Original Article
Copyright ©2011 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Jun 7, 2011; 17(21): 2632-2640
Published online Jun 7, 2011. doi: 10.3748/wjg.v17.i21.2632
Keratinocyte growth factor gene therapy ameliorates ulcerative colitis in rats
Chun-Jie Liu, Ji-De Jin, Tong-De Lv, Zu-Ze Wu, Xiao-Qin Ha
Chun-Jie Liu, Zu-Ze Wu, Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
Ji-De Jin, Zu-Ze Wu, Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing 100850, China
Tong-De Lv, Xiao-Qin Ha, Center for Medical Experiment, General Hospital of Lanzhou Military Command, Key Laboratory of Stem Cell and Gene Medicine in Gansu, Lanzhou 730050, Gansu Province, China
Author contributions: Liu CJ, Ha XQ and Wu ZZ contributed equally to this work; Liu CJ, Ha XQ and Wu ZZ designed the research; Liu CJ and Ha XQ performed the experiments; Lv TD and Ha XQ provided new reagents/analytic tools; Liu CJ, Jin JD, Ha XQ and Wu ZZ analyzed the data and wrote the manuscript.
Supported by Postdoctoral Science Foundation of China, No. 20060390192, 200801243; and research grant from Science and Technology Department of Gansu Province, China, No. 0708NKCA128
Correspondence to: Xiao-Qin Ha, MD, Professor of Medicine, Center for Medical Experiment, General Hospital of Lanzhou Military Command, Key Laboratory of Stem Cell and Gene Medicine in Gansu, Binhenan Road #333, Qilihe District, Lanzhou 730050, Gansu Province, China. haxq@yahoo.com
Telephone: +86-931-8994584 Fax: +86-931-2666945
Received: October 5, 2010
Revised: March 23, 2011
Accepted: March 30, 2011
Published online: June 7, 2011
Abstract

AIM: To investigate the effect of keratinocyte growth factor (KGF) gene therapy in acetic acid-induced ulcerative colitis in rat model.

METHODS: The colitis of Sprague-Dawley rats was induced by intrarectal infusion of 1 mL 5% (v/v) acetic acid. Twenty-four hours after exposed to acetic acid, rats were divided into three experimental groups: control group, attenuated Salmonella typhimurium Ty21a strain (SP) group and SP strain carrying human KGF gene (SPK) group, and they were separately administered orally with 10% NaHCO3, SP or SPK. Animals were sacrificed and colonic tissues were harvested respectively on day 3, 5, 7 and 10 after administration. Weights of rats, colonic weight/length ratio and stool score were evaluated. Histological changes of colonic tissues were examined by hematoxylin and eosin (HE) staining method. The expression of KGF, KGF receptor (KGFR) and TNF-α were measured either by enzyme-linked immunosorbent assay or Western blotting. Immunohistochemistry was used to detect the cellular localization of KGFR and Ki67. In addition, superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in the homogenate were measured.

RESULTS: Body weight and colonic weight/length ratio were declined in SPK group compared with SP and control groups (body weight: 272.78 ± 17.92 g vs 243.72 ± 14.02 g and 240.68 ± 12.63 g, P < 0.01; colonic weight/length ratio: 115.76 ± 7.47 vs 150.32 ± 5.99 and 153.67 ± 5.50 mg/cm, P < 0.01). Moreover, pathological changes of damaged colon were improved in SPK group as well. After administration of SPK strain, KGF expression increased markedly from the 3rd d, and remained at a high level till the 10th d. Furthermore, KGFR expression and Ki67 expression elevated, whereas TNF-α expression was inhibited in SPK group. In the group administered with SPK, SOD activity increased significantly (d 5: 26.18 ± 5.84 vs 18.12 ± 3.30 and 18.79 ± 4.74 U/mg, P < 0.01; d 7: 35.48 ± 3.35 vs 22.57 ± 3.44 and 21.69 ± 3.94 U/mg, P < 0.01; d 10: 46.10 ± 6.23 vs 25.35 ± 4.76 and 27.82 ± 6.42 U/mg, P < 0.01) and MDA contents decreased accordingly (d 7: 7.40 ± 0.88 vs 9.81 ± 1.21 and 10.45 ± 1.40 nmol/mg, P < 0.01; d 10: 4.36 ± 0.62 vs 8.41 ± 0.92 and 8.71 ± 1.27 nmol/mg, P < 0.01), compared with SP and control groups.

CONCLUSION: KGF gene therapy mediated by attenuated Salmonella ameliorates ulcerative colitis induced by acetic acids, and it may be a safe and effective treatment for ulcerative colitis.

Keywords: Keratinocyte growth factor; Ulcerative colitis; Gene therapy; Attenuated Salmonella typhimurium