Anesthesia triggers drug delivery to experimental glioma in mice by hijacking caveolar transport

Abstract Background Pharmaceutical intervention in the CNS is hampered by the shielding function of the blood-brain barrier (BBB). To induce clinical anesthesia, general anesthetics such as isoflurane readily penetrate the BBB. Here, we investigated whether isoflurane can be utilized for therapeutic drug delivery. Methods Barrier function in primary endothelial cells was evaluated by transepithelial/transendothelial electrical resistance, and nanoscale STED and SRRF microscopy. In mice, BBB permeability was quantified by extravasation of several fluorescent tracers. Mouse models including the GL261 glioma model were evaluated by MRI, immunohistochemistry, electron microscopy, western blot, and expression analysis. Results Isoflurane enhances BBB permeability in a time- and concentration-dependent manner. We demonstrate that, mechanistically, isoflurane disturbs the organization of membrane lipid nanodomains and triggers caveolar transport in brain endothelial cells. BBB tightness re-establishes directly after termination of anesthesia, providing a defined window for drug delivery. In a therapeutic glioblastoma trial in mice, simultaneous exposure to isoflurane and cytotoxic agent improves efficacy of chemotherapy. Conclusions Combination therapy, involving isoflurane-mediated BBB permeation with drug administration has far-reaching therapeutic implications for CNS malignancies.

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Abstract P808: The Main Peptide Ssubstrates of Neurolysin Enhance Brain Microvascular Permeability in a Human in vitro Model

Stroke ◽

10.1161/str.52.suppl_1.p808 ◽

2021 ◽

Vol 52 (Suppl_1) ◽

Author(s):

Abraham Al-Ahmad ◽

Vardan T Karamyan

Keyword(s):

Direct Action ◽

Induced Pluripotent Stem Cell ◽

Microvascular Permeability ◽

Dependent Manner ◽

Direct Effects ◽

Edema Formation ◽

Concentration Dependent Manner ◽

Therapeutic Implications ◽

Bbb Permeability

Increased brain microvascular permeability and disruption of blood-brain barrier (BBB) function are among hallmarks of ischemic stroke. Recently, peptidase neurlysin (Nln) has been identified as a compensatory and cerebroprotective mechanism in the post-stroke brain that functions to process a diverse group of extracellular neuropeptides, including bradykinin (BK), neurotensin (NT) and substance P (SP). A number of studies suggest involvement of BK, NT and SP in BBB impairment and edema formation after stroke, however there is paucity of data in regards to the direct effects of these peptides on the brain microvascular endothelial cells (BMECs) and BBB. The purpose of this study was to evaluate the direct effects of BK, NT and SP on permeability of BBB in an in vitro model based on human, induced pluripotent stem cell (iPSC)-derived BMECs. Our data indicate that all three peptides increase BBB permeability in a concentration-dependent manner in an in vitro model formed from two different iPSC lines (CTR90F and CTR65M) and widely used hCMEC/D3 human BMECs. Combination of BK, NT and SP at a sub-effective concentration also resulted in increased BBB permeability in the iPSC-derived model. Furthermore, we observed abrogation of BK, NT and SP effects with pretreatment of pharmacological blockers targeting their specific receptors or in presence of recombinant neurolysin (Nln). This is the first experimental study to document increased permeability of BBB in response to direct action of NT in an in vitro model. In addition, our study confirms the expected but not well-documented, direct effect of SP on BBB permeability and adds to the well-recognized actions of BK on BBB. Lastly, we demonstrate that peptidase Nln can neutralize the effects of these peptides on BBB, suggesting potential therapeutic implications.

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Citrus bergamiaRisso Elevates Intracellular Ca2+in Human Vascular Endothelial Cells due to Release of Ca2+from Primary Intracellular Stores

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2013/759615 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Purum Kang ◽

Seung Ho Han ◽

Hea Kyung Moon ◽

Jeong-Min Lee ◽

Hyo-Keun Kim ◽

...

Keyword(s):

Endothelial Cells ◽

Channel Blocker ◽

Vascular Endothelial Cells ◽

Umbilical Vein ◽

Dependent Manner ◽

Vascular Endothelial ◽

Concentration Dependent Manner ◽

Carbonyl Cyanide ◽

Intracellular Ca ◽

Umbilical Vein Endothelial Cells

The purpose of the present study is to examine the effects of essential oil ofCitrus bergamiaRisso (bergamot, BEO) on intracellular Ca2+in human umbilical vein endothelial cells. Fura-2 fluorescence was used to examine changes in intracellular Ca2+concentration[Ca2+]i. In the presence of extracellular Ca2+, BEO increased[Ca2+]i, which was partially inhibited by a nonselective Ca2+channel blocker La3+. In Ca2+-free extracellular solutions, BEO increased[Ca2+]iin a concentration-dependent manner, suggesting that BEO mobilizes intracellular Ca2+. BEO-induced[Ca2+]iincrease was partially inhibited by a Ca2+-induced Ca2+release inhibitor dantrolene, a phospholipase C inhibitor U73122, and an inositol 1,4,5-triphosphate (IP3)-gated Ca2+channel blocker, 2-aminoethoxydiphenyl borane (2-APB). BEO also increased[Ca2+]iin the presence of carbonyl cyanide m-chlorophenylhydrazone, an inhibitor of mitochondrial Ca2+uptake. In addition, store-operated Ca2+entry (SOC) was potentiated by BEO. These results suggest that BEO mobilizes Ca2+from primary intracellular stores via Ca2+-induced and IP3-mediated Ca2+release and affect promotion of Ca2+influx, likely via an SOC mechanism.

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Effect of angiotensin-converting-enzyme inhibition on bradykinin metabolism by vascular endothelial cells

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1993.264.5.h1493 ◽

1993 ◽

Vol 264 (5) ◽

pp. H1493-H1497 ◽

Cited By ~ 3

Author(s):

M. Grafe ◽

C. Bossaller ◽

K. Graf ◽

W. Auch-Schwelk ◽

C. R. Baumgarten ◽

...

Keyword(s):

Endothelial Cells ◽

Angiotensin Converting Enzyme ◽

Vascular Endothelial Cells ◽

Ace Inhibition ◽

Angiotensin Converting Enzyme Inhibition ◽

Dependent Manner ◽

Converting Enzyme ◽

Concentration Dependent Manner ◽

Cell Monolayers ◽

Converting Enzyme Inhibition

The degradation of bradykinin by angiotensin-converting-enzyme (ACE) activity in cultured human endothelial cells was studied by direct measurement of bradykinin and by its effect on the release of endothelium-derived relaxing factors. The half-life of exogenous bradykinin (10,000 pg/ml) was calculated from the decay of the bradykinin concentration as 46 +/- 2 min in cell monolayers, 133 +/- 15 min in conditioned medium, and 24 +/- 2 min in homogenates. Most of the bradykinin-degrading activity in cell monolayers could be inhibited in a concentration-dependent manner by the ACE inhibitors lisinopril, ramiprilat, and captopril. Bradykinin-degrading activity was released into the culture medium containing one-fourth of the bradykinin-degrading activity found in the presence of cell monolayers. In cell homogenates higher unspecific bradykinin-degrading activities were present. The functional consequence of bradykinin degradation was demonstrated by the potentiating effect of ramiprilat on the generation of endothelium-derived relaxing factors nitric oxide and prostacyclin from endothelial cells. The study supports the concept of increased vasodilatory effects of bradykinin during ACE inhibition.

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PMA-activated neutrophils decrease ectoenzyme activities in rabbit aortic endothelial cells in culture

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.1992.263.6.l657 ◽

1992 ◽

Vol 263 (6) ◽

pp. L657-L663

Author(s):

X. Chen ◽

M. Tzanela ◽

M. K. Baumgartner ◽

J. R. McCormick ◽

J. D. Catravas

Keyword(s):

Endothelial Cells ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Aortic Endothelial Cells ◽

Endothelial Monolayers ◽

Activated Neutrophils ◽

Ace Activity ◽

Dose Dependent Decrease ◽

Dose Dependent ◽

Aortic Endothelial

We have studied the effects of phorbol 12-myristate 13-acetate (PMA)-activated neutrophils [polymorphonuclear leukocytes (PMN)] on endothelial ectoenzyme [angiotensin-converting enzyme (ACE) and 5'-nucleotidase (NCT)] activities in cultured rabbit aortic endothelial cells (EC) with the use of [3H]benzoyl-Phe-Ala-Pro and 14C-labeled AMP as substrates, respectively, under first-order reaction conditions. PMA (1–1,000 ng/ml) or PMN alone had no effect on ACE activity. When PMA was incubated together with PMN (PMN/EC = 1.25:1 or 2.5 x 10(5) neutrophils/ml) for 4 h in Earle's salts, a PMA dose-dependent decrease in ACE activity was observed. Threshold PMA concentration was 2 ng/ml. At 8 ng PMA/ml, ACE activity was totally abolished, without any evidence of cytotoxicity, as inferred from release of 51Cr from prelabeled EC. The decrease in ACE activity was also dependent on PMN concentration and was detectable at PMN/EC values as low as 1.25:10 (0.25 x 10(5) PMN/ml). Inhibition of ACE occurred as early as 1 h after incubation (PMA 10 ng/ml, PMN/EC = 1.25:1). PMA alone caused a small but significant increase in NCT activity, whereas PMA coincubation with PMN produced a significant decrease in NCT activity (20–29%), which was PMA and PMN concentration independent. PMA increased PMN adherence to endothelial monolayers in a concentration-dependent manner. Pretreating PMN with monoclonal antibody 60.3 (raised against the adhesion glycoprotein CD18) or placing a 2-microns filter between PMN and EC, protected the decrease in ACE activity.(ABSTRACT TRUNCATED AT 250 WORDS)

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Vascular Protective Effects of Xanthotoxin and Its Action Mechanism in Rat Aorta and Human Vascular Endothelial Cells

Journal of Vascular Research ◽

10.1159/000509112 ◽

2020 ◽

Vol 57 (6) ◽

pp. 313-324

Author(s):

Li-Hua Cao ◽

Ho Sub Lee ◽

Zhe-Shan Quan ◽

Yun Jung Lee ◽

Yu Jin

Keyword(s):

Endothelial Cells ◽

Cell Adhesion ◽

Adhesion Molecule ◽

Molecular Mechanisms ◽

Umbilical Vein ◽

Neuroprotective Effect ◽

Intercellular Adhesion Molecule ◽

Dependent Manner ◽

Protective Effects ◽

Concentration Dependent Manner

Objective: Xanthotoxin (XAT) is a linear furanocoumarin mainly extracted from the plants Ammi majus L. XAT has been reported the apoptosis of tumor cells, anti-convulsant, neuroprotective effect, antioxidative activity, and vasorelaxant effects. This study aimed to investigate the vascular protective effects and underlying molecular mechanisms of XAT. Methods: XAT’s activity was studied in rat thoracic aortas, isolated with aortic rings, and human umbilical vein endothelial cells (HUVECs). Results: XAT induced endothelium-dependent vasodilation in a concentration-dependent manner in the isolated rat thoracic aortas. Removal of endothelium or pretreatment of aortic rings with L-NAME, 1H-[1,2,4]-oxadiazolo-[4,3-a]-quinoxalin-1-one, and wortmannin significantly inhibited XAT-induced relaxation. In addition, treatment with thapsigargin, 2-aminoethyl diphenylborinate, Gd3+, and 4-aminopyridine markedly attenuated the XAT-induced vasorelaxation. XAT increased nitric oxide production and Akt- endothelial NOS (eNOS) phosphorylation in HUVECs. Moreover, XAT attenuated the expression of TNF-α-induced cell adhesion molecules such as intercellular adhesion molecule, vascular cell adhesion molecule-1, and E-selectin. However, this effect was attenuated by the eNOS inhibitors L-NAME and asymmetric dimethylarginine. Conclusions: This study suggests that XAT induces vasorelaxation through the Akt-eNOS-cGMP pathway by activating the KV channel and inhibiting the L-type Ca2+ channel. Furthermore, XAT exerts an inhibitory effect on vascular inflammation, which is correlated with the observed vascular protective effects.

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Modulation of inhibitory and excitatory fast neurotransmission in the rat CNS by heavy water (D2O)

Journal of Neurophysiology ◽

10.1152/jn.00801.2014 ◽

2015 ◽

Vol 114 (2) ◽

pp. 1109-1118 ◽

Cited By ~ 1

Author(s):

Masahito Wakita ◽

Naoki Kotani ◽

Kiyomitsu Shoudai ◽

Toshitaka Yamaga ◽

Norio Akaike

Keyword(s):

Heavy Water ◽

Deuterium Oxide ◽

Dependent Manner ◽

General Anesthetics ◽

Concentration Dependent Manner ◽

Excitatory Postsynaptic Currents ◽

Whole Cell ◽

Postsynaptic Currents ◽

Cell Current ◽

Whole Cell Current

The effects of heavy water (deuterium oxide, D2O) on GABAergic and glutamatergic spontaneous and evoked synaptic transmission were investigated in acute brain slice and isolated “synaptic bouton” preparations of rat hippocampal CA3 neurons. The substitution of D2O for H2O reduced the frequency and amplitude of GABAergic spontaneous inhibitory postsynaptic currents (sIPSCs) in a concentration-dependent manner but had no effect on glutamatergic spontaneous excitatory postsynaptic currents (sEPSCs). In contrast, for evoked synaptic responses in isolated neurons, the amplitude of both inhibitory and excitatory postsynaptic currents (eIPSCs and eEPSCs) was decreased in a concentration-dependent manner. This was associated with increases of synaptic failure rate ( Rf) and paired-pulse ratio (PPR). The effect was larger for eIPSCs compared with eEPSCs. These results clearly indicate that D2O acts differently on inhibitory and excitatory neurotransmitter release machinery. Furthermore, D2O significantly suppressed GABAA receptor-mediated whole cell current ( IGABA) but did not affect glutamate receptor-mediated whole cell current ( IGlu). The combined effects of D2O at both the pre- and postsynaptic sites may explain the greater inhibition of eIPSCs compared with eEPSCs. Finally, D2O did not enhance or otherwise affect the actions of the general anesthetics nitrous oxide and propofol on spontaneous or evoked GABAergic and glutamatergic neurotransmissions, or on IGABA and IGlu. Our results suggest that previously reported effects of D2O to mimic and/or modulate anesthesia potency result from mechanisms other than modulation of GABAergic and glutamatergic neurotransmission.

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INCREASED C3 IN THE AGING BRAIN PROMOTES INFLAMMATORY TRANSITION IN ENDOTHELIAL CELLS

Innovation in Aging ◽

10.1093/geroni/igz038.3093 ◽

2019 ◽

Vol 3 (Supplement_1) ◽

pp. S840-S840

Author(s):

Nicholas E Propson ◽

Alexandra Litvinchuk ◽

Ethan R Roy ◽

Bianca Contreras ◽

Wei Cao ◽

...

Keyword(s):

Endothelial Cells ◽

Disease Onset ◽

Strong Relationship ◽

Complement C3 ◽

Aging Brain ◽

Aged Mouse ◽

Dependent Manner ◽

Brain Vasculature ◽

Age Related ◽

Bbb Permeability

Abstract Innate immunity has been implicated in normal aging, and age-related disease. The connection between age-related neuroinflammation and change in brain vasculature prior to disease onset remains poorly understood. The complement pathway is an established mediator of neuroinflammation, and increased complement C3 is seen in the aging brain. Thus, we asked whether C3 can promote changes in brain vasculature. We found age dependent increase of brain C3 levels in C57BL/6J mice. Furthermore, we found an increase in expression of adhesion molecule VCAM-1 in endothelial cells (ECs) of the cortex and hippocampus, which was rescued in aged C3a receptor null (C3ar1-/-) mice and aged C3a receptor (C3aR) antagonist treated mice. We confirmed these results by qPCR analysis for Vcam1 in sorted ECs. Human brain microvascular endothelial cells (HBMECs) treated with C3a showed increased expression of VCAM-1, but not other adhesion molecules. Sorted ECs from C3ar1-/- mice challenged with LPS confirmed these findings. Furthermore, C3aR signaling in ECs showed increased blood-brain barrier (BBB) permeability using trans-endothelial electrical resistance (TEER), and BBB impermeable dye injections. HBMECs treated with C3a revealed mis-localization of VE-Cadherin, followed by reduction in protein level when analyzed by immunofluorescence, which promotes increased barrier permeability. As a functional consequence of VCAM-1 expression and increased BBB permeability we found aged mouse brains have increased peripheral lymphocyte (CD45+/CD11b-) infiltration, which was reduced in a C3aR dependent manner. In conclusion, our work suggests there is a strong relationship between C3 expression and vascular C3aR contributing to a functional transition in endothelial cells during aging.

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Sevoflurane Blocks Cholinergic Synaptic Transmission Postsynaptically but Does Not Affect Short-term Potentiation

Anesthesiology ◽

10.1097/00000542-200505000-00010 ◽

2005 ◽

Vol 102 (5) ◽

pp. 920-928 ◽

Cited By ~ 17

Author(s):

Hiroaki Naruo ◽

Shin Onizuka ◽

David Prince ◽

Mayumi Takasaki ◽

Naweed I. Syed

Keyword(s):

Synaptic Plasticity ◽

Synaptic Transmission ◽

Fluorescent Imaging ◽

Posttetanic Potentiation ◽

Dependent Manner ◽

General Anesthetics ◽

Short Term ◽

Concentration Dependent Manner ◽

Cholinergic Synaptic Transmission ◽

Term Potentiation

Background As compared with their effects on both inhibitory and excitatory synapses, little is known about the mechanisms by which general anesthetics affect synaptic plasticity that forms the basis for learning and memory at the cellular level. To test whether clinically relevant concentrations of sevoflurane affect short-term potentiation involving cholinergic synaptic transmission, the soma-soma synapses between identified, postsynaptic neurons were used. Methods Uniquely identifiable neurons visceral dorsal 4 (presynaptic) and left pedal dorsal 1 (postsynaptic) of the mollusk Lymnaea stagnalis were isolated from the intact ganglion and paired overnight in a soma-soma configuration. Simultaneous intracellular recordings coupled with fluorescent imaging of the FM1-43 dye were made in either the absence or the presence of sevoflurane. Results Cholinergic synapses, similar to those observed in vivo, developed between the neurons, and the synaptic transmission exhibited classic short-term, posttetanic potentiation. Action potential-induced (visceral dorsal 4), 1:1 excitatory postsynaptic potentials were reversibly and significantly suppressed by sevoflurane in a concentration-dependent manner. Fluorescent imaging with the dye FM1-43 revealed that sevoflurane did not affect presynaptic exocytosis or endocytosis; instead, postsynaptic nicotinic acetylcholine receptors were blocked in a concentration-dependent manner. To test the hypothesis that sevoflurane affects short-term potentiation, a posttetanic potentiation paradigm was used, and synaptic transmission was examined in either the presence or the absence of sevoflurane. Although 1.5% sevoflurane significantly reduced synaptic transmission between the paired cells, it did not affect the formation or retention of posttetanic potentiation at this synapse. Conclusions This study demonstrates that sevoflurane blocks cholinergic synaptic transmission postsynaptically but does not affect short-term synaptic plasticity at the visceral dorsal 4-left pedal dorsal 1 synapse.

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Differential regulation of metabolism by nitric oxide andS-nitrosothiols in endothelial cells

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00210.2011 ◽

2011 ◽

Vol 301 (3) ◽

pp. H803-H812 ◽

Cited By ~ 21

Author(s):

Anne R. Diers ◽

Katarzyna A. Broniowska ◽

Victor M. Darley-Usmar ◽

Neil Hogg

Keyword(s):

Nitric Oxide ◽

Endothelial Cells ◽

Oxidative Phosphorylation ◽

Metabolic Pathways ◽

Nitrosative Stress ◽

Surrogate Marker ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

No Donor

S-nitrosation of thiols in key proteins in cell signaling pathways is thought to be an important contributor to nitric oxide (NO)-dependent control of vascular (patho)physiology. Multiple metabolic enzymes are targets of both NO and S-nitrosation, including those involved in glycolysis and oxidative phosphorylation. Thus it is important to understand how these metabolic pathways are integrated by NO-dependent mechanisms. Here, we compared the effects of NO and S-nitrosation on both glycolysis and oxidative phosphorylation in bovine aortic endothelial cells using extracellular flux technology to determine common and unique points of regulation. The compound S-nitroso-l-cysteine (l-CysNO) was used to initiate intracellular S-nitrosation since it is transported into cells and results in stable S-nitrosation in vitro. Its effects were compared with the NO donor DetaNONOate (DetaNO). DetaNO treatment caused only a decrease in the reserve respiratory capacity; however, l-CysNO impaired both this parameter and basal respiration in a concentration-dependent manner. In addition, DetaNO stimulated extracellular acidification rate (ECAR), a surrogate marker of glycolysis, whereas l-CysNO stimulated ECAR at low concentrations and inhibited it at higher concentrations. Moreover, a temporal relationship between NO- and S-nitrosation-mediated effects on metabolism was identified, whereby NO caused a rapid impairment in mitochondrial function, which was eventually overwhelmed by S-nitrosation-dependent processes. Taken together, these results suggest that severe pharmacological nitrosative stress may differentially regulate metabolic pathways through both intracellular S-nitrosation and NO-dependent mechanisms. Moreover, these data provide insight into the role of NO and related compounds in vascular (patho)physiology.

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The mechanism of low molecular weight heparin (LMWH) inhibition of tumor growth

Journal of Clinical Oncology ◽

10.1200/jco.2006.24.18_suppl.13093 ◽

2006 ◽

Vol 24 (18_suppl) ◽

pp. 13093-13093 ◽

Cited By ~ 4

Author(s):

S. L. Smiley ◽

D. O. Henry ◽

M. K. Wong

Keyword(s):

Endothelial Cells ◽

Tumor Growth ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Receptor System ◽

Fgf Receptor ◽

Tumor Inhibition ◽

Inhibition Of Tumor Growth

13093 Background: Clinical studies show that LMWHs improve survival in cancer patients. There is compelling and mounting evidence that non-anticoagulation factors are at play, and that these may be contributing in a major way to improved patient outcome. Methods and Results: Dalteparin, enoxaparin, and tinzaparin were tested for their in vivo ability to inhibit tumor lines engineered for aggressive angiogenesis-driven growth. Therapeutic daily doses of drug administered the day following tumor inoculation resulted in significant angiogenesis and tumor inhibition. We previously showed that LMWHs inhibit fibroblast growth factor (FGF) -induced mitogenesis of Tumor Derived Endothelial Cells (TDECs) in a time and concentration dependent manner in vitro. We now show that this endothelial inhibition occurs through LMWHs-mediated reduction of phosphorylation and down stream signaling through ERK. The potency of LMWH was significantly reduced when TDECs were pretreated with heparinase- suggesting that the molecular target for LMWH may be the cell surface, low affinity FGF receptor system. Both our in vivo and in vitro studies demonstrate that angiogenesis and tumor inhibition are greatest for dalteparin > tinzaparin > enoxaparin. Clues to the heparin-TDECs interaction comes from tracking the real-time movement of FGF using a highly fluorescent nanocrystal bead decorated on its surface with FGF. High resolution video-microscopy shows FGF binding onto TDEC surfaces, but once heparin enters the environment, FGF detaches from the TDECs and migrates to the heparin. This ultimately results in significant TDEC growth inhibition as compared to controls. Conclusion: LMWH treatment at pharmacologic doses significantly blunts tumor growth and angiogenesis. This inhibition resides in part via heparin’s ability to sequester FGF from the low affinity receptor system on tumor endothelial cells. No significant financial relationships to disclose.

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