Biological characteristics and transcriptomic profile of adipose-derived mesenchymal stem cells isolated from prion-infected murine model

Background: Prion diseases are characterized by accumulation of misfolded host prion proteins (PrP^Sc) that produce aggregates in brain tissue. Mesenchymal stem cells (MSCs) have been identified as potential therapeutic candidates for prion diseases. However, it has been demonstrated that MSCs maintained and expressed PrP^Sc levels following inoculation, raising concerns regarding their safe and effective use in medical applications. Prion infectivity has been reported in fat tissues, thus the response of adipose-derived MSCs (AdMSCs) to prion infection needs to be fully studied. Methods: For this study, we analyzed the properties of AdMSCs isolated from mice infected with the ME7 scrapie strain and compared them with negative controls. We investigated morphology, viability, immunophenotyping, markers of inflammation, migration activity, and neurotrophic factors. RNA sequencing (RNA-Seq) was performed to identify transcriptome profile changes. Results: AdMSCs derived from ME7-infected mice displayed immunophenotypes similar to cells from negative controls, but they were larger with lower viability (p < 0.05). ME7 infection caused higher expression of inflammatory mediators CCL5, TNF-α, C3, and IL6 (p < 0.05 and p < 0.01) and low expression of the stem cell marker, CXCR4 (p < 0.05) which was confirmed by immunofluorescence staining. The results showed decreased migration activity and wound closure ability of AdMSCs isolated from ME7-infected mice as confirmed by Transwell migration and scratch wound assays (p < 0.05 and p < 0.001), respectively. The RNA-Seq results detected 367 differentially expressed genes between AdMSCs from ME7-infected mice and those from the negative controls, and negative regulation of locomotion, extracellular matrix (ECM) organization, collagen-containing ECM, and extracellular structure organization genes were common in AdMSCs from ME7-infected mice. Transcriptomic analysis revealed that pathways enriched in AdMSCs from ME7-infected mice included those involved in the PI3K-Akt signaling pathway, cell adhesion, protein digestion and absorption, and cytokine–cytokine receptor interactions. Interestingly, genes related to the regulation of iron storage, such as Hp and hepcidin, were upregulated in AdMSCs isolated from ME7-infected mice. Conclusions: Based on these data, therapeutic strategies for AdMSCs in prion disease should be further investigated.