Gli1+ mesenchymal stromal cells form a pathological niche to promote airway progenitor metaplasia in the fibrotic lung.
Ontology highlight
ABSTRACT:
SUBMITTER: Cassandras M
PROVIDER: S-EPMC7642162 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:A single-cell transcriptional analysis was performed on GLI1+ stromal cells from the adult murine lung during homeostasis and after fibrotic injury. The goal is to understand the role of GLI1+ stromal cells in lung fibrosis and repair. Whole adult murine lung tissue from two samples were separately dissociated to single cells and subjected to fluorescence activated cell sorting (FACS) to select all live GLI1+ cells. One sample was treated with bleomycin to induce fibrosis and the other was treated with saline as a control. The single cell RNA-sequencing library was generated separately for the bleomycin and saline-treated samples. Cells were sequenced at a depth of ~70,000 reads/cell. We captured approximately 17,700 cells with a median of 2,400 genes detected per cell utilizing a droplet-based barcoding approach to capture single cells for RNA sequencing. After bleomycin-induced fibrosis, we identified a novel "myofibroblast" subset of GLI1 cells that contribute to injury and repair. Injured GLI1 cells also reveal dysregulation in key developmental pathways, including BMP signaling, that contribute to metaplastic repair after fibrotic injury.
2020-08-17 | GSE140032 | GEO
Project description:Microenvironment cues received by haematopoietic stem cells (HSC) are important in regulating the choice between self-renewal and differentiation. On the basis of the differential expression of cell-surface markers, here we identify a mesenchymal stromal progenitor hierarchy, where CD45(-)Ter119(-)CD31(-)CD166(-)CD146(-)Sca1(+)(Sca1(+)) progenitors give rise to CD45(-)Ter119(-)CD31(-)CD166(-)CD146(+)(CD146(+)) intermediate and CD45(-)Ter119(-)CD31(-)CD166(+)CD146(-)(CD166(+)) mature osteo-progenitors. All three progenitors preserve HSC long-term multi-lineage reconstitution capability in vitro; however, their in vivo fates are different. Post-transplantation, CD146(+) and CD166(+) progenitors form bone only. While Sca1(+) progenitors produce CD146(+), CD166(+) progenitors, osteocytes and CXCL12-producing stromal cells. Only Sca1(+) progenitors are capable of homing back to the marrow post-intravenous infusion. Ablation of Sca1(+) progenitors results in a decrease of all three progenitor populations as well as haematopoietic stem/progenitor cells. Moreover, suppressing production of KIT-ligand in Sca1(+) progenitors inhibits their ability to support HSCs. Our results indicate that Sca1(+) progenitors, through the generation of both osteogenic and stromal cells, provide a supportive environment for hematopoiesis.
| S-EPMC5062560 | biostudies-other
Project description:Bone marrow (BM) fibrosis was thought to be induced exclusively by mesenchymal stromal cells (MSCs). However, we and others found that neoplastic fibrocytes induce BM fibrosis in myelofibrosis (MF). Because glioma-associated oncogene-1 (GLI1), an effector of the Hedgehog pathway, plays a role in the induction of BM fibrosis, we wondered whether GLI1 affects fibrocyte-induced BM fibrosis in MF. Multiplexed fluorescence immunohistochemistry analysis of MF patients' BM detected high levels of GLI1 in MF fibrocytes compared to MSCs or normal fibrocytes. Immunostaining, RNA in situ hybridization, gene expression analysis, and western immunoblotting detected high levels of GLI1 and GLI1-induced matrix metalloproteases (MMP) 2 and 9 in MF patients BM-derived cultured fibrocytes. Similarly, MF patients' BM-derived GLI1+ fibrocytes were found in BMs and spleens of MF xenograft mice. GLI1 silencing reduced the levels of MMP2/9, phosphorylated SMAD2/3, and procollagen-I, and knockdown or inhibition of GLI1 decreased fibrocyte formation and induced apoptosis of both fibrocytes and fibrocyte progenitors. Because Janus kinase (JAK)2-induced STAT3 is constitutively activated in MF and because STAT3 induces GLI1 expression, we sought to determine whether STAT3 activates GLI1 in MF fibrocytes. Imaging analysis detected phosphotyrosine STAT3 in MF patients' BM fibrocytes, and transfection of fibrocytes with STAT3-siRNA or treatment with a JAK1/2 inhibitor ruxolitinib reduced GLI1 and MMP2/9 levels. Chromatin immunoprecipitation and a luciferase assay revealed that STAT3 induced the expression of the GLI1 gene in both MF BM fibrocytes and fibrocyte progenitors. Together, our data suggest that STAT3-activated GLI1 contributes to the induction of BM fibrosis in MF.
| S-EPMC9122946 | biostudies-literature
Project description:Despite the well-accepted view that chronic inflammation contributes to the pathogenesis of Duchenne muscular dystrophy (DMD), the function and regulation of eosinophils remain an unclear facet of type II innate immunity in dystrophic muscle. We report the observation that group 2 innate lymphoid cells (ILC2s) are present in skeletal muscle and are the principal regulators of muscle eosinophils during muscular dystrophy. Eosinophils were elevated in DMD patients and dystrophic mice along with interleukin (IL)-5, a major eosinophil survival factor that was predominantly expressed by muscle ILC2s. We also find that IL-33 was upregulated in dystrophic muscle and was predominantly produced by fibrogenic/adipogenic progenitors (FAPs). Exogenous IL-33 and IL-2 complex (IL-2c) expanded muscle ILC2s and eosinophils, decreased the cross-sectional area (CSA) of regenerating myofibers, and increased the expression of genes associated with muscle fibrosis. The deletion of ILC2s in dystrophic mice mitigated muscle eosinophilia and impaired the induction of IL-5 and fibrosis-associated genes. Our findings highlight a FAP/ILC2/eosinophil axis that promotes type II innate immunity, which influences the balance between regenerative and fibrotic responses during muscular dystrophy.
| S-EPMC8127948 | biostudies-literature
Project description:Chronic inflammation in the stomach induces metaplasia, the pre-cancerous lesion that precedes inflammation-driven neoplastic transformation. While Hedgehog signaling contributes to the initiation of some cancers, its role in gastric transformation remains poorly defined. We found that Helicobacter-infected C57BL/6 mice develop extensive mucous cell metaplasia at 6 month but not at 2 months post-infection. Gastric metaplasia coincided with the appearance of CD45(+)MHCII(+)CD11b(+)CD11c(+) myeloid cells that were normally not present in the chronic gastritis at 2 months. The myeloid regulatory gene Schlafen-4 was identified in a microarray analysis comparing infected WT versus Gli1 null mice and was expressed in the CD11b(+)CD11c(+) myeloid population. Moreover this same population expressed IL-1? and TNF? pro-inflammatory cytokines. By 6 months, the mucous neck cell metaplasia (SPEM) expressed IL-6, phosphorylated STAT3 and the proliferative marker Ki67. Expression was not observed in Gli1 mutant mice consistent with the requirement of Gli1 to induce this pre-neoplastic phenotype. Ectopic Shh ligand expression alone was not sufficient to induce SPEM, but with Helicobacter infection synergistically increased the histologic severity observed with the inflammation. Therefore Hedgehog signaling is required, but is not sufficient to generate pre-neoplastic changes during chronic gastritis. Gli1-dependent myeloid cell differentiation plays a pivotal role in the appearance of myeloid cell subtypes ostensibly required for SPEM development. Moreover, it suggests that therapies capable of targeting this phenotypic switch might prevent progression to metaplasia, the pre-neoplastic change that develops prior to dysplasia and gastric cancer, which also occurs in other epithelial-derived neoplasias initiated by chronic inflammation.
| S-EPMC3592845 | biostudies-literature
Project description:Stromal interaction molecule 1 (STIM1) is the main protein that, along with Orai1, mediates store-operated Ca2+ entry (SOCE) in skeletal muscle. Abnormal SOCE due to mutations in STIM1 is one of the causes of human skeletal muscle diseases. STIM1-R304Q (a constitutively active form of STIM1) has been found in human patients with skeletal muscle phenotypes such as muscle weakness, myalgia, muscle stiffness, and contracture. However, the pathological mechanism(s) of STIM1-R304Q in skeletal muscle have not been well studied. To examine the pathological mechanism(s) of STIM1-R304Q in skeletal muscle, STIM1-R304Q was expressed in mouse primary skeletal myotubes, and the properties of the skeletal myotubes were examined using single-myotube Ca2+ imaging, transmission electron microscopy (TEM), and biochemical approaches. STIM1-R304Q did not interfere with the terminal differentiation of skeletal myoblasts to myotubes and retained the ability of STIM1 to attenuate dihydropyridine receptor (DHPR) activity. STIM1-R304Q induced hyper-SOCE (that exceeded the SOCE by wild-type STIM1) by affecting both the amplitude and the onset rate of SOCE. Unlike that by wild-type STIM1, hyper-SOCE by STIM1-R304Q contributed to a disturbance in Ca2+ distribution between the cytosol and the sarcoplasmic reticulum (SR) (high Ca2+ in the cytosol and low Ca2+ in the SR). Moreover, the hyper-SOCE and the high cytosolic Ca2+ level induced by STIM1-R304Q involve changes in mitochondrial shape. Therefore, a series of these cellular defects induced by STIM1-R304Q could induce deleterious skeletal muscle phenotypes in human patients carrying STIM1-R304Q.
| S-EPMC8394508 | biostudies-literature
Project description:GLI1+ mesenchymal stromal cells modulate epithelial metaplasia in lung fibrosis
| PRJNA588064 | ENA
Project description:The airways are conduits that transport atmospheric oxygen to the distal alveolus. Normally, airway mucous cells are rare. However, diseases of the airway are often characterized by mucous metaplasia, in which there are dramatic increases in mucous cell numbers. As the Notch pathway is known to regulate cell fate in many contexts, we misexpressed the active intracellular domain of the mouse Notch1 receptor in lung epithelium. Notch misexpression resulted in an increase in mucous cells and a decrease in ciliated cells in the airway. Similarly, mouse embryonic tracheal explants and adult human airway epithelium treated with Notch agonists displayed increased mucous cell numbers and decreased ciliated cell numbers. Notch antagonists had the opposite effect. Notably, Notch antagonists blocked IL13-induced mucous metaplasia. IL13 has a well-established role as an inflammatory mediator of mucous metaplasia and functions through Stat6-mediated gene transcription. We found that Notch ligands, however, are able to cause mucous metaplasia in Stat6-null cultured trachea, thus identifying a novel pathway that stimulates mucous metaplasia. Notch signaling may therefore play an important role in airway disease and, by extension, Notch antagonists may have therapeutic value. Conversely, in the distal lung, Notch misexpression prevented the differentiation of alveolar cell types. Instead, the distal lung formed cysts composed of cells that were devoid of alveolar markers but that expressed some, but not all, markers of proximal airway epithelium. Occasional distal cystic cells appeared to differentiate into normal proximal airway cells, suggesting that ectopic Notch signaling arrests the normal differentiation of distal lung progenitors before they initiate an alveolar program.
| S-EPMC2673763 | biostudies-literature
Project description:White adipose tissue expands through both adipocyte hypertrophy and hyperplasia and it is hypothesized that fibrosis or excess accumulation of extracellular matrix within adipose tissue may limit tissue expansion contributing to metabolic dysfunction. The pathways that control adipose tissue remodeling are only partially understood, however it is likely that adipose tissue stromal and perivascular progenitors participate in fibrotic remodeling and also serve as adipocyte progenitors. The goal of this study was to investigate the role of the secreted extracellular matrix protein aortic carboxypeptidase-like protein (ACLP) on adipose progenitor differentiation in the context of adipose tissue fibrosis. Treatment of 10T1/2 mouse cells with recombinant ACLP suppressed adipogenesis and enhanced myofibroblast differentiation, which was dependent on transforming growth factor-? receptor kinase activity. Mice fed a chronic high fat diet exhibited white adipose tissue fibrosis with elevated ACLP expression and cellular fractionation of these depots revealed that ACLP was co-expressed with collagens primarily in the inflammatory cell depleted stromal-vascular fraction (SVF). SVF cells isolated from mice fed a high fat diet secreted increased amounts of ACLP compared to low fat diet control SVF. These cells also exhibited reduced adipogenic differentiation capacity in vitro. Importantly, differentiation studies in primary human adipose stromal cells revealed that mature adipocytes do not express ACLP and exogenous ACLP administration blunted their differentiation potential while upregulating myofibroblastic markers. Collectively, these studies identify ACLP as a stromal derived mediator of adipose progenitor differentiation that may limit adipocyte expansion during white adipose tissue fibrosis.
| S-EPMC5969754 | biostudies-literature
Project description:The mostly widely used bronchodilators in asthma therapy are ?2-adrenoreceptor (?2AR) agonists, but their chronic use causes paradoxical adverse effects. We have previously determined that ?2AR activation is required for expression of the asthma phenotype in mice, but the cell types involved are unknown. We now demonstrate that ?2AR signaling in the airway epithelium is sufficient to mediate key features of the asthmatic responses to IL-13 in murine models. Our data show that inhibition of ?2AR signaling with an aerosolized antagonist attenuates airway hyperresponsiveness (AHR), eosinophilic inflammation, and mucus-production responses to IL-13, whereas treatment with an aerosolized agonist worsens these phenotypes, suggesting that ?2AR signaling on resident lung cells modulates the asthma phenotype. Labeling with a fluorescent ?2AR ligand shows the receptors are highly expressed in airway epithelium. In ?2AR-/- mice, transgenic expression of ?2ARs only in airway epithelium is sufficient to rescue IL-13-induced AHR, inflammation, and mucus production, and transgenic overexpression in WT mice exacerbates these phenotypes. Knockout of ?-arrestin-2 (?arr-2-/-) attenuates the asthma phenotype as in ?2AR-/- mice. In contrast to eosinophilic inflammation, neutrophilic inflammation was not promoted by ?2AR signaling. Together, these results suggest ?2ARs on airway epithelial cells promote the asthma phenotype and that the proinflammatory pathway downstream of the ?2AR involves ?arr-2. These results identify ?2AR signaling in the airway epithelium as capable of controlling integrated responses to IL-13 and affecting the function of other cell types such as airway smooth muscle cells.
| S-EPMC5664525 | biostudies-literature