Iturin A Rescued STb-R-Induced Pork Skeletal Muscle Growth Restriction through the Hypothalamic-Pituitary-mTORC1 Growth Axis

• Published in: Animals (Basel) Vol. 12; no. 12; p. 1568
• Main Authors: Ye, Mao, Liu, Zhenhua, Gao, Chunqi, Yan, Huichao, Wang, Xiuqi, Wen, Liufa, Jin, Chenglong
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 17.06.2022; MDPI
• Subjects: Antibiotics; Antibodies; Antiinfectives and antibacterials; Antimicrobial activity; Antimicrobial agents; Antimicrobial peptides; Body weight; Body weight gain; Drug resistance; Escherichia coli; Fluorides; growth axis; Growth hormone-releasing hormone; Growth hormones; Hypothalamus; Insulin; Insulin-like growth factor I; Insulin-like growth factors; Intestine; Iturin A; Laboratory animals; Microscopy; mTORC1; Muscles; Musculoskeletal system; Peptides; pig; Pituitary; Pork; Protein synthesis; Proteins; Skeletal muscle; skeletal muscle growth; Software; Swine; Variance analysis; Weight reduction; Beijing China; United States > US; China
• ISSN: 2076-2615; 2076-2615
• DOI: 10.3390/ani12121568

The engineered STb-Rosetta Escherichia coli (STb-R) was designed to investigate the effects of Iturin A on the skeletal muscle growth of weaned piglets. A total of 28 piglets were randomly divided into 4 groups (7 piglets per group): the control group (100 mL PBS), the Iturin A group (100 mL 320 mg/kg body weight (BW) Iturin A), the STb-R group (100 mL 1 × 1010 CFU/mL STb-R), and the Iturin A + STb-R group (100 mL 320 mg/kg BW Iturin A + 1 × 1010 CFU/mL STb-R). Compared with the control, STb-R-reduced body weight gain were rescued by Iturin A. The semimembranosus muscle weight recovered to normal level in the Iturin A + STb-R group. The level of relevant genes of the growth axis were elevated by Iturin A, including GHRH in the hypothalamus, GHRHR and GH in the pituitary, and GHR, IGF-1 and IGF-1R in the semimembranosus muscle. Moreover, Iturin A increased the mean fiber area and the number of proliferating cells in the semimembranosus muscle, which were decreased by STb-R. Additionally, the mTORC1 pathway was reactivated by Iturin A to relieve the suppression of STb-R. Collectively, the hypothalamic-pituitary growth axis-mediated Iturin A reactivated the mTORC1 pathway to rescue STb-R-restricted pork skeletal muscle growth.