Early activation of the cardiac CX3CL1/CX3CR1 axis delays β-adrenergic-induced heart failure

Abstract

We recently highlighted a novel potential protective paracrine role of cardiac myeloid CD11b/c cells improving resistance of adult hypertrophied cardiomyocytes to oxidative stress and potentially delaying evolution towards heart failure (HF) in response to early β-adrenergic stimulation. Here we characterized macrophages (Mφ) in hearts early infused with isoproterenol as compared to control and failing hearts and evaluated the role of upregulated CX3CL1 in cardiac remodeling. Flow cytometry, immunohistology and Mφ-depletion experiments evidenced a transient increase in Mφ number in isoproterenol-infused hearts, proportional to early concentric hypertrophy (ECH) remodeling and limiting HF. Combining transcriptomic and secretomic approaches we characterized Mφ-enriched CD45+ cells from ECH hearts as CX3CL1- and TNFα-secreting cells. In-vivo experiments, using intramyocardial injection in ECH hearts of either Cx3cl1 or Cx3cr1 siRNA, or Cx3cr1−/− knockout mice, identified the CX3CL1/CX3CR1 axis as a protective pathway delaying transition to HF. In-vitro results showed that CX3CL1 not only enhanced ECH Mφ proliferation and expansion but also supported adult cardiomyocyte hypertrophy via a synergistic action with TNFα. Our data underscore the in-vivo transient protective role of the CX3CL1/CX3CR1 axis in ECH remodeling and suggest the participation of CX3CL1-secreting Mφ and their crosstalk with CX3CR1-expressing cardiomyocytes to delay HF.

Transcriptomic and Lipidomic Mapping of Macrophages in the Hub of Chronic Beta-Adrenergic-Stimulation Unravels Hypertrophy-, Proliferation-, and Lipid Metabolism-Related Genes as Novel Potential Markers of Early Hypertrophy or Heart Failure

“…Mice were implanted with an osmotic micropump (Alzet, Charles River, L’Arbresles, France) containing either Isoproterenol (Iso: 30 mg/kg/day) or vehicle for either 14 or 28 days to develop either ECH or HF, respectively, as previously reported [ 5 , 6 ]. As previously published, there was a variability in the kinetics or in the maximum intensity of cardiac remodeling triggered by Iso.…”

“…Cytometry data were acquired on a BD FACSAria II cell sorter. After gating on CD11b + cells, doublets were excluded and live (PI exclusion) CD14 + /CD64 + macrophages were sorted directly into RLT lysis buffer (Qiagen, Les Ulis, France) or water and kept at −80 °C until RNAseq or lipidomic analysis, respectively, as shown in Supplementary Materials Figure S1 and as previously reported [ 5 ].…”

“…Normalization and differential statistical analysis were performed with the GLM EdgeR package. RNA-Seq data has been made publicly available through the NCBI Gene Expression Omnibus (GEO), GEO accession number GSE157035, as previously reported [ 5 ]. Gene Analyses were performed using Ingenuity Pathway Analysis (IPA) (version 448560M) (Qiagen, les Ulis, France) and Metascape software (developped by Zhou et al [ 10 ]).…”

“…These plastic cells adapt their physiology in response to cardiac and systemic stimuli. It is clearly emerging that beta-AR pathways interplay with macrophages to play a pivotal role on inflammation and immunomodulation shaping the phenotype of tissue remodeling [ 4 , 5 , 6 ]. We recently demonstrated that hearts subjected to chronic beta-AR agonist (isoproterenol (Iso)) stimulation exhibit an early adaptive transient increase in tissue macrophages exerting a CX3CL1/TNFalpha-dependent pro-hypertrophic impact and a protective role against transition to HF [ 5 ].…”

“…It is clearly emerging that beta-AR pathways interplay with macrophages to play a pivotal role on inflammation and immunomodulation shaping the phenotype of tissue remodeling [ 4 , 5 , 6 ]. We recently demonstrated that hearts subjected to chronic beta-AR agonist (isoproterenol (Iso)) stimulation exhibit an early adaptive transient increase in tissue macrophages exerting a CX3CL1/TNFalpha-dependent pro-hypertrophic impact and a protective role against transition to HF [ 5 ]. In addition, another study by our group identified activation of the Orai3-dependent calcium channel in response to TNFalpha secreted by macrophages as a novel pro-hypertrophic stimulus in Iso- and pressure overload models of early cardiac remodeling [ 6 ].…”