scholarly journals PFKFB3-mediated endothelial glycolysis promotes pulmonary hypertension

2019 ◽  
Vol 116 (27) ◽  
pp. 13394-13403 ◽  
Author(s):  
Yapeng Cao ◽  
Xiaoyu Zhang ◽  
Lina Wang ◽  
Qiuhua Yang ◽  
Qian Ma ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Pulmonary Hypertension ◽  
Critical Role ◽  
Causative Role ◽  
Pulmonary Endothelial Cells ◽  
Isolated Lung ◽  
Fructose 2 ◽  
Lung Endothelial Cells ◽  
Proinflammatory Factors

Increased glycolysis in the lung vasculature has been connected to the development of pulmonary hypertension (PH). We therefore investigated whether glycolytic regulator 6-phosphofructo-2-kinase/fructose-2, 6-bisphosphatase (PFKFB3)-mediated endothelial glycolysis plays a critical role in the development of PH. Heterozygous global deficiency of Pfkfb3 protected mice from developing hypoxia-induced PH, and administration of the PFKFB3 inhibitor 3PO almost completely prevented PH in rats treated with Sugen 5416/hypoxia, indicating a causative role of PFKFB3 in the development of PH. Immunostaining of lung sections and Western blot with isolated lung endothelial cells showed a dramatic increase in PFKFB3 expression and activity in pulmonary endothelial cells of rodents and humans with PH. We generated mice that were constitutively or inducibly deficient in endothelial Pfkfb3 and found that these mice were incapable of developing PH or showed slowed PH progression. Compared with control mice, endothelial Pfkfb3-knockout mice exhibited less severity of vascular smooth muscle cell proliferation, endothelial inflammation, and leukocyte recruitment in the lungs. In the absence of PFKFB3, lung endothelial cells from rodents and humans with PH produced lower levels of growth factors (such as PDGFB and FGF2) and proinflammatory factors (such as CXCL12 and IL1β). This is mechanistically linked to decreased levels of HIF2A in lung ECs following PFKFB3 knockdown. Taken together, these results suggest that targeting PFKFB3 is a promising strategy for the treatment of PH.

scholarly journals Glycolysis links reciprocal activation of myeloid cells and endothelial cells in the retinal angiogenic niche

2020 ◽  
Vol 12 (555) ◽  
pp. eaay1371 ◽  
Author(s):  
Zhiping Liu ◽  
Jiean Xu ◽  
Qian Ma ◽  
Xiaoyu Zhang ◽  
Qiuhua Yang ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Critical Role ◽  
Myeloid Cells ◽  
Cell Types ◽  
Acetyl Coenzyme A ◽  
Enhanced Production ◽  
Fructose 2 ◽  
Retinal Angiogenesis ◽  
Cellular Components

The coordination of metabolic signals among different cellular components in pathological retinal angiogenesis is poorly understood. Here, we showed that in the pathological angiogenic vascular niche, retinal myeloid cells, particularly macrophages/microglia that are spatially adjacent to endothelial cells (ECs), are highly glycolytic. We refer to these macrophages/microglia that exhibit a unique angiogenic phenotype with increased expression of both M1 and M2 markers and enhanced production of both proinflammatory and proangiogenic cytokines as pathological retinal angiogenesis–associated glycolytic macrophages/microglia (PRAGMs). The phenotype of PRAGMs was recapitulated in bone marrow–derived macrophages or retinal microglia stimulated by lactate that was produced by hypoxic retinal ECs. Knockout of 6-phosphofructo-2-kinase/fructose-2, 6-bisphosphatase (PFKFB3; Pfkfb3 for rodents), a glycolytic activator in myeloid cells, impaired the ability of macrophages/microglia to acquire an angiogenic phenotype, rendering them unable to promote EC proliferation and sprouting and pathological neovascularization in a mouse model of oxygen-induced proliferative retinopathy. Mechanistically, hyperglycolytic macrophages/microglia produced large amount of acetyl–coenzyme A, leading to histone acetylation and PRAGM-related gene induction, thus reprogramming macrophages/microglia into an angiogenic phenotype. These findings reveal a critical role of glycolytic metabolites as initiators of reciprocal activation of macrophages/microglia and ECs in the retinal angiogenic niche and suggest that strategies targeting the metabolic communication between these cell types may be efficacious in the treatment of pathological retinal angiogenesis.

scholarly journals Critical Role of Caveolin-1 Loss/Dysfunction in Pulmonary Hypertension

2021 ◽  
Vol 9 (4) ◽  
pp. 58
Author(s):  
Rajamma Mathew
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cells ◽  
Pulmonary Hypertension ◽  
Membrane Protein ◽  
Critical Role ◽  
High Morbidity ◽  
Caveolin 1 ◽  
Enhanced Expression ◽  
Medial Hypertrophy

Pulmonary hypertension (PH) is a rare disease with a high morbidity and mortality rate. A number of systemic diseases and genetic mutations are known to lead to PH. The main features of PH are altered vascular relaxation responses and the activation of proliferative and anti-apoptotic pathways, resulting in pulmonary vascular remodeling, elevated pulmonary artery pressure, and right ventricular hypertrophy, ultimately leading to right heart failure and premature death. Important advances have been made in the field of pulmonary pathobiology, and several deregulated signaling pathways have been shown to be associated with PH. Clinical and experimental studies suggest that, irrespective of the underlying disease, endothelial cell disruption and/or dysfunction play a key role in the pathogenesis of PH. Endothelial caveolin-1, a cell membrane protein, interacts with and regulates several transcription factors and maintains homeostasis. Disruption of endothelial cells leads to the loss or dysfunction of endothelial caveolin-1, resulting in reciprocal activation of proliferative and inflammatory pathways, leading to cell proliferation, medial hypertrophy, and PH, which initiates PH and facilitates its progression. The disruption of endothelial cells, accompanied by the loss of endothelial caveolin-1, is accompanied by enhanced expression of caveolin-1 in smooth muscle cells (SMCs) that leads to pro-proliferative and pro-migratory responses, subsequently leading to neointima formation. The neointimal cells have low caveolin-1 and normal eNOS expression that may be responsible for promoting nitrosative and oxidative stress, furthering cell proliferation and metabolic alterations. These changes have been observed in human PH lungs and in experimental models of PH. In hypoxia-induced PH, there is no endothelial disruption, loss of endothelial caveolin-1, or enhanced expression of caveolin-1 in SMCs. Hypoxia induces alterations in membrane composition without caveolin-1 or any other membrane protein loss. However, caveolin-1 is dysfunctional, resulting in cell proliferation, medial hypertrophy, and PH. These alterations are reversible upon removal of hypoxia, provided there is no associated EC disruption. This review examined the role of caveolin-1 disruption and dysfunction in PH.

Persistent Pulmonary Hypertension of the Newborn: Role of Nitric Oxide

1995 ◽  
Vol 10 (6) ◽  
pp. 270-282
Author(s):  
Stella Kourembanas
Keyword(s):  
Nitric Oxide ◽  
Pulmonary Hypertension ◽  
Structural Changes ◽  
Critical Role ◽  
Persistent Pulmonary Hypertension ◽  
Cell Contractility ◽  
Vasoactive Mediators ◽  
Nitric Oxide Therapy

Persistent pulmonary hypertension of the newborn (PPHN) is a common cause of respiratory failure in the full-term neonate. Molecular and cellular studies in vascular biology have revealed that endothelial-derived mediators play a critical role in the pathogenesis and treatment of PPHN. Endothelial-derived vasoconstrictors, like endothelin, may increase smooth muscle cell contractility and growth, leading to the physiologic and structural changes observed in the pulmonary arterioles of infants with this disease. On the other hand, decreased production of the endothelial-derived relaxing factor, nitric oxide, may exacerbate pulmonary vasoreactivity and lead to more severe pulmonary hypertension. Exogenous (inhaled) nitric oxide therapy reduces pulmonary vascular resistance and improves oxygenation. The safety and efficacy of this therapy in reducing the need for extracorporeal membrane oxygenation and decreasing long-term morbidity is being tested in several trials nationally and abroad. Understanding the basic mechanisms that regulate the gene expression and production of these vasoactive mediators will lead to improved preventive and therapeutic strategies for PPHN.

scholarly journals Integrated Single Cell Atlas of Endothelial Cells of the Human Lung

Circulation ◽  
2021 ◽  
Author(s):  
Jonas C. Schupp ◽  
Taylor S. Adams ◽  
Carlos Cosme Jr. ◽  
Micha Sam Brickman Raredon ◽  
Yifan Yuan ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Pulmonary Hypertension ◽  
Single Cell ◽  
Differential Expression ◽  
Human Lung ◽  
Differential Expression Analysis ◽  
Cell Types ◽  
Marker Genes ◽  
Lung Endothelium ◽  
Lung Endothelial Cells

Background: The cellular diversity of the lung endothelium has not been systematically characterized in humans. Here, we provide a reference atlas of human lung endothelial cells (ECs) to facilitate a better understanding of the phenotypic diversity and composition of cells comprising the lung endothelium. Methods: We reprocessed human control single cell RNA sequencing (scRNAseq) data from six datasets. EC populations were characterized through iterative clustering with subsequent differential expression analysis. Marker genes were validated by fluorescent microscopy and in situ hybridization. scRNAseq of primary lung ECs cultured in-vitro was performed. The signaling network between different lung cell types was studied. For cross species analysis or disease relevance, we applied the same methods to scRNAseq data obtained from mouse lungs or from human lungs with pulmonary hypertension. Results: Six lung scRNAseq datasets were reanalyzed and annotated to identify over 15,000 vascular EC cells from 73 individuals. Differential expression analysis of EC revealed signatures corresponding to endothelial lineage, including pan-endothelial, pan-vascular and subpopulation-specific marker gene sets. Beyond the broad cellular categories of lymphatic, capillary, arterial and venous ECs, we found previously indistinguishable subpopulations: among venous EC, we identified two previously indistinguishable populations, pulmonary-venous ECs (COL15A1neg) localized to the lung parenchyma and systemic-venous ECs (COL15A1pos) localized to the airways and the visceral pleura; among capillary EC, we confirmed their subclassification into recently discovered aerocytes characterized by EDNRB, SOSTDC1 and TBX2 and general capillary EC. We confirmed that all six endothelial cell types, including the systemic-venous EC and aerocytes, are present in mice and identified endothelial marker genes conserved in humans and mice. Ligand-receptor connectome analysis revealed important homeostatic crosstalk of EC with other lung resident cell types. scRNAseq of commercially available primary lung ECs demonstrated a loss of their native lung phenotype in culture. scRNAseq revealed that the endothelial diversity is maintained in pulmonary hypertension. Our manuscript is accompanied by an online data mining tool (www.LungEndothelialCellAtlas.com). Conclusions: Our integrated analysis provides the comprehensive and well-crafted reference atlas of lung endothelial cells in the normal lung and confirms and describes in detail previously unrecognized endothelial populations across a large number of humans and mice.

scholarly journals Metformin-stimulated AMPK-α1 promotes microvascular repair in acute lung injury

2013 ◽  
Vol 305 (11) ◽  
pp. L844-L855 ◽  
Author(s):  
Ming-Yuan Jian ◽  
Mikhail F. Alexeyev ◽  
Paul E. Wolkowicz ◽  
Jaroslaw W. Zmijewski ◽  
Judy R. Creighton
Keyword(s):  
Endothelial Cells ◽  
Acute Lung Injury ◽  
Lung Injury ◽  
Ex Vivo ◽  
Endothelial Permeability ◽  
Beneficial Effects ◽  
Isolated Lung

Acute lung injury secondary to sepsis is a leading cause of mortality in sepsis-related death. Present therapies are not effective in reversing endothelial cell dysfunction, which plays a key role in increased vascular permeability and compromised lung function. AMP-activated protein kinase (AMPK) is a molecular sensor important for detection and mediation of cellular adaptations to vascular disruptive stimuli. In this study, we sought to determine the role of AMPK in resolving increased endothelial permeability in the sepsis-injured lung. AMPK function was determined in vivo using a rat model of endotoxin-induced lung injury, ex vivo using the isolated lung, and in vitro using cultured rat pulmonary microvascular endothelial cells (PMVECs). AMPK stimulation using N1-(α-d-ribofuranosyl)-5-aminoimidizole-4-carboxamide or metformin decreased the LPS-induced increase in permeability, as determined by filtration coefficient ( Kf) measurements, and resolved edema as indicated by decreased wet-to-dry ratios. The role of AMPK in the endothelial response to LPS was determined by shRNA designed to decrease expression of the AMPK-α1 isoform in capillary endothelial cells. Permeability, wounding, and barrier resistance assays using PMVECs identified AMPK-α1 as the molecule responsible for the beneficial effects of AMPK in the lung. Our findings provide novel evidence for AMPK-α1 as a vascular repair mechanism important in the pulmonary response to sepsis and identify a role for metformin treatment in the management of capillary injury.

scholarly journals Shear stress augments mitochondrial ATP generation that triggers ATP release and Ca2+ signaling in vascular endothelial cells

2018 ◽  
Vol 315 (5) ◽  
pp. H1477-H1485 ◽  
Author(s):  
Kimiko Yamamoto ◽  
Hiromi Imamura ◽  
Joji Ando
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Vascular Endothelial Cells ◽  
Critical Role ◽  
Atp Release ◽  
Vascular Endothelial ◽  
The Novel ◽  
Caveolin 1 ◽  
Atp Generation

Vascular endothelial cells (ECs) sense and transduce hemodynamic shear stress into intracellular biochemical signals, and Ca2+ signaling plays a critical role in this mechanotransduction, i.e., ECs release ATP in the caveolae in response to shear stress and, in turn, the released ATP activates P2 purinoceptors, which results in an influx into the cells of extracellular Ca2+. However, the mechanism by which the shear stress evokes ATP release remains unclear. Here, we demonstrated that cellular mitochondria play a critical role in this process. Cultured human pulmonary artery ECs were exposed to controlled levels of shear stress in a flow-loading device, and changes in the mitochondrial ATP levels were examined by real-time imaging using a fluorescence resonance energy transfer-based ATP biosensor. Immediately upon exposure of the cells to flow, mitochondrial ATP levels increased, which was both reversible and dependent on the intensity of shear stress. Inhibitors of the mitochondrial electron transport chain and ATP synthase as well as knockdown of caveolin-1, a major structural protein of the caveolae, abolished the shear stress-induced mitochondrial ATP generation, resulting in the loss of ATP release and influx of Ca2+ into the cells. These results suggest the novel role of mitochondria in transducing shear stress into ATP generation: ATP generation leads to ATP release in the caveolae, triggering purinergic Ca2+ signaling. Thus, exposure of ECs to shear stress seems to activate mitochondrial ATP generation through caveola- or caveolin-1-mediated mechanisms. NEW & NOTEWORTHY The mechanism of how vascular endothelial cells sense shear stress generated by blood flow and transduce it into functional responses remains unclear. Real-time imaging of mitochondrial ATP demonstrated the novel role of endothelial mitochondria as mechanosignaling organelles that are able to transduce shear stress into ATP generation, triggering ATP release and purinoceptor-mediated Ca2+ signaling within the cells.

Abstract TP99: Human Lung Endothelial Cell Anti-Inflammatory and Regenerative Responses in Acute Ischemic Stroke

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Nikunj Satani ◽  
Kaavya Giridhar ◽  
Natalia Wewior ◽  
Dominique D Norris ◽  
Scott D Olson ◽  
...  
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
Inflammatory Responses ◽  
Inflammatory Factors ◽  
Stroke Severity ◽  
Stroke Patients ◽  
Anti Inflammatory ◽  
Lung Endothelial Cells ◽  
Stroke Mimic

Background: Inflammatory responses after stroke consists of central and peripheral immune responses. The role of the spleen after stroke is well-known, however the role of the lungs has not been studied in detail. We explored the relation between stroke severity and immunomodulatory changes in lung endothelial cells. Methods: Human pulmonary endothelial cells (hPECs, Cell Biologics) were cultured at passage 3. Serum from stroke patients with NIH Stroke Scale (NIHSS) severity ranging from 0 to 20 was collected at 24 hours after stroke. hPECs were exposed to media with 1) 10% FBS alone (N=6), 2) 10% serum from stroke patients (N=72), or 3) 10% serum from stroke mimic patients (N=6). After 3 hour of exposure, fresh media was added and secretomes from hPECs were measured after 24 hours. We isolated RNA from hPECs after 3 hour of serum exposure and measured gene expression (N=6 for each group). Secretome and gene changes in hPECs were analyzed based on stroke severity, tPA treatment, and co-morbidities. Results: Serum from stroke patients reduced the secretion of IL-8, MCP-1 and Fractalkine (p<0.01), and increased the secretion of VEGF and BDNF (p<0.01) from hPECs. These effects were more pronounced depending on stroke severity (Fig). There was no effect of tPA or T2DM on hPECs secretomes. There was significantly reduced gene expression of IL-6, IL-8, MCP-1 and IL-1β and significantly higher expression of ICAM1, IGF-1 and TGF-β1 as compared to stroke mimics. Conclusion: Exposure of hPECs to serum from stroke patients alters their immunomodulatory properties. Higher severity of stroke leads to more protective response from hPECs by reducing the secretion of pro-inflammatory factors, while increasing the secretion of anti-inflammatory factors.

P4689How is the impact of updated hemodynamic definitions on frequencies of overall pulmonary hypertension and pre-capillary pulmonary hypertension as compared to those with previous criteria

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
S Tanyeri ◽  
B Keskin ◽  
O Y Akbal ◽  
A Hakgor ◽  
A Karagoz ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Critical Role ◽  
Right Heart ◽  
Right Heart Catheterisation ◽  
Mean Pressure ◽  
Pulmonary Arterial ◽  
European Society Of Cardiology ◽  
The Impact ◽  
Wedge Pressure

Abstract Background and aim In this study we evaluated the impact of the updated pulmonary hypertension (PH) definitive criteria proposed in 6th World PH Symposium (WSPH) on numbers and frequencies of and pre- versus post-capillary PH as compared to those in European Society of Cardiology (ESC) 2015 PH Guidelines. Methods Study group comprised the retrospectively evaluated 1299 patients (pts) (age 53.1±18.8 years, female 807, 62.1%) who underwent right heart catheterisation (RHC) with different indications between 2006 and 2018. For ESC and WSPH PH definitions, pulmonary arterial mean pressure (PAMP) ≥25 mmHg (definition-A) and PAMP >20 mmHg (definition-B) RHC criteria were used, respectively. For pre-capillary PH definitions, pulmonary artery wedge pressure (PAWP) ≤15 mmHg and pulmonary vascular resistance (PVR) ≥3 Wood units criteria were included in the both definitions. Results In RHC assessments, PAMP ≥25 mmHg and >20 mmHg were noted in 891 (68.6%) and 1051 (80.9%) of overall pts, respectively. Moreover, pre-capillary PH was diagnosed in 284 (21.8%) and 298 (22.9%) with definition-A and B, respectively. Although updated WSPH definition was associated with a net 12.3% and a relative 18% increase in the overall PH diagnosis, net and relative changes in the frequency of the pre-capillary PH were only 1% and 4.9%. Increase in the overall PH with updated WSPH criterias compared to previous ESC definitions was associated with increase in the number of pre-capillary PH (n=298, 22.9%) but not in the overall frequency of post-capillary PH (688, 52.9%). Because PVR was the product of the transpulmonary gradient (PAMP minus PAWP) divided by cardiac output, this measure was found to keep specificity for distinction between pre- versus post-capillary PH even after lowering thetreshold diagnostic for PAMP from 25 to 20 mmHg. Conclusions Although updated WSPH definition was associated with net 12.3% and relative 18% increase in the overall PH diagnosis, its impact on frequencies of pre- versus post-capillary PH within overall PH population was negligible.These seem to be due to critical role of PVR ensuring specificity in pre-capillary PH diagnosis even after lowering the definitive PAMP treshold to 20 mmHg.

Pulmonary reduction of an intravascular redox polymer

2001 ◽  
Vol 280 (6) ◽  
pp. L1290-L1299 ◽  
Author(s):  
Said H. Audi ◽  
Robert D. Bongard ◽  
Yoshiyuki Okamoto ◽  
Marilyn P. Merker ◽  
David L. Roerig ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Superoxide Dismutase ◽  
Electron Transport ◽  
Kinetic Model ◽  
Electron Acceptors ◽  
Redox Polymer ◽  
Pulmonary Endothelial Cells ◽  
Equilibrium Level ◽  
A Cell

Pulmonary endothelial cells in culture reduce external electron acceptors via transplasma membrane electron transport (TPMET). In studying endothelial TPMET in intact lungs, it is difficult to exclude intracellular reduction and reducing agents released by the lung. Therefore, we evaluated the role of endothelial TPMET in the reduction of a cell-impermeant redox polymer, toluidine blue O polyacrylamide (TBOP+), in intact rat lungs. When added to the perfusate recirculating through the lungs, the venous effluent TBOP+concentration decreased to an equilibrium level reflecting TBOP+ reduction and autooxidation of its reduced (TBOPH) form. Adding superoxide dismutase (SOD) to the perfusate increased the equilibrium TBOP+ concentration. Kinetic analysis indicated that the SOD effect could be attributed to elimination of the superoxide product of TBOPH autooxidation rather than of superoxide released by the lungs, and experiments with lung-conditioned perfusate excluded release of other TBOP+ reductants in sufficient quantities to cause significant TBOP+ reduction. Thus the results indicate that TBOP+ reduction is via TPMET and support the utility of TBOP+ and the kinetic model for investigating TPMET mechanisms and their adaptations to physiological and pathophysiological stresses in the intact lung.

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