title: Heterologous Expression and Delivery of Biologically Active Exendin-4 by Lactobacillus paracasei L14.
abstract: Exendin-4, a glucagon-like protein-1 (GLP-1) receptor agonist, is an excellent therapeutic peptide drug for type 2 diabetes due to longer lasting biological activity compared to GLP-1. This study explored the feasibility of using probiotic Lactobacillus paracasei as an oral vector for recombinant exendin-4 peptide delivery, an alternative to costly chemical synthesis and inconvenient administration by injection. L. paracasei transformed with a plasmid encoding the exendin-4 gene (L. paracasei L14/pMG76e-exendin-4) with a constitutive promotor was successfully constructed and showed efficient secretion of exendin-4. The secreted exendin-4 significantly enhanced insulin secretion of INS-1 β-cells, along with an increment in their proliferation and inhibition of their apoptosis, corresponding to the effect of GLP-1 on these cells. The transcription level of the pancreatic duodenal homeobox-1 gene (PDX-1), a key transcription factor for cellular insulin synthesis and secretion, was upregulated by the treatment with secreted exendin-4, paralleling the upregulation of insulin gene expression. Caco-2 cell monolayer permeability assay showed a 34-fold increase in the transport of exendin-4 delivered by L. paracasei vs. that of free exendin-4 (control), suggesting effective facilitation of exendin-4 transport across the intestinal barrier by this delivery system. This study demonstrates that the probiotic Lactobacillus can be engineered to secrete bioactive exendin-4 and facilitate its transport through the intestinal barrier, providing a novel strategy for oral exendin-4 delivery using this lactic acid bacterium.
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, P. R. China.|Key Laboratory of Functional Dairy, Department of Food Science and Engineering, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, P. R. China.
authors.forename: Zhu
authors.initials: Z
authors.lastname: Zeng
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, P. R. China.|Key Laboratory of Functional Dairy, Department of Food Science and Engineering, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, P. R. China.
authors.forename: Rui
authors.initials: R
authors.lastname: Yu
authors.affiliation: Key Laboratory of Functional Dairy, Department of Food Science and Engineering, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, P. R. China.
authors.forename: Fanglei
authors.initials: F
authors.lastname: Zuo
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, P. R. China.|Key Laboratory of Functional Dairy, Department of Food Science and Engineering, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, P. R. China.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Yangling Zhongyang Joint Ranch Co. Ltd., Beiyang Breeding Area, Yangling Street Agency, Yangling District, Xi'an, P. R. China.
authors.forename: Deju
authors.initials: D
authors.lastname: Peng
authors.affiliation: College of Agriculture and Biotechnology, China Agricultural University, Beijing, P. R. China.
authors.forename: Huiqin
authors.initials: H
authors.lastname: Ma
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, P. R. China.|Key Laboratory of Functional Dairy, Department of Food Science and Engineering, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, P. R. China.
authors.forename: Shangwu
authors.initials: S
authors.lastname: Chen
mesh_terms: D000818:Animals; D017209:Apoptosis; D018938:Caco-2 Cells; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D000077270:Exenatide; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000235:genetics / Q000378:metabolism; D000069980:Lacticaseibacillus paracasei / Q000235:genetics* / Q000378:metabolism*; D010455:Peptides / Q000008:administration & dosage* / Q000235:genetics* / Q000378:metabolism; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011994:Recombinant Proteins / Q000008:administration & dosage* / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects; D014688:Venoms / Q000008:administration & dosage* / Q000235:genetics* / Q000378:metabolism
chemical_list: D018398:Homeodomain Proteins; D007328:Insulin; D010455:Peptides; D012333:RNA, Messenger; D011994:Recombinant Proteins; D015534:Trans-Activators; D014688:Venoms; C084010:pancreatic and duodenal homeobox 1 protein; D000077270:Exenatide