scholarly journals Epithelial Wntless (Wls) regulates postnatal alveologenesis

Development ◽  
2021 ◽  
Author(s):  
Yinshan Fang ◽  
Hongxia Shao ◽  
Qi Wu ◽  
Neng Chun Wong ◽  
Natalie Tsong ◽  
...  

Alveologenesis requires the coordinated modulation of the epithelial and mesenchymal compartments to generate mature alveolar saccules for efficient gas exchange. However, the molecular mechanisms underlying the epithelial-mesenchymal interaction during alveologenesis are poorly understood. Here, we report that Wnts produced by epithelial cells are critical for neonatal alveologenesis. Deletion of the Wnt chaperon protein Wntless homolog (Wls) disrupts alveolar formation, resulting in enlarged saccules in Sftpc-Cre/Nkx2.1-Cre; Wlsloxp/loxp mutants. Although commitment of the alveolar epithelium is unaffected, α-SMA+ mesenchymal cells persist in the alveoli accompanied by increased collagen deposition and mutants exhibit exacerbated fibrosis following bleomycin challenge. Notably, α-SMA+ cells include a significant number of endothelial cells resembling endothelial to mesenchymal transition (EndMT) which is also present in Ager-CreER; Wlsloxp/loxp mutants following early postnatal Wls deletion. These findings provide initial evidence that epithelial-derived Wnts are critical for the differentiation of the surrounding mesenchyme during early postnatal alveologenesis.

2019 ◽  
Vol 20 (3) ◽  
pp. 458 ◽  
Author(s):  
Fernanda Ursoli Ferreira ◽  
Lucas Eduardo Botelho Souza ◽  
Carolina Hassibe Thomé ◽  
Mariana Tomazini Pinto ◽  
Clarice Origassa ◽  
...  

The endothelial-to-mesenchymal transition (EndMT) is a biological process where endothelial cells (ECs) acquire a fibroblastic phenotype after concomitant loss of the apical-basal polarity and intercellular junction proteins. This process is critical to embryonic development and is involved in diseases such as fibrosis and tumor progression. The signaling pathway of the transforming growth factor β (TGF-β) is an important molecular route responsible for EndMT activation. However, it is unclear whether the anatomic location of endothelial cells influences the activation of molecular pathways responsible for EndMT induction. Our study investigated the molecular mechanisms and signaling pathways involved in EndMT induced by TGF-β2 in macrovascular ECs obtained from different sources. For this purpose, we used four types of endothelial cells (coronary artery endothelial cells, CAECs; primary aortic endothelial cells PAECs; human umbilical vein endothelia cells, HUVECs; and human pulmonary artery endothelial cells, HPAECs) and stimulated with 10 ng/mL of TGF-β2. We observed that among the ECs analyzed in this study, PAECs showed the best response to the TGF-β2 treatment, displaying phenotypic changes such as loss of endothelial marker and acquisition of mesenchymal markers, which are consistent with the EndMT activation. Moreover, the PAECs phenotypic transition was probably triggered by the extracellular signal–regulated kinases 1/2 (ERK1/2) signaling pathway activation. Therefore, the anatomical origin of ECs influences their ability to undergo EndMT and the selective inhibition of the ERK pathway may suppress or reverse the progression of diseases caused or aggravated by the involvement EndMT activation.


Author(s):  
João P. Monteiro ◽  
Julie Rodor ◽  
Axelle Caudrillier ◽  
Jessica P Scanlon ◽  
Ana-Mishel Spiroski ◽  
...  

Rationale: Endothelial-to-mesenchymal transition (EndMT) is a dynamic biological process involved in pathological vascular remodelling. However, the molecular mechanisms that govern this transition remain largely unknown, including the contribution of long non-coding RNAs (lncRNAs). Objective: To investigate the role of lncRNAs in EndMT and their relevance to vascular remodelling. Methods and Results: To study EndMT in vitro, primary endothelial cells (EC) were treated with transforming growth factor-β2 and interleukin-1β. Single-cell and bulk RNA-sequencing were performed to investigate the transcriptional architecture of EndMT and identify regulated lncRNAs. The functional contribution of seven lncRNAs during EndMT was investigated based on a DsiRNA screening assay. The loss of lncRNA MIR503HG was identified as a common signature across multiple human EC types undergoing EndMT in vitro. MIR503HG depletion induced a spontaneous EndMT phenotype, while its overexpression repressed hallmark EndMT changes, regulating 29% of its transcriptome signature. Importantly, the phenotypic changes induced by MIR503HG were independent of miR-424 and miR-503, which overlap the lncRNA locus. The pathological relevance of MIR503HG down-regulation was confirmed in vivo using Sugen/Hypoxia (SuHx)-induced pulmonary hypertension (PH) in mouse, as well as in human clinical samples, in lung sections and blood outgrowth endothelial cells (BOECs) from pulmonary arterial hypertension (PAH) patients. Overexpression of human MIR503HG in SuHx mice led to reduced mesenchymal marker expression, suggesting MIR503HG therapeutic potential. We also revealed that MIR503HG interacts with the Polypyrimidine Tract Binding Protein 1 (PTB1) and regulates its protein level. PTBP1 regulation of EndMT markers suggests that the role of MIR503HG in EndMT might be mediated in part by PTBP1. Conclusions: This study reports a novel lncRNA transcriptional profile associated with EndMT and reveals the crucial role of the loss of MIR503HG in EndMT and its relevance to pulmonary hypertension.


Life ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 610
Author(s):  
Eloisa Romano ◽  
Irene Rosa ◽  
Bianca Saveria Fioretto ◽  
Marco Matucci-Cerinic ◽  
Mirko Manetti

In systemic sclerosis (SSc), abnormalities in microvessel morphology occur early and evolve into a distinctive vasculopathy that relentlessly advances in parallel with the development of tissue fibrosis orchestrated by myofibroblasts in nearly all affected organs. Our knowledge of the cellular and molecular mechanisms underlying such a unique relationship between SSc-related vasculopathy and fibrosis has profoundly changed over the last few years. Indeed, increasing evidence has suggested that endothelial-to-mesenchymal transition (EndoMT), a process in which profibrotic myofibroblasts originate from endothelial cells, may take center stage in SSc pathogenesis. While in arterioles and small arteries EndoMT may lead to the accumulation of myofibroblasts within the vessel wall and development of fibroproliferative vascular lesions, in capillary vessels it may instead result in vascular destruction and formation of myofibroblasts that migrate into the perivascular space with consequent tissue fibrosis and microvessel rarefaction, which are hallmarks of SSc. Besides endothelial cells, other vascular wall-resident cells, such as pericytes and vascular smooth muscle cells, may acquire a myofibroblast-like synthetic phenotype contributing to both SSc-related vascular dysfunction and fibrosis. A deeper understanding of the mechanisms underlying the differentiation of myofibroblasts inside the vessel wall provides the rationale for novel targeted therapeutic strategies for the treatment of SSc.


2018 ◽  
Vol 314 (1) ◽  
pp. L118-L126 ◽  
Author(s):  
Toshio Suzuki ◽  
Erica J. Carrier ◽  
Megha H. Talati ◽  
Anandharajan Rathinasabapathy ◽  
Xinping Chen ◽  
...  

Endothelial-to-mesenchymal transition (EndMT) is a process in which endothelial cells lose polarity and cell-to cell contacts, and undergo a dramatic remodeling of the cytoskeleton. It has been implicated in initiation and progression of pulmonary arterial hypertension (PAH). However, the characteristics of cells which have undergone EndMT cells in vivo have not been reported and so remain unclear. To study this, sugen5416 and hypoxia (SuHx)-induced PAH was established in Cdh5-Cre/Gt(ROSA)26Sortm4(ACTB-tdTomato,EGFP)Luo/J double transgenic mice, in which GFP was stably expressed in pan-endothelial cells. After 3 wk of SuHx, flow cytometry and immunohistochemistry demonstrated CD144-negative and GFP-positive cells (complete EndMT cells) possessed higher proliferative and migratory activity compared with other mesenchymal cells. While CD144-positive and α-smooth muscle actin (α-SMA)-positive cells (partial EndMT cells) continued to express endothelial progenitor cell markers, complete EndMT cells were Sca-1-rich mesenchymal cells with high proliferative and migratory ability. When transferred in fibronectin-coated chamber slides containing smooth muscle media, α-SMA robustly expressed in these cells compared with cEndMT cells that were grown in maintenance media. Demonstrating additional paracrine effects, conditioned medium from isolated complete EndMT cells induced enhanced mesenchymal proliferation and migration and increased angiogenesis compared with conditioned medium from resident mesenchymal cells. Overall, these findings show that EndMT cells could contribute to the pathogenesis of PAH both directly, by transformation into smooth muscle-like cells with higher proliferative and migratory potency, and indirectly, through paracrine effects on vascular intimal and medial proliferation.


2021 ◽  
Author(s):  
Xuechao Jiang ◽  
Tingting Li ◽  
Bojian Li ◽  
Wei Wei ◽  
Fen Li ◽  
...  

The endothelial-to-mesenchymal transition (EndMT) is a critical process that occurs during the development of the outflow tract (OFT). Malformations of the OFT can lead to the occurrence of conotruncal defects (CTD). SOX7 duplication has been reported in patients with congenital CTD, but its specific role in OFT development remains poorly understood. To decipher this, histological analysis showed that SOX7 was regionally expressed in the endocardial endothelial cells and in the mesenchymal cells of the OFT, where EndMT occurs. Experiments, using invitro collagen gel culture system, revealed that SOX7 was a negative regulator of EndMT that inhibited endocardial cell migration and resulted in decreased number of mesenchymal cells. Forced expression of SOX7 in endothelial cells blocked further migration and improved the expression of the adhesion protein vascular endothelial (VE)-cadherin. Moreover, a VE-cadherin knockdown could partly reverse the SOX7-mediated repression of cell migration. Luciferase and electrophoretic mobility shift assays demonstrated that SOX7 up-regulated VE-cadherin by directly binding to the gene’s promoter in endothelial cells. The coding exons and splicing regions of the SOX7 gene were also scanned in the 536 sporadic CTD patients and in 300 unaffected controls, which revealed four heterozygous SOX7 mutations. Luciferase assays revealed that two SOX7 variants weakened the transactivation of the VE-cadherin promoter. In conclusion, SOX7 inhibited EndMT during OFT development by directly upregulating the endothelial-specific adhesion molecule VE-cadherin. SOX7 mutations can lead to impaired EndMT by regulating VE-cadherin, which may give rise to the molecular mechanisms associated with SOX7 in CTD pathogenesis.


2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
S Rittig ◽  
L Gaal ◽  
K Kokot ◽  
S Gaul ◽  
J Okun ◽  
...  

Abstract Background and purpose Trimethylamine N-oxide (TMAO) is associated with a higher risk of atherosclerotic diseases. However, the underlying molecular mechanisms are not completely understood. Inflammation and following endothelial-to-mesenchymal transition (EndMT) – a process where endothelial cells (ECs) lose their function and phenotype and gain a mesenchymal character – contribute to the development of atherosclerosis. We therefore aimed to investigate the potential uptake of TMAO into ECs and its potential impact on inflammation and subsequent EndMT. Methods and results Tandem mass spectrometry revealed a time-dependent uptake of TMAO into primary human endothelial cells of 0.5 nmol/mg protein within the first 30 minutes and of 5.8 nmol/mg within 24 hours. The uptake of TMAO resulted in a significant increase of inflammation as measured by E-selectin expression (+63.8-fold). A prolonged treatment with TMAO for 3 days resulted in an increase of EndMT indicated by a significant increase of the mesenchymal marker genes Versican (+6.8-fold) and Calponin (+11.9-fold), as well as a concomitant decrease of the endothelial marker LYVE1 (−92%). For identification of a potential TMAO transporter in human endothelial cells, we screened for the expression of Solute Carrier Family member transporters in ECs. Through our research, overexpression of the carrier A5 in ECs resulted in a 36% higher intracellular TMAO concentration as early as 30 minutes. In turn, causing a knockdown of A5 prevented TMAO induced inflammation (−77.8% induction of E-Selectin) and EndMT (−98,3% induction of Versican and −461% induction of Calponin). Conclusion Using a large screening approach, we identified A5 as the first TMAO transporter described in ECs. TMAO uptake results in increased inflammation of ECs and induction of EndMT. The data identify a novel mechanism of TMAO uptake into human ECs that may help to better understand lifestyle-mediated effects on atherosclerosis. FUNDunding Acknowledgement Type of funding sources: None.


Author(s):  
Jennifer S. Fang ◽  
Nan W. Hultgren ◽  
Christopher C. W. Hughes

During development and in several diseases, endothelial cells (EC) can undergo complete endothelial-to-mesenchymal transition (EndoMT or EndMT) to generate endothelial-derived mesenchymal cells. Emerging evidence suggests that ECs can also undergo a partial EndoMT to generate cells with intermediate endothelial- and mesenchymal-character. This partial EndoMT event is transient, reversible, and supports both developmental and pathological angiogenesis. Here, we discuss possible regulatory mechanisms that may control the EndoMT program to dictate whether cells undergo complete or partial mesenchymal transition, and we further consider how these pathways might be targeted therapeutically in cancer.


2020 ◽  
Vol 13 (635) ◽  
pp. eaaz2597 ◽  
Author(s):  
Sara Lovisa ◽  
Eliot Fletcher-Sananikone ◽  
Hikaru Sugimoto ◽  
Janine Hensel ◽  
Sharmistha Lahiri ◽  
...  

Endothelial-to-mesenchymal transition (EndMT) is a cellular transdifferentiation program in which endothelial cells partially lose their endothelial identity and acquire mesenchymal-like features. Renal capillary endothelial cells can undergo EndMT in association with persistent damage of the renal parenchyma. The functional consequence(s) of EndMT in kidney fibrosis remains unexplored. Here, we studied the effect of Twist or Snail deficiency in endothelial cells on EndMT in kidney fibrosis. Conditional deletion of Twist1 (which encodes Twist) or Snai1 (which encodes Snail) in VE-cadherin+ or Tie1+ endothelial cells inhibited the emergence of EndMT and improved kidney fibrosis in two different kidney injury/fibrosis mouse models. Suppression of EndMT limited peritubular vascular leakage, reduced tissue hypoxia, and preserved tubular epithelial health and function. Hypoxia, which was exacerbated by EndMT, resulted in increased Myc abundance in tubular epithelial cells, enhanced glycolysis, and suppression of fatty acid oxidation. Pharmacological suppression or epithelial-specific genetic ablation of Myc in tubular epithelial cells ameliorated fibrosis and restored renal parenchymal function and metabolic homeostasis. Together, these findings demonstrate a functional role for EndMT in the response to kidney capillary endothelial injury and highlight the contribution of endothelial-epithelial cross-talk in the development of kidney fibrosis with a potential for therapeutic intervention.


Author(s):  
Zahra Alvandi ◽  
Joyce Bischoff

Endothelial-to-mesenchymal transition is a dynamic process in which endothelial cells suppress constituent endothelial properties and take on mesenchymal cell behaviors. To begin the process, endothelial cells loosen their cell-cell junctions, degrade the basement membrane, and migrate out into the perivascular surroundings. These initial endothelial behaviors reflect a transient modulation of cellular phenotype, that is, a phenotypic modulation, that is sometimes referred to as partial endothelial-to-mesenchymal transition. Loosening of endothelial junctions and migration are also seen in inflammatory and angiogenic settings such that endothelial cells initiating endothelial-to-mesenchymal transition have overlapping behaviors and gene expression with endothelial cells responding to inflammatory signals or sprouting to form new blood vessels. Reduced endothelial junctions increase permeability, which facilitates leukocyte trafficking, whereas endothelial migration precedes angiogenic sprouting and neovascularization; both endothelial barriers and quiescence are restored as inflammatory and angiogenic stimuli subside. Complete endothelial-to-mesenchymal transition proceeds beyond phenotypic modulation such that mesenchymal characteristics become prominent and endothelial functions diminish. In proadaptive, regenerative settings the new mesenchymal cells produce extracellular matrix and contribute to tissue integrity whereas in maladaptive, pathologic settings the new mesenchymal cells become fibrotic, overproducing matrix to cause tissue stiffness, which eventually impacts function. Here we will review what is known about how TGF (transforming growth factor) β influences this continuum from junctional loosening to cellular migration and its relevance to cardiovascular diseases.


2016 ◽  
Vol 310 (11) ◽  
pp. L1185-L1198 ◽  
Author(s):  
Toshio Suzuki ◽  
Yuji Tada ◽  
Rintaro Nishimura ◽  
Takeshi Kawasaki ◽  
Ayumi Sekine ◽  
...  

Pulmonary vascular endothelial function may be impaired by oxidative stress in endotoxemia-derived acute lung injury. Growing evidence suggests that endothelial-to-mesenchymal transition (EndMT) could play a pivotal role in various respiratory diseases; however, it remains unclear whether EndMT participates in the injury/repair process of septic acute lung injury. Here, we analyzed lipopolysaccharide (LPS)-treated mice whose total number of pulmonary vascular endothelial cells (PVECs) transiently decreased after production of reactive oxygen species (ROS), while the population of EndMT-PVECs significantly increased. NAD(P)H oxidase inhibition suppressed EndMT of PVECs. Most EndMT-PVECs derived from tissue-resident cells, not from bone marrow, as assessed by mice with chimeric bone marrow. Bromodeoxyuridine-incorporation assays revealed higher proliferation of capillary EndMT-PVECs. In addition, EndMT-PVECs strongly expressed c- kit and CD133. LPS loading to human lung microvascular endothelial cells (HMVEC-Ls) induced reversible EndMT, as evidenced by phenotypic recovery observed after removal of LPS. LPS-induced EndMT-HMVEC-Ls had increased vasculogenic ability, aldehyde dehydrogenase activity, and expression of drug resistance genes, which are also fundamental properties of progenitor cells. Taken together, our results demonstrate that LPS induces EndMT of tissue-resident PVECs during the early phase of acute lung injury, partly mediated by ROS, contributing to increased proliferation of PVECs.


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