Loss of Twist1 in the Mesenchymal Compartment Promotes Increased Fibrosis in Experimental Lung Injury by Enhanced Expression of CXCL12

Abstract

Idiopathic Pulmonary Fibrosis (IPF) is a disease characterized by the accumulation of apoptosis-resistant fibroblasts in the lung. We have previously shown that high expression of the transcription factor twist1 may explain this pro-survival phenotype in vitro. However, this observation has never been tested in vivo. We found that loss of twist1 in COL1A2+ cells led to increased fibrosis characterized by very significant accumulation of T-cells and bone marrow-derived matrix-producing cells. We found that twist1-null cells expressed high levels of the T-cell chemoattractant CXCL12. In vitro, we found that the loss of twist1 in IPF lung fibroblasts increased expression of CXCL12 downstream of increased expression of the non-canonical NF-κB transcription factor RelB. Finally, blockade of CXCL12 with AMD3100 attenuated the exaggerated fibrosis observed in twist1 null mice. Transcriptomic analysis of 134 IPF patients revealed that low expression of twist1 was characterized by enrichment of T-cell pathways. In conclusion, loss of twist1 in collagen-producing cells led to increased bleomycin-induced pulmonary fibrosis, which is mediated by increased expression of CXCL12. Twist1 expression is associated with dysregulation of T-cells in IPF patients. Twist1 may shape the IPF phenotype and regulate inflammation in fibrotic lung injury.

Fibroblast‐specific IL11 signaling drives chronic inflammation in murine fibrotic lung disease

“…We used the Col1a2-CreERT mice as previous reports have shown high fibroblast-restricted expression of Col1a2 in the lungs at both baseline and after acute lung injury, making this Credriver strain ideal for fibroblast-specific gene targeting in the study of lung fibrosis. 14,15 To delete Il11ra1 from fibroblasts, 6 to 8 week old Col1a2-CreERT,Il11ra1 loxP/loxP mice received intraperitoneal injections of tamoxifen (50 mg kg −1 body weight) per day for five consecutive days before bleomycin challenge, followed by subsequent tamoxifen injections at day 7, 11, 14, and 17 after bleomycin challenge to delete Il11ra1 from fibroblast populations (CKO mice). Littermate animals were injected with corn oil as vehicle controls (Ctrl mice).…”

MicroRNA-144-3p targets relaxin/insulin-like family peptide receptor 1 (RXFP1) expression in lung fibroblasts from patients with idiopathic pulmonary fibrosis

“…9, E and F). Primary mouse lung fibroblasts (MLF) were isolated from C57/Bl6 mice and cultured as described (28). MLF were transfected either with mmu-miR-144-3p mimic or a modified mmu-miR-144-3p mimic to enhance base pairing A, transfection of donor lung fibroblasts with miR-144-3p mimic to decrease RXFP1 levels followed by incubation with low and high concentrations of relaxin.…”

“…Donor human fibroblasts were isolated from lungs miR-144-3p targets RXFP1 expression in IPF that appeared to have no injury by histology but were deemed unacceptable for lung transplant. IPF lung fibroblasts were obtained from patients either at explant or at autopsy (28). Briefly, lung tissue from explanted IPF lungs and age-matched normal donors was collected from the lower lobes to find age and sex of the lines included in the experiments (mean age for IPF 58 years Ϯ 6 and 59 years Ϯ 4 for controls, p ϭ 0.76).…”

TBX2 and TBX3 act downstream of canonical WNT signaling in patterning and differentiation of the mouse ureteric mesenchyme

“…The latter may contribute in some organ settings to fibrosis by depositing collagens (Phillips et al, 2004). A number of reports indicate a more direct involvement of CXCL12 in control of ECM deposition, possibly by conversion of resident fibroblasts to myofibroblasts (Jackson et al, 2017;Rodriguez-Nieves et al, 2016;Tan et al, 2017). Although the role of CXCL12/CXCR4/7 signaling in the ureter has not been analyzed, the above reports suggest that expanded CXCL12 signaling in Tbx2/ 3cDKO ureters contributes in some way to the ectopic deposition of ECM in the inner layer of the UM.…”