Dataset Information

Consequences of fibroblast ablation in adult murine hearts

ABSTRACT: Fibroblasts produce the majority of collagen in the heart and are thought to regulate extracellular matrix (ECM) turnover. However, the in vivo role of fibroblasts in structuring the basal ECM network is poorly understood. To examine the effects of fibroblast loss on the microenvironment in the adult murine heart, we generated mice with reduced fibroblast numbers and evaluated the tissue microenvironment during homeostasis and after injury. We determined that a 60-80% reduction in fibroblasts numbers did not overtly change the fibrillar collagen network but did alter the distribution and abundance of type VI collagen, a microfibrillar collagen that forms an open network with the basement membrane. In fibroblast ablated mice, myocardial infarction did not result in ventricular wall rupture, and heart function was more effectively preserved during angiotensin II/phenylephrine (AngII/PE) induced fibrosis. Analysis of cardiomyocyte contractility demonstrated weaker contractions and slower calcium release and reuptake in uninjured and AngII/PE infused fibroblast ablated animals. Moreover, fibroblast ablated hearts have a similar gene expression prolife to hearts with exercise-induced and physiological hypertrophy after AngII/PE infusion. These results suggest that hearts are resilient to a significant degree of fibroblast loss and that fibroblasts can directly impact cardiomyocyte function. Furthermore, a reduction in fibroblasts may have cardioprotective effects heart after injury suggesting that manipulation of the number of fibroblasts may have therapeutic value.

INSTRUMENT(S): LTQ Orbitrap Velos

ORGANISM(S): Mus Musculus (mouse)

TISSUE(S): Heart

SUBMITTER: Sumit Bhutada

LAB HEAD: Suneel Apte

PROVIDER: PXD021739 | Pride | 2023-03-10

REPOSITORIES: Pride

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Dataset's files

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			Action	DRS
	Adult-FibKO_GuHCl_PreTAILS_1Step.raw	Raw
	Adult-FibKO_GuHCl_PreTAILS_Fr1.raw	Raw
	Adult-FibKO_GuHCl_PreTAILS_Fr2.raw	Raw
	Adult-FibKO_GuHCl_PreTAILS_Fr3.raw	Raw
	Adult-FibKO_GuHCl_PreTAILS_Fr4.raw	Raw

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Publications

Consequences of PDGFRα<sup>+</sup> fibroblast reduction in adult murine hearts.

Kuwabara Jill T JT Hara Akitoshi A Bhutada Sumit S Gojanovich Greg S GS Chen Jasmine J Hokutan Kanani K Shettigar Vikram V Lee Anson Y AY DeAngelo Lydia P LP Heckl Jack R JR Jahansooz Julia R JR Tacdol Dillon K DK Ziolo Mark T MT Apte Suneel S SS Tallquist Michelle D MD

eLife 20220923

Fibroblasts produce the majority of collagen in the heart and are thought to regulate extracellular matrix (ECM) turnover. Although fibrosis accompanies many cardiac pathologies and is generally deleterious, the role of fibroblasts in maintaining the basal ECM network and in fibrosis in vivo is poorly understood. We genetically ablated fibroblasts in mice to evaluate the impact on homeostasis of adult ECM and cardiac function after injury. Fibroblast-ablated mice demonstrated a substantive reduc ...[more]

PMID: 36149056

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Project description:Pericytes have been implicated in regulation of inflammatory, reparative, fibrogenic and angiogenic responses in several different organs and pathologic conditions. Although the adult mammalian heart contains abundant pericytes, their fate and involvement in myocardial disease remains unknown. We used NG2Dsred;PDGFRaEGFP pericyte-fibroblast dual reporter mice and inducible NG2CreER mice to study the fate and phenotypic modulation of pericytes in a model of myocardial infarction. The transcriptomic profile of pericyte-derived fibroblasts was studied using PCR arrays. The transcriptomic profile of NG2 lineage cells (pericytes) was studied in control and infarcted hearts using single cell RNA-sequencing analysis. The role of TGF-b signaling in regulation of pericyte phenotype in vivo was investigated using pericyte-specific Tgfbr2 knockout mice. In vitro, the effects of TGF-b were studied in cultured human placental pericytes.In normal mouse hearts, NG2 and PDGFRa identified distinct non-overlapping populations of pericytes and fibroblasts respectively. Following myocardial infarction, a population of cells expressing both pericyte and fibroblast markers emerged. These cells expressed large amounts of extracellular matrix (ECM) genes. Lineage tracing demonstrated that in the infarcted region, a subpopulation of pericytes underwent fibroblast conversion. Single cell RNA-seq experiments demonstrated expansion and diversification of pericyte-derived cells in the infarct, associated with emergence of subpopulations exhibiting accentuated matrix gene synthesis. In vitro studies and the profile of pericyte-derived fibroblasts identified TGF-b as a potentially causative mediator in fibrogenic activation of infarct pericytes. However, pericyte-specific Tgfbr2 disruption had no significant effects on myofibroblast infiltration and collagen deposition in the infarct. Pericyte-specific TGF-b signaling was involved in vascular maturation, mediating formation of a mural cell coat investing infarct neovessels. These reparative effects of infarct pericytes protected the infarcted heart from dilative remodeling.