Acta Veterinaria et Zootechnica Sinica ›› 2024, Vol. 55 ›› Issue (1): 311-322.doi: 10.11843/j.issn.0366-6964.2024.01.029

• BASIC VETERINARY MEDICINE • Previous Articles     Next Articles

The Regulation of Calcium-binding Protein S100A4 on Autophagy in THP-1 Cells Infected with Bacillus Calmette-Guérin

LIU Yueyang1, LI Mengyuan1,2, NIE Xueyi1, MA Yabo1, HOU Yuxin1, MA Boli1, YANG Yi1, XU Jinrui1*   

  1. 1. Key Laboratory of Conservation and Utilization of Characteristic Biological Resources in Western China, Ministry of Education, Ningxia University, Yinchuan 750021, China;
    2. Key Laboratory of Modernization of Hui Medicine, Ministry of Education, Ningxia Medical University, Yinchuan 750010, China
  • Received:2023-05-24 Online:2024-01-23 Published:2024-01-24

Abstract: The purpose of this study was to explore the regulatory effect of calcium-binding protein S100A4 on autophagy of human monocyte-macrophage THP-1 cells infected with Bacillus Calmette-Guérin (BCG). BCG infected THP-1 cells at different times (MOI=10). The expressions of S100A4 and LC3 proteins were detected by Western blot, and the number of autophagosomes was observed by transmission electron microscopy (TEM). After BCG infection alone or co-treatment with S100A4 small interfering RNA for 12 h, the mRNA expression of S100A4 and autophagy-related factors, LC3Ⅱ(microtubule-associated protein light chain 3 Ⅱ), Atg7 (autophagy-related gene 7), and Beclin1, were detected by qRT-PCR. The protein expressions of S100A4, LC3Ⅱ, Atg7, and Beclin-1 were detected by Western blot. Autophagy flow was detected by mRFP-GFP-LC3, and spot aggregation of mRFP-LC3 and mRFP-GFP-LC3 was observed by laser confocal microscopy. After BCG was infected with THP-1 cells at different times, the protein expression levels of S100A4 and LC3Ⅱ firstly increased and then decreased with the extension of infection time, and the expression levels were the highest at 12 h (P<0.001), and the number of autophagosomes increased significantly. mRNA levels of S100A4, LC3Ⅱ, Atg7, and Beclin-1 in the siNC+BCG infection group were significantly up-regulated compared with those in the siNC group (P<0.05), S100A4, LC3Ⅱ, Atg7, and Beclin-1 were significantly expressed at mRNA level after BCG and siS100A4 treatment (P<0.05) or very significantly (P<0.01, P<0.001) down-regulated; Protein levels of S100A4, LC3Ⅱ, Atg7, and Beclin-1 increased significantly compared with an uninfected group (P<0.05), the protein expression levels of S100A4, LC3Ⅱ, Atg7, and Beclin-1 were significantly reduced after BCG and siS100A4 treatment (P<0.001); Compared with the uninfected group, the number of autophagosomes in BCG group was significantly increased (P<0.01), the number of autophagosomes in siS100A4+BCG group was significantly reduced compared with siNC+BCG infection group (P<0.05). S100A4 has a regulatory effect on the autophagy of macrophages induced by BCG infection, and S100A4 can promote the BCG-induced autophagy of THP-1 cells.

Key words: Mycobacterium tuberculosis, autophagy, S100A4, THP-1 cells

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