Higher organisms rely on a closed cardiovascular circulatory system with blood vessels supplying vital nutrients and oxygen to distant tissues. Not surprisingly, vascular pathologies rank among the ...most life-threatening diseases. At the crux of most of these vascular pathologies are (dysfunctional) endothelial cells (ECs), the cells lining the blood vessel lumen. ECs display the remarkable capability to switch rapidly from a quiescent state to a highly migratory and proliferative state during vessel sprouting. This angiogenic switch has long been considered to be dictated by angiogenic growth factors (eg, vascular endothelial growth factor) and other signals (eg, Notch) alone, but recent findings show that it is also driven by a metabolic switch in ECs. Furthermore, these changes in metabolism may even override signals inducing vessel sprouting. Here, we review how EC metabolism differs between the normal and dysfunctional/diseased vasculature and how it relates to or affects the metabolism of other cell types contributing to the pathology. We focus on the biology of ECs in tumor blood vessel and diabetic ECs in atherosclerosis as examples of the role of endothelial metabolism in key pathological processes. Finally, current as well as unexplored EC metabolism-centric therapeutic avenues are discussed.
Endothelial cell (EC) metabolism has lately emerged as a novel and promising therapeutic target to block vascular dysregulation associated with diseases like cancer and blinding eye disease. ...Glycolysis, fatty acid oxidation (FAO) and, more recently, glutamine/asparagine metabolism emerged as key regulators of EC metabolism, able to impact angiogenesis in health and disease. ECs are highly glycolytic as they require ATP and biomass for vessel sprouting. Notably, a regulator of the glycolytic pathway, 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3, controls vessel sprouting during the angiogenic switch and its inhibition in tumour ECs leads to vessel normalization, thereby reducing metastasis and ameliorating chemotherapy. Moreover, FAO promotes EC proliferation through DNA synthesis, and plays an essential role in lymphangiogenesis via epigenetic regulation of histone acetylation. Pathological angiogenesis was decreased upon blockade of carnitine palmitoyltransferase 1, a regulator of FAO in ECs. More recently, metabolism of glutamine, in conjunction with asparagine, was reported to maintain EC sprouting through TCA anaplerosis, redox homeostasis, mTOR activation and endoplasmic stress control. Inactivation or blockade of glutaminase 1, which hydrolyses glutamine into ammonia and glutamate, impairs angiogenesis in health and disease, while silencing of asparagine synthetase reduces vessel sprouting in vitro. In this review, we summarize recent insights into EC metabolism and discuss therapeutic implications of targeting EC metabolism.
In healthy individuals, the endothelium plays a fundamental role in normal health in the maintenance of vascular homeostasis. Endothelial cell (EC) dysfunction results in the development of several ...pathologies. In diabetes, in particular, sustained hyperglycemia, a characteristic of diabetes, contributes to EC dysfunction and consequently mediates the pathogenesis of diabetes-associated micro- and macrovasculopathies. Hyperglycemia-induced EC dysfunction is triggered by elevated levels of oxidative stress derived from several mechanisms, with the mitochondria as a key source, and is exacerbated by a subsequent hyperglycemia-induced self-perpetuating cycle of oxidative stress and aberrant metabolic memory. Recent reports have highlighted the importance of metabolic pathways in EC and suggested the therapeutic potential of targeting EC metabolism. This review focuses on the current knowledge regarding differences in the metabolism of healthy ECs vs. diabetes-associated dysfunctional ECs, and outlines how EC metabolism may be targeted for therapeutic benefit. (Circ J 2015; 79: 934–941)
Endothelial Cell Metabolism Eelen, Guy; de Zeeuw, Pauline; Treps, Lucas ...
Physiological reviews,
01/2018, Letnik:
98, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Endothelial cells (ECs) are more than inert blood vessel lining material. Instead, they are active players in the formation of new blood vessels (angiogenesis) both in health and (life-threatening) ...diseases. Recently, a new concept arose by which EC metabolism drives angiogenesis in parallel to well-established angiogenic growth factors (e.g., vascular endothelial growth factor). 6-Phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3-driven glycolysis generates energy to sustain competitive behavior of the ECs at the tip of a growing vessel sprout, whereas carnitine palmitoyltransferase 1a-controlled fatty acid oxidation regulates nucleotide synthesis and proliferation of ECs in the stalk of the sprout. To maintain vascular homeostasis, ECs rely on an intricate metabolic wiring characterized by intracellular compartmentalization, use metabolites for epigenetic regulation of EC subtype differentiation, crosstalk through metabolite release with other cell types, and exhibit EC subtype-specific metabolic traits. Importantly, maladaptation of EC metabolism contributes to vascular disorders, through EC dysfunction or excess angiogenesis, and presents new opportunities for anti-angiogenic strategies. Here we provide a comprehensive overview of established as well as newly uncovered aspects of EC metabolism.
The maintenance of key germline derived DNA methylation patterns during preimplantation development depends on stores of DNA cytosine methyltransferase-1o (DNMT1o) provided by the oocyte. ...Dnmt1o(mat-/-) mouse embryos born to Dnmt1(Δ1o/Δ1o) female mice lack DNMT1o protein and have disrupted genomic imprinting and associated phenotypic abnormalities. Here, we describe additional female-specific morphological abnormalities and DNA hypomethylation defects outside imprinted loci, restricted to extraembryonic tissue. Compared to male offspring, the placentae of female offspring of Dnmt1(Δ1o/Δ1o) mothers displayed a higher incidence of genic and intergenic hypomethylation and more frequent and extreme placental dysmorphology. The majority of the affected loci were concentrated on the X chromosome and associated with aberrant biallelic expression, indicating that imprinted X-inactivation was perturbed. Hypomethylation of a key regulatory region of Xite within the X-inactivation center was present in female blastocysts shortly after the absence of methylation maintenance by DNMT1o at the 8-cell stage. The female preponderance of placental DNA hypomethylation associated with maternal DNMT1o deficiency provides evidence of additional roles beyond the maintenance of genomic imprints for DNA methylation events in the preimplantation embryo, including a role in imprinted X chromosome inactivation.
Lymphatic vessels (LVs), lined by lymphatic endothelial cells (LECs), are indispensable for life
. However, the role of metabolism in LECs has been incompletely elucidated. In the present study, it ...is reported that LEC-specific loss of OXCT1, a key enzyme of ketone body oxidation
, reduces LEC proliferation, migration and vessel sprouting in vitro and impairs lymphangiogenesis in development and disease in Prox1
mice. Mechanistically, OXCT1 silencing lowers acetyl-CoA levels, tricarboxylic acid cycle metabolite pools, and nucleotide precursor and deoxynucleotide triphosphate levels required for LEC proliferation. Ketone body supplementation to LECs induces the opposite effects. Notably, elevation of lymph ketone body levels by a high-fat, low-carbohydrate ketogenic diet or by administration of the ketone body β-hydroxybutyrate increases lymphangiogenesis after corneal injury and myocardial infarction. Intriguingly, in a mouse model of microsurgical ablation of LVs in the tail, which repeats features of acquired lymphoedema in humans, the ketogenic diet improves LV function and growth, reduces infiltration of anti-lymphangiogenic immune cells and decreases oedema, suggesting a novel dietary therapeutic opportunity.
Endothelial cells (ECs) are highly glycolytic, but whether they generate glycolytic intermediates via gluconeogenesis (GNG) in glucose-deprived conditions remains unknown. Here, we report that ...glucose-deprived ECs upregulate the GNG enzyme PCK2 and rely on a PCK2-dependent truncated GNG, whereby lactate and glutamine are used for the synthesis of lower glycolytic intermediates that enter the serine and glycerophospholipid biosynthesis pathways, which can play key roles in redox homeostasis and phospholipid synthesis, respectively. Unexpectedly, however, even in normal glucose conditions, and independent of its enzymatic activity, PCK2 silencing perturbs proteostasis, beyond its traditional GNG role. Indeed, PCK2-silenced ECs have an impaired unfolded protein response, leading to accumulation of misfolded proteins, which due to defective proteasomes and impaired autophagy, results in the accumulation of protein aggregates in lysosomes and EC demise. Ultimately, loss of PCK2 in ECs impaired vessel sprouting. This study identifies a role for PCK2 in proteostasis beyond GNG.
The heterogeneity of endothelial cells (ECs) across tissues remains incompletely inventoried. We constructed an atlas of >32,000 single-EC transcriptomes from 11 mouse tissues and identified 78 EC ...subclusters, including Aqp7+ intestinal capillaries and angiogenic ECs in healthy tissues. ECs from brain/testis, liver/spleen, small intestine/colon, and skeletal muscle/heart pairwise expressed partially overlapping marker genes. Arterial, venous, and lymphatic ECs shared more markers in more tissues than did heterogeneous capillary ECs. ECs from different vascular beds (arteries, capillaries, veins, lymphatics) exhibited transcriptome similarity across tissues, but the tissue (rather than the vessel) type contributed to the EC heterogeneity. Metabolic transcriptome analysis revealed a similar tissue-grouping phenomenon of ECs and heterogeneous metabolic gene signatures in ECs between tissues and between vascular beds within a single tissue in a tissue-type-dependent pattern. The EC atlas taxonomy enabled identification of EC subclusters in public scRNA-seq datasets and provides a powerful discovery tool and resource value.
•A single-cell EC atlas of healthy murine tissues•This study provides an interactive webtool for comparative analyses and data exploration•Characterization of inter- and intra-tissue EC heterogeneity•Discovery tool for characterization of ECs in other datasets
A comprehensive murine atlas comprising >32,000 single endothelial-cell transcriptomes from 11 mouse tissues is reported, and among the subclusters various classical as well as tissue-specialized endothelial-cell subtypes are defined.
Endothelial cells (ECs) harbor distinct phenotypical and functional characteristics depending on their tissue localization and contribute to brain, eye, lung, and muscle diseases such as dementia, ...macular degeneration, pulmonary hypertension, and sarcopenia. To study their function, isolation of pure ECs in high quantities is crucial. Here, we describe protocols for rapid and reproducible blood vessel EC purification established for scRNA sequencing from murine tissues using mechanical and enzymatic digestion followed by magnetic and fluorescence-activated cell sorting.
For complete details on the use and execution of these protocol, please refer to Kalucka et al. (2020), Rohlenova et al. (2020), and Goveia et al. (2020).
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•Protocols for isolation of murine endothelial cells designed for scRNA-seq•Rapid and efficient isolation of ECs from brain, choroid, lung, and muscle•Combination of magnetic and fluorescent activated cell sorting•High purity and quality of isolated murine endothelial cells evident from scRNA-seq
Endothelial cells (ECs) harbor distinct phenotypical and functional characteristics depending on their tissue localization and contribute to brain, eye, lung, and muscle diseases such as dementia, macular degeneration, pulmonary hypertension, and sarcopenia. To study their function, isolation of pure ECs in high quantities is crucial. Here, we describe protocols for rapid and reproducible blood vessel EC purification established for scRNA sequencing from murine tissues using mechanical and enzymatic digestion followed by magnetic and fluorescence-activated cell sorting.
Endothelial cells (ECs) exhibit phenotypic and functional tissue specificities, critical for studies in the vascular field and beyond. Thus, tissue-specific methods for isolation of highly purified ...ECs are necessary. Kidney, spleen, and testis ECs are relevant players in health and diseases such as chronic kidney disease, acute kidney injury, myelofibrosis, and cancer. Here, we provide tailored protocols for rapid and reproducible EC purification established for scRNA sequencing from these adult murine tissues using the combination of magnetic- and fluorescence-activated cell sorting.
For complete details on the use and execution of these protocols, please refer to Kalucka et al. (2020) and Dumas et al. (2020).
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•Protocols for isolation of murine endothelial cells applicable for scRNA-seq•Efficient isolation of ECs from the kidney, spleen, and testis•Combination of magnetic- and fluorescence-activated cell sorting•High purity and quality of isolated murine endothelial cells evident from scRNA-seq
Endothelial cells (ECs) exhibit phenotypic and functional tissue specificities, critical for studies in the vascular field and beyond. Thus, tissue-specific methods for isolation of highly purified ECs are necessary. Kidney, spleen, and testis ECs are relevant players in health and diseases such as chronic kidney disease, acute kidney injury, myelofibrosis, and cancer. Here, we provide tailored protocols for rapid and reproducible EC purification established for scRNA sequencing from these adult murine tissues using the combination of magnetic- and fluorescence-activated cell sorting.
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