1. Rat bone mesenchymal stem cells exert antiproliferative effects on nicotine-exposed T cells via iNOS production.
- Author
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Li, Xiaoyan, Xu, Jianying, and Li, Pingping
- Subjects
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MESENCHYMAL stem cells , *BONES , *OBSTRUCTIVE lung diseases , *NITRIC-oxide synthases , *T cells , *PLURIPOTENT stem cells - Abstract
Adoptive transfer of bone marrow-derived mesenchymal stem cells (BMSCs) significantly alleviates smoking-induced chronic obstructive pulmonary disease (COPD) in rats. Considering the critical roles of T cells during COPD development, the present study aimed to further identify the molecular mechanisms underlying the antiproliferative effect of BMSCs on splenic T cells isolated from rats following chronic exposure to nicotine. Splenic T cells were co-cultured with rat BMSCs at various ratios and subsequently, T-cell proliferation was measured using the Cell Counting Kit-8 assay. The effects of the inducible nitric oxide synthase (iNOS) inhibitor N-nitro-L-arginine methylester (L-NAME) and short hairpin (sh)RNA-lentivirus-mediated knockdown of iNOS in BMSCs on T-cell proliferation were evaluated. The expression levels of iNOS and STAT5 phosphorylation in BMSCs and T cells, respectively, were assessed by reverse transcription-quantitative PCR and western blotting. A higher ratio of BMSCs to T cells resulted in increased inhibition of T-cell proliferation; therefore, the ratio of 1:20 was selected for further in vitro experiments. At a dose of 5 µM, L-NAME displayed the strongest ability to reverse the antiproliferative effects of BMSCs in the co-culture system. Both L-NAME treatment and shRNA-mediated knockdown of iNOS expression significantly decreased the suppressive effects of BMSCs, downregulated iNOS expression at the mRNA and protein levels in BMSCs, and enhanced STAT5 phosphorylation in T cells. BMSCs inhibited the proliferation of nicotine-exposed T cells, which was associated with iNOS expression in BMSCs and decreased STAT5 phosphorylation in T cells. The present study indicated the potential mechanisms underlying the beneficial effects of BMSC infusion in patients with chronic smoking-induced COPD and emphysema. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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