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1.
Am J Respir Crit Care Med ; 209(8): 1001-1012, 2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38113165

ABSTRACT

Rationale: Obstructive sleep apnea (OSA) is a highly prevalent condition that is associated with accelerated biological aging and multiple end-organ morbidities. Current treatments, such as continuous positive airway pressure (CPAP), have shown limited cognitive, metabolic, and cardiovascular beneficial outcomes despite adherence. Thus, adjunct therapies aiming to reduce OSA burden, such as senolytics, could improve OSA outcomes.Objectives: To assess if targeting senescence in addition to partial normoxia mimicking "good" CPAP adherence can improve physiological outcomes in mice exposed to chronic intermittent hypoxia.Methods: We compared the effects of 6 weeks of therapy with either partial normoxic recovery alone or combined with the senolytic navitoclax after 16 weeks of intermittent hypoxia exposures, a hallmark of OSA, on multiphenotypic cardiometabolic and neurocognitive parameters.Measurements and Main Results: Our findings indicate that only when combined with navitoclax, partial normoxic recovery significantly improved sleepiness (sleep in the dark phase: 34% ± 4% vs. 26% ± 3%; P < 0.01), cognition (preference score: 51% ± 19% vs. 70% ± 11%; P = 0.048), coronary artery function (response to acetylcholine [vasodilation]: 56% ± 13% vs. 72% ± 10%; P < 0.001), glucose, and lipid metabolism and reduced intestinal permeability and senescence in multiple organs.Conclusions: These findings indicate that the reversibility of end-organ morbidities induced by OSA is not only contingent on restoration of normal oxygenation patterns but can be further enhanced by targeting other OSA-mediated detrimental cellular processes, such as accelerated senescence.


Subject(s)
Aniline Compounds , Senotherapeutics , Sleep Apnea, Obstructive , Sulfonamides , Animals , Mice , Disease Models, Animal , Multiple Organ Failure , Hypoxia/complications , Continuous Positive Airway Pressure
2.
Arch. bronconeumol. (Ed. impr.) ; 59(12): 805-812, dic. 2023. ilus, graf
Article in English | IBECS | ID: ibc-228400

ABSTRACT

Introduction: Obstructive sleep apnea (OSA) is a chronic condition characterized by intermittent hypoxia (IH) and sleep fragmentation (SF). OSA can induce excessive daytime sleepiness (EDS) and is associated with impaired cognition and anxiety. Solriamfetol (SOL) and modafinil (MOD) are widely used wake-promoting agents in OSA patients with EDS. Methods: Male C57Bl/6J mice were exposed to SF along with sleep controls (SC) or to IH and room air (RA) controls during the light (inactive) phase for 4 and 16 weeks, respectively. Both IH and SF exposures were then discontinued to mimic “ideal” continuous positive airway pressure (CPAP) adherence. All groups were then randomly assigned to receive once daily intraperitoneal injections of SOL, MOD, or vehicle (VEH) for 6 days. Sleep/wake activity was assessed along with tests of explicit memory, anxiety and depression were performed before and after treatments. Results: IH and SF exposures increased sleep percentage in the dark phase and reduced wake bouts lengths (i.e., EDS), and induced cognitive deficits and impulsivity in mice. Both SOL and MOD treatments effectively mitigated EDS when combined with recovery, while recovery alone did not improve EDS over the 6-day period. Furthermore, improvements explicit memory emerged only after SOL. Conclusion: Chronic IH and SF induce EDS in young adult mice that is not ameliorated by recovery except when combined with either SOL or MOD. SOL, but not MOD, significantly improves IH-induced cognitive deficits. Thus, SOL emerges as a viable adjuvant medication for residual EDS in OSA along with its positive impact on cognition. (AU)


Subject(s)
Animals , Mice , Sleep Apnea, Obstructive/complications , Sleep Apnea, Obstructive/therapy , Disorders of Excessive Somnolence/etiology , Wakefulness-Promoting Agents/pharmacology , Wakefulness-Promoting Agents/therapeutic use , Modafinil/pharmacology , Modafinil/therapeutic use , Cognition , Hypoxia
3.
Arch Bronconeumol ; 59(12): 805-812, 2023 Dec.
Article in English, Spanish | MEDLINE | ID: mdl-37783638

ABSTRACT

INTRODUCTION: Obstructive sleep apnea (OSA) is a chronic condition characterized by intermittent hypoxia (IH) and sleep fragmentation (SF). OSA can induce excessive daytime sleepiness (EDS) and is associated with impaired cognition and anxiety. Solriamfetol (SOL) and modafinil (MOD) are widely used wake-promoting agents in OSA patients with EDS. METHODS: Male C57Bl/6J mice were exposed to SF along with sleep controls (SC) or to IH and room air (RA) controls during the light (inactive) phase for 4 and 16 weeks, respectively. Both IH and SF exposures were then discontinued to mimic "ideal" continuous positive airway pressure (CPAP) adherence. All groups were then randomly assigned to receive once daily intraperitoneal injections of SOL, MOD, or vehicle (VEH) for 6 days. Sleep/wake activity was assessed along with tests of explicit memory, anxiety and depression were performed before and after treatments. RESULTS: IH and SF exposures increased sleep percentage in the dark phase and reduced wake bouts lengths (i.e., EDS), and induced cognitive deficits and impulsivity in mice. Both SOL and MOD treatments effectively mitigated EDS when combined with recovery, while recovery alone did not improve EDS over the 6-day period. Furthermore, improvements explicit memory emerged only after SOL. CONCLUSION: Chronic IH and SF induce EDS in young adult mice that is not ameliorated by recovery except when combined with either SOL or MOD. SOL, but not MOD, significantly improves IH-induced cognitive deficits. Thus, SOL emerges as a viable adjuvant medication for residual EDS in OSA along with its positive impact on cognition.


Subject(s)
Disorders of Excessive Somnolence , Sleep Apnea, Obstructive , Wakefulness-Promoting Agents , Humans , Male , Animals , Mice , Wakefulness , Wakefulness-Promoting Agents/pharmacology , Wakefulness-Promoting Agents/therapeutic use , Continuous Positive Airway Pressure , Disease Models, Animal , Sleep Apnea, Obstructive/complications , Sleep Apnea, Obstructive/therapy , Modafinil/pharmacology , Modafinil/therapeutic use , Disorders of Excessive Somnolence/etiology , Hypoxia , Cognition
4.
Int J Mol Sci ; 24(12)2023 Jun 08.
Article in English | MEDLINE | ID: mdl-37373028

ABSTRACT

Obstructive sleep apnea (OSA) is a chronic condition characterized by intermittent hypoxia (IH) and sleep fragmentation (SF). In murine models, chronic SF can impair endothelial function and induce cognitive declines. These deficits are likely mediated, at least in part, by alterations in Blood-brain barrier (BBB) integrity. Male C57Bl/6J mice were randomly assigned to SF or sleep control (SC) conditions for 4 or 9 weeks and in a subset 2 or 6 weeks of normal sleep recovery. The presence of inflammation and microglia activation were evaluated. Explicit memory function was assessed with the novel object recognition (NOR) test, while BBB permeability was determined by systemic dextran-4kDA-FITC injection and Claudin 5 expression. SF exposures resulted in decreased NOR performance and in increased inflammatory markers and microglial activation, as well as enhanced BBB permeability. Explicit memory and BBB permeability were significantly associated. BBB permeability remained elevated after 2 weeks of sleep recovery (p < 0.01) and returned to baseline values only after 6 weeks. Chronic SF exposures mimicking the fragmentation of sleep that characterizes patients with OSA elicits evidence of inflammation in brain regions and explicit memory impairments in mice. Similarly, SF is also associated with increased BBB permeability, the magnitude of which is closely associated with cognitive functional losses. Despite the normalization of sleep patterns, BBB functional recovery is a protracted process that merits further investigation.


Subject(s)
Cognitive Dysfunction , Sleep Apnea, Obstructive , Male , Mice , Animals , Blood-Brain Barrier/metabolism , Neuroinflammatory Diseases , Sleep Deprivation , Sleep Apnea, Obstructive/metabolism , Inflammation/metabolism , Mice, Inbred C57BL , Disease Models, Animal
5.
Sleep Med ; 107: 89-99, 2023 07.
Article in English | MEDLINE | ID: mdl-37137196

ABSTRACT

BACKGROUND: Obstructive sleep apnea (OSA) is a chronic condition characterized by intermittent hypoxia (IH). Excessive daytime sleepiness (EDS) is a common consequence of OSA and is associated with cognitive deficits and anxiety. Modafinil (MOD) and Solriamfetol (SOL) are potent wake-promoting agents clinically used to improve wakefulness in OSA patients with EDS. METHODS: Male C57Bl/6J mice were exposed to either IH or room air (RA) controls during the light phase for 16 weeks. Both groups were then randomly assigned to receive once-daily intraperitoneal injections of SOL (200 mg/kg), MOD (200 mg/kg) or vehicle (VEH) for 9 days while continuing IH exposures. Sleep/wake activity was assessed during the dark (active) phase. Novel object recognition (NOR), elevated-plus maze test (EPMT), and forced swim test (FST) were performed before and after drug treatment. RESULTS: IH exposure increased dark phase sleep percentage and reduced wake bouts lengths and induced cognitive deficits and anxiogenic effects. Both SOL and MOD treatments decreased sleep propensity under IH conditions, but only SOL promoted improvements in NOR performance (explicit memory) and reduced anxiety-like behaviors. CONCLUSION: Chronic IH, a hallmark feature of OSA, induces EDS in young adult mice that is ameliorated by both SOL and MOD. SOL, but not MOD, significantly improves IH-induced cognitive deficits and promotes anxiolytic effects. Thus, SOL could potentially benefit OSA patients beyond EDS management.


Subject(s)
Disorders of Excessive Somnolence , Sleep Apnea, Obstructive , Animals , Male , Mice , Anxiety/drug therapy , Cognition , Disease Models, Animal , Disorders of Excessive Somnolence/complications , Modafinil/therapeutic use , Sleep Apnea, Obstructive/complications , Sleep Apnea, Obstructive/drug therapy , Wakefulness
6.
Sleep ; 46(5)2023 05 10.
Article in English | MEDLINE | ID: mdl-36866452

ABSTRACT

Obstructive sleep apnea (OSA) is a highly prevalent condition characterized by episodes of partial or complete breath cessation during sleep that induces sleep fragmentation (SF). One of the frequent manifestations of OSA is the presence of excessive daytime sleepiness (EDS) associated with cognitive deficits. Solriamfetol (SOL) and modafinil (MOD) are wake-promoting agents commonly prescribed to improve wakefulness in OSA patients with EDS. This study aimed to assess the effects of SOL and MOD in a murine model of OSA characterized by periodic SF. Male C57Bl/6J mice were exposed to either control sleep (SC) or SF (mimicking OSA) during the light period (06:00 h to 18:00 h) for 4 weeks, which consistently induces sustained excessive sleepiness during the dark phase. Both groups were then randomly assigned to receive once-daily intraperitoneal injections of SOL (200 mg/kg), MOD (200 mg/kg), or vehicle for 1 week while continuing exposures to SF or SC. Sleep/wake activity and sleep propensity were assessed during the dark phase. Novel Object Recognition test, Elevated-Plus Maze Test, and Forced Swim Test were performed before and after treatment. SOL or MOD decreased sleep propensity in SF, but only SOL induced improvements in explicit memory, while MOD exhibited increased anxiety behaviors. Chronic SF, a major hallmark of OSA, induces EDS in young adult mice that is mitigated by both SOL and MOD. SOL, but not MOD, significantly improves SF-induced cognitive deficits. Increased anxiety behaviors are apparent in MOD-treated mice. Further studies aiming to elucidate the beneficial cognitive effects of SOL are warranted.


Subject(s)
Disorders of Excessive Somnolence , Sleep Apnea, Obstructive , Male , Animals , Mice , Sleep Deprivation/complications , Sleep Deprivation/drug therapy , Sleep , Sleep Apnea, Obstructive/complications , Sleep Apnea, Obstructive/drug therapy , Modafinil/pharmacology , Modafinil/therapeutic use , Disorders of Excessive Somnolence/complications , Mice, Inbred C57BL
7.
Eur Respir J ; 61(1)2023 01.
Article in English | MEDLINE | ID: mdl-36028255

ABSTRACT

BACKGROUND: Obstructive sleep apnoea (OSA) is a chronic prevalent condition characterised by intermittent hypoxia (IH), and is associated with endothelial dysfunction and coronary artery disease (CAD). OSA can induce major changes in gut microbiome diversity and composition, which in turn may induce the emergence of OSA-associated morbidities. However, the causal effects of IH-induced gut microbiome changes on the vasculature remain unexplored. Our objective was to assess if vascular dysfunction induced by IH is mediated through gut microbiome changes. METHODS: Faecal microbiota transplantation (FMT) was conducted on C57BL/6J naïve mice for 6 weeks to receive either IH or room air (RA) faecal slurry with or without probiotics (VSL#3). In addition to 16S rRNA amplicon sequencing of their gut microbiome, FMT recipients underwent arterial blood pressure and coronary artery and aorta function testing, and their trimethylamine N-oxide (TMAO) and plasma acetate levels were determined. Finally, C57BL/6J mice were exposed to IH, IH treated with VSL#3 or RA for 6 weeks, and arterial blood pressure and coronary artery function assessed. RESULTS: Gut microbiome taxonomic profiles correctly segregated IH from RA in FMT mice and the normalising effect of probiotics emerged. Furthermore, IH-FMT mice exhibited increased arterial blood pressure and TMAO levels, and impairments in aortic and coronary artery function (p<0.05) that were abrogated by probiotic administration. Lastly, treatment with VSL#3 under IH conditions did not attenuate elevations in arterial blood pressure or CAD. CONCLUSIONS: Gut microbiome alterations induced by chronic IH underlie, at least partially, the typical cardiovascular disturbances of sleep apnoea and can be mitigated by concurrent administration of probiotics.


Subject(s)
Coronary Artery Disease , Gastrointestinal Microbiome , Probiotics , Sleep Apnea, Obstructive , Mice , Animals , Gastrointestinal Microbiome/physiology , Disease Models, Animal , RNA, Ribosomal, 16S , Mice, Inbred C57BL , Sleep Apnea, Obstructive/complications , Sleep Apnea, Obstructive/therapy , Hypoxia , Coronary Artery Disease/therapy , Coronary Artery Disease/complications
8.
Neurobiol Sleep Circadian Rhythms ; 13: 100084, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36254342

ABSTRACT

Obstructive sleep apnea (OSA) is a chronic and highly prevalent condition characterized by chronic intermittent hypoxia (IH) and sleep fragmentation (SF), and can lead to a vast array of end-organ morbidities, particularly affecting cardiovascular, metabolic and neurobehavioral functioning. OSA can induce cognitive and behavioral and mood deficits. Male C57Bl/6J 8-week-old mice were housed in custom-designed cages with a silent motorized mechanical sweeper traversing the cage floor at 2-min intervals (SF) during daylight for four weeks. Sleep control (SC) consisted of keeping sweeper immobile. IH consisted of cycling FiO2 21% 90 seconds-6.3% 90s or room air (RA; FiO2 21%) for sixteen weeks and combined SF-IH was conducted for nine weeks. Open field novel object recognition (NOR) testing, elevated-plus maze test (EPMT), and forced swimming test (FST) were performed. SF induced cognitive NOR performance impairments in mice along with reduced anxiety behaviors while IH induced deficits in NOR performance, but increased anxiety behaviors. SF-IH induced impaired performance in NOR test of similar magnitude to IH or SF alone. Combined SF-IH exposures did not affect anxiety behaviors. Thus, both SF an IH altered cognitive function while imposing opposite effects on anxiety behaviors. SF-IH did not magnify the detrimental effects of isolated SF or IH and canceled out the effects on anxiety. Based on these findings, the underlying pathophysiologic processes underlying IH and SF adverse effects on cognitive function appear to differ, while those affecting anxiety counteract each other.

9.
Sci Rep ; 12(1): 12305, 2022 07 19.
Article in English | MEDLINE | ID: mdl-35853902

ABSTRACT

Patients with obstructive sleep apnea/hypopnea (OSA) are at high risk of cerebrovascular diseases leading to cognitive impairment. The oxidative stress generated by intermittent hypoxia (IH) could lead to an increase in blood-brain barrier (BBB) permeability, an essential interface for the protection of the brain. Moreover, in patients with OSA, blood coagulation could be increased leading to cardiovascular complications. Thrombin is a factor found increased in these populations that exerts various cellular effects through activation of protease activated receptors (PARs). Thus, we have evaluated in an in vitro BBB model the association of IH with thrombin at two concentrations. We measured the apparent BBB permeability, expression of tight junctions, ROS production, HIF-1α expression, and cleavage of PAR-1/PAR-3. Pre-treatment with dabigatran was performed. IH and higher thrombin concentrations altered BBB permeability: high levels of HIF-1α expression, ROS and PAR-1 activation compared to PAR-3 in such conditions. Conversely, lower concentration of thrombin associated with IH appear to have a protective effect on BBB with a significant cleavage of PAR-3. Dabigatran reversed the deleterious effect of thrombin at high concentrations but also suppressed the beneficial effect of low dose thrombin. Therefore, thrombin and PARs represent novel attractive targets to prevent BBB opening in OSA.


Subject(s)
Brain , Endothelial Cells , Receptor, PAR-1 , Sleep Apnea, Obstructive , Thrombin , Blood-Brain Barrier/cytology , Blood-Brain Barrier/drug effects , Blood-Brain Barrier/metabolism , Brain/cytology , Brain/drug effects , Brain/metabolism , Dabigatran/pharmacology , Endothelial Cells/cytology , Endothelial Cells/drug effects , Endothelial Cells/metabolism , Humans , Hypoxia/metabolism , Reactive Oxygen Species/metabolism , Receptor, PAR-1/metabolism , Sleep Apnea, Obstructive/metabolism , Thrombin/metabolism
10.
Cell Physiol Biochem ; 54(6): 1231-1248, 2020 Dec 17.
Article in English | MEDLINE | ID: mdl-33326735

ABSTRACT

BACKGROUND/AIMS: Obstructive sleep apnea (OSA) is characterized by repeated episodes of complete or partial obstruction of the upper airways, leading to chronic intermittent hypoxia (IH). OSA patients are considered at high cerebrovascular risk and may also present cognitive impairment. One hypothesis explored is that disturbances may be linked to blood-brain barrier (BBB) dysfunction. The BBB is a protective barrier separating the brain from blood flow. The BBB limits the paracellular pathway through tight and adherens junctions, and the transcellular passage by efflux pumps (ABC transporters). The aims of this study were to evaluate the impact of IH and sustained hypoxia (SH) on a validated in vitro BBB model and to investigate the factors expressed under both conditions. METHODS: Exposure of endothelial cells (HBEC-5i) in our in vitro model of BBB to hypoxia was performed using IH cycles: 1% O2-35 min/18% O2-25 min for 6 cycles or 6 h of SH at 1% O2. After exposure, we studied the cytotoxicity and the level of ROS in our cells. We measured the apparent BBB permeability using sodium fluorescein, FITC-dextran and TEER measurement. Whole cell ELISA were performed to evaluate the expression of tight junctions, ABC transporters, HIF-1α and Nrf2. The functionality of ABC transporters was evaluated with accumulation studies. Immunofluorescence assays were also conducted to illustrate the whole cell ELISAs. RESULTS: Our study showed that 6 h of IH or SH induced a BBB disruption marked by a significant decrease in junction protein expressions (claudin-5, VE-cadherin, ZO-1) and an increase in permeability. We also observed an upregulation in P-gp protein expression and functionality and a downregulation in BCRP. Hypoxia induced production of ROS, Nrf2 and HIF-1α. They were expressed in both sustained and intermittent conditions, but the expression and the activity of P-gp and BCRP were different. CONCLUSION: Understanding these mechanisms seems essential in order to propose new therapeutic strategies for patients with OSA.


Subject(s)
ATP Binding Cassette Transporter, Subfamily G, Member 2/biosynthesis , Blood-Brain Barrier/metabolism , Gene Expression Regulation , Hypoxia, Brain/metabolism , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Models, Cardiovascular , NF-E2-Related Factor 2/metabolism , Neoplasm Proteins/biosynthesis , ATP Binding Cassette Transporter, Subfamily B/biosynthesis , Blood-Brain Barrier/pathology , Cell Line , Humans , Hypoxia, Brain/pathology
11.
Brain Res ; 1719: 57-63, 2019 09 15.
Article in English | MEDLINE | ID: mdl-31121158

ABSTRACT

Anticoagulant therapy presents iatrogenic effects such as intracerebral hemorrhage (ICH). The latest anticoagulants on the market, direct oral anticoagulants (DOACs) such as apixaban, dabigatran and rivaroxaban, are reported to cause less ICH than other anticoagulants. Next to the ICH area, the thrombin is accumulated and the blood-brain barrier (BBB) is opened. The effects of thrombin on the BBB are largely mediated by the protease activated receptor (PAR) family, especially the PAR-1 isoform. Our hypothesis is that DOACs may limit the effects of thrombin on endothelial cells (of the BBB) alteration by a mechanism probably involving PAR-1 activation. To test this hypothesis in vitro, we used HBEC-5i human brain endothelial cells as a human BBB model. The effects of thrombin under warfarin, heparin, rivaroxaban, apixaban, and dabigatran treatment on endothelial cells were then investigated by measuring of permeability and junction proteins: ZO-1 and VE-cadherin expressions and PAR-1 cleavage. Depending on the anticoagulant used, we observed three profiles of response of the endothelial cells after thrombin exposure: i) dabigatran treatment allowed maintaining the tightness of the endothelial monolayer; ii) other DOACs limited thrombin-induced alteration of the endothelial monolayer; and iii) pretreatment with warfarin and heparin did not protect from thrombin-induced BBB breakdown. Pretreatment with DOACs clearly limited the impact of thrombin on PAR-1 cleavage in our model, contrary to other anticoagulants, associated with ZO-1 and VE-cadherin expressions. In conclusion, DOACs seem to limit the alteration of the monolayer of endothelial cells of the BBB mediated by the thrombin/PAR-1 pathway.


Subject(s)
Anticoagulants/pharmacology , Blood-Brain Barrier/drug effects , Thrombin/metabolism , Administration, Oral , Anticoagulants/metabolism , Antigens, CD/metabolism , Cadherins/metabolism , Cell Line , Cerebral Hemorrhage/drug therapy , Endothelial Cells/drug effects , Endothelial Cells/metabolism , Heparin , Humans , Protein Serine-Threonine Kinases/metabolism , Pyrazoles , Pyridones , Receptor, PAR-1/metabolism , Rivaroxaban , Warfarin , Zonula Occludens-1 Protein/metabolism
12.
Int J Pharm ; 551(1-2): 281-289, 2018 Nov 15.
Article in English | MEDLINE | ID: mdl-30240829

ABSTRACT

Endothelial cells are main components of the Blood-Brain Barrier (BBB) and form a tight monolayer that regulates the passage of molecules, with the ATP-Binding Cassette (ABC) transporters efflux pumps. We have developed a human in vitro model of HBEC-5i endothelial cells cultivated alone or with human astrocytes conditioned medium on insert. HBEC-5i cells showed a tight monolayer within 14 days, expressing ZO-1 and claudin 5, a low apparent permeability to small molecules, with a TEER stability during five days. The P-gp, BCRP, MRPs transporters were well expressed and functional. Accumulation and efflux ratio measurement with different ABC transporters substrates (Rhodamine 123, BCECF AM, Hoechst 33342) and inhibitors (verapamil, Ko143, probenecid and cyclosporin A) were conducted. At barrier level, the functionality of ABC transporters was three-fold enhanced in astrocyte conditioned medium. We validated our model by the transport of pharmacological substrates: caffeine, rivaroxaban, and methotrexate. The rivaroxaban and methotrexate were released with an efflux ratio >3 and were decreased by more than half with inhibitors. HBEC-5i model could be used as relevant tool in preclinical studies for assessing the permeability of therapeutic molecules to cross human BBB.


Subject(s)
ATP-Binding Cassette Transporters/metabolism , Blood-Brain Barrier/metabolism , Endothelial Cells/metabolism , Astrocytes , Caffeine/pharmacology , Cell Line , Culture Media, Conditioned , Humans , Methotrexate/pharmacology , Rivaroxaban/pharmacology
13.
Curr Mol Pharmacol ; 11(2): 133-139, 2018.
Article in English | MEDLINE | ID: mdl-27894244

ABSTRACT

BACKGROUND AND OBJECTIVE: The high degree of malignancy of tumour cells is linked to alterations of many physiological parameters like the intracellular pH (pHi). The pHi in cancer cell line is regulated by the carbonic anhydrase IX (CA IX). The main enzymatic function of the CA IX protein is to catalyze the hydration of carbon dioxide into bicarbonate ions and protons. CA IX expression in a broad variety of human tumor tissues is associated with resistance to therapy. One promising approach is to target the mechanism regulating pH homeostasis with carbonic anhydrase inhibitors like sulfamides and coumarins families. METHODS: In this work we have evaluated effects of umbelliferone and acetazolamide in a high resistant melanoma cell line (A375) over expressing CA IX. Impact of effective doses of CA IX inhibitors on apoptosis, intracellular pH (pHi), CA IX protein expression and functionality have been investigated. Determination of effective doses of CA IX inhibitors was performed with MTT tests. We also evaluated sensitization effect of CA inhibitors to conventional therapy as dacarbazin. RESULTS: We have used 10 µM Umbelliferone and 100 µM Acetazolamide as effective doses for 24h. These doses did not induce any apoptosis. Umbelliferone induced a more important pHi decrease than Acetalozamide from 7.3 to 7.08 and to 7.12 respectively, and a more important decrease in s-CA IX fraction showing a decrease in CA IX function. We have demonstrated that pre-treatment with umbelliferone or acetazolamide allows a better dacarbazin efficacy. CONCLUSION: We have demonstrated that inhibitors modify intracellular pH and CAIX functionality and sensitize cells to Dacarbazin. These original results complete the knowledge on Sulfamide CA IX inhibitors, bring new insights about Coumarin compounds and offer new possibilities in high grade melanoma therapies.


Subject(s)
Acetazolamide/pharmacology , Dacarbazine/pharmacology , Intracellular Space/metabolism , Melanoma/pathology , Umbelliferones/pharmacology , Apoptosis/drug effects , Carbonic Anhydrase IX/antagonists & inhibitors , Carbonic Anhydrase IX/metabolism , Carbonic Anhydrase Inhibitors , Cell Line, Tumor , Humans , Hydrogen-Ion Concentration
14.
Cell Physiol Biochem ; 42(4): 1592-1602, 2017.
Article in English | MEDLINE | ID: mdl-28738383

ABSTRACT

BACKGROUND/AIMS: Understanding cellular mechanisms induced by hypoxia is fundamental to reduce blood-brain barrier (BBB) disruption. Nevertheless, the investigation of hypoxia on cellular pathways is complex with true hypoxia because HIF-1α has a short lifetime and rapidly reverts back to a normoxic state. To overcome this difficulty, mimetic agents of the hypoxia pathway have been developed, including the gold standard CoCl2. In this study, we proposed to compare CoCl2 and hydralazine in order to determine a suitable mimetic agent of hypoxia for the study on the BBB. METHODS: We studied the cytotoxicity and the impact of these molecules on the integrity of an in vitro BBB model by comparing them to hypoxia controls. RESULTS: We showed that the impact of hypoxic stress in our in vitro BBB model is rather similar between hydralazine and CoCl2. Chemical hypoxic stress led to an increase of BBB permeability either with CoCl2 or hydralazine. Tight junction protein expressions showed that this chemical hypoxic stress decreased ZO-1 but not occluding expressions, and cells had set up a defence mechanism by increasing expression and activity of their efflux transporters. CONCLUSION: Our results demonstrated that hydralazine is a better mimetic agent and more suitable than CoCl2 because it had the same effect but without the cytotoxic effect on in vitro BBB cells.


Subject(s)
Blood-Brain Barrier/drug effects , Endothelial Cells/drug effects , Hydralazine/pharmacology , Neuroglia/drug effects , Animals , Biological Transport/drug effects , Blood-Brain Barrier/metabolism , Cell Hypoxia/drug effects , Cell Line, Transformed , Cell Line, Tumor , Cell Survival/drug effects , Cobalt/pharmacology , Coculture Techniques , Endothelial Cells/cytology , Endothelial Cells/metabolism , Fluorescein/metabolism , Fluoresceins/metabolism , Fluorescent Dyes/metabolism , Gene Expression Regulation , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Mice , Models, Biological , Neuroglia/cytology , Neuroglia/metabolism , Occludin/genetics , Occludin/metabolism , Permeability/drug effects , Rats , Zonula Occludens-1 Protein/genetics , Zonula Occludens-1 Protein/metabolism
15.
PLoS One ; 11(6): e0158010, 2016.
Article in English | MEDLINE | ID: mdl-27337093

ABSTRACT

Understanding cellular and molecular mechanisms induced by hypoxic stress is crucial to reduce blood-brain barrier (BBB) disruption in some neurological diseases. Since the brain is a complex organ, it makes the interpretation of in vivo data difficult, so BBB studies are often investigated using in vitro models. However, the investigation of hypoxia in cellular pathways is complex with physical hypoxia because HIF-1α (factor induced by hypoxia) has a short half-life. We had set up an innovative and original method of induction of hypoxic stress by hydralazine that was more reproducible, which allowed us to study its impact on an in vitro BBB model. Our results showed that hydralazine, a mimetic agent of the hypoxia pathway, had the same effect as physical hypoxia, with few cytotoxicity effects on our cells. Hypoxic stress led to an increase of BBB permeability which corresponded to an opening of our BBB model. Study of tight junction proteins revealed that this hypoxic stress decreased ZO-1 but not occludin expression. In contrast, cells established a defence mechanism by increasing expression and activity of their efflux transporters (Pgp and MRP-1). This induction method of hypoxic stress by hydralazine is simple, reproducible, controllable and suitable to understand the cellular and molecular mechanisms involved by hypoxia on the BBB.


Subject(s)
Blood-Brain Barrier/drug effects , Blood-Brain Barrier/metabolism , Hydralazine/pharmacology , Hypoxia/metabolism , Membrane Transport Proteins/metabolism , Oxidative Stress/drug effects , Animals , Biological Transport , Biomarkers , Cell Survival/drug effects , Hydralazine/toxicity , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Metabolic Networks and Pathways , Permeability , Rats , Tight Junction Proteins/metabolism
16.
Anticancer Res ; 34(11): 6527-35, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25368255

ABSTRACT

BACKGROUND: The purpose of the present was to investigate whether the in vitro effects of gefitinib, an EGFR tyrosine kinase inhibitor, may regulate the expression of type III sodium phosphate Na/Pi co-transporters in an in vitro glioma model. MATERIALS AND METHODS: Proliferation studies, global native EGFR and phosphorylated EGFR expressions, phosphate transporter type III isoform 1(PiT1) expression and phosphate transport with 99mTc-(V)-DMSA radioligand were performed in G111 (grade II astrocytoma), U-87-MG (grade III astrocytoma) and G152 (grade IV glioblastoma) cells. RESULTS: Cells treated with gefitinib showed a significant decrease in proliferation in relation to EGFR and p-EGFR expression. Gefitinib also produced a decrease in phosphate transport mediated PIT1 expression at both the RNA and protein levels. CONCLUSION: The link between gefitinib acting on the EGFR and PiT1 regulation in these cancer cell lines was herein shown.


Subject(s)
Antineoplastic Agents/pharmacology , ErbB Receptors/metabolism , Glioblastoma/drug therapy , Quinazolines/pharmacology , Sodium-Phosphate Cotransporter Proteins, Type III/antagonists & inhibitors , Apoptosis/drug effects , Blotting, Western , Cell Proliferation/drug effects , Enzyme-Linked Immunosorbent Assay , ErbB Receptors/genetics , Gefitinib , Glioblastoma/metabolism , Glioblastoma/pathology , Humans , Neoplasm Grading , Phosphates/metabolism , Protein Isoforms , RNA, Messenger/genetics , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Sodium-Phosphate Cotransporter Proteins, Type III/genetics , Sodium-Phosphate Cotransporter Proteins, Type III/metabolism , Tumor Cells, Cultured
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