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1.
J Pak Med Assoc ; 72(11): 2170-2174, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37013280

RESUMO

OBJECTIVE: To investigate the effect of a novel mineral containing toothpaste in comparison to a fluoride toothpaste in children with white spot lesions. METHODS: The clinical study was conducted from 2016 to 2018 at Marmara University Department of Pediatric Dentistry Clinic after approval from the ethics review committee of Yeditepe University, Istanbul, Turkey and comprised children of either gender aged 4-5 years having white spot lesions. They were randomly allocated into two groups. The FT (Fluoridated Toothpaste) group was given a 500ppm fluoridated toothpaste, while the Mineral Containing Toothpaste (MCT) group was given toothpaste containing calcium glycerophosphate, magnesium chloride, and 12% xylitol. The white spot lesions were examined using Laser Fluorescence (LF) at baseline and after a month of usage. The two readings were compared. Stimulated saliva was collected for measuring the salivary potential of hydrogen, buffering capacity, and streptococcus mutans. Data was analysed using SPSS 19. RESULTS: Of the 26 children, 10(38%) were girls and 16(62%) were boys. The overall mean age was 4.77±0.54 years. There were 13(50%) subjects in each of the two groups. Of the 381 measurements done, 198(52%) were in the MCT group and 183(48%) in the FT group. LF scores decreased in both the groups (p=0.001). The remineralising potential was not significantly different (p=0.866), while salivary buffering capacity and potential of hydrogen increased in both the groups but the change was not significant (p>0.05). The number of children positive for streptococcus mutans decreased in both the groups (p>0.05). CONCLUSIONS: The toothpaste containing calcium glycerophosphate, magnesium chloride and 12% xylitol had the remineralization properties needed for the prevention of gwhite spot lesions in children.


Assuntos
Cariostáticos , Cárie Dentária , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Cariostáticos/uso terapêutico , Cárie Dentária/prevenção & controle , Cárie Dentária/tratamento farmacológico , Fluoretos/uso terapêutico , Glicerofosfatos/farmacologia , Cloreto de Magnésio/farmacologia , Minerais/farmacologia , Streptococcus mutans , Cremes Dentais/uso terapêutico , Cremes Dentais/farmacologia , Xilitol/farmacologia
2.
J Diet Suppl ; 19(4): 483-498, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33749469

RESUMO

Magnesium supplementation may be beneficial for cancer patients due to its action as a modulator of cell proliferation and metabolism and its anti-inflammatory effect. Tumor metabolism can influence the bioavailability and absorption of nutrients, leading to an increase in the individual's nutritional needs. In this work, the effects of supplementing different dosages of magnesium chloride in mice with solid Ehrlich's tumors were investigated by analyzing their hematological, inflammatory and anthropometric biomarkers. Three dosages of magnesium chloride (MgCl2) were administered for 28 consecutive days. Animal welfare was assessed according to the criteria stipulated by the National Center for the Replacement, Refinement, and Reduction of Animals in Research (NC3Rs). The inverted grid method was used to analyze muscle strength and fatigue. Difference in expression of the Tumor Necrosis Factor (TNF-α) and the Growth Transformation Factor (TGF-ß1) genes was determined by the 2-ΔCt method. The hematological evaluation consisted of the erythrogram, white blood cell and platelet counts were used for the hematological evaluation and treatment cytotoxicity. Difference in the expression of the TNF-α and TGF-ß genes showed that the group that received a high dose of magnesium had a decrease in TNF-α and RNL, an improvement in well-being with a tendency to increase muscle strength and less tumor progression according to the days of treatment. The group that received a low dosage of magnesium had a smaller tumor volume and a more controlled tumor growth according to the days. The group that received an intermediate dosage presented cytotoxicity.


Assuntos
Cloreto de Magnésio , Neoplasias , Animais , Suplementos Nutricionais , Inflamação/tratamento farmacológico , Cloreto de Magnésio/farmacologia , Camundongos , Neoplasias/tratamento farmacológico , Neoplasias/genética , Fator de Necrose Tumoral alfa
3.
Eur J Histochem ; 65(s1)2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34755507

RESUMO

Oxaliplatin is a third-generation chemotherapy drug mainly used for colorectal cancer treatment. However, it is also known to trigger neuropathy whose underlying neurobiological mechanisms are still under investigation and currently available treatments show limited efficacy. It is now established that neurons are not the only cell type involved in chronic pain and that glial cells, mainly astrocytes and microglia, are involved in the initiation and maintenance of neuropathy. Among all the pathogenetic factors involved in neuropathic pain, an oxaliplatin-dependent oxidative stress plays a predominant role. In our study, the antioxidant properties of magnesium (Mg), manganese (Mn) and zinc (Zn) salts were evaluated in order to counteract microglial activation induced by oxaliplatin. The antioxidant efficacy of these metals was evaluated by the means of molecular and morphological assays on the BV-2 microglial cell line. Our data clearly show that Mg, Mn and Zn are able to prevent oxaliplatin-dependent microglial alterations by reducing both oxidative and endoplasmic reticulum stress.


Assuntos
Antioxidantes/farmacologia , Cloretos/farmacologia , Cloreto de Magnésio/farmacologia , Compostos de Manganês/farmacologia , Oxaliplatina/toxicidade , Compostos de Zinco/farmacologia , Animais , Antígeno B7-2/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Linhagem Celular , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Camundongos , Proteínas dos Microfilamentos/metabolismo , Microglia/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
4.
Reprod Biomed Online ; 43(6): 1079-1086, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34753679

RESUMO

RESEARCH QUESTION: What is the mechanism by which human follicular fluid inhibits seminal plasma DNase activity? DESIGN: Human genomic DNA was incubated with human follicular fluid and seminal plasma (reaction mixture) under different experimental conditions; increasing volumes of human follicular fluid; proteinase K digested or heat inactivated human follicular fluid; and the addition of Ca2+ or Mg2+ to the reaction mixture. RESULTS: Increasing volume of human follicular fluid resulted in a dose-dependent inhibition of seminal plasma DNase activity. Inhibition was not caused by proteins in the human follicular fluid as digestion with proteinase K or heat inactivation of human follicular fluid failed to abolish its inhibitory effect. Addition of divalent cations resulted in a reversion of the inhibitory effect, providing evidence that human follicular fluid inhibition of seminal plasma DNase activity seems to be mediated by a compound with chelating activity. Furthermore, incubation of genomic DNA with human follicular fluid in the presence of divalent cations served to elicit the existence of DNase activity. CONCLUSIONS: Human follicular fluid seems to contain a molecule or molecules with chelating capacity that inhibits DNase activity of both follicular fluid and seminal plasma. Our findings provide new insight to understanding sperm preservation and the physiology of fertilization biology.


Assuntos
Quelantes/farmacologia , Desoxirribonucleases/metabolismo , Líquido Folicular/metabolismo , Sêmen/metabolismo , Cloreto de Cálcio/farmacologia , Feminino , Humanos , Cloreto de Magnésio/farmacologia , Masculino , Sêmen/efeitos dos fármacos , Preservação do Sêmen/métodos
5.
Int J Mol Sci ; 22(19)2021 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-34639202

RESUMO

The interactions of ligands with nucleic acids are central to numerous reactions in the biological cell. How such reactions are affected by harsh environmental conditions such as low temperatures, high pressures, and high concentrations of destructive ions is still largely unknown. To elucidate the ions' role in shaping habitability in extraterrestrial environments and the deep subsurface of Earth with respect to fundamental biochemical processes, we investigated the effect of selected salts (MgCl2, MgSO4, and Mg(ClO4)2) and high hydrostatic pressure (relevant for the subsurface of that planet) on the complex formation between tRNA and the ligand ThT. The results show that Mg2+ salts reduce the binding tendency of ThT to tRNA. This effect is largely due to the interaction of ThT with the salt anions, which leads to a strong decrease in the activity of the ligand. However, at mM concentrations, binding is still favored. The ions alter the thermodynamics of binding, rendering complex formation that is more entropy driven. Remarkably, the pressure favors ligand binding regardless of the type of salt. Although the binding constant is reduced, the harsh conditions in the subsurface of Earth, Mars, and icy moons do not necessarily preclude nucleic acid-ligand interactions of the type studied here.


Assuntos
Benzotiazóis/metabolismo , Cloreto de Magnésio/farmacologia , Sulfato de Magnésio/farmacologia , Percloratos/farmacologia , Pressão , RNA de Transferência/metabolismo , Temperatura , Benzotiazóis/química , Planeta Terra , Exobiologia , Meio Ambiente Extraterreno , Ligantes , Marte , Lua , RNA de Transferência/química , Termodinâmica
6.
Int J Mol Sci ; 22(18)2021 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-34576237

RESUMO

Previous studies reported on the broad-spectrum antiviral function of heparin. Here we investigated the antiviral function of magnesium-modified heparin and found that modified heparin displayed a significantly enhanced antiviral function against human adenovirus (HAdV) in immortalized and primary cells. Nuclear magnetic resonance analyses revealed a conformational change of heparin when complexed with magnesium. To broadly explore this discovery, we tested the antiviral function of modified heparin against herpes simplex virus type 1 (HSV-1) and found that the replication of HSV-1 was even further decreased compared to aciclovir. Moreover, we investigated the antiviral effect against the new severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) and measured a 55-fold decreased viral load in the supernatant of infected cells associated with a 38-fold decrease in virus growth. The advantage of our modified heparin is an increased antiviral effect compared to regular heparin.


Assuntos
Antivirais/farmacologia , Heparina/farmacologia , Cloreto de Magnésio/farmacologia , Aciclovir/farmacologia , Adenovírus Humanos/efeitos dos fármacos , Adenovírus Humanos/fisiologia , Animais , Antivirais/química , Células CHO , Linhagem Celular Tumoral , Chlorocebus aethiops , Cricetulus , Avaliação Pré-Clínica de Medicamentos , Fibroblastos , Heparina/química , Herpesvirus Humano 1/efeitos dos fármacos , Herpesvirus Humano 1/fisiologia , Humanos , Cloreto de Magnésio/química , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Estrutura Molecular , Cultura Primária de Células , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/fisiologia , Relação Estrutura-Atividade , Células Vero , Carga Viral/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos
7.
Metabolomics ; 17(8): 73, 2021 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-34390406

RESUMO

BACKGROUND: The New Zealand Green-lipped mussel industry is well-established providing vastly to aquaculture exports. To assess mussel health and reproduction status, visual examination of organs and/or collection of haemolymph is commonly applied. Anesthetics, such as magnesium chloride (MgCl2) can be utilized to prevent muscle contraction and keep shells open during sampling. The specific effects of muscle relaxing agents on baseline metabolism in invertebrates is unknown, but it is evident that molecular, cellular and physiological parameters are altered with these chemical applications. To this end, metabolomics approaches can help elucidate the effects of relaxing agents for better assessment of their use as a research tool. METHODS: Adult Green-lipped mussels were anaesthetized for 3 h in a MgCl2 bath, whereafter haemolymph samples were collected and analyzed via gas chromatography-mass spectrometry applying methyl chloroformate alkylation derivatization. RESULTS: Anesthetized mussels were characterized as non-responsive to manual manipulation, with open valves, and limited siphoning function. Metabolite profiling revealed significant increases in the abundances of most metabolites with an array of metabolic activities affected, resulting in an energy imbalance driven by anaerobic metabolism with altered amino acids acting as neurotransmitters and osmolytes. CONCLUSION: This research is the first to use a metabolomics approach to identify the metabolic consequences of this commonly used bivalve relaxing technique. Ultimately the use of MgCl2 anesthetization as a sampling strategy should be carefully evaluated and managed when performing metabolomics-related research.


Assuntos
Bloqueadores dos Canais de Cálcio , Hemolinfa , Cloreto de Magnésio , Metaboloma , Perna (Organismo) , Anestesia/métodos , Anestesia/veterinária , Anestésicos/farmacologia , Animais , Bloqueadores dos Canais de Cálcio/farmacologia , Cromatografia Gasosa-Espectrometria de Massas/veterinária , Hemolinfa/química , Hemolinfa/metabolismo , Cloreto de Magnésio/farmacologia , Metaboloma/efeitos dos fármacos , Fármacos Neuromusculares/farmacologia , Perna (Organismo)/efeitos dos fármacos , Perna (Organismo)/metabolismo
8.
Behav Brain Res ; 413: 113460, 2021 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-34252502

RESUMO

Evidence suggest that magnesium dietary supplementation has several health benefits including lowering blood pressure, reducing insulin resistance, and improving symptoms of depression, anxiety, and migraine. Here, we aimed to study the effect of chronic magnesium supplementation on anxiety-like behavior in rats by supplementing with magnesium their drinking water for 30 days. Anxiety-like behavior was induced by subcutaneous injection of veratrin 30 min before performing elevated plus maze and open field tests to measure anxiety levels and locomotion, respectively. We quantify the concentration of magnesium in plasma and cerebrospinal fluid. We used diazepam to compare the efficacy of magnesium supplementation as an anxiolytic agent. Our results show that rats supplemented with magnesium had a statistically significant decrease in anxiety levels with not effects on locomotion and a statistically significant increase in concentration of magnesium in plasma and cerebrospinal fluid. However, the anxiolytic effect of magnesium supplementation washes-out in 12 days. We discuss the advantages of using supplemental magnesium as anxiolytic.


Assuntos
Ansiolíticos/farmacologia , Ansiedade , Comportamento Animal/efeitos dos fármacos , Cloreto de Magnésio/farmacologia , Animais , Ansiolíticos/administração & dosagem , Ansiedade/sangue , Ansiedade/líquido cefalorraquidiano , Ansiedade/dietoterapia , Ansiedade/tratamento farmacológico , Diazepam/farmacologia , Modelos Animais de Doenças , Magnésio/sangue , Magnésio/líquido cefalorraquidiano , Cloreto de Magnésio/administração & dosagem , Ratos , Ratos Wistar
9.
Mar Biotechnol (NY) ; 23(4): 590-601, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34272626

RESUMO

Germ cell cryopreservation has been used to preserve many fish species. However, this method has not been established for crustaceans; thus, we attempted to do this herein. The efficiency of slow freezing was compared to vitrification methods for germ cell cryopreservation in two types of marine shrimp, Fenneropenaeus merguiensis and Penaeus monodon. In situ hybridization with a vasa probe was used to identify germ cells. The effects of three cryoprotectants, dimethyl sulfoxide (DMSO), glycerol (GLY), and magnesium chloride (MgCl2), on germ cell viability and recovery rate were compared at three concentrations (5%, 10%, and 15%). The effects of thawing temperature, including 10 and 27 °C, were also investigated. We discovered that 10% DMSO with the vitrification is suitable for preserving the germ cells of F. merguiensis for a long time, whereas 10% GLY with vitrification is suitable for P. monodon. Moreover, the most suitable thawing temperature was 10 °C for both species. This is the first report of germ cell cryopreservation in crustaceans. Thus, we provide evidence that crustacean germ cells can be preserved long-term in liquid nitrogen; this is the first step in the sustainable preservation of crustaceans, especially shrimp.


Assuntos
Criopreservação/métodos , Crioprotetores/farmacologia , Penaeidae , Testículo , Animais , Dimetil Sulfóxido/farmacologia , Congelamento , Glicerol/farmacologia , Cloreto de Magnésio/farmacologia , Masculino , Espermatogônias/citologia , Vitrificação
10.
Carbohydr Polym ; 265: 117918, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-33966818

RESUMO

In the present research, an optimized liquid medium which had no neutralizing effect to chitosan was developed. Moreover, magnesium chloride (MgCl2) was identified to be able to absolutely neutralize the antibacterial activity of chitosan and its derivatives. Took the two results together, the minimum bactericidal concentration (MBC) and minimum inhibitory concentration (MIC) of chitosan were precisely quantified through a further improved method based on the optimized medium and the relation curve between antibacterial rate and reaction time was obtained with the help of MgCl2 neutralizer. The MBC and MIC of chitosan were all 30 µg/mL against Staphylococcus aureus and Escherichia coli, and 100 µg/mL of chitosan acetate could reach 100 % of antibacterial rate within 3 min. Furthermore, coordination between magnesium ions and chitosan as well as reduced zeta potential of chitosan caused by coordination were inferred to be the neutralizing mechanism of MgCl2 neutralizer.


Assuntos
Antibacterianos/farmacologia , Quitosana/farmacologia , Escherichia coli/efeitos dos fármacos , Cloreto de Magnésio/farmacologia , Testes de Sensibilidade Microbiana , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Staphylococcus aureus/efeitos dos fármacos
11.
Int J Mol Sci ; 22(7)2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33804889

RESUMO

In chronic kidney disease, hyperphosphatemia upregulates the Ca2+ channel ORAI and its activating Ca2+ sensor STIM in megakaryocytes and platelets. ORAI1 and STIM1 accomplish store-operated Ca2+ entry (SOCE) and play a key role in platelet activation. Signaling linking phosphate to upregulation of ORAI1 and STIM1 includes transcription factor NFAT5 and serum and glucocorticoid-inducible kinase SGK1. In vascular smooth muscle cells, the effect of hyperphosphatemia on ORAI1/STIM1 expression and SOCE is suppressed by Mg2+ and the calcium-sensing receptor (CaSR) agonist Gd3+. The present study explored whether sustained exposure to Mg2+ or Gd3+ interferes with the phosphate-induced upregulation of NFAT5, SGK1, ORAI1,2,3, STIM1,2 and SOCE in megakaryocytes. To this end, human megakaryocytic Meg-01 cells were treated with 2 mM ß-glycerophosphate for 24 h in the absence and presence of either 1.5 mM MgCl2 or 50 µM GdCl3. Transcript levels were estimated utilizing q-RT-PCR, protein abundance by Western blotting, cytosolic Ca2+ concentration ([Ca2+]i) by Fura-2 fluorescence and SOCE from the increase in [Ca2+]i following re-addition of extracellular Ca2+ after store depletion with thapsigargin (1 µM). As a result, Mg2+ and Gd3+ upregulated CaSR and blunted or virtually abolished the phosphate-induced upregulation of NFAT5, SGK1, ORAI1,2,3, STIM1,2 and SOCE in megakaryocytes. In conclusion, Mg2+ and the CaSR agonist Gd3+ interfere with phosphate-induced dysregulation of [Ca2+]i in megakaryocytes.


Assuntos
Sinalização do Cálcio , Gadolínio/farmacologia , Cloreto de Magnésio/farmacologia , Megacariócitos/efeitos dos fármacos , Proteína ORAI1/metabolismo , Células Cultivadas , Humanos , Proteínas Imediatamente Precoces/genética , Proteínas Imediatamente Precoces/metabolismo , Megacariócitos/metabolismo , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Proteína ORAI1/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Molécula 1 de Interação Estromal/genética , Molécula 1 de Interação Estromal/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
12.
Int J Mol Sci ; 21(24)2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33334011

RESUMO

HU is a nucleoid-associated protein expressed in most eubacteria at a high amount of copies (tens of thousands). The protein is believed to bind across the genome to organize and compact the DNA. Most of the studies on HU have been carried out in a simple in vitro system, and to what extent these observations can be extrapolated to a living cell is unclear. In this study, we investigate the DNA binding properties of HU under conditions approximating physiological ones. We report that these properties are influenced by both macromolecular crowding and salt conditions. We use three different crowding agents (blotting grade blocker (BGB), bovine serum albumin (BSA), and polyethylene glycol 8000 (PEG8000)) as well as two different MgCl2 conditions to mimic the intracellular environment. Using tethered particle motion (TPM), we show that the transition between two binding regimes, compaction and extension of the HU protein, is strongly affected by crowding agents. Our observations suggest that magnesium ions enhance the compaction of HU-DNA and suppress filamentation, while BGB and BSA increase the local concentration of the HU protein by more than 4-fold. Moreover, BGB and BSA seem to suppress filament formation. On the other hand, PEG8000 is not a good crowding agent for concentrations above 9% (w/v), because it might interact with DNA, the protein, and/or surfaces. Together, these results reveal a complex interplay between the HU protein and the various crowding agents that should be taken into consideration when using crowding agents to mimic an in vivo system.


Assuntos
Proteínas de Bactérias/química , Proteínas de Ligação a DNA/química , Modelos Moleculares , Conformação Proteica , Algoritmos , DNA/química , DNA Bacteriano/química , DNA Bacteriano/metabolismo , Cloreto de Magnésio/química , Cloreto de Magnésio/farmacologia , Modelos Teóricos , Polietilenoglicóis/química , Ligação Proteica
13.
J Dairy Sci ; 103(12): 11762-11768, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33041044

RESUMO

Although incidence of clinical hypocalcemia in postpartum dairy cows is low in US dairies, subclinical hypocalcemia after calving is common and has been associated with metabolic and infectious disease. It is widespread farm practice to feed a diet rich in anions to prepartum dairy cattle to support calcium homeostasis. However, this diet is typically discontinued at parturition, when calcium needs are still high. The objective of this trial was to determine the effects of extending metabolic acidification into the first 3 d of lactation in multiparous Holstein cows with the use of magnesium chloride (MgCl2) hexahydrate drenches on blood ionized calcium concentrations. Adult Holstein cows at a commercial dairy in their second or higher lactation, with a urine pH of 6.8 or less on the day of calving, were randomly assigned to either treatment or control groups, resulting in 13 cows in the treatment group and 14 cows in the control group. Treatment cows received 480 g of oral MgCl2 hexahydrate once daily for 3 d for continued acidification starting on the day of calving, whereas cows in the control group received no treatment. Urine pH was measured daily for 5 d, starting on the day of calving (0 DIM), to assess acidification status; blood was collected on day of calving (0 DIM), 2 DIM, and 4 DIM and analyzed for ionized calcium concentrations. Differences in blood ionized calcium and urine pH over time were compared using longitudinal data analysis. Urine pH was lower in treatment cows compared with control cows at 1, 2, and 3 DIM. Blood ionized calcium concentrations were different from baseline, taken at enrollment (0 DIM) and at 2 and 4 DIM in both treatment and control cows. However, no difference was detectable between treatment and control cows at 2 or 4 DIM with respect to blood ionized calcium concentrations. Oral supplementation with MgCl2 hexahydrate resulted in the desired acidification of urine pH in the treatment group, similar to feeding of an anionic close-up diet. Continued acidification of dairy cows until 2 DIM did not result in clinically meaningful higher blood calcium concentrations compared with controls, and further research is needed, to identify physiological reasons for this finding.


Assuntos
Ração Animal , Cálcio/sangue , Bovinos/sangue , Lactação , Cloreto de Magnésio/farmacologia , Animais , Ânions/administração & dosagem , Dieta/veterinária , Feminino , Homeostase/fisiologia , Concentração de Íons de Hidrogênio , Lactação/fisiologia , Leite/química , Período Pós-Parto/metabolismo , Urina
14.
J Immunol Methods ; 487: 112875, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33031794

RESUMO

The expression of Kv1.3 and KCa channels in human T cells is essential for maintaining cell activation, proliferation and migration during an inflammatory response. Recently, an additional residual current, sensitive to anandamide and A293, compounds specifically inhibiting currents mediated by TASK channels, was observed after complete pharmacological blockade of Kv1.3 and KCa channels. This finding was not consistently observed throughout different studies and, an in-depth review of the different recording conditions used for the electrophysiological analysis of K+ currents in T cells revealed fluoride as major anionic component of the pipette intracellular solutions in the initial studies. While fluoride is frequently used to stabilize electrophysiological recordings, it is known as G-protein activator and to influence the intracellular Ca2+ concentration, which are mechanisms known to modulate TASK channel functioning. Therefore, we systemically addressed different fluoride- and chloride-based pipette solutions in whole-cell patch-clamp experiments in human T cells and used specific blockers to identify membrane currents carried by TASK and Kv1.3 channels. We found that fluoride increased the decay time constant of K+ outward currents, reduced the degree of the sustained current component and diminished the effect of the specific TASK channels blocker A293. These findings indicate that the use of fluoride-based pipette solutions may hinder the identification of a functional TASK channel component in electrophysiological experiments.


Assuntos
Fluoretos/farmacologia , Potenciais da Membrana/efeitos dos fármacos , Canais de Potássio de Domínios Poros em Tandem/metabolismo , Compostos de Potássio/farmacologia , Linfócitos T/efeitos dos fármacos , Células Cultivadas , Fluoretos/metabolismo , Humanos , Canal de Potássio Kv1.3/efeitos dos fármacos , Canal de Potássio Kv1.3/metabolismo , Cloreto de Magnésio/metabolismo , Cloreto de Magnésio/farmacologia , Técnicas de Patch-Clamp , Bloqueadores dos Canais de Potássio/farmacologia , Canais de Potássio de Domínios Poros em Tandem/efeitos dos fármacos , Compostos de Potássio/metabolismo , Linfócitos T/metabolismo , Fatores de Tempo
15.
Mol Med Rep ; 22(5): 3904-3910, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32901870

RESUMO

Magnesium, an important inorganic mineral component in bones, enhances osteoblast adhesion and osteogenic gene expression. Mg2+­containing hydroxyapatite promotes mouse mesenchymal stem cell (MMSC) osteogenic differentiation. In the present study, MMSCs were cultured in media containing different concentrations of MgCl2 (0 and 20 mM) for different time periods. Western blotting and reverse transcription­quantitative PCR were performed to determine the expression levels of phosphorylated (p)­p38 mitogen­activated protein kinase (MAPK), the osteoblast­specific transcription factor Osterix (Osx), runt­related transcription factor 2 (Runx2), and p38 downstream genes, such as 27 kDa heat shock protein (hsp27), activating transcription factor 4 (Atf4), myocyte enhancer factor 2C (Mef2c) and CCAAT/enhancer­binding protein homologous protein (Ddit3). The facilitatory effect of MgCl2 on MMSC osteogenic differentiation was assessed via Alizarin Red staining. The results suggested that MgCl2 increased p38 phosphorylation compared with the control group. Downstream genes of the p38 signaling pathway, including Osx and Runx2, as well as several osteogenesis­associated downstream target genes, including Hsp27, Atf4, Ddit3 and Mef2c, were significantly upregulated in the Mg2+­treated group compared with the control group. The increased osteogenic differentiation in the Mg2+­treated group was significantly attenuated in MMSCs treated with SB203580, a specific inhibitor of the p38 signaling pathway. The results suggested that appropriate concentrations of MgCl2 promoted MMSC osteogenic differentiation via regulation of the p38/Osx/Runx2 signaling pathway.


Assuntos
Cloreto de Magnésio/farmacologia , Células-Tronco Mesenquimais/citologia , Osteogênese , Transdução de Sinais/efeitos dos fármacos , Animais , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Camundongos , Fosforilação/efeitos dos fármacos , Fator de Transcrição Sp7/genética , Fator de Transcrição Sp7/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
16.
Biochem Biophys Res Commun ; 531(4): 588-594, 2020 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-32814632

RESUMO

Magnesium is well known as a biodegradable biomaterial that has been reported to promote bone remodeling in several studies; however, the underlying biological mechanism remains unclear. In the present study, the role of magnesium ions in the migration of U-2 OS cells, which are osteoblast-like cell lines, was investigated. Magnesium treatment did not significantly alter the global transcriptome of U-2 OS cells, but increased the protein expression level of SNAI2, an epithelial-mesenchymal transition (EMT) marker. In addition, it was confirmed that the junctional site localization of Zona-occludens 1 (ZO-1), a representative tight junction protein, was destroyed by magnesium treatment; furthermore, it was determined that cytoplasmic localization increased, and alkaline phosphatase (ALP) activity increased. The obtained results on the mechanism by which magnesium is involved in osteoblast migration, which is important for fracture healing, will contribute to the understanding of the bone-formation process in patients with osteoporosis and musculoskeletal injury.


Assuntos
Cloreto de Magnésio/farmacologia , Osteoblastos/efeitos dos fármacos , Fosfatase Alcalina/metabolismo , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Transição Epitelial-Mesenquimal/fisiologia , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Microscopia de Fluorescência , Osteoblastos/citologia , Osteoblastos/metabolismo , Análise de Sequência de RNA , Fatores de Transcrição da Família Snail/metabolismo , Proteína da Zônula de Oclusão-1/metabolismo
17.
Trials ; 21(1): 428, 2020 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-32450917

RESUMO

BACKGROUND: Delayed graft function, the requirement for dialysis due to poor kidney function post-transplant, is a frequent complication of deceased donor kidney transplantation and is associated with inferior outcomes and higher costs. Intravenous fluids given during and after transplantation may affect the risk of poor kidney function after transplant. The most commonly used fluid, isotonic sodium chloride (0.9% saline), contains a high chloride concentration, which may be associated with acute kidney injury, and could increase the risk of delayed graft function. Whether using a balanced, low-chloride fluid instead of 0.9% saline is safe and improves kidney function after deceased donor kidney transplantation is unknown. METHODS: BEST-Fluids is an investigator-initiated, pragmatic, registry-based, multi-center, double-blind, randomized controlled trial. The primary objective is to compare the effect of intravenous Plasma-Lyte 148 (Plasmalyte), a balanced, low-chloride solution, with the effect of 0.9% saline on the incidence of delayed graft function in deceased donor kidney transplant recipients. From January 2018 onwards, 800 participants admitted for deceased donor kidney transplantation will be recruited over 3 years in Australia and New Zealand. Participants are randomized 1:1 to either intravenous Plasmalyte or 0.9% saline peri-operatively and until 48 h post-transplant, or until fluid is no longer required; whichever comes first. Follow up is for 1 year. The primary outcome is the incidence of delayed graft function, defined as dialysis in the first 7 days post-transplant. Secondary outcomes include early kidney transplant function (composite of dialysis duration and rate of improvement in graft function when dialysis is not required), hyperkalemia, mortality, graft survival, graft function, quality of life, healthcare resource use, and cost-effectiveness. Participants are enrolled, randomized, and followed up using the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry. DISCUSSION: If using Plasmalyte instead of 0.9% saline is effective at reducing delayed graft function and improves other clinical outcomes in deceased donor kidney transplantation, this simple, inexpensive change to using a balanced low-chloride intravenous fluid at the time of transplantation could be easily implemented in the vast majority of transplant settings worldwide. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry: ACTRN12617000358347. Registered on 8 March 2017. ClinicalTrials.gov: NCT03829488. Registered on 4 February 2019.


Assuntos
Função Retardada do Enxerto/epidemiologia , Transplante de Rim/efeitos adversos , Assistência Perioperatória/métodos , Administração Intravenosa , Austrália , Ensaios Clínicos Fase III como Assunto , Função Retardada do Enxerto/etiologia , Método Duplo-Cego , Hidratação/métodos , Gluconatos/farmacologia , Sobrevivência de Enxerto , Humanos , Cloreto de Magnésio/farmacologia , Estudos Multicêntricos como Assunto , Complicações Pós-Operatórias/epidemiologia , Cloreto de Potássio/farmacologia , Ensaios Clínicos Pragmáticos como Assunto , Qualidade de Vida , Sistema de Registros , Solução Salina/farmacologia , Acetato de Sódio/farmacologia , Cloreto de Sódio/farmacologia , Doadores de Tecidos , Resultado do Tratamento
18.
Curr Microbiol ; 77(6): 959-966, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31989213

RESUMO

The study of effects of Ca2+ and Mg2+ on antifungal activity of lactic acid bacteria (LAB) isolates and their associations revealed inducing and inhibiting effects on antifungal activity. The addition of Ca2+ essentially inhibited the antifungal effect of L. rhamnosus MDC9661 but stimulated the activity of RIN-2003-Ls, MDC9632 and MDC9633 strains, as well as their associations. Mg2+ partly increased the inhibitory activity of LAB isolates, while the addition of ions combination did not cause changes of their antifungal activity. The supplementation of Ca2+ stimulated the antifungal effect of most associations against Penicillium sp., Trichoderma viride, Geotrichum candidum, and Aspergillus flavus compared with the native conditions. The addition of Mg2+ induced the antifungal activity of RIN-2003-Ls, MDC9632, MDC9633, and INR-2010-Tsov-G-St combinations. The antifungal effects of most associations were increased in the presence of ions mixture. The natural LAB associations including VKPM B-3386, MDC9632, and MDC9633 could not suppress the growth of any tested mold; however, the supplementation of ions combination revealed their antifungal effect against all kinds of molds. The finding of substantial stimulation of the most LAB associations antifungal effect by metal ions can be basis for creation of new effective antifungal preparations by the supplementation of ions combined mixture.


Assuntos
Antifúngicos/farmacologia , Cátions Bivalentes/farmacologia , Lactobacillales/fisiologia , Antibiose , Cloreto de Cálcio/farmacologia , Fungos/efeitos dos fármacos , Cloreto de Magnésio/farmacologia , Testes de Sensibilidade Microbiana
19.
Mol Divers ; 24(2): 463-476, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-30980342

RESUMO

MgCl2 has been reported to be a versatile reagent especially as a Lewis acid catalyst in a variety of organic transformations including the preparation of heterocyclic compounds, the protection of functional groups and condensation reaction. Also the use of MgCl2 in the preparation of metallic magnesium and the application of magnesium chloride in biochemistry such as anesthetic for cephalopods, the separation of serum high-density lipoprotein, effect of MgCl2 on rabbit bronchial smooth muscle, antimicrobial properties of magnesium chloride and effect of MgCl2 on the quality of life for patients with fibromyalgia have been reported. Therefore, in this article the use of MgCl2 in organic chemistry and biochemistry is reviewed. MgCl2 has been reported to be a versatile reagent especially as a Lewis acid catalyst in a variety of organic transformations including the preparation of heterocyclic compounds, the protection of functional groups and condensation reaction. Also the use of MgCl2 in the preparation of metallic magnesium and the application of magnesium chloride in biochemistry such as anesthetic for cephalopods, the separation of serum high-density lipoprotein, effect of MgCl2 on rabbit bronchial smooth muscle, antimicrobial properties of magnesium chloride and effect of MgCl2 on the quality of life for patients with fibromyalgia have been reported. Therefore, in this article the use of MgCl2 in organic chemistry and biochemistry is reviewed.


Assuntos
Cloreto de Magnésio/química , Cloreto de Magnésio/farmacologia , Animais , Bioquímica , Química Orgânica , Corantes/química , Humanos , Poluentes Químicos da Água/química , Purificação da Água
20.
Biochem Biophys Res Commun ; 523(1): 18-24, 2020 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-31831178

RESUMO

In chronic kidney disease, renal phosphate retention leads to hyperphosphatemia with subsequent vascular osteogenic signaling and calcification. Osteogenic signaling involves up-regulation of the transcription factors CBFA1, MSX2, and SOX9, as well as alkaline phosphatase (ALP), an enzyme stimulating calcification by degrading the calcification inhibitor pyrophosphate. Stimulation of osteogenic signaling and calcification by phosphate donor ß-glycerophosphate in human aortic smooth muscle cells (HAoSMCs) is attenuated by MgCl2, an effect mimicked by Ca2+-sensing receptor agonist GdCl3. Most recent observations revealed that the effect of ß-glycerophosphate on osteogenic signaling requires ORAI1, a Ca2+-channel accomplishing store-operated Ca2+-entry (SOCE), which is stimulated by Ca2+-sensor STIM1. The present study explored whether ORAI1 and/or STIM1 expression and, thus, SOCE and osteogenic signaling in HAoSMCs are sensitive to MgCl2 and/or GdCl3. To this end, transcript levels were estimated using q-RT-PCR, protein abundance with western blotting, cytosolic Ca2+-concentration ([Ca2+]i) by Fura-2-fluorescence, and SOCE from increase of [Ca2+]i following re-addition of extracellular Ca2+ after store depletion with thapsigargin (1  µM). As a result, 24 h exposure to ß-glycerophosphate (2 mM) significantly enhanced transcript levels of ORAI1 and STIM1 as well as SOCE, effects significantly blunted or virtually abrogated by 1.5 mM MgCl2 and by 50  µM GdCl3. In conclusion, MgCl2 and GdCl3 are powerful inhibitors of ORAI1 and STIM1 expression and store-operated Ca2+-entry, effects affecting osteogenic signalling in vascular smooth muscle cells.


Assuntos
Cálcio/metabolismo , Cloreto de Magnésio/farmacologia , Miócitos de Músculo Liso/efeitos dos fármacos , Proteína ORAI1/biossíntese , Osteogênese/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Células Cultivadas , Gadolínio/farmacologia , Humanos , Miócitos de Músculo Liso/metabolismo , Proteína ORAI1/genética , Proteína ORAI1/metabolismo
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