ATF3 -activated accelerating effect of LINC00941/lncIAPF on fibroblast-to-myofibroblast differentiation by blocking autophagy depending on ELAVL1/HuR in pulmonary fibrosis

Abstract

Idiopathic pulmonary fibrosis (IPF) is characterized by lung scarring and has no effective treatment. Fibroblast-to-myofibroblast differentiation and myofibroblast proliferation and migration are major clinical manifestations of this disease; hence, blocking these processes is a practical treatment strategy. Here, highly upregulated LINC00941/lncIAPF was found to accelerate pulmonary fibrosis by promoting fibroblast-to-myofibroblast differentiation and myofibroblast proliferation and migration. Assay for transposase-accessible chromatin using sequencing and chromatin immunoprecipitation experiments elucidated that histone 3 lysine 27 acetylation (H3K27ac) activated the chromosome region opening in the LINC00941 promoter. As a consequence, the transcription factor ATF3 (activating transcription factor 3) bound to this region, and LINC00941 transcription was enhanced. RNA affinity isolation, RNA immunoprecipitation (RIP), RNase-RIP, half-life analysis, and ubiquitination experiments unveiled that LINC00941 formed a RNA-protein complex with ELAVL1/HuR (ELAV like RNA binding protein 1) to exert its pro-fibrotic function. Dual-fluorescence mRFP-GFP-MAP1LC3/LC3 (microtubule associated protein 1 light chain 3) adenovirus monitoring technology, human autophagy RT 2 profiler PCR array, and autophagic flux revealed that the LINC00941 -ELAVL1 axis inhibited autophagosome fusion with a lysosome. ELAVL1 RIP-seq, RIP-PCR, mRNA stability, and rescue experiments showed that the LINC00941 -ELAVL1 complex inhibited autophagy by controlling the stability of the target genes EZH2 (enhancer of zeste 2 polycomb repressive complex 2 subunit), STAT1 (signal transducer and activators of transcription 1) and FOXK1 (forkhead box K1). Finally, the therapeutic effect of LINC00941 was confirmed in a mouse model and patients with IPF. This work provides a therapeutic target and a new effective therapeutic strategy related to autophagy for IPF. Abbreviations: ACTA2/a-SMA: actin alpha 2, smooth muscle; ATF3: activating transcription factor 3; ATG: autophagy related; Baf-A1: bafilomycin A 1 ; BLM: bleomycin; CDKN: cyclin dependent kinase inhibitor; CLN3: CLN3 lysosomal/endosomal transmembrane protein, battenin; COL1A: collagen type I alpha; COL3A: collagen type III alpha; CXCR4: C-X-C motif chemokine receptor 4; DRAM2: DNA damage regulated autophagy modulator 2; ELAVL1/HuR: ELAV like RNA binding protein 1; EZH2: enhancer of zeste 2 polycomb repressive complex 2 subunit; FADD: Fas associated via death domain; FAP/FAPα: fibroblast activation protein alpha; FOXK1: forkhead box K1; FVC: forced vital capacity; GABARAP: GABA type A receptor-associated protein; GABARAPL2: GABA type A receptor associated protein like 2; IGF1: insulin ...

Danshensu methyl ester enhances autophagy to attenuate pulmonary fibrosis by targeting lncIAPF–HuR complex

“…The receiver operating characteristic curve (ROC) between lncIAPF and FVC shows that the sensitivity and specificity values are 87.5% and 75.0% in patients with IPF, respectively. The area under the ROC curve is 0.879 ( Zhang J et al, 2022 ). In this study, we further proved that the lncIAPF–HuR complex can be a target related to autophagy for drug action.…”

“…Our results indicated that DME weakened HuR stability to promote autophagy via inhibiting lncIAPF stability and transcription. The collected evidence indicates that overexpression or mutation of EZH2, STAT1, and FOXK1 is closely related to the occurrence and poor prognosis of multiple diseases; thus, they are attractive therapeutic targets for the treatment of diseases ( Bowman et al, 2014 ; Kong et al, 2020 ; Patoli et al, 2020 ; Zhang J et al, 2022 ). Our mechanistic dissection revealed that DME inhibits EZH2, STAT1, and FOXK1 to block autophagy flux via weakening lncIAPF–HuR complex stability.…”

lncHUB2: aggregated and inferred knowledge about human and mouse lncRNAs

“…One study found that LINC00941 plays a role in regulating the differentiation of keratinocytes ( 100 ). Another recent study found that upregulated LINC00941 is associated with idiopathic pulmonary fibrosis (IPF), which is an incurable and progressive disease characterized by lung scarring ( 101 ). In IPF, LINC00941 was found to promote the differentiation of fibroblasts as well as increase cell proliferation and migration.…”

Senescent AECⅡ and the implication for idiopathic pulmonary fibrosis treatment

“…Mechanistically, lncIAPF forms a RNA-protein complex with human antigen R (HuR) to block autophagy by controlling the stability of the target genes EZH2 (enhancer of zeste 2 polycomb repressive complex 2 subunit), STAT1 (signal transducer and activators of transcription 1) and FOXK1 (forkhead box K1). Zhang et al have provided preclinical evidence from the mouse models of lung fibrosis and patient samples and proposed pharmacological approaches for inhibiting lncIAPF related to autophagy; these approaches represent promising therapeutic options for IPF ( Zhang et al, 2022 ). However, numerous questions need to be answered.…”