Figure 3.

GATA4 induced by cGAS-STING stimulation is upregulated in senescent SLE monocytes. (A) SLE or HC monocytes were untreated or stimulated with 2′3′-cGAMP. IFNA1, GATA4, and CDKN2A expressions were quantified by RT-qPCR. The 2^-ΔΔCT method was used to calculate the relative gene expression, with normalization to GAPDH as the internal control. Open circles indicate no amplification by RT-qPCR. (The boxplots indicate the median, 25th percentile, and 75th percentile, and whiskers indicate the minimum and maximum values. *P<0.05, **P<0.01, and ****P<0.0001 by the Mann-Whitney U-test). (B, C) Immunofluorescence images showing GATA4 (red) staining of monocytes stimulated with 2′3′-cGAMP (B) or p16 (red) staining of monocytes, with and without 2′3′-cGAMP stimulation (C). Cell nuclei were stained with DAPI. Representative images from HC and SLE are shown. The figure shows merged images in the upper panel, with magnified views of the indicated cells (white arrow) in the lower panel. Images correspond to DAPI (blue), GATA4 or p16 (red), and merged channels. (D) SA-β-Gal activity in HC and SLE monocytes was measured by flow cytometry. Histograms are representative examples of SA-β-Gal activity in HC and SLE monocytes. The boxplots indicate the median, 25th percentile, and 75th percentile, and whiskers indicate the minimum and maximum values. *P<0.05, by the Mann-Whitney U-test.