Pmepa1 knockdown alleviates SpA-induced pyroptosis and osteogenic differentiation inhibition of hBMSCs via p38MAPK/NLRP3 axis

Mingjun Li; Xiangwen Shi; Yipeng Wu; Baochuang Qi; Chaoqun Zhang; Bin Wang; Bihuan Zhang; Yongqing Xu

doi:10.1016/j.intimp.2023.110843

Pmepa1 knockdown alleviates SpA-induced pyroptosis and osteogenic differentiation inhibition of hBMSCs via p38MAPK/NLRP3 axis

Int Immunopharmacol. 2023 Nov;124(Pt A):110843. doi: 10.1016/j.intimp.2023.110843. Epub 2023 Aug 25.

Authors

Mingjun Li¹, Xiangwen Shi¹, Yipeng Wu², Baochuang Qi¹, Chaoqun Zhang¹, Bin Wang¹, Bihuan Zhang¹, Yongqing Xu³

Affiliations

¹ Kunming Medical University, Kunming, Yunnan 650500, China.
² Department of Orthopedic Surgery, 920th Hospital of Joint Logistics Support Force, Kunming, China.
³ Department of Orthopedic Surgery, 920th Hospital of Joint Logistics Support Force, Kunming, China. Electronic address: xuyongqingynkm@163.com.

PMID: 37634444
DOI: 10.1016/j.intimp.2023.110843

Abstract

Background: Osteomyelitis is a refractory bone infectious disease, which usually results in progressive bone destruction and bone loss. The invasion of pathogens and subsequent inflammatory response could damage bone marrow mesenchymal stem cells (BMSCs) and inhibit osteogenic differentiation, and finally aggravate uncontrolled bone remodeling in osteomyelitis by affecting bone formation. Exploring the mechanisms of BMSCs injury and osteogenic differentiation inhibition may would help us to find potential therapeutic targets.

Method: Firstly, staphylococcal protein A (SpA)-treated human bone marrow mesenchymal stem cells (hBMSCs) were used to construct cell models of osteomyelitis. Secondly, transcriptome sequencing was performed to screen differentially expressed genes and then verified the expression of target genes. Next, in vitro experiments were conducted to explore the functions and mechanisms of prostate transmembrane protein androgen induced 1 (Pmepa1) in SpA-treated hBMSCs. Finally, the rat model of osteomyelitis was established to provide an auxiliary validation of the in vitro experimental results.

Results: We found that SpA treatment induced inflammatory injury and inhibited osteogenic differentiation in hBMSCs, then the transcriptome sequencing and further detection results showed that Pmepa1 was significantly upregulated in this process. Functionally, Pmepa1 knockdown alleviated inflammatory injury and promoted osteogenic differentiation in SpA-treated hBMSCs. Among them, it was demonstrated that Pmepa1 knockdown exerted cytoprotective effects by alleviating pyroptosis of SpA-infected hBMSCs. Furthermore, recovery experiments revealed that Pmepa1 knockdown reversed SpA-mediated adverse effects by downregulating the p38MAPK/NLRP3 axis. Finally, the detection results of rat femoral osteomyelitis showed that the expression of Pmepa1 was up-regulated, and the expression trends of other indicators including p38MAPK, NLRP3, and caspase-1 were also consistent with the in vitro model.

Conclusion: Pmepa1 knockdown alleviates SpA-induced pyroptosis and inhibition of osteogenic differentiation in hBMSCs by downregulating p38MAPK/NLRP3 signaling axis. Modulating the expression of Pmepa1 may be a potential strategy to ameliorate osteomyelitis.

Keywords: Human bone marrow mesenchymal stem cells (hBMSCs); Osteogenic differentiation; Osteomyelitis; Pmepa1; Pyroptosis.