Unraveling the expression of microRNA‐27a* & NKG2D in peripheral blood mononuclear cells and natural killer cells of pediatric systemic lupus erythematosus patients

Background and aim The activity of natural killer ( NK ) cells is known to be decreased in systemic lupus erythematosus ( SLE ) patients. Nevertheless, the exact contribution of NK cells in the pathogenesis of SLE is still inconclusive. Micro RNA s (mi RNA s), are small noncoding RNA molecules that play a fundamental role in regulating NK cell function. The objective of this study was to investigate the expression of mi RNA s that might potentially target an essential activating receptor, NKG 2D in peripheral blood mononuclear cells ( PBMC s) and NK cells of SLE patients. Methods In silico analysis revealed miR‐27a* to potentially target NKG 2D messenger RNA ( mRNA ), hence PBMC s and NK cells were isolated from blood samples of SLE patients and healthy controls. Next, the cells were transfected using mimics and antagomirs, after which mi RNA / mRNA were quantified using real time quantitative reverse transcription polymerase chain reaction. Results The results of this study showed that miR‐27a* is overexpressed in the PBMC s and NK cells of SLE patients. In contrast, NKG 2D was found to be downregulated in PBMC s and NK cells of SLE patients. Forcing the expression of miR‐27a* in PBMC s and NK cells enhances the expression of NKG 2D in SLE patients. Furthermore, the ligand of NKG 2D, ULBP 2, was found to be downregulated in the PBMC s of SLE patients. Conclusion The altered expression of the triad, miR‐27a* as well as NKG 2D and ULBP 2, is thought to be characteristic for NK cells in SLE patients. Hence, the ability of miR‐27a* to alter the expression of NKG 2D may provide a new groundwork for understanding the role of mi RNA s in NK cells of SLE patients.