Open Access

ARTICLE

Metformin alleviates LTA-induced inflammatory response through PPARγ/MAPK/NF-κB signaling pathway in bovine mammary epithelial cells

ABDELAZIZ ADAM IDRISS ARBAB^1,3,#, CHUNQING YIN^4,#, XUBIN LU¹, YAN LIANG¹, ISMAIL MOHAMED ABDALLA¹, AMER ADAM IDRIS³, TIANLE XU^1,2, YONGJIANG MAO¹, ZHANGPING YANG^1,2,*

1 College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
2 Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China
3 Biomedical Research Institute, Darfur College, Nyala, 63313, Sudan
4 Shandong Haiding husbandry Co., Ltd, Jinan, 250100, China

* Corresponding Author: Zhangping Yang,
# These authors contributed equally for this work

(This article belongs to the Special Issue: Decoding Gene (including circRNA, lincRNA miRNA and mRNA) Expression)

BIOCELL 2022, 46(11), 2443-2454. https://doi.org/10.32604/biocell.2022.020865

Received 16 December 2021; Accepted 11 February 2022; Issue published 07 July 2022

Abstract

Mastitis is a common inflammatory cow mammary infection; that causes significant economic loss in dairy industry. Given the interesting connection between metformin’s anti-inflammatory function and mastitis model induced by LTA in pbMECs, our objective was to prove that metformin was beneficial in suppressing proinflammatory response induced by LTA through modulation of mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signaling pathways and activation of peroxisome proliferator-activated receptor-γ (PPARγ) in pbMECs. The proliferation of cells and mRNA expression were measured using EdU assay and quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Immunoblotting and immunofluorescence analysis were conducted to evaluate the expression of target proteins in inflammatory and anti-inflammatory responses to metformin and LTA. Finally, pbMECs were allowed to treat with the PPAR antagonist GW9662, and inflammatory markers were detected in the cells. Our results showed that LTA concentration at 100 µg/mL significantly stimulated the MAPK14, IL-6 and IL-1β mRNA expressions compared to the control cells (P < 0.05) in dose-dependent tests for LTA. Metformin suppressed the phosphorylation expressions of MAPK (ERK1/2, p38, and JNK) in LTA-stimulated pbMECs. Metformin also reduced the protein expression of NF-κB, interleukin-8 (IL-8), interleukin-1β (IL-1β) and interleukin-6 (IL-6) in pbMECs pretreated with LTA. Metformin administration activated PPARγ phosphorylation by up-regulating the expression of PPARγ in LTA-stimulated pbMECs. Treatment with GW9662 resulted in increased IL-6 expression, which was reversed by metformin. These findings collectively indicated that metformin act to attenuate LTA-stimulated inflammatory response in pbMECs by suppressing MAPK and NF-κB activation via a mechanism partially dependent on PPARγ activation. These results suggested that metformin could function as an anti-inflammatory drug

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