title: Recombinant Lactococcus lactis expressing porcine insulin-like growth factor I ameliorates DSS-induced colitis in mice.
abstract: BACKGROUND
  Insulin-like growth factor I (IGF-I) is one important family of growth factors, which plays key role in intestinal growth, regeneration, and damage repair. However, the low natural abundance of IGF-I limits its research opportunities and practical application in the fields of medicine and animal husbandry. In this study, a tandem repeat strategy was used to express three copies of the same pIGF-I3 protein in L. lactis. The activity of recombinant pIGF-I3 (rpIGF-I3) was further examined by a mouse model of dextran sulfate sodium (DSS)-induced colitis. In addition, the potential of recombinant L. lactis expressing pIGF-I3 to reduce inflammatory disease was evaluated.
  
  
  RESULTS
  pIGF-I3 could be expressed in L. lactis by the detection of SDS-PAGE and Western blot. Experimental colitis was induced in BALB/c mice by administration of 5 % DSS in drinking water, and the clinical symptoms were observed in DSS-treated mice. Oral administration of recombinant L. lactis expressing pIGF-I3 improved the colonic architecture, and significantly reduced the increase of colonic damage score (P < 0.05). Furthermore, recombinant L. lactis expressing pIGF-I3 treatment significantly reduced serum DAO activity and colonic MPO level, and elevated colonic occludin level compared to the DSS group (P < 0.05).
  
  
  CONCLUSIONS
  The pIGF-I3 expressed in L. lactis has good biological activity, and oral administration of recombinant L. lactis expressing pIGF-I3 attenuated the symptoms and development of DSS-induced colitis in mice. These suggested that L. lactis could be a potential host bacterium for production and delivery of IGF-I against intestinal diseases.
authors.affiliation: Institute of Animal Husbandry and Veterinary Science, Zhejiang Academy of Agricultural Sciences, 145 Shiqiao Road, Hangzhou, 310021, Zhejiang, China. liushujie78@126.com.
authors.forename: Shujie
authors.initials: S
authors.lastname: Liu
authors.affiliation: Institute of Animal Husbandry and Veterinary Science, Zhejiang Academy of Agricultural Sciences, 145 Shiqiao Road, Hangzhou, 310021, Zhejiang, China. zjhzlym@126.com.
authors.forename: Yongming
authors.initials: Y
authors.lastname: Li
authors.affiliation: Institute of Animal Husbandry and Veterinary Science, Zhejiang Academy of Agricultural Sciences, 145 Shiqiao Road, Hangzhou, 310021, Zhejiang, China. hljdengbo@126.com.
authors.forename: Bo
authors.initials: B
authors.lastname: Deng
authors.affiliation: Institute of Animal Husbandry and Veterinary Science, Zhejiang Academy of Agricultural Sciences, 145 Shiqiao Road, Hangzhou, 310021, Zhejiang, China. xzwfyz@163.com.
authors.forename: Ziwei
authors.initials: Z
authors.lastname: Xu
mesh_terms: D000818:Animals; D003092:Colitis / Q000139:chemically induced / Q000473:pathology*; D003106:Colon / Q000187:drug effects* / Q000473:pathology; D016264:Dextran Sulfate / Q000009:adverse effects*; D004195:Disease Models, Animal; D005260:Female; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D013294:Lactococcus lactis / Q000235:genetics*; D051379:Mice; D008807:Mice, Inbred BALB C; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D013552:Swine
chemical_list: D011994:Recombinant Proteins; D007334:Insulin-Like Growth Factor I; D016264:Dextran Sulfate