The Effect Of Interleukin 13 And Lysophosphatidic Acid On Type Ⅰ And Type Ⅲ Collagen Synthesis In Human Hepatic Stellate Cell

Objectives:Interleukin-13 is a pleiotropic immune regulatory cytokine which is produced by activated Type 2 helper cells. It can regulate inflammation, mucus production, tissue remodeling and fibrosis. IL-13 plays an important role in the pathogenesis of various diseases characterized by fibrosis, such as hepatic fibrosis, renal fibrosis, cardiac fibrosis, pulmonary fibrosis. In addition, it can enhance fibrosis when it binds with interleukine-13 receptorα1 (IL-13Rα1), so it is an important therapeutic target for these fibrosis diseases.Lysophosphatidic acid (LPA) is a kind of lipide derivant which is acknowledged as the minimum and simplest glycerophosphatide molecule. It can be secreted by fibroblast, platelet, adipose cell, cancer cell and so on. LPA is an important mitogen and has various functions, including facilitating vascular smooth muscle contraction, enhancing platelet aggregation. And it also can inhibit cell proliferation and collagen production.This study is aimed to explore whether IL-13 can enhance the collagen production in human hepatic stellate cells, and whether LPA can down-regulate the collagen production in human hepatic stellate cells, which can provide theory basis and experimental data for clinical therapies of the fibrosis diseases like liver cirrhosis.Methods:1. Activity of LX-2 cells was detected by trypan blue staining.2 .Modality of LX-2 cells was observed by HE staining.3. LX-2 cells were stimulated with LPA in different concentration with different time, and control group was used. The expression of IL-13Rα1 mRNA was evaluated by RT-PCR.4. RT-PCR was adopted to measure the effect of IL-13 and LPA on the expressions of PCOLⅠand PCOLⅢmRNA in LX-2 cells. LX-2 cells were stimulated with different concentrations of LPA at different time points, and the expressions of PCOLⅠand PCOLⅢmRNA were evaluated by RT-PCR. And then it was divided into four groups: the control group, IL-13group, LPA group and IL-13+LPA group. The expression of PCOLⅠand PCOLⅢmRNA was evaluated by RT-PCR.5. The expression of PCOLⅠprotein was evaluated by immunohistochemisty.Results:1. The activity of LX-2 cells was well, and LPA and IL-13 had no toxicity to LX-2 cells.2. The modality of LX-2 cells was stellate, and their nucleus were round or oval form by HE staining.3. RT-PCR results showed that the expression of IL-13Rα1 mRNA was expressed in any concentration of LPA at any time point.4. RT-PCR results showed that PCOLⅠand PCOLⅢmRNA were up-regulated after LX-2 cells were stimulated with IL-13. There was no significant difference in the expression of PCOLⅠand PCOLⅢmRNA of LX-2 cells when they were stimulated with LPA (0.1μM ) at 6h ,12h and 24h by contrast to the control group. PCOLⅠand PCOLⅢmRNA were down-regulated when LX-2 cells were stimulated with LPA (1μM,10μM) at 24h. In addition, the expression of PCOLⅠand PCOLⅢmRNA in IL-13 group was higher than the control group,while the LPA group was lower by contrast to the control group.5. The result of immunohistochemisty demonstrated that the expression of PCOLⅠprotein was consistent with the result of RT-PCR.Conclusions:1. The expression of IL-13Rα1 mRNA has no significant change when LX-2 cells are stimulated by IL-13 and LPA.2. IL-13 can up-regulate the expression of PCOLⅠand PCOLⅢmRNA in LX-2 cells.3. LPA can down-regulate the expression of PCOLⅠand PCOLⅢmRNA in a certain concentration in LX-2 cells.