Impact of Escherichia coli and Lipopolysaccharide on the MAPK Signaling Pathway, MMPs, TIMPs, and the uPA System in Bovine Mammary Epithelial Cells
Year: 2025
Type: article
Abstract: Bovine mastitis is a condition typically induced by various pathogens, with Escherichia coli (E. coli) being a common causative agent known for its propensity to cause persistent infections. In experimental models of bovine mastitis, lipopolysaccharide (LPS), a key component of the E. coli cell wall, is frequently employed as an inducer. The extracellular matrix (ECM) is regulated by MMPs, TIMPs, and the uPA system. They collectively participate in ECM degradation and remodeling and have been identified as promising targets for mastitis treatment. However, investigations into the precise mechanisms underlying E. coli and LPS-induced mastitis, as well as the relationship between bovine mastitis and the MAPK signaling pathway, remain limited. In this study, bovine mammary epithelial cells (BMECs) were treated in vitro with 106 CFU/mL heat-inactivated E. coli, 7.5 µg/mL LPS, or a combination of both. The treatments resulted in varying degrees of activation of the MAPK signaling pathway, specifically ERK1/2, JNK, and P38. BMECs were exposed to MAPK inhibitors (the JNK inhibitor SP600125, the ERK inhibitor PD98059, and the P38 inhibitor SB203580) after treatments with heat-inactivated E. coli (106 CFU/mL), LPS (7.5 µg/mL), or a combination of the two for 6, 12, 24, and 48 h. The mRNA and protein levels of MMP-1, MMP-2, MMP-3, MMP-9, MMP-13, TIMP-1, TIMP-2, uPA, uPAR, and PAI-1 were assessed using RT-qPCR and Western blot analysis. The findings indicated that heat-inactivated E. coli and LPS stimulated the expression of MAPK mRNAs (ERK1/2, P38, and JNK) in BMECs, along with corresponding increases in the phosphorylated proteins. Furthermore, MAPK inhibitors substantially upregulated the expression of TIMP-1, TIMP-2, and PAI-1. However, no significant changes were observed in the mRNA and protein levels of MMP-1, MMP-2, MMP-3, MMP-9, MMP-13, uPA, or uPAR. In conclusion, heat-inactivated E. coli and LPS can activate the MAPK signaling pathway in BMECs. Inhibiting this signaling pathway can modulate the expression of TIMP-1, TIMP -2, and PAI-1 at both mRNA and protein levels.
DOI: 10.3390/ijms26083893
Authors: Yuanyuan Zhang, Yuanyuan Zhang, Yulin Ding, Junxi Liang, Kai Zhang, Hong Su, Daqing Wang, Min Zhang, Feifei Zhao, Zhiwei Sun, Zhimin Wu, Fenglong Wang, Guifang Cao, Yong Zhang, Yong Zhang
Language: English
Subfield: Agronomy and Crop Science
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,499
OpenAlex ID: W4409606855