity focused ultrasound, a non-contact mechanical stimulus. We show that cells located at the focus of the stimulus exhibit calcium elevation for invasive prostate (PC-3 and DU-145) and bladder (T24/83) cancer cell lines, but not for non-invasive cell lines (BPH-1, PNT1A, and RT112/84). In invasive cells, ultrasound stimulation initiates a calcium wave that propagates from the cells at the transducer focus to other cells, over distances greater than 1 mm. We demonstrate that this wave is mediated by extracellular signaling molecules and can be abolished through inhibition of transient receptor potential channels and inositol trisphosphate receptors, implicating these proteins in the mechanotransduction process. If validated clinically, our technology could provide a means to assess tumor invasion potential in cytology specimens, which is not currently possible. It may therefore have applications in diseases such as bladder cancer, where cytologic diagnosis of tumor invasion could improve clinical decision-making.
