Journal: Aging Cell
Article Title: The Proinflammatory Secretome of Senescent Cells Can Be Controlled by a HIF2A ‐Dependent Upregulation and a FURIN ‐Dependent Cleavage of the ANGPTL4 Secreted Factor
doi: 10.1111/acel.70307
Figure Lengend Snippet: A hypoxia‐like response mediated by HIF2A upregulates ANGPTL4 during senescence. (A) GSEA plots showing enrichment of the HYPOXIA gene set in 3 senescence models: RAS‐induced senescence in IMR90 (IMR90‐RAS) MEK‐induced senescence in human mammary epithelial cells (hMEC_MEK), and etoposide‐induced senescence in WI38 (WI38‐ETO). Normalized Enrichment Score (NES) and FDR q‐value are indicated. (B, C) MRC5 cells were infected with an empty vector (CTRL), or HIF1A (HIF1A OE) and HIF2A (HIF2A OE) expressing vectors. (B) Relative mRNA expression of HIF1A , HIF2A and ANGPTL4 genes by RT‐qPCR. Mean ± SEM of n = 4 independent experiments. Paired one‐way ANOVA values are indicated. (C) Western blot analysis of HIF1A, HIF2A, ANGPTL4 and the loading control TUBULIN. Representative picture of n = 3 independent experiments. (D) HIF2A peaks identified by Cut & Tag at the ANGPTL4 promoter in MRC5 cells infected with HIF2A (HIF2) or control (Babe) retroviral particles. Two independent experiments were performed (HIF2A‐Rep1, HIF2A‐Rep2). Both peaks contain a Hypoxia Response Element (ACGTG). (E) Western blot analysis of ANGPTL4 and the loading control GAPDH during RAF‐induced senescence (OIS). Representative picture of n = 3 independent experiments. (F) MRC5/RAF:ER cells were infected with lentiviral vectors encoding scramble (shSCR) or HIF2A shRNA (shHIF2A) and next treated (+) or not (−) with 4‐OHT to induce senescence (OIS). Relative mRNA expression of HIF2A and ANGPTL4 genes by RT‐qPCR. Mean ± SEM of n = 4 independent experiments. Paired one‐way ANOVA test results are shown. (G) ChIP‐qPCR assay to assess endogenous HIF2A binding on the ANGPTL4 promoter during OIS induced by RAF. Chromatin fractions derived from 4‐OHT‐treated and untreated MRC5/RAF:ER cells were subjected to immunoprecipitation with anti‐HIF2A antibody or IgG control. Primer sets were designed for regions 2179 bp (distal) and 369 bp (proximal) upstream of the ANGPTL4 TSS, and for Actin promoter as a control. Mean ± SEM of n = 3 independent experiments. Paired t ‐test values are indicated. (H) Western blot analysis of ANGPTL4 and the loading control TUBULIN. Representative picture of n = 3 independent experiments.
Article Snippet: The following primary antibodies were used: ANGPTL4 (NBP2‐19016, Novus); tomato (AB0040‐200, Origene); HIF2A (Lau et al. ), p21 (M7202, Dako); γH2AX (2577S, Cell Signaling); CCL3 (2190–1, Proteintech); FURIN (18413–1‐AP Proteintech); and IL1A—Goat Polyclonal mouse‐IL1A (AF‐400‐NA, R&D systems).
Techniques: Infection, Plasmid Preparation, Expressing, Quantitative RT-PCR, Western Blot, Control, Retroviral, shRNA, ChIP-qPCR, Binding Assay, Derivative Assay, Immunoprecipitation