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1.
J Xenobiot ; 14(2): 604-612, 2024 May 07.
Article in English | MEDLINE | ID: mdl-38804288

ABSTRACT

Glyphosate, a widely used herbicide, is linked to a plethora of deleterious effects in both clinical and preclinical studies. Nevertheless, the effects of its main metabolite, aminomethylphosphonic acid (AMPA), whose half-life in soil is even longer than that of glyphosate, have been little explored. On this basis, as a first approach, in this work, we report that intraperitoneal (i.p.) administration of AMPA or glyphosate (at 10, 56, and 100 mg/kg) decreased, to a similar extent, plasma cholinesterase (ChE) activity in acutely exposed rats. Moreover, we designed an experimental protocol to analyze and compare the effects of AMPA and glyphosate on human plasma ChE activity; this protocol consisted of adding these compounds to human plasma to subsequently test the effects of this plasma on the contraction to acetylcholine (ACh) in the frog rectus abdominis muscle (an indirect estimate of ChE activity). Accordingly, this muscular contraction to ACh was evaluated before and after pre-incubation of ACh with (i) plasma alone, (ii) plasma with AMPA, and (iii) plasma with glyphosate. Our results indicate that AMPA, like glyphosate, decreased ChE activity in the plasma of rats (when given i.p.) and humans (when added in vitro), suggesting that both xenobiotics may exert similar toxicological effects.

2.
Drug Chem Toxicol ; : 1-5, 2024 Mar 11.
Article in English | MEDLINE | ID: mdl-38465510

ABSTRACT

It has been reported that glyphosate, one of the most common herbicides used in agriculture, impairs locomotion and cognition. Glyphosate has a variable half-life in soil up to biotic and/or abiotic factors transform the molecule in metabolites such as the aminomethylphosphonic acid (AMPA) that has a longer half-life. In this study, female Sprague Dawley rats were acutely exposed to different doses of glyphosate or AMPA (i.e. 10, 56 or 100 mg/kg) and, subsequently, the acetylcholinesterase (AChE) activity was measured in the hippocampus, prefrontal cortex (PFC) and the gastrocnemius muscle. Both glyphosate and AMPA produced a similar decrease in the AChE activity in all the tissues tested. These results suggest that interference with normal cholinergic neurotransmission may be one of the mechanisms involved in glyphosate-induced motor alterations in rats. Moreover, our results highlight the biological importance of AMPA as a molecule with anticholinesterase action in brain and skeletal muscle. To our knowledge, this is the first report showing in vivo that AMPA, the major metabolite of glyphosate, behaves as an organophosphate.

3.
Environ Toxicol Pharmacol ; 106: 104381, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38311300

ABSTRACT

In recent decades, glyphosate and glyphosate-based herbicides (GBH) have been extensively used in agriculture all over the world. Initially, they were considered safe, but rising evidence suggests that these molecules reach the central nervous system producing metabolic, functional, and permanent alterations that impact cognition and behavior. This theoretical and non-systematic review involved searching, integrating, and analyzing preclinical evidence regarding the effects of acute, sub-chronic, and chronic exposure to glyphosate and GBH on cognition, behavior, neural activity, and development in adult and juvenile rodents following perinatal exposition. In addition, this review gathers the mechanisms underlying the neurotoxicity of glyphosate mediating cognitive and behavioral alterations. Furthermore, clinical evidence of the effects of exposition to GBH on human health and its possible link with several neurological disorders was revised.


Subject(s)
Herbicides , Neurotoxicity Syndromes , Adult , Humans , Female , Pregnancy , Glyphosate , Cognition , Neurotoxicity Syndromes/etiology , Herbicides/toxicity , Agriculture
4.
Metabolites ; 14(1)2024 Jan 13.
Article in English | MEDLINE | ID: mdl-38248853

ABSTRACT

Glyphosate-based herbicides (GBHs) have gained extensive popularity in recent decades. For many years, glyphosate has been regarded as harmless or minimally toxic to mammals due to the absence of its primary target, the shikimic acid pathway in humans. Nonetheless, mounting evidence suggests that glyphosate may cause adverse health effects in humans via other mechanisms. In this study, we described the metabolomic changes in the serum of experimental rats exposed to chronic GBH using the highly sensitive LC-MS/MS technique. We investigated the possible relationship between chronic exposure to GBH and neurological disorders. Our findings suggest that chronic exposure to GBH can alter spatial learning memory and the expression of some important metabolites that are linked to neurophysiological disorders in young rats, with the female rats showing higher susceptibility compared to the males. This indicates that female rats are more likely to show early symptoms of the disorder on exposure to chronic GBH compared to male rats. We observed that four important metabolites (paraxanthine, epinephrine, L-(+)-arginine, and D-arginine) showed significant changes and involvement in neurological changes as suggested by ingenuity pathway analysis. In conclusion, our results indicate that chronic exposure to GBH can increase the risk of developing neurological disorders.

5.
Rev Iberoam Micol ; 39(2): 36-43, 2022.
Article in English | MEDLINE | ID: mdl-35738989

ABSTRACT

BACKGROUND: Staphylococcus aureus and Candida albicans have been co-isolated from biofilm-associated diseases such as denture stomatitis, periodontitis, and burn wound infections, as well as from medical devices. However, the polymicrobial biofilm of both microorganisms has not been fully characterized. AIMS: To characterize the polymicrobial biofilm of C. albicans and S. aureus in terms of microbial density, synergy, composition, structure, and stability against antimicrobials and chemical agents. METHODS: Crystal violet assay was used to measure the biofilm formation. Scanning electron microscopy and confocal microscopy were used to analyze the structure and chemical composition of the biofilms, respectively. RESULTS: Supplemented media with fetal bovine serum (FBS) decreased the biofilm formation of S. aureus and the polymicrobial biofilm. For C. albicans, depending on the culture media, the addition of glucose or FBS had a positive effect in biofilm formation. FBS decreased the adhesion to polystyrene wells for both microorganisms. Supplementing the media with glucose and FBS enhanced the growth of C. albicans and S. aureus, respectively. It seems that C. albicans contributes the most to the adhesion process and to the general structure of the biofilms on all the surfaces tested, including a catheter model. Interestingly, S. aureus showed a great adhesion capacity to the surface of C. albicans in the biofilms. Proteins and ß-1,6-linked polysaccharides seem to be the most important molecules in the polymicrobial biofilm. CONCLUSIONS: The polymicrobial biofilm had a complex structure, with C. albicans serving as a scaffold where S. aureus adheres, preferentially to the hyphal form of the fungus. Detection of polymicrobial infections and characterization of biofilms will be necessary in the future to provide a better treatment.


Subject(s)
Anti-Infective Agents , Candida albicans , Biofilms , Glucose/metabolism , Glucose/pharmacology , Staphylococcus aureus
6.
Rev. iberoam. micol ; 39(2): 36-43, abril 2022. graf, tab
Article in English | IBECS | ID: ibc-207100

ABSTRACT

Background:Staphylococcus aureus and Candida albicans have been co-isolated from biofilm-associated diseases such as denture stomatitis, periodontitis, and burn wound infections, as well as from medical devices. However, the polymicrobial biofilm of both microorganisms has not been fully characterized.Aims:To characterize the polymicrobial biofilm of C. albicans and S. aureus in terms of microbial density, synergy, composition, structure, and stability against antimicrobials and chemical agents.Methods:Crystal violet assay was used to measure the biofilm formation. Scanning electron microscopy and confocal microscopy were used to analyze the structure and chemical composition of the biofilms, respectively.Results:Supplemented media with fetal bovine serum (FBS) decreased the biofilm formation of S. aureus and the polymicrobial biofilm. For C. albicans, depending on the culture media, the addition of glucose or FBS had a positive effect in biofilm formation. FBS decreased the adhesion to polystyrene wells for both microorganisms. Supplementing the media with glucose and FBS enhanced the growth of C. albicans and S. aureus, respectively. It seems that C. albicans contributes the most to the adhesion process and to the general structure of the biofilms on all the surfaces tested, including a catheter model. Interestingly, S. aureus showed a great adhesion capacity to the surface of C. albicans in the biofilms. Proteins and β-1,6-linked polysaccharides seem to be the most important molecules in the polymicrobial biofilm. (AU)


Antecedentes:Staphylococcus aureus y Candida albicans son aislados conjuntamente de infecciones asociadas a la formación de biopelículas, tales como periodontitis, estomatitis e infecciones provenientes de quemaduras, así como en dispositivos médicos. Sin embargo, la biopelícula formada por ambos microorganismos no ha sido completamente caracterizada.Objetivos:Caracterizar la biopelícula de C. albicans y S. aureus en cuanto a densidad microbiana, sinergismo, composición, estructura y estabilidad frente a agentes químicos y antimicrobianos.Métodos:El análisis de la formación de biopelícula se realizó mediante el ensayo de cristal violeta. Se analizó la composición química y la estructura de las biopelículas mediante microscopio confocal y microscopio electrónico de barrido, respectivamente.Resultados:La adición al medio de suero bovino fetal (SBF) redujo la biopelícula mono- y polimicrobiana de S. aureus. En C. albicans, con la adición de glucosa o SBF, se incrementó la formación de biopelícula. La adhesión de los microorganismos a las placas de poliestireno se redujo en presencia de SBF. La suplementación del medio con glucosa y SBF favoreció la proliferación de C. albicans y S. aureus, respectivamente. C. albicans mostró una mejor adhesión y contribuyó más a la densidad total de la biopelícula en diferentes superficies probadas, incluyendo un modelo de catéter. De manera interesante, S. aureus mostró una mejor adhesión a la superficie de C. albicans en la biopelícula. Las proteínas y los polisacáridos con enlaces β-1,6 parecen ser las moléculas más abundantes en la biopelícula. (AU)


Subject(s)
Humans , Anti-Infective Agents , Biofilms , Candida albicans , Glucose/metabolism , Glucose/pharmacology
7.
Vet Rec Open ; 8(1): e20, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34631111

ABSTRACT

BACKGROUND: Actinobacillus pleuropneumoniae (AP) is the causative agent of porcine pleuropneumonia. Apx exotoxins are the most important virulence factors associated with the induction of lesions. ApxI is highly cytotoxic on a wide range of cells. Besides the induction of necrosis and apoptosis of ApxI on porcine alveolar macrophages (PAMs), its role in pyroptosis, a caspase-1-dependent form of cell death, has not been reported. The aim of this study was to analyse if NLRP3 inflammasome participates in cell death induced by ApxI. METHODS: PAMs, the porcine alveolar macrophage cell line 3D4/21 and a porcine aortic endothelial cell line were used in this study. We used Z-VAD-FMK and Ac-YVAD-cmk to inhibit caspase-1. Glyburide and MCC950 were used to inhibit the NLRP3 inflammasome. A lactate dehydrogenase release assay was used to measure the percentage of cell death. Caspase-1 expression was analysed by immunofluorescence. End-point RT-PCR was used to analyse the expression of NLRP3 mRNA. RESULTS: Rapid cell death in PAMs, 3D4/21 cells and the endothelial cell line were induced by ApxI. This cell death decreased by using caspase-1 and NLRP3 inflammasome inhibitors and by blocking the K+ efflux. Expression of NLRP3 mRNA was induced by ApxI in alveolar macrophages while it was constitutive in the endothelial cell line. Detection of caspase-1 in alveolar macrophages was higher after ApxI treatment and it was blocked by MCC950 or heat inactivation. CONCLUSIONS: To the best of the authors' knowledge, we have described for the first time in vitro induction of ApxI associated pyroptosis in alveolar macrophages and endothelial cells, a rapid cell death that depends on the activation of caspase-1 via the NLRP3 inflammasome.

8.
Biomedicines ; 9(9)2021 Sep 04.
Article in English | MEDLINE | ID: mdl-34572344

ABSTRACT

Hepatocellular carcinoma has become a leading cause of cancer-associated mortality throughout the world, and is of great concern. Currently used chemotherapeutic drugs in the treatment of hepatocellular carcinoma lead to severe side effects, thus underscoring the need for further research to develop novel and safer therapies. Liver resection in cancer patients is routinely performed. After partial resection, liver regeneration is a perfectly calibrated response apparently sensed by the body's required liver function. This process hinges on the effect of several growth factors, among other molecules. However, dysregulation of growth factor signals also leads to growth signaling autonomy and tumor progression, so control of growth factor expression may prevent tumor progression. This review describes the role of some of the main growth factors whose dysregulation promotes liver tumor progression, and are also key in regenerating the remaining liver following resection. We herein summarize and discuss studies focused on partial hepatectomy and liver carcinogenesis, referring to hepatocyte growth factor, insulin-like growth factor, and epidermal growth factor, as well as their suitability as targets in the treatment of hepatocellular carcinoma. Finally, and given that drugs remain one of the mainstay treatment options in liver carcinogenesis, we have reviewed the current pharmacological approaches approved for clinical use or research targeting these factors.

9.
Neurosci Bull ; 37(10): 1493-1509, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34302618

ABSTRACT

The periaqueductal gray (PAG) is a complex mesencephalic structure involved in the integration and execution of active and passive self-protective behaviors against imminent threats, such as immobility or flight from a predator. PAG activity is also associated with the integration of responses against physical discomfort (e.g., anxiety, fear, pain, and disgust) which occurs prior an imminent attack, but also during withdrawal from drugs such as morphine and cocaine. The PAG sends and receives projections to and from other well-documented nuclei linked to the phenomenon of drug addiction including: (i) the ventral tegmental area; (ii) extended amygdala; (iii) medial prefrontal cortex; (iv) pontine nucleus; (v) bed nucleus of the stria terminalis; and (vi) hypothalamus. Preclinical models have suggested that the PAG contributes to the modulation of anxiety, fear, and nociception (all of which may produce physical discomfort) linked with chronic exposure to drugs of abuse. Withdrawal produced by the major pharmacological classes of drugs of abuse is mediated through actions that include participation of the PAG. In support of this, there is evidence of functional, pharmacological, molecular. And/or genetic alterations in the PAG during the impulsive/compulsive intake or withdrawal from a drug. Due to its small size, it is difficult to assess the anatomical participation of the PAG when using classical neuroimaging techniques, so its physiopathology in drug addiction has been underestimated and poorly documented. In this theoretical review, we discuss the involvement of the PAG in drug addiction mainly via its role as an integrator of responses to the physical discomfort associated with drug withdrawal.


Subject(s)
Periaqueductal Gray , Substance-Related Disorders , Amygdala , Humans , Morphine , Nociception
10.
Pharmacology ; 106(5-6): 305-315, 2021.
Article in English | MEDLINE | ID: mdl-33756489

ABSTRACT

BACKGROUND: Piperidines are biogenic amines studied mainly in toxicology because they were initially found as alkaloids from peppers and insect venoms. Piperidines are also produced in the human body, and their actions seem to be related to wakefulness/sleep and other cognitive phenomena. Piperidines have been minimally characterized for therapeutic applications. In this context, 1-Boc-piperidine-4-carboxaldehyde (1-Boc-piperidine) is a piperidine-derivative molecule with no mechanism of action reported, although its uses include the synthesis of GPR119 selective agonists that have been patented as anti-obesity drugs. OBJECTIVES: The aim of this work was to study the effects of 1-Boc-piperidine on binge-eating behaviour and anxiety in Wistar rats. METHODS: In experimental protocol 1, binge-eating behaviour was induced in animals that received pre-treatment (i.p.) with (i) vehicle (methanol 10%; 1 mL/kg), (ii) 1-Boc-piperidine (1 µmol kg-1), or (iii) 1-Boc-piperidine (10 µmol kg-1). In experimental protocol 2, mildly stressed animals were evaluated in the elevated plus maze under the acute effects of the pre-treatments applied in experimental protocol 1. RESULTS AND CONCLUSIONS: 1-Boc-piperidine decreased, in a dose-dependent manner, the intake of calories from a succulent hyper-caloric food in a binge-eating protocol in female rats, whereas the acute exposition to this piperidine exerted an anxiolytic effect in the male rat. In both effects, the mechanism of action remains to be characterized.


Subject(s)
Anxiety/drug therapy , Binge-Eating Disorder/drug therapy , Animals , Anxiety/etiology , Behavior, Animal/drug effects , Binge-Eating Disorder/etiology , Dose-Response Relationship, Drug , Energy Intake/drug effects , Feeding Behavior/drug effects , Injections, Intraperitoneal , Ligands , Molecular Docking Simulation , Molecular Dynamics Simulation , Pain/complications , Protein Binding , Rats, Wistar , Receptors, G-Protein-Coupled/chemistry , Receptors, G-Protein-Coupled/metabolism , Receptors, Serotonin/chemistry , Receptors, Serotonin/metabolism , Stress, Psychological/complications , Weight Gain/drug effects
11.
Front Public Health ; 9: 559595, 2021.
Article in English | MEDLINE | ID: mdl-33665182

ABSTRACT

Uncontrolled diabetes results in several metabolic alterations including hyperglycemia. Indeed, several preclinical and clinical studies have suggested that this condition may induce susceptibility and the development of more aggressive infectious diseases, especially those caused by some bacteria (including Chlamydophila pneumoniae, Haemophilus influenzae, and Streptococcus pneumoniae, among others) and viruses [such as coronavirus 2 (CoV2), Influenza A virus, Hepatitis B, etc.]. Although the precise mechanisms that link glycemia to the exacerbated infections remain elusive, hyperglycemia is known to induce a wide array of changes in the immune system activity, including alterations in: (i) the microenvironment of immune cells (e.g., pH, blood viscosity and other biochemical parameters); (ii) the supply of energy to infectious bacteria; (iii) the inflammatory response; and (iv) oxidative stress as a result of bacterial proliferative metabolism. Consistent with this evidence, some bacterial infections are typical (and/or have a worse prognosis) in patients with hypercaloric diets and a stressful lifestyle (conditions that promote hyperglycemic episodes). On this basis, the present review is particularly focused on: (i) the role of diabetes in the development of some bacterial and viral infections by analyzing preclinical and clinical findings; (ii) discussing the possible mechanisms by which hyperglycemia may increase the susceptibility for developing infections; and (iii) further understanding the impact of hyperglycemia on the immune system.


Subject(s)
Bacterial Infections/etiology , COVID-19/etiology , Diabetes Complications/immunology , Diabetes Complications/physiopathology , Disease Susceptibility , Hyperglycemia/complications , Virus Diseases/etiology , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged
12.
Pharmacol Biochem Behav ; 199: 173071, 2020 12.
Article in English | MEDLINE | ID: mdl-33171140

ABSTRACT

Neuropeptide Y (NPY) is likely the main endogenous anxiolytic neuromodulator involved in alcohol intake. NPY-Y1, a receptor for NPY, is highly expressed in the periaqueductal gray (PAG), a mesencephalic structure involved in integrating nervous activity to the performance of active and passive defensive behaviors related to fear and anxiety. Interestingly, anxiety and fear are some of the prevailing emotional negative states during alcohol abstinence. Moreover, an inverse relationship between NPY activity and alcohol consumption has been frequently reported, mainly in the extended amygdala. Nevertheless, both the roles of NPY and that of the receptor involved in these actions have been scarcely studied. Thus, the aim of this study was to analyze the pharmacological effect of NPY and NPY-Y1 receptor blockade into the dorsal periaqueductal gray (D-PAG) in an alcohol consumption and relapse paradigm in adult male Wistar rats. Ninety-six rats at postnatal day 42 (PND-42) were classified as having low and high anxiety (LA and HA), respectively, through the elevated plus maze test (EPM). Then, those animals were randomly divided into alcohol naïve (AN) and forced alcohol consumption (FAC) groups. A cannula was implanted in D-PAG to microinject vehicle (VEH), NPY, or BIBP-3226 (a selective NPY-Y1 receptor antagonist). A defensive burying behavior test (DBB) was performed to assess the anxiety-like state during withdrawal, followed by a 24-hour free choice voluntary alcohol intake test. Under our experimental conditions, NPY microinjection decreased alcohol consumption in HA rats, whereas NPY-Y1 receptor blockade in D-PAG produced a notably anxiogenic effect and higher alcohol intake and relapse. In conclusion, NPY in the D-PAG, most likely acting on NPY-Y1 receptors, induced a significant anxiolytic effect and prominently inhibited alcohol consumption and relapse in Wistar rats.


Subject(s)
Alcohol Drinking/physiopathology , Anxiety/physiopathology , Ethanol/administration & dosage , Ethanol/pharmacology , Receptors, Neuropeptide Y/physiology , Animals , Anti-Anxiety Agents/administration & dosage , Arginine/administration & dosage , Arginine/analogs & derivatives , Male , Maze Learning , Microinjections , Periaqueductal Gray/physiology , Rats , Rats, Wistar , Receptors, Neuropeptide Y/antagonists & inhibitors , Recurrence
13.
Front Pharmacol ; 11: 628, 2020.
Article in English | MEDLINE | ID: mdl-32457622

ABSTRACT

GPR12 is a G protein-coupled orphan receptor genetically related to type 1 and type 2 cannabinoid receptors (CB1 and CB2) which are ancient proteins expressed all over the body. Both cannabinoid receptors, but especially CB1, are involved in neurodevelopment and cognitive processes such as learning, memory, brain reward, coordination, etc. GPR12 shares with CB1 that both are mainly expressed into the brain. Regrettably, very little is known about physiology of GPR12. Concerning its pharmacology, GPR12 seems to be endogenously activated by the lysophospholipids sphingosine-1-phosphate (S1P) and sphingosyl-phosphorylcholine (SPC). Exogenously, GPR12 is a target for the phytocannabinoid cannabidiol (CBD). Functionally, GPR12 seems to be related to neurogenesis and neural inflammation, but its relationship with cognitive functions remains to be characterized. Although GPR12 was initially suggested to be a cannabinoid receptor, it does not meet the five criteria proposed in 2010 by the International Union of Basic and Clinical Pharmacology (IUPHAR). In this review, we analyze all the direct available information in PubMed database about expression, function, and pharmacology of this receptor in central nervous system (CNS) trying to provide a broad overview of its current and prospective neurophysiology. Moreover, in this mini-review we highlight the need to produce more relevant data about the functions of GPR12 in CNS. Hence, this work should motivate further research in this field.

14.
Cell Calcium ; 65: 80-90, 2017 07.
Article in English | MEDLINE | ID: mdl-28249687

ABSTRACT

It has been shown that 2-APB is a nonspecific modulator of ion channel activity, while most of the channels are inhibited by this compound, there are few examples of channels that are activated by 2-APB. Additionally, it has been shown that, 2-APB leads to a reduction in the luminal endoplasmic reticulum Ca2+ level ([Ca2+]ER) and we have carried out simultaneous recordings of both [Ca2+]i and the [Ca2+]ER in HeLa cell suspensions to assess the mechanism involved in this effect. This approach allowed us to determine that 2-APB induces a reduction in the [Ca2+]ER by activating an ER-resident Ca2+ permeable channel more than by inhibiting the activity of SERCA pumps. Interestingly, this effect of 2-APB of reducing the [Ca2+]ER is auto-limited because depends on a replete ER Ca2+ store; a condition that thapsigargin does not require to decrease the [Ca2+]ER. Additionally, our data indicate that the ER Ca2+ permeable channel activated by 2-APB does not seem to participate in the ER Ca2+ leak revealed by inhibiting SERCA pump with thapsigargin. This work suggests that, prolonged incubations with even low concentrations of 2-APB (5µM) would lead to the reduction in the [Ca2+]ER that might explain the inhibitory effect of this compound on those signals that require Ca2+ release from the ER store.


Subject(s)
Boron Compounds/pharmacology , Calcium Signaling/drug effects , Calcium/metabolism , Endoplasmic Reticulum/metabolism , Sarcoplasmic Reticulum Calcium-Transporting ATPases/antagonists & inhibitors , HeLa Cells , Humans , Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism , Thapsigargin/pharmacology
15.
Cell Calcium ; 65: 91-101, 2017 07.
Article in English | MEDLINE | ID: mdl-28179072

ABSTRACT

We have studied in HeLa cells the molecular nature of the 2-APB induced ER Ca2+ leak using synthetic Ca2+ indicators that report changes in both the cytoplasmic ([Ca2+]i) and the luminal ER ([Ca2+]ER) Ca2+ concentrations. We have tested the hypothesis that Orai channels participate in the 2-APB-induced ER Ca2+ leak that was characterized in the companion paper. The expression of the dominant negative Orai1 E106A mutant, which has been reported to block the activity of all three types of Orai channels, inhibited the effect of 2-APB on the [Ca2+]ER but did not decrease the ER Ca2+ leak after thapsigargin (TG). Orai3 channel, but neither Orai1 nor Orai2, colocalizes with expressed IP3R and only Orai3 channel supported the 2-APB-induced ER Ca2+ leak, while Orai1 and Orai2 inhibited this type of ER Ca2+ leak. Decreasing the expression of Orai3 inhibited the 2-APB-induced ER Ca2+ leak but did not modify the ER Ca2+ leak revealed by inhibition of SERCA pumps with TG. However, reducing the expression of Orai3 channel resulted in larger [Ca2+]i response after TG but only when the ER store had been overloaded with Ca2+ by eliminating the acidic internal Ca2+ store with bafilomycin. These data suggest that Orai3 channel does not participate in the TG-revealed ER Ca2+ leak but forms an ER Ca2+ leak channel that is limiting the overloading with Ca2+ of the ER store.


Subject(s)
Boron Compounds/pharmacology , Calcium Channels/metabolism , Calcium Signaling/drug effects , Calcium/metabolism , Endoplasmic Reticulum/metabolism , HeLa Cells , Humans , Inositol 1,4,5-Trisphosphate Receptors/metabolism , Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism , Thapsigargin/pharmacology
16.
Cell Signal ; 28(1): 53-9, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26475209

ABSTRACT

Palmitic acid is a negative regulator of insulin activity. At the molecular level, palmitic acid reduces insulin stimulated Akt Ser473 phosphorylation. Interestingly, we have found that incubation with palmitic acid of human umbilical vein endothelial cells induced a biphasic effect, an initial transient elevation followed by a sustained reduction of SERCA pump protein levels. However, palmitic acid produced a sustained inhibition of SERCA pump ATPase activity. Insulin resistance state appeared before there was a significant reduction of SERCA2 expression. The mechanism by which palmitic acid impairs insulin signaling may involve endoplasmic reticulum stress, because this fatty acid induced activation of both PERK, an ER stress marker, and JNK, a kinase associated with insulin resistance. None of these effects were observed by incubating HUVEC-CS cells with palmitoleic acid. Importantly, SERCA2 overexpression decreased the palmitic acid-induced insulin resistance state. All these results suggest that SERCA pump might be the target of palmitic acid to induce the insulin resistance state in a human vascular endothelial cell line. Importantly, these data suggest that HUVEC-CS cells respond to palmitic acid-exposure with a compensatory overexpression of SERCA pump within the first hour, which eventually fades out and insulin resistance prevails.


Subject(s)
Endoplasmic Reticulum Stress/drug effects , Endothelial Cells/drug effects , Fatty Acids, Monounsaturated/pharmacology , Insulin Resistance/physiology , Palmitic Acid/pharmacology , Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism , Apoptosis/drug effects , Cell Line , Endoplasmic Reticulum/metabolism , Endothelial Cells/metabolism , Humans
17.
Cell Calcium ; 56(5): 311-22, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25239386

ABSTRACT

The endoplasmic reticulum is the main intracellular Ca(2+) store for Ca(2+) release during cell signaling. There are different strategies to avoid ER Ca(2+) depletion. Release channels utilize first Ca(2+)-bound to proteins and this minimizes the reduction of the free luminal [Ca(2+)]. However, if release channels stay open after exhaustion of Ca(2+)-bound to proteins, then the reduction of the free luminal ER [Ca(2+)] (via STIM proteins) activates Ca(2+) entry at the plasma membrane to restore the ER Ca(2+) load, which will work provided that SERCA pump is active. Nevertheless, there are several noxious conditions that result in decreased activity of the SERCA pump such as oxidative stress, inflammatory cytokines, and saturated fatty acids, among others. These conditions result in a deficient restoration of the ER [Ca(2+)] and lead to the ER stress response that should facilitate recovery of the ER. However, if the stressful condition persists then ER stress ends up triggering cell death and the ensuing degenerative process leads to diverse pathologies; particularly insulin resistance, diabetes and several of the complications associated with diabetes. This scenario suggests that limiting ER stress should decrease the incidence of diabetes and the mobility and mortality associated with this illness.


Subject(s)
Calcium/metabolism , Diabetes Mellitus/genetics , Endoplasmic Reticulum Stress/genetics , Insulin Resistance/genetics , Calcium Signaling/genetics , Diabetes Mellitus/pathology , Endoplasmic Reticulum/metabolism , Endoplasmic Reticulum/pathology , Endothelial Cells/metabolism , Endothelial Cells/pathology , Humans , Sarcoplasmic Reticulum Calcium-Transporting ATPases/genetics , Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism
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