Fig. 1: CXCL10 is highly expressed in ECD patients and is a target of miR-15a-5p.

A Bioinformatics analysis (TargetScan) of the predicted miR-15a-5p binding site in the 3′UTR of the CXCL10 gene. B MiR-15a-5p and secreted CXCL10 expression levels in plasma samples of ECD patients (green) and HC (red). ECD patients exhibit low levels of miR-15a-5p, as measured by qRT-PCR, normalized to cel-miR-39, and high levels of CXCL10 as measured by ELISA assay. C MiR-15a-5p and CXCL10 expression levels in ECD tissue samples and matched tissues from HCs. ECD patients exhibit low levels of miR-15a-5p (top), normalized to cel-miR-39, and high levels of CXCL10 (bottom), normalized to HPRT1, as measured by qRT-PCR. The histograms present the relative expression of miR-15a-5p and CXCL10 from at least 3 experiments. D Representative immunohistochemical images of skin from an ECD patient (left) showing overexpression of CXCL10 (top) and phospho-ERK1/2 (bottom) in neoplastic histiocytes compared to skin from a non-histiocytosis control patient (right) (anti-CXCL10 (IP-10) (top) and anti-phospho-ERK1/2 (bottom); 400× magnification; scale bars = 50 um). E HEK-293 cells were co transfected with miR-15a-5p mimic and reporter plasmid containing the wild-type 3’UTR of the CXCL10 gene. miR-15a-5p reduced luciferase activity by 70%. Data represent means of at least 3 experiments performed in triplicate and normalized to secreted alkaline phosphatase (SEAP). F The expression of miR-15a-5p in HEK-293 post transfection as measured by qRT-PCR. The histogram presents the relative expression of miR-15a-5p as normalized to U6 snRNA from at least 3 experiments. *p < 0.05. HC Healthy control, ECD Erdheim–Chester disease.