scholarly journals Critical role for lactate dehydrogenase A in aerobic glycolysis that sustains pulmonary microvascular endothelial cell proliferation

2010 ◽  
Vol 299 (4) ◽  
pp. L513-L522 ◽  
Author(s):  
Glenda Parra-Bonilla ◽  
Diego F. Alvarez ◽  
Abu-Bakr Al-Mehdi ◽  
Mikhail Alexeyev ◽  
Troy Stevens
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Lactate Dehydrogenase ◽  
Lactic Acidosis ◽  
Aerobic Glycolysis ◽  
Microvascular Endothelial Cells ◽  
Microvascular Endothelial Cell ◽  
Pulmonary Microvascular Endothelial Cells ◽  
Pulmonary Microvascular Endothelial Cell ◽  
Microvascular Endothelial

Pulmonary microvascular endothelial cells possess both highly proliferative and angiogenic capacities, yet it is unclear how these cells sustain the metabolic requirements essential for such growth. Rapidly proliferating cells rely on aerobic glycolysis to sustain growth, which is characterized by glucose consumption, glucose fermentation to lactate, and lactic acidosis, all in the presence of sufficient oxygen concentrations. Lactate dehydrogenase A converts pyruvate to lactate necessary to sustain rapid flux through glycolysis. We therefore tested the hypothesis that pulmonary microvascular endothelial cells express lactate dehydrogenase A necessary to utilize aerobic glycolysis and support their growth. Pulmonary microvascular endothelial cell (PMVEC) growth curves were conducted over a 7-day period. PMVECs consumed glucose, converted glucose into lactate, and acidified the media. Restricting extracellular glucose abolished the lactic acidosis and reduced PMVEC growth, as did replacing glucose with galactose. In contrast, slow-growing pulmonary artery endothelial cells (PAECs) minimally consumed glucose and did not develop a lactic acidosis throughout the growth curve. Oxygen consumption was twofold higher in PAECs than in PMVECs, yet total cellular ATP concentrations were twofold higher in PMVECs. Glucose transporter 1, hexokinase-2, and lactate dehydrogenase A were all upregulated in PMVECs compared with their macrovascular counterparts. Inhibiting lactate dehydrogenase A activity and expression prevented lactic acidosis and reduced PMVEC growth. Thus PMVECs utilize aerobic glycolysis to sustain their rapid growth rates, which is dependent on lactate dehydrogenase A.

scholarly journals Mechanism of C-type natriuretic peptide-induced endothelial cell hyperpolarization

2009 ◽  
Vol 296 (2) ◽  
pp. L248-L256 ◽  
Author(s):  
Aaron Simon ◽  
Elizabeth O. Harrington ◽  
Gong Xin Liu ◽  
Gideon Koren ◽  
Gaurav Choudhary
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Ion Channels ◽  
Natriuretic Peptide ◽  
Second Messengers ◽  
Microvascular Endothelial Cells ◽  
Patch Clamping ◽  
Perforated Patch ◽  
Pulmonary Microvascular Endothelial Cells ◽  
Microvascular Endothelial

C-type natriuretic peptide (CNP) has a demonstrated hyperpolarizing effect on vascular smooth muscle cells. However, its autocrine function, including its electrophysiological effect on endothelial cells, is not known. Here, we report the effect of CNP on the membrane potential ( Em) of pulmonary microvascular endothelial cells and describe its target receptors, second messengers, and ion channels. We measured changes in Em using fluorescence imaging and perforated patch-clamping techniques. In imaging experiments, samples were preincubated in the potentiometric dye DiBAC4(3), and subsequently exposed to CNP in the presence of selective inhibitors of ion channels or second messengers. CNP exposure induced a dose-dependent decrease in fluorescence, indicating that CNP induces endothelial cell hyperpolarization. CNP-induced hyperpolarization was inhibited by the K+ channel blockers, tetraethylammonium or iberiotoxin, the nonspecific cation channel blocker, La3+, or by depletion or repletion of extracellular Ca2+ or K+, respectively. CNP-induced hyperpolarization was also blocked by pharmacological inhibition of PKG or by small interfering RNA (siRNA)-mediated knockdown of natriuretic peptide receptor-B (NPR-B). CNP-induced hyperpolarization was mimicked by the PKG agonist, 8-bromo-cGMP, and attenuated by both the endothelial nitric oxide synthase (eNOS) inhibitor, Nω-nitro-l-arginine methyl ester (l-NAME), and the soluble guanylyl cyclase (sGC) inhibitor, 1H-[1,2,4]oxadiazolo[4,3- a]quinoxalin-1-one. Presence of iberiotoxin-sensitive, CNP-induced outward current was confirmed by perforated patch-clamping experiments. We conclude that CNP hyperpolarizes pulmonary microvascular endothelial cells by activating large-conductance calcium-activated potassium channels mediated by the activation of NPR-B, PKG, eNOS, and sGC.

scholarly journals Retroviral transformation of cerebral microvascular endothelial cells: macrophage-like and microvascular endothelial cell properties

Blood ◽  
1991 ◽  
Vol 77 (2) ◽  
pp. 294-305
Author(s):  
DH Robinson ◽  
MK Warren ◽  
LT Liang ◽  
JJ Oprandy ◽  
TB Nielsen ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Self Organization ◽  
Microvascular Endothelial Cells ◽  
Microvascular Endothelial Cell ◽  
Focus Formation ◽  
Transformed Cell ◽  
L Cell ◽  
Microvascular Endothelial

We report that L-cell-conditioned medium (LCM) transforms porcine cerebral microvascular (PCMV) endothelial cells into cells with macrophage-like properties. LCM is known to contain both cytokine(s) and the L-cell virus, a murine retrovirus found in the L929 cell and LCM. Our evidence suggests that both LCM cytokine(s) and the L-cell virus are involved in this PCMV endothelial cell transformation. Criteria for transformation include focus formation, decreased serum requirements for growth, changes in morphology including nonadherence, propagation in suspension culture, and a decreased growth response to stimulation with a known endothelial cell mitogen. Macrophage-like characteristics of this transformed cell, designated as RVTE, include pinocytosis of low-density lipoprotein, Fc receptor-mediated phagocytosis, phagocytosis of bacteria and zymosan, the expression of macrophage enzyme markers, and constitutive production of colony- stimulating factor 1. However, the transformed cell retains several properties of the nontransformed cell including the expression of FVIII:RAg and in vitro self-organization into capillary-like structures. Cloning of RVTE cells clearly shows that both macrophage- like and cerebral microvascular endothelial cell properties are present in the same cell. During self-organization, nontransformed cells express morphologic and functional characteristics classically associated with the macrophage. These findings suggest that some brain capillary pathophysiologies could involve macrophage-like cerebral microvascular endothelial cells. Furthermore, the “reticuloendothelial” phenotypic repertoire expressed by this transformed cerebral microvascular endothelial cell may show that the cerebral capillary endothelial cell in vivo is derived from a hematopoietic and/or phagocytic precursor.

scholarly journals Pneumolysin Is the Main Inducer of Cytotoxicity to Brain Microvascular Endothelial Cells Caused by Streptococcus pneumoniae

2001 ◽  
Vol 69 (2) ◽  
pp. 845-852 ◽  
Author(s):  
Gregor Zysk ◽  
Barbara Katharina Schneider-Wald ◽  
Jae Hyuk Hwang ◽  
Levente Bejo ◽  
Kwang Sik Kim ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Streptococcus Pneumoniae ◽  
Pneumococcal Meningitis ◽  
Primary Cultures ◽  
Cell Monolayer ◽  
Microvascular Endothelial Cells ◽  
Microvascular Endothelial Cell ◽  
Brain Microvascular Endothelial Cells ◽  
Microvascular Endothelial

ABSTRACT In pneumococcal meningitis it is assumed that bacteria cross the blood-brain barrier (BBB), which consists mainly of cerebral endothelial cells. The effect of Streptococcus pneumoniaeon the BBB was investigated with an in vitro BBB model using a human brain microvascular endothelial cell line (HBMEC) and primary cultures of bovine brain microvascular endothelial cells (BBMEC). Within a few hours of incubation with pneumococci, rounding and detachment of the HBMEC were observed, and the transendothelial electrical resistance of the BBMEC monolayer decreased markedly. An S. pneumoniaemutant deficient in pneumolysin did not affect the integrity of the endothelial cell monolayer. Neither cell wall fragments nor isolated pneumococcal cell walls induced changes of endothelial cell morphology. However, purified pneumolysin caused endothelial cell damage comparable to that caused by the viable pneumococci. The cell detachment was dependent on de novo protein synthesis and required the activities of caspase and tyrosine kinases. The results show that pneumolysin is an important component for damaging the BBB and may contribute to the entry of pneumococci into the cerebral compartment and to the development of brain edema in pneumococcal meningitis.

scholarly journals Retroviral transformation of cerebral microvascular endothelial cells: macrophage-like and microvascular endothelial cell properties

Blood ◽  
1991 ◽  
Vol 77 (2) ◽  
pp. 294-305 ◽  
Author(s):  
DH Robinson ◽  
MK Warren ◽  
LT Liang ◽  
JJ Oprandy ◽  
TB Nielsen ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Self Organization ◽  
Microvascular Endothelial Cells ◽  
Microvascular Endothelial Cell ◽  
Focus Formation ◽  
Transformed Cell ◽  
L Cell ◽  
Microvascular Endothelial

Abstract We report that L-cell-conditioned medium (LCM) transforms porcine cerebral microvascular (PCMV) endothelial cells into cells with macrophage-like properties. LCM is known to contain both cytokine(s) and the L-cell virus, a murine retrovirus found in the L929 cell and LCM. Our evidence suggests that both LCM cytokine(s) and the L-cell virus are involved in this PCMV endothelial cell transformation. Criteria for transformation include focus formation, decreased serum requirements for growth, changes in morphology including nonadherence, propagation in suspension culture, and a decreased growth response to stimulation with a known endothelial cell mitogen. Macrophage-like characteristics of this transformed cell, designated as RVTE, include pinocytosis of low-density lipoprotein, Fc receptor-mediated phagocytosis, phagocytosis of bacteria and zymosan, the expression of macrophage enzyme markers, and constitutive production of colony- stimulating factor 1. However, the transformed cell retains several properties of the nontransformed cell including the expression of FVIII:RAg and in vitro self-organization into capillary-like structures. Cloning of RVTE cells clearly shows that both macrophage- like and cerebral microvascular endothelial cell properties are present in the same cell. During self-organization, nontransformed cells express morphologic and functional characteristics classically associated with the macrophage. These findings suggest that some brain capillary pathophysiologies could involve macrophage-like cerebral microvascular endothelial cells. Furthermore, the “reticuloendothelial” phenotypic repertoire expressed by this transformed cerebral microvascular endothelial cell may show that the cerebral capillary endothelial cell in vivo is derived from a hematopoietic and/or phagocytic precursor.

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