Nononcogenic restoration of the intestinal barrier by E. coli–delivered human EGF
Mira Yu, Juil Kim, Jung Hoon Ahn, Yuseok Moon
Mira Yu, Juil Kim, Jung Hoon Ahn, Yuseok Moon
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Research Article Microbiology

Nononcogenic restoration of the intestinal barrier by E. coli–delivered human EGF

Abstract

Although mucoactive proteins, such as epidermal growth factor (EGF), could improve clinical outcomes of intestinal ulcerative diseases, their gastrointestinal application is limited because of their proteolytic digestion or concerns about tumor promotion. In the present study, ATP-binding cassette (ABC) transporter–linked secretion of human EGF from probiotic Escherichia coli (EGF-EcN) was created to promote beneficial actions of the EGF receptor, which is notably attenuated in patients with intestinal ulcerative injuries. Preventive and postinjury treatment with EGF-EcN alleviated intestinal ulcers and other readouts of disease severity in murine intestinal ulcer models. EGF-EcN administration promoted the restitutive recovery of damaged epithelial layers, particularly via upward expansion of highly proliferating progenitor cells from the lower crypts. Along with the epithelial barrier benefit, EGF-EcN improved goblet cell–associated mucosal integrity, which controls the access of luminal microbiota to the underlying host tissues. Despite concern about the oncogenic action of EGF, EGF-EcN did not aggravate colitis-associated colon cancer; instead, it alleviated protumorigenic activities and improved barrier integrity in the lesions. All findings indicate that probiotic bacteria–based precision delivery of human EGF is a promising mucosal intervention against gastrointestinal ulcers and malignant distress through crypt-derived barrier restoration.

Authors

Mira Yu, Juil Kim, Jung Hoon Ahn, Yuseok Moon

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Figure 9

EGF-EcN–mediated actions in cell proliferation in NSAID-induced ulcer.

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EGF-EcN–mediated actions in cell proliferation in NSAID-induced ulcer. T...
Ten-week-old male mice were pretreated twice with vehicle, EcN, and EGF-EcN over 7 days (n = 12). The mice were then treated with 30 mg/kg of indomethacin via gavage. (A) Mouse small intestinal tissues were stained for BrdU incorporation while the nuclei were counterstained with hematoxylin (original magnification, ×200). Scale bar: 100 μm. The BrdU-positive cells per villus were counted and the counts compared (***P < 0.001 and ns using 2-tailed, unpaired Student’s t test). (B) The vertical intestinal villus was divided into the crypt part and the middle villus part. BrdU-positive cells in each part were counted per villus. Results are shown as the box-and-whisker plot (min to max), and different letters represent significant differences between groups (P < 0.05 using 1-way ANOVA with the Newman-Keuls post hoc test). The box plots depict the minimum and maximum values (whiskers), the upper and lower quartiles, and the median. The length of the box represents the interquartile range. (C) IHC staining using anti–p-EGFR antibody was assessed under the microscope (original magnification, ×200). Scale bar: 100 μm. (D) Mouse small intestinal tissue was stained to detect Sox-9 protein and counterstained with hematoxylin. Each histogram represents events at an increasing DAB level. Scale bar: 100 μm. A quantitative comparison is shown in the graphs (C and D, *P < 0.05; **P < 0.01; ***P < 0.001 using 2-tailed, unpaired Student’s t test).