Increase In Calcium Concentration Research Articles

Ghrelin Action in the PVH of Male Mice: Accessibility, Neuronal Targets, and CRH Neurons Activation.

The hormone ghrelin displays several well-characterized functions, including some with pharmaceutical interest. The receptor for ghrelin, the growth hormone secretagogue receptor (GHSR), is expressed in the hypothalamic paraventricular nucleus (PVH), a critical hub for the integration of metabolic, neuroendocrine, autonomic, and behavioral functions. Here, we performed a neuroanatomical and functional characterization of the neuronal types mediating ghrelin actions in the PVH of male mice. We found that fluorescent ghrelin mainly labels PVH neurons immunoreactive for nitric oxide synthase 1 (NOS1), which catalyze the production of nitric oxide [NO]). Centrally injected ghrelin increases c-Fos in NOS1 PVH neurons and NOS1 phosphorylation in the PVH. We also found that a high dose of systemically injected ghrelin increases the ghrelin level in the cerebrospinal fluid and in the periventricular PVH, and induces c-Fos in NOS1 PVH neurons. Such a high dose of systemically injected ghrelin activates a subset of NOS1 PVH neurons, which do not express oxytocin, via an arcuate nucleus-independent mechanism. Finally, we found that pharmacological inhibition of NO production fully abrogates ghrelin-induced increase of calcium concentration in corticotropin-releasing hormone neurons of the PVH whereas it partially impairs ghrelin-induced increase of plasma glucocorticoid levels. Thus, plasma ghrelin can directly target a subset of NO-producing neurons of the PVH that is involved in ghrelin-induced activation of the hypothalamic-pituitary-adrenal neuroendocrine axis.

Mitochondrial Oxidative Stress Is the General Reason for Apoptosis Induced by Different-Valence Heavy Metals in Cells and Mitochondria.

This review analyzes the causes and consequences of apoptosis resulting from oxidative stress that occurs in mitochondria and cells exposed to the toxic effects of different-valence heavy metals (Ag+, Tl+, Hg2+, Cd2+, Pb2+, Al3+, Ga3+, In3+, As3+, Sb3+, Cr6+, and U6+). The problems of the relationship between the integration of these toxic metals into molecular mechanisms with the subsequent development of pathophysiological processes and the appearance of diseases caused by the accumulation of these metals in the body are also addressed in this review. Such apoptosis is characterized by a reduction in cell viability, the activation of caspase-3 and caspase-9, the expression of pro-apoptotic genes (Bax and Bcl-2), and the activation of protein kinases (ERK, JNK, p53, and p38) by mitogens. Moreover, the oxidative stress manifests as the mitochondrial permeability transition pore (MPTP) opening, mitochondrial swelling, an increase in the production of reactive oxygen species (ROS) and H2O2, lipid peroxidation, cytochrome c release, a decline in the inner mitochondrial membrane potential (ΔΨmito), a decrease in ATP synthesis, and reduced glutathione and oxygen consumption as well as cytoplasm and matrix calcium overload due to Ca2+ release from the endoplasmic reticulum (ER). The apoptosis and respiratory dysfunction induced by these metals are discussed regarding their interaction with cellular and mitochondrial thiol groups and Fe2+ metabolism disturbance. Similarities and differences in the toxic effects of Tl+ from those of other heavy metals under review are discussed. Similarities may be due to the increase in the cytoplasmic calcium concentration induced by Tl+ and these metals. One difference discussed is the failure to decrease Tl+ toxicity through metallothionein-dependent mechanisms. Another difference could be the decrease in reduced glutathione in the matrix due to the reversible oxidation of Tl+ to Tl3+ near the centers of ROS generation in the respiratory chain. The latter may explain why thallium toxicity to humans turned out to be higher than the toxicity of mercury, lead, cadmium, copper, and zinc.

Ezetimibe Induces Vasodilation in Rat Mesenteric Resistance Arteries through Inhibition of Extracellular Ca2+ Influx.

Ezetimibe is a lipid-lowering agent that selectively inhibits cholesterol absorption by binding to the Niemann-Pick C1-like 1 (NPC1L1) protein. Although it is well known that administration of ezetimibe in hypercholesterolemia patients reduces the risk of cardiovascular events through attenuation of atherosclerosis, studies on the direct effect of ezetimibe on vascular function are not sufficient. The aim of the present study was to investigate the vascular effects of ezetimibe in rat mesenteric arteries. In the present study, 12-week-old male Sprague Dawley rats were used. After the rats were sacrificed, the second branches of the mesenteric arteries were isolated and cut into 2-3 mm segments and mounted in a multi-wire myography system to measure isometric tension. Ezetimibe reduced vasoconstriction induced by U46619 (500 nM) in endothelium-intact and endothelium-denuded arteries. Ezetimibe-induced vasodilation was not affected by the endothelial nitric oxide synthase (eNOS) inhibitor Nω-Nitro-L-arginine (L-NNA, 300 μM) or the non-selective potassium channel blocker, tetraethylammonium (TEA, 10 mM). Moreover, ezetimibe also completely blocked the contraction induced by an increase in external calcium concentration. Ezetimibe significantly reduced vascular contraction induced by L-type Ca2+ channel activator (Bay K 8644, 30 nM). Treatment with ezetimibe decreased the phosphorylation level of 20 kDa myosin light chain (MLC20) in vascular smooth muscle cells. In the present study, we found that ezetimibe has a significant vasodilatory effect in rat mesenteric resistance arteries. These results suggest that ezetimibe may have beneficial cardiovascular effects beyond its cholesterol-lowering properties.

Removal of copper contamination from simulated wastewater using chitosan and shrimp waste: Equilibrium analysis

This study addressed copper removal from aqueous solution using unprocessed shrimp tail shell waste (STW) with comparison to removal by chitosan derived from shrimp shell. The use of a copper ion selective electrode enabled continuous copper concentration measurement and determination of the STW mass-time relationship needed to achieve the USEPA Maximum Contaminant Level for copper as a function of adsorbent dose. Copper removal using chitosan produced a blue solid without surface morphology changes, consistent with an adsorption or ion exchange mechanism. Calcium carbonate in the STW was essential for copper removal by the formation of a green copper-containing deposit primarily on the exposed edges of the ground shrimp solids and an increase in calcium concentration and pH in the treated solution. The systems reached equilibrium over several days. Equilibrium data were fitted to the Freundlich, Langmuir, Temkin, Sips, and B-E-T isotherms and the Freundlich model fit the data well. Raw STW, cooked STW, and chitosan with particle sizes ranging from 425 to 850 µm gave a maximum copper loading of 184 mg/g, 170 mg/g, and 129 mg/g, respectively. Both raw and cooked STW had higher copper capacities than commercial chitosan and provide a low cost and environmentally friendly adsorbent. Comparison of small particle size (< 425 µm) adsorbents after six hours showed that raw STW had double the copper loading of chitosan. Small STW achieved greater than 97.4% copper removal from a 50 mg/L copper solution and reached the MCL in less than one hour for 1.5 g/L loadings.

Alginate Conjugation Increases Toughness in Auricular Chondrocyte Seeded Collagen Hydrogels.

Current auricular cartilage replacements for pediatric microtia fail to address the need for long-term integration and neocartilage formation. While collagen hydrogels have been successful in fostering neocartilage formation, the toughness and extensibility of these materials do not match that of native tissue. This study used the N-terminal functionalization of collagen with alginate oligomers to improve toughness and extensibility through metal-ion complexation. Alginate conjugation was confirmed via FTIR spectroscopy. The retention of native collagen fibrillar structure, thermal gelation, and helical conformation in functionalized gels was confirmed via scanning electron microscopy, oscillatory shear rheology, and circular dichroism spectroscopy, respectively. Alginate-calcium complexation enabled a more than two-fold increase in modulus and work density in functionalized collagen with the addition of 50 mM CaCl2, whereas unmodified collagen decreased in both modulus and work density with increasing calcium concentration. Additionally, the extensibility of alginate-functionalized collagen was increased at 25 and 50 mM CaCl2. Following 2-week culture with auricular chondrocytes, alginate-functionalization had no effect on the cytocompatibility of collagen gels, with no effects on cell density, and increased glycosaminoglycan deposition. Custom MATLAB video analysis was then used to quantify fracture toughness, which was more than 5-fold higher following culture in functionalized collagen and almost three-fold higher in unmodified collagen.

Calcineurin-Dependent Homeostatic Response of C. elegans Muscle Cells upon Prolonged Activation of Acetylcholine Receptors.

Pharmacological adaptation is a common phenomenon observed during prolonged drug exposure and often leads to drug resistance. Understanding the cellular events involved in adaptation could provide new strategies to circumvent this resistance issue. We used the nematode Caenorhabditis elegans to analyze the adaptation to levamisole, an ionotropic acetylcholine receptor agonist, used for decades to treat nematode parasitic infections. Genetic screens in C. elegans identified "adapting mutants" that initially paralyze upon exposure to levamisole as the wild type (WT), but recover locomotion after a few hours whereas WT remain paralyzed. Here, we show that levamisole induces a sustained increase in cytosolic calcium concentration in the muscle cells of adapting mutants, lasting several hours and preceding a decrease in levamisole-sensitive acetylcholine receptors (L-AChR) at the muscle plasma membrane. This decrease correlated with a drop in calcium concentration, a relaxation of the animal's body and a resumption of locomotion. The decrease in calcium and L-AChR content depends on calcineurin activation in muscle cells. We also showed that levamisole adaptation triggers homeostatic mechanisms in muscle cells including mitochondria remodeling, lysosomal tubulation and an increase in autophagic activity. Levamisole adaptation thus provides a new experimental paradigm for studying how cells cope with calcium stress.

Exploring the structural and magnetic characteristics of ferrous ferric oxide nanoparticles doped with Ca2+ ions for nanoscale devices

In this study, we investigate the effect of Ca2+ substitution on the structural and magnetic characteristics of ferrous ferric oxide CaxFe3-xO4 (x = 0.2 and 0.4) nanoparticles produced by the sol–gel auto combustion method with citric acid as a fuel agent. X-Ray Diffraction (XRD) results show that the average crystallite size is in the range of 20–22 nm and lattice parameter decreases with increasing calcium concentration. Field Emission Scanning Electron Microscope (FESEM) image shows the crystalline nature of calcium-substituted ferrous ferric oxide nanoparticles. Electron Diffraction Spectra (EDS) confirms the presence of Fe, Ca, and O atoms in prepared sample. Vibrating Sample Magnetometer (VSM) measures the magnetic field at room temperature which confirm the existence of a superparamagnetic behavior of Ca2+ substituted ferrous ferric oxide nanoparticles which plays an essential role in nanoscale devices such as MRI, MRAM, spin valve, MTJ, and bio-sensing devices applications.

Control of the Ionic Composition of Nanofiltration Membrane Permeate to Improve Product Water Quality in Drinking Water Supply Applications

Reverse osmosis is efficiently used for producing drinking water from groundwater sources containing dissolved impurities, including fluoride, ammonia, lithium, strontium, boron, arsenic, etc. The principal problems of utilizing reverse osmosis include scaling on membrane surfaces, concentrate discharges, and low permeate TDS that often require conditioning. The main goal of this work was to demonstrate the viability of a newly developed methodology that relies on low-rejection nanofiltration membranes to improve product water quality by increasing its TDS and calcium content, and its economic efficiency compared to conventionally used reverse osmosis. Disadvantages of employing reverse osmosis for the production of drinking water are attributed to the fact that several pollutants (including lithium, ammonia, and boron) are monovalent ions and, as such, are poorly rejected by membranes as compared to calcium, sodium, sulfate, and chloride ions. Thus, in cases in which lithium or ammonia are present in high concentrations, high rejection membranes are usually used that result in low TDS of the product water. This article presents the results of research aimed at developing a new approach to changing the ratio of monovalent and divalent ions in product water. The new method described in this paper relies on low rejection membranes in a two-stage application that enables us to reduce monovalent impurities and increase the concentration of calcium and TDS values in product water while leaving lithium concentration unchanged. This is achieved by applying a two-stage scheme with low-rejection membranes instead of the reverse osmosis stage. The two-stage treatment using nanofiltration membranes results in the same rejection of lithium and product water quality as reverse osmosis. However, the ratio value of calcium and lithium concentrations in the concentrate of nanofiltration membranes appears to be significantly higher compared with the ratio measured in the feed groundwater. This can be attributed to different rejections of these ions by membranes. Therefore, concentration (reduction of volume) of the feed water with nanofiltration membranes and further dilution of the concentrate with deionized water produce the same concentration of lithium and are associated with an increase of 2–4 times the concentration of calcium. Treatment of this water in the second nanofiltration membrane stage produces drinking-quality water with the required lithium content and increased calcium concentration. We focus on the real-world example of groundwater treatment in Yakutia, Russia, an area where lithium concentration exceeds drinking standards by 24 times. The paper presents a technique of ion separation and demonstrates experimental results that provide lithium removal while increasing the calcium concentration and TDS value. The resulting concentrations are 2–5 times lower than those obtained via conventional use of reverse osmosis membranes. A series of experiments were conducted to remove lithium from groundwater and demonstrate the efficiency of the newly developed method of ion separation. Experimental results of the concentration of obtained values of lithium, calcium, and TDS in permeate and concentrate flows at each membrane stage demonstrate that they provide separation of monovalent and divalent ions and increase product water TDS without increasing lithium. This experimental approach increases calcium and TDS values in product water by 2–4 times compared with the use of reverse osmosis membranes. Calculations of operational costs for different options (the use of reverse osmosis, two-stage nanofiltration, and ion separation in a two-stage approach) are presented. These results confirm the economic advantage of nanofiltration membrane applications to remove lithium as compared to the use of high-rejection reverse osmosis membranes. The increase in product water TDS facilitates the further reduction of concentrate flow rate and operational costs. The economic comparison involved the calculation of the required membrane area and number of membrane elements at each stage, calcium carbonate scaling rates, reagent consumption to prevent scaling, and amounts of concentrate discharged into the sewer. Experimentally obtained results confirmed the feasibility of increasing the calcium concentration and TDS values in product water by 2–5 times while leaving the lithium concentration at the same level. Design characteristics to calculate operational costs for conventional and new options are calculated and demonstrate a sufficient (30–40%) reduction of operational costs compared to conventional use of reverse osmosis. The reduction in reagent consumption is attributed to the utilization of low-rejection nanofiltration membranes that have lower scaling propensities compared with reverse osmosis membranes and a smaller payment for concentrate discharge. The developed approach to using two-stage nanofiltration instead of single-stage reverse osmosis provides multiple advantages that include improved product water quality, lower concentrate consumption, and lower reagent consumption that are attributable to the use of low-rejection membranes. Different case studies are planned to demonstrate the efficiency of the proposed techniques to reduce ammonia, fluoride, and boron in drinking water.

Importance of Silicon in the Growth of Jatropha curcas L. Plants Irrigated With Salina Water

The use of silicon in plant cultivation is one of the strategies to mitigate the negative effects of salinity. This study aimed to evaluate the effect of silicate fertilization on the morphophysiological, biochemical and nutritional characteristics of Jatropha curcas L. plants under saline stress. The work was carried out in a greenhouse at the State University of Goi&amp;aacute;s. The experiment was set up in a completely randomized design in a 5 &amp;times; 2 factorial arrangement (plants irrigated with salt water with sodium chloride (NaCl) and electrical conductivities equal to 0 dS m-1; 2 dS m-1; 4 dS m-1; 6 dS m-1 and 8 dS m-1 applied at 80 days after emergence (DAE) and absence or presence of silica fertilization of 1 g L-1 with Si applied at 80 and 95 DAE by volume of 30 mL of the solution with the aid of a spray manual), five replicates and experimental plot of one plant per pot. The evaluations were carried out at 130 DAEs. The absence of differences in the concentrations of photosynthetic pigments and visible damages is indicative of the absence of severe toxic effects caused by salinity. The tolerance of Jatropha curcas L. plants to salinity is independent of silicon. The Jatropha curcas L. plant tolerates salinity by minimizing transpiration and remaining hydrated through the water stored in the succulent stem. In addition, the plants control sodium uptake and eliminate toxic compounds through increases in Calcium concentration and antioxidative metabolism respectively.

25(OH)D Concentration in Neonates, Infants, Toddlers, Older Children and Teenagers from Poland-Evaluation of Trends during Years 2014-2019.

Local and international guidelines have provided schedules for the vitamin D supplementation of general populations of different ages, including children. Our study aimed to assess 25(OH)D concentration and its potential change during a growth and maturation period, adding parameters that reflect the risk of hypercalcemia. The available 25(OH)D concentration values (n = 17,636; 7.8 ± 6.0 years), calcium (n = 2673; 16.3 ± 6.1 years) and phosphate (n = 2830; 3.8 ± 5.2 years) metabolism markers were analyzed in a studied group of patients (0-18 years). In the studied group the mean 25(OH)D concentration was 29.4 ± 11.7 ng/mL. Concentrations of 25(OH)D < 10 ng/mL were observed in 1.7% of patients (n = 292), 10-20 ng/mL in 17.2% (n = 3039), 20-30 ng/mL in 39.5% (n = 6960) and 30-50 ng/mL in 37.2% (n = 6567). In patients with a 25(OH)D concentration <10 ng/mL, normal calcemia (2.25-2.65 mmol/L) was observed in 29.5% of cases (n = 86). Three patients had 25(OH)D concentrations above 100 ng/mL with co-existing hypercalcemia; the mean was Ca = 3.40 mmol/L. Hypocalcemia (Ca < 2.25 mmol/L) was observed in 10,4% of patients (n = 2797). Furthermore, 5.0% of patients showed an increased calcium concentration >2.65 mmol/L (n = 1327). The highest mean 25(OH)D concentration of 32.1 ng/mL ± 12.9 was noted in the years 2018-2019 (n = 3931) and the lowest in the year 2015 (27.2 ng/mL ± 11.0; n = 2822). Vitamin D deficiency (<20 ng/mL) was noted in 18,9% of subjects in the years 2014-2019. An effective prevention of vitamin D deficiency was observed in children aged 3 years and younger. A relationship between the concentrations of calcium and 25(OH)D was not observed.

A nano-conductive osteogenic hydrogel to locally promote calcium influx for electro-inspired bone defect regeneration

Conductive nano-materials and electrical stimulation (ES) have been recognized as a synergetic therapy for ordinary excitable tissue repair. It is worth noting that hard tissues, such as bone tissue, possess bioelectrical properties as well. However, insufficient attention is paid to the synergetic therapy for bone defect regeneration via conductive biomaterials with ES. Here, a novel nano-conductive hydrogel comprising calcium phosphate-PEDOT:PSS-magnesium titanate-methacrylated alginate (CPM@MA) was synthesized for electro-inspired bone tissue regeneration. The nano-conductive CPM@MA hydrogel has demonstrated excellent electroactivity, biocompatibility, and osteoinductivity. Additionally, it has the potential to enhance cellular functionality by increasing endogenous transforming growth factor-beta1 (TGF-β1) and activating TGF-β/Smad2 signaling pathway. The synergetic therapy could facilitate intracellular calcium enrichment, resulting in a 5.8-fold increase in calcium concentration compared to the control group in the CPM@MA ES + group. The nano-conductive CPM@MA hydrogel with ES could significantly promote electro-inspired bone defect regeneration in vivo, uniquely allowing a full repair of rat femoral defect within 4 weeks histologically and mechanically. These results demonstrate that our synergistic strategy effectively promotes bone restoration, thereby offering potential advancements in the field of electro-inspired hard tissue regeneration using novel nano-materials with ES.

Development and characterization of an optimized novel drink from three varieties of sprouted quinoa

Sprouted products are a food alternative that contribute to improving human nutrition. Quinoa has a large amount of natural antioxidants. The dry and hard grains when they undergo a germination process change to tender and slightly acidic sprouts that contain amino acids, minerals, vitamins, enzymes that help digestion and antioxidants. Furthermore, sprouted quinoa has a high protein content and a low concentration of saponins. Previous studies have shown that sprouted quinoa has shown an increase in protein, calcium and ascorbic acid content. Quinoa sprouts improve the organoleptic characteristics of quinoa grains; few studies have used sprouted quinoa in the preparation of beverages. The objective of this study was to prepare a beverage based on sprouted quinoa using a simplex lattice mix design to determine the optimal formula. Three varieties of sprouted quinoa were used: white (Salcedo INIA), red (INIA-415 Pasankalla), and black (INIA 420-Negra Collana). The quinoa was incubated at 30°C in the dark for 48 hours at a relative humidity of 98%. Ten treatments with different proportions of the three types of sprouted quinoa were used. The antioxidant capacity and consumer satisfaction of the ten treatments were evaluated. The ABTS method was used to measure the antioxidant capacity of each treatment. The optimal drink mix was composed of 81.67% sprouted black quinoa, 18.33% sprouted white quinoa, and 0% sprouted red quinoa. Furthermore, the consumer acceptability results were similar across all treatments (p&gt;0.05). A nutritional analysis revealed significant differences (p&lt;0.05) between the optimized drink and the control treatment. The microbiological analysis demonstrated that the formulated drink met the required sanitary norms for aerobic mesophiles, coliforms, molds, yeasts, and absence of Salmonella. The quinoa beverage made from three varieties of germinated quinoa represents a novel alternative to the current drinkable products marketed in Peru due to its nutritional content, antioxidants, and ease of preparation. Key words: Sprouts, Chenopodium quinoa, ABTS, Design-expert, Mixture design, antioxidant capacity, acceptability

The role of the HERG channel in the secretion of glucagon-like peptide-1 (GLP-1) from murine intestinal L-cells

The HERG ion channel belongs to the voltage-gated potassium (Kv) channel family and is involved in potassium efflux during cellular repolarization. Mutations in HERG have been linked to long QT syndrome, which is associated with elevated secretion of glucagon-like peptide-1 (GLP-1). However, the precise contribution of HERG to GLP-1 secretion remains unclear. In this study, we demonstrate the expression of HERG in GLP-1-producing L-cells within the intestinal epithelium of rodents. Using a mouse L-cell model (GLUTag cell line), we observed that downregulation of HERG led to a significant prolongation of action potential duration, an increase in intracellular calcium concentration, and a stimulation of GLP-1 secretion following exposure to nutrients. These findings provide evidence that HERG plays a direct role in regulating GLP-1 secretion in the intestine and may hold promise as a potential target for the treatment of diabetes.

Effects of eggshell and seashell powder as natural dietary calcium supplements on growth, molting frequency, and carapace calcium composition of juvenile red claw crayfish, Cherax quadricarinatus.

The growth performance of red claw crayfish, Cherax quadricarinatus, fed diets with different sources and concentrations of natural calcium was evaluated. Formulated diets containing 30% protein and 8% lipid were prepared using supplementation of 0 (control), 3%, 6%, 9% eggshell, and 6% seashell. C. quadricarinatus juveniles with an average total weight of 0.21 ± 0.01 g and length of 25.0 ± 0.10 mm were obtained from ten ovigerous females bred in captivity. An aquarium with a size of 0.72 m² was divided into eight compartments with an area of 0.09 m² per compartment and was individually stocked with juvenile crayfish. A total of eight juvenile crayfish were used per dietary treatment. There were five dietary treatments in total and each of these treatments were replicated three times. The addition of eggshell and seashell powder exerted positive effects on the growth performance, molting frequency, and survival of the crayfish. Crayfish fed with a 6% eggshell-supplemented diet exhibited the best overall growth performance. The calcium percentage of the carapace increased with the increase in calcium content of the diets. Meanwhile, the performance of diets comprising eggshells and seashells was not significantly different (P > 0.05). Considering the low cost and abundance of eggshells, the addition of 6% of this product to the diet is recommended for the best growth of juvenile C. quadricarinatus.

Phosphorus May Induce Phenotypic Transdifferentiation of Vascular Smooth Muscle Cells through the Reduction of microRNA-145.

Phosphorus is a vital element for life found in most foods as a natural component, but it is also one of the most used preservatives added during food processing. High serum phosphorus contributes to develop vascular calcification in chronic kidney disease; however, it is not clear its effect in a population without kidney damage. The objective of this in vivo and in vitro study was to investigate the effect of high phosphorus exposure on the aortic and serum levels of miR-145 and its effect on vascular smooth muscle cell (VSMCs) changes towards less contractile phenotypes. The study was performed in aortas and serum from rats fed standard and high-phosphorus diets, and in VSMCs exposed to different concentrations of phosphorus. In addition, miR-145 silencing and overexpression experiments were carried out. In vivo results showed that in rats with normal renal function fed a high P diet, a significant increase in serum phosphorus was observed which was associated to a significant decrease in the aortic α-actin expression which paralleled the decrease in aortic and serum miR-145 levels, with no changes in the osteogenic markers. In vitro results using VSMCs corroborated the in vivo findings. High phosphorus first reduced miR-145, and afterwards α-actin expression. The miR-145 overexpression significantly increased α-actin expression and partially prevented the increase in calcium content. These results suggest that miR-145 could be an early biomarker of vascular calcification, which could give information about the initiation of the transdifferentiation process in VSMCs.

Synthesis of CaCO3/Cu2O/GO Nanocomposite Catalysts for Hydrogen Production from NaBH4 Methanolysis

The synthesis of CaCO3/Cu2O/GO nanocomposites was developed by sol-gel auto-combustion method. The analysis of structure was completed on X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and environmental scanning electron microscopy (ESEM). The XRD spectra of the nanocomposites matched the crystal structure of CaCO3/Cu2O. The average crystal size was 20 nm for Cu2O and 25 nm for CaCO3 nanoparticles. FTIR data showed the absorption bands of Cu2O and GO. Raman spectroscopy data confirmed the formation of GO sheets. ESEM micrographs displayed spherical nanoparticles dispersed in GO sheets. X-ray photoelectron spectroscopy showed the peaks of Cu 2p, O 1s, C 1s, Cu 3s, and Ca 2p. The spectra of optical absorption revealed an absorption band of around 450 nm. The calcium content increase led to a decrease in the optical energy gap from 2.14 to 1.5 eV. The production of hydrogen from NaBH4 across the methanolysis reaction was accelerated by the CaCO3/Cu2O/GO nanocomposites. Therefore, these nanocomposites are superior in catalytic hydrogen production systems.

Feasibility of laser-induced breakdown spectroscopy to elucidate elemental changes in human tooth ankylosis

Tooth ankylosis is a pathological condition associated with the loss of physiological tooth mobility when the firm fusion between the alveolar bone and the tooth root occurs. Causes of dental ankylosis are uncertain, so the analysis of elemental distribution in ankylotic and surrounding tissues could provide additional information about its initiation and progression. Here, we used Laser-Induced Breakdown Spectroscopy (LIBS) to determine differences in the mineral composition among ankylotic tissue, bone, and dental tissue taking advantage of its high throughput and multi-elemental capability. Elemental imaging was performed with a spatial resolution of 30 μm to evaluate the distribution of carbon, calcium, magnesium, phosphorus, and strontium in human tooth. To further verify the difference in the mineral composition of ankylotic tissue, the semi-quantitative content of these elements was compared within the region of interest. We revealed a significant increase in calcium, magnesium, and phosphorus contents in the ankylotic tissues. However, the contents of magnesium and phosphorus were not significantly changed. This finding suggests a mineral disbalance only of just certain elements in the tooth-bone interface area during the spread of ankylosis associated with an intense calcification of connective tissue. This paper brings a feasibility study and shows the way of LIBS data interpretation. We propose that the LIBS analysis on a micro-scale can contribute to the understanding of ankylotic tissue composition and can distinguish even small differences of carbon, calcium, magnesium, phosphorus, and strontium contents on the tooth-bone boundary during the initiation of ankylosis. Therefore, it represents a new useful tool for their future, more extensive analyses.

#4331 UPREGULATION OF ADIPOSE TISSUE FATTY ACID-BINDING PROTEIN 4 IN PATIENTS WITH CHRONIC KIDNEY DISEASE: IMPLICATIONS FOR DYSFUNCTIONAL VASCULAR CELLS

Abstract Background and Aims FABP4, a fatty acid-binding protein, is predominantly expressed in adipose tissue (AT) and has been shown to be elevated in patients with chronic kidney disease (CKD). Although elevated levels of FABP4 have been linked to cardiovascular disease in end-stage renal disease (ESRD) patients, the cause of this increase is unclear. The aim of this study was to evaluate the expression of AT FABP4 under uremic conditions and its impact on the function of macrophages and vascular smooth muscle cells (VSMC). Method We measured the levels of FABP4 in the blood and urine of CKD patients. The expression of AT FABP4 under uremic conditions was analyzed using omental AT obtained from healthy kidney donors and patients with ESRD who received peritoneal catheter insertion. The effect of FABP4 on the function of macrophages and VSMC was also assessed. Results The levels of FABP4 in the blood and urine of CKD patients were inversely correlated with their estimated glomerular filtration rate (eGFR). An increase in FABP4 in the blood was detected before its increase in the urine. FABP4 expression was found to be higher in mature adipocytes in visceral AT compared to the stromal vascular fraction (SVF). Adipocytes treated with p-cresol and adipocytes isolated from CKD patients showed higher levels of FABP4 expression compared to healthy individuals. Single-cell RNA sequencing of SVF showed increased FABP4 expression in progenitor cells and macrophages from CKD patients. In THP-1 cells, FABP4 induced more foam cells and increased levels of inflammatory mediators in the presence of palmitic acid. VSMC treated with p-cresol or VSMC isolated from CKD mice induced by an adenine diet showed a pro-calcific phenotype, as indicated by increased calcium content and bone-related gene expression, which was further enhanced by FABP4. Conclusion The elevated levels of FABP4 in CKD patients are not solely a result of decreased renal clearance but also due to increased production in AT. These higher levels of circulating FABP4 may be associated with dysfunction in vascular cells.

Role of Calcium-Activated Potassium Channels in Proliferation, Migration and Invasion of Human Chronic Myeloid Leukemia K562 Cells.

Calcium-activated potassium channels (KCa) are important participants in calcium signaling pathways due to their ability to be activated by an increase in intracellular free calcium concentration. KCa channels are involved in the regulation of cellular processes in both normal and pathophysiological conditions, including oncotransformation. Previously, using patch-clamp, we registered the KCa currents in the plasma membrane of human chronic myeloid leukemia K562 cells, whose activity was controlled by local Ca2+ entry via mechanosensitive calcium-permeable channels. Here, we performed the molecular and functional identification of KCa channels and have uncovered their role in the proliferation, migration and invasion of K562 cells. Using a combined approach, we identified the functional activity of SK2, SK3 and IK channels in the plasma membrane of the cells. Selective SK and IK channel inhibitors, apamin and TRAM-34, respectively, reduced the proliferative, migratory and invasive capabilities of human myeloid leukemia cells. At the same time, the viability of K562 cells was not affected by KCa channel inhibitors. Ca2+ imaging showed that both SK and IK channel inhibitors affect Ca2+ entry and this could underlie the observed suppression of pathophysiological reactions of K562 cells. Our data imply that SK/IK channel inhibitors could be used to slow down the proliferation and spreading of chronic myeloid leukemia K562 cells that express functionally active KCa channels in the plasma membrane.

Hole and Electron Doping Outcomes in Bi2YO4Cl.

Recognizing the deficiency in the hole and electron doping outcomes in layered bismuth-based oxyhalides intergrowths, the current study was addressed to the doping of Ca2+ and Zr4+ for Y3+ in Bi2YO4Cl. The samples were rapidly synthesized by a sol-gel auto combustion method and characterized extensively. Up to 30 mol % Y could be substituted with Ca in tetragonal symmetry and without the appearance of any additional phase. The unit cell parameters varied nonlinearly with the elongation of the Y-O bond. The Raman spectra supported the local site distortion. The calcium-substituted samples displayed selected area electron diffraction characteristics similar to those of Bi2YO4Cl. A blueshift of the absorption edge was noticed with increasing calcium content yielding optical band gap values in the 2.40-2.57 eV range. The creation of 10% Bi5+ in Bi2Y0.70Ca0.30O4Cl was established with the help of XPS measurements and redox titrations. The higher reactivity of Bi5+ in an aqueous solution has been demonstrated for the oxidation of As(III) to As(V). Electron doping through Zr4+ incorporation was possible up to 30 mol % in Bi2YO4Cl. The Y-O bonds are contracted, and the Bi-O bonds are elongated with increasing Zr4+ content. Zr4+'s incorporation induced a local distortion. The color of the sample changed from bright yellow to deep yellow with Zr inclusion, resulting in a progressive decrease in optical band gap values. The introduction of electrons caused the reduction of 13.6% of Bi(III) to Bi(0). These results have established the vulnerability of Bi2O2 chains to charge carriers in Bi2YO4Cl. Density functional theory (DFT) calculations were implemented to understand the electronic and optical properties of the pristine and doped compounds. From the band structure calculations, the chosen compounds were found to be indirect band gap semiconductors. The results of the DFT calculations were in good agreement with the experiment; however, for the doped cases, virtual crystal approximation has been used considering uniform doping at the Y-site.